ucid
stringlengths 13
16
| doc_number
int64 3.02k
1.99B
| country
stringclasses 2
values | kind
stringclasses 6
values | lang
stringclasses 4
values | date
float64 19.8M
20.1M
| application_date
int64 1.98k
1.99k
| date_produced
float64 20.1M
20.1M
| status
stringclasses 1
value | main_code
stringlengths 4
7
| further_codes
stringlengths 4
176
⌀ | ipcr_codes
stringlengths 5
439
⌀ | ecla_codes
stringlengths 6
2.19k
⌀ | title
stringlengths 3
460
| abstract
stringlengths 25
14.9k
⌀ | description
stringlengths 54
959k
⌀ | claims
stringlengths 7
237k
⌀ | applicants
stringlengths 3
514
⌀ | inventors
stringlengths 4
1.47k
⌀ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
WO-1979000044-A1 | 1,979,000,044 | WO | A1 | XX | 19,790,208 | 1,979 | 20,090,507 | new | G01N33 | G01N31 | C12Q1, G01N27, G01N33 | C12Q 1/00, G01N 27/447, G01N 33/558 | METHOD FOR THE DETERMINATION OF BIOLOGICAL SUBSTANCES BY DIFFUSION IN A POROUS MATRIX OR BY ELECTROPHORESIS | A method for the determination of the quantity and type of a biological component A in a sample which is added to a basin in a liquid-saturated, porous matrix covering a thin layer of a biologically active component B bound to the solid surface of a carrier. A further biologically active component C included in the matrix is capable of reacting biospecifically with component A when the sample is allowed to diffuse or migrate electrophoretically in the matrix forming a zone containing a precipitate of components A and C. This precipitate will adsorb with biospecificity to component B, bound to the solid surface of the carrier and is visualized in a suitable manner on the surface after removal of the said porous matrix, eg. as a change in the surface tension angle observed with the aid of vapour condensation on the surface. Components B and C or B and A may be the same as long as the remaining component is capable of reacting with both the others. The components A, B and C may be antigens and antibodies. The carrier is suitably made of plastic material. | A biological indicator systemThe present invention relates to a biological indicator system based on a two-phase system, in which a first biologically active component is bound to the surface of a solid phase, and a liquid- saturated immobilized phase covering said surface containing a second biologically active component, capable of reacting with onunknown third biologically active component added to the immo¬ bilized phase and permitted to diffuse or migrate electrophore- tically during formation of a zone containing a precipitate, and where the first biologically active component is capable of reacting by absorption with said precipitate formed in the im¬ mobilized phase. The presence of the third component is visua¬ lized in a suitable manner on the surface, after removal of said immobilized phase.Serologic testing methods have a central position within the diagnostic techniques of medicine and applied biochemistry in general. This is predominantly due to the fact that such methods afford the possibility of determining minute quantities of the specific reactants in question in complex systems. Within sero- logy there is utilized the basic fact that antibodies (ab) can specifically react with antigen (ag)„When indicating ag-ab-reactions, there are used different secondary manifestations capable of being indicated in various ways. One common method of indicating these reactions is the pre¬ cipitation technique, in which precipitates are formed under cer-OMPI tain conditions when soluble antigens and anti-bodies come int contact with one another. In certain cases, for example when t antigen is in particle form, agglutination reactions can be ut lized, these reactions occurring when antibodies come into con tact with the antigen.In recent years, different types of markers have been use for determining ag-ab-reactions. The markers comprise radioact isotopes, enzymes or fluorescent substances which are bound either to the antigen or to the antibody. Indication is then e ted by means of the markers in the antigen-antibody-complex, s sequent to separating said complex from non-bound antigen or a ti-bodies and accompanying markers,A specific position is held by the biological determinati methods, in which a natural biological effector mechanism is u lized to indicate the antigen-antibody reaction. Among these i dication methods can be mentioned complement-binding reactions and different types of neutralizing reactions of biologically tive antigenic substances by blocking, for example with virus, toxins and the lil^e. Antigen-antibody reactions can be quantified in different ways, by using different indication principles. The most simpl of these is the end-point titration method, in which one.part of an antigen-antibody system is diluted to a limit at which t indicator system can no longer indicate the reaction. Another method is one in which indication by means of mar kers is used, it being necessary to separate the antigen-anti¬ body complex* The amount of labelled reactants in the antigen- antibody complex or in the residue of the system separated the from is then determined, According to one conventional method, one of the reactant in an antigen-antibody system is incorporated, for example, in agargel. The other reactant is supplied in basins disposed in gel. After some time has lapsed, a radial diffusion gradient is formed by the supplied reactant. The diffusion gradient thus for¬ med is indicated, and the obtained quantification is determined by measuring the area of the circular -indication thus formed. It is also known to have the known reactant in the ag-ab-system added to a surface below the gel phase. After diffusion and migration the unknown reactant will.react with the known reactant on the surface, where it can be visualized after removing the gel phase. Indication and quantification of antigen, utilizing known anti-bodies are carried out within the field of medical diag¬ nostics and in the follow-up various diseases.The quantification of an unknown antigen with the. aid of known antibodies is effected by immunizing a living organism having the ability to form antibodies against said antigen, where¬ after it is possible, with the aid of these antibodies, quanti¬ tatively to determine the antigen with which the organism has been immunized. This method has been widely used when quantifying different human serum proteins of the type im unoglobulin and en- zymes. In latter years it has also been possible to follow up and diagnose tumouroυs diseases by determining antigens speci¬ fic to tumour cells. It has also been found that antibodies can be produced against small molecules having a molecular weight of less than 1000, enabling different types of medicaments and hor- mones to be shown in serum with the aid of antibodies, for example. The present invention is suitable for the detection of a.-fe- to-protein, IgG, IsM, IgA, IgE, hepatitis antigen, acute-phase protein, HCG (pregnancy test) and serum proteins in general.It has now been discovered that an extraordinarily sensitive and readily applied method for determining the quantity and type of biologic substances of the kind in which a component selected from the groups proteins, polysaccarides, nucleic acids, lipides or complexes thereof reacts ahd where the result of the reacti is visualized it^ situ with the aid of a component bound to a surface of -a solid phase, which is. characterized by a system,>- co prising a first biologically active component bound to the solid surface, and a liquid-saturated immobilized phase locate at said surface, said phase containing a second biologically a tive component, to which is added a test aliquot possibly cont ing a third biologically active component, which is to be. de¬ termined, said third component being capable of reacting with the second biologically active component during formation of a precipitate existing of equivalent concentrations of the secon and the third component, said precipitate being capable of rea ing with the first biologically active component and by the th biologically active component being permitted to diffuse or migrate electrophoretically and form a precipitate with the se biologically active component, said precipitate reacting with the first biologically active component by removing the immobi lized phase, and by reaction between said precipitate and the first component thus being arranged for observing an indicatio of the presence and quantity of the third component on said so surface in any suitable manner.The proteins may comprise immunoglobulins such as antibod and antigens and other antigenic substances, such as enzymes, toxins, lectines and hormones or systems which form precipitat of the type defined as an equivalent zone precipitate, i,e. where a precipitate is formed when concentration of said secon component and said third component are substantially equivalen and therefore forms a moving front of precipitate which is re- split when the concentration of the third biologically active component is increased.Examples of the polysaccarides include lipopolysaccarides such as gangliocides, endotoxin, mucopolysaccarides, glycoprot Among the lipides, different lipide complexes can be used, such as cardiolipides. Among the nucleic acids, desoxyribonucleic acid has an antigen activity and can be used as a component on the plastics surface. The thin layer of said first component is suitably applied to the plastics surface in the following manner: a liquid medium, suitably based on water, is first dispensed onto the plastics surface, whereafter a solution containing the component is added to the liquid medium to diffuse therein, whereafter the compo- nent is permitted to deposit itself onto the plastics surface, becoming boand to the plastics surface with a force of such mag¬ nitude that said surface can be washed without the layer being removed therefrom, subsequent to the aqueous' medium having been removed. The solid surface is suitably a transparent material, such as glass, or a plastics material, e.g.' polystyrene, polyacrylo- nitrile, polyolefines and copolymers thereof.It has been found in recent years that plastics surfaces ad¬ vantageously adsorb macro-molecules to form very uniform and re- producable layers. A technique for visualizing antigen-antibody reactions is one in which a thin layer of indium particles is vapor-deposited on a glass surface. The antigen-antibody reactions are carried out on the indium layer, whereafter the reactions can be observed as a light-propagation phenomena on the indium surface. The most serious disadvantages with this technique appear to be the requirement of advanced apparatus for producing a uni¬ form and reproducable layer of indium on large surfaces. This< < restricts the rational use of such surfaces. Furthermore, it is difficult to classify a reaction as a positive or a negative one, in borderline cases, since this indicator system has a flat amp- litude and the indication can only be judged subjectively.1 Anothe'r, much simpler technique for visualizing adsorbed precipitates on solid surfaces is one employing the condensation of water vapor. This technique involves exposing the dried sur¬ face to vapor, whereupon it is possible to determine whether a reaction has taken place and the extent of any such reaction fro the pattern formed by the condensation. The principles of this technique were described by Langmuir in 1936, This method is as sensitive as the method employing an indium layer, but has a steeper indication-amplitude. Moreover, it permits the objective analysis by contact-copying of the condensation pattern on the surfaces by irradiation of photographic paper and development thereof.The indication of ag-ab-reactions is thus best effected wit vapour condensation on the plastics surface (Vapour condensation on surface, VCS, see Adams, Klings, Fisher and Vro an, Journal of Immunological Methods, 3, (1973) pages 227-232), which, be- cause of its simplicity, is the preferred method. Other known methods can also be used, such as the' so-called ELISA-method (Enzyme-linked im unosorbent assay, J. Immun. 109:129. (1972), mixed haemadsorption (immunology 9:161 (1965) ), particle adsorp tion technique, using a slurry of barium sulphate,for example immunofluorescense, various colouring techniques and auto-radio¬ graphy with isotope-labelled serological reagents.The reason why it is possible to observe a change as a re¬ sult of adsorption of precipitates on the molecular layer on the plastics surface as a result of vapour condensation is due to the fact that the so-called Zeta-potential or surface tension against condensed drops of water is changed on the surface when an adsorption reaction has taken place. Such changes are macro- scopically visible in the light-scattering phenomena of the όon- densation pattern. In principle, all hydrophobic surfaces have a surface-tension angle of from 90 to 170 , Those plastics sur¬ faces which normally hve such properties include polystyrene, polyacrylnitril, polyethylene and copolymers thereof. An immobilized matrix through which the unknown substance shall diffuse is then applied to the surface containing a bio¬ logically active component. Such immobilized matrices are well known within the technique of analysis, and may comprise aqueous gels or various types of sediment or- fibrous substances. The most conventional method is one in which a gel is used, in particular an agar gel, suitably comprising a buffered 1^-solution of agar which is permitted to solidify, A basin is then formed in the matrix, there being supplied to the basin a solution containing the unknown component. The unknown component may also be supplied in cellulose plates or the like which have been saturated with the solution containing the unknown component. The system is left at a suitable temperature of between 5 and 50 C, for the unknown substance to diffuse from the basin, Compared with previously known methods of obtaining quan¬ titative measurements of minute quantities of biological mate¬ rials, the novel method exhibits a simplicity which has not pre¬ viously been achieved, and therewith a subsequent increase in capacity and decrease of costs. Furthermore on plastics surfaces the precipitation is very uniform and thus suitable for diag¬ nostic tests with regard to reproducibility , which is not the case with glass to the same degree. A further advantage afford¬ ed by the use of plastics is that the protein nature of the absorbed component is not denatured or chemically converted, as often happens with glass surfaces. The application of a compo¬ nent fraction by first applying an aqueous medium and then, adding the component fraction to said medium ensures that a much more uniform layer is obtained than would be the case when a protein suspension or solution is applied to the dry surface, Moreover, the amount of component fraction consumed is con¬ siderably lower when a plastics surface is used than when a glass substrate is used. Furthermore, when using a glass substrate it is normally necessary to treat the layer with formalin in or¬ der to denature the same so that it does not loosen from the gla surface. Finally, the diffusion image obtained on the plastics surface can be treated with antigen-immunoglobulin, thereby to visualize even the most minute reactions or reaction quantities • This method is based on the experience that immunological precipitation reactions take place when the quantities of antig and antibody are in a specific relationship to one another and are redissolved when one part or the other is present in large surplus quantities.In those instances in the aforedescribed method where the matrix contains the said second component in the antigen-antibo reaction, said first component having been added to the plastic surface, and the quantity of the third component is to be deter mined, it is important that said first component is not added t the surfaces in a pure form,_ otherwise an excessively large qua tity of the second component present in the matrix will bind directly to said first component on said surface as soon as the matrix is applied. In turn, this means that it is impossible, o extremely difficult to read the precipitation-print reaction wi any method. It has been found that this problem is removed by mixing said first component with unrelated substances in suitab ratios prior to adding to the plastics surface and thus thin ou the layer of said first component, The method is highly sensitive, and quantities as small as, or less than magnitudes of 10 ug/1 can be detected. It is also possible to obtain multi-precipitating systems in which classes of antibodies can be determined. The system enables less pure a tigen-antibody substances to be used. It is extremely surprisin that precipitation adsorption on the plastics surface is obtain with this technique. This is probably due to the fact that the antibodies have two binding functions, and that there is obtainOMPI<fy W1PO α bond with said first component located on.the solid surface and a further agglomerating and cross-linking bond with the antigens in the matrix. Thus, the matrix contains one or more antibodies against the antigen to be determined, and the solid surface is provided with this antigen or another antigen, whereby complex re¬ actions can be obtained.It is also possible to obtain multiple precipitation zones if said third component includes more than one biologically ac¬ tive element and if the immobilized phase containing said second component consisting of more than one element, which reacts with the respective element in the third component. The multiple zones thus obtained can be selectively combined with said first component if the latter consists of separate areas each covered with a different compound reacting with the respective preci- pitate to provide individual detection.From the above description it will be evident that the said first and said third component can be the same if the second is different and the said first and said second component can also be the same if the said third component is different, Of course, all three could be of different kinds. Thus, if said second compo¬ nent is an antibody said third component can be an antigen and said first component can be either an antibody like or unlike said second component or an antigen like or unlike said third com¬ ponent. As an example, said first component is the antigens IgG and IgA, each on its own surface area. Said second component consists of anti-IgG, anti-IgG and πnti-IgM and said third component con¬ sists of a human serum containing IgA, IgG and IgM, The serum is placed in a basin on the borderline between the. two. different surface areas of said first compound. After a suitable diffusion period three concentric precipitation lines can be observed and measured in the gel. The gel is then removed and it is possible to record the respective positions of the IgA and IgG precipitate The third precipitate is identified by exclusion as the IgM pre¬ cipitate.In another embodiment according to the invention, said first component in anti-a-feto-protein. Anti-a-feto-protein is include in the gel in such a low concentration that no'-visible precipitat can be obtained with said third component, which is a-fet -protei in human serum, a-feto-protein is an indication of primary hepa- thomas, which are types of tumours, a-feto-protein is present in very low concentration in early cases of tumours, and can thus b observed by a precipitation reaction at the surface area, where said first and said second components together form the precipitThe use of low concentrations of anti-a-feto-protein in the gel make this method more sensitive. There will only be precipi- tation if the original concentration of said third component in the sample is higher than the concentration of said second compo nent.OMPI | CLAIMS j-1, A method of determining the quantity and type of biologic substances of the kind in which a component selected from the groups proteins, polysaccarides, nucleic acids, lipides or complex¬ es thereof reacts and where the result of the reaction is visu- alized iji situ with the aid of a component bound to a surface of a solid phase, characterized by a system, comprising a first biologically active component bound to the solid surface, and a liquid-saturated immobilized phase located at said surface, said phase containing a second biologically active component, to which is added a test aliquot possibly containing a third bio¬ logically active component, which is to be determined, said third component being capable of reacting with the second biologically active component during formation of a precipitate existing of equivalent concentrations of the second and the third component, said precipitate being capable of reacting with the first biolo¬ gically active component, and by the third biologically active component being permitted to diffuse or migrate electrophore- tically and form a precipitate with the second- biologically ac¬ tive component, said precipitate reacting with the first biolo- gically active component by removing the immobilized phase, and by said reaction between said precipitate and the first compo¬ nent thus being arranged for observing an indication of the presence of quantity of the third component on said solid surface in any suitable manner, 2. A method according to claim 1, characterized in that the first biologically active component and the second biologically active component are the same.3, A method according to claim 1, characterized in that the first biologically active component and the third biologically active component are the same,4. A method according to claim 1, characterized in that the solid surface constitutes a plastics material selected from thegroups polystyrene, polyacrylnitrile, polyolefines and copolymers thereof,5, A method according to claim 1, characterized in that the re tion on the solid surface an the resultant change in the surfa tension angle are observed with the aid of vapour condensation on the surface,6„ A method according to claim 1, characterized in that the first and the second biologically active components are anti-a- feto-protein and that* the third biologically active component is a-feto-protein contained in human serum,7, A method according to claim 1, characterized in that diffe¬ rent sectors of said solid surface are covered with different components acting as the first biologically active component and that more than one component is incorporated in the immobilized phase acting as the second biologically active component and that different reactions are indicated ai different surface sec¬ tors after removing the immobilized phase,8, A method according to claim 7, characterized in that IgA and IgG are used as the first biologically active component on different sectors of said surface and that the immobilized phase contains anti-IgA, anti-IgG and anti-IgM and that the third component is human serum containing at least one of IgA, IgG and IgM.-βϋRE O P R | ELWING H | ELWING H |
WO-1979000045-A1 | 1,979,000,045 | WO | A1 | XX | 19,790,208 | 1,979 | 20,090,507 | new | G01N33 | null | C12Q1, G01N27, G01N33 | C12Q 1/00, G01N 27/447, G01N 33/558 | METHOD FOR THE DETERMINATION OF ENZYMES BY DIFFUSION IN A POROUS MATRIX OR BY ELECTROPHORESIS | Method for the determination of enzymatic activity in which a sample is added to a basin in or a defined surface of a liquid-saturated porous matrix covering a thin layer of a substance sensitive to enzymatic lysis deposited on the solid surface of a carrier. The sample is permitted to diffuse or migrate electrophoretically in the matrix and react with the substance sensitive to enzymatic lysis. The matrix is then removed whereon lysis can be indicated on the solid surface. The enzym-containing sample can be a bacteria colony on the matrix. Plastic material is preferred for the solid surface. | An enzymatic indicator systemThe present invention relates to an enzymatic indicator sys¬ tem based on a two-phase system, in which an enzyme substrate is bound to the surface of a solid phase and in which the presen¬ ce and quantity of an enzyme capable of reacting with the compound bound to said surface is determined by permitting the enzyme to diffuse from a basin in a liquid-saturated immobilized phase lo¬ cated on said surface. The presence and quantity of enzyme is then indicated on the solid phase in a suitable manner.Enzymatic types of testing methods have a central position within the diagnostic techniques of medicine, microbiology and applied biochemistry in general. This is predominantly due to the fact that such methods afford the possibility of determining minute quantities of the specific reactants in question in complex systems. Enzymatic test methods have been used in diagnosing vari¬ ous diseases by determining enzyme activity in .serum, and other biological fluids, as well as enzyme activity generated by microorganisms.These enzymatic tests are generally effected by. various indicator systems involving colour changes, lysis of cells as erythrocytes, or degradation of molecules or the like.The method according to the invention involves depositing a substrate on a solid surface as a thin layer of a substance sensitive to enzymatic lysis, whereafter there is placed on the thin layer an immobilized matrix in which the enzyme to be de¬ termined is permitted to diffuse or electrophoretically mig¬ rate during a measured period of time, whereafter the matrix is removed and the lysis reaction surface area on the solid surface is determined by adding an indicator substance, or in some other suitable way. The thin layer of said substance is suitably applied to the solid surface in the following manner: A liquid medium, suitably based on water, is first dispense^ to the solid surface,, A solution containing said substances is then added to the liquid medium to diffuse therein, where¬ after the substance is permitted to deposit itself onto the. so lid surface, becoming bound to the solid surface with a force such magnitude that said surface, subsequent to the aqueous me dium having been removed, can be washed without the layer bein removed therefrom.The solid surface is suitably a transparent material, suc as glass or a plastics material, e.g. polystyrene, polyacryl- nitrile, polyolefines and copolymers thereof. It has been foun in recent years, that plastics surfaces advantageously adsorb macro-molecules to form very uniform and reproducable layersβA technique for.visualizing enzyme reactions is one in wh a thin layer of indium particles is vapor-deposited on the sol surface. The enzyme reactions are carried out on the indium layer, whereafter the reactions can be observed as a light-pro pagation pehno ena on the indium surface. The most serious dis advantages with this technique, appear to be the requirement of advanced apparatus for producing a uniform and reproducablelay of indium on large surfaces. This restricts the rational use of such surfaces. Furthermore, it is difficult to classify in a reaction as a positive or a negative one in borderline cases since this indicator system has a flat amplitude and the indic tion can only be judged subjectively. Another]^,much simpler technique for visualizing enzymatic reactions on solid surfaces is one employin the condensation of water vapor. This technique involves exposing the dried sur face to vapor, whereupon it is possible to determine whether a reaction has taken place and the extent of any such reaction from the pattern formed by the condensation. The principles of this technique were described by Langmuir in 1936. This method is as sensitive as the method employing an indium layer, butOMPI - - has a steeper indication-amplitude. Moreover, it permits ~±he objec¬ tive analysis by contact-copying of the condensation pattsrn on the surfaces by irradiation of photographic paper and development thereof.5 The indication of biological surface reactions is tfeωs best effected with .vapour condensation on the plastics surface (Vapour condensation on surface, VCS, see Adams, Klings, Fisher and Vroman, Journal of Immυnological Methods, 3, (1973) pages 227-232), which, because of its simplicity, is the preferred method. Other10 known methods can also be used, such as the so-called ELXSA- method (Enzyme-linked immunosorbent assay, J. Immunβ 109 129 (1972), or particle adsorption technique, using a slurry of barium sulphate for example, and various colouring techniques,,The reason why it is possible to observe a change in the thin15 layer on the solid transparent surface as a result of vapour con¬ densation is due to the fact that the so-called Zeta-potential or surface tension against water is changed on the surface when a reaction has taken place. In principle, all hydrophobic surfaces have a surface-tension angle of from 90 to 170 „ Those plastics sur-20 faces which normally have such properties include polystyrene, poly- acrylnitril, polyethylene and copolymers thereof,,The substance bound to the plastics surface is able to react selectively with a further substance, either on reacted parts or on unreacted parts of the substance, and the reaction in question can25 be shown visually iri situ even when it is difficult to make the reaction directly visible on the substrate after the en__y.me reac¬ tion.An immobilized matrix through which the unknown substance shall diffuse is then applied to the surface having the antigen30 thereon. Such immobilized matrices are well known within the tech¬ nique of analysis, and may comprise aqueous gels or various types of sediment or fibrous substances. The most conventional method is π--.. one in which α gel is used, in particular an agar gel, suitab comprising a buffered lyt-solution of agar which is permitted solidify. A basin is then formed in the matrix, there being s lied to the basin a solution containing the unknown substance unknown substance may also be supplied in cellulose plates or like, which have been saturated with the solution. The syste is left at a suitable temperature of between 5 and 50 C, for unknown substance to diffuse from the basin.Compared with previously known methods of obtaining quan tative measurements of minute quantities of biological materi the novel method exhibits a simplicity which has not previous been achieved, and therewith a subsequent increase in capacit and decrease of costs. Thus, it is relatively simple to obtai uniform, thin component layers on plastics surfaces, the adhe of the layer to the plastics surface being independent of the1 concentration of the substance forming the layer in the solut applied to the surface in a sufficient quantity, as compared the adhesion forces obtained in respect of glass surfaces.The method according to the invention is thus used for e zymatic analysis of substances sensitive thereto, the plastic surface having applied to it a thin layer of an enzyme subst and an immobilized matrix over said substrate, whereafter an enzyme-containing sample quantity is applied to the matrix an permitted to diffuse therein; whereafter the matrix is remov and those parts of the enzyme substrate which have been affec by the enzyme are indicated by lysis being obtained in this r gion. The method is much simpler to carry out than known meth the latter employing reactions in a mass and chromatographic systems. A high-degree of sensitivity is achieved,which can b subscribed to the fact that a high substrate concentration is tained in the thin layer. The method provides information con cerning the diffusion properties of the enzyme, it being posIjUROM - to determine the molecular weight from the diffusion rate, if the concentration and temperature are known at the same time. The method enables the extra-cellular enzyme activity of bac¬ teria to be examined in a simple and reliable manner.gϋREA } ' #8k QMPI | CLAIMS:-1„ A method of determining enzymatic activity, characterized that there is deposited on a solid surface a thin layer of a substance which is sensitive to enzymatic lysis, whereafter an immobilized matrix is applied to the thin layer and in that th is supplied to.the immobilized matrix a quantity of an enzyme- containing sample, which is permitted to diffuse or migrate el • trophoretically in the matrix and react with the substance sen sitive to enzymatic lysis, whereafter the matrix is removed fo allowing the lysis to be indicated on the solid surface.2. A method according to claim 1, characterized in that extr cellular enzymes formed upon bacterial growth are permitted to diffuse through an immobilized matrix comprising a nutrient fo bacterial growth, and in that a lysis of the substance deposit on the solid surface is allowed to be indicated subsequent to removing the matrix.3. A method according to claim 1, characterized in that the solid surface constitutes a plastics material selected from th group polystyrene, polyacrylnitrile, polyolefines and c polyme thereof.OMPI _ WIPO | ELWING HANS BJOERNE | ELWING HANS BJOERNE |
WO-1979000047-A1 | 1,979,000,047 | WO | A1 | XX | 19,790,208 | 1,979 | 20,090,507 | new | E04B2 | E06B1 | E04B2, E06B1, E06B3 | E04B 2/82C, E06B 1/18, E06B 3/08, E06B 3/64 | CONSTRUCTIONAL MEMBER FOR BUILDINGS | The constructional member is intended for use in installations of false ceilings, walls, doors and windows in building, and is formed as a substantially U-shaped rail with a web portion (1) and two leg portions (2, 3). Since one leg portion (3) is snapable onto the web portion (1). the rail can be first placed round the member (15) which is to be erected, e.g. a partition wall, and thereafter the constructional member can be fixed in place with the help of the snap-on leg portion (3). The middle portion (5, 7, 8) of the web portion (1) has channels which enable exact fitting of the constructional member either round a building member (17) or against another constructional member, e.g. at comers or edge surfaces. The member can be fixed against the ceiling and floor at an optional location in a room, which substantially simplifies installations and alterations. Further advantages are that all installations can be carried out as pure erection work and that the material which is used in an installation can be recovered and reused on being dismantled. | Constructional member for buildingsThe present invention relates to a constructional member for buil¬ dings, preferably for use with pre-fabricated building members for false ceiling, wall, door, window and similar installations.In building technology and especially with interior decoration fit¬ tings and fixtures, the different work operations must be very care¬ fully planned today, so that the tradesmen who are to carry out the installation work on site will be of the right category for the work operation, and will be there at the right time as well. The situation becomes especially complicated for installations where tradesmen of different categories must return to the site repeatedly so as to allow other artisans to complete the parts of the building work which are a prerequisite for the next stage in the installation work. For example, electricians and plumbers must return to the site at different stages to put in wiring and pipes according as the installation of partition walls and false ceilings is completed. Such time and work planning is extremely difficult to execute, and in practice there are always- collisions between tradesmen of different categories, who then interrupt each other's work. Artisans in one category sometimes cannot start their work due to the fact that a previous building stage is not ready. In other cases tradesmen in a certain category may perhaps have omit¬ ted to make additions to their work that are required to complete a definite building stage, which means that work already. finished must be pulled down and done again. Planning building work under these conditions must obviously be extremely difficult, thus taking a lot of time as well as being expensive, not to mention how expensive incorrect planning must be for the owner of the building . In calculating building cos ts , one mus t always count o the occurrence of cost increases of this kind , and therefore these costs are also included in tenders to the purchaser.Today , there are certain electrical systems which can be install after most of the structural work has been completed , and these systems can also allow considerable flexibility with respect to placing electric light fittings , plug points and other arrange¬ ments pertinent to the electrical installation . Such systems are built up on a relatively simple basic installation , which must be put in at n early stage in building . The advantages of these known systems care naturally that in the planning stage it is not necessary to s tate in detail where power points and lighting fit tings shall be placed, and they also enable wide rearrangements of these units if it is desired to use the premises for other pu poses than those for which they were originally intended. These known electrical systems are based on standardi zed rails which c be placed in ceilings or on hangers , and which serve as cable ch nels in the ceiling. Both mains s upply and light current cables can be placed in these rails , and the bottoms of the rails are formed with attachments for lighting fittings , thus enabling a flexible lighting installation . The ceiling system can also be supplemented with lines to tables directly from each rail , and such lines 'can then be supplemented in an optional way with- earth power points and telephone j acks . These known rail systems are furthermore designed as carriers for false ceilings , and the rails are then arranged in the form of a grid, the dimensions of which are suited to the ceiling module and lighting fitting lengtPrefabricated building s labs consisting of a compressed fibrous m terial , -of the mineral wool type , on whi ch there has been placed a hard surface material , e . g . of the heavily compressed glass fib sheet type , are already known . These building s labs have extremel good heat and sound insulating pro p erties , and the hard surface material is available in a number of different colours and pat¬ terns . If so required , the surface can be covered with woven or patterned wallpaper during manufacture of the s lab .The cons tructional member according to the present invention is intended for use together with prefabricated building members of the type mentioned above. The installation of partition walls, doors and false ceilings is thus simplified, so that this work can be carried out as .a pure erection job, using prefabricated building members and utilizing the inventive constructional member. The building members as well as the constructional members arrive on site in a finished condition, for putting together with bolted joints. This means that the entire installation of interior fix¬ tures can be carried out by one single category of artisans, who do not need to be trained in joinery or bricklaying, since such work does not need to be involved.The inventive constructional member can. also be used to advantage in conjunction with the electrical system described above, the electrical system thus being simplified to a great degree, and the installation of false ceilings and partition walls can be co¬ ordinated with that of laying electrical cables from the ceiling rails at the rate at which erection work is carried out.These objects are substantially realized in that a substantially U-shaped basic rail comprises a basic web portion and two basic leg portions, the middle portion of the basic web being formed with supporting and anchoring means for connecting building mem¬ bers, and that at least one basic leg portion is removably at¬ tached to the basic web portion.With the inventive constructional member, substantial advantages are obtained in the form of shortened planning time, as well as very much, simplified building construction in essentially two stages. The first stage consists of the finished building struc¬ ture, i.e. all concrete work has been done and the main struc- tures of the building are ready. In general it is then possible for concrete workers and carpenters to leave the site, and the installation of false ceilings, partition walls, interior deco¬ rating fittings and fixtures, electrical installation etc. is be¬ gun. During this latter stage, the whole installation can be car¬ ried out using building members and the inventive constructional member and, as already mentioned, the work can be carried out by a single category of tradesmen trained in electrical installation and erection. Apart from the above-mentioned advantages obtained with the in¬ ventive constructional member, a flexible interior is also achi¬ eved, which can be easily altered and suited to individual requi ments.Since interior work can be mainly carried out by a single cate¬ gory of tradesmen, planning work is -also facilitated, and good coaction between different environmental components such as ligh air and sound can be obtained at the site as early as the plan¬ ning stage. The supply and erection of all interior building mem bers such as false ceilings, partition walls, screens and lighti fittings can be carried out by the same supplier, who also answe for the erection work.Since the entire interior installation is built up from prefabri cated members, dismantling will naturally also be simplified and both walls and ceiling members can be re-used.Some embodiments of the inventive constructional member, selec¬ ted as examples to demonstrate its use, are described in detail below while referring to the accompanying drawings on which Figure 1 is a cross section of a basic rail according to the in¬ vention, Figure 2 is a cross section of a leg portion which is removably connected to the basic web portion,Figure 3 is a cross section of two additional rails attached to a basic web portion according to Figure 1,Figure 4 is a cross section through a partition wall with a basi web portion arranged as ceiling support for the wall, Figure 5 is a longitudinal section through a corner portion of a door frame according to Figure 6 ,Figure 6 is a horizontal section through a partition wall with a door frame and door leaf built up from the inventive construction member,•Figure 7 is a cross section through the connection to the floor o the partition wall in Figure 4,Figure 8 is a cross section through the partition wall and door i Figure 6, Figure 9 is a cross section through a screen wall built using the inventive constructional member,Figure 10 is the upper side of the screen wall in Figure 9, Figure -11 is a cross section through a- ceiling connection for a glass wall, whe- the- glazing is fixed by means of an inventive constructional member,Figure 12 is a horizontal section through the glass wall,* inclu¬ ding pillars made up from the constructional member, Figure 13 is a cross x section through the floor connection of the glass wall in Figure 12,Figure 14 is a horizontal section through a window structure built up from the inventive constructional member, containing insulating glazing and ordinary window glazing with window frames and sealing Figure 15 is a beam built up from the inventive constructional ele - ment and Figure 16 shows an alternative beam structure.Figures 1 and 2 show the parts, which together form a basic rail according to the invention. The rail thus comprises a basic web portion 1 and two basic leg portions 2 and 3, one part of the ' basic web portion being formed as an attachment for the basic leg portion 3, which is thus movably attached to the basic web portion 1. The basic rail is further formed with supporting legs 4 and anchoring means in the form of a substantially I-shaped sec¬ tion with a- web portion 5 and flanges 7, 8, 9 and 10. Together with the basic web portion 1 the legs 2 and 3 define a first chan¬ nel in which a building member, e.g. a wall slab, is introduceable with a suitable fit, as is apparent from Figures 4 to 14. With the anchoring web portion 5, the anchoring flanges 7, 8 and 9, 10 form two channels, one on either side- of the rail, into which attaching members are fixable. One type of attaching member is shown in Fi¬ gure 3, .and consists of a supplementary rail 11 provided with re¬ silient means 12 for engagement with the ends of the anchoring flanges 7, 8 or 9, 10.As is apparent from Figure 4, the insides of the support legs 4 and the basic web portion 1 form a third channel, in which a buil¬ ding element such as a wall slab 13 can be introduced with a suit¬ able fit. The basic rail 1, 2, 3 is attached to the wall slab 13 by means of a screwed connection 14, and the first channel, i.e. the one formed by the basic web portion 1 and the basic leg por¬ tions 2 and 3 accomodate another wall slab 15, constituting the ceiling connection for a partition wall. The floor connection is apparent from Figure 7, where the support legs 4 are facing to¬ wards the floor and are fixed sideways by means of wall-to-wall carpeting or a similar soft floor covering, while the first chan¬ nel accomodates the lower part of the wall slab 15. In the centre of the wall slab there is another tubular attaching member 17, fi ting into the second channel formed by the anchoring web portion 5 and the anchoring flanges 7 and 8. This attachment member is forme as a tube, preferably from metal, which locks the wall structure sideways simultaneously as it constitutes a stiffening element in the wall. The cross section of the attachment member 17 can be seen in Figure 6.The horizontal section through the position wall and door in Fi¬ gure 6 illustrates the door frames, consisting of basic rails 1, 2, 3, fixed to their respective wall slabs 15 by means of screwed connections 14 in the member 17. As is apparent from the figures, there is a supplementary rail 11, 12 fixed into the second channel of the basic rail 1, 2, 3, while the attachment member 17 is in¬ serted in the other second channel facing the opposite direction. The ends of the legs of the supplementary rail position the sealin elements 18 and 19, lying in the third channel of the basic rail with a pinching effect. The opposite side of the door frame is put together in a similar way, excepting that the supplementary rail 11, 12 constitutes the attachment for one part (20) of a hinge, th other part (21) of which is attached to the door leaf. The edge finishing.of the door leaf consists of the same supplementary rail wh;j.ch simplifies to a great degree the assortment of rails which must be kept in stock for use in different installations. The tu¬ bular attachment members 17 also serve as channels for electric cables, laid in a ceiling rail (not shown) . Fitting power points is thus- done by drilling a hole at the desired place in the tu¬ bular member 17, and the cable drawn down from the ceiling rail can be taken out for' connecting to the socket, which can then be screwed into place. Figure 5 shows the joint between one side mem¬ ber and the upper member of the door frame, using an angle piece 6, which can be introduced into the partially closed duct formed by the anchoring web portion 5 and each of the anchoring flange pairs 7, 8 and 9, 10. The angle piece is fixed into the duct by means of screws which are screwed against the web portion 5, to lock the angle piece against the edges of either flange pair by clamping action.From the cross section of the door of Figures 4, 6 and 7, shown in Figure 8, it is apparent that threshold as well as upper door frame are built up in a similar way as the frame sides in the other figures. The attachment members 17 are thus arranged as a frame in the side members of the door frame and the upper member, and serve 'as attachment for the screwes fixing the basic rails to the supp¬ lementary rails. The door threshold is thus fixed lengthwise and in height by means of the side members of the door frame, while transverselly it is fixed by the engagement of the support legs 4 against the substructure. In the channel between the leg por¬ tions 2, 3 and the web portion 1, there is a filler body 22, and the whole threshold is encased in a decorative and durable casing 23. The lower edge of the door is provided with a seal 24, attached in a simple manner to the lower supplementary rail 11, 12.The screen wall shown in Figure 9 is also built up from prefabri¬ cated wall slabs 15 and attachment members 17, fixed into a basic rail 1, 2, 3 according to the invention. The basic rail accomodates the pivoting mechanism 25 of the folding wall, and also the roun¬ ded portions 26 enabling effective sealing between the wall slabs, independent of the mutual attitude between them. Figure 10 shows the upper side of the screen wall, which has been provided with a fitting consisting of the basic rail 1, 2, 3-, to which a supplemen¬ tary rail 11, 12 has been attached.Figures' 11-13 show an interesting application of the inventive constructional member. It is possible to utilize the basic rail for glass walls as well as window structures, where of course the wall structure is the simpler one in practice. Figure 11 is a cross section through the connection of the glass wall to an up¬ per wall portion, which as with previous structures, consists of a wall member 15 and attachment rail 17, each acco odated their respective channels on the basic rail 1, 2/ 3. The second channel 9, 10, 5 receives a supplementary rail 11, 12 between the corners of which and the respective adjacent supporting leg 4 there is a sheet of glass 27. Figure 12 shows the glass wall in plan, where the lefthand portion constitutes a connection to a side wall 15, while the righthand portion consists of a pillar, comprising two mutually facing basic rails 1, 2, 3 , 1 , 2 *, 3', which are fitte round a supporting body 28, e.g. a steel tube to give the struc¬ ture its carrying capacity. Figure 13 shows the floor connection of the glass wall, where the sheets of glass 27 rest against elas tic support elements 29, and where possible gaps between the glas and the constructional member are shown filled'with sealing ma¬ terial 30.Figure 14 is a cross section through a window formed with tripple glazing, the- two outer sheets of glass consisting of an insulatio panel 30, rigidly mounted in the window frame, while the inner glazing sheet 32 is hinged. The window is mounted in a frame con¬ sisting of a basic web portion 1, a fixed leg portion 2 and a removable leg portion 3a-. or 3b, the latter two including a hinge portion 33 and a locking portion 34, respectively. One of the sup port legs 4 engages against the outside of the fazade, while the other is accommό.±ed in a groove in the window wall 36. When the - window is fitted, the cavities in the constructional members are suitable filled with a foam plastics material to improve insulati and prevent the occurrence of cold bridges through the frame mem¬ bers. The web portion is provided with holes 38 for further pre¬ venting the occurrence of cold bridges and to allow the foam ma¬ terial to come into all the cavities in the rail. The insulation panel 31 and the inner seals 32 'are kept ±v.place by means of supp lementary rails, the width of which are adjustable to suit the me bers positioned by means of clamping action against the leg por¬ tions of the basic rail.In Figure 15 will be seen the principle for a beam structure in which two basic rails are fitted to each other to form a beam section. In this case the surfaces facing each other of the basic supporting legs 4 form a U-section together with the basic web portion,1, this U-section fitting the first channel on another basic rail. Figure 16 shows an alternative beam structure where the basic rails are attached to a support body 28 arranged in the first channels of two basic rails, the leg portions 2 and 3 of which are facing each other. Another support body 39 is ar¬ ranged in the third channel to one of the two basic rails and the third channel of a further basic rail, the support legs 4 of both last-mentioned basic rails facing towards each other. Using this assembly pattern, an entire wall can be built up using the in¬ ventive constructional member. | CLAIMS r1. A cons ructional member for buildings , preferably for use prefabricated building members for false ceiling, wall , door, w dow and similar installations , characterized in that a substant -U-shaped basic rail comprises a basic web portion and two basic portions , the middle part of the basic web portion being formed with supporting and anchoring means for connecting building mem¬ bers , and that at least one basic leg portion is removably atta to the basic web portion .2. A member as claimed in claim 1 , characterized in that the choring means are arranged so that together with the basic leg p tions they define a first channel in which a building member can be accommodated with a suitable fit.3. A member as claimed in claims 1 and 2 , characterized in tha the basic support means are directed in the same direction from the basic web portion and that together with the basic web .por- tion their surfaces facing away from each other form a U-shaped beam which can be accommodated in the first channel on another basic rail .4 . A member as claimed in claims 1 and 2 , characterized in tha the anchoring means have a substantially I-shaped cross section , and that the anchoring flanges together with the anchoring web portion define two second channels , one on either side of the web , in which attaching members may be fixed.5. A member as claimed in claim 4 , characteri zed in that an at taching member consists of a supplementary rail which is attacha in the opposing second channels with the help of spring means , e gaging with the ends of the anchoring, legs . 6 . A member as- claimed in claims 1 and 5 , characteri zed in that the basic support means are directed in the same direction and that together with the basic web portion their surfaces facing towards each other are. intended to form a third channel .7. A member as claimed in claims 2 and 5 , characterized in that the supplementary rail has a width so adj sted that in its attach¬ ment to either of both the other channels there are gaps between the ends of the supplementary rail and opposing portions of the basic rail , said portions consisting either of the support means or of the leg portions , whereby building details of different kinds can be attached with clamping action in the gaps , and that the width of the supplementary rails is adj ustable with respect to the building details which are to be attached in the gaps .8. A member as claimed in claim 1 , characterized in that the re¬ movable basic leg portion has a U-shaped groove , the side por¬ tions of which are arranged to engage resilitently with two fork¬ like projections on the end part of the basic web portion .9 . A member as claimed in claim 4 , characterized in that another attaching member consists of a tubular locking bar, insertable in a cavity in the building member , the edge of which is insertable into the second channel with a suitable fit. AMENDED CLAIMS - (received by the International Bureau on 24 November 1978 (24.11.78))1. A constructional member for buildings, preferably for use with pre¬ fabricated building elements used in ceiling, wall, door, window and similar installations, comprising a base rail (1,2,3) with a substantially U-shaped c section having a -web portion (1) and two leg portions (2,3) of resilient mater e.g. aluminium or hard plastics, one of said leg portions (3) being releasiπgl attached to one end of the web portion (1) by means of resilient engagement between latching members arranged on these portions, characterized in that the base rail is provided with two supporting limbs (k) opposingly directed in rel to the leg portions (2,3), the outer distance between the supporting limbs (4) corresponding to the inner distance between the leg portions (2,3), so that th base rails can fit into each other, and in that the central part of the web portion (1) is formed with two U-shaped attachment rails with a common web portion (5) and opposingly directed shank pairs (7,8 and 9,10) which together with the attachment web portion (5) define similar channels, in which building members and/or clamping elements of the constructional member are insertable.2. A member as claimed in claim 1, characterized in that the base rail, with the exception of the engaging latching members coacting with one of the leg portions, is formed substantially mirror symmetrical about a symmetry plan in the longitudinal direction of the rail.3. A member as claimed in claim 1, characterized in that the releasingly attachable leg portion (3) on its outer surface facing away from the other leg portion is provided with means for locking or pivoting engagement with the rai-i . A member as claimed in claim 1, characterized in that a fastening element associated with the constructional member consists of a clamping rail (Fig. 3), which is U-shaped in cross section and provided with a web portion ( and two shanks, the height of which from the outer surface of the web portion facing away from the shanks substantially corresponds to the height of the supporting limbs (k) of the base web portion (1) and that the web portion of the clamping rail is also formed with two gripping 'elements (12) which are at the ends provided with hooks and intended for engagement with the shank ends (7,8 and 9,10) of the attachment rails.5. A member as claimed in claim k , characterized in that the U-shaped clamping rail (Fig. 3) is mirror symmetrical about a symmetry plane in the length of the rail and through the centre -of the web portion (11). 6. A member as claimed in either of claims k and 5, characterized in that the clamping rail (Fig. 3) is so adapted in width that in its fixation in any of the attachment rails (5,7,8 or 5,9,10) gaps a re formed between the shanks of the clamping rail and opposing portions of the base rail, said portions either consisting of the supporting limbs (h) or the leg portions (2,3), where¬ by building elements of different kinds are fixable by clamping action in said gaps, and that the width of the clamping rail is adjustable to the building details intended for fixing in the gaps. STATEMENTUNDERARTICLE19From the cited references quoted both during examination of the national as well as the international application it is clearly apparent that up to now a constructional member has been completely lacking, having such universal use as is the case with the member according .to the invention. The main reference in the national application is the publication CH-PS 584 338 which relates to a metal frame structure for glazed windows and doors where, to meet all the assembly needs, at least five different sections must be used for these applica¬ tions alone. Every one of these sections is furthermore exceptionally complicate and the cost thereof is also extremely high.The two ci ed references FR-PS 2 107 391 and 2 100 177 also show a plurality of sections, the use of which has so far been compulsory for meeting different installation needs. Reference is especially made to the former of the French patent specϊ fcations where Figs. 1-15 show different sections which must be combined in different ways for-the instal lations in question.The references FR-PS 2 200 28, 2 281 482 and 2 172 307 and DT-PS 969 7 9, cited in the international application, are not closer to the inventive subject than the patent specifications discussed above.In Fig. 2 in FR-PS 2 172 307 there is indeed shown a symmetrical U-shaped rail, but it does not have any removable limb and is more reminiscent of the clamping rail according to the present invention, although the rail according to Fig. 2 in the reference is not used together with any base rail, and the technical effect of the combination of clamping rail and base rail according to my invention is not anticipated in any way by this reference.Constructional members according to the present invention can be used in the field of building technology for practically all types of interior decoratio fittings and for window and door frames in a number of different applications illustrated by the drawings. In all the applications a base rail according to the invention is thus incorporated either separately or together with a clamping rail according to the disclosures in the claims now filed. In all the embodiments the base rail with'its removable leg thus constitutes a universal constructionalBUREΛ _ OΛ.PI s b. WIPO κ* . member which, either by itself or together with the clamping rail, can be used in building up different structural details and those for interior decoration fittings. The construction of the base rail is characterized by the shape of its leg portions and web portion, and it forms four U-shaped channels, defined by the main claim now filed, and enabling i s adaptation to a plurality of different fields of use and also enabling joining together several basic rails to form beams, as exemplified by Figs. 15 and 16. Since the clamping rail width can be suited to the building details intended to be fixed between the shanks of the clamping rail and the legs of the base rail, this combination can be used in a plurality of applications, as is apparent ϊ.a. from Figs. 6 and 8-14. | KARLSSON J | KARLSSON J |
WO-1979000064-A1 | 1,979,000,064 | WO | A1 | XX | 19,790,222 | 1,979 | 20,090,507 | new | B65D31 | B31B49 | B65D30, B65D33 | B65D 33/18 | SEALABLE LONGITUDINAL SLEEVELESS VALVE BAG | A bag of tubular form closed at one end and partially closed at the other end by a first rear wall portion (58) being folded over and sealed to a front wall (34, 35). The opening between a second rear wall portion (59) and opposed front wall (34, 35) forms the valve which is sealed after filling by folding the longitudinally extending second rear wall portion (59) over and sealing it to the opposed front wall (34, 35) using the folded first rear wall portion (58) as a reference. Adjacent lateral termination of the plural ply rear wall portions are oppositely stepped so as to overlap when sealed to the front wall (34, 35). | DescriptionSEALABLE LONGITUDINAL SLEEVELESS VALVE BAG Technical FieldThe present invention relates generally to sealed bags and more specifically to a sleeveless valve bag or partially closed open mouthed bag. Background Art Currently, there are two basic types of bags being used in the industrial packaging field; namely, the valve bag and the open-mouth bag. A serious limitation of the valve bag is the inability to achieve a positive closure to prevent leakage and sifting of the product from the. bag, to prevent insect in estation and • to obtain a hermetieal seal. To improve the closure of the seal, the valve opening may be made smaller, but this reduces the filling speed. Thus the designer of valve bags must weigh the positive closure of the valve against the filling speed. A typical valve bag 15 of prior art is illustrated in Figure 1 having a valve sleeve 16 extending between the interior of the bag and the exterior. The axis of the valve sleeve 16 is on the side of the bag or along the lateral axis. The lateral valve bags may be filled -horizontally as is the case in the United States, or vertically as is the case of some foreign countries. Either method of filling a lateral valve bag does not make effective use of the volume of the bag because of the angular repose of the product filling the bag.Thus there is existing need for a valve bag with an opening large enough to insure maximum filling speed, located to make ef ective use of the filling rate and bag volume and capable of easily and conveniently being hermetically sealed.The open mouth bags are either tube style or pinch style wherein the latter provides a better seal. The pinch style, open mouth bag is a gussetted open mouth bag that has a specific type of closure. This closure can, when properly made, provide a hermetieal seal. A serious limitation of this specific open mouth bag is that the entire tope of the bag is open and after the filling operation is completed, the bag top must be reformed and flattened for entry into a closing and sealing machine. A typical example of prior art open mouth bags in the open and sealed condition are illustrated in Figures 2 and 3 respectively. Due to the nature of the bag construction, the bag top must be level when entered into the closing machine, within a narrow angular tolerence, to insure that the closing operation along the complete bag top width is accomplished properly and the hermetieal seal actually obtained. In addition to the level requirement, there must be a wrinkle and warp free bag top surface in the closure to assure a heremetical seal. Since the complete bag top must be reformed and flatteπied a since the bag tends to be rounded from the material contained, warp-age a wrinkles can easily be generated during the reforming operation. To minimize t condition, the level of material, in relation to the bag top edge (known freeboard), must be low (approximately 9 inches from the top of the bag) to ins a quick, easy and reliable closure and seal. This relationship between the fill li and fold line' is illustrated in Figure 4. Clamps are also schematically shown, whi hold the gussets formed at the top edge and maintains the top edge horizontally assure a completely sealed closure. As can be seen, the devices of the prior art 0 Order to assure a perfect seal, drastically reduce the fill opening.Thus there exists a need for a tube or pinch style, open mouth bag havin large fill opening for a given linear length of top edge, a wide tolerance or bag t level condition for closing and sealing, and reducing the amount of freeboard a consequently paper needed to effect a sealed closure for a given volume of produDisclosure of InventionThe bag of the present invention is a longitudinal, sleeveless valve b formed from a tubular construction of flexible sheet material. The tube is clos at a first or bottom end by folding one wall back over the opposed wall and seali 0 i thereto. The second or top end is partially sealed by having a first rear w portion folded over a lateral axis and sealed to an opposed front wall portion. second rear wall portion extends longitudinally beyond the longitudinal terminati of the front wall portion to form the sleeveless valve with the opposed front w portion. The tube is longitudinally creased so as to form the front and rear walls a tube or reverse creased to form front and rear walls with a pair of gusse deposed therebetween. The gusset between the rear wall portion and opposed fro wall portion has stepped longitudinal termination between the longitudin termination of the front and rear walls. The gusset eontinguous to the second re wall portion forms a part of the longitudinal sleeveless valve. The first and second rear wall portions are ormed in a single ply bag by n sealing the longitudinal seam completely and in a plurale ply bag by t longitudinal cuts. The first longitudinal cut severs the outer ply of the rear wa and second longitudinal cut, which is displaced laterally from the first longitudin cut and is at the edge of the valve opening, severs the interior ply of the rear w portion. The two longitudinal cuts provide an outer ply of the second rear w• portion which extends laterally across the sealed portion so as to overlap the seal portion when the second rear wall portion is folded over and sealed to its oppos-BUO front wall portion; thereby providing a more perfect seal of the valve. The two longitudinal rear wall cuts and a front wall cut, corresponding to the second rear wall cut, all extend down to the folding line which lies along the lateral axis previously described. The pre-sealed irst rear wall portion provides a reference to the lateral axis such that the second rear wall portion may be folded along this lateral axis., .The bag construction of the present invention provides a bridge between the valve and open mouth bags of the prior art usable in both types of filling operation with improved results. The bag of the present invention provides a valve which is sleeveless and can be heremetieally sealed, automatically, and at any speed of production considerably in excess of a conventional valve bagging operation.By using a longitudinal valve, the sealing technique of plastic lined, open mouth bags can be used to provide a here etical seal. The use of the gusset to increase and standardize the valve opening is also possible while increasing the filling speed over conventional valve bags. This construction also simplifies the bag manufacturing operations and bag filling and sealing equipment.Due to the construction and location of the opening in the new bag, the new bag can be filled with greater degree of weight accuracy of both granular free flowing materials and fine powders.Due to the construction and location of the opening in the new bag and the pre-sealing of most of the bag top, less paper is used in the construction of the bag for a given volume of material to be contained in comparison to conventional valve bags. The efficiency of utilizing the available bag volume is enhanced by eliminating the sleeve, orientation of the fill opening to the longitudinal axis of the bag and method of closure.Due to the small linear dimension (in the flat folded condition) of the opening and its location at the top of the new bag for filling, compared to the side opening as in prior art valve bags, the reforming of the one gusset and folding of this short length of opening top for sealing is easily and readily accomplished with greatly increased reliability of a leakproof and siftproof and air tight seal.Due to the construction of the bag opening and the location of the opening in relation to the longitudinal axis of the bag, the new bag lends itself readily to a fully automatic bag placing, opening, filling and sealing system that can be made available economically for speeds of 12 or less bags per minute or avialable to operate at speeds up to 50 bags per minute. Compared to the open mouth bags, the bag of the present invention will fi under certain conditions, at the same rate. As a result of the new bag constructi it is possible to achieve a fully, automatic closure with greatly increased reliabili at speeds much higher than existing fully automatic pinch style systems wi equipment that is considerably less complicated.Due to the pre-sealing along most of the bag top width and the method filling, the present bag reduces the freeboard need to eliminate buckling of t front and rear walls and reform the gussets as filled before sealing and there reduces the amount of paper needed to package a given volume of product. Since the bottom and most of the top of the bag of the present invention pre-sealed and the ill opening comprises a small portion of the front and rear w width, the opening is readily and positively sealed without misalignment.Other objects, advantages, and novel features of the present invention w become apparent from the following detailed description of the invention wh considered in conjunction with the accompanying drawings.Brief Description of DrawingsFigure 1 is a perspective view of a lateral valve bag of the prior art.Figure 2 is a perspective view of an open mouth bag of the prior art in t open condition.Figure 3 is a perspective view of an open mouth bag of the prior art in t sealed condition.Figure 4 is a perspective view of an open mouth bag of the prior art bei held during filling. Figures 5, 6 and 7 are views of the process of forming a gussetted, plural p bag into a tube with a sealed bottom according to the prior art.Figure 8 is a perspective view of the gussetted bag of figures 5, 6 and modified according to the present invention.Figure 9 is a perspective view of a sleeveless valve bag embodying t principles of the present invention and formed from the gussetted bag of figure 8.Figure 10 is a perspective view of a sleeveless valve bag of the prese invention being held during filling.Figure 11 is a perspective view of a laterally interior sleeveless valve b embodying the principles of the present invention. Figure 12 is a perspective view of plural ply bag with a plastic lini embodying the principles of the present invention.-BOO Figure 13 is a perspective view of a single ply, gussetted bag modified according to the present invention.Figure 14 is a perspective view of a sleeveless valve bag formed from the gussetted bag of Figure 13. Figure 15 is a perspective view of a sleeveless valve bag formed from a tube style, open mouth bag embodying the principles of the present invention.Figure 15 is a perspective view of a sleeveless valve bag embodying the principles of the present invention.Figure 16 is a perspective view of a sleeveless valve bag embodying the principles of the present invention.Figure 17 is a perspective view of a bag having a pair of sleeveless valves embodying the principles of the present invention.Best Mode for Carrying out the Invention Figure 5 illustrates a blank of the prior art from which a gussetted bag is formed having two plies 20 and 21 of flexible material, such as kraft or other type paper glued together at 22 and 23. The lateral edges 24 and 25 of ply 20 are stepped relative to the lateral edges 26 and 27 of ply 21 so as to overlap and form a smooth longitudinally sealed tube as will be explained. The blank is longitudinally creased at 28, 29, 30, 31, 32, 33 to form front panels 34 and 35, rear panel 36 and gusset panels 37, 38, 39, 40. The top longitudinal edge 41 of the blank is stepped down from rear panel 36 to the front panels 34 and 35. The opposite or bottom longitudinal edge 42 is stepped down in the reverse order between rear panel 36 and front panels 34 and 35. Gusset panels 37, 38 and 39, 40 are reversely folded alon - longitudinal creases 29, 30 and 31, 32 as illustrated in Figure 6. Front panels 34 and 35 are reverse folded about longitudinal creases 28 and 33 respectively so that the lateral edges of the blank are bonded together by adhesive strips 43 and 44 when the lateral edges 25 and 26 of the blank overlapped. This longitudinal seal is illustrated in Figure 7 and 8 Four strips of adhesive materials 45, 46, 47 and 48 are applied to the bottom edge of the blank illustrated in Figure 7 and the front wall panels 34 and 35 are folded along fold line 49 to bring the front wall panels 34 and 35 and the step end of gusset panels 37, 38, 39 and 40 adjacent the rear panel 36 to be sealed at 50. The process so far deseribed in Figures 5, 6 and 7 to form a tubular shaped bag having longitudinal creases to form a front and rear panel having gusset panels disposed there-between and being sealed at one end are well known and considered part of the prior art as exemplified by U.S. Patent 4,008,850. As also is well kno in the prior art four adhesive strips 52, 53, 54 and 55 are applied to the top edges illustrated in Figure 8.The bag of the prior art being of tubular shape having a sealed bottom a adhesive areas on . the open top edge is modified according to principles of t present invention to provide a sleeveless valve bag. The exterior ply 21 of re panel 36 is cut along longitudinal line 57 and interior ply 20 of rear panel 36 is c along longitudinal axis 56 dividing the rear panel 36 into first rear panel portion 5 and second rear panel portion 59. The front panel 35 is also cut through both pli along longitudinal line 56. The length of the longitudinal cut along axis 56 and 5 are from the top edge of the front and rear panels down to the fold line 60 in th front and rear panels. The first rear panel portion -58 is folded along fold line 6 and sealed to the front panels 34 and 35 at 61 using adhesive strips 52, 53, 54, an 55 as shown in Figure 9. Additional adhesive is added to extend strips 52, 53, 54, 5 to the inner surface of exterior ply 21 of rear wall portions 59.As can be seen in Figure 9, the exterior ply 21 of rear wall portion 5 extends laterally across the sealed first rear wall portion 58. The extension exterior ply 21 of rear wall portion 59 beyond interior ply 20 is equal to th extension of interior ply 20 of rear wall portion 58 beyond the termination exterior ply 21 of portion 58. The importance of the equality of the extension the two lateral portions is such that when the second rear wall portion 59 is folde along fold line 60 when the bag is filled and sealed to the front wall panel 35, th exterior ply 21 of rear wall portion 59 is adjacent to exterior ply 21 of rear wa portion 58 to form a continuous surface thereby avoiding an edge which may b caught and thereby damage the exterior ply and seal. The main purpose of eve forming exterior ply 21 of rear wall portion 59 extending laterally past th termination of interior ply 20 is to cover and seal the inside edge or point 62 of th open portion of the valve and thereby prevent a pinpoint leak through the finall sealed top. For certain materials, the pinpoint opening 62 is not critical. For thes materials, a single cut 56 is sufficient. Similarly, a single cut 56 could be used an a separate patch is added to the second rear wall portion 59 to function as th extended exterior ply to cover edge 62.The bag illustrated in Figure 9 embodies a pinch type tubular bag bein sealed at one end and partially sealed at the other end so as to have a longitudin sleeveless valve formed between rear wall portion 59 and opposed front wall pan 35 and includes the gusset panels 39 and 40. The sleeveless valve after filling is capable of being sealed by folded along the lateral fold line 60 which is reference to the pre-folded rear wall section 58. The valve is capable of being sealed so as to be leak and sift proof and to prevent insect infestation. The advantage of the bag of Figure 9 is illustrated in Figure 10 wherein the gussetted panels 39 and 40 are open to increase the size of the valve without occupying a major portion or width of the front and rear panels. The pre-sealed rear wall portion 58 consitutes a substantial portion or greater than a majority of the width of the bag. Preferably the section 58 constitutes at least 75 percent of the width. This percentage is based on a preferred fill diameter of 3 3/4 inches of bags having widths of 15 to 17 inches with gussets of 3 to 5 inches requiring a linear lateral length of 4 to 4 1/4 inches of the front or rear panels. The importance of the pre-sealed section is that top edge 63 provides a reference of the fold line 60 which is displaced from the top edge 63 by the thickness of the plies. The bag may be filled at any angle since a lateral reference 63 is provided for the forming of the seal for the second rear portion 59. Similarly, by having section 58 constitute a substantial portion of the top, buckling, wrinkles and other problems of open mouth bags are reduced since a majority of the seal is formed prior to filling.A comparison between Figures 4 and 10 will illustrate that the fill line of Figure 10 is far higher than the fill line of Figure 4 therefore allowing greater use of the capacity of the bag. The ability to fill higher in Figure 10 versus Figure 4 is because the edge 63 of pre-folded top section 58 provides a reference of the lateral axis 60 and it reduces reforming problem and consequently the holding of the bag by the clamps during filling and at the sealing station may be placed at the top of the bag thereby reducing the freeboard.In the preferred embodiment, the second rear portion 59 is contiguous a gussetted side to provide maximum fill opening, per. linear lateral dimension of the face panels by using the gusset. Alternatively, the longitudinal sleeveless valve may be spaced from the side panels as illustrated in Figure 11. Two sealed rear portion 64 define a valve having a third rear portion 65. Not only does the embodiment of Figure 11 not make efficient use of the available bag material but doubles the cuts needed to seal the edge of the valve.If reduction of wrinkle or warp top surfaces are not a concern, the sealed or first rear portion 58 may be a very small portion of the top width and the second- t REA (TO PI rear portion 59 a substantial portion. The only limitation on the width of portion is that it be long enough to provide a reference edge 63 for fold axis 60 preferably an area to be clamped during filing.Although the modification of the tube shaped bag of the prior art has b described having cuts 56 and 57 made after the formation of the tube formed figures 5 through 7, the cuts of the front panel 35 and rear panel 36 may be m during the cuts needed to form the blank in figure 5. The rear panel's exterior 21 is cut along line 57 and interior ply 22 is cut along line 56. The front panel 35 cut along a line which will coincide with line 56 when folded into a tube. Also, adhesive strips including the extension onto the inner surface of exterior ply 21 m all be forward at the same time or process step.The sleeveless valve bag of the present invention may have the capability forming a hermetieal seal as illustrated in Figure 12 by being formed from a thr piy tubular bag. The outer ply 70 and middle ply 71 are of kraft or other types paper and the inner ply 72 is a plastic for example, polyethelene. The bottom front wall 73 is sealed to rear wall 74 at 75 by heat sealing and adhesive. Adhesi strips 76 are provided on the top edge, as is well known in the prior art. At le the inner ply 72 of rear wall 74 is cut along longitudinal. axis 77 and at least t outer ply 70 of rear wall 74 is cut along longitudinal axis 78. The middle ply 71 m be cut along axis 77 or 78 or in the alternative may be cut along a third longitudi axis between axis 77 and 78. The cuts along axis 77 and 78 divide the rear wall into rear wall portions 80 and 81. The first rear wall portion 80 is heat sealed alo heat seal line 82, then it is folded along fold line 83 and sealed by adhesive 76 the front wall 73. This provides the partially sealed top having a reference alo lateral fold axis 83 and produces the sleeveless valve comprising rear wall porti 81 and opposed front wall portion 73. After filling through through the valve it heat sealed along axis 82 and then folded along lateral axis 83 and bound adhesive 76 to the front wall 73. The operation and funeion of the elements Figure 11 are identical to those described in Figures 8 and 9 with the improv results of forming an hermetieal seal because of the polyethelene or plastic lin interior ply 72. It should be noted that in lieu of a plastic liner 72, an interi paper ply may be used and it may be coated with a plastic. As is well known in t prior art the heat seal 82 which binds the front and rear panels of interior ply together is longitudinally above the fold line 83 and therefore is protected by t fold and seal thereof.•^U O The sleeveless valve of the present invention can be formed in a single ply tube. As illustrated in figures 13 and 14, a single ply 90 is creased longitudinally and folded to form front panel 91, side gussets 92 and 93, and rear panels 94 and 95. The rear panels overlap and are sealed along the length of the bag except for the height above the top edge 96 of the front panel 91. This provides the two rear wall portion extending beyond the front wall termination 96 which overlaps without cutting. The rear panel 94 is folded along top edge 96 over the front panel 91 and sealed thereto at 97 by adhesive strips 98 (only one of which is shown). It should be noted that by not cutting or folding the front' panel 91 a good seal is formed, but not as good as the seal of figure 9. If desired, the bags of figures 9 and 12 may not include a cut in the front panels and the fold line be the top edge of the front panel. Similarly, the front panel in figure 14 may be cut and the fold line may be below the top edge 96.A non-gusset tube bag is illustrated in figure 15 as including a front panel 100 separated from a rear panel by two longitudinal creases 102 and 103. The bag is two ply having the rear panel 101 cut along lines 104 and 105 to form two rear portions 106 and 107 having overlapping ply elements. Front panel 100 is also cut along line 105. Rear portion 107 is folded about fold line 108 and sealed to front panel 100 at 109. A longitudinal sleeveless valve is ormed by rear portion 106 and opposed front panel. The seal produced for a non-gussetted tube bag is sufficient for some uses, but is not considered as good as the seal for stepped gussetted bags of figures 9 and 12. The bag of figure 15 does not have the advantage of the gusset to increase the valve opening. Similarly, Figure 15 illustrates that the valve rear panel portion 106 may constitute a larger percentage of the bag width than the seal rear panel portion 107 if so desired, though not preferred.Another embodiment of the longitudinal sleeveless valve is illustrated in figure 16 wherein the front wall panel 110 and gussets 111 are the same longitudinal length as the rear panel 112. The seal produced in this embodiment is not considered as good as those where the front panel and gussets are stepped relative to the rear panel as in figure 8.A pair of sleeveless valves may also be provided as illustrated in figure 17. A first rear wall portion 115 is sealed to the front wall 116 and a pair of second rear wall portions 117 and 118 extend beyond the seal portion forming a pair of sleeveless valves with respective gussets 119 and 120. The second rear wall portions each have a lateral extension, preferably an outer ply which extend across the sealed rear wall portion 315.-BU E ΓOMPI The versatility of the sleeveless valve is illustrated by the variance placement of figure 11 and the variance of number of figure 17. Similarly, the sty of bag and the location of the fold line may also be varied as illustrated, dependi upon the type of seal desired. From the preceding description of the preferred embodiment, the objects the invention are attained in that a sleeveless valve bag having a longitudinal filli valve is provided which is capable of being sealed without misalignment to provi a leak proof, sift proof, and insect infestation proof bag. Although the inventi has been described and illustrated in detail, it is to be clearly understood that t same is by way of illustration and example only and is not to be taken by way limitation. The bags have been described as being made of paper, but the inventi may be practiced with plastic bags whether tube or gussetted. The spirit and sco of this invention is to be limited only by the terms of the appended claims.-BUO | Claims1. A bag having a sleeveless longitudinal filling valve, formed from a single blank, a tube closed at one end, and longitudinal creases forming front and rear walls, characterized by a first rear wall portion of said blank unitary to said tube being folded along a lateral axis and sealed to said front wall for providing a reference of said lateral axis, and a second rear wall portion of said blank unitary to said tube extending longitudinally beyond said lateral axis for forming with opposed front wall portion said longitudinal valve, said longitudinal valve being closable by folding said second rear wall portion along said lateral axis and sealing said second rear wall portion to said opposed front wall portion to provide a leak and sift proof and insect impervious bag.2. The bag according to claim 1 wherein second rear wall portion extends laterally from a longitudinal edge of said rear wall.3. The bag according to claim 2 including longitudinal creases forming a pair of gussets deposed between said front and rear walls, the gusset contiguous said second rear wall portion forming part of said longitudinal valve.4. The bag according to claim 2 wherein said second rear wall portion includes a lateral portion extending across a portion of said first rear wall portion.5. The bag according to claim 2 wherein said bag is single ply sealed along a longitudinal seam formed by two superimposed sections, said first and second rear wall portions are non-sealed extensions of said superimposed sections.6. The bag according to claim 1 wherein said first rear wall portion includes two sections, each extending laterally from opposite longitudinal edges of said rear wall toward said second rear wall portion.7. The bag according to claim 6 wherein said second rear wall portion includes lateral portions each extending across a portion of a respective section of said irst rear wall portion. 8. The bag according to claim 1 wherein said bag includes at least two plies of flexible sheet material, the outer ply of said second rear wall portion extends laterally beyond the termination of the inner ply of said first rear wall portion.9. The bag according to claim 1 wherein said bag includes at least two plies of flexible material, the outer ply and inner ply of said rear wall are severed along spaced longitudinal axes to form said first and second rear wall portions having adjacent stepped lateral terminations.10. The bag according to claim 9 wherein the outer ply of said second rear wall portion extends laterally beyond the termination of the inner ply of said first rear wall portion.11. The bag according to claim 1 wherein said second rear wall portion includes two sections, each extending laterally from opposite lateral edges of said rear wall toward said first rear wall portion.12. The bag according to claim 11 wherein each of said sections includes lateral projections extending across a respective portion of said first rear wall portion.13. A bag of tubular form closed at one end and partially closed at the other end, comprising longitudinal, reversed creases along portions of said bag providing at least one gusset between front and rear wall portions, a first rear wall portion being sealed to said front wall portion forming the closed portion of said other end, a second rear wall portion extending upwardly at the open portion of said other end, said gusset extending upwardly at said open portion beyond said front wall portion and terminating below the termination of said second rear wall portion, said second rear wall portion and opposed front wall portion and said gusset forming a sealable sleeveless longitudinal filling valve.14. The bag according to claim 13 wherein said opposed front wall portion extends upwardly beyond said closed portion and terminates below the termination of said gusset.-BUO 15. The bag according to claim 14 wherein said gusset includes two panels, the panel contiguous said opposed front wall portion terminates below the termination of the panel contiguous said second rear wall portion whereby said valve is capable of forming a leak proof, sift proof and insect impervious seal.16. The bag according to claim 13 wherein said bag includes at least two plies of flexible sheet material, the outer ply of said first rear wall portion terminates laterally before the termination of the inner ply of said first rear wall portion and said inner ply of said second rear wall portion terminates laterally before the termination of the outer ply of said second rear wall portion.17. The bag according to claim 16 wherein the lateral termination of said outer ply of said first and second rear wall portions and the inner ply of said first and second rear wall portion are respectively aligned longitudinally.18. The bag according to claim 13 wherein said bag includes at least two plies of flexible sheet material, the outer ply of said second rear wall portion extends laterally beyond the termination of the inner ply of said first rear wall portion. . . - .19. The bag according to claim 13 wherein said first rear wall portion is sealed along at least 51 percent of the width of said front wall portion.20. A sleeveless valve bag comprising a tube closed at one end, longitudinal creases forming front and rear walls on said tube, a first rear wall portion being sealed to said front wall at the other end, a second rear wall portion extending longitudinally beyond said front wall at said other end forming a longitudinal valve between said second rear wall portion and opposed front wall portion; said opposed front wall portion extends longitudinally beyond the top of said seal and terminates below the termination of said second rear wall portion.21. The sleeveless valve bag according to claim 20 wherein said first rear wall portion and a portion of the top of opposed front wall are folded over said front wall and sealed thereto. 22. The sleeveless valve bag according to claim 20 wherein said first rear wall portion is folded over the top edge of said front wall and sealed thereto.23. The sleeveless valve bag according to claim 20 wherein said second rear wall portion extends laterally across a portion of said first rear wall portion.24. A sleeveless valve bag comprising a tube closed at one end, longitudinal creases forming front and rear walls on said tube, a first rear wall portion being sealed to said front wall at the other end, a second rear wall portion extending longitudinally beyond said front wall at said other end forming a longitudinal valve between said second rear wall portion and opposed front wall portion, and said tube includes at least two contiguous plies of flexible sheet material, the outer ply of said second rear wall portion extends laterally beyond the termination of the inner ply of said second rear wall portion.25 The sleeveless valve bag according to claim 24 wherein the termination of said outer ply of said first and second rear wall portions and the termination of said inner ply are respectively of said first and second rear wall portions aligned longitudinally.26. The method of fabricating a tube bag including cutting a unitary blank and forming the tube from a plurality of plies of flexible material and sealing one end of the tube, the improvement comprising longitudinally cutting the rear wall of said tube, which extends beyond the front wall at the other end of the tube, from at least the longitudinal termination of said rear wall to the longitudinal termination of said front wall to divide said rear wall into a first and second rear wall portions, folding said first rear wall portion over said front wall and sealing said first rear wall portion to said front wall while maintaining said second rear wall portion in an unfolded condition to form a sleeveless valve at the opening between the front wall and said second rear wall portion.27. The method according to claim 26 including longitudinally cutting said front wall the length of a portion of the front wall which is to be folded over when said first rear wall portion is sealed to said front wall, said cutting of said rear wall extends past the longitudinal termination of said front wall equal to said length and folding said first rear wall portion and adjacent front wall over said front wall.28. The method according to claim 26 wherein said longitudinal cutting is performed before forming said tube.29. The method according to claim 26 wherein said longitudinal cutting is performed after forming said tube.30. The method according to claim 26 wherein said longitudinal cutting includes cutting the outer ply and the inner ply of said rear wall along spaced longitudes.31. The method according to claim 30 wherein the longitudinal cutting of the outer ply is spaced from the lateral edge of the seal of said first rear wall portion forming a portion of the outer ply of said second rear wall portion which extends laterally beyond said lateral edge of said seal.32. The method according to claim 26 wherein said sealing includes folding said first rear wall portion along a lateral axis providing a reference for folding said second rear wall portion. | RUNO W | RUNO W |
WO-1979000069-A1 | 1,979,000,069 | WO | A1 | EN | 19,790,222 | 1,979 | 20,090,507 | new | C02B1 | F24J3 | B01D1, C02F1, F24J2 | C02F 1/14, F24J 2/20B, F24J 2/20E | APPARATUS FOR SIMULTANEOUS RECOVERY OF FRESH WATER AND SALT OR CONCENTRATED SALINE SOLUTION | Apparatus for simultaneously recovering fresh water and salt or concentrated saline solution by direct collection of solar energy through special energy elements. Each energy element consists of two substantially horizontally arranged foils (10, 20), which in longitudinal direction of the elements are jointed in several places in the transverse direction, so that each element includes a plurality of longitudinal gaps (11, 12, 13, 14) for sea water transport. Each of the energy elements is attached mechanically at one end to an inlet (18) for sea water and at its remaining end (17) attached mechanically to an inlet on an evaporation chamber for the recovery of fresh water in known manner. By the invention large surfaces for solar radiation are obtained with little material consumption, thereby rendering the elements cheaper than conventional elements. The foils (10, 20) preferably are made of a black plastic material, which implies high energy absorption capacity, low weight and absence of corrosion problems. | Apparatus for simultaneous recovery of fresh water and salt or concentrated saline solutionThis invention relates to an apparatus for recovering simultaneously fresh water and salt or saline solution by direct collection of solar energy by means of special energy elements.The invention has the object to bring about an apparatus, which yields higher returns at a lower price compared with conventional apparatuses operated with oil, electricity or the like. The charact- erizing features of an apparatus according to the invention become apparent from the attached claims.The invention is described in greater detail in the following, with reference to the accompanying drawings, in whichFig. 1 is a front view of a flow element comprised in an apparatus according to the invention,Fig. 2 is a lateral view of the flow element,Fig. 3 is a front view of a clamping element comprised in the flow element, Fig. 4 is a lateral view of the clamping element, Fig. 5 shows an inlet (or outlet) in the flow element with a laid-in clamping element, and Fig. 6 shows an apparatus comprising several flow elements accord¬ ing to Figs . 1 -2.The flow element according to Figs . 1 -2 consists of two thin foils 10 and 20, which are jointed in longitudinal direction of the flow element by intermittent welding in several places in the transverse direction, so that the flow element includes a plurality of longitudinal gaps for water transport. In Fig. .1 three' such gaps are indicated to the left and one to the right, . their reference numerals being 11 , 12, 13, 14. The term intermittent welding is to be understood so that the welding joints are discontinuous . A welding joint is designated by 15, and a distance between two joints is designated by 16. It is pos sible in principle to weld continuous joints, but discontinuous joints give rise to a certain turbulence at the water flow. The flow element is connected at one end to two inlets 18 and at its other end to two outlets 17. Between the outlets 17 a clamping ele-OMPI ment 21 -22 is provided, the ends of which are secured in the inlets 18, and the foils 10, 20 are so laid about the clamping element, that the clamping element is located between the foils . The clamping ele ment appears more clearly from Figs . 3 -4. It has the form of a T with an arc -shaped roof 21 and a straight remaining portion 22. The manner in which the clamping element is secured in an outlet 17 and, respectively, inlet 18 appears more clearly from Fig. 5, which sho an outlet 17 from the si-de with two proj ections 171 and, re spectively 172 on the inside of the outlet. The end of the remaining straight po tion 22 is pres sed in between said proj e ctions 171 and 172.The flow element is connected in the same manner to the two inlets 18, and the foils 10, 20 are laid about a clamping element identical with the element 21 -22. The flow element may have a width of about 4 m and a length of 10 m, the distance between a welding joint and th nearest adjacent joint may be 3 to 4 cm, and the diameter of a flow gap at a system filled with water may be 2 to 3 cm.An apparatus according to the invention comprises a great number of flow elements of the kind described above. Said flow elements con¬ stitute special energy elements for direct absorption of s olar energy Each of these energy elements is at one end attached mechanically to inlets for sea water and at its remaining end attached mechanically to inlets on an evaporation chamber for recovery of fresh water in known manner .In the apparatus according to Fig. 6 the ener gy elements are divided into several units . A first one of said units compris e s a plurality of energy elements 61 1 , 612, 6ln connected in parallel, which elements are coupled mechanically on the inlet side to an inlet 613 for surface water from the s ea and on the outlet side are coupled mechanically t an inlet 614 on a first evaporation chamber 615. An outlet 616 on said fir st evaporation chamber 615 is coupled mechanically to an inle 623 on a second unit of said units , which unit consists of a plurality energy elements 621 , 622, 62n connected in parallel. Said unit is coupled mechanically on the outlet side to an inlet 624 on a second evaporation chamber 625. About twenty units with ener gy elements are coupled mechanically in the manner des cribed to about twenty evaporation chamber s, so that a last evaporation chamber 63n on the inlet side 634 is coupled to a last unit of said units, and on the outlet side 636 is coupled to a conventional salt-works 637 for evaporation of the residual water amount in the water pumped up from the sea.The evaporation chambers are designed in a manner known per se, for example according to SE-PS 387 927, comprising a first plurality of plane parallel and vertically arranged plates poured on with relative¬ ly warm sea water, and .a second plurality of plane parallel and vertically arranged plates poured on with relatively cold fresh water, • and coolers designated in Fig. 6 by 618, 628, 638. The water fed in to an evaporation chamber from a unit with energy elements has a temperature of about 70 C, and the water discharged from the evaporation chamber has a temperature of, for example, about 30 C or lower. At a temperature difference of about 40 C bet¬ ween the plates in the evaporation chamber, and at 25 evaporation chambers connected in series according to Fig. 6, 850 litre per 1000 litre sea water fed in pass over to the fresh water side. This implies that the salt content on the outlet side 636 of the last evaporation chamber amounts to about 23 %. The remaining water amount evaporates in the salt-works 637. The material in the energy elements preferably is black plastic mate¬ rial, which is covered by a foil of transparent plastic material in order to reduce convection losses between energy elements and ambient air . It is to be pointed out in this connection, that the in¬ formation in the above des cription and the attached claims that the flow elements consist of two foils, is to be understood so that two defining walls of the flow elements consist of foils . Thus, in principle nothing obstructs each foil wall to consist of several partial foils. | Claims1. An apparatus for simultaneously recovering fresh water and sa or concentrated saline solution by direct collection of solar energy through special energy elements, characterized in that said energy elements each comprises two substantially horizontally arranged foils, which are jointed in longitudinal direction of the ele¬ ments, for example by intermittent welding, in several places in the transverse direction, so that each energy element includes a pluralit of longitudinal gaps for transport of sea water, each of said energy elements at one end attached mechanically to inlets for sea water and at its remaining end attached mechanically to inlets on an evaporatio chamber for recovering fresh water in known manner.2. An apparatus according to claim 1, characterized in tha said energy elements are divided into a plurality of units, that a first unit of said units comprises a plurality of energy elements connected in parallel, which on the inlet side are coupled mechanically to an inlet for surface water from the sea and on the outlet side are couple mechanically to an inlet on a first evaporation chamber, that an outle on the first evaporation chamber is coupled mechanically to an inlet on a second unit of said units, that an outlet on said second unit is coupled mechanically to an inlet on a second evaporation chamber, a. s. o. , and that an outlet on the last unit of said units is coupled mechanically to an inlet on a last evaporation chamber, the outlet of . which is coupled mechanically to a conventional water-works for evaporating the residual amount of water in the water pumped up fro the sea.3. An apparatus according to claim 1 or 2, characterized in that the material in said energy elements consists of black plastic material, and said energy elements are covered by a foil of trans¬ parent plastic material in order to reduce convection losses between energy elements and ambient air.TJU | ELMQVIST O | ELMQVIST O |
WO-1979000071-A1 | 1,979,000,071 | WO | A1 | XX | 19,790,222 | 1,979 | 20,090,507 | new | C08G63 | null | C08G63 | C08G 63/682D, C08G 63/81 | SOLUTION POLYMERIZED HALOGENATED POLYESTERS | A process for preparing certain halogenated aromatic polyesters having a predetermined molecular weight is provided. Such polyesters are prepared by solution polymerization of an appropriate bisphenol and diacid halide wherein the diacid halide is added to a solution containing the bisphenol until the viscosity of the resulting polymer containing solution reaches a predetermined solution viscosity limit at which time the further addition of diacid halide is terminated. The solution limit is indicative of the attainment of said predetermined molecular weight. The identification of said solution viscosity limit is achieved by a feedback mechanism wherein the viscosity of the polymer containing solution is monitored or sensed during or after the addition of the diacid halide to the bisphenol containing solution. | SOLUTION'POLYMERIZED HALOGENATED AROMATIC POLYESTERSTECHNICAL FIELDThis invention relates to solution polymerization of a. halogenated aromatic polyester.Halogenated aromatic polyesters may be prepared by solution polymerization of a halogenated aromatic bisph- 5-' enol and a diacid halide.BACKGROUND ARTIn accordance with typical solution polymerization .procedures of the prior art, the reactants are present in a common solvent which also serves as a solvent for the polymer under the conditions of condensation. The bis--10. phenol and the diacid halide are dissolved in separate portions of the chosen solvent. A catalyst or acid acceptor is added and the solutions are combined with agitation. Control of the molecular weight of the resulting polymer has hereto-fore Deen achieved by utili-15. zing specific amounts of reactants in accordance with exact stoichiometric calculations. Once the required amount of reactants have been determined in this manner they are rapidly combined and allowed to polymerize until ' a maximum inherent viscosity is achieved. Although this20. method is capable of achieving a polymer having predet¬ ermined molecular weight such a procedure possesses many disadvantages when carried Ou on- a.commercial scale. For example, commercial starting materials are non-uniform and they vary from batch to batch. Moreover, the start-25. ing materials often contain impurities which, although not adversely affecting the resultant polymer, require correction in the above described calculations to account for their presence.. Thus, a non-uniform and impure starting material often leads to weighing errors which in30. turn give rise to deviations from the predetermined molecular weight in the final polymer product.Typical solution polymerization procedures for preparing polyesters are outlined in the U.S. Patent Nos. Nos. 3,234,167 and 3,309,334.DISCLOSURE OF THE INVENTION -5. It is therefore an object of the present invention t provide an improved and relatively inexpensive process fo the preparation of high molecular weight halogenated aromatic polyesters of the type disclosed herein. The process has the advantage that it enables one to produce10. the polymer with a predictable molecular weight range, reproducibly, and is readily controlled.According to one aspect of the present invention there is provided a means for preparing a halogenated aromatic polyester having a predetermined molecular weigh15. and of the following recurring structural formula:20. where X, which.may be the same or different, is chlorine or bromine, Y, which may be the same or different, is . hydrogen, chlorine or bromine, R and Rτ may be the same o different and represent lower alkyl groups, or hydrogen, or together constitute a cyclic hydrocarbon group, and n25, equals at least 10, by the solution polymerization of a halogenated bisphenol and a diacid halide selected from the group consisting of isophthaloyl chloride, terephth- aloyl chloride-,and mixtures thereof which comprises pro¬ viding a solution comprising an organic solvent, a halo¬30. genated aromatic bisphenol, and an acid acceptor, adding the said diacid halide to the said solution under con¬ ditions such that the said diacid halide reacts with the said halogenated aromatic bisphenol to form a polymer, sensing the viscosity of the solution con aining the 5. resulting polymer, and terminating the addition of the diacid halide in response .to the sensing of a predeter¬ mined solution viscosity limit as defined herein.In another form of the invention the said solution containing the halogenated aromatic bisphenol is sensed10. as said diacid halide is added thereto forming the polymer and thereby causing an increase in solution viscosity, and the addition of the diacid halide is controlled in response to the sensed solution viscosity as the sensed solution viscosity approaches a predetermined solution viscosity15. limit as defined herein, and the addition of the diacid halide is terminated in response to the sensing of the predetermined solution viscosity limit.The addition of diacid halide is preferably con¬ trolled by gradually reducing the amount of the diacid 20. halide, which is added to the solution containing the polymer, to zero as the sensed viscosity reaches the predetermined .solution viscosity limit.In another modification the said diacid halide is added to the solution of halogenated aromatic bisphenol25. in an amount less than the amount necessary to achieve stoichiometric equivalence with the halogenated aromatic bisphenol, the viscosity'of the solution is sensed, an additional .amount of diacid halide is added in response to the sensed solution viscosity as the sensed solution30. viscosity approaches a predetermined solution viscosity limit and the addition of the diacid halide is terminate in response to the sensing of the predetermined solution viscosity limit.Halogenated aromatic polyesters prepared in accord¬5. ance with the process of this invention have recurring10. where X, which may be the same or different, is chlorine or bromine, Y, which may be the same or different is hydrogen, chlorine, or bromine, R, and R1 may be the sam or different and represent lower alkyl groups (e. g. , of 1 to 5 carbon atoms), or hydrogen, or together constitute15. a cyclic hydro-carbon group, and n equals at least 10 (e. g., n equals about 40 to 400). Commonly the aromatic polyester utilized in accordance with the process of this invention has a chlorine and/or bromine content of about 5% to 60^ by weight based upon the weight of the aromati20. polyester, (e.g., a chlorine and/or bromine content of about 25% to 50% by weight). As is apparent from the structural formula, the aromatic polyester is chlorinated and/or brominated in the sense that .these substituents ar directly attached to an aromatic ring. Preferably the25. halogen substituents are all bromine.The halogenate _aromatic polyesters conforming to the above-defined formula are prepared by reacting sub¬ stantially equimolar amounts of (1) an appropriate bisphenol and (2) a diacid halide such as isophthaloyl30, chloride, terephthaloyl chloride,', or mixtures thereof byI solution polymerization.Initially, the appropriate bisphenol is dissolved in a suitable solvent. A catalyst or acid acceptor is also dissolved in the solvent prior to the addition of the 5'. diacid halide. The bisphenols which are useful in the preparation of the polyesters having recurring units of the formula illustrated above have the structure:15- where X, Y, R, and R1, have the same significance as set forth hereinabove. Suitable bisphenols which are useful in the practice of this invention include 4,4'-methylene-2 , 2 * , 6, 6 * ,-tetrabromodiphenol; 4,4'-ethylidene-2,2' ,6,6'- tetrabromodiphenol; 4,4l-isopropylidene-2,2: ,6,6'- 20. tetrachlorodiphenol(i.e. , tetrachlorobisphenol A);2,2-bis(3-chloro 4-hydroxy phenyl) propane; 2,2-bis(3-bromo 4-hydroxy phenyl) propane; 1, -bis(5-bromo 4-hydroxy phenyl) ethane; 1 ,1-bis(5-chloro 4-hydroxy phenyl) ethane; 2,2-bis(3 chloro.5-hromo 4-hydroxy phenyl) 25. propane; bis(3-chloro 4-hydroxy phenyl) methane; bis(3, - dichloro 4-hydroxy phenyl) methane; 1,1-bis(3,5-dichloro 4-hydroxy phenyl) ethane; as well as their alkali metal salts. Preferred bisphenols useful in the practice of this 30. invention are.4,4'-isopropylidene-2, '6,6'-tetrabromodi- phenol also known as tetrabromobisphenol A and 4,4'- isopropylidene-2,2τ ,6,6' tetrachlorodiphenol also known as tetrachlorobisphenol A. Many brominated bisphenols of the above-described 5. structure are commercially available and may be prepared by the condensation of a lower alkyl ketone or aldehyde with tv/o molecules of the phenol and subsequently bro - inating and/or chlorinating the unsubstituted phenol. This reaction is usually carried out, with or without an 10. inert solvent, in the presence of an acid. This reaction is summarized in the case of X and Y being bromine in the following equations wherein R and R* have the meanings hereinabove described. techniques are employed, the solvent in which the bi¬ sphenol and catalyst or acid acceptor are dissolved and in which the reaction takes place should be inert and incapable of reacting with any of the components present30. therein. Furthermore, the solvent should be -a solvent for both the starting materials as well as the resulting polymer. This allows the solvent to help maintain the forming .polymer in a more workable form.Those suitable solvents which may be utilized in the 5. solution .polymerization technique described herein in¬ clude chloroalkanes, aromatic and chloroaromatic compounds such as methylene chloride, chloroform, tetrachloroethane, trichloroethane, chlorobenzene, chlorotoluene, dichloroethane, benzene, toluene, xylene, or mixtures 10. thereof.The catalyst or acid .acceptor is preferably a ter¬ tiary amine, (or a mixture of tertiary amines) which is capable of undergoing a reaction with the bisphenol to form a complex salt. Generally potential stoichiometric amounts15. of the bisphenol and the acid acceptorare employed al¬ though a molar excess of acid acceptor of about 5 to about 10% over the stoichiometric amount is preferred. Thus the ratio of the tertiary amine to the bisphenol is about 2:1 and preferably from about 2.1:1 to about 2.2:1. A20. bisphenol salt subsequently reacts with the diacid halide - and liberates an amine chloride.Suitable acid acceptors include any tertiary amine or mixtures thereof.Representative examples ..of'suitable tertiary amine 25. acid acceptors include triethylamine, diamino -2, 2, 2, bicyclo octane, tripropyl amine, dimethyl aniline, pyridine, dimethyla ine, and benzyl amine.It will be noted that halogenated aromatic polyesters of this invention are prepared by the condensation of 30. bisphenols with the diacid halides of isophthalic acid, terephthalic acid or mixtures thereof. The- use of a diacid halide as opposed to.other corresponding derivatives is critical, the direct preparation of polymers from bisphenols and free acids being normally n5. possible. These acid halides may be derived from a corresponding dicarboxylic acid by any one of several methods well known in the art such as reacting the respective acids with thionyl chloride. Thus, the diaci halide.is preferably utilized in the form of a diacid10. chloride.It is generally preferred to dissolve the diacid halide in the same type of solvent utilized to prepare t solution containing the halogenated bisphenol. Although this is not critical the employment- of a solvent provide 15. for a more accurate control of the addition of the diaci halide to the bisphenol containing solution.In preparing a preferred brominated aromatic poly¬ ester, the diacid halide will generally be utilized in t form of an aromatic acid chloride mixture of 45 to 75% 20. (e.g., 60%) by weight isophthaloyl chloride and correspo ■ ingly 55 to 25% (e.g., 40%) by weight terephthaloyl chloride. 'In preparing a preferred chlorinated aromatic poly ester, the diacid halide will generally be utilized as a aromatic acid chloride mixture of'90 to 40%, and prefer- 25. ably from 80 to 60% (e.g., 70%) by weight isophthaloyl chloride and correspondingly.10 to 60% and preferably form 20 to 40% (e.g., 30%) by weight terephthaloyl ' chloride.For smooth- operation in a stirred solution 30. polymerization, the resulting polymer product preferably should be about 10% or less on the basis of the total weight of the solvent although percentages as high as 25% may be utilized depending upon the molecular weights of the polymer.5. Generally substantially stoichiometric amounts of each reactant are employed; typical molar amounts of from - 1:0.8:2 to about 1:0.2:0.8, of -the ratio of bisphenol, isophthaloyl chloride and terephthaloyl chloride, respectively, are utilized.10. In calculating the amounts of reactants which are to be utilized to achieve a predetermined molecular weight the assumption is made that the reactants are pure and any error which may be introduced into said calculation as a result of this assumption is ignored. This assumption is15. made possible by the compensating effect of the feedback techniques described herein, which permit one to achieve a desired molecular weight in the absence of exact stoichio¬ metric calculations.Thus, the essence of the presently claimed invention 20. lies in the ability to terminate the addition of the di¬ acid halide to the bisphenol containing solution at the precise point necessary to obtain a polymer having a pre¬ determined molecular weight without making complex pre¬ liminary calculations to determine exact stoichiometric 25. requirements. The identificatio -of this termination point or end point is achieved by a feedback mechanism wherein the viscosity of the polymer containing solution is monitored or sensed during or after the addition of the diacid halide to the bisphenol containing solution. After the molecular weight which may be expressed a a weight average Mw and/or a-number average Mn and which is to characterize a final end product polymer-has been determined, the viscosity of a solution (herein referred5. to as the solution .viscosity limit) utilized in, accord¬ ance with the solution polymerization reaction which is indicative of a degree of polymerization sufficient to yield the said final end product polymer of the desired molecular weight must also be determined. This is10. achieved by relating the solution viscosity to molecular weight. Such a relationshp cannot be easily obtained directly and therefore is generally obtained indirectly expressing the molecular weight in terms of a standardiz viscosity which takes into account the variations of15. viscosity as a result of variations in the concentration of the solution measured.• The preferable standardized viscosity utilized to relate molecular weight to solution viscosity is inheren viscosity. As is well known in the polymer art, the in-20. herent viscosity is determined by measuring the relative viscosity of a 0.1% solution of the polymer at 25°C in a suitable solvent, such as chloroform or a 10/7 (w/w) mix¬ ture of phenoϊ/trichlorophenol. The viscosity of the polymer solution is measured relative to the solvent alon25. and the inherent viscosity (I,. Vs) is determined from the following equation:V,InV,I . V. = In the above formula, V is the efflux time of the solution, V-, is the e flux time of the solvent, and C is the concentration expressed in grams of polymer per hundered millilitres of solution. As is also known in the polymer 5. art, inherent viscosity is onotonically related to the molecular weight of the polymer.The molecular weight of the halogenated aromatic polyesters may be determined by any method known to those skilled in the art such as illustrated by W. Sorenson and 10. T. Campbell, Preparative Methods of Polymer Chemistry (1968),The inherent viscosity value which relates the specifi c predetermined molecular weight to the solution viscosity limit is referred to as the inherent viscosity limit. 15. More specifically, the inherent viscosity limit is hereby defined as the inherent viscosity of a polymer having a particular molecular weight which molecular v/eight corresponds to- the predetermined molecular weight of a polymer sought to be prepared in accordance with the solu-20.- tion polymerization process of the present invention.The solution viscosity limit is hereby defined as the viscosity of a solution containing a polymer having a particular inherent viscosity limit (i.e., a given pre¬ determined molecular weight) measured under conditions 25. which will be present during the actual solution poly¬ merization.Thus, a predetermined molecular weight of a given polymer can be expressed in terms of an inherent viscosity limit and a corresponding solution viscosity limit. The inherent viscosity limit is a standarized laboratory oriented value which can easily be empiricall related to a predetermined molecular weight of a polymer and which serves to link the solution viscosity limit t5. said predetermined'molecular weight. The solution viscosity limit is a commercially oriented parameter which is related to the predetermined molecular v/eight o a polymer by correlation with the inherent viscosity limit of the polymer and which serves to identify the10. end point at which the addition of -fche diacid halide to the bisphenol is terminated. As described above, the attainment of this end point is readily ascertained during the process of solution polymerization by directl sensing the viscosity of the solution containing the15- reactants and polymerproduct as the diacid halide is added to the bisphenol containing solution. Thus, when the sensed solution viscosity reaches a solution viscosi limit (i.e., the solution viscosity limit as determined by any sensing means) the addition or further addition o20. diacid halide to the bisphenol is terminated.It is to be emphasized that although utilization of inherent viscosity to relate solution viscosity to molecular weight is preferred, any standardized viscosit index such as kinematic viscosity or intrinsic viscosity 25. can provide the required relationship to permit the determination of the solution viscosity limit. The sensing of the solution viscosity may be accom¬ plished by any suitable-means, such as a Brookfield viscometer on withdrawn samples or an in-line viscomete 30. Alternatively, the pressure drop of a constant volume ' .flow- through a recycle loop may be monitored and corr¬ elated, to the solution viscosity.The preferred method for sensing the viscosity of the solution is to. measure the change in torque of a5. constant speed agitator which- is in contact with the polymer containing solution. Since the change in torque is a function of the change in solution viscosity the agitator can be calibrated to accurately determine the solution viscosity by any method well known to those10. skilled in the art.The sensing of the solution viscosity may be continuous or intermittent the only requirement being that the sensing' be sufficient to accurately indicate when the solution viscosity has reached the solution15. viscosity limit and to provide sufficient time to terminate the addition of the diacid halide before the solution viscosity limit is exceeded. It is therefore possible to tailor the rate of addition in accordance With the duration and type of sensing employed. Thus,20. the rate of addition may proceed in a manner similar to that utilized ina conventional titration process. In¬ itially, therefore, an amount of diacid halide which is less than the amount necessary to achieve stoichiometric equivalence v/ith the halogenated bisphenol and which is25. insufficient to drive the ..polymerization reaction to the extent necessary to reach the solution viscosity limit is rapidly added to the bisphenol containing solution. Said amount is determined by treating the reactants as if they contained no impurities and any error which might30. result therefrom is compensated for by the feedback mech- .anisrn described herein. Thus, as the purity of reactan and therefore the accuracy of the determination of such amounts' improves, the rate of addition during Hie initi stages of polymerization may be increased and the initi5. sensing may be held to a minimum. When proceeding in this manner, the first feed which contains substantial amounts of diacid halide may constitute from about 60 t about 95% of the amount of diacid halide necessary to achieve the stoichiometric equivalence for the bispheno10. After, the first feed the viscosity of the solution rapidly increases and begins to approach the solution viscosity limit. Further addition of the diacid halide therefore should proceed at a decreasingly slower rate to avoid over-shooting the solution viscosity limit. Th15. intermittent approach to sensing an addition of the diac halide to the bisphenol solution is generally applicable to the batch type of process.If it is desired to prepare the halogenated aromati polyester b a continuous process the addition of the20. diacid halide. to the bisphenol containing solution as we as the sensing of the solution viscosity is more conven¬ iently carried out in a continuous manner. Thus, the viscosity of the bisphenol containing solution may be sensed from the first addition of the diacid halide unti25. such addition is terminated. The rate of addition of th diacid halide to the bisphenol containing solution will be high during the initial stages of polymerization.and decrease to zero at the solution viscosity limit.In a preferred embodiment, the polymerization 30. reaction may be carried out in a continuous manner, by which the reactants are continuously introduced into the reaction, zone and the polymer product is continuously prepared and withdrawn. This may be achieved, for example by utilizing a cylindrical tube, having static5. mixers, as a reaction vessel. . The bisphenol containing solution is passed through the tube while adding the diacid halide at various points along the longitudinal axis in response to the viscosity of the polymer contain¬ ing solution as it is sensed at the outgoing portion of10. the tube. Thus, the diacid halide is added in large amounts at the downstream portion of the tube and in gradually decreasing amounts at positions further upstream in the tube.The final concentration of the polymer in solution 15. is about 3 to about 25%, preferably from about 5 to about 20% and most preferably from about 7 to about 1 %. At these, percentages of concentration, the solution vis¬ cosity will generally vary from about 1 to about 3000 ppise, preferabH-y from about 5 to about 2000 poise and 20. most preferably from about 10 to 1000 poise.Polymerization is effective at temperatures which may vary from about 0 to about 200°C, preferably from about 10 to about 100°C, and most preferably from about 15 to about 50°C, and at pressures which25. may vary from about 0.01 to 'about- 0 atmospheres and preferably from about 0.1 to about 10 atmospheres. Agitation of the reactantswill e sufficient to evenly disperse the diacid halide throughout the bisphenol containing solution to avoid'a build-up of the concen-30. tration of the diacid halide in a localized area within the reaction mixture. Such agitation may be supplied b any of the standard means of mixing such as by stirrer shaker, static mixer, spray nozzle or other flowing agitating means.5. After polymerization the polymer is generally recovered by washing the polymer containing solution wi dilute, aqueous hydrogen chloride to neutralize the excess acid acceptor. The polymer solution is then washed with water, to remove salts and collected in any10. suitable manner such as by evaporation of the solvent o by precipitation of the polymer in a suitable non-solven such as acetone or methanol The polymer may then be con¬ centrated to a desired spinning dope viscosity or dilute without isolation if the polymer is a solid, and there-15. after processed for shaping, e.g., spun or cast for maki fibers or films, respectively.Generally, the solution polymerization technique described herein is utilized to control the molecular 'weight of the halogenated aromatic polyesters in a manne20. sufficient to obtain a polymer having inherent viscosity (IV) limits which may vary from about 0.4 to about 1.7, preferably from about 0.6 to about 1.5, and most pref¬ erably from about 0.7 to about 1.2, which are indicative of polymers having a weight average molecular v/eight Mw25. of about 25,000 to about 150-,000 .preferably from about 41,000 to about 127,000, and most preferably from about 50,000 to about 97,000.'The above described inherent viscosity ranges will generally correspond to solution viscosity limits of 30. about 1 to about 3000 poise, typically from about 5 to about 1000 poise and preferablyfrom about 30 to about 95 poise at 'the typical final solution concentrations described above.The halogenated aromatic polyesters prepared by the 5 . - process o the presently claimed invention may be diss¬ olved in a suitable spinning or casting solvent, such as methylene chloride or tetrahydrofuran and formed into a shaped article, such as a fiber or film.BEST MODE OF CARRYING OUT THE INVENTIONThe invention may be put into practice in various 10. ways and certain specific embodiments will be given to illustrate it with reference to the accompanying examples. All parts and percentages in the examples as well as the remainder of the specification are by weight.unless other¬ wise specified.EXAMPLE 115. The objective of this example is to obtain a polymer with an inherent viscosity between 0.9 and 1.1 which corresponds to a weight average molecular weight (AW) Mw of from 68,000 to about 87,000 and a solution viscosity limit of from about 40 to about 71 poise. Thus, a20. brominated aromatic polyester containing bromine chem¬ ically bound to an aromatic ring and possessing the structural formula heretofore illustrated where X and Y are bromine groups, R and R' are methyl groups and n is about 100 is prepared by solution polymerization in the25. following manner.The amounts of reactants utilized in this example are based on theoretical stoichiometric requirements to achieve the desired molecular weight and no correction is made for other factors such as impurities in the reactants which 30. might affect the theoretical requirements. Thus, parts by weight of 4,4' - isopropylidene -'2,2'. 6,6' - tetrabromodiphenol are added to a reactionvessel con¬ taining about 1800 parts by weight of methylene chloride and 80 parts by weight of triethylamine with agitation.5. A solution of a mixture of diacid halide comprising 44.7 parts by weight of previously distilled isophth¬ aloyl chloride and about 29.8 parts by weight of prev¬ iously distilled terephthaloyl chloride and 213.8 parts by weight of methylene chloride is then added at a rate10. of 3«37 liters per minute to the bisphenol containing solution over a period of time of about one half hour, and at a temperature of about 30°C. The viscosity of the resulting solution is then sensed by measuring the viscosity of an in-line sample at 30°C with a Brookfield15. viscometer (spindle no, 4 -6 ) and found to be less than 2 poise. The viscosity was found to be independent of the rate.of shear.An additional amount of the same diacid halide solution which has been diluted to about 2.5 percent by20. weight is then added.at a rate of 0.76 liters per minute. After a period of time ofabout 20 to 30 minutes the •solution viscosity increases to about 2 poise at 30°C and the flow rate is decreased to 0.26 liters per minute over a period of about 20 to 30. minutes. The viscosity25. of the solution is then sensed in the manner described above and found to be 20 poise. The previously diluted diacid halide solution is then charged to the reaction vessel at a flow rate of about 0.11 liters per minute in progressively shorter increments until the solution30. viscosity is sensed as being 45 poise at 30°C. This solution viscosity corresponds to an inherent viscosity limit of about 0.95 which meets the objective. At the termination of addition of the diacid halide solution the polymer is present at a concentration of about 10% by 5. weight in the final reaction solution.The polymer containing solution is then washed with a 5% aqueous solution of HC1 and decanted to remove the triethylamine as a salt. This procedure is repeated four times. The polymer is then washed with distilled water 10. to remove HC1 until the pH remains constant. The washed polymer is then precipated with methanol and recovered for molecular weight determination to confirm that the target molecular weight has been achieved.The final mole ratios of the components utilized are 15. 1 part tetrabrominated bisphenol, 1.02 parts of 60:40 mixture of isophthaloyl and terephthaloyl chloride and 2.15 parts triethylamine.The results of this example are summarized in STable 1.' EXAMPLE II20. Example 1 is repeated with the exception that the objective is to prepare a polymer having an inherent viscosity of about 1.1 to about 1.2 which corresponds to a weight average molecular- Weight (AW) Mw of from about 87,000 to about 97,000 and a solution viscosity25. limit of from about 71 poise to about 95 poise. The same amounts of the reactants were used as in Example 1.The results of this example are summarized in Table 1. Table I. ,5. Solution InherentViscosity ViscosityExample' Limit Limit AW (Mw)I 45 poise ' 0.95 73,000II 84 poise 1.15 92,000EXAMPLE III10. . The objective of this example is to describe how the solution viscosity limit is determined. A target weight average molecular weight of 97,000 is determined wherein n of the structural formula is about 150 and the polymer utilized in Example 1 having said predetermined molecular15. weight is prepar'ed. This is achieved by first determinin the exact stoichiometric requirements necessary to obtain a polymer of the desired molecular weight, taking into account such factors as purity of. the reactants, solvent reactivity, side reactions of the diacid chlorides and20. amine acid acceptors and polymer hydrolysis. Thus, 201.7 parts of 4,4' - isopropylidene - 2,2', 6,6'- tetrabromodi phenol is added to a reaction vessel containing about . 1800 parts by weight ethylene chloride and 82 parts by weight triethylamine under agitation.A solution of a diacid halide mixture comprising 25. 46.0 parts by weight of previously distilled isophthaloyl chloride, 30.8 parts by weight of' previously distilled terephthaloyl chloride and 320 parts by weight methylene chloride is then rapidly and completely added to the ; solution containing the bisphenol in a single increment 30. and reacted-therewith' at a temperature of 35 C. The reaction vessel is cooled to terminate the reaction after a period of 1 hour when the polymer has achieved a maximum' inherent viscosity of 1.2 which corresponds to the desired molecular weight. This inherent viscosity is5. then designated as the inherent viscosity limit for said target molecular weight. A sample of the resulting poly¬ mer solution, wherein the polymer is present in an amount of 10% by weight thereof, is removed, from the reaction vessel and maintained at a temperature of 30 C. The10. solution viscosity of this sample is then determined by a Brookfield viscometer (spindle no. 4-6) and found to be 95 poise. The viscosity was found to be independent of the rate of shear. This solution viscosity is then designated as the solution viscosity limit for said target15. molecular.weight. This procedure is repeated several times utilizing different target molecular weights. A table is then drafted which lists different target molecular weights and corresponding inherent viscosity limits and solution viscosity limits (e.g., at a typical20. polymer concentration described herein). Such a table is provided for a polymer prepared by reacting tetrabrom- obisphenol A and a 60:40 mixture of isophthaloyl: terephthaloyl -chloride at Table II.TABLE II25. Target Ihher-ent'' :,, . Solution ViscoisityWeight Average _ Viscosity • Limit at 10%Molecular Weight Mw • Limit Polymer Cone.50,000 0.7 19 poise55,000 . ' 0.8 28 poise68,000 0.9 40 poise77,000 1.0 52 poise β87,000 1.1 71 poise97,000 1.2 95 poise30. 107,000 1.3 140 poise INDUSTRIAL APPLICABILITYThe presently claimed process avoids the necessity for careful and mostly weighing and analysis procedures necessitated by the raw materials used to prepare .the polymer and allows for the production of a 5. uniform product of a predictable molecular weight range.The halogenated aromatic polyesters described here¬ in may be used to produce a number of inherently non- burning fibrous materials which offer the public a great degree of fire safety, particularly when fibrous article 10. are required for use in fire-control environments, e.g., children's sleepwear, suits for fire fighters, hospita _lι furnishings, and uniforms for military and civilian personnel.N | CLAIMS1*. A process for preparing a halogenated aromatic polyester' by the solution polymerization of a halogenated bisphenol and a diacid halide characterized in that the halogenated aromatic polyester has a predetermined molecular weight and is of the following recurring structural formula: where X, which may be the same or different, is chlorine or bromine, Y, which may be the same or different, is hydrogen, chlorine or bromine, R and R', which may be the same or different, represent lower alkyl groups, or hydrogen, or together constitute a cyclic hydrocarbon •group, and n-equals at least 10, the diacid halide being selected from the group consisting of isophthaloyl chloride, terephthaloyl chloride and mixtures thereof and in that the process comprises providing a solution com¬ prising(a) an organic solvent(b) a halogenated aromati c'bisphenol, and(c) an acid acceptor, adding the diacid halide to the said solution under conditions such that the said diacid halide reacts with the said halo¬ genated aromatic bisphenolto form a polymer, sensing the viscosity of the solution containing the resulting polymer and terminating the add¬ ition of the diacid halide in response .to the sensing of a predetermined solution viscosityIjuREΛZrO PI limit (as defined herein).2.. A method as claimed in Claim 1 in which the viscosity of the -solution containing the halogenated aromatic bis¬ phenol is sensed as said diacid halide is added thereto forming the polymer and thereby causing an increase in solution viscosity and the.addition of the diacid halide is controlled in response to the sensed solution viscosity as the sensed solution viscosity approaches a predetermined solution viscosity limit; and the addition of the diacid halide is terminated in response to the sensing of the predetermined solution viscosity limit.3. A process as claimed in Claim 1 in which the said diacid halide is added to the solution of halogenated aromatic bisphenol in an amount less than the amount necessary to achieve stoichiometric equivalence with the halogenated bisphenol, the viscosity of the solution is sensed, an additional amount of diacid halide is added in r sponse to the sensed solution viscosity as the sensed solution viscosity approaches a predetermined solution viscosity limit and the addition of the diacid halide is terminated in response to the sensing of the predetermined solution viscosity limit.4. A process as claimed in Cla:μn 1, 2 or 3 in which the said halogenated aromatic polyester' is a product of tetrabromobisphenol A and a mixture of 45 to 75% by weight isophthaloyl chloride and correspondingly 55 to 25% by weight terephthaloyl chloride,_5. A process as .claimed in Claim 4 in which the said halogenated aromatic polyester is a product of tetrabrom¬ obisphenol A and a mixture of about 60% by weight isoph¬ thaloyl chloride and about 40% by weight terephthaloyl £.0 ,chloride .6. A process as claimed in Claim 1, 2 or 3 in which the said halogenated aromatic polyester is a product of tetrachlorobisphenol A and a mixture of 40 to 90% by weight isophthaloyl chloride and correspondingly 60 to 10% by weight terephthaloyl chloride.7. A process as claimed in Claim 6 in which the halo¬ genated aromatic polyester is a product of tetrachloro¬ bisphenol A and a mixture of about 70% by weight isop¬ hthaloyl. chloride and correspondingly about 30% by weight terephthaloyl chloride.8. A process as claimed in Claim 1, 2 or 3 in which the predetermined molecular weight, is a weight average molecular weight M w which is in the range from about 25,000 to about 150,000.N9. A process as claimed in Claim 8, in which the solution viscosity limits which correspond to said molecular weights vary from about 1 to about 3000 poise.0. A halogenated aromatic polyester whenever made by a method as claimed in Claim*-/), 2 or 3. | CELANESE CORP | ROSENTHAL A; SAKOWITZ M; STACKMAN R |
WO-1979000077-A1 | 1,979,000,077 | WO | A1 | EN | 19,790,222 | 1,979 | 20,090,507 | new | A61B19 | A61L1, A61L3, B65D51 | A61B19, A61L2, B65D51 | A61B 19/02P, A61L 2/26 | STERILIZED STORAGE CONTAINER AND METHOD | The invention pertains to the steam sterilization of objects (100) in a container (10) which serves as the storage container for the sterilized objects until the latter are ready for use. The container (10) automatically seals itself during the sterilization cycle and before removal from the sterilizer so that the container contents are maintained in an aseptic environment without danger of recontamination during storage. In the Figures 1-13 embodiments, a valve opening (36) permits steam to circulate into a container (10) and permits condensation to drain from the container while the valve (52) is open. Steam within an expandable chamber (66), (166), captured through the closing of a temperature responsive valve (92, 192), causes the chamber to expand when pressure drops at the end of a sterilizing cycle, and closes the valve (52). A lid (12) and gasket (16) permit steam to be withdrawn from the container but prevent air flow into the container. In the Figures 14-16 embodiments, container bottom wall (314) is sloped so that condensation will flow to the edges. A lid (312) is held partially open by an actuator pin (344) connected to an expandable chamber (342). Steam captured through valve (352, 354) expands in response to the pressure drop at the end of the sterilizing cycle to expand the chamber to withdraw the pin and allow the lid to close. In the Figures 17-22 embodiments, an expandable chamber (440) moves a lever mechanism (422) to seal a container at a predetermined pressure after a final vacuum in a sterilizing cycle but before the container is removed from the sterilizer. | STERILIZED STORAGE CONTAINER AND METHOD Technical Field This invention relates to an improved system for storing items while they are being sterilized, while they are being stored awaiting use, while they are in the process of being used, and after they have been used and are awaiting resterilization. The system is particularly useful in connection with the sterilization and storage of medical items, such as surgical instruments.Background of the Invention The most commonly used method for sterilizing surgical instruments and other medical items is to place them in towels which are enclosed in a sheet and taped shut for placing in a sterilizing autoclave. Sterilizing steam applied to the interior of the autoclave penetrates the porous materials surrounding the items to be sterilized. Moisture is removed by a vacuum drying cycle within a vacuum autoclave.When pressure is then returned to normal by admitting room air, unsterile air and lint from the towels is drawn into the center of the package. When the package is removed from the autoclave and cooled, additional room air circulates into the package. Thus, the items are immediately contaminated to some extent. If the package is not used immediately and placed in storage for a period of time, it must be returned to the autoclave for resterilization. It is estimated that two-thirds of sterilization work load*in many hospitals is for items that were not used within the shelf life of the pack. This, of course, is an expensive and' inefficient procedure which adds to the skyrocketing costs of medical treatment. Thus, a need exists for a practical and reliable system for handling sterile items and for maintaining sterility. German patent No. 1,642,161 and U.S.A. patents 2,092,445; 2,997,397; and 3,468,471 disclose sterilizing containers and provide some improvement over the towel method discussed above, but they still do not completely sterilize and seal the containers' contents in a dry essentially atmosphere free condition.Disclosure of the Invention The present invention is a combination of U.S. application -No. 895,239,' filed April 10, 1978 and U.S. patent application. Serial No. 821,042, filed August 1, 1977, which is a continuation-in-part of U.S. patent application. Serial No. 734,228, filed October 20, 1976, which in a continuation-in-part of U.S. patent application, Serial No. 703,044, filed on July 6, 1976, which is an continuation-in-part of application Serial No. 640,824, filed December 15, 1975. The latter four U.S.A. patent applications and two earlier U.S.A. patent applications. Serial No. 710,521, filed August 2, 1976 and Serial No. 710,522, filed August 2, 1976 in the name of Roger S. Sanderson disclose containers in which the items to be sterilized are placed within the container and the container is then placed within an autoclave or other sterilizer. The container is initially sufficiently open to permit the sterilizing environment to circulate within the interior of the container and the container is then sealed at an appropriate stage to maintain sterility. Further, - even when closed, the container in the earlier joint inventor cases is constructed such that steam can escape or be withdrawn from the container when the pressure on the interior of the container exceeds the pressure on the exterior but does not permit flow into the chamber. Consequently, the container is usually essentially dry with a vacuum type autoclave wherein a vacuum is 'applied to the container at the end of the steaming cycle. 'Also, only a slight amount of moisture remains in the - comtainer with a gravity-type autoclave for most sterilizing operations, and this moisture can be absorbed by a small quantity of dessicant.However, with loads involving a considerable mass, such as a large quantity of surgical instruments, steam must be circulated through the autoclave for a long time to heat the load to the necessary sterilizing temperature. During this operation, a significant amount of steam condenses on the colder metal. Although this condensate is eventually sterilized in the autoclave, it is desirable that the container in which the load is stored be as dry as possible. In German patent referred to above, the container provided has a valve in its lower wall which remains open until the temperature drops at the end of a steaming phase of a sterilizing cycle. Consequently, any condensate occurring drains from the container through the open valve. However, that container is not trμly sealed in that unsterile air is admitted through a relief valve.In one form of the present invention, a valve is positioned in the lower wall of a container which remains open until the pressure drops at the end of the sterilizing cycle, which seals the - container from further flow into the container. The valve closing means includes an inflatable chamber which is initially open to high pressure steam in an autoclave, and is then automatically closed in response to the steam temperature, capturing a quantity of high pressure steam within the expandable chamber. This steam causes the chamber to expand at the end of the steaming phase of*the cycle when there is a significant pressure drop. The force created by the expanding chamber is employ¬ ed to close the valve in the container wall. The container lid, gasket and base are- constructed such that residual steam can be with¬ drawn from the container even after the valve is closed when the pressure on the exterior of the container is less than the pressure on the interior of the container. Moreover, when the pressure on the exterior is 'increased, this pressure holds the valve in closed position and draws the lid more tightly on the base.In another form of the present invention, an inflatable chamber-type actuator is employed to ensure that the container is held open until after the end of the steaming phase to permit condensate to drain from the container and the container is then automatically closed. More specifically, in this arrangement, the container is formed with a generally flat base having no side walls, with the center of the base being raised slightly from the periphery so that condensate can flow to the edge of the container. The lid, which includes a top wall and depending side walls, cooperates with the base to close the container. The lid is initial¬ ly held open on one side by an element extending between the lid and the base. The element is connected to be withdrawn by the force produced by an expandable chamber, which expands as the pres¬ sure drops within the autoclave at the end of a pressure steaming phase. Thus, instead of the expandable chamber closing a valve, it simply releases the lid and allows it to fall into position. A simple, separate relief valve may be provided for manually relieving the vacuum later formed in the container, to permit opening of the container. In a preferred form of the invention, the element holding the lid open is a pin which is connected to one end of a generally disc-shaped expandable, balloon-like chamber, with the pin extending through the chamber and out the other end. The chamber is positioned against an upwardly extending support on the periphery of the base with the pin extending through a hole in the support to hold the lid spaced from the base. Thus, when the chamber expands, the end of the chamber which is connected to the pin moves away from the base, withdrawing the pin from its lid supporting position. The expandable chamber actuator is constructed so that the lid is allowed to close before the pressure within the autoclave or other sterilizer reaches ambient pressure. This ensures that the , lid is closed before any unsterilized air is allowed to enter the autoclave at the completion of its cycle. This provides complete sterility with either a vacuum-type autoclave, wherein a final vacuum is applied after the end of the steaming phase, as well as with a so-called gravity-type autoclave wherein a final vacuum is not applied. While this arrangement provides the desired result and is necessary with present-day technology, a significant cost saving can be made in the construc¬ tion of the container if the air entering the autoclave at the end of the final vacuum in a vacuum-type autoclave would be sterile. With present-day autoclaves, the manner by which pressure is equalized in the autoclave at the end of the final vacuum is simply to open a valve which permits filtered outside room air to enter the autoclave. Although the filter provides some degree of sterility, it does not provide the level of sterility which is desired 'to minimize the possibility of contamination within the container. . Consequently, the presently preferred approach is 5. - to cause the container to close as the autoclave pressure is falling but before it reaches its lowest pressure. Nevertheless, since the container lid, base and gasket are constructed to permit fluid flow out of the container even after the 0 container is closed, a very high vacuum is attained within the container, particularly in a vacuum-type autoclave. Because of this, it is naturally necessary that the container be constructed to withstand such high vacuum. For a variety of 5 reasons it is desirable to utilize transparent plastic to form the container; and hence, it is necessary that the walls be relatively thick to withstand the pressure. If in the future autoclaves are provided which include a filter that essentially 0 sterilizes the air which is introduced into the autoclave at the end of the cycle to equalize pressure, it would not be necessary to close the container before the low pressure point during the final vacuum of an autoclave cycle; but instead, 5 the container could be closed during the time the pressure is rising from_ the low point, since the air being introduced to equalize pressure would be sterile. It would only be necessary to have the container closed before it is removed from the 0 .autoclave and exposed to unsterile air. Closing the container with a lesser vacuum existing within it would lower the strength requirements for the container so that the walls could be made thinner. This of course would result in a substantial 5 savings of material.Thus, in another embodiment of the invention, there is provided a mechanism which holds theOMP container open, until the pressure is rising after the maximum vacuum point is reached during the final vacuum phase of an autoclave cycle. This mechanism employs an inflatable chamber means as an actuator to automatically control the closing of the container. The expansion of the chamber is used to trigger a two-step closing operation, and the later contraction of the chamber.as pressure surrounding the chamber increases, causes closing ' of the container.In a preferred arrangement of this two-step closing process, a lever is pivotally mounted on the periphery of the container base with one end of the lever extending between the lid and the base to hold initially the lid spaced from the base. A spring urges the lever into that lid holding position. As the pressure drops at the end of the steaming phase of an autoclave sterilizing cycle, an inflatable chamber expands in the manner discussed above, and the chamber is positioned so that its expansion provides a force which pivots the lever to withdraw the end of the lever which is initially supporting the lid. However, this pivoting movement simultaneously causes the other end of the lever, or a pin attached to it, to move beneath the lid so that when the lid' falls from the support provided by the first end of the lever, it only falls a small amount so that it is still retained by the other end of the lever.The inflatable chamber continues to.expand until the maximum vacuum condition is reached; however, as outside filtered air is then admitted to the autoclave, the increasing pressure surrounding this sealed inflatable chamber causes the inflatable chamber to once more contract. This in turn permits the lever to be once more pivoted in response to the urging of the'spring and withdraw the second end of the lever which had been supporting the lid. Consequently, the lid falls into closed position. The point at which the lid finally closes may be easily predetermined as desired by controlling the length of the pin or second end of the lever which supports the lid. Thus, it can be seen that the improvements described herein provide versatility to insure complete sterility with present-day sterilizing equipment and yet readily adaptable to improvements which may occur in such equipment.Brief Description of the Drawing Fig. 1 is a perspective view of the container forming one version of the invention; Fig. 2 is a cross-sectional view of the contain¬ er on lines 2-2 of Fig. 1 illustrating the overall arrangement and the slope of the bottom wall of the container;Fig. 3 is an exploded perspective view of the container valve and valve closing mechanism;Fig. 4 is an enlarged cross-sectional view of the container valve and valve closing mechanism shown on the container before being actuated by the sterilizing cycle;Fig. 5 is a cross-sectional view of the structure of Fig. 4 after the valve has been moved into sealing position on the container valve seat by the expandable chamber forming the valve closing mechanism;Fig. 6 is a cross-sectional view of the structure of Fig. 4 showing the valve held in place by pres¬ sure on the exterior of the container and showing the expandable chamber in retracted position; Fig. 7 is a cross-sectional view of the structure of Fig. 4 as it appears after the valve f O P1 has been placed in position by the expandable chamber near the end of the steaming phase of a gravity autoclave, but before the valve is tightly drawn into sealing position on the container valve seat by the vacuum created in the container as it cools; Fig. 8 is a schematic illustration of a vacuum autoclave cycle indicating the points on the pressure and temperature curves at which the operation of the mechanism curves;Fig. 9 is a sketch similar to Fig. 8 but for gravity autoclave;Fig. 10 is a fragmentary view showing a varia- tion of the expandable chamber serving as a dessicant bag;Fig. 11 is a fragmentary view showing another variation of the container in the previous applica¬ tion wherein the lid of the container is initially held open;Fig. 12 is a cross-sectional view of a piston- type expandable chamber valve closing mechanism shown before the chamber has expanded to seat the valve; Fig. 13 is an elevational view of the structure of Fig. 12 showing the components after the valve has seated;Fig. 14 is an exploded perspective view of a preferred form of the container of the present invention;Fig. 15 is an enlarged cross-sectional view of the actuator mechanism shown in Fig. 14 showing the mechanism in its initial condition wherein it is supporting the lid spaced from the base of the container;Fig. 16 is a view similar to that of Fig. 15 but showing the expandable chamber expanded so that the # pin is withdrawn and the lid is in its closed position;Fig. 17 is a partial plan view of an embodiment of the invention illustrating the mechanism which does not permit the container to close until the pressure is rising after a final vacuum in a sterilizing cycle;Fig. 18 is a cross-sectional view on lines 18- 18 of Fig. 17, showing the lid being supported by one end of a lever;Fig. 19 and 20 are respectively similar to Fig. 17 and 18 with the expandable chamber expanded and ■ the other end of the lever supporting the lid in the open position; and Fig. 21 and 22 are similar to Figs. 17 and 18 respectively with the inflatable chamber deflated and with the lid in a closed position. Best Mode for Carrying Out the InventionReferring now to Figs. 1 and 2, there is shown a container 10 having a cover or lid 12 closing the open upper side of a base 14 and seated on a gasket 16 extending between the base and the lid. As can be seen, the container has a generally oval or race track configuration and the lid has an upper, wall 18 which slopes gradually upwardly towards the center. The purpose for the oval shape and the upwardly curving wall 18 is to provide strength to the container when it is subjected to an exterior pressure considerably higher than the interior pressure. The cover 12 further includes a peripheral flange portion having a generally vertical internal wall 20 which joins at its upper end a downwardly and outwardly sloping flange 22. A tab 24 extends outwardly from the bottom of the flange 22 at one end of the container.The base 14 includes an irregular but generally upwardly extending side wall 26 formed integral withOMPI Λ. W1P0 a bottom wall 28 and a downwardly extending peripheral leg structure 30. The side wall 26 terminates at its upper end with a short vertically extending 5 portion 32 which extends into the downwardly '. - extending groove 34 formed by the inner surface of the lid flange 22 and the outer surface of the lid wall 20. As can be seen from Fig. 2, the lid wall 20 fits within the upper end of the base wall 32. 0 The portion of the side wall 26 below the upper por¬ tion 32 extends outwardly to a point where the lower portion of the wall 26 generally aligns with or forms an extension of the exterior surface of the lid flange 22. 5 The gasket 16 is made of flexible rubber-like material which can withstand the temperatures of an autoclave operation and yet provide an adequate seal. The gasket 16 includes an inner vertical portion which fits snuggly around a groove in the wall 32 0 on the upper end of the base side wall 26. The gasket 16 further includes a downwardly and out¬ wardly extending flange portion which mates with the inner surface of the lid flange 22.The bottom wall 28 of the base slopes generally 5 toward a valve opening 36 in the right end of the base as viewed in Fig. 2. The base leg 30 extends in¬ wardly at the right end of the base to form a recess 38 in which is positioned a valve and valve closing assembly 40 which cooperates with the valve opening 0 36. More specifically, the recess 38 is formed by a sloping leg wall 42 which extends in a generally cylindrical configuration about 180 degrees to partially enclose the valve and valve closing assembly 38. The wall 42 is further connected to a bottom 5 support wall 44 which extends generally perpendicular to the side wall 42 and joins with a stub leg wall 46 on the periphery of the base leg. A hole 41 is formed in the bottom wall 44 for positioning the assembly 40. As can be seen by the broken lines in Fig. 2, ' a second container 48 may be stacked on the lower container 10 with the leg of the upper container being positioned on the lid 12 in the groove formed by the lid side wall 20 and by the outer periphery of the lid upper wall 18. As seen from Fig. 1, each end of the lid has a shallow recess 50 adapted to receive the wall portions 44 and 42 of the upper container 48. A recess 50 is formed on each end of the lid so that the user need not worry about orientation of the container 48 when it is being stacked on the container 10. Naturally more than two containers may be stacked if desired.Referring now to Figs. 3 and 4, the valve and closing mechanism 40 may be seen to include a valve 52 which is a flexible resilient member molded of silicone rubber or other rubber-like material which can withstand steam temperatures while maintaining its resiliency. The valve includes a base 54 which when unrestrained has a generally saucer-shaped configuration with the upper surface of the base 54 forming the sealing surface against the container when the valve is closed. Attached to the central portion of the base 54 is an upwardly extending generally cylindrical stem or core 56. As may be seen from Fig. 4 and 6, much of the core • 56 is hollow opening to the lower side of the base 54. The upper end of the core* 56 extends through the opening 36 in the container lower wall/ the end 57 of the core 56 having a solid conical shape to facilitate insertion of the core into the opening 36. The portion of the core 56 actually extending through the opening 36 as viewed in Fig. 4 includes three radially extending circumferentially spaced-BUREOMP, , W1P ribs 58. Each rib further has* a radially extending leg 60 which has a tapered upper surface 60a which engages the lower edge of the opening 36 with the assembly positioned as shown in Fig. 4. ; - A tab 62 extends radially outwardly from one edge of the valve member base 54 to form a convenient element for removing the valve member from the valve opening 36. The assembly 40 further includes a valve closing means comprising a generally disc-shaped hollow ember 64 which is made of flexible rubber¬ like material and defines an expandable interior chamber 66. Since the member 64 is flexible and stretchable, it might be thought of as a balloon or bellows-like member. The bottom side of member 64 includes a centrally located thickened throat 68 which defines a circular opening into the chamber 66. A circular plug 70 snaps within the throat 68 in the lower wall of the member 64. More specifically, the plug 70 includes a side wall 72 which slopes downwardly and outwardly and is slightly larger in diameter than the throat 68. A side wall 72 further includes an outwardly'extending flange 74 that forms a continuation of the upper wall 75 of the plug. The throat 68 snuggly engages the side wall 72 of the .plug and the flange 74 snuggly engages the lower wall of the chamber 66 surrounding the throat 68. While the plug 70 snaps into position in the throat 78 to close the chamber 66, there .. is further provided a resilient ring shaped retaining element 77, which surrounds the exterior of the throat 68 holding it in tight engagement with the plug side wall 72. The plug 70 further includes a lower guide portion 78 having a curved exterior which fits within an opening 41 in the container wall portion 44 which supports the valve and valve actuating assembly 40.A valve passage 82 extends centrally through the plug from the lower portion 78 and upwardly into a tubular portion 84 that extends above the upper wall 76. The upper end of the tube 84 is closed by a plate or wall 86. A hole 88 extends radially through the tube 84 to place the chamber 66 in fluid communication with the atmosphere around the assembly 40.Formed in the upper wall 76 of the plug 70 is an annular recess or groove 90 in which is positioned a thin band 92 which surrounds the tube 84 and extends over the valve opening 88. The band 92 is made of heat shrinkable material which shrinks and becomes permanently rigid at a predetermined temperature.The balloon member 64 further includes an upwardly extending nipple 94 which snuggly fits within the cylindrical recess 55 in the lower wall of the valve base 54 as seen in Fig. 4. The interior of the nipple 94 is hollow and is open to the chamber 66 when the chamber is .expanded; however, in the position of Fig. 4, the upper wall 86 of the tube 84 of the plug 70 engages the lower end of the nipple 94 and thereby limits the contraction of the chamber 66. Loosely surrounding the nipple 94 is a heat shrinkable band 96. Operation of Embodiment of Figs. 1 - 7 in a Vacuum AutoclaveReferring to Fig. 2, the container lid 12 is removed and the articles 100 to be sterilized are placed within the base 14. They are then loosely covered by a thin sheet of transparent plastic material 102 which can withstand sterilizing steam temperatures. The lid 12 is then loosely placedOMP1 in position on the base 14 with the interior of the inner surface of the flange 16 engaging the outer surface of the flexible gasket 22. In this position, the lid or cover is closed in the sense that air ' * cannot flow into the container past the gasket but the cover is not fully closed onto the base. A valve and valve closing assembly 40 is . positioned within the recess 38 as shown in Figs. 2 and 4. The components of the assembly 40 are usually provided in an assembled conditioned wherein the band 96 is first loosely positioned on the nipple 94 of the valve actuating member64 and •the nipple is then pressed into the recess 55 in the lower end of the valve member. The valve is retained in this position by a slight friction fit. The assembly 40 is therefore inserted into the recess 38 as a unit. Since the components are flexible, the upper end 57 of the valve core may be easily inserted into the container valve opening 36, allowing the lower end of the valve actuating member 64 to be snapped into position. The lower surface 78 of the core 70 conforms to the hole 41 in the container support wall 44 to properly align the assembly. The alignment ribs 48 on the valve core 56 properly align the valve with respect to the hole 36. Also, the outwardly extending lugs 60 limit the inward movement of the valve to tell the user of the equipment that the assembly is properly positioned. The tolerance of the components are relatively loose - but yet the design is such that precise alignment is not critical to obtain proper seating of the valve.The valve closing assembly is primarily designed for use in a sterilizing apparatus which 5 includes a high pressure steam cycle. Two widely used sterilizers are the so-called gravity autoclave and the vacuum autoclave. An example of the pressure- UREA rOMPI' and temperature cycles in one'type of vacuum autoclave is illustrated in Fig. 8. The horizontal line 104 represents time. T represents a temperature curve and P represents the pressure curve, with the line 104 indicating normal room temperature and pressure. When the container 10 is placed within the vacuum autoclave, a first vacuum environment indicated by the section Tl of the pressure'curve is first applied. Most of the unsterilized air within the autoclave is withdrawn as is the air within the container 10 since the interior of the container is in communication with the interior of the autoclave by means of the valve opening 36 in the bottom wall of the container. The pressure within the autoclave is then once more allowed to return to ambient pressure by allowing steam into the chamber. A second vacuum cycle P2 on the pressure curve shown on Fig. 8 is then applied which withdraws the steam within the autoclave which has mixed with the small amount of remaining unsterile air. In some sterilizers, additional vacuum cycles of this type are employed.High pressure steam is then introduced into the autoclave causing the pressure as well as the temper¬ ature to rise as indicated by the curves and P. The temperature and pressure curves are shown coincident at this time in that they both rise at the same time and the units of measurement employed are assumed to cause the curves to move in a coincident manner. It should be understood that this is not intended to be a precise showing of the actual curves but only to illustrate that the temper¬ ature and pressure are both rising to their maximum levels during this phase. The high temperature steam of course circulates into the interior- of the container by way of the valve opening 36. Also, the- ϋRE OMP high pressure high temperature steam also circulates into the chamber 66 by way of the valve passage 82 and the valve opening 88, noting -that the cylindrical valve element 92 is spaced from the opening 88 to permit such.flow. Note that even if the valve band 92 is positioned loosely over the opening 88, the pressure differential between the chamber 66 and the surrounding autoclave pressure causes the steam to flow into the chamber 66.When the temperatures and pressures are near their maximum, the heat of the steam causes the heat shrinkable sleeve 92 to shrink to its position shown in Fig. 5 wherein it closes the opening 88, thereby capturing a volume of high pressure high temperature steam within the chamber 66. This point 106 is shown in Fig. 8.The steaming cycle continues for a desired period of time. Most autoclaves are adjustable to vary the duration of the steaming portion. The graph shown in Fig. 8 illustrates the steaming cycle to be of relatively short duration; however, the duration should be adjusted to fit the load within the container. A load requiring a particularly long period of time is one which includes a large quantity of metal elements having considerable mass. For example, a large quantity of surgical tools would have considerable mass. Even more demanding, during the testing of the container, a load of steel bolts were placed in the unit. Such a load requires a considerable period of time for adequate sterilizing in that it takes a considerable quantity of steam to heat the entire mass of the load to the desired sterilizing temperature. The surface of the heavy metal items will remain relatively cool until the interior of the items are heated because of the conductivity of the material. As the hot steamOMPI Λ WlPO -Λ>. strikes the cooler metal, some of the steam condenses and drips into the floor or bottom wall 28 of the container. Although this liquid would be sterile at the end of a sterilizing cycle, it is desirable that the water be removed from the container so that the container will be as dry as possible during storage. It is for this reason that the bottom wall 28 of the container is slightly sloped so that the water will flow towards and out the opening 36. Regardless of the length of the steaming cycle, the valve 36 will remain open in that there is no force for closing it. However, when the steaming cycle is interrupted, the pressure quickly drops as illustrated by the section P3 of the curve. A final vacuum cycle is then applied to withdraw the steam as indicated by the curve section P4. Following this, the vacuum is removed by allowing the introduction of filtered exterior air so that the • pressure within the autoclave returns to room pressure.As the pressure in the autoclave is dropping from its maximum, the captured pressure within the chamber 66 causes the balloon 64 to expand. Since the pressure drops rapidly into a vacuum phase, the balloon 64 expands quickly into the condition shown in Fig. 5 wherein the nipple portion 94 may be seen to have moved upwardly a considerable distance thrusting the valve member 54 against the annular valve seat 37 surrounding the valve opening 36.As can be seen from Fig. 5, a large portion of the inner upper surface of the flexible resilient base portion 54 of the valve engages the valve seat 37 to form an excellent seal. Note also that the valve seat 37 has a concave configuration or curves inward¬ ly towards the interior of the container and that the valve member conforms to the valve seat surface. UREO PI W1PO The exact point of closure of' the valve is not criti¬ cal but the valve will typically close in the area indicated by the point 110 on the pressure curve in Fig. 8.It should be noted from Fig. 5 that the balloon member 64 is constructed to insure its expansion into the configuration illustrated. This is, the outer edge walls of the member 64 are somewhat thicker than some of the adjacent portions so that the balloon does not expand adially. Also, the upper wall of the member 64 includes a thickened annular rib portion which causes the balloon to take the general configur¬ ation illustrated which insures that adequate upward thrust of the valve closing member is obtained.It should also be noted that sufficient thrust is required to force the lugs 60a on the valve core 56 through the opening 36. The purpose for these lugs in addition to initially.properly positioning the valve is to make sure that the valve does not close prematurely due to a temporary drop in the pressure of the steaming cycle. That is, it has been found that some autoclaves have a considerable pressure variation as the steam is fed through the unit. Thus, a drop in pressure in the middle of the steam phase could cause the valve to close. However, the presence of the lugs 60 requires a sufficient force that normal variations in the steam pressure will not close the valve. About a 10 psi pressure drop is required to close the valve.Although the container is now closed by virtue of the valve 54 and the gasket 16, recall that the lid 12 was initially only loosely positioned on the base. Thus, as the pressure drops during phases P3 and P4 of the pressure cycle, a pressure differential between the interior and the exterior of the container is initiated. However, a unique quality of the gasket is that it will permit leakage out of the container with a relatively small pressure differential. Consequently, the steam that was within the container when the valve closed is still withdrawn from the container by the vacuum cycle. This is highly desirable because it means that the contents of the container are left in a dry and ster- ile condition. Thus, even at the bottom of the vacuum cycle, the lid 12 is still only loosely positioned on the gasket 16. Nevertheless, the flexible resilient nature of the gasket is such that gas cannot flow into the container. Thus, the gasket during this phase of the cycle essentially acts like a check valve.When external filtered air is introduced into the autoclave allowing the pressure the return to ambient, the vacuum which was applied to the auto- clave still remains within the container, as indicated by the dotted line PC. The gasket 16 and the valve 54- prevent this external air from entering the container. Although such air is filtered it is nevertheless not sterilized and hence, it is import- ant that this air not enter the container to'best maintain sterility.Since the incoming air cannot enter the container, the pressure of this air quickly forces the lid downwardly into its maximum closed position with the lid flange 22 tightly pressed against the gasket 16 so as to more positively prevent external air ' from entering the container. Similarly, the exterior air presses against the valve member 54 causing it to remain tightly seated on the valve seat 37 as illustrated in Fig. 6.Referring again to Fig. 8, the temperature in the autoclave also drops rapidly once the steam- BVTREOM, Λ. W1P ing cycle is interrupted, but 'then remains at an elevated level and slightly rises during the final vacuum phase, since the autoclave is heated. When the container is removed from the autoclave, the temperature gradually returns to normal. The reduction in temperature within the autoclave and later outside the autoclave eventually also cools the steam within the balloon chamber 66 causing a reduction in pressure within the chamber 66. This causes 'the resilient balloon member 64 to contract and revert to a position close to that it originally assumed, as illustrated in Fig. 6. The valve member 54 is of course no longer supported by the balloon 64 in that the ambient pressure is tightly holding the valve in position without any other support. This force is so strong that the weight of the inflatable chamber members 64 and 70 is of no consequence with respect to the seal produced by the valve, but usually the enla-rgement of the valve recess 55 results in the members following and returning to the position shown in Fig. 6. However, if the friction between the nipple 94 and the tubular, recess 55 is sufficient, the valve closing member will be lifted from its seat resting on the support wall 44. The valve closing member may remain in either of these two positions or it may be withdrawn or recycled for an additional use. It can of course, not be reused unless the plug 70 is withdrawn from the flexible member 64 and the heat shrink band 92 removed so that the valve opening 88 once more permits communication between the chamber 66 and the exterior. By providing a new heat shrink band 92, the valve ^ closing member can be reused. Normally, such recycling will be performed by people other than those using the container. Note from Fig. 6 that thfe heat shrink band 96 has shrunk tightly onto the nipple 94 because of the high temperature steam. This band 96 is - colored differently from the nipple 94 to provide an indication to the user of the container that the valve moving member has been used. Thus, this indicator band should be removed when the internal heat shrink valve element is replaced. A new indicator band should be loosely positioned over* the nipple when it is inserted in a valve..which is to be reused.With the valve member closing the opening in the end of the container, the contents of the container may be maintained in sterile condition for a long period of time. So long as the valve is in the position shown in Fig. 6, an observer will know that the contents are still sterile. If the vacuum within the container should be lost, the valve will withdraw slightly from the tightly sealed position due to the weight of the valve and its memory. This will tell the observer that the contents may no longer be of maximum sterility. However, the lugs 60 on the valve core 56 continue to hold the valve in the sealed position shown inFig. 7. While such seal has permitted some air to . enter the container as the vacuum was lost, the contents still have a minimum amount of contamination, and it is much less than that which relatively quickly results with present day methods of wrapping items to be sterilized and stored in towels.When the container is to be opened and the valve is still tightly sealed as shown in Fig. 6, the valve member may be readily removed by*pulling on the tab 62 attached to the valve member. As mentioned above, the valve member can be reused if desired, assuming it has not been held in a valve closed-BURE OMP position so long that the material no longer has adequate resiliency to maintain its original shape. The container cover may then be removed, although it may still be somewhat tightly in position even though the vacuum has been removed. To facilitate removal of the cover, the base may be held with one hand and the cover lifted by means of the tab 24 located on one end of the cover.Normally, the container will have been removed from a storage location into the operating area before it is opened.. When the cover is removed, there is a possibility that some dust or other contamination that may have accumulated on the exterior of the cover during storage could drop into the container interior. It is for this reason that the additional barrier layer of flexible plastic 102 was installed over the instruments prior to the sterilizing operation. This barrier layer can now be carefully removed by grasping one end and withdrawing it over one edge of the container so that hopefully any dust that may have fallen into the container will be removed with the barrier layer, or at least such dust will not fall directly onto the sterile instruments. Gravity Autoclave Operation While a vacuum autoclave sterilizing cycle is preferable from a standpoint of sterility and from a standpoint of best operation of this container, a large number of gravity autoclaves are still employed and the valve and valve closing assembly 40 of this invention can accommodate such cycle as well. Referring to Fig. 9 it may be seen that there are no vacuum cycles applied but instead high pressure steam is simply applied and then with¬ drawn. The valve and valve closing assembly 40 is used in the same manner as described above in connection with the vacuum cycle. The valve member 54 is closed at approximately the same location 110 on the pressure curve. Also, as the pressure is exhausted from the autoclave, pressure is exhausted from the container past the gasket in the same manner as described above. However, the only means for creating a vacuum within the container which will draw the lid more tightly into closed position and will hold the valve member 54 in tightly sealed condition is that vacuum which is created as the temperature of the small amount of residual steam within the container drops. The vacuum created in the container will follow a line more proportional to the temperature curve indicated at Tl in Fig. 9. Thus, for a period of time, there may be insufficient pressure differential to hold the valve member 54 in the tightly sealed position shown in Fig. .6. Instead, it may temporarily drop to the position shown in Fig. 7 wherein the lugs 60 retain the valve member in a sealing condition which prevents air leakage into the container. Note that the outer periphery of the valve member is oriented to properly engage the valve seat in that condition to prevent leakage into the container.As the temperature of the residual steam within the container drops further, an adequate pressure differential is created which will force the valve member back into the tightly sealed condition of Fig. 6. Also, it will pull the lid tightly into a sealed position on the gasket 16. The pressure within the container is indicated by the dotted line PC in Fig. 9. It should be appreciated that a relatively high vacuum is obtained even with the gravity type autoclaveOMPI simply due to the pressure drbp which is created as the residual steam condenses. While it is desirable that the contents of the container be completely dry, a small amount of sterile water, such as a few drops within the container does not present a significant problem.However, to keep such moisture away from the items in the container, a small amount of dessicant or other moisture absorbing material may be positioned in the container, with suitable means to isolate the dessicant until the end of the cycle. Such an arrangement is shown in Fig. 10 which illustrates an expandable balloon member 264 which is identical to the member 64 in Fig. 4 except that the upper wall 265 has a breakable or rupturable portion 267 which is much thinner than the adjacent wall thickness. The chamber within the member 264 is filled, with dessicant which is exposed to the interior of the container at the appropriate time to absorb residual moisture. In use, the inflatable member 264 is filled with a suitable dry dessicant 268 in granule form, which leaves a quantity of air in the chamber surrounding the granules. A plug 70 carrying a heat shrink band 92 like that shown in Fig. 4 is then inserted in the lower wall of the inflatable member 264 in the manner discussed above. The unit is then heated in an oven to sterilize the dessicant and to sterilize the interior of the inflatable member 264. During this heating process, the heat shrink tube 92 will shrink and close the valve opening leading to the interior of the inflat¬ able member 264, capturing a small volume of air that was in the oven. The proper time for sterilization t a given temperature is allowed. The member is then cooled and in effect becomes a small dessicant bomb which will rupture under the proper pressure-BUREATTOMPI conditions.When the container 10 of Fig. 1 is to be used in a gravity autoclave, one of the sealed member 264 filled with dessicant 269 is placed into the container along with the items to be sterilized. When the sterilizing environment is applied to the container, it can not enter the dessicant bomb 269 because it is sealed. However, at the end of the sterilizing cycle, when a vacuum is quickly created in the container as the residual steam in the container is cooled and condenses, the pressure is not reduced as quickly within the member 264 because the air in the member remains gaseous. Consequently, the member inflates or expands as the surrounding pressure within the container falls and the thin wall section 265 will rupture exposing the dessicant to the interior of the container. Another aspect of using the container in a gravity autoclave is that the container is initially filled with unsterilized air when it is placed in the autoclave. When steam is applied, it mixes with the air and sterilizes it. However, there is some possibility that a pocket of air may be trapped within the container near the end of the container opposite from the valve opening in that the air is heavier than the steam and circulation may not be complete simply by having the valve open. Thus, as a further assist to adequate circulation, there is shown in Fig. 11 the end of the container opposite the valve assembly wherein a heat responsive fuse-like element 270 is shown holding the lid 12 spaced slightly from the base 14. The element 270 is inserted in a hole in the lid tab 24 with an interference fit in a manner to be axially fixed and supported by the lid. A horizontally extending stop 272 on the element 270 and the lower end of the element 270 engage the side wall of the base to hold the lid in the spaced position shown. The element 270 is made of a material which will soften after being subjected to the high temperature steam for a predetermined period of time. Thus, the lid is partially open when steam is first applied with the result that the steam can circulate beneath the lid into- the container displacing the air in the container out through the open valve in the bottom of the container. When the element 270 softens, the lid simply falls into its initially closed position as discussed above in connection with Fig. 2; and the remainder of the cycle is as previously discussed. Other similar fuse-like arrangements may be employed for temporarily holding the lid ajar.Figures 12 and 13 Figs. 12 and 13 illustrate an alternate embodiment of the valve and valve closure mechanism as used in an identical container. Referring to Fig. 12 there is shown a valve and valve closure assembly 140 which includes a valve 152 having a saucer shaped base 154 and a centrally located upwardly extending core or stem 156 having a conical tip 157. Like the valve 52, the core 156 is provided with three ribs 158 having radially extending lugs 160. A tab 162 is formed integral with the base 154 for removing the valve from the valve opening 36.Also formed integral with the valve base 154 is a cylindrical portion which forms a piston 164. This piston is slidably positioned within a cup shaped member 165 defining a variable or expandable chamber 166 in cooperation with the piston 164. An annular bead 164a on the lower end of the piston engages the walls of the cylinder 165 to form a piston ring. The cup shaped cylinder has a centrally located inwardly extending portion 170 which limits the movement of the piston 164 into the cylinder 165. One or more valve openings 182 place the chamber 166 in fluid communication with the exterior of the chamber. Surrounding the central portion 170 and the valve openings 182 is a heat shrink band 192 similar to that shown in Fig. 4. As seen in Fig. 12, the band is spaced from the valve openings 182 so that fluid communication into the chamber 166 is maintained.In operation, the assembly 140 functions essen¬ tially like the assembly 40 previously described. The heat band 192 shrinks at a predetermined temperature level indicated at point 106 on the curves in Figs. 8 and 9. Thus, a quantity of high temperature, high pressure steam is captured within the chamber 166. When the pressure drops within the autoclave, the captured steam in the chamber 166 expands and reacts against the piston 164, forcing it upwardly and outwardly so that the valve 154 is sealed on the valve seat 37 as shown in- Fig. 13. As the vacuum is created in the container in the manner discussed above in connection with the two sterilizing cycles, the resulting pressure differential will hold the valve in the seated position shown, in Fig. 13.With the arrangement of Fig. 13 it is intended that the cylinder 165 remain with the container in the position shown. When the container contents are to be used, the valve 152 may be removed in the same manner as the valve 52 namely by pulling on the tab 162. It should be understood that with either expandable chamber mechanism, a simple check valve is staisfactory for capturing steam in the-BUROM _Λ. 1 chamber means for use in a gravity autoclave. Such a valve will permit flow into the expandable chamber but not out. The temperature responsive valve is employed so that in a vacuum autoclave cycle, the chamber does not expand during either of the initial vacuum cycles. The heat shrink bands 92 and 192 actually function as check valves after they initially shrink in that the material is rubber-like at that time. However, when the material later cools, it becomes permanently rigid.Description of Figs. 14 - 16 The preferred form of the container 300 illustrated in Fig. 14 includes an upper somewhat dome-shaped portion or lid 312 having an upper wall 312a and depending side walls 312b. The lower portion of the side walls 312b flare outwardly and downwardly forming a flange 312c which mates with the base 314 to form a closed container. As may be seen, the base 314 includes a bottom wall 314a which is generally flat, but the central portion of the wall is raised and slopes outwardly to a peripheral groove portion 314b. As can be seen from Fig. 15, the groove portion 134b includes an upper inner generally vertical wall 314c which extends downwardly from the periphery of the bottom wall 314a. The wall 314c is formed integral with a generally horizontal flange 314d which in turn joins with a U-shaped lower portion 314e. The outer portion 314f of the U-shaped portion 314e extends upwardly and outwardly to about the level of the periphery of the bottom wall portion 314a. A plurality of drainage holes are formed in the bottom of the U-shaped portion 314a, one of such holes 316 being shown . in Fig. 15.The container base 314 is also provided with a pair of handles 318 connected to the groove wall portion 314f. Located on one side of the container base is an upstanding wall or support 320 attached to the outer upper portion 314f of the U-shaped groove 314b. A cylindrical actuator housing 322 with snap-on cover 323 is connected to the support 320 by suitable means. In the bottom wall 314a of the base there are provided a plurality of upstanding hollow projections 324 aligned with a mating set of projections 326 formed on the lid 312. These projections facilitate stacking of a series of containers in storage. Positioned immediately above the base 314 in the illustration of Fig. 14 is a basket 330 having a bottom wall shaped and sloped to fit the bottom wall 314a of the base 314. The basket 330 also includes a series of projections 332 which mate with the projections 324. A plurality of holes 334 permit condensate to drain from the basket. Positioned immediately above the basket 330 is a cover or lid 336 which mates with the periphery of the basket 330.Also mounted on the base 314 is a resilient gasket 338 which cooperates with the lid and the base to seal the container. As may be seen from Fig. 15, the gasket includes an inner generally vertical sur¬ face that tightly engages the wall 314c on the base, while the lower edge of the gasket engages the flange 314d in the base groove. The gasket 338 includes an outer flexible flange-like portion 338a which engages the lid and deforms to provide a sealing surface, as may be seen in Fig. 16.Within the actuator housing 332 is positioned a lid holding actuator mechanism 340 which includes a balloon-like member 342 comparable to the member 364 shown in Figs. 4 and 5. The outer end wall 342a of the member 342 includes a centrally located- REOMP thickened throat 342b which defines a circular open¬ ing into the chamber 343. A' ring-shaped plug-like element 346 including an outwardly extending flange- like portion 348, having an outwardly facing groove, snaps within the throat in the wall 342a. While the element 346 closes the chamber 343, there is further provided a retaining ring 350, which surrounds the exterior of the throat holding it in tight en- gagement-with the groove in the flange 348.The actuator mechanism 340 further includes a hollow pin 344 having one end 344a secured to the interior of the plug 346 and a central portion extending through the member 340, out an opening in a throat portion 342c in the other end 344d of the balloon, and through a-hole in the support wall 320. The other end 344b of the pin 344 extends into the path of the lid 312 as it is opened and closed. In Pig. 15, the lid is shown being supported on the pin 344 which is supported by the support wall 320. The pin and the support wall 320 are sufficiently rigid to support the lid in cantilever fashion, as shown. The pin, of course, also supports. the balloon-like member 342. The pin end 344a secured to the plug member 346 is open, and thus defines a passage leading to a hole 352 in the wall of the' pin that opens to the interior chamber 343. Thus, the chamber 343 is in fluid communication with the exterior of the balloon 342. A thin ring or band 354 surrounds the tube 344 and extends over the opening 352 to serve as a.valve. The band 354, like the band 392 in Fig. 4, is made of heat-shrinkable material which, is initially flexible and which shrinks at a pre- determined temperature, and then becomes rigid when the temperature is lowered.gUREA£T OMPI- IP0 - ' Operation of Embodiment of frigs. 14 - 16In use, the surgical instruments or other items to be sterilized are placed within the basket 330, with the cover 336 on the basket. The basket is then positioned on the base 314, and the lid 312 placed onto the base with one edge of the lid supported by the pin 344 of the actuating mechanism 340, as shown in Fig. 15. The other side of the lid is, of course, positioned in the groove 314b of the base engaging the gasket 338. The entire container is then lifted by the handles and placed in an autoclave or other sterilizer to be subjected to a sterilizing cycle. The operation of the actuator mechanism 340 is similar to the valve closing means described above in connection with Figs. 1 - 7, when subjected to sterilizing cycles like that shown in either Figs. 8 and 9. When high-pressure steam is applied to the container, it enters the container beneath the open lid to perform the desired sterilizing function. If any steam is condensed, in striking the colder items in the container, it will flow off the bottom wall 314 towards the gasket 338 and the groove 314b, where it can escape through the drainage holes 316. The high pressure steam also enters the expandable chamber 343 by way of the hollow pin 344 and the valve opening 352. The temperature of the steam will cause the valve element 354 to shrink, closing the opening 352 and capturing a quantity of high-pressure, high- temperature steam within the expandable chamber 343. The steaming phase of the autoclave cycle can continue for whatever duration is desired and the pin 344 will continue to hold the lid 312 ajar, thus assuring that condensate can drain from the container.OMPI When the steaming phase is over and the steam is allowed to escape from the autoclave, the resulting pressure drop within the autoclave causes 5 the steam captured within the chamber 343 to expand * . the balloon into the shape or condition shown in Fig. 16. As may be seen, the inner end of the throat 342c of the member 342 engages the support 320. Consequently, when the balloon expands', the 0 only direction which it can move is to urge its outer end 342a together with the plug 346, outwardly away from the container lid. Since the pin 344 is secured to the member 346, the expansion of the chamber retracts or withdraws the pin 344 5 from beneath the lid 312, thus permitting the lid to fall into sealing position on the gasket 338 as shown in Fig. 16. The pin 344 is withdrawn partially into the chamber 343, although as can be seen, the tip of the pin end 344b remains in the support 0 wall 320 to provide support for the actuator mechanism 340. The pin 344 and the member 342 are, of course, constructed to permit the sliding movement of the pin within the member 342 without leakage of the steam from the chamber. Thus, the 5 container will close at approximately the same location on the curves in Figs. 8 and 9 that the valve will close in the embodiment of Figs. 1 - 7. That is, the lid will fall as the pressure is falling within the autoclave. 0 Also, as in the other arrangement, the gasket 338 will permit vapor to escape from the container if the pressure on the exterior of the container is further reduced, but it will prevent fluid flow from entering the container. When the 5 autoclave is opened and the pressure returns to normal, the lid is tightly kept on the base as the vacuum in the container. The container can be stored in this sterile condition for an extended duration.When the container is to be opened, a relief valve 360 in the top of the lid 312 may be pulled open to equalize the pressure inside the container with that surrounding the container, thus, enabling the lid to be lifted. Normally, the container will be carried into the room where the contents of the container are to be used. Thus, if the container is filled with surgical instruments, it would be carried into the operating room. The lid would then be removed and the basket 330 would be lifted from the container together with the cover 336 and carried to the sterile operating area. The purpose for the cover 336 is to prevent the possibility of dust or other unsterile material from falling from the lid 312 into the basket 330 when the lid is being removed from the container. The sterile cover 336 is then removed and the sterile instruments removed as needed during the operation.When the container is to be reused, it is a simple matter to remove the cap 323 from the actuator housing 322 and replace the actuator mechanism 340 with one having a heat-shrink valve 360 which is not yet shrunk on the tube 344.Embodiment of Figs. 17 - 22 Figs. 17 - 22 disclose a portion of a container similar to that shown in Fig. 14 incorporating a different lid holding a release mechanism. A lever 422 is pivotally mounted on the exterior side of a supporting wall 420 connected to a container base 414. More specifically, there is a generally vertically extending pivot pin 324 mounted on the wall 420, and the lever 422 has a pair of lugs 422a receiving the pivot pin 422. The lever is preferably made of a suitable, rigid plastic material similar to the container material. On one end 422b of the lever 422 is. formed a hinged flange 5 428 which extends above the support wall 420. On - - the other end 422c of the lever there is mounted a pin 430 which extends through a hole in the support wall 420. Surrounding the pin 430 is a coil spring 432 with one end of the spring engaging the outer 0 surface of the support wall 420 and the other end of the spring engaging the lever. Consequently, the spring urges the lever into the position shown in Figs. 17 and 18 with the flanged end of the lever supporting the lid 412. At the same time, the 5 pin 430 is out of the path of the lid. Note also from Fig. 18 that the hinged flange is somewhat higher than the pin.Extending between the lever and the exterior of the support wall 420 is an inflatable chamber 0 actuator 440, similar to that shown in Fig. 15 but without the pin 344 or similar to the expandable chamber 64 shown in Figs. 4 and 5. The actuator 440 may be supported by either the lever 422 or the wall 420, or by both. In the arrangement shown, 5 the plug 446 is made of two parts, one part 446a extending through a hole in the lever, and an outer cap 446b threaded onto the part 446a to mount the actuator on the lever.Operation of Embodiment of Figs. 17 - 22 0 n use, the container is positioned in a vacuum- type autoclave with the lid 412 supported on the flange end of the lever as shown in Figs. 17 and 18. When steam is applied to the container, the temperature responsive valve (not shown in Fig. 17) within the 5 actuator 440 will close, capturing a quantity of high-pressure steam. When the steaming phase is over and the pressure is allowed to drop within the autoclave, the captured steam.within the inflatable chamber will expand and pivot the lever against the urging of the coil spring into the position shown in Fig. 19. This movement' of the lever withdraws the flanged end of the lever from beneath the edge of the lid as shown in Fig. 20. Thus, the lid starts to fail towards the base. However, the pivoting of the lever which withdraws the flanged end of the lever has moved the pin 430, attached to the other end of the lever into the path of the lid so that the pin supports the lid, as shown in Fig. 20. Note that the lid is still spaced from the gasket 438 so that the container is still not yet closed and no pressure differential is created between the inside and the outside of the container. This, of course, is similar to that in the arrangements of Fig. 1 - 7 and 14 - 16 in that the gaskets act as on^-way valves when the lid is positioned on the base. However, at the maximum vacuum point.in the vacuum cycle the lid is still open; and hence, when the pressure in the autoclave is allowed to increase, the container pressure can rise also. This is in contrast to the 'earlier arrangements.As the pressure surrounding the- expandable chamber icreases, the. chamber will contract closer to its original shape 'as shown in Fig. 21. Thus, the spring returns the lever to the position shown in Fig. 21. This movement retracts the pin from its lid holding position and, at a predetermined point, allows the lid to fall into closed position on the gasket 438, as shown in Fig. 22. The movement of the lever pivots the flanged end of the lever towards the lid; but since that end is hinged and the lid wall is sloped, the end of the flange 428 simply flips up harmlessly as shown in Fig. 22. Alternatively, the slope of the lid and the exact configuration of the flange may be arranged such that the flanged end does not interfere 5 with the lid so that the hinging arrangement is; - not needed.Thus, with the arrangement of Fig. 17 - 22, the lid may be closed somewhere between the maximum vacuum point shown in Fig. 8 and the ambient 0 pressure line 104. The exact location may be precisely determined and easily modified in selecting the length of the retaining pin. For example, the pin may be threadably mounted in the lever and adjusted inwardly or outwardly. In 5 otherwords, the extent of the vacuum within the closed container may be easily controlled, and this in turn will determine the necessary strength of the container walls.. Thinner walls of course require less plastic and hence, are less expensive. 0 As explained above, such an arrangement is practical if the air being introduced into the autoclave to equalize the pressure is suitably filtered so as to be sterile. While present autoclaves do not provide this, future ones may. | CLAIMS 381. Apparatus for containing articles while being sterilized or stored, comprising means forming a closed container, means providing access to the • interior of said container and movable between a closed position and an open position, characterized by including: pressure responsive means responsive to the environment applied to said container; and means supporting said pressure responsive means on said container in a manner to control the position of said access means.2. The apparatus of Claim 1 wherein said pressure responsive means includes temperature responsive means for permitting operation of said pressure responsive means after a predetermined temperature of said environment is reached.3. The apparatus of Claims 1 or 2 wherein said pressure responsive means includes an expandable chamber which is initially open to the environment applied to said container, said chamber being arranged to close or release said access means when the chamber is in a predetermined position.4. The apparatus of Claim 3 further characterized by means including a valve which permits the flow of a steam environment into said chamber until a pre¬ determined temperature is reached, at which time said. temperature responsive valve means closes, capturing a volume of steam within the chamber, which is utilized to provide a force upon a reduction in pressure surrounding the chamber.5. The apparatus of Claims 1 or 2 further characterized by said container including a base and a lid with a gasket between the base and the lid providing a hermetic seal, said lid, base and gasket being arranged such that a decrease in the pressure within the container relative to the pressure • outside of the container when said valve is closed will draw said lid more tightly closed on said base.OMP 6. The apparatus of Claim 1 or 2 further characterized by said access means when open being arranged to permit condensed steam to drain from5. the container.7. The apparatus of Claim 1 further characterized by said access means including a valve opening in a wall of said container and a valve member supported on the exterior of the container adjacent said 0 opening and said container includes means for supporting said pressure responsive means adjacent said valve opening and in position to support and move said valve member.8. The apparatus of Claim 7 further characterized 5 by said pressure responsive means including an expandable chamber which is initially open to said environment and said temperature responsive means includes a valve which closes said chamber at a predetermined temperature, rendering said chamber 0 responsive to surrounding pressure changes, said chamber being arranged to support said valve member and move said valve member into said valve opening in response to said dropping gaseous pressure.9. The apparatus of Claim 4 or 8 further 5 characterized by said temperature responsive means including an inlet tube extending through a wall of said chamber, said temperature responsive valve including a hole in said tube which opens said chamber to its exterior, and including a band loosely 0 surrounding said tube over said hole, said band being heat shrinkable to close said hole at a predetermined temperature thereby closing said chamber.5 10. The apparatus of Cl-aim 7 further characterized by said valve member including a central stem which extends through the valve opening in the container and a flexible base portion attached to said stem which engages the surface surrounding said opening to close said valve, the central exterior portion of said base having a recess which extends into said valve stem, said expandable chamber comprises a generally hollow disc shaped balloon having a centrally located nipple which extends into the recess of said valve, said balloon having a base which cooperates with structure on said container for supporting the balloon and the valve means in proper alignment with said valve ■ opening.11. The apparatus of Claim 1 further characterized by said pressure responsive means including means holding said access means in an open position.12. The apparatus of Claim 11 further characterized by said pressure responsive means including expandable chamber means for capturing a quantity of a sterilizing environment applied to said container, said chamber means with its captured environment being responsive to the subsequent environment applied to said container for moving said holding means to release said access means and allow the access means to close at a • predetermined time.13. The apparatus of Claim 12 further characterized by said means for capturing a quantity of environment within said chamber means including valve means responsive to the temperature of said environment.14. The apparatus of Claim 12 further characterized by said container including a base and a lid, said lid forming said access means, said holding means comprises a pin mounted on said supporting means and holding said lid in the open- position, said expandable chamber means being connected to said pin to react against said supporting means to withdraw said pin from supporting said lid at a predetermined point.W1P 15. The apparatus of Ciaim 14 further characterized by said pin being attached to one end of said expandable chamber means, extending through said chamber means and slidably through an opening in the opposite end of said chamber means, and said opposite end of said chamber means being confined against a surface of said container so that when the chamber means expands, said one end of said chamber means moves, withdrawing said pin further into the chamber means and thereby withdrawing the pin from its position holding said access means.16. The apparatus of Claim 1, further characterized by said container comprising a generally flat base and a lid including a top wall and side walls which cooperate with the periphery of said base to form the container, said base further including an upwardly extending portion formed on its periphery positioned outwardly from said lid and forming said supporting means; and said pressure responsive means comprising an actuator mechanism including a holding pin supported through a hole in said base portion and extending into the path followed by said lid when the lid is moved into its closed position on the base, said pin being located to hold one side of the lid spaced from the base, said actuator mechanism further including means forming an expandable chamber having a pair of opposing end walls with one of said end walls having an opening therein slidably receiving said pin into the interior of the expandable chamber, said one end wa l being positioned adjacent said base portion, said pin being secured to the other end of said expandable chamber so that when the chamber expands, said other end of the chamber moves outwardly away from said base portion withdrawing said pin from its position holding the lid away from the base and thus allowing the lid to fall into closed position on said base. 17. Apparatus of Claim '16 further characterized by: said pin having an opening therethrough that places the interior of the chamber in communication with the exterior of the chamber so that when a sterilizing environment, such as steam, is applied to the exterior of the container, and the expandable chamber, it is also applied to the interior of the expandable chamber; and further including valve means responsive to said environment for automatically closing said opening leading into the interior of the expandable chamber to thereby capture a quantity of the sterilizing environment within the expandable chamber.18. The apparatus of Claim 17 further characterized by said valve means being temperature responsive to close when subjected to steam to thereby capture a quantity of steam within the expandable chamber, said expandable chamber being constructed such that when a quantity of high-pressure steam is captured within the chamber and the pressure surrounding the chamber is reduced, the chamber will expand to cause the actuator pin to be retracted.19. The apparatus of Claim 1 further characterized by said environment including a pressurized steam phase followed by a final vacuum, and said pressure responsive means including: means holding said access means open so that when the container is subjected to said steam phase steam can enter the container; and means for automatically closing said access means at a predetermined point in the sterilizing cycle after the maximum vacuum point has been reached in the final vacuum phase of the cycle but before the pressure has returned to ambient pressure. 20. The apparatus of Ciaim 19 further characterized by pressure responsive means including an expandable chamber in which is captured a quantity of the steam5 applied to said container, and said closing means • _ further includes holding elements moved by forces produced by said chamber in response to changing pressures applied to the exterior of the chamber.21. The apparatus of Claim 20 wherein said 0 pressure responsive means further includes a temperature responsive valve which is initially open but closes in response to steam temperature, that controls flow of steam into said chamber.22. An actuator mechanism for providing an 5 actuating movement responsive to changes in gaseous pressure in the environment surrounding the actuator means, characterized by including: an expandable chamber which is initially open to said environment, and temperature responsive 0 means which automatically closes said chamber at a predetermined temperature, capturing a volume of said environment in the chamber and thus rendering the chamber responsive to surrounding pressure changes so that the expansion and 5 contraction of the chamber may be used to provide an actuating force.23. A method of sterilizing and storing items comprising the steps of placing the items to be sterilized in a container, placing the container in 0 a sterilizer with the exterior of the container in fluid communication with the interior by way of access means to the interior of said container, and applying a sterilizing environment to the interior and exterior of the container, characterized by closing said 5 container access means, after the contents of the container have been sterilized but before the container is subjected to an unsterile environment by the use of ' means responsive to the pressure of the environment applied to the container.- υ REAir0MPI_ Λ> W1P0 ----V, 24. The method of Claim- 23 characterized by the access means being held open by said pressure responsive means and being allowed to close by gravity when released by said pressure responsive means.25. The method of Claim 23 further characterized by said access means being moved from an open position to a closed position by said pressure responsive means.26. The method of Claim 23 further characterized by said sterilizing environment being pressurized steam, and said pressure responsive means being responsive to the reduction of pressure occurring as said steam is withdrawn from the container.27. The method of Claim 26 further characterized by initiating the operation of said pressure responsive means by means responsive to the temperature of said steam.28. The method of Claim 27 further characterized by the container having a valve in one wall and said pressure responsive means including means defining an inflatable chamber which is positioned to move the valve into closed position when the chamber expands.29. The method of Claim 27 wherein said closing step prevents further flow into the container but flow out of the container is still permitted when pressure on the inside of the container is greater than on the outside.30. The method of Claim 23 further characterized by said pressure responsive means being an expandable chamber which produces a force for closing or releasing said access means.31. The method of Claim.30 further characterized by said expandable chamber being initially open and then closed to capture a volume of the sterilizing environment. 32. The method of Claim 31 further characterized by said sterilizing environment being pressurized steam and said chamber is closed by means responsive. to the steam temperature.33. ' method comprising applying a gaseous environment to an expandable chamber which is open to the environment, closing said chamber to capture a volume of the environment within the chamber, changing the pressure or temperature of the environment surrounding the chamber to change the pressure of said volume within the chamber, and employing the resulting change in the size of the chamber to provide an actuating movement characterized by the environment applied to said chamber being at an elevated temperature and said chamber being closed by means responsive to said elevated temperature.34. The method of Claim 33 further characterized by including the step of employing the motion produced by said expandable chamber to close a container used for holding and storing items to be sterilized, and wherein said environment is pressurized steam which is also applied to said container and its contents to sterilize said contents.. (Received by the International Bureau on 8 January 1979 (08.01.78))1. Apparatus for containing articles while being sterilized or stored, comprising means forming a closed container, means, providing access to the interior of said container and movable between a closed position and an open position, characterized by including: pressure responsive means for sensing a reducti in the pressure of a sterilizing environment applied to the exterior of said container; and means, supporting said pressure responsive means on said container in a manner to allow said access means to close or to move said access means to the closed position at a desired pressure.2. The. apparatus, of Claim 1 wherein said pressure responsive means includes temperature responsive means for permitting operation of said pressure responsive mean after a predetermined temperature of said environment is reached.3. The apparatus of Claims 1 or 2 wherein said pressure responsive means includes an expandable chamber which is initially open to the sterilizing environment applied to said container, said chamber being arranged to close or release said access means when the chamber is in a predetermined position. 4. The apparatus of Claim 3 further characterized by means including a valve which permits the flow of a steam environment into'said chamber until a predetermined temperature is reached, at which time said temperature responsive valve means closes, capturing a volume of steam within the chamber, which is utilized to provide a force upon a reduction in pressure surrounding the chamber.5. The apparatus of Claims 1 or 2 further characterized by said container including a base and a lid with a gasket between the base and the lid providing a hermetic s'eal, said lid, base and gasket being arranged such that a decrease, in the pressure within the container relative to the pressure outside of the container when said valve is closed will draw said lid more tightly closed on said base. STATEMENTUNDERARTICLE19The search results forwarded by letter mailed November 8, 1978 regarding the above-identified application have been reviewed. In accordance with article 19 (1) and Rule 46.1 concerning the Patent Cooperation Treaty provisions, please substitute the enclosed Page 38 for the Page 38 presently on file.JURE AirOMPI _ | SANDERSON R | SANDERSON R; WHELCHEL R |
WO-1979000082-A1 | 1,979,000,082 | WO | A1 | XX | 19,790,222 | 1,979 | 20,090,507 | new | B24B13 | B23B3 | B23B5, B24B13, B29C39, B29C61, B29C69, B29D11, G02C7 | B24B 13/00G, G02C 7/04 | METHOD AND APPARATUS ADAPTED FOR AUTOMATIC OR SEMI-AUTOMATIC FABRICATION OF ULTRA-PRECISION OPHTHALMIC LENSES,E.G.,CONTACT LENSES | A method for forming a plurality of optical surfaces on an optical lens precursor, desirably a soft contact lens button or blank, to yield a lens adapted for proximate or intimate contact with an eyeball and defined by at least one posterior surface, an edge and at least one anterior surface, is comprised of forming a precision lens precursor, assembling the precursor in a microsurface generating apparatus, ultra-precisely forming the curves or geometry comprising the posterior surface and a portion of the edge to yield a semi-finished lens, blocking the semi-finished lens on an adhesively coated lens block fixture having an ultra-precisely preformed face for intimate precision mating with the posterior surface of the semi-finished lens, reassembling the semi-finished lens/fixture in the microsurface generating apparatus, ultra-precisely forming the curves or geometry comprising the anterior surface and another portion of the edge, and demounting a finished, ultra-precision lens from the blocking fixture. Also disclosed is a fluid-bearing automatic or semi-automatic machine for performing the instant method to ultra-precision, e.g., by computer control. | METHOD AND APPARATUS ADAPTED FOR AUTOMATIC OR SEMI-AUTOMATIC FABRICATION OF ULTRA- PRECISION OPHTHALMIC LENSES, E.G., CONTACTLENSESBACKGROUND OF THE INVENTIONField of the Invention:The present invention relates, broadly, to a low microinch surface generator adapted, particularly, for the manufacture of plastic contact lenses. Most specifically, the present invention relates to method and apparatus for the fabrication of soft or hydrophilic contact lenses by precision machining a lens precursor (e.g., button, blank, or even bonnet) in the non-hydrated state. Description of the Prior Art:Numerous methods and apparatus are well known for the fabrication of optical surfaces on a variety of optically-efficient materials. Among these materials might be included various grades of glasses and plastics as well as, for reflective optical applications, metals.However, quantitatively, the manufacture of vision-corrective optical articles far outweighs the remaining areas of endeavor in this field. Surprisingly, therefore, it is found that few truly efficient methods and apparatus exist for the manufacture of vision-corrective optical articles; most approaches being rather pragmatic on an individual basis and possessed of anachronistic shortcomings.Perhaps the routine use of obsolescent technology is most encountered in the manufacture of contact lenses i . for the correction of vision defects, and including the manufacture of the new, soft or hydrophilic polymeric contact lenses. With the modern shift from eyeglasses to contact lenses, the first generation hard synthetic plastic or glass-type contact lenses were initially ; fabricated based upon mere industrially-acceptable and conventional techniques. Thus, the hard plastic [typically polymethyl ethacrylate or PMMA ] or glass lens precursors were formed in a rough state, ground, and subsequently polished either manually, or semimanually with the aid of conventionally employed optical polishing machines. Again, with the conversion from hard contact lenses to soft, hydrophilic lenses, antiquated methods and apparatus were perpetuated, notwithstanding the highly significant differing physical and chemical characteristics between these hydrophilic polymers and the materials for which the prior methods and apparatus were initially designed.One deviation in the manufacture of soft contact lenses emerged in the form of the spin casting of the hydrophilic monomer during the very polymerization process therefor. While clearly a departure from conventional optical machining and polishing, the spin casting technique was found to be but a basically acceptable compromise, required primarily by the very nature of the lens material. Thus, the compromise is regarded as- successful only inasmuch as the ease of process control has been fostered, but at the sufferance of optical quality and reproducibilit . This is due to the fact that the anterior surface of the finished lens is predicated upon the shape and quality . of the mold cavity, while that of the posterior surface is dictated by the centrifugal forces established during the spin casting process as the monomer polymerizes ,• viscosity, and the like. Because it is recognized that the surface of the eyeball is not uniform, but has a sub¬ stantially varying rate of curvature generally corresponding to the apical portion of prolate ellipsoids, paraboloids, and hyperboloids, the ability to properly fit a centri- fically cast hydrophilic contact lens with the optimum visual acuity is minimized. Moreover, even a centrif - gaily cast lens must be manually or otherwise edged. Accordingly, this technique has been found to be less than adequate in meeting the needs of the industry in properly balancing the ease of reproducibility and repeata¬ bility with the requirements of enhanced optical fit and power and, thus, wearer comfort and optical efficiency of the finished lens, particularly for those with astig¬ matic defects.The art has recognized the advisability of producing methods- and apparatus for machining or grinding the hydrophilic lens material in a non-swollen or dehydrated physical state. However, these approaches have not yielded a substantially improved finished lens for a number of reasons. Most significantly, the improvements in methods and apparatus heretofore proposed have merely centered about the modification of old technology, rather than an attempt to provide a totally new and improved system or concept which specifically accounts for the physical and chemical vagaries of the hydrophilic materials to be formed. Thus, it is routinely found that, for example, the tolerance limits of the machines employed far exceed those desirable tolerances for the finished product. Consequently, constant operator scrutiny and sub¬ sequent, costly rectifying procedures must be employed to yield a precision lens, or to otherwise salvage defective articles.Furthermore, the very nature of the materials employed in the fabrication of these soft lenses mandates a critical appraisal of current production techniques. For example, in addition to all of the exacting operating procedures necessarily employed in the manufacture of high quality optical articles, the machining of hydrophilic polymers in a non-swollen or anhydrous condition entails process control far beyond that necessary for theO analogous machining of glass or hard plastic lenses. For example, the hydration factor must be taken into account since the ultimate shape of the lens in the hydrated state may differ by 15%, or more, from that in the dehydrated state. This further complicates the handling of the lenses during the fabrication steps- since even a small amount of moisture, such as that on the tip of an operator's finger, or ambient humidity, can materially, locally swell the lens precursor. Consequently, should the operator touch the lens during the manufacture thereof, perspiration will cause local swelling which will ultimately be machined or polished away during further process steps. When the lens then dehydrates at the local position, an obvious, and oftentimes fatal, flaw results, thus rendering the lens unsuitable for its intended purpose. Yet other problems are encountered due to the nature of the physical and chemical characteristics and properties of soft contact lenses. For example, soft contact lenses not uncommonly have a greater diameter than the hard lens counterparts. Also not uncommonly, a soft lens extends well into the scleral area of the eyeball, thus transgressing the sensitive li bus. Moreover, due to the changing rate of curvature of not only the cornea but the scleral area, the optimum lens configuration will account for these differences and thus, be provided with a posterior surface which matches this changing rate of curvature of the cornea, jumps the limbus, and rests again on the sclera. And, while the scleral area is less sensitive than the cornea or limbus region, it is also essential that the edge radius of the lens be smooth and contoured to minimize eye irritation during wear. Also, while the posterior surface must account for the aspherical aberrations of the eyeball, the anterior surface must likewise be machined to very exacting tolerances, regardless of whether or not a plus or minus lens is to be yielded, to provide the required optical characteristics for the lens. To adequately account for the demanding designs inherent in quality optical contact lenses, it is thus essential to provide a maximum acceptable gross tolerance on the order of 0.001 inches, while optical surfaces should exhibit a finish of at least 4 microinches. Obviously, the greater the number of operating steps or points of human operator intervention, the less realistic become the attainment of these objectives.Various automated processes, and apparatus therefor, have been proposed in the prior art. For example, U. S. Patent No. 3,913,274 discloses a method and apparatus for making integrated multifocal lenses wherein a lens precursor is rotated in a lathe chuck and appropriately indexed in contact with a cutting tool or grinding wheel. The disclosed invention is predicated upon an adaptation of a conventional lathe whereby the lens is secured in a rotating spindle which also provides relative motion in two orthogonal directions in a plane perpendicular to the center of rotation of the lathe. The tool bit or grinding wheel is also caused to rotate about a variably controlled pivot point to allow for the cutting or grinding of different curvature radii of the multifocal lens. Appropriate translation of the cutting tool and rotating lens is achieved by means of a digital computer. While such apparatus are efficient for the manu¬ facture of relatively large lenses, their utility is diminished when the workpiece is reduced to the much smaller size of a contact lens. For example, the column which supports the lens precursor, and which is tilted relative to the rotational axis of the lathe spindle, is not suitable for use as a fixture for supporting and rotating the much smaller contact lens. Moreover, the need to provide substantial superstructure in order to achieve sufficient relative freedom of motion tends to decrease dimensional stability by increasing the number of sources which contribute to dimensional error. Also, it is obvious that significant operator intervention is needed in order to practice the disclosed process,-βl •- 6- further contributing to potential sources of dimensional instability and lack of reproducibility from lens to lens. Another apparatus is disclosed in United States ; Patent No. 3,835,588, relating to a lenticular contact lens lathe. Again, because t e apparatus is patterned on a standard contact lens lathe, which has been modified to provide for an orthogonal translation system via cascaded movable carriages, inherent dimensional instab- : ility is built within the system. Moreover, it is necessary to cast or otherwise preform the lens precursor with the posterior surface thereof. Consequently, the same disadvantages obtaining with the spin casting of hydro¬ philic monomers is indigenous to that disclosed process. Similar apparatus and processes are disclosed in the United States Patents No. 3,064,531 and No. 3,100,355, wherein the lens precursor must first be subjected to a substantial preforming operation in order to render the same compatible with a lathe chuck or other conventional securing member. In the case of the former patent, the lens precursor is threaded for insertion within a special chuck having a matting thread. . In the case of the latter, the precursor is first formed with a peripheral ear for restraint within a sleeve. Obviously, the preforming steps are highly undesirable. In an effort to minimize operator intervention by maximizing the number of process steps on a lens blank between mounting and demounting thereof, a quite mechani¬ cally exotic apparatus is disclosed in U. S. Patent No. 3,686,796. The machine therein described performs multiple operations, including machining, lapping, edging, and/or polishing a lens which is retained in a rotatable lens holder relatively indexable with respect to a plurality of pivotally mounted spindle heads, each for performing a given operation. Obviously, the complexity of such a machine and the need to provide the great number of• separate machine tools which must be accurately registered from step-to-step are highly undesirable from a commercial point of view. Conventional pantographs and cam followers have been adapted for fabricating contact lenses, but not without suffering many of the problems noted above and without providing the ability to produce high quality articles in reproducible, commercially-acceptable quantities. These deficiencies may be attributed to, for example, the complexity of mechanical linkage, inherent machine and ambient vibrations, the inability to produce an article of better quality than that of the pattern's surface, etc. Yet a further problem evident with prior art methods and apparatus for forming contact lenses is the inability of the same to yield 'an edge, as machined, without defects. Consequently, various, postforming polishing opera- tions such as those disclosed in U. S. Patents No. 3,032,936 and No. 3,736,115, are necessary. Again, by increasing the number of operations, potential additional sources of error are encountered.Accordingly, the need exists to provide a scienti- fically sound concept, method and apparatus for the repro¬ ducible, simple, and efficient manufacture of high quality optical surfaces on an optical le.nse precursor, whereby the number of process steps are minimized and which substan¬ tially diminishes the need for human intervention- SUMMARY OF THE INVENTIONIn accordance with the noted and notable deficiencies of prior art methods and apparatus for forming optical surfaces on a lens precursor, it is a primary object of the present invention to provide an automated or semi-automated method which materially increases productivity, reproducibility and efficiency while conco i- tantly reducing the cost of manufacture of the resulting lense.It is also an object of the present invention to provide an automated or semi-automated machine for prac¬ ticing the present invention.Yet another object of the present invention is to provide an automated or semi-automated machine which incorporates a fluid-bearing microinch surface generator BU for fabricating spectacle lenses and contact lenses, particularly contact lenses. Still a further object of the present invention .is to provide an automated or semi-automated apparatus comprising fluid-bearing X-Y positioning tables, in concert with a fluid-bearing work supporting spindle, for the simple, efficient, and economical manufacture of hydrophilic contact lenses, which are machined in their hard or non-hydrated state. Most preferably, such apparatus is computer controlled and electronically driven to produce a predetermined path of infinite resolution. Still further objects of the present invention will become apparent to the skilled artisan upon examina¬ tion of the detailed description of the invention, taken in conjunction with the Figures of Drawing.In consonance with the af renoted objects of the present invention, it has now been determined in accordance therewith that a plurality of optical surfaces may be formed on- an optically-efficient material through use of an automated or semi-automated machine which is comprised of a fluid-bearing tool positioning table in concert with a rotatable, fluid-bearing work supporting spindle, said spindle itself being mounted upon a secondary fluid-bearing positioning table situated perpendicular to the tool positioning table. Tool posi¬ tioning is appropriately indexed via computer control utilizing appropriate feedback system including, e.g., - linear or rotary encoders or laser interferometric methods, whereby any complex lens geometry may be easily and reproducibly fabricated.The automated or semi-automated method of the present invention comprises the steps of assembling a precision lens precursor to the work holding device of the spindle member, generating the appropriate lens geometry on a first face of the lens precursor, removing and blocking the semi-finished lens on a fixture therefor, indexing the semi-finished lens/fixture assembly to the spindle, generating the opposing lens surface geometry, and demount¬ ing a precision, optically finished lens from the blocking fixture.BREIF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective illustration of the microinch surface generating apparatus of the present invention, and its associated computer controller; Figure 2 is a flow diagram of the process of the present invention, and shows schematically the configuration of a lens as it is formed during this process; Figure 3 is a side elevational view of the lens blocking apparatus of the present invention;Figure 4 is a top plan view of the lens blocking apparatus of. the present invention;Figure 5 is an exploded, side, fragmentary view taken substantially along the line 5-5 of Figure 3; Figure 6 is an enlarged view of a finished contact lens; and,Figure 7 is an even more enlarged view of yet another finished contact lens formed according to the invention.DETAILED DESCRIPTION OF THE INVENTIONIn order to more fully elucidate upon the various objects and advantages of the present invention, the same will be described in terms of various preferred embodiments thereof. Further along these lines, the invention will be described in terms of the manufacture, of a hydrophilic contact lens. However, it will be appreciated that the same are intended as illustrative, and in no wise limitative. The present invention relates to the formation of optical and complementary surfaces on optically- efficient materials and, more particularly, to the fabrication of hydrophilic contact lenses. The present invention overcomes substantially all of the prior art deficiencies inherent in the use of antiquated methods and apparatus for the manufacture of, e.g., contact lenses and, more specifically, from hydrophilic polymeric materials. That is, the instant method and apparatus U minimizes operator handling, while maximizing process efficiency, strict repeatability and product quality. Currently, apart from the spin casting of hydrophilic contact lenses, small lathes with radius ':' turning attachments, primarily under manual control, are employed as standard production apparatus. And, while the Operators need not be skilled in the machinists' sense, they nonetheless require several weeks or months of training before becoming adept enough to generate lenses at a yield of more than, approximately, 25%. Moreover, whether it be attributed to operator skill and/or machine tolerance, accuracy and reproducibility are each quite low thus necessitating laborious hand polishing to obtain an acceptable finish. Also, the ability to cut curves having other than simple radii is minimized, if not precluded, in light of the foregoing limitations. In sum, the present state-of-the-art of contact lens manufacture is more art than science.Figure 1 illustrates, perspectively, a microinch surface generator, designated generally as 10, and an associated computer control therefor 12. Numeral 12a . designates the electronic interface cable linking the computer 12 to the generator 10. Microinch surface generator 10 is comprised of a fluid-bearing tool support Y-axis table or slide 14 and a fluid-bearing work support spindle motor designated generally as 16. Spindle 16 is itself fixedly mounted upon a second fluid-bearing X-axis positioning table or slide 14a which is disposed perpendicular to the axis of movement of the tool positioning table 14. Preferably, these fluid-bearing components are gas-bearing structures; most preferably, air-bearing. The table drives (axially reciprocating) are preferably comprised of electronically driven, com¬ puter controlled D. C. torque motors, to avert the roughness arising from the use of conventional stepper motors, and which motors are coupled to zero backlash lead screws. The table 14 supports a tool holder base 18, fixedly secured thereto, upon which is borne a tool positioning block 20. The tool positioning block 20 is adapted for axial reciprocation (not shown) along the Z axis, whether manually or otherwise, and advantageously is equipped with both radical and fine adjustments. A suit- able cutting tool 22 is firmly attached within the block 20. The tool 22 is, most preferably, an ultra-precision, angularly set, cylindrical diamond-tipped cutting tool, although it might be an ultra-precision rotary tool such as, e.g., a grinding wheel or burring tool. Regardless of the type of cutting tool employed, it is essential, and especially so with respect to the preferred diamond-tipped cutting tool, that the same present a substantially absolutely circular cutting surface to the workpiece of, e.g., non-hydrated hydrophilic polymer. Thus, in the pre- ferred embodiment, the diamond-tipped tool is provided with a circular cutting surface within a tolerance of 0.005 inches truth of circular profile, preferably within 0.0002 inches truth of circular profile, most preferably within 0.00005 inches truth of circular profile. In a most preferred embodiment of the invention, the Y-axis table or slide 14 supports a plurality of base/ block/tool modules, for example, a base 18/block 20/rough- ing cut tool 22 module and a base 18a/block 20a/fine cut tool 22a module fixedly spaced apart along a common Y- axis parallel 'to that of the table 14, and adapted such that after the roughing cut tool 22 has been electronical¬ ly indexed to the workpiece and done its work, the fine cut tool 22a can conveniently be electronically relocated in its place for the ultra-precision finishing. The work support spindle 16 terminates in a work holder, preferably an air collet 24, as viewed in Figure 2. The spindle/motor is fluidly rotatable about a horizontal axis, as is known to the art.By employing the fluid-bearing X-Y tables 14 and 14a, in concert with the computerized controller, any complex surface geometry may be generated, provided the mathematical function describing that geometry is- VTO unique in a given quadrant; i.e. , any curve which has only one Y for each value of X.. The tables are provided with substantial rigidity to avoid deflection under cutting loads, which is further aided by appropriate provisions :- for smoothness of operation and freedom from backlash. This is achieved, primarily, by employing a table bed of about 4,000 pounds, in a preferred embodiment by incor¬ porating a granite bed isolated from vibration.In a highly preferred embodiment, both the X and ' Y slides for tables 14 and 14a are air-bearing slides driven by fine pitch lead screws incorporating self- aligning nuts and D. C. servo motors. Position monitoring is achieved by electro-optical encoders with 0.5 micron resolution. A tachometer is in operative communication with the motors and the computer controller to enhance servo stability.The spindle 16 is likewise based upon an air- bearing slide to optimize the optical surface finish, as well as to ensure both isolation from vibration and tool life. The spindle motor can be present at any suitable value over the range of from about 1,000 to about 30,000 rpm, and is comprised of an integral drive motor. Radial and axial runout of the spindle/motor are maintained at no greater than 0.000010 inches T.I.R. In order to effect accurate pre-positioning between the tool 22 and the workpiece restrained within air collet 24, there are optionally provided a pair of closed circuit television cameras in two mutually orthogonal planes. A first optional camera, 30, in concert with a video display 32 allows the operator to view an enlarged picture of the tool 22 relative to a workpiece 34 in the horizontal plane. A second optional camera 30a is disposed 90° from camera 30, to the rear of the housing for microsurface generator 10, and operates in concert with optional video display 33 for allowing the operator to view an enlarged picture of the tool 22 relative to the workpiece 34 in a vertical plane. In a preferred optional embodiment, the cameras are Panasonic WV-ZOOP CCTV cameras for continuous monitoring of both vertical and horizontal positioning. The video display units are Panasonic No. WV-952 monitors. For contact lens manufacture, the image is optically magnified about 30 times. The X-Y, fluid-bearing tables 14 and 14a allow relative fluid movement of the tool 22 with respect to the spindle/motor 16 in two orthogonal directions, defining a horizontal X-Y plane. To facilitate tool set-up, the tool positioning block 20 in concert with base 18 provides Z translation of the tool 22 by appropriate operator . manipulation. Similarly as regards block 20a, base 18a ar tool 22a.Figures 3-5 illustrate a lens blocking machine, designated generally as 100, which is utilized in concert with the microsurface generator 10, and defines a necessary element of the overall system. The lens blocking machine 100 is comprised of a rotatable, generally circular table 102, although any of a number of geometries are conceivable. As best viewed in Figure 4, a plurality of rotatable lower spindle assemblies 104 are located equidistantly around the periphery of the table 102, four such assemblies being shown spaced 90° apart. Each of the assemblies 104 is comprised of a stationary base 106 and a rotatable spindle 108. A shaft 110 is in operative communication with spindle 108 for imparting any desired rotational movement thereto. Spindle 108 terminates in an air collet 112 for grasping a preformed lens block 114.The lens block 114, conventionally termed a pitch block in the art, is preferably fabricated from tool steel which is heat treated to exhibit a hardness of about 60 Rockwell/C scale to insure good service life, dimensional stability and minimize damage to the surface area for supporting a lens. The lens blocks are precision ground and lapped to a surface geometry and tolerance better than that prescribed for the inished lens, preferably better than by a factor of at least 4-5 times. Thus, there is provided a reusable lens block having both a high service factor along with the ability to very accurately establish precision datum reference points for -id- subsequent lens shaping. Moreover, the automated or semi- utomated machine of the present invention is parti¬ cularly designed for operation with a plurality of lens blocks which will undoubtedly be machined with varying - ' radii of curvature regarding the lens-supporting surf ce to account for varying lens geometries. Thus, it is further essential that strict uniformity of the overall dimensions of the lens blocks be maintained regardless . of differences in that supporting surface, in order to insure reproducibility in establishing a zero datum point for lens generation which insures maintenance of lens center thickness. To achieve this objective, the distance from the back banking surface 117 of the lens block, which locates the lens block in the holder (e.g., collet) , to the apex of the radius of the lens-supporting surface must be maintained uniform for all of the lens blocks utilized, within a tolerance limit of +0.001 inches, preferably +0.0005 inches, most preferably +0.0001 inches. Disposed adjacent, and projecting vertically above, the assembly 104 is an upper work supporting spindle -assembly designated generally as 120. Accordingly, each of the four positions illustrated may be viewed as having the appearance of a small bench press. The assembly 120 is comprised of a vertical support member 122 to which is appended an air actuated carriage 124 for vertical translation of a work supporting spindle 126. The spindle ' 125 terminates in an air collet 128 for receiving a semi¬ finished lens which is to be accurately positioned and secured to the lens block 114. Collet 126 may be displaced from an upper load configuration as shown in phantom lines in Figure 3 to a lower assembling configuration by means of the introduction of, for example, compressed gas at metered inlet 130 of gas piston 132. Retraction may be effected by providing reverse bias on the piston and allowing the gas to escape through a metered exit port . 133, or by the application of positive pressure through port 133.Accurate positioning between the collets 104 and 126 is achieved by causing the latter to translate vertically downwardly along a guide plate 134 borne upon support structure 122, the guide plate cooperating with a roller assembly 136. As best viewed in Figure 5, the upper spindle 126 is. further provided with a positioning plate 136 having a pair of apertures 138, which apertures are fitted with bushing members. Cooperating therewith are a pair of opposing guide pins 140 borne upon support plate 106, in association with the lower spindle assembly 104. Thus, as upper spindle 126 is caused to be downwardly displaced by actuation of air piston 132, the guide pins140 will accurately position the same relative to the lower rotatable spindle 108.Located proximate the spindle assembly 104 is an adhesive dispenser, designated generally as 150. Any of a number of suitable adhesives may be employed for affixing a lens to the lens block 114, the selection of an appropriate composition being well within the purview of the art. Dis¬ penser 150 is supported by members 152 secured to a base member 154 at a height whereby a reciprocable dispensing assembly 156 may be indexed to a positioning immediately above lower spindle assembly 104. Dispenser assembly 156 is comprised of a reservoir 158 for heating and containing the adhesive to be dispensed where heating is appropriate, and a dispensing orifice 160. Horizontal translation of the assembly is achieved by movement of a shaft 162 which is controlled, preferably, by an air actuated mechanism (not shown). The shaft 162 terminates in a head member 164, to which are fastened a pair of shafts 166 for guiding the reciprocable assembly 156 during the indexing thereof. Dispensing of adhesive under compression is effected by controlled admission through a fitting 170 and a conduit 172 in communication with suitable reservoir (not shown) into the dispensing head 158, and ultimately through dis¬ pensing orifice 160. Alternatively, as is also generally shown inFigure 2, the lens blocking machine may comprise a single spindle assembly.Figure 6 illustrates, in cross-section, a finished contact lens of greatly exaggerated dimensions in order to exemplify the plurality of optical surfaces comprising the lens structure. The lens of Figure 6 is defined as a posterior surface A, including the base curve, and an ' opposing anterior surface B, including the power curve, each of which is the composite of, optimally, a plurality of optical and complementary surfaces. For the ease of description, the lens of Figure 6 has been divided into ; major regions having an average radius of curvature denoted as r.; however, the ideal lens will very closely parallel the changing rate of curvature of an eyeball for maximum visual acuity and wearer comfort and will, thus, be comprised of literally hundreds of individual surfaces of varying radius. Indeed, the present invention is expressly directed to the generation of such aεpheric opti¬ cal surfaces, as well as the typically spherical power curves, or combination thereof, and wherein the various individual radii including those of the edge, exhibit a tolerance within 0.0004 inches, and preferably within 0.0001 inches. In other words, the posterior surface of the lens is precisely formed for correspondence with the changing rate of curvature of the eyeball by providing a surface comprised of a plurality of discrete optical surfaces with individual posterior radii, each of which is accurate, for correspondence with the eyeball, within a tolerance of 0.0004 inches, preferably of 0.0001 inches. Likewise, the anterior surface is precisely formed for optical resolution (when considered in concert with lens thickness, material, etc.) by similarly providing a surface comprised of discrete optical surfaces with individual anterior radii, each of which is accurate, for optical resolution, within a similar tolerance of 0.0005 inches, preferably of 0.0001 inches. A finished contact lens 200 in accordance with the invention is shown in even greater detail in Figure , and whereat it will be seen that, according to the invention, there is no sharp juncture between the power curve and the lenticular [as is the case with all of the prior art lenses] . Similarly as regards the blend, which may be sharp, medium or heavy. Moreover, the base curve need not be spherical, but will match the eyeball, whether spherical, aspheric, etc. The power curve may likewise be curve corrected to eliminate spherical aberration. Concentrics [for add , or otherwise] too are readily formed into the lens according to the invention with no discernible lines or junctures between zones. Thus, bifocal lenses, trifocals, omni-focals, aspheric lentic- ulars, aspheric lenticular running parallel to an aspheric base, all heretofore unknown to the art, are quite readily formed consistent with the invention. And so too a lens may be shaped having a changing rate of curve with a graduated power change in a transition zone between distance and add .The significance of the ability of the apparatus of the present invention to yield lenses of such compli¬ cated geometrical shapes, in a fundamentally simple and automated or semi-automated manner and yet with an exacting degree of reproducibility, is manifest when one considers the vagaries of eyeball geometries. Optimally, an eyeball • would be spherical for maximum optical resolution. However, it is found thatonly the central portion of the eyeball is even approximately spherical, while it tends to flatten as the radius from center increases. Thus, the eyeball is typically seen to be mathematically described by ellipitical, parabolic, and hyperbolic functions. Certain visual defects further compound these complicated geometries. For example, keratoconus-type defects results in an eyeball configuration exemplified as a cone, wherein the apex corresponds to the central corneal region. Currently, contact lenses have been found to be the only effective device for optical correction of this defect and, typically, the patient will be fitted with a series of lenses to promote, or indeed force, a more spherical shape for the eye. However, the ability to accurately and reproducibly form contact lenses for patients suffering kerataconus-type defects has been elusive, at best, and unsatisfactory as a general proposition. This is because each individual lens must first be roughly formed and then individually, hand polished to provide >;. a tolerable fit on the eyeball. In so fitting the lens, any conceivable reproducibility in the initial shaping is lost completely by the subsequent, trial-and-error polishing technique. This severe condition is completely eliminated by the computerized controlled system according 7 to the invention. Even considering a normal eyeball, the inability to precisely form the posterior surface of the lens by use of present machinery results in the need for the doctor fitting that lens to resort to additional lens polishing or modification to adequately fit the lens to the patient. Again, because of the ad hoc nature of this technique, any conceivable reproducibility is similarly lost. Therefore, should the patient lose or damage a lens, it becomes virtually impossible to match a replacement lens. The automated or semi-automated machine in accordance with the present invention eliminates all of the disadvantages inherent in the current trial-and-error methods employed. Any complex posterior lens geometry may be accurately and reproducibly generated to maximize not only wearer comfort, but insure stable and strictly repro- ducible correspondence with the eyeball surface. The. anterior surface may then be appropriately formed in order to effectively yield a spherical shape, at least in the optical zone, whereby optical resolution is similarly maximized. • - - ' The posterior surface A may be said to' be com¬ prised of a central base curve, r, , for contact with the corneal portion of the eyeball. Circu ferentially peripheral to the base curve is a secondary curve in order that the lens may, for example, transgress or vault the sensitive limbus and rest on the scleral region of the eyeball.The anterior surface B is likewise formed of a central , power curve having a radius r,, circumferentially bounded by a peripheral curve, x . . The lens terminates at an edge having a radius r_. designed to maximize wearer comfort.With particular reference to Figure 2, the process of the present invention comprises a series of interrelated, fully automated or semi-automated steps. A suitable hydrophilic polymeric material, preferably that described in United States Patent No. 3,721,657, is first polymerized under anhydrous conditions as illu¬ strated in the patent in the form of a cylindrical rod. Other suitable polymers include those disclosed in United States Patents No. 3,503,942, No. 3,532,679, No. 3,621,079, No. 3,639,524, No. 3,647,736, No. 3,700,761, No. 3,767,731, No. 3,792,028, No. 3,816,571, No. 3,926,892, No. 3,949,021, No. 3,966,847, No. 3,957,362, No. 3,957,740, No. 3,983,083, No. 3,699,089 and No. 3,965,063. The rod or bar is thence subjected to a centerless grinding or compomparable exacting machining operation under conditions of acceptable relative humidity, e.g., typically from 30--40%, to accurately render the circumferential surface circular to within, preferably, a diametral tolerance of about 0.0004 inches, preferably about 0.0001 inches. From the ground rod is then sectioned a lens blank or precursor 34. (For ease of description, the lens during its various stages of manu¬ facture will be identified with this numeral, 34). The sectioning of the lens precursor 34 may be made in any con- venient manner, desirably also under conditions of accept¬ able relative humidity, but most preferably, by an automati¬ cally fed precision lathe equipped with a standard parting tool which is itself machined or dressed to yield precise opposing faces of the lens precursor. The lens precursor or button thus defines a substantially cylindrical rod having opposing end faces and a circumferential face. The diameter of the button is reproducibly maintained within a tolerance of +0.001 inches, preferably of +_0.0002 inches, and most preferably of +0.0001 inches, while the longi- tudinal axis (thickness) also is reproducibly maintained within a tolerance of +0.015 inches, preferably of +0.010 inches, most preferably of +0.001 inches. Perpendicularity of both opposing faces relative to the outside diameter is-BU maintained within +0.0005 inches, preferably within +6.0004 inches, and most preferably within +0.0002 inches.The precision lens precursor 34 is then fed ' from, for example, a magazine load' to the air collet 24 of fluid-bearing spindle/motor 16, most preferably an air- bearing spindle such as those currently marketed by Westwind Air Bearings/Federal-Mogul. Once secured within the spindle, ■ the operator may then precisely align the cutting tool 22 with the exact center of the lens precursor 34, optionally with the aid of optional visual displays 32 and 33. To further assist the operator in so positioning the cutting tool, gradient markings may be provided on the screen of the visual display units, either by way of a transparent overlay or by actually generating an image on the cathode ray tube. Alternatively, the aforesaid precise alignment of the cutting tool with the exact center of the button 34 is accσmposihed, e.g., by physically measuring the tool position and comparing it to a precalibrated standard in the X, Y and Z axes.Once the operator has so defined the zero datum- point for the cutting- tool, the computer 12, having appropriately been programmed, will then accurately index the cutting tool 22 vis-a-vis the spindle/motor 16 by the control of conjoint movement of each of the fluid- bearing X-Y tables 14 and 14a, most preferably air-bearing tables such as those currently marketed by Pneumo Precision, Inc. Thus, in a first cutting operation, with both tables in simultaneous computer controlled movement at varying rates of speed, the outside diameter of the desired lens is cut into the lens precursor 34, as well as a portion of the edge radius. Subsequently, the secondary curve and the base curve of posterior surface A are formed as the tool 22 transgresses inwardly of the lens. Preferably t the posterior surface is cut or •formed in a series of passes incorporating both roughing and finishing cuts.Following the complete formation of posterior surface A, the machined optical surfaces may be polished, if needed. However, due to the enhanced accuracy and precision of the machining operation, an optical surface of from about .5 to about 4 micro- inches, is produced, thus rendering any subsequent polishing step optional.After the machining of the posterior surface A, the semi-finished lens is removed from the air collet 24 of spindle 16 by any suitable mechanical means. After appropriate quality control checks and inspections, the same is manually delivered to the lens blocking machine 100. The semi-finished lens is delivered to the upper spindle 126 of the machine 100 and is retained within air chuck 128. A preformed, preheated, precision lens block 114 having a machined surface 115 corresponding to the general average radius of curvature of posterior surface A is automatically loaded in rotatable spindle assembly 104 at. a first position corresponding to I of Figure 4. It is optimal that the positions of the semi-finished lens and the lens block be reversed. The table is then indexe '90° by an air switch to a position corresponding to II of Figure 4, whereat the lens block is registered adjacent dispensing apparatus 150. The arm 162 is actuated whereby the dispensing orifice 160 is disposed immediately adjacent the upper surface 115 of lens block 114 and a predetermined quantity of adhesive having the correct temperature and viscosity is deposited thereon. [In the., alternative reversed position embodiment, the adhesive, e.g., hot pitch, is directly applied to the semi-finished lens 34, which isthen rotated for even pitch distribution, . and thence the head of the lens block engaged therewith and fixedly adhered thereto.]The arm 162 is then retracted actuating a switch which causes the upper spindle assembly 126 to be displaced vertically downwardly, as described above, whereby the posterior surface A of semi-finished lens 34 is brought into intimate contact with the adhesively-coated lens block 114. Shaft 110 is then caused to rotate a predeter¬ mined number of revolutions, such as from about 5 to about-BUR 10, in order to .evenly distribute a coating on lens adhesive between the surface 114 and A of semi-finished lens 34. In this way, adhesive will adequately account for any negligible differences between the aspheric contour 5 of surface A of lens 34 and the surface 115 of lens block 114. Following this operation , spindle 126 is held in position. The spindle assembly 104_ is thence rotated to position III of Figure 4 to allow the adhesive to set or, if heated, to cool to a solidification temperature,10. followed by an indexing to position IV whereat the lens block-semi-finished lens assembly' is retrieved. Obviously, as the table is indexed through the positions I-IV other lens block assemblies may be fed thereto for affixing other semi-finished lenses as each position is freed upon com-15- pletion of a given step. Alternatively, all of the foregoing steps may be performed at but a single position.The lens block/semi-finished lens assembly is then, after appropriate quality controls, manually trans¬ ferred to air collet 24 of fluid-bearing spindle/motor 16,20 and the anterior surface B machined substantially as described above with respect to posterior surface A. That is, the fluid-bearing X-Y tables 14 and 14a are positioned by the operator to establish the appropriate reference point between tool 22 and the semi-finished lens25 34, followed by the machining of the remainder of the edge radius, the peripheral and/or lenticular curve and the power curve defining the anterior surface B in, preferably, - a series of passes incorporating both roughing and finishing cuts. Again, while the apparatus is capable of yielding30 a surface finish of from about .5 to about 4 microinches, the anterior surface may optionally be polished to improve the optical quality of the lens, should it be necessary or desirable for a given application. Following the formation of the lens, the lens block, finished lens assembly is35 automatically retrieved from air collet 24 and the lens demounted and subjected to typical quality control pro¬ cedures.When the lens to be produced is for a contact lens application, the optional polishing is neither required nor desired. The lens, as-machined, exhibits excellent optical surfaces for both compatability with the eyeball surface and optical resolution. As used in the specifica¬ tion and claims, the term as-machined connotes a lens which is removed directly from the forming or shaping apparatus and which is not subjected to a secondary or ancillary polishing operation. Such finished lenses produced according to the invention, whether as-machined or after having been subjected to any polishing operation, are readied for placement on the human cornea by hydrating the same to a soft, pliable state, of equilibrium with normal physiological saline solution. The hydrated lenses are also stored in normal saline solution. Obviously, since the contact lens buttons and the optical elements shaped therefrom consistent with the invention are comprised of synthetic hydrophilic polymers in their anhydrous or non-swollen state, it is desirable to avoid conditions of unacceptable relative humidity throughout each of the processing parameters in order to obviate premature, at least partial hydration.The computer controller 12 will control all of the automatic functions of not only the microinch surface generator 10, but will also, by insertion of basic prescrip¬ tion data, design total lens geometry, including all of the appropriate optical mathematical parameters necessary for generating the appropriate radii for forming the posterior and anterior surfaces of the lens. In addition, the computer will then compute the precise tool coordinates to achieve the predetermined continuous path for the lens geometry and sequence through the various steps necessary to yield the desired lens con¬ figuration. For example, the insertion of the kerato eter readings of a patient with keratocomus, plus the desired diameter of the lens, the computer will design an aspheric lens for an optimum fit upon that patient's eye. In the production of the anterior surface of such lens, by the insertion of the desired power and optical zone, the computer will establish the appropriate coordinates for-BU optimum vision correction in the optical zone and design an appropriate lenticular relative to the posterior side of the lens.In order to position the fluid-bearing X-Y •'. tables 14 and 14a, an analog to digital converter or interface may be interposed between the requisite 'drive means for the table and the computer output.Optionally, the apparatus according to the invention may be equipped with an X-Y plotter for the ' following purposes:[1] For the graphic illustration of the lens being generated by drawing a cross-sectional profile magnified 20 to 100 times to verify the accuracy of the computer input; [2] Conversely, utilizing the paragraph [1] illustration, by tracing a drawing magnified an exact _number of times the size of a desired lens, the computer will control the lens generator and generate a lens surface which is a duplication of the drawing; [3] By tracing a casting of the eye, or the eyeball .itself, the plotter will draw a profile of the cornea greatly magnified and feed the information into the computer for the production of a lens which will be the optimum fit on said cornea; [4] Trace from a photograph of the eye;[5] Trace from a template;[6] If the eye is topographically mapped, then the computerized plotter could draw a cross-section of the desired lens to fit this eye to all comfort degrees 0 and visual acuity, as well as produce all possible X-Y motions for the generation of the actual contact lens;[7] Also, if there are any generation errors in processing the lens, the deviations or errors could be entered into the computerized plotter and their actual 5 effects observed during manufacturing to illustrate over or under compensations. . Lastly, by utilizing the combination of the various elements according to the invention, the machining operation is conducted with a minimum of vibration, e.g., no greater than about 10 Hz, and an essentially vibration-free operation of no greater than about 2 to 4 Hz is not uncommon.While the invention has now been described in terms of certain preferred embodiments, the skilled artisan will appreciate that various changes, substitu¬ tions, modifications, and omissions may be made without departing from the spirit thereof. Thus, it will be appreciated that not only are soft contact lenses readily shaped according to the invention, but also the hard or typically PMMA lenses are likewise readily fabricated. And, indeed, the subject apparatus and computer controller therefor, are capable of designing virtually an infinite number of lens designs, for example, directly from the K readings of a keratometer. Accord¬ ingly, it 'is intended that the scope of the present invention be limited solely by that of the following claims. Bϋ | WHAT IS CLAIMED IS:1. In a machine for forming a plurality of optical surfaces on an optical lens precursor, to yield a lens adapted for proximate contact with an eyeball and defined by a posterior surface and an anterior surface, the improvement comprising:' ) rotatable spindle means including a lens precursor holder; b) base means for supporting and positioning a cutting tool; ' c) fluid motive means for fluidly supporting and positioning said base means in a plane; and d) automatic indexing means for: i) indexing a cutting tool to a face of a lens precursor while the same is rotating in said spindle means; and ii) imparting predetermined motion to said base means vis-a-vis said rotatable spindle means for shaping a surface on said lens precursor.2. The machine of Claim 1, further comprising a second base means for supporting and positioning said spindle means and second fluid motive means for fluidly supporting and positioning said second base means in a plane.3. The machine of Claim 2, said automatic indexing means further comprising means for imparting cooperating predetermined X and Y motion to said base and said second base means.4. The machine of Claim 1, wherein said lens precursor holder is an air collet.5. The machine of Claim 1, wherein said base means and said fluid motive means comprise an air-bearing table. 6. The machine of Claim 2, wherein said base means and said fluid motive means comprise an air-bearing table, and said second base means and said second fluid motive means comprise a second air-bearing table.7. The machine of Claim 5, wherein said air- bearing table is a Y-axis slide.8. The machine of Claim 6, wherein said air- bearing table is a Y-axis slide, and said second air- bearing table is an X-axis slide.9. The machine of Claim 2, further comprising means for Z-axis translation of the cutting tool.10. The machine of Claim 2, wherein the base means are adapted to fluidly support and position of plurality of cutting tools.11. The machine of Claim 10, further comprising means for Z-axis translation of each cutting tool.12. The machine of Claim 1, wherein said spindle is an air-bearing spindle.13. The machine of Claim 2, wherein said spindle is an air-bearing spindle.14. A machine for forming a plurality of optical surfaces on an optical lens precursor, to yield a lens adapted for proximate contact with an eyeball and defined by anterior and posterior surfaces, comprising a fluid-bearing microsurface generator for forming said surfaces. *. 15. The machine of Claim 14, wherein said microsurface generator comprises: a) an air-bearing spindle for holding and for imparting rotational movement to a lens precursor; b) an air-bearing Y-axis table for supporting and positioning a precision cutting tool proximate said precursor; and c) an air-bearing X-axis table supporting and positioning said air-bearing spindle.16. The machine of Claim 15, further comprising computation and control means for imparting coordinated predetermined X and Y motion to said air-bearing X-Y tables.17. The machine of Claim 1, said automatic indexing means comprising computer control.18. The machine of Claim 14, said microsurface generator adapted to operate at no greater than 10 Hz.19. The machine of Claim 14, said microsurface generator adapted to operate at no greater than 4 Hz.20. A precision lens button comprising a substantially cylindrical truncated rod of non-hydrated hydrophilic polymer defining opposed end faces and a circumferential face, the diameter of said rod having a tolerance of - 0.001 inches, the thickness of said rod being within a tolerance of - 0.015 inches, and the perpendicularity of both opposing faces relative to out¬ side diameter being within - 0.0005 inches.21. The precision lens button of Claim 20, the diameter of the rod having a tolerance of - 0.0002 inches, the thickness of - 0.010 inches, and the perpen- dicularity of +- 0.004 inches. 22. The precision lens button of Claim 20, the diameter of the rod having a tolerance of - 0.0001 inches, the thickness of - 0.001 inches, and the perpendicularity of - 0..0002 inches.23. An aspheric optical element of a non- hydrated hydrophilic polymer adapted for proximate contact with an eyeball, comprising an optical lens having pos¬ terior and anterior optical surfaces and a radiused edge, wherein at least said posterior surface is a composite of a plurality of optical surfaces each of which is defined by an individual posterior radius of curvature for correspondence with the changing rate of curvature of said eyeball, each of said individual posterior radii being accurate for said correspondence within a tolerance of 0.0004 inches.24. The optical element of Claim 23, said tolerance being of 0.0001 inches.25. The optical element of Claim 20, wherein said anterior surface is comprised of a composite of a plurality of optical surfaces each of which is defined by an individual anterior radius of curvature, and wherein each of said individual anterior radii being accurate for optical resolution within a tolerance of 0.0005 inches.26. The optical element of Claim 25, said tolerance being of Q.0001 inches.27. The optical element of Claim 23, hydrated to a soft, pliable state of equilibrium with normal physiological saline solution.•^ϋ 28. A method for forming a contact lens from a hard, anhydrous hydrophilic polymer lens button comprising the step of: a) inserting a truncated cylindrical hydrophilic polymer lens button in a rotatable fluid-bearing spindle; b) indexing a precision cutting tool borne upon a fluid-bearing microsurface generator support into proximate contact with said button; and, c) generating an optical surface on said lens button.29. The method of Claim 28, comprising generating an optical surface of no greater than 4 microinches.30. The method of Claim 29, wherein the fluid- bearing spindle is itself borne upon a fluid-bearing support.31. The method of Claim 30, wherein said optical surface is generated by computer controlled, conjoint indexing of the cutting tool vis-a-vis the lens button.32. The method of Claim 29, wherein said optical surface is generated at a vibration level of no greater than 10 Hz.33. The method of Claim 29, wherein said optical surface is generated at a vibration level of no greater than 4 Hz.34. The method of Claim 28, wherein said optical surface is generated along a predetermined path of infinite resolution. •*>- 35. A method for forming a contact lens from a hard, anhydrous polymer lens button, comprising generatin an optical surface on a first face of said button to a finish of no greater than 4 microinches, removing and blocking the semi-finished lens on a fixture therefor, generating another optical surface on the reverse face of said button, also to a finish of no greater than 4 microinches, and demounting a precision, optically microfinished lens from said fixture.36. The machine of Claims 1 or 2, said base means supporting a precision diamond-tipped cutting tool having a circular cutting surface within a tolerance of 0.005 inches truth of circular profile.37. The machine of Claims 1 or 2, said automati indexing being achieved by encoders with no greater than 0.5 micron resolution.38. The machine of Claims 1 or 2, further comprising means for controlling the radial and axial runout of the rotating spindle at no greater than 0.00001 inches T.I.R.39. The machine of Claims 1 or 2, further including video display means to permit viewing of an enlarged picture of the tool relative to the lens precursor.40. In combination, a semi-finished lens comprising a lens button of non-hydrated hydrophilic polymer having an optical surface of no greater than 4 microinch finish and a lens block having a surface of complementary geometric configuration -with respect to sai optical surface. 41. A lens block having an arcuate lens- supporting surface for receiving a semi-finished lens, and a back banking surface for locating said blocks in a collet means, the distance between said back banking surface and the apex of the radius of said arcuate surface being within a tolerance limit of - 0.001 inches.42. The lens block of Claim 41, said tolerance4- limit being of - 0.0005 inches.43. The lens block of Claim 41, said tolerance limit being of - 0.0001 inches.44. In a machine for forming a plurality of optical surfaces on an optical lens precursor, to yield a lens adapted for proximate contact with an eyeball and defined by a posterior surface and an anterior surface, the improvementcomprising: a) rotatable spindle means; b) base means for supporting and positioning a cutting tool; c) fluid motive means for fluidly supporting and positioning said base means in a plane; • d) lens block fixture means for receiving a semi¬ finished lens and adhering the same to a lens block; and e) automatic indexing means for: i) advancing said tool to a first face of said precursor- while the same is rotating in said spindle means; ii) imparting cooperating predetermined X and Y motion to said base means and said spindle for forming said posterior - surface to yield said semi-finished lens; iii) retrieving said semi-finished lens from said spindle means and delivering the same to said lens block fixture means; iv) retrieving a lens block/semi-finished lens assembly and delivering the same to said spindle means; and, v) imparting cooperating predetermined X and Y motion to said base means and said spindle for forming said anterior surface.5 45. The machine of Claim 44, further comprising automatic loading means for introducing said precursor within said spindle means.46. The machine of Claim 44, wherein said automatic loading means comprises a hopper feed loading10 member and wherein said spindle means includes collet means for receiving said precursor from said loading member.47. The machine of Claim 44, wherein said spindle is an air-bearing spindle.15 48. The machine of Claim 44, wherein said fluid motive means comprises an air-bearing Y-axis table.49. The machine of Claim 44, wherein said lens block fixture means comprises a plural stage, relatively indexable fixture table including: 20 a) at least one rotatable lens spindle means; b) means for depositing a predetermined quantity of adhesive on a lens block positioned within said lens block spindle means; c) translatable, semi-finished lens fixture25 means for securing said semi-finished lens and displacing the same to proximate contact with a lens block positioned within said lens block spindle means; and, d) means for rotating said lens block spindle means when said semi-finished lens and a lens block30. bearing said adhesive are in said proximate contact.-_J_ 50. The machine of Claim 49, wherein said translatable fixture means comprises: a) collet means for receiving and accurately positioning said semi-finished lens with said posterior surface oriented outwardly thereof; and, b) means for vertically translating said collet means for effecting said proximate contact.51. The machine of Claims 1 or 2, further including an X-Y plotter.52. A contact lens comprising a posterior surface including a base curve, an anterior surface including a power curve and a radiused edge, and wherein said posterior surface is aspheric.53. A contact lens comprising a posterior surface including a base curve, an anterior surface including a power curve and a lenticular and a radiused edge, there being no sharp juncture between said power curve and said lenticular.54. The contact lens of Claims 52 or 53, the same being comprised of hydrophilic polymer.55. The contact lens of Claim 54, the same being a bifocal lens.56. The contact lens of Claim 54, the same being a trifocal.57. The contact lens of Claim 54, the same being omni-focal.58. The contact lens of Claim 54, the same being an aspheric lenticular. 59. The contact lens of Claim 54, the same being an aspheric lenticular running parallel to an aspheric base.60. A polymeric contact lens comprised of5 machined anterior and posterior surfaces, said surfaces having a finish of no greater than 4 microinches in the as-machined state.61. A polymeric contact lens comprised of machined anterior and posterior surfaces, said surfaces10 having a finish of no greater than .5 microinches in the as-machined state.62. The contact lens of Claims 60 or 61, the polymer being a hydrophilic polymer.63. The method of Claim 28, wherein said 15 optical surface is generated via both roughing and precision finishing cuts. | AUTOMATED OPTICS; AUTOMATED OPTICS INC | SPRIGGS R |
WO-1979000084-A1 | 1,979,000,084 | WO | A1 | XX | 19,790,222 | 1,979 | 20,090,507 | new | E02B3 | null | E02B3 | E02B 3/04 | METHOD AND MEANS FOR BEACH RESTORATION | A method and means are provided for stopping erosion of beach areas and restoring the same by wave and wind activated formation of new dunes, by erecting on the beach area an elongate frame and screen structure (18) of lightweight materials and anchoring said structure to the ground. The frame members are arranged and interconnected to form a plurality of tetrahedral units (Fig. 3) which, in turn, are assembled so as to present to incoming waves a zigzag-shaped wall composed of screen sections (Fig. 2) inclined upwards and landwards, whereby to subject the structure to forces tending to press it down towards the ground and thus to retain it in position even before it is buried in accumulating sand masses. The invention includes special means (Figs. 4, 5, 6) for interconnecting the frame members and for anchoring the structure. | METHOD AND MEANS FOR BEACH RESTORATIONDESCRIPTION • ' Technical FieldThe invention relates to a method and means for pro- 5 ection and/or restoration of shores and beaches along oceans, lakes and rivers, where waves and floodings tend to cause erosion and in many cases danger and damage to the shore area itself and to installations on and adjacent •thereto, such as apartment buildings, summer homes, play- 10 grounds, parks, parking lots, streets and roads. Background ArtFor protection of such shore areas it has been common practice to build breakwaters, usually of concrete or rock ridges, to prevent erosion of the areas located landwards 15 thereof. Such breakwaters are expensive to erect and in many cases undesirable for various practical and esthetic reasons. For similar or related purposes various other means have been employed. Thus, for example, according to U.S. patent 2835112 apertured elements made of reinforced 20 concrete or shaped steel are employed to stabilize earths or materials in movement in connection with defense dams on a sea front, such elements being held together and suitably anchored by means of cables.Other means for controlling erosion conditions, partic- 25 ularly by fast-flowing river waters, are described in U.S. patent 3386250 and consist of apertured concrete blocks firmly anchored in the river bed in various configurations. Other constructions for similar purposes are known from U.S. patents I389513, 1716509. 20973^2 and 2803113. 30 Disclosure of InventionThe means according to the invention comprises an elon¬ gate truss of lightweight tubings extending substantially along the shoreline and resting on the ground, with anchor- * ing means of similar lightweight construction projecting 35 downwardly into the ground to prevent overturning or dis¬ placement of the truss due to wind and wave activitities,OMPI before it has been covered with gradually accumulating sand. The truss and the anchoring means are preferably in the form of a framework composed of a plurality of aluminum or- aluminum alloy tubings of substantially equal length and diameter which are assembled according to a distinct and universal pattern to be described below. A number of rela¬ tively fine- mesh screens are mounted in certain positions within the truss for a purpose which will become evident, as the description proceeds. -Brief Description of DrawingsIn the accompanying drawings a preferred embodiment of the invention is shown, and in said drawings -Fig. 1 is a cross-sectional view, generally perpendic-- ular to the shoreline, of a building separated from said shoreline by a beach area with a device according to the invention thereon,Fig. 2 is an enlarged view of the truss from above, with the location of the screens indicated by cross-hatch¬ ing, Fig. 3 is a perspective view of a tetrahedral assembly of six struts forming one unit of many, of which the truss and anchoring, means may be considered to be composed,.Fig. is a top (or bottom) view of generally spheri¬ cal elements used for joining the struts, Fig. 5 is a side view of an alternative joint between the struts,Fig. 6 is a perspective view of one of the anchoring means, shown in position to be lowered into the hole in the ground where it is to be located, and Fig. '7 shows diagrammatically the anchoring means as¬ sembled with the truss and in position in the hole in the ground, before said hole has been filled with sand. Best Mode For Carrying Out The InventionFig. 1 illustrates diagrammatically the typical condi- tions at a lakefront summer home, where at the time• the•.building 10 was -erected a beach area 12 separated the build¬ ing 10 from the normal waterline Ik . Through storms and ac¬ companying wave action the beach surface has gradually been - 3 - eroded, until it has assumed a profile approximately as in¬ dicated by line 16. On a portion of this beach area 16, which is, or is made, reasonably level, the breakwater structure 18 according to the invention is then erected:5 with the truss 20 extending generally parallel with the waterline 14 and with the anchoring means 22 buried in the ground at .intervals along the truss 20, which may consist of a single layer of tetrahedral frame units, as indicated in full lines, or have• additional such layers added there- 0 to, as indicated in dotted lines,'depending upon the actual shape of the eroded beach surface and the shape desired to be achieved.The truss 20, a section of which is shown on a larger scale in Fig. 2, comprises a base network of struts of equal15 length joined at the ends to form a pattern of triangular bases arranged side by side. Thus, for example, starting from the waterfront side of the truss, the struts 2 , 26, 28 form a first triangular base, struts 30, 32, 34 form a sec¬ ond triangular base, in which strut 30 is aligned with strut20 24, and struts 36, 38, 40 form a third triangular base hav¬ ing strut 36 aligned with struts 2 and 30. Aligned struts 2, 44 interconnect the tops 46, 48, 50 of said three tri¬ angular bases. From the three corners 46, 52, 54 of the first triangular base three struts 56 , 5& > 60 extend upward-25 ly to form together with struts 24, 26, 28 a pyramid, or a tetrahedral figure, having its vertex at 62 (compare Fig.3) . Similar conditions prevail in respect of the second and third triangular bases with vertexes at 64 and 66 , respec¬ tively. Vertexes 62, 64, 66 axe interconnected by inter-30 aligned struts 68, 70 which accordingly are parallel with base frame struts 42 and 44, respectively, and located at a level above that of said first, second and third triangular bases. On said higher level, struts 72, 74 extend from ver¬ texes 62 and 64, respectively, to a junction point 76 which35 constitutes the vertex of a pyramid, or tetrahedral figure, having for its base the triangular base formed by struts 78, 80, 82 and connected with the corners 54, 84, 86 of said triangular base by inclined struts 88, 90, 92. Sincp vertex 76 is connected by interaligned struts 94, 96 to ver¬ texes 98, 100, etc., of other triangular bases and on the same higher level, it is obvious that a second row of iden¬ tical pyramids, or tetrahedral figures, is formed alongside the row of pyramids formed on the aforementioned first, sec¬ ond and third triangular bases, the pyramids of said second row being.of set by half a strut length along the truss in relation to the pyramids of the first row.Obviously, in the- embodiment shown, a third row of identical pyramids having their respective vertexes 102, 104, etc., extends along the truss in identical arrangement and connection with the second row, and in the embodiment comprising three adjacent rows of such pyramids the aligned base struts 106, 108, etc., constitute the back edge of the truss, as seen from the waterfront. It is obvious also, that the vertexes, such as 62, 76 , 98, on the second level of the truss may serve as base supports for a'row of iden¬ tical pyramids (not shown) having their vertexes on a third level above the ground. Incidentally, tetrahedrons such as 68, 72, 74, 60, 90, 110 which alternate with the previously described pyramids in each row, may be described as invert¬ ed pyramids , since they have their triangular bases on the level next above the level, where their vertexes are disposed. The means for joining the struts together may all be identical, and an example thereof is shown in Fig. 4 which represents junction 7 in Fig. 2. It consists of a light¬ weight spherical ball provided with six holes 130 having their central axes in a common plane which in the case of junction 76 is horizontal. The holes 130 are evenly distrib¬ uted around the circumference of the ball 76 and each re¬ ceives the end portion of a lightweight strut which is weld¬ ed or brazed in place. In the case of ball 76 said six horizontal struts are 72, 74, 94, 96, 132 and 134 and in ad- dition ball 76 is provided on its bottom side with three holes (not shown) adapted to receive the upper end portions of the inclined struts 88, 90, 92, while on its top side it has the three holes 136 which in Fig. 2 are unoccupied but in position to receive the lower end portions of inclined struts (not shown) for support of a third layer of struts on the second level above the ground. Accordingly, all the balls are identical and each provided with holes arranged;5.and adapted to receive a maximum of twelve struts.An alternative construction of a joint, such as at 76 , between nine, struts is shown diagrammatically in Fig. 5' As indicated, the end portions of the struts have been flat¬ tened out and, in the case of the inclined struts 88, 90,10 92, bent, whereupon the flattened portions are placed on top of each other (in Fig. 5 shown separated from each other for clarity of illustration) and clamped together by means of a bolt 140 inserted through previously drilled holes in the flattened strut portions and retained by a nut15 142 on its projecting end.In the truss 20, as described above and shown in de¬ tail in Fig. 2, a plurality of relatively fine mesh screens are secured to certain of the struts to cover selected areas enclosed by said struts. Some of said screen-covered areas20 have been indicated by cross-hatching in the righthand por¬ tion of Fig. 2 only, in order to avoid a cluttered appear¬ ance of said Fig. 2 due to the numerous reference letters.in the lefthand portion thereof. It- is noted that in all said selected areas, as e.g. the area 50, 66 , 112, 114, the25 screens extend from aligned struts 38, 116, 118 on the ground level to aligned struts 120, 122 on the second level, . which means that all the screens covering such selected areas are inclined upwardly and rearwardly, as viewed from the waterfront side. Accordingly, waves impinging upon the30 screens tend to force the screens, and thereby the entire truss 20, rearwardly and downwardly toward the ground, thus - together with the anchoring means 22 - counteracting wave and wind forces tending to lift the front edge portion of the lightweight truss up from the ground and dislocating it35 from its designated location. It is obvious that corres¬ pondingly located screens (not shown) between the second• level of the truss and a third level thereof form aligned extensions upwardly and rearwardly of the screens des-IJTTREAITO PI' y cribed above.Since the screens shown in Fig. 2 cross each other at various places, such as along the inclined strut 144, it is necessary to cut them in sections, before they are mounted 5 in the truss. Said sections are then attached to appropri¬ ately located struts by welding or brazing. For example, one screen- section in the form of a equilateral rhombus may cover the area enclosed by the struts 144, 38, 146 and 120 and have its edges secured to said four struts and, if foun 0 desirable, it may also be secured- to strut 148 which is lo-' cated in the same plane. An identical screen section may b secured to struts 144, 122, 148 and 116, and so forth. In fact, in the embodiment of Fig. 2 all the screen sections are identical except those in the third (landward) row of 5 the truss, where each screen section, such as the one en¬ closed by struts 118, 148 and 150, is in the form of half a equilateral rhombus. It may be remarked, that in some in¬ stallations it has been found that a satisfactory effect of the breakwater is achieved with considerably less total 0 screen area. In such cases all the screen sections may be of this lastmentioned form and all the top sections, such as the one bordered by struts 120, 144, 148, omitted.The anchoring means 22 (Figs. 1, 6 and 7) are prefer¬ ably structures of basically the same kind as the truss 20 5 and attached thereto at intervals of approximately 4 - 6 meters. For example, a truss (Figs. 1 and 2) may be placed upside down on the beach, so that it rests on the struts which in Fig. 2 form the aforementioned second level of the truss, such as struts 68, 72, 74, 94, 96, 132, 13^> 160, 0 etc. On the ground level frame structure then facing up¬ wardly a pyramid comprising an assembly of tetrahedral unit of the kind described is then erected having for its base, e.g., the triangular frame 50, 162, 114 (Fig. 2). Obvious¬ ly, the next higher layer of identical tetrahedrons (right- 5 side up and inverted) would have for its base the struts' 164, 170, 166, 122, 168 and 120 which together form the tri angular frame 66, 104, 112.These inclined struts (not shown in Fig. 2) extend upwardly from the junctions 66 , 100, 172 to form a vertex' (not shown) on the next higher level, and the same is true with regard to the other two triangles 104, 174, 100 and 174, 112, 172 on this second level. Said three vertexes on_ 5 the third level are interconnected by struts (not shown in Fig. 2) which together form the base of a pyramid having its vertex on a'fourth level, said last-mentioned vertex 176 (Figs. 6 and 7) forming the top point of the pyramid assem¬ bly having the triangle 50, 162, 114 for its base. 0 An anchoring means 22 of this kind is shown diagram¬ matically on a smaller scale in Fig. 6 in a position ready to be lowered into its hole 180 in the beach ground. The anchor may be secured to the truss as described above at - this time, although said truss is omitted from Fig. 6. The15 arrow 182 corresponds to arrows 182 in Fig. 2, and it is ob¬ vious, therefore, that the landwards side of the anchor is at 184 and is covered by a thin solid sheet of lightweight metal which is secured (by welding or brazing) to the struts enclosing the triangle 114, 162, 17 and, optionally, to 0 other struts in the same plane. The main function of the sheet 184 is to counteract any tendency of the truss to be displaced in a landwards direction under the influence of wind and/or impinging waves.Fig. 7» showing a diagrammatic side view of the anchor25 22 and the attached truss 20 in position on the beach, is selfexplanatory. It should be noted, that although the an¬ choring means 22 has been described above as attached to the underside of the truss 20 in such a position that the tri¬ angular area 50, 114, 162 coincides with the similarly,30 marked area of the truss, i.e. with the portion of the an¬ chor rearwardly of said area projecting rearwardly beyond the landwards side of the truss, it has frequently been found advantageous to secure the anchor 22 to the truss in a position, where a still larger portion of the anchor pro-35 jects beyond the truss, i.e. the seawardly facing junction 50 of the anchor may be secured, for example, to junction 190 of the truss, or even to junction 142 thereof, thus placing the major portion of the anchor landwardly of theIJTJREA TOMPI _ truss. The beneficial effect of such an arrangement is to- increasingly counteract any tendency of wind and wave forces acting on the lightweight truss from the waterfront side to- lift the truss and tilt it over, before the truss has been 5 buried in sand.In operation, the truss functions sLmilarily to an or¬ dinary solid breakwater or seawall, e.g. of concrete, but with the difference that the screens absorb the energy of • the waves less abruptly and allow a considerable portion of 0-the wave water to continue through-, over and beyond the truss. However, a portion of the sand carried by the waves is stopped by the screens and deposited within the area of the truss, and the force of the waves is diminished to a- certain extent, until it gradually is spent completely in 5 the area within and/or beyond the truss, causing another portion of the wave-carried sand to settle down. The more slowly receding water passes through the screens from be¬ hind, and any sand still carried thereby that not passes through the screens, is deposited behind the same. Repeated 0 wave action of this kind gradually causes the formation of a new dune, which eventually completely buries the truss. The process may take months or merely a few weeks depending upon the frequency and violence of the wave action. Wind- borne sand is, of course, also partially stopped and deposi- 5 ted by the screens, and when the new dune has been building up to the top level of the truss , wind and wave borne sand continues to be deposited and retained landwards of the dune, until the original beach level 12 (Fig. 1) is again approximately restored. As the new formation settles, veg- 0 etation may begin to cover at least parts thereof, and it has been noted that as this development progresses, such vegetation is often greatly stabilized'by roots clinging to and winding around the buried screens and struts of the truss. In any case, erosion of the restored beach is per- 5 manently stopped and danger to shore installations due to 'erosion is eliminated. Industrial ApplicabilityThe preferred construction of the strut and screen assembly described above and shown in the drawings may, of course, be modified to some extent without departing from the scope of the attached claims, as long as the breakwater and dune-forming characteristics thereof are retained. It is noted also, that, if found desirable, the original truss 20 may be enlarged before or after* installation as mentioned above and indicated by dotted lines in Fig; 1.Each truss may be assembled entirely on the site where it is to be located, or sections thereof may be assembled in a manufacturing plant at some other location and trans¬ ported by truck, train or the like to the site, where the sections are joined together. In either case, the process is very simple and inexpensive. 'Depending upon the width of the beach area, it may also be desirable to erect two or more trusses at different distances from the water front or even, in some cases, at least partly within the water.IJUREATΓOMPI | CLAIMS 1. A method of stopping erosion of beach areas and re¬ storing them by wave and wind activated formation of new dunes, comprising the steps of erecting on said beach area substantially along the waterfront an elongate frame and screen structure of lightweight materials, and anchoring said structure to the ground, thereby forcing wave and wind- borne sand to accumulate within and around said structure to form a new dune. 2. The method according to 'claim 1, in which said 'frame and screen structure is arranged to present to incom¬ ing waves a continuous zigzag-shaped screen wall by attach¬ ing a plurality of flat screen sections to members of the frame structure in such a way as to make each screen see- tion extend upwardly and landwardly, whereby incoming waves - will exert upon said screen sections a force tending to press the structure downwardly against the beach ground and thus to retain it in position in counteraction to wind and wave orces tending to move or tilt the structure. 3- A device for stopping erosion of beach areas and re storing the same by wave and wind activated formation of new dunes, characterized by an elongate frame and screen struc- ture of lightweight materials forming an elongate truss (20) and means (22) for anchoring said truss on the beach ground in a position substantially parallel with the waterfront and at an angle to incoming waves.4. The elongate truss according to claim 3 , charac¬ terized by - a) at least two parallel and laterally connected rows of interconnected frame units, each consisting of six light¬ weight tubular struts (24, 26, 28, 56 , 58, 60) of substanti- ally equal lengths which are joined together three and three at their ends to form an open-sided tetrahedron with a sub¬ stantially horizontal triangular base (24, 26, 28) and a ver tex (62) thereabove; b) means (54) connecting a base strut (24) in one of said tetrahedrons of each row with a substantially aligned base strut (30) in a neighboring tetrahedron of the same row, so as to place the top joint (46) of each triangular base in said row forwardly of its base strut; c) means connecting each of said top joints (54) in the . rearwardly row of tetrahedrons with one of the joints be- -tween said aligned base struts (24, 30) of the front row of tetrahedrons to thus offset the rearwardly row of tetrahe¬ drons longitudinally by substantially one half strut length in relation to the front row of tetrahedrons; - d) lightweight tubular struts (72, 74) interconnecting the '.vertexes (62, 76) of said tetrahedrons in the front and rearwardly rows separately; and e) screens attached to said struts and at least partly cov¬ ering the inclined sides of the tetrahedrons extending rear-- wardly from said top joints (46, 48, 5°) of the triangular 5 bases.5. The elongate truss structure according to claim 4, including lightweight tubular struts (42, 44) interconnect¬ ing said top joints (46, 48, 50) of the triangular bases in said front row of tetrahedrons. 0 6. The elongate truss structure according to claim 4, in which the struts connecting the vertex (62) of a tetrahe¬ dron in said front row with the vertexes (98, 76). of two tetrahedrons in said rearwardly row, together with the strut (94) interconnecting said two rearwardly vertexes, serve as 5 the triangular base for a tetrahedron in a higher level row of tetrahedrons arranged and connected similarly to the tet-- rahedrons on the lower level, whereby the rearwardly in¬ clined front vertex struts (not shown) of the higher level row of tetrahedrons form direct continuations of the corres- 0 ponding vertex struts ( 5^>) of the lower level tetrahedrons. 7. The elongate truss structure according to claim 4, in which the strut connecting means (Fig. 4) comprises a sub¬ stantially ball-shaped member (76) provided with twelve sur¬ face openings (130, 136) , the central axes of which intersect 5 each other at the center of the ball-shaped member, each of •said openings being of a size and shape corresponding to the cross-section of one of said struts, six of said openings (130) being equally spaced in a central horizontal zone-BURE EΓO PI _ around the ballshaped member, while three openings (136) are equally spaced in each of an upper and a lower parallel zone and have their central axes inclined outwardly by 6θ° to the- horizontal plane, each of the openings in said upper zone5 -being circumferentially offset by 30° from the closest open¬ ings in the central zone, and each of the openings in said' lower zone -being circumferentially offset by 60 in relation to the openings in the upper zone.8. The elongate truss structure according to claim 4, 10. in which the strut connecting means (l4θ, 142), at each j.oint comprises a bolt and nut assembly clamping together end portions of the struts, which are flattened and properly bent to be placed in parallel on top of each other and pro-- vided with aligned holes for the bolt.15 9- The elongate truss structure according to claim 4, including a plurality of anchoring means (22) secured to said truss (20) at intervals along its length and each com¬ posed of tetrahedral units as described, assembled in an up¬ side down position to form an inverted pyramid for burying20 in the ground, the landward side of said inverted pyramid being covered with a metal sheet (184) attached thereto. BUREA OMPΓ . k. WIPO | MANSEN D | MANSEN D |
WO-1979000086-A1 | 1,979,000,086 | WO | A1 | XX | 19,790,222 | 1,979 | 20,090,507 | new | B01D37 | B01D41 | B01D29, B01D37 | B01D 29/00A10R, B01D 29/00A38, B01D 29/32+/38, B01D 37/02 | METHOD AND APPARATUS FOR REGENERATING FILTERS | In the field of pressure filter systems, a method and apparatus for re- generating a diatomaceous earth filter cake of a pressurized liquid filter system in order to solve the problem of down time and one-time only use of the filter material concomitant with prior backflushing methods by liquidizing the diatomaceous earth filter cake formed on filter elements (26) in the filter chamber (18) of the system; by uniformy mixing with the liquidized diatomaceous earth the insoluble particles, or unpurities, removed by the filter cake from liquid that has passed through the cake; and by reforming the fluid cake with the impurities uniformly distributed throughout the filter cake. The liquidizing of the filter cake and impurities and mixing of the diatomaceous earth and impurities result from oscillations induced in the liquid in the filter chamber by several cycles of rapid reversal of the flow of liquid through the filter chamber. | METHOD AND APPARATUS FOR REGENERATING FILTERSDESCRIPTIONField of the InventionThis invention is in the field of pressure filter sys- *terns in which a pressure differential in the liquid being filtered is maintained across a filter element and particu¬ larly to such systems in which the filter elements are hol¬ low porous wall filter tubes whose filtering capability are significantly enhanced by forming on the surface of the por¬ ous walls of the filter tubes filter cake from finely divid¬ ed filter material by causing the liquid portion of a slurry of the filter material and liquid to flow through the filter tubes. More particularly this invention is in the field of methods and apparatus for regenerating the filter cake of such filter systems so that the useful life of the filter material forming the filter cake is significantly extended.Description of the Prior ArtPressure filter systems for removing undesirable insol¬ uble solids from a liquid such as water are well known in the art. Typically these systems have a pressure vessel whose interior is divided into a filter chamber into which the liquid to. be filtered is introduced and a filtrate cham¬ ber into which the filtered liquid flows. The filtering elements are hollow filter tubes having porous walls which are mounted in the filter chamber with the interior of the filter tubes in communication with the filtrate chamber. The mounting means for the filter tubes divides or isolates the two chambers so that liquid can flow from the filter chamber to the filtrate chamber only after passing through a filter tube. The surfaces of the filter tubes have built up on them a layer of filter material, diatomaceous earth, to form a filter cake. The filter cake is produced by form¬ ing a slurry of diatomaceous earth with the liquid to be filtered, water for example, in a precoat tank and the slur¬ ry is then pumped into the filter chamber. As the liquid portion of the slurry flows through the porous walls of the filter tubes, the diatomaceous earth builds, or forms, the filter cake on the exterior cylindrical surfaces of the porous walls of the filter tubes. After the filter cake is formed the liquid to be filtered is pumped into the filter chamber and flows through the filter cake into the hollow portion of the filter tubes and through the tubes to the filtrate chamber. The filtrate then flows through an out¬ let pipe to where it is to be used or stored.Undesirable elements in the fluid being filtered, im¬ purities are trapped or retained on the outer surfaces of the filter cake. As filtration continues the solids retain on the surface of the filter cake create a substantially impermeable crust. The flow rate of the liquid through the filter system is reduced and the pressure in the filter chamber increases. When the efficiency of the filter sys- tem decreases due to the resistance of the filter cake to the flow of fluid through it because of the impurities on the surface, the prior art teaches regenerating the filter cake by backflushing the filter system. In a backflushing operation, the liquid in the filter system is forced to flo in the opposite direction from normal through the porous walls of the filter tubes to remove the filter cake and re¬ move the trapped impurities from the tubes which then flow through a sludge opening in the bottom of the filter cham¬ ber to. a sludge receiver. Backflushing or backwashing can be accomplished by introducing compressed air into the fil¬ trate chamber of the system. The filter tubes are then re- coated with fresh clean diatomaceous earth to reform the filter cake prior to resuming normal operation of the filte system. The problem with the prior art's manner of regeneratin the filter cake once it has been clogged with solids remove from the filtrate is that it uses the filter powder or ma¬ terial only once. Further, the cleaning of the filter sys¬ tem and precoating of the filter tubes requires time during which the filter system is out of operation or production and thus reduces the overall capacity of the filter system. There have been attempts in the past to reuse and regenerate the filter cake without dumping the filter media each time. These procedures, up until now, have proven to be only partially successful and produce additional problems not encountered before. When the pressure drop across the filter tubes increases to a point that indicates that the surface of the filter cake is substantially clogged with contaminants or sludge, a vibrator or hammering device has been applied to the tube support sheet in an effort to dis¬ lodge and break up the filter cake from the tubes. Theore- tically, the filter cake is to be placed back into solution in the liquid, but the hammering only partially breaks the cake loose from the tubes and what cake is removed usually remains in relatively large chunks preventing an even re¬ generation of the cake on the tubes. In addition, another problem occurs in that the mechanical forces on the tube sheet and vessel can cause leakage around the tube flanges or even in the vessel flanges. An externally leaking filter is naturally undesirable. An internally leaking filter is intolerable in that the contaminants pass through to the outlet defeating the purpose of usefulness of the filter.Summary of the InventionThe present invention provides a method and apparatus for hydraulically regenerating the filter cake formed by depositing filter particles from a slurry of such particles o a porous filter surface on a filter element in the filter chamber of a liquid filter system. This is accomplished by causing the liquid in the pressure vessel of the system to oscillate through several cycles by rapidly reversing the direction of flow of the fluid in the filter chamber. The hydraulic oscillations of the liquid liquidize, or put into suspension, the filter material of the cake and the solid material removed from the filtrate and thoroughly mix them. The mormal or forward direction of flow of liquid through the filter chamber is then resumed to reform on the porous filter surface a new filter cake which has distributed through it the solid material removed from the filtrate'BUREAUOMPI . >- W1P0 ,Λ during the prior operation of the filter system.To produce rapid oscillations of the liquid to regene¬ rate the filter cake the filter system is provided addi- • tional'ly with a surge pipe through which liquid within the filter chamber can flow into the precoat tank of the system A surge valve controls such flow, or permits such flow, onl during a regeneration cycle of the filter system.It is therefore an object of this invention to provide a method and apparatus to regenerate in the filter chamber the filter cake of a liquid filter system.It is another object of this invention to provide a method and apparatus to permit the repetitive use of the same filter material in a pressurized liquid filter system. It is still another object of this invention to regene rate the filter material of a liquid filter system which makes it possible to use the same filter material for many cycles of operation and thus produces a significant savings in materials and labor necessary to filter a given amount of liquid under comparable conditions. This significantly increases the efficiency or productive capacity of the fil¬ ter system because the period of time the filter system is being serviced is significantly reduced.Brief Description of the DrawingsOther objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and mod¬ ifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:FIGURE 1 is a side elevation of a filter system embody¬ ing the invention;FIGURE 2 is an enlarged fragmentary sectional view taken on the plane of line 2-2 of Figure 1; FIGURE 3 is a schematic block diagram of a filter sys¬ tem embodying the invention; FIGURE 4 is a fragmentary perspective view partially broken away to show details of a filter tube;FIGURE 5 is a schematic view illustrating the flow of liquid through a filter tube when the normal direction of flow is reversed;FIGURE 6 is a schematic view illustrating the formation of a filter cake; and FIGURE 7 is an enlarged fragmentary sectional view taken on the plane of line 7-7 of Figure 4.Description of the Preferred EmbodimentsIn Figure 1, pressurized liquid filter system 10 has a pressurized filter vessel or housing 12 which has a pressure dome 14 bolted to it. As is best illustrated in Figure 2, the interior of housing 12 and pressure dome 14 are divided by filter tube support disc or sheet 16 into a filter chamber 18 and a filtrate chamber 20. The interior of the low tapered portion of vessel 12 forms a sludge chamber 22*.A plurality of filter tube receiving openings 24 are formed in support sheet 16 through each of which is placed a filter tube 26. Each filter tube 26 has a cylindrical collar 28 which has a flange 29, preferably formed integral¬ ly with collar 28 as is best illustrated in Figure 2. Filter tubes 26 are held in place by filter tube retainer disc 30 which is bolted to support disc 16 by a plurality of nuts and bolts with the flanges 29 of each of the tubes 26 positioned between support disc 16 and retainer disc 30. An O ring 32 is placed between each of the flanges 29 and the support disc 16 to prevent liquid in filter chamber 18 from flowing into filtrate chamber 20 except as a result of flowing through a filter tube 26.Each filter tube 26, as is best illustrated in Figure 4, is hollow and has a metal helical spring 34 which is fixedly secured to collar 28 by welding, for example. A standard stainless steel screen mesh 36 is wrapped around the outer surfaces of coil spring 34 and is spot welded to it. The helical spring's chief function is to position BU EAU OMPI ,- WIPO screen 36 and to prevent its collapse due to the pressure a- cross it as liquid flows through it. The lower portion of each filter tube 26 is closed off by a cap 38 which is fixed ly secured to spring 34 and screen 36 to prevent liquid from flowing directly into the interior of tube 26 without flowin through screen 36. Conventional centrifugal pump 40 has its intake port 41 connected to a source of liquid to be filtered such as the contents of inlet tank 42 or to the liquid in precoat tank 4 through conventional pipes or fluid conductors as determined by the state or condition of valve 46. Valve 46 when it is i its first state or condition connects intake port 41 of pump 40 to inlet tank 42. When valve 46 is in its second state o condition it connects intake port 41 of pump 40 to precoat tank 44.Fluid from output port 47 of pump 40 can flow into filter chamber 18 through conventional piping depending upon the state or condition of valve 48. When valve 48 is in its first state, fluid from pump 40 flows into filter chamber 18 through filter inlet pipe 49. When valve 48 is in its second state, liquid from pump 40 is directed to valve 50. Valve 50 when in its second state, and if valve 48 is in its second state, causes the output from pump 40 to flow into the fil¬ trate chamber 20 through filtrate pipe 51. Valve 50 when in its first state or condition permits fil¬ trate to flow from filtrate chamber 20 to valve 52. Valve 52 when in its first state causes filtrate to discharge into filtrate tank 54. When valve 52 is in its second state, fil¬ trate will be discharged into precoat tank 44. Liquid can al so flow from the filter chamber 18 into precoat tank 44 through surge pipe 56 when surge valve 58 is in its second stage. When surge valve 58 is in its first condition, or stage, surge line 56 is closed or blocked, and no liquid can flow from filter chamber 18 into precoat tank 44. Filtrate pipe 51 is provided with a sight glass 60 and a blow down shut off valve 62. A conventional pressure gauge 6 is mounted on dome 14 and a pressure safety valve 66 is also mounted on dome 14. To backwash filter system 10, compressed air can be applied to filtrate chamber 20 through compressed air line 68 which is provided with a valve 70 to turn on or off compressed air from a conven¬ tional source which is not illustrated. Sludge line 72 runs from the bottom of sludge chamber 22 to a conventional sludge receiver which is not illustrated. Line 72 is provided with a sludge valve 74 which when closed prevents any fluid from flowing through line 72 and when it is open permits sludge, impurities and filter materials, as well as liquid in filter chamber 18 and filtrate chamber 20 to be forced out of the system. The fluid conductor from inlet tank 42 'to valve 46, in a preferred embodiment, is provided with a conventional check valve 76, and filter inlet pipe 49 is also provided with a check valve 78. The conductor from pump 40 to valve 48 is provided with a conventional pressure control valve 80 in a preferred embodiment.Inlet, or inlet tank 42, is kept filled with the liquid to be filtered which liquid flows into tank 42 through pipe or liquid conductor 82. The source of the fluid to be fil- tered can be, for water, such natural sources as wells, lakes, reservoirs, or rivers; or the source could be the effluent from various industrial processes, swimming pools and the like. Filter systems of the type disclosed can also be used to filter fluids other than water such as dry clean- ing fluids and the like.The first step in putting filtering system 10 into op¬ eration is to fill the system with the liquid to be filtered. This is accomplished by setting valve 46 to its first state, which connects inlet port 41 of pump 40 with liquid in the inlet tank 42. Valve 48 is set to its first state which directs fluid from pump 40 into filter chamber 18. Surge valve 58 is put in its first state so that liquid from with¬ in filter chamber 18 cannot flow through surge line 56 to precoat tank 44. Valve 50 is put in its first state and valve 52 is placed in its second state so that when filtrate chamber 20 is filled with liquid, the liquid can flow into precoat chamber 44 which in a preferred embodiment is open at the top. Pump 40 is started and run until precoat tank 44 is substantially full of liquid at which time pump 40 is -stopped.The next step is to precoat the filter tubes with an appropriate filter material, or to form the filter cake on the exterior surfaces of the filter tubes 26. In a prefer¬ red embodiment, the filter material, or powder, is diatom¬ aceous earth, or diatomite. Valve 46 is positioned to its second state in which pump 40 pumps water from precoat tank 44 rather than from inlet tank 42. The states of the re¬ maining valves of the system are the same as for filling th system and thus are unchanged. Pump 40 is started and the proper amount of filter material is poured into precoat tan 44 necessary to form a coating, or cake, on the mesh or screen 36 of each filter tube 26. The thickness of the cak in a preferred embodiment is substantially one-eighth of an inch. After all the filter material is poured into precoat tank 44, and the amount is a function of the area of the filter tubes, the pump 40 is kept running until the liquid flowing past the sight glass 60 is clear, which indicates that the filter cake 82 has been formed on the filter tubes 26.To go on stream or to start a production run, it is only necessary to reposition valve 46 to its first state so that pump 40 draws liquid from inlet tank 42 and valve 52 to its first state which causes filtrate from filtrate chamber 20 to flow into filtrate tank 54. . Filtrate in tank 54 is removed through outlet pipe 84. Part of the filtrate can be mixed or added to the liquid in inlet tank 42 to improve the degree of filtration, if desired, by permitting some of the filtrate to flow into tank 42 as is illustrated in Figure 3.During the production cycle liquid to be filtered flows through the filter cake 82 as is illustrated in Figure 7, which is built up on the upstream side of mesh 36 from the individual diatoms in the slurry, pumped through the system during the precoating cycle. As liquid to be filtered flows through filter cake 82, the solid particles suspended in the liquid are removed or retained on the outer surfaces of cake -82. As the production cycle continues, or filtration con¬ tinues, the solids retained on the surface of filter cake 82 create a substantially impermeable crust or layer. This causes the resistance of the filter cake to the flow of fluid through it to increase, reducing the flow and increas¬ ing the pressure of the liquid in filter chamber 18. When the pressure in filter chamber 18 reaches a certain value, 25 pounds per square inch in a preferred embodiment, it is time to regenerate filter cake 82.To do so pump 40 is stopped, valve 46 is positioned in it second state, valve 52 is placed in its second state, and surge valve 58 is opened, or placed in its second state. Pump 40 is started and valves 48 and 50 are caused to change states substantially in unison from their second states to their first states, thence back to their second and so forth for several cycles. When valves 48 and 50 are in their sec¬ ond states, liquid from pump 40 flows through filtrate pipe 51 into filtrate chamber 20, then into the hollow interiors of filter tubes 26 and through the screens 36 of such tubes into filter chamber 18. Figure 5 schematically illustrates the flow of liquid through the screen 36 of a filter tube 26 during such a period of reverse flow. When valves 48 and 50 are in their first states, fluid from pump 40 flows into filter chamber 18 through filter in¬ let pipe 40, the normal direction, of flow of liquid. Liquid in chamber 18 can flow out of chamber 18 through surge line 56 and through the filter tubes into filtrate chamber 20 and thence into precoat tank 44. The normal direction of flow of liquid through a filter tube is schematically illustrated in Figure 6. 'During the regeneration cycle the direction of flow of liquid through the filter tubes is changed rapidly which causes the liquid to oscillate or surge through the filter tubes to liquidize the filter cake 82 and the solids re-'BϋREΛTOMPI moved from the filtrate and to mix them with the liquids in the filter chamber so that the solids removed from the filtrate are substantially uniformly distributed, or mixed, with the filter material. The net amount of liquid flow during the regeneration cycle is small because of the oscil lating nature of the flow and because the entire regenera¬ tion cycle requires only a short time to accomplish its pur pose, on the order of one minute. The period of oscillatio in a preferred embodiment is in the range of from 2 to 20 seconds, the preferred period being from 4 to 10 seconds. The number of cycles is in the range from 2 to 5, with the preferred number being 3. After the filter cake and remove solids are liquidized and substantially uniformly mixed, valves 48 and 50 are placed in their first states and the filter system is in its precoat cycle so that the filter material with the solids, or impurities, are deposited on the filter tubes and the filter cake 82 is reformed with th impurities substantially uniformly distributed throughout the cake as seen in Figure 7. When the liquid flowing through the sight glass 60 is clear, filter system 10 is ready to go back on stream.As the solids removed from the filtrate during produc¬ tion again build up on the outer surfaces of filter cake 82, the pressure in chamber 18 increases. When it reaches the designated limit, in a preferred embodiment, 25 pounds per square inch, it is again time to regenerate the filter cake as described above. Once the filter cake is liquidized and substantially uniformly mixed with the solids removed from the filtrate, the cake can be reformed as set forth above and the filter system put back on stream, or in production. The filter cake can be regenerated many times in this way, but finally it will be so full of impurities, dirt or solids, removed from the filtrate that further efficient filtration is impossible. Then it is time to remove the impurities and filter material from the filter tubes 26 by λ> liquidizing them and mixing them with the liquid in the filter chamber 18 as described above. Pump 40 is stopped, valve 48 is put in its second state, shut off valve 62 is closed and valve 50 is placed in its first state which iso- lates filter chamber 18 and filtrate chamber 20 from the rest of the filter system 10. Sludge valve 74 is opened and air valve 70 is opened to force the liquid, dirt and filter material from filter chamber 18. After all the sludge and liquid from chamber 18 has been removed, the sludge valve 74 and air valve 70 are closed. The operation of the filter system is ready for the full cycle from filling the filter to precoating the tubes to production to regeneration, etc. All the valves used in the filter system can be pneu¬ matically or electrically powered or controlled instead of being manually controlled. When so controlled all the cy¬ cles, filling, precoating, operating, regenerating, and backwashing can be controlled and programmed by conventional control systems. Since such control systems form no part of this invention, they are not illustrated or further de- scribed.From the foregoing it is clear that this invention pro¬ vides methods, and apparatus for regenerating the filter cake of a liquid filter system by inducing oscillations in the liquid in the filter chamber which liquidizes the filter ma- terial of the filter cake and the solid material removed by the filter cake, substantially uniformly mixes them, and re¬ forms the filter cake with the solid material substantially uniformly distributed through the filter cake.It should be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention. | CLAIMS1. The method of regenerating filter cake formed by depositing small particles of a filter material from a sus¬ pension of said material in a vessel substantially filled with said liquid of a filter system by causing the liquid o the suspension to flow in a forward direction through a porous filter element, comprising the steps of:(a) causing the liquid in the vessel to reverse the direction of flow through the porous filter elemen for a number of cycles in the range of from 2 to 5, each cycle having a time period in the range of from about 2 to 20 seconds; and(b) causing the liquid in the pressure vessel to flow steadily in the forward direction to reform the filter cake on the porous surface of the filter elemen of the system in order to re-establish the filter cake which now is a homogeneous mixture of the filter mate¬ rial and the filtered solids which provides a clean, regenerated outer filtering surface.2. The method of Claim 1 in which the filter material is diatomaceous earth.3. The method of Claim 2 in which the liquid is water.4. The method of Claim 3 in which the number of cycles of flow reversal of the liquid is three.5. The method of Claim 4 in which the preferred range for the time period of a complete oscillation is from 4 to10 seconds.6. The method of regenerating diatomaceous earth ilte cake formed on a filter tube mounted in a filter chamber of a filter system for filtering a liquid which is forced to flow through the filter tube in a forward direction to form the filter cake on the filter tube and to filter the liquid, comprising the steps of:(a) causing the liquid in the system to flow• . through the filter tube in a reverse direction opposite to its forward direction for a first suitable time period;(b) causing the liquid in the system to flow through the filter tube in its forward direction for a second suitable time period; (c) repeating steps (a) and (b) for a number of cycles whereby the particles of the filter cake are liquidized and substantially uniformly mixed with the filtered solids; and(d) causing the liquid to flow in its forward di- rection to reform the filter cake on the filter tube so that the filter cake is a homogeneous mixture of the filter material and filtered solids with a clean outer regenerated filter surface.7. The method of Claim 6 in which the liquid is water.8. The method of Claim 6 in which the preferred number of reverse cycles is 3.9. The method of Claim 6 in which both suitable time periods range from 2 to 5 seconds.10. Apparatus for a pressure filter system for regen¬ erating filter cake formed by depositing small particles of a filter material from a suspension of said material in a liquid on a surface of a porous filter element in a pressure vessel by causing the liquid of the suspension to flow in a forward direction through the porous filter element, com¬ prising:(a) means for causing the liquid in the pressure vessel to cycle between a reverse and forward flow direction through the porous filter element for a plur-I UREΛTΓOMPI A WIPO ality of cycles so that the filter cake is broken up, liquidized and mixed with the residual filtered solid and(b) means for causing the liquid mixture in the pressure vessel after the cyclic operation to flow steadily in a forward direction to reform the filter cake with the mixed filter material and filtered soli on the porous surface of the filter element of the sy tem so that a regenerated clean filter surface is pro duced to renew the efficiency of the filter system.11. A filter system for liquids comprising:(a) a pressure vessel having a dome, the walls o the pressure vessel forming a pressure chamber and th walls of the dome forming a filtrate chamber;(b) a plurality of hollow rigid filter tubes mounted in the filter chamber with the hollow interio of each filter tube in connection with the filtrate chamber;(c) a pump for pumping liquid through the filter system;(d) fluid conductor means connected between the outlet of the pump and the filter chamber, said fluid conductor, means having two conditions, a first condi¬ tion in which fluid from the pump flows into the fil¬ trate chamber only and a second condition in which fluid from the pump flows into the filter chamber onl and(e) surge conductor means which permits a small amount of liquid to flow from the vessel when the flu conductor means is in the first condition; (f) whereby by rapidly changing the flow conditi of the fluid conductor means, cyclic flow of the liuq through the filter tubes can be induced, the period a number of cycles being determined by the rate and num ber of changes, of the flow conditions of said fluid conductor means. -15-12. A pressure filter system for filtering solids from liquids comprising:(a) a pressure vessel;(b) a pressure dome removably mounted on the pres¬ sure vessel, the interior of the pressure vessel form- ing a filter chamber, the interior of the pressure dome forming a filtrate chamber;(c) a plurality of rigid filter tubes, each tube having a porous wall with a hollow interior and adapted to have a filter cake of filter material formed thereon by action of a slurry of the material and liquid as the liquid flows through the porous walls of the filter tubes;(d) means for mounting the filter tubes in the filter chamber so that the hollow interior of each filter tube is in communication solely with the filtrate chamber, said means for mounting also separating the filter chamber from the filtrate chamber so that fluid can flow from the filter chamber to the filtrate chamber only through the filter tubes; (e) pump means having an input port and an output port;(f) a precoat tank;(g) first liquid conductor means including first valve means having a first and second state for connect- ing the input port of the pump means to a source of liquid to be filtered when the valve means is in its first state and to the precoat tank when the valve means is in its second state;(h) second liquid conductor means including second valve means having a first and a second state for con¬ necting the output port of the pump means to the filter chamber when the second valve means is in its first state;(i) -third liquid conductor means including third and fourth valve means, each of the valve means having two states, for connecting the filtrate chamber with the precoat tank when the third valve means is in its first state and the fourth valve means is in its secon state;(j) surge liquid conductor means and fifth valve means having a first and second state, for connecting the filter chamber and the precoat tank when the fifth valve means is in its second state; and(k) fifth liquid conductor means for interconnect ing the second and third conductor means so that the output port of the pump means is connected to the fil¬ trate chamber when the second and third valve means ar in their second states; whereby flow reversal of the liquid through the filter tubes to regenerate the fil¬ ter cake can be induced by rapid change of the states of the second, third and fifth valve means from their first to their second and then back to their first states substantially in unison and for a plurality of cycles to liquidize and mix- the filter material and filtered solids and regenerate the filter cake on the filter tubes to restore the efficiency of the filter system.13. The filter system of Claim 12 in which the walls of the filter tubes are formed of a fine wire mesh.14. The filter system of Claim 12 in which the filter material is diatomaceous earth.15. The filter system of Claim 12 in which the liquid is water. I AMENDED CLAIMS(received by the International Bureau on 12 January 1979 (12.01.79)) <-1. A method for use in a liquid type filter vessel having at least one filter tube for regenerating the filter cake medium on the filter tube within the vessel, said filter cake being formed by introducing a suspension of a liquid and small particles of filter material into said vessel so that when the liquid passes through the filter tube in a forward flow direction, the filter material will be deposited thereon to provide the filter medium for a continuous liquid filtering process, the regenerating method comprising the steps of(a) reversing the flow of a sufficient quantity of liquid through the filter tube for a sufficient time to dislodge the filter cake and retained solids from the filter tube;(b) causing the liquid within the vessel to move in a cyclic forward and reverse flow direction within the vessel to break up the filter cake formed by the particles of filter material and mix the particles and the retained solids to form a homogeneous liquidized suspension within the vessel; and(c) redepositing the mixture of the filter material and retained solids on the surface of the filter tube in order that the regenerated filter cake will be homogeneous through- out its thickness and will have a clean filter surface to improve the efficiency of the liquid filtering process.2. A method for regenerating the filter cake in a liquid-type filter vessel, said filter cake which is the filter medium for the separation of solids from the liquid during the filtering process being formed by depositing a layer of filter material on the surface of a filter element within the vessel by passing a liquid suspension of said material in a forward flow direction through said vessel so that the liquid passes through the filter element leaving the filter cake formed on the surface of the said filter element, the regenerating method comprising the steps of(a) reversing the flow of liquid through the filter element and vessel with a sufficient flow quantity and for a sufficient time to dislodge the filter cake and retained solids from the filter element,(b) cycling the flow of liquid within said vessel in a forward and reverse flow direction a sufficient number of cycles and time period to break up and mix the filter material and retained solids forming a homogeneous liquidize suspension within the vessel; and(c) flowing the liquid suspension in a forward flow direction so that the liquid again passes through the filter element leaving the filter material and retained solids as a homogeneous filter cake on said filter element whereby the regenerated filter surface of the cake is sub¬ stantially free of solids to improve the efficiency of the filtering process.3. The method of Claim 2 in which the filter material is diatomaceous earth.4. The method of Claim 2 in which the liquid is water.5. The method of Claim 2 in which the number of cycles for complete flow reversal of the liquid within the vessel during the cycling step is at least three.6. The method of Claim 2 in which the time range during the cycling step for complete flow reversal mixing is within the range of four to ten seconds.7. The method of Claim 2 which further includes the step of removing a quantity of liquid from the filter vessel equal to the quantity of liquid used in the first flow re- versal so that the dislodged filter cake will move substan¬ tially away from the filter element into the interior of the filter vessel for the cycling step.8. The method of Claim 2 in which the filter element is one or more filter tubes.9. A method for regenerating the filter cake in a liquid-type filter system, said filter cake being formed by depositing a layer of a filter material on the surface of a filter element within said system as the liquid passes in a forward flow direction through the filter element, the filter cake being used to continuously filter solids from the liquid during a filtering process, the regeneration method comprising the steps of(a) reversing of the flow of liquid through the filter element for a sufficient time and with a sufficient quantity to completely dislodge the filter cake and retained solids from the filter element;(b) cycling the flow of liquid within the filter system from the forward direction to the reverse direction for a sufficient number of cycles and time period to thorough¬ ly break up and mix the filter material and retained solids into a homogeneous suspension in said liquid;(c) redepositing the suspension of filter material and retained solids in a homogeneous filter cake which will have a clean outer surface to improve the efficiency of the filtering process; and(d) flowing liquid in the forward filtering direction until such time that the efficiency of the filtering system drops below a predetermined level caused by subsequent retained solids at least partially blocking the outer surface of the filter cake; and repeating steps (a) , (b) , and (c) periodically as needed to continue the useful life of the original filter material in the filter system for an extended period of time.OMPI _^ WIPO 10. A method for regenerating the filter cake in a filter system as described in Claim 9 which further includes the step of disposing of the filter material and retained solids from said filter system when the quantity of solids retained in the filter material reaches a predetermined pro¬ portion wherein the filter process is no longer economically efficient.11. A filter system for liquids comprising a filter regeneration system, said filter regeneration system com- prising:(a) first and second path means:(b) said first path means comprising in sequence: pump means, first conduit means, first valve means, second conduit means, first filter housing nozzle means, filter element means, second filter housing nozzle means, third conduit means, second valve means, and fourth conduit means;(c) said second path means comprising in sequence: • said pump means, said first valve means, fifth conduit means, said second valve means, said third conduit means, said second filter housing nozzle means, said filter element means, third filter housing nozzle means, and sixth conduit means; and(d) said regeneration system further comprising me to alternate flow between said first and second path means in a frequency and duration sufficient to liquify and homo- geneously mix a filter cake which was on the surface of said filter element means; and(e) said filter system further comprising means to redeposit said liquified filter cake upon the surface of sai filter element means as a single homogeneous layer. 12. Apparatus for a pressure filter system for regen¬ erating filter cake formed by depositing small particles of a filter aid material from a suspension of said material in a liquid on a surface of a porous filter element in a pressure -vessel by causing the liquid of the suspension to flow in a forward direction through the porous filter element, com¬ prising: means for causing the liquid in the pressure vessel to cycle between a reverse and forward flow direction through the porous filter element for a plurality of cycles so that the filter cake is broken up, liquidized and mixed with the residual filtered solids; and means for causing the liquid mixture in the pressure vessel after the cyclic operation to flow continuously in a forward direction to reform the filter cake with the mixed filter aid material and filtered solids on the porous surface of the filter element of the system so that a regenerated clean filter cake surface is produced to renew the efficiency of the filter system.13. The filter system of Claim 12 in which the filter material is diatomaceous earth.14. The filter system of Claim 12 in which the liquid is water.fa wipo STATEMENTUNDERARTICLE19In accordance, with the Notification of Transmittal of the International Search Report in the above-identified International Application mailed 16 November, 1978, please amend this application as follows:In the Specification, substitute the new Page 9 in¬ cluded with this Amendment for the original Page 9 in the original application as filed.Delete Pages 12, 13, 14, 15, and 16 which contain the claims in the original application as filed and substitute the new Pages 12, 13, 14, 15, and 16 which now present a new set of claims in this application.REMARKS< rThe substitution of the newly typed Page 9 in this application is provided in order to correct two typographica errors that were noted in the original page as filed. In Line 27 (old page) , the number 40 has been changed to 49 to correct the designation for the filter inlet pipe . In Line 29 (old page) , and has been changed to or so that the phrase now reads through surge line 56 or through the filter tubes... . These two changes are the only changes made on this page.All of the claims of the original -application which were contained on the old Pages 12-16 have been deleted bythis Amendment and fourteen new claims on new Pages 12-16 have been substituted. Of the new claims, Claims 1-10 are method claims directed to the process for regeneration of the filter cake within the liquid filter. Claim 11 is an apparatus claim directed to the structure for regenerating the filter cake in the novel filter system. Claims 12-14 ar directed to the broad concept of the apparatus for a system having the capability of regenerating the filter cake. These new claims are provided to place the application so that it now corresponds with the claims presently pending i the corresponding United States Patent Application, Serial Number 822,133.The cancellation of the original claims and substituti of the new claims by this Amendment is believed to place this application in better condition for allowance. The claims as now presented are believed to better define the Applicant's invention in more clear and concise terms to properly describe and claim the apparatus to which the Applicant is entitled. The original claims were cumbersome and therefore it is felt necessary to rewrite and substitut these new claims.The claims as now presented are believed to be patenta nd the aoolication as amended is in condition for allowanc | ENVIRONMENTAL IND PROD; ENVIRONMENTAL IND PROD INC | MUTHER R |
WO-1979000096-A1 | 1,979,000,096 | WO | A1 | EN | 19,790,308 | 1,979 | 20,090,507 | new | G11C11 | null | G11C11, G11C13 | G11C 13/04E | OPTICAL MEMORY WITH STORAGE IN THREE DIMENSIONS | A high storage capacity, fast access time, photovoltaic ferroelectric memory apparatus including a plurality of memory planes (1) which are stacked in a three dimensional configuration. Each plane is comprised of a photovoltaic ferroelectric layer (9) and a photoconductive layer (10) sandwiched between two electrodes (8), (11). Writing of information is effected by illuminating a selected xy location on the planes while simultaneously applying a voltage pulse to a selected z plane, and reading is effected by illuminating a selected xy location while connecting a selected z plane to a read amplifier. | TITLE: OPTICAL MEMORY WITH STORAGE IN THREE DIMENSIONSBACKGROUND OF THE INVENTION T he present application claims priority from its earlier filed U.S. Application Serial Number 824,895, filed 15 August, 1977 and, is related to U. S. Patent Application No. 533,365, filed on December 16, 1974, in¬ corporated herein by reference, which is in turn a con- tinuation-in-part of U. S. Patent No. 3,855,004, also in¬ corporated herein by reference.The present invention is directed to a high storage density, fast access time random access memory having a three dimensional configuration.As is known, a random access memory is one which permits information to be instantaneously either written into or read out of any selected storage position of the memory. This is in distinction to a serial memory such as magnetic tape, where a selected position can be arrived at only by unreeling the tape to the desired position. While memories such as magnetic tapes are capable of storing large amounts of information, the serial mode of access is much too slow to be directly useful in the real time operations which are performed by a computer.Presently, the most widely used random access memory is the magnetic core memory wherein storage is in a row and column arrangement of magnetic cores which are accessed by a matrix arrangement of wires. While the magnetic core memory has found wide usage in computer technology, it is limited both as to storage capacity and rapidity of accessing time. Therefore, in recent years, a great deal of expense and energy has gone into attempting to develop a better random access memory, that is, one with a very large storage capacity, and a very fast accessing time. While memories which have a larger storage capacity than magnetic core memories have been developed, at least some of these have the disad¬ vantage of being volatile, that is, the stored data is lost if the power to the memory or to the computer is cut off. It is therefore an object of the invention to provide a random access memory having a high density storage capability.It is a further object of the invention to pro¬ vide a random access memory having a fast accessing time. It is still a further object of the invention to provide a memory which is capable of storing gray scale information.It is still a further object of the invention to provide a memory which allows data to be transferred in and out at high rates.It is still a further object of the invention to provide a random access memory which is non-volatile. It is still a further object of the invention to provide a random access memory which is non-destructive. The above objects are achieved by providing a memory which utilizes photovoltaic ferroelectric material as the storage medium. For a detailed discussion of the properties of these materials as well as typical mater¬ ials which can be used, the reader is referred to the above-mentioned patent and patent application. Briefly,OM photovoltaic ferroelectric materials, which include ferroelectric ceramic materials, if remanently polar¬ ized, will produce a voltage output upon being illumin¬ ated. The polarity of the voltage output corresponds to the polarity of the remanent polarization, and its magnitude is proportional to the magnitude of the re¬ manent polarization and to the length of the material.In accordance with the invention, a plurality of two dimensional photovoltaic ferroelectric memory planes are stacked to provide a three dimensional configuration. Each memory plane by itself, provides a high density storage capability, and this capability is increased by orders of magnitude by the three dimensional stacking. Both write in and read out are primarily optical, which allows fast accessing times. And, according to the arrangement disclosed, accessing a plurality of stacked memory planes should not take any longer than accessing a single memory plane, so that increased storage capa¬ bility is achieved without an increase in the accessing time.The invention will be better understood by re¬ ferring to the accompanying drawings in which:Figure 1 is a generalized block diagram of the random access memory apparatus of the invention. Figure 2 is a cross-sectional view of a segment of a memory plane.Figure 3 is a perspective view of a segment of a memory plane.Figure 4 is a cross-sectional view of a segment of a memory plane in a region of a cavity thereof, and also shows the optical diffuser/reflector block at the end of the cavity.Figure 5 is a cross-sectional view of a stacked array of memory planes.OMPI Figure 6 is a perspective view of a stacked array of memory planes.Figure 7 is a perspective view of a fiber optic image recording station utilizing the principles of the present invention.Figure 1 is a block diagram of the general organ¬ ization of the memory apparatus of the invention. It is comprised of memory block 1 which is a stacked array of photovoltaic ferroelectric layer-photoconductive layer memory planes to be described in greater detail below. Each memory plane is connected to electrical switching network 5 by conductors 20. Beam deflector 3 and lens 4 are disposed with respect to laser 2 so as to deflect the laser beam to any xy memory position of the memory plane.Generally, in order to write information into the memory cell by cell, the beam is deflected to a selected cell at a position Xi, Yj, on the image plane while simultaneously electrical switching network 5 con- nects the electrodes of a selected memory plane Z. to write pulse generator 7. Accordingly, the information is recorded into the selected cell x., Y., z . Pre--• 3 k ferably, as will be explained below, the write pulse generator includes a subsidiary pulse generating means for generating an opposite polarity pulse following the write pulse. As will be appreciated, the design of such multiple pulse generators is within the knowledge of those skilled in the art.To read, the beam is deflected to a selected one 2 of the N cells on the image plane while simultaneously electrical switching network 5 connects the conductors from a selected memory plane Z to the read amplifier 6.It should be understood that both the laser beam deflector system and the electrical switching network 5 are known to those skilled in the art, and form no partITURO of the present invention. Thus, for example, two di¬ mensional beam deflector 3 may comprise a type of electro-optical beam deflector while electrical switch¬ ing network 5 may comprise a solid state switching array. The structure of memory block 1 is shown in greater detail in Figures 2 through 6.Figure 2 is a cross-sectional view of a segment of a single memory plane while Figure 3 is a perspective view of a section of the memory plane. As shown, each memory plane is comprised of photovoltaic-ferroelectric layer 9, juxtaposed with photoconductive layer 10, and sandwiched between electrodes 8 and 11. Conductors 20 are attached to the electrodes for connection to electri¬ cal switching network 5. The photovoltaic-ferroelectric material may be any of a number of ferroelectric ceramic materials, and for greater detail in this regard, the reader is reffered to the above-mentioned patent appli¬ cation and patent. An example of the material which may be used is PZT-5A. As shown in Figures 2 and 3, each of the memory2 planes is perforated by N individual cylindrical hollow cavities. Each of these cavities comprises a memory cell and each is disposed at a different xy location on the plane. Photoconductive layer 10 is comprises of a mater¬ ial having a high dark resistance, and preferably a low dielectric constant. Examples are organic photoconductors or zinc oxide prepared with high dark resistance. While the dimensions of the memory plane can be varied to suit individual requirements, as an example, the lateral di¬ mension may be of the order of 1 centimeter, the thick¬ ness may be of the order of .1mm or less, and the dia¬ meter of the individual cavities may be of the order of .025 mm. Each plane described can operate individually as an isolated memory medium as well as a member of a ' stacked three dimensional configuration. Operation of the stacked configuration will be more easily under¬ stood once operation as an isolated unit is described. Referring to Figure 4, the laser beam is focussed within the cavity which defines the memory cell. The light scatters off the cavity sidewalls and the reflecting- diffusing optical stop 15 which closes the end of the cavity. While not shown in the Figure, the light act- ually bounces off the sidewalls many times after being reflected back through the cavity by block 15. For even moderate depth to diameter ratios, there will be a light trapping action and the illuminated walls will absorb the light in an optical absorption depth (s) which will generally be somewhat different for the two different materials which comprise the cavity. Simultaneously with the illumination, a voltage pulse is applied across the electrodes of the memory plane by the pulse generator. The effect of the illumination in the photo- conductivity thereby allowing sufficient current to flow through the illuminated wall region to switch a portion of the remanent polarization P in the light absorbing region of the photovoltaic-ferroelectric material. The final magnitude and polarity of the polarization is de- , pendent on the magnitude and polarity of the voltage applied, the magnitude of the current that is flowing and the duration of time for which it flows, and the initial state of remanent polarization within that region.If there was no initial polarization within the region, there is now remanent polarization in the walls of the cavity parallel to the cylindrical axis. There is no remanent polarization in the remaining cavities since simultaneous illumination and application of a voltage has not occurred. However, due to the dark current of the photoconductive material, it is possibleO that under certain conditions, a relatively small switch¬ ing of remanent polarization will occur in the walls of non-illuminated cavities. Although insignificant during a single write in, after a great number of write ins, this effect can interfere with proper operation.To minimize this effect after the illumination • is removed, a pulse of polarity opposite to that of the initial pulse is applied to the memory plane. This opposite polarity pulse is of sufficient magnitude to remove the small remanent polarization induced in the originally dark cells. The remanent polarization in the cell which was illuminated also may be somewhat reduced in magnitude, but the result of the operation is a net remanent polarization the photovoltaic ferroelectric portion of the cell which was illuminated with essential¬ ly zero remanent polarization in the remaining cells. It should be noted that while the ferroelectric material is illuminated in the above-described arrangement, this is not necessary for write in, remanent polarization being effected even if the ferroelectric is not illumin¬ ated or is illuminated by a wavelength which does not produce significant photoconductivity in the ferro¬ electric. To read information out of the memory block, a cavity is illuminated, and the output of the read ampli- fier is connected across the electrodes. The read ilium-. ination induces a current proportional to the magnitude of the remanent polarization which charges the total capacity across the amplifier input. This capacity is primarily the capacity between the memory plane electrodes and it is charged through the low resistance provided by the illuminated photoconductive region of the cylinder wall. The photovoltaic ferroelectric source acts init¬ ially as a constant current source charging the capacity C to a voltage V = ~-~i~-ϊ—t in time cJt, the voltage appear- ing across the input of, for example, an FET operational amplifier. The voltage eventually rises to a maximum value equal to the open circuit emf of the photovoltaic- ferroelectric segment which is VQd, where VQ is the open circuit voltage per unit length, and d is the length of a photovoltaic-ferroelectric cavity. For PZT- 5A, the constant, VQ has a value of about 60 millivolts per micrometer.An essential element of the present invention is the simultaneous accessing for both writing and read- ing of a plurality of stacked three dimensional planes. This enables accessing of a large number of stacked planes in the same time as it would take to access a • single plane. While the cylindrical cavity arrangement described is effected with particular convenience and advantages, the invention is not limited to this embodi¬ ment. Further, it should be appreciated that the type of memory disclosed has advantages over systems using various techniques including photoconductive switching to effect remanent polarization for changing the light transmission properties of an element. .Such memory does not lend itself to three dimensional stacking be- • cause of the resultant superposition and confusion, of read information. It should be further noted that while not as effective for read-out, instead of the photo- voltaic effect produced by illumination, the pyroelectric current produced by selective heating may be used. It may also be possible to use other transient currents which are proportional to the remanent polarization for read out. The photoconductive region serves two purposes.Firstly, as a photoconductive switch which allows polar¬ izing of selected cells, and secondly, as. a contact -point which connects the region in which the read signal is generated to the capacitor formed primarily by the plate electrodes. This capacity is much reduced from the capacity of a parallel plate capacitor which would be formed by the plates were they to directly cross the photovoltaic-ferroelectric layer, the dielectric con¬ stant of which is of the order of 1,000, since the photovoltaic material typically would have a dielectric constant of about 10. The arrangement thus enhances the magnitude of an initial read signal, as can be seen from the above equation.Reading can also be accomplished with the use of a current sensing amplifier instead of a voltage sensing amplifier.With the arrangement shown in the drawings, experimental results indicate that relatively fast read and write times can be obtained. Additionally, by making the cylinders diameters as well as the distances be- tween cylinders relatively small, a high packing density can be obtained. This high packing density can be in¬ creased by orders of magnitude by stacking the memory plates to form a three dimensional configuration. Thus, large numbers of plates can be stacked to increase the storage density many times without increasing the read- write access times.The .three dimensional configuration is effected by stacking a plurality of plates with the cylindrical cavities in register, and adding a multiple switching circuit which allows a selected sequential pair of electrodes to be selectively connected to the write pulse generator for the write operation and to the read amplifier for the read operation. As shown in cross- section in Figure 5 and in perspective in Figure 6, a plurality of memory plates 17, 18, etc. are stacked together with the individual plates being connected to switching network 19. Multiple diffuser-reflector block 16 is disposed at the end of the composite cavi¬ ties. To write, the beam is deflected to a cell en- trance x, y. The light which is trapped illuminates the inside of a long hollow cylinder comprises of the individual cylindrical memory cells between the elec¬ trodes bounding the planes. Information is stored in any one of the cells, x.,y.,z by illuminating the cylinder entrance x.,Yj»and switching the electrodes across the plate z. to the write pulse generator which applies the poling voltage pulse and the subsequent clean-up pulse with illumination removed. To read, cell x., Y. is illuminated, and the electrodes of plane z are switched to the amplifier input.Further, it is clear that a continuous tone image which is projected upon the cylinder entrances can be stored in one polarizing operation in any of the stacked plates. It can be removed by electrical de-poling, or by re-poling to a uniform polarization state. As shown in Figure 7, such an image could enter by way of fiber optic lines 21.While in the multiple plane system described above, readout is normally point by point with random, or if desired, sequential access for data transfer pur¬ poses, higher rates can be achieved by transferring out data in parallel into K read amplifiers simultan¬ eously from K plates. Similarly, K pulse generators can be used for writing in parallel. Since the output current of an illuminated cell is proportional to both the illumination intens¬ ity I and the remanent polarization in the cell P , the memory can be used to compute the product of these two quantities. An intensity modulated beam can be utilized to produce (I) and where is the product,f^= A .cf(I) γ (Pr) .It should be understood that while the Figures show a read-write ferroelectric photovoltaic memory,OM - li ¬the teachings of the invention are also applicable to a read only memory in which the photoconductive layer would be dispensed with. The remanent polarization in¬ formation could be entered by a direct polarization technique, by replication, or by any other method known to those skilled in the art.I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications can be made by a person skilled in the art. | THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED AND DEFINED AS FOLLOWS:1. A three dimensional memory apparatus, com¬ prising, a plurality of electrically switchable stacked memory planes, each memory plane including a layer of photo¬ voltaic ferroelectric material and a layer of photo¬ conductive material, means for generating a light beam, means for optically addressing selected stor¬ age x-y locations of the memory planes with said light beam, and means for simultaneously electrically switch¬ ing to a selected memory plane, whereby the selected x-y locations on the selected plane are accessed for writing and/or reading.2. The apparatus of claim 1 wherein each memory plane further comprises, a sandwich of said layer of photovoltaic ferro¬ electric material and said layer of photoconductive material between two electrodes, and, said means for electrically switching being connected to said electrodes.3. The apparatus of claim 2 wherein said memory planes have a plurality of cavities therein, each cavity extending fully through the memory plane and comprising said storage x-y location.4. The apparatus of claim 3 wherein said memory planes are stacked with the cavities of the respective planes being lined up with each other. 5. The apparatus of claim 4 further comprising, means for writing information into said memory, said means for writing comprising, means for applying a first electrical pulse to said selected memory plane, whereby due to the photoconductivity of said photoconductive layer a greater portion of the magnitude of said pulse appears across said selected x-y locations than across non-selected locations, thereby inducing a remanent polarization in the ferroelectric of said selected locations.6. The apparatus of claim 5 further including, means for applying a second electrical pulse opposite in polarity to said first electrical pulse immediately following said first electrical pulse, the magnitude of said second pulse being substantially smaller than the magnitude of said first pulse.7. The apparatus of claim 5 further including, means for reading which includes means for connecting said selected memory plane to a read amplification means.8. The apparatus of claim 5 further including, a light diffuser-reflector means disposed at the end of each composite cavity which is formed by the juxta¬ position of the adjacent cavities, of the adjacent stacked memory planes.9. The apparatus of claim 3 for accessing a plurality of cavities at the same time, comprising a light conducting element disposed to pass in, through, and out of each of said plurality of cavities.10. A memory apparatus comprising, a memory plane comprised of a layer of photo¬ voltaic ferroelectric material and a layer of photo¬ conductive material sandwiched between two electrodes, said plane having a plurality of information storage cavities therein, each cavity passing entirely through said memory plane, and, means for addressing a selected cavity with a light beam, and, means for simultaneously applying a voltage pulse across said electrodes, whereby information is written into said selected cavity.11. A method for determining the product of two quantities, utilizing the apparatus described in claim 7, comprising the steps of, making the intensity of said light beam pro¬ portional to one of said quantities, making the magnitude or duration of said elec¬ trical pulse proportional to the second of said quanti¬ ties, optically addressing a selected cavity with said light beam, applying said pulse to a selected memory plane, and, detecting the output current of said selected cavity in said selected plane, which current corresponds to said product.12. A three dimensional photovoltaic ferro¬ electric memory apparatus, comprising, a plurality of electrically switchable stacked ferroelectric memory planes, each memory plane including a layer of photo¬ voltaic ferroelectric material, means for generating a light beam, means for optically addressing selected storage x-y locations of the memory planes with said light beam, and means for simultaneously electrically switching to a selected memory plane, whereby the selected x-y locations on the selected plane are accessed for reading. | PHOTOVOLTAIC CERAMIC CORP; PHOTOVOLTAIC CERAMICS CORP | BRODY P |
WO-1979000097-A1 | 1,979,000,097 | WO | A1 | XX | 19,790,308 | 1,979 | 20,090,507 | new | G11C11 | null | G11B9, G11B11, G11C14 | G11B 11/08, G11B 9/02, G11C 14/00 | PHOTOVOLTAIC-FERROELECTRIC DATA RECORDER | A data recording and read-out apparatus and method in which a ferroelectric ceramic substrate (5) is remanently polarized to store information. Upon being illuminated, the substrate produces a photovoltaic voltage, which is detected to effect read-out. A disk (1) of ferroelectric ceramic material (5) to which information is entered by spiral tracking, either in a single track or in multiple tracks. A self-scanning data record comprised of a plurality of ferroelectric ceramic cells (20) which are remanently polarized, and which are read out by a register (22). | TITLE : PHOTOVOLTAIC-FERROELECTRIC DATA RECORDERBACKGROUND OF THE INVENTIONThe present application claims priority from the U.S. Patent Application 324,894, filed August 15,1977 and is related to U.S. Patent Application No. 533,365, filed- December 16, 1974, incorporated herein by refer¬ ence, which in turn is a continuation-in-part U.S. patent No. 3,855,004, also incorporated herein by refer¬ ence.As disclosed in the above-mentioned patent and patent application, the inventor has discovered that the class of materials known as ceramic ferroelectrics, if remanently polarized, will produce a photoelectric voltage upon being illuminated. The reader is referred to the above-mentioned patent documents for the details of this phenomenon, but briefly, the voltage output of the material is of a polarity corresponding to the direction of the re anent polarization and is of a mag¬ nitude proportional to both the amplitude of the lemanent polarization and the length of the ferroelectric material, The present invention in its broadest aspect is directed generally to a data recording and readout apparatus and method employing the above phenomenon, and BUREAU.. O PI in its more specific aspects, is directed to a disk recording and readout apparatus and a self-scanning data record.■ In general, one of the advantages of the inven-•5 tion is that it provides a storage and retrieval device which affords both relatively high density storage and a relatively fast accessing time.The disk recording apparatus provided by the present .invention possesses advantages over prior art10 disk systems. By way of background, disk recording and readout systems in general have been known for many years and are most frequently found in the well known vinyl phonograph disk which is both cut and read-out by mech¬ anical as opposed to electrical or optical means. Be-15 cause of the inherent limitations of the mechanical mode, conventional record disks have been limited as to the density of* information which can be stored, and addition- _ ally have the disadvantage of becoming scretched or damaged by wear.20 While magnetic tape has supplanted vinyl disks to a certain extent, especially where high quality audio reproduction, and video reproduction is desired, tape too is susceptible to surface wear, and has the further significant disadvantage that it must be replicated by25 recording rather than by a contact replication process, such a*s is used in the case of vinyl disks. This accounts for the higher price of magnetic tapes.For several years,, there has been an effort to develop a charge deposition or capacitive recording30 system in which charge is deposited directly on the sur¬ face of an insulating tape, which acts like a capacitor. The pickup in this type of system is a non-contacting probe which tracks the tape. The advantage of this system is that it affords higher density than the vinyl disk,35 and in comparison to conventional magnetic tape, can afford a large number of tracks. However, the problem isO that the charge is not permanent and leaks off over a period of time, and this is probably why such systems have not been commercialized.In distinction to the above, the present invent- ion provides a disk made of a ferroelectric ceramic material which is recorded by being remanently polarized within its bulk by a polarizing electrical signal, and which is read-out by the detection of a photovoltaic out¬ put voltage which is produced when the disk is illumin- ated. This sytem affords a unique combination of charac¬ teristics and advantages not found in the prior art. Since it provides a high density storage capacity, more information can be stored and a correspondingly higher bandwidth can be obtained than with either the vinyl, disk or magnetic tape, and since the information is stored in the bulk of the material rather than on the surface, there is no wear problem as with conventional disks and tape. Like the charge depositions system the present invention permits the use of a large number of recording tracks, but unlike the prior art system, in- ~ formation storage is permanent as opposed to temporary. Finally, the disk of the present invention, has the signi¬ ficant advantage of being capable of being replicated by a contact process, and further, may permit both re- cording and readout on the same turntable in situations where this may be advantageous.It is thus an object of the invention to provide a new data recording and readout apparatus and method employing a newly discovered phenomenon. It is a further object of the invention to pro¬ vide an improved disk recording and readout apparatus.It is a further object of the invention to pro¬ vide a disk which may be recorded by either digital or analog signals and which may be utilized either as an audio disk or a video disk.-BUREAOMPI rΛ, 1P0 y It is still a further object of the invention to provide a data recording and readout apparatus which is capable of high density storage of information.It is still a further object of the invention to provide a data record which is not subject to the problem of surface wear or damage.It is still a further object of the invention to provide a recording and readout apparatus which can employ a large number of tracks or channels. It is still a further object of the invention to provide a data record which can be easily and inex¬ pensively replicated.It is still a further object of the invention to provide a self-scanning data record. The invention will be better understood by re¬ ferring to. the accompanying drawings in which:Figure 1 is a pictorial illustration of a disk data recording arrangement according to the. invention.Figure 2 is a cross-sectional view of the ceramic ferroelectric disk shown in Figure 1.Figure 3 is a representation of a data playback arrangement according to the invention.Figure 4 is a representation of a multi-channel data recording arrangement according to the invention. • Figure 5 is a representation of a multi-channel data replaying arrangement according to the invention.Figures 6 to 8 are representations of self- scanning arrangements according to the invention.Referring to Figure 1, data is entered into disk 1 by stylus 6 which is on the end of tracking arm 2. Disk 1 is in the shape of a conventional audio disk and as shown in cross-section in Figure 2, is comprised of bottom conducting substrate 4 which is coated with ferroelectric ceramic material layer 5. Coating 5 may be made of any appropriate ferroelectric ceramic material. and for a more detailed discussion of appropriate mater¬ ials, see the above-identified co-pending patent and patent application. As an illustrative example, the material PZT-5 may be used. Data is entered into the sheet by the appli¬ cation of a voltage between a point on the insulating ceramic surface and a conducting plane. The voltage may be applied by using a contacting stylus such as shown at 6, or by an equivalent method, such as by using an electron beam, non-contacting stylus, ion beam, or other method. Access to points on the disk is by spiral tracking as in a conventional audio disk playback unit using a pre-cut groove, a lead screw, or other method to track the input voltage point in a spiral path on the surface of the record rotating beneath the head. The mechanics of such an -arrangement are considered to be well known to those skilled in the art, and are there¬ fore not disclosed in detail in the present application. The exemplary information shown as being entered to the disk in Figure 2 is an arbitrary pattern of alternating remanent polarization directions. It is significant to note that since the magnitude of the remanent polari¬ zation which is produced in a ferroelectric ceramic material is proportional to the amplitude of the voltage applied; analog as well as digital information can be entered into the disk.The playback signal is in the form of a modulated voltage proportional to the remanent polarization appear¬ ing between the conducting substrate and a contacting or non-contacting stylus, moving in the same path as the stylus which entered the data. The playback voltage is produced when the surface of the disk is illuminated by a source of an apprppriate wavelength, and the voltage which is detected results from a charge density ώ(r) which appears on the insulating surface.-BUREAUOMPI An illustrative playback arrangement is shown in Figure 3 wherein the surface of the disk is illumin¬ ated by lamp 19 and the voltage is picked up by con¬ tacting probe 6, and is fed to appropriate amplifica- tion circuitry 7. It is noted that a positive voltage appears at the portions of the disk in which a remanent polarization has been created by a positive polarizing voltage.The illumination used for playback can be con- tinuous, can be turned on just preceding playback or can be peridically applied with sufficient average in¬ tensity to maintain the photo-induced surface charge. For photo-voltaic ferroelectric ceramic materials such as PZT, PLZT, BaTi03, etc., this wavelength is in the deep violet or ultraviolet region, and the wavelength and intensity determines the rate of surface charging. As . an example, lamp 19 may be a conventional fluorescent tube with the phosphor used to produce illumination peaked in the 370 UV region. If a non-contacting stylus is used for playback, it detects a voltage induced by the surface charge den- • sity -s-(r) utilizing a voltage to current converter, and if a contacting stylus is used, the surface charge den¬ sity 6 (r i*3 discharged through the input of a current to voltage converter. In that case, the charge density re-appears rising at a rate defined by a charging time constant f . In either case, the charge density vanishes as a result of leakage when the illumination is removed and the dark discharge time constant -£', is generally much greater than _- . The above allows for continuous playback, even if detection is by the discharge mode.In addition to the photo^voltages described above, pyroelectric voltages generally produced by in¬ cidental heating, for instance due to the illumination, are also present. These are in the same direction as the photovoltages, and thus produce similar effects. The pyroelectric voltages however, are produced by the ther¬ mally induced changes in the remanent polarization, and thus are an increment in the total surface charge, and are not constantly renewed by the illumination or heat. They decay with time as the result of resistive paths to ground, and alone do not provide a suitable source of voltage or charge for playback. For efficient photo- voltage producing radiation, the pyroelectric voltage produced incidently by a temperature increment should be much less.than the photo-voltage.An illustrative embodiment of a multi-channel recording system is shown in Figure 4, and a correspond¬ ing embodiment of a multi-channel playback system is shown in Figure 5. Referring to Figure 4, it is seen - that multi-channel probe assembly 11 has a plurality of information inputting probes 12, and in the drawing,eight channels and probes are shown. At the input, a signal is originated by microphone 8, or other signal source, and is fed to signal compression logarithmic amplifier 9, and from there to analog-to-digitai converter 10, since the illustrated system is digital. The digital signals are then inputted to probe assembly 11, where eight concentric spiral channels are recorded. For playback, as is shown in Figure 5, pickup probe assembly 13 includes eight probes 14, and the sig¬ nals picked up are fed through digital-to-analog con¬ verter 15, anti-log amplifier 16, and power amplifier 17, to speaker 18, or to some other desired output device. Instead of the antilog amplifier, pulse modulation in combination with a Class D amplifier, or other arrange¬ ment known to those skilled in the art, can be used.As mentioned above, one of the advantages of the ceramic disk of the present invention is that it can be-BtTEAlT OΛ-PI replicated by a contact process. For a more detailed discussion of this, the reader is referred to co-pending ϋ. S. Patent Application No. 533,365.Figures 6-8 show additional embodiments of the invention in which an analog or digital data record is self-scanned. Referring to Figure 6, cells 20 are in¬ dividual photovoltaic-ferroelectric ceramic memory cells having remanent polarizations stored therein. Register 22 is a known charge control device register, which as known to those skilled in the art, is analogus in opera¬ tion to a shift register in that charge is moved from one storage position to the next, and is then recirculat¬ ed. Transfer gate 21 is disposed between photovoltaic- ferroelectric cells 20 and the charge control device register.In operation,- when calls 20 are illuminated, they output a signal indicative of the stored remanent polarization to the corresponding cells of the register through transfer gate 21. After this is done, the in- formation is read out along the register at the desired rate.The ferroelectric ceramic elements can be formed directly on a silicon substrate on which the CCD regis¬ ters are formed using large scale integrated circuit technology. Information can be introduced into the in¬ dividual memory cells by a replication technique from a master or directly using a moving electric contact, a charging electron beam, or other appropriate method. The above-described device may be viewed either as a self-scanning data record or as a charge control memory with photovoltaic ferroelectric cells being uti¬ lized to make the stored information permament instead of temporary. As is known to those skilled in the art, one of the problems with conventional charge control memories is that the information needs to be refreshed periodically. In Figure 7, another embodiment of a self-scan¬ ning device is shown, which embodiment utilizes a con¬ ventional shift register in conjunction with individual transfer switches. Referring to the Figure, individual ferroelectric ceramic elements 24 are connected through individual transfer switches 25, which may, for instance, be solid state switches, to the cells of shift register 26. In this embodiment, if desired, the shift register can be utilized to sequentially apply a fixed or varying voltage to the individual ferroelectric ceramic elements sufficient to produce remanent polarization representing information. Readout is accomplished by the reverse operation, the charge produced by the elements upon illum¬ ination being transferred to the shaft register, and being shifted out to processing circuitry in conventional fashion. To represent the alternative write and read functions, pole or read switch 27 is shown. As well as being a self-scanning record, the device shown in Figure 7 is also a sequential non-volatile read-write memory. An extension of the embodiment of Figure 7 is shown in Figure 8. In this embodiment, multiple rows of ferroelectric' ceramic elements are utilized in conjunct¬ ion with a single transfer switch, and the individual rows are scanned by being selectively illuminated. This embodiment can be utilized as a read-only memory or as a data record. Polarization information can be entered in a variety of ways, for instance, by voltages applied through sets of electricl contacts.Similarly, the embodiment of Figure 6 can be extended to the multiple row concept by providing multi¬ ple rows of cells and by connecting the row cells of each column in parallel with each other. Again, either a read-only memory or a self-scanning record is provided. It should be understood that while the storage and readout apparatus of the invention has been described, heretofore in conjunction with a disk, it also applies to tape and drum media.I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications can be made by a person skilled in the art.-BUR O | What is claimed is:1. A photovoltaic information storage and read¬ out apparatus comprising, a substrate of a ferroelectric ceramic material, means for applying an electrical signal across at least a region of said substrate to effect a remanent ferroelectric polarization in said region representative of said information to be stored, means for illuminating said at least a region of said substrate with a source of radiation, whereby a photovoltaic voltage is produced at said region having a polarity dependent on the polarity of said electrical signal, and means for detecting said photovoltaic. oltage, whereby the stored information is retrieved.2. The apparatus of claim 1 for storing digital s~ignals wherein said means for detecting comprises means which is responsive to the presence or absence of said photovoltaic voltage.3. The apparatus of claim 1 for storing analog signals wherein said means for detecting comprises means responsive to the amplitude of said photovoltaic voltage.4. The apparatus of claim 1 wherein said substrate is disk-shaped, is deposited on a conducting surface, said means for applying an electrical signal .comprises means for applying a signal to said substrate in a spiral tracking pattern,5. The apparatus of claim 4 wherein said disk has an exposed surface and said means for illuminating com¬ prises means for illuminating the entire exposed surface simultaneously.6. The apparatus of claim 5 wherein said means for applying an electrical signal comprises means for applying a plurality of electrical signals in concentric spiral tracks. 7. The apparatus of claim 6 wherein said means for detecting comprises means for detecting a plural¬ ity of photovoltaic voltages in concentric spiral tracks.8. A self-scanning information storage and read-out apparatus comprising: a plurality of cells of ferroelectric ceramic material, each cell being remanently polarized, means for illuminating said cells, and means for detecting the photovoltaic voltages produced by each of said cells.9. The apparatus of claim 8 wherein said means for detecting includes transfer means and register means.10. The apparatus of claim 9 wherein said re¬ gister means comprises charge control device register means.11. The apparatus of claim 9 wherein said re¬ gister means comprises shift register means.12. The apparatus of claim 9 wherein said plurality of cells comprises a plurality of rows and columns of cells, and said means for illuminating com¬ prises means for illuminating a selected row at a time.13. A method of storing information comprising, providing a substrate of ferroelectric ceramic material, applying an electrical signal across at -least a region of said substrate to effect a remanent ferro¬ electric polarization in said region representative of said information to be stored, illuminating said at least a region of said sub¬ strate with a source of radiation whereby a photovoltaic voltage is produced at said region having a polarity de¬ pendent on the polarity of said electrical signal,and detecting said 'photovoltaic voltage, whereby said stored information is retrieved. 14. A self-scanning information storage and readout apparatus comprising, register means, a plurality of cells of ferroelectric ceramic material, and transfer switch means between said register means and said cells for poling said cells.15. The apparatus of claim 1 wherein said sub¬ strate comprises at least a part of a tape.16. The apparatus of claim 1 wherein said sub¬ strate is depicted on a drum.-BUREAU OMPI | PHOTOVOLTAIC CERAMIC CORP; PHOTOVOLTAIC CERAMICS CORP | BRODY P |
WO-1979000108-A1 | 1,979,000,108 | WO | A1 | EN | 19,790,308 | 1,979 | 20,090,507 | new | F16L1 | E02B3 | E02B3, F16L1 | E02B 3/12C, F16L 1/12A | A SYSTEM FOR DEPOSITING SEDIMENT AND/OR PROTECTING AN INSTALLATION ON THE FLOOR OF A BODY OF WATER | This invention relates to a device which deposits sediment and/or protects an installation on the floor of a body of water. A ridge-like heavy, sectioned structure in its cross-section is divided in pairs of supporting symmetrical parts (1) and, resting on these parts, symmetrical movable parts (3) which are prevented from sliding downwards, but may be removed upwards along the supporting parts (1). Upon such removal the supporting parts make up a secondary shield, until the movable parts (3) have been re-positioned. | A SYSTEM FOR t-EPOSITING SEDIME- T AND/OR PRJTEX-TING AN INSTALLATION ON THE FLOOR OF A BODY OF WATERThe invention relates to a system for depositing sediment and/or protect¬ ing pipelines, cables and the like en the floor of a body- of water. A ridge-formed system <_*cr_sisting of a plurality of mutually displaceable exanpenents for depositing sediment and/or protecting an installation against fishing gear, ships' anchors, and the like, is already known.The present invention as defined in Claim 1 presents a system which is so flexible that it can adapt to very rugged seabed contours and at the same time maintain a continuous surface to further the sediment deposit¬ ing effect and to present no obstacle to fishing gear passing over the system.The upper surface of the flexible system according to Claim 2 has no dis¬ continuations, even with different settlements of adjacent modules. The fastening according to Claim 3 presents a simple and cheap method of connecting the movable parts to the supporting parts.The hooked connection according to Claim 4 allows for release of the ties in case of removal of the movable parts over top of the structure. A perforation according to Claim 5 reduces the lifting forces on the structure.Flaps according to Claim 6 ensure a steady contact between structure and seabed, so that fishing gear always slides over the structure without hooking its edges. The system acxrar ing to Claim 7 is able to absorp very great iitpacts frcm dropped objects.The unprolongable ties according to Claim 8 prevent the top of the protec¬ tive cover frcm cc-fiing to rest on the installation to be protected. The cx_r_struction material according to Claim 9 ensures flexibility and tight contact with the seabed. The method according to Claim 11 allcws for ir iediate start of production anywhere, either near the site of installation or in the nearest harioour, and possibly for saving of transport of sand and stones frcm shore. The method according to Claim 12 gives a very high production rate per da The method according to Claim 13 presents a maxiιτ_ιm laying speed. By the method according to Claim 14 the laying of the protective cover to a certain extent is independent of weather conditions.The method according to Claim 15 presents a rational, cheap laying of the covers when they can be laid together with the cable or the pipeline. The materials according to Claim 16 allow for adjusting the duration of dissoluticn of the materials to duration of the laying procedure.In the following description reference will be made to the drawing in which: Fig.1 is a cross-section taken along the line I-I of Fig.2,Fig. 2 is a plan view of a preferred embodiment of the invention. Fig. 3 is a longitudinal section taken along the line II-II of Fig. 1, Fig.4 is a cross-section taken along the line IV-IV in Fig.5 of an alternative embodiment of the invention, Fig.5 is a longitudinal section along the line III-III of Fig. 4,Fig. 6 is a cross-section of a catamaran type laybarge provided with jac up legs. Two different water level situations are shewn in the figure.In p___ticular on uneven and/or hard clayey or rocky seabed, flexibility of the protective structure is iπportant. This may be obtained for in- stance by means of a short length of the modules in which the cover is sectioned, and by flexibility between the individual cαπponents of the structure/ cf. Figs.1-5.By means of flexible borders consisting of narrow, pivotally hinged mem- bers4, a tight contact with the seabed is obtained, even if this is un- even or beccrnes eroded. Trawl- and other fishing gear therefore always slides over the s-tructure without catching hold of its edge. The members 4 are kept together by wire means 6 passing through holes in the members 4, so that the vertical jumps between adjacent m__mbers are liπated, and they form a continuous surface. The slidable primary shield 3 appropriately may be triangular and suppor ed on the gently sloping edges of the triangular upper surfaces 2,of the supporting parts 1 which form the secondary shield of the structure. Eve if -..evenness of the seabed or erosion cause a mutual vertical displace- men , p r sides and always remain in tight contact all the way along these.As shown in Fig.5, 1 may be further divided in a supporting lower portion 1 and 2, and a loose upper portion 7 resting on either 2 or 3. 3 may be prevented frcm sliding downwards for instance by means of at least one tie connecting a point of the underside of 3 with the top of 1, for instance with the axle 5 of the hinge between the syirπetrical halves of 1. The tie will allow for 3 to move upwards over top of 1 in case a dragging anchor hooks the edge of 3. The connection between the tie and 3 and/or the top of 1 may be some type of hook that releases its grasp when the tie is tightened after 3 has passed over the top of 1.For neutralization of hydraulic pressure differences between over- and underside, and to further sedimentation under the structure, appropriate portions of this, for instance the transverse joints between adjacent modules 1, and/or between 2 and 3, may be perforated.To prevent the top of the protective cover from sinking so far that its underside cones to rest on the installation to be protected, the top hinge between the sy netrical halves of 1 may be designed so that the acute ■ angle between the halves can open up only to a certain point. A simple way of cbtaining this is to place the axle 5 below the centre of the half- circular mating parts of the hinge, cf. Figs. 1 and 4.Normally the construction material is concrete- Also other materials are applicable. To obtain plasticity, 4 and possibly 3 and 2 may be formed of longitudinally extending cushions made of for example plastic cloth filled with sand or stones, possibly mixed with asphalt with permanent plasticity, so that it will always follow after, if the seabed along the edges of the structure is eroded. To optimize the shape of the cushions to resemble the stable configuration shown in Figs. 1-5, the underside of the cushions may be provided with horizontal stays. The invention may be used for protection of for example subrr_ιrine pipe¬ lines near offshore platforms from objects falling overboard from the platforms. To increase the capacity of the cover to absorb the impact of a dropped object hitting the cover, opposite syi etrical halves 1 of the structure may be interconnected by prolongable tie means 16 above (Fig.l) or below the installation 15.to be protected. The kinetic energy of the falling object thereby is reduced with the energy required to prolong the tie 16 when the falling object depresses the top of the cover and conse-ITUREA / OMPI Λ* W1PO . fc-y quent y sprea s t e s es o e cover. T e t e may e ma e o e astic ιr__- terial, e.g. neoprene or natural rubber, or of plastic, e.g. nylon, alumi¬ nium, steel or other material. Lowering of the top of 1 to the level of the top of 15 may be prevented by an excessive strength of 16 or by means of additional ties with higher strength than that of 16.Depending en the distance from shore, the covers may be fabricated on shore and transported to the installation site on a surface vessel. Or the fabrication may take place onboard a mothership. If the construction mate¬ rial for instance is concrete or sediment filled cushiens, the sand and stones involved may possibly be taken frcm the sea bottom in the near of the site of installation.Concrete modxiles preferably are fabricated by a irachine that puts the con¬ crete under pressure and vibration at the same time, whereby the produc¬ tion rate per day can be increased very considerably. Small unccπplicated elements to protect for instance a cable or pipeline of minor diameter may be laid at the same time as the cable or pipeline is laid. If cables are laid pairwise, the elements may have two parallel lαgitudinally extending notches for the cables on their undersides and be placed on top of the cables during the laying operation. The elements may be attached to the cables by means of ties that becαre dissolved by the water shortly after the laying, so that the elements get freed from the cables. The ties may for example be made of polyvimylalcohol coated with a layer of cellulose the thickness of which is adjusted to the time it takes to lay the cables. The elements may also be placed on a single cable to be laid, if cable and elements are hanging from an auxiliary wire that is wound off from the laybarge in the same way as the cable is laid. The attachment of the cable and elements to the auxiliary wire may be performed by the same kind of dissolvable tie as described above. Larger covers may be laid in deeper water by means of an unmanned, remote¬ ly controlled submersible. Normally a mothership at the site of installa¬ tion is required for attaching the covers to the submersible. The mother- ship is supplied with a crane capable of lifting the submersible up to the deck through a moonpool, or outboard the stern, and afterwards lσwer- ing the sx±mersible with the attached covers into the water. Alternatively the mothership may have an opening under water through which the submer¬ sible can pass. The mounting of the covers to the submersible in this case may be performed by divers under water, or take place in a hold of the ship that can be made dry during the mounting of the covers.In shallower water where the influence of the waves is even more critical for the laying operation, the covers may be laid for instance by means of a special catamaran type barge as shewn in Fig.6. The syirmetrical hal- ves 8 of the barge are interconnected by portal frames 11 on which cranes 10 can move transversely and longitudinally, and by means of a frame 14 lift a row of modules 12 from the supply barge 13 and lower them to rest over the pipeline 15 on the bottom, when the supply barge 13 has been re¬ moved. The laybarge is supplied with jack-up legs 9. During the laying of each row of modules, the barge is raised above the water surface to mini¬ mize the influence of the waves. When the length of protection correspond¬ ing to the length of the laybarge has been laid, the legs 9 are jacked up, the barge is moved one length forward, is raised above water surface, etc. | :1. A .system for depositing sediment and/or protecting an installation on the floor of a body of water, ccxrπprising an elongate structure of rigid and/or flexible material, said structure including a longitudinally exten- ding centre portion which, in use, is placed over the floor, and two longitudinally extending side portions the upper surfaces of which, in use, diverge away frcm each other to said floor, said structure being so heavy that no anchoring of the structure is necessary, and wherein said structure is sectioned in modules each of which in its cross-section is divided in a pair of symmetrical supporting parts resting on the floor, and - resting on these supporting parts - at least one pair of syi etrical ovable parts which are prevented from sliding downwards, but may be moved upwards along the surface of the supporting parts.2. A system according to Claim 1, Vvherein the upper face of the struc- ture is divided in triangular plates that mutually support eachother.3. A system according to Claim 1 or 2, wherein said movable parts are prevented frcm sliding downwards by means of tie means fastened to points of the undersides of the movable parts and by the other ends to the ridge of the s-fcructure. 4. A system according to Claim 3, v_herεin said tie means are fastened by means of hooks that release their grasps in case the corresponding movabl parts are moved over the ridge of the stn_cture.5. A system according to any preceding claim, wherein the lower edge of said movable parts on either side of the str_cture is provided with a flexible border of transversely extending narrow marbers that are pivotal ly hinged to said movable parts and mutually connected by longitud1na1ly extending ties.6. A system according to any preceding claim, wherein opposite halves of the supporting parts are intercαι__ected by prolongable ties. 7. A system according to Claim 6, wherein prolongation of said prolong¬ able ties is limited by unprolongable ties that are longer than the ori¬ ginal length of the prolongable ties.8. A system according to any preceding claim, wherein at least part of the structure is fabricated frcm plastic material. 9. A system according to Claim 8, wherein said plastic consist of cu¬ shions of cloth filled with sedimentary material.10. A method of fabricating the system according to Claim 1, wherein fabrication takes place onboard a mothership, and wherein the materials for fabrication possibly are taken from the seabed. 11. A method of fabricating the system according to Claim 1, wherein the protective structure is made of concrete and fabricated under simultaneous pressure and vibration.12. A method of laying the system according to Claim 1, wherein a row of modules at a time are laid by means of an unmanned, remotely controlled submersible that in order to be loaded with another row of modules each time either is lifted up to the deck of the _τothership or through an open¬ ing in the mothership sails into a hold of this.13. A method of laying the system according to Claim 1, wherein a row of modules at a time are laid by means of a catamaran type laybarge provided with jack-up legs and with cranes that can move in the longitudi al and transverse directions, and wherein said laybarge is jacked up above the water surface en said legs during the laying operation.14. A method of laying the systan according to Claim 1, -wherein the indi¬ vidual modules during the laying operation by ineans of water-dissolvable ties are fastened on top of the cables or pipelines to be laid, and/or are hanging from an auxiliary wire.15. A method according to Claim 14, wherein the water-dissolvable ties consist of polyvinylalcohol coated with a layer of cellulose of suitable thickness.16. A system for depositing sediment and/or protecting an installation on the floor of a body of water substantially as herein described with re¬ ference to any of the drawings.17. Ifethods of fabricationg and using a system for depositing sediment and/or protecting an installation on the floor of a body of water substan¬ tially as herein described with reference to any of the drawings. | HARTLEY D; LARSEN O | LARSEN O |
WO-1979000109-A1 | 1,979,000,109 | WO | A1 | XX | 19,790,308 | 1,979 | 20,090,507 | new | F16L1 | E02B3 | E02B3, F16L1 | E02B 3/04B, E02B 3/12C, F16L 1/12A | A SYSTEM FOR PROTECTION OF AN INSTALLATION ON THE FLOOR OF A BODY OF WATER | A system for protection of an installation (1) on the floor of a body of water from damage due to erosion, dragging ships' anchors and fishing gear. A flexible mat (16) covering the installation (1) prevents underscouring of the installation. The edges of the mat resting on the floor are so thick and rigid that a dragging anchor (10) or fishing gear hooking the edge will be carried over the installation (1) by the roll (9) of mat formed by the anchor or fishing gear. Elasticity of the mat and/or its edge causes the mat to roll back to resume its original configuration after the passage of the anchor or fishing gear. | A SYSTEM FOR PROTECTION OF AN INS ALLfiJION CN THE FLOOR OF A BODY OF WATERThe invention relates to a system for protection from damage due to scour, ships' anchors, fishing gear, etc., of a pipeline, cable, foundation or other installation on the floor of a body of water. Various devices for protection against the eroding effect of waves and currents,only, exist. An alternative system protecting against erosion, anchors and fishing gear depends on hooking anchors being carried over the installation by movable plate-like members which slide and/or turn over top of the installation. Such plate-like members have to be strong enough to carry the weight of the hooking anchor.The principle of functioning of the present system as defined in Claim 1 implies that the hooking anchor winds or folds the protective mat together and is carried over the installation by the rolled or folded mat. The re¬ quired strength of the individual msirber of the system and thereby the cost of fabrication is minimized. Furtherπore, the present system is easier to install.For simplification the following description will refer to protection of a submarine pipeline as a typical example. It is obvious that the system, or at least its side portions, can be used for protection of any submarine installation. In the description reference will be made to the drawing, in whichFig. 1 is a cross-section of a pipeline 1 protected by a mat the side por¬ tions of which slope all the way frαn center portion to edges, Fig. 2 is a cross-section of a pipeline where the innermost portion of ' each side portion of the protective mat slopes, whereas the outermost por¬ tion rests on and follows the contour of the floor,Fig. 3 is a cross-section of a pipeline where the center portion of the protective mat embraces the pipeline, whereas the side portions rest on the floor,REA ΓO Pl .A,. WiPO - Fig. 4 is a cross-section of a pipeline protected by a net consisting of two layers of sheet material forming a bag filled with sediment or other fill material,Fig. 5 shews the same as Fig. 4, but the bag is here supplemented with horizontal portions of mat of blocks,Fig. 6 is a longitudinal side view of a tube forming the edge of the mat, Fig. 7 is a cross-section taken along the line I-I in Fig. 6, Figs. 8-10 are alternative cross-sections perpendicular to the pipeline of a mat of sheet material, with longitudinally extending notches in its upper surface, channels in its upper half, and slits in its underside, respectively,Figs. 11-16 are cross-sections perpendicular to the pipeline of alterna¬ tive shapes and interconnections of blocks forming the protective mat. Figs. 17 and 18 are alternative longitudinal sections along the line II- II in Fig. 16 and show wo alternative couplings in the joints between blocks forming a mat,Fig. 19 is a plan view of a mat consisting of ball-shaped blocks, Fig. 20 is a plan view of a mat consisting of double-cone-shaped blocks, Fig. 21 is a cross-section along the line III-III of Fig. 19 or IV-IV of Fig. 20,Fig. 22 is a cross-section perpendicular to the pipeline of a preferred eirbodirnent of the invention,Fig. 23 is a cross-section perpendicular to the pipeline of a mat con¬ sisting of scrapped tyres, Fig. 24 is a cross-section of a mat wound into parallel rolls resting on the pipeline,Fig. 25 is a side view of an arrangement for laying the mat, Fig. 26 is a cross-section along the line V-V in Fig. 25.Depending on weight distribution in the mat, and -sediment transport con- ditiαns at the installation site, the protective mat in principle may assume the three different configurations shown in Figs. 1-3. The configurations shown in Figs. 1-2 are favourable in areas with sedi¬ ment transport. If the sloping portions of the mat 16 are impermeable enough to conduct the current over top of the pipeline 1, a deposition of sediment 8 will take place underneath and on top of the mat, Figs.1,2,3. The roll of mat 9 formed by a hooking anchor 10, Fig. 22, there¬ fore will roll upwards on top of the deposition. Furthermore,-the sedi¬ ment on top of the mat will increase the diameter of the roll 9. For both reasons a smaller width of the mat is needed to obtain a certain roll diameter in sea bottom areas with sediment transport than in areas without such transport.If the mat is not anchored in the bottαn, the configuration shewn in Fig. 1 __equires that the edge portions of the mat are much heavier than the sloping portions.In areas without sedirrent transport, designs of the mat as shown in Figs. 4 and 5 are appropriate. The weight of the fill material 39 in the bag 38 may also be desirable, if the protective system also is to substitute the weight coating of a pipeline.The design of the mat may be based on 4different provisions: a) In particular in areas without sediment transport,the width and thick¬ ness of the mat are so large that the diameter of the rolled or folded mat formed by the largest anchor hooking the edge, before passage of the pipeline,has gained enough to make the anchor slip over the roll of mat, and the. elasticity and/or the weight of the mat will make this roll back , to its original position. b) In particular in areas with sediment transport, the width and thick¬ ness of the mat are large enough to make the anchor slip over the roll of mat before it arrives at the opposite edge of the mat. c) In particular in areas with sediment transport, the strength of the mat in its longitudinal direction may be so low that the roll of mat breaks when the anchor has passed over the pipeline, so that the anchor can move on, without passing over the roll of mat. d) In particular in areas with sediment transport, the mat may be sec¬ tioned into shorter, overlapping lengths along the pipeline. After having passed over the pipeline, the anchor will take a section of mat away.A hooking anchor's initiation of a -.oiling displacement of the edge of mat depends on a certain rigidity of the edge. Ωie horizontal drag of a hooking anchor or fishing gear should be spread over a certain length of mat. Otherwise the anchor will wedge into the edge of the mat. Furthermore, the geometrical and frictional resistance should be so little, that a positive rotational nent as to the lower side of the edge results. To prevent the edge frcsn getting caught in the corner between shaft and flukes of the anchor, the edge should also have a certain minimum thick¬ ness.These requirements may be fulfilled by bending the edge around, either up¬ wards, Fig.2, or dewnwards, Fig.3, or all the way round to form a closed.-OMPI WP 0 tube, Fig.l. Alternatively, a separate tube 4 may be attached to the edg Figs. 5-7 and 22. The tube may be filled with for instance sediment, or balls of concrete, or cne or more longitudinally extending stays. The tube must have a certain flexibility and elcngability to fulfill its purpose. o carry the weight of at least the dragging anchor chain,it mas at the same time have a certain radial strength.One solution to these requirements is a tube made of neoprene reinforced with at least one spiral-shaped wire fabricated forinstance of steel, Figs. 6-7. To provide bearing capacity, one of the spirals, 40, may have a lew pitch. To provide rigidness, another spiral, 41, may have a higher pitch. Both spirals allcw for prolongation of the tube in case an anchor hooks it.Longitudinal meπbers, e.g. the spiral 41,may project above the surface o the tube, to provide a foothold for the anchor chain, so that it can ro- tate the tube.If the tube 4 consists of rigid material, e.g. concrete, steel, aluπ niu and/or plastic, the tube may be sectioned to obtain flexibility and elcn ability. The joints between adjacent sections may be telescopic to provi continuity. The tube may be perforated so as to πύi-imize the hydraulic resistance an to become filled by the natural sediment transport. It may even consist oppositely spiraled wires forming mesh of for instance steel coated with plastic, neoprene or the like.To spread the horizontal drag force over a length of the mat, the mat ma contain one or more longitudinally extending parallel stays, solid or hollow, at least along the edges of the mat. Although rigidness of the edge portion is required to prevent a hooking anchor from wedging into t edge, the for ation of a roll of mat implies a certain longitudinal pro¬ longability of the mat, at least of its edge portions. From the edge to- wards the pipeline the prolongability may gradually decrease. If the mat contains stays made of unelastic material, they may be sectioned and sta gered in channels in the mat, so that elongation of the sheet is not pre vented by the stays. The length of the sectioning may gradually decrease toward the edges of the mat. To increase the ability of the mat torollback to its original position, after a hooking anchor has passed over it, the mat in its longitudinal and/or transverse directions may be made of elastic material. A decrease of the elasticity tcward the pipeline may be obtained by vary. ing the elasticity and or kind of material and or thickness of the mat, either continuously from edge to centerline or by way of abrupt changes of these properties.To πtinimize the lifting forces of the current, the mat may contain perfo- rations and/or openings of various shapes and sizes to neutralize the ■ difference of hydraulic pressures between the two sides of the mat. The holes should be located and/or shaped so that anchors and fishing gear will not catch hold of them. In areas with sediment transport the sloping portions of the mat -should be tight enough to conduct the current over top of the pipeline.The mat may be made of many different kinds of material. In the following, 4 different groups of structures will be mentioned:1) Mats consisting of at least one layer of -sheet material2) Macs of blocks bonded together by sheet, net and/or ties 3) Cαrbinations of 1) and 2)4) Mats of scrapped tyres. re 1) : The sheet may be elastic, and made offor example neoprene or na¬ tural rubber, and/or plastic, e.g. polypropylene, polyethylene, nylon, . . • etc., or made of natural fibres, i.e. sisal, hemp, etc. To increase the weightof the mat, it may be built up as a sandwich struc¬ ture including for instance water-absorbent rubber- or plastic-'foam, or composed ofamixture of suitable fill material, e.g. sand, and rubber, plastic, bitumen or the like. To increase the strength, the sheet may be reinforced with for instance steel, nylon or other plastic, in at least one direction.A sheet that has too little weight to be stable has to be.anchored in the seabed, orfastened to the pipeline, either by means of the pinching ef¬ fect of the eπbracing portion of the sheet itself, cf. Fig.3, or by means of clamps. Or the mat may be weighted by naturally (Figs. 1-3) or artifi- . cially supplied sediment.In the latter case the sediment may be enclosed in the space between two layers of sheet formingaclosed bag 38, Figs.4 and 5, which may be divided into compartments by transversely and/or longitudinally extending -secon¬ dary walls. Alternatively, the bag may be filled with for instance balls or longitudinally extending rolls or pipes of concrete or plastic, of foaπ -rubber or -plastic, or other fill material. Transversely and/or lon¬ gitudinally extending,horizontal and/or oblique stays, e.g. positioned as 42 or 43 in Fig.4, may further the function of the mat.-BUREAU0MPI _.A WIPO If the bag 38 consists of for instance nylon-reinforced neoprene, the flukes of an anchor having reached somewhere underneath the bag 38, will easily slip over the bag because of the loose fill material and the smooth underside of the bag. • To further the tendency of a -sheet to fold asa roll in case of an anchor• hooking its edge, the sheet appropriately is structured as shewn in Figs. 8, 9 and/or 10. The longitudinally extending notches 44, slits 45 and/or channels 46 all ease the upward concaving of the sheet.In stead of arranging 44, 45 or 46 in the sheet itself, they may be placed in possible transversely extending thickened parts of the sheet, or in separate beams of a different material.A sheet divided in longitudinally extending bands/of relatively rigid material connected by flexible material will tend to fold like an accor¬ dion. The tendency may be enhanced by placing the ccnnections alternately at the upper and lower surfaces of the rigid bands, Fig. 14. re 2) : The preferred material for fabrication of blocks is concrete. But also other materials may be used. To facilitate laying ofamat of blocks, the weight may be reduced by use of light weight concrete, or even a spe¬ cial water-permeable concrete containing cavities or pores that will fill with water after the laying. To delay such absorption of water, the blocks may be coated with sαre soluble material, e.g. cellulose. The individual block may be shaped for instance as a cube, a box 22, Fig. 12, a parallelepiped 19, Figs.13, 14, a trapezoid 20, Fig.11, a ball 18, Figs.19, 21, a roll 2, Figs.16-18, 22, a double cσne 21, Figs.20, 21, an ellipsoid,or other shape.Elongate blocks are placed parallel with the edge of the mat, and prefer¬ ably with staggered ends.The blocks being placed close together, the upper edges parallel with the pipeline of box-shaped blocks 22 may be cut off as shown in Fig.12. The ' edge portion of the mat forming the center of the roll formed by a hooking• anchor, the angle ©C, Figs. 11 and 12, between neighbouring blocks may gradually decrease frcm a maximum at the edge to a ιr_i-n-L_πum at the center- line of the mat. If the strength of the mat allcws therefore, oC may be so small that the roll of mat becomes tube-formed, with a larger diameter than that of the corresponding solid roll.If the upper surface of a block is not covered by a sheet, the upper part of the block preferably should be rounded, Figs.16-22, to prevent the an¬ chor flukes from catching hold. To make up a quite even outer surface of the roll of mat, the underside 23, Fig.11, of the blocks may be rounded. The radius of the circular un¬ derside should gradually decrease toward the edges of the mat.The blocks may be interconnected by one or two sheets 25, by a net 29, and/or by ties 5 and 6, fastened to the blocks at their upper or lower surfaces and/or at a level somewhere between these surfaces. To prevent upward c-onvexity of the mat, in particular along its edges, the connect¬ ing ire bers between the blocks 22, Fig.12, or 24, Fig.22, depending on their shape may be placed above their underside (Fig.12) or above their centerline (Fig.22) .The connecting material in one and/or the other direction of the mat may be elastic and consist of for instance eoprene or natural rubber and/or be plastic and consist of for instance polypropylene, polyethylene, nylon or natural fibre material. Fig.15 shows a mat consisting of ball- or roll-shaped blocks enclosed be¬ tween two layers of sheet 25 of for instance neoprene or plastic, which may be interconnected by longitudinal walls 26. The upper layer.of sheet may be reinforced or fortified in direction perpendicular to the pipeline. The lcwer layer may be un-reinforced and made of for instance neoprene that can elongate in both directions. Besides the balls or cylinders, the space between the two layers may be filled with smaller balls or cylin¬ ders or some kind of fill material, e.g. sand. Appropriately the diame¬ ters of the balls or cylinders gradually decrease toward the edges of the mat, to ease the formation of a roll of mat, if an anchor hooks the edge. Ball- (Fig.19) , double cone- (Fig.20), or ellipsoid-∑shaped blocks for maximum diameter of a roll of a hooked portion of mat, at a minimum vo¬ lume of biock material, may be interconnected by means ©f a flexible ca¬ sing 27 or 28 enclosing the blocks. The diagonally (Figs.19 and 20) or rectangular shaped casing may be made of flexible materials such as pla- stic, neoprene, etc., and/or flexibly connected rigid materials such as plastic, neoprene, concrete, alum__nium, etc. In one or the other direction the casing may be elastic so as to allow for insertion of the blocks 18 or 21 into the compartments of the casing, and for elongation of the mat in case an anchor hocks its edge. Without other means than the casing 27 or 28 to hold the blocks, these may be pressed out of their compartments and act as rollers in case an anchor hooks the mat. In addition to the casing, the blocks may be interconnected by transverse and/or longitudi¬ nal ties, which may be elastic. The ties may be attached to the surface of the blocks or pass through channels in these.-BU EATΓO PI _, A> W1PO , - , Figs.16-18 and 22, even on a rugged seafloor, the joints between adjacen blocks may be spherical, so that one end of the individual block is formed as a concave half sphere; the other end as a convex half sphere fitting into the concave end of the adjacent block.Appropriately the joints are provided with couplings. These may be doubl ccnvex (Fig.17) , plane (Fig.18) or double-concave. Each transversely ex¬ tending line of disk-sshaped couplings (Fig.18) may be formed as one con¬ tinuous plate made of flexible material, e.g. neoprene or polypropylene. The outer periphery of each disk follcws the contour of the roll 2, and the disk includes a channel 7 for he tie 5. Alternatively, at least pa of each transverse line of couplings, in particular at either edge of the mat, may be divided in shorter sections overlapping eachother. If ea section couples only two adjacent blocks, it may be made of rigid materi e.g. plastic or metal.To protect the ropes 5 from damage and/or to prevent too large mutual ve tical displacement between adjacent blocks, each joint may contain a lon gitudinally extending tube 31, Fig.18, of resistable material enclosing the rope 5. The tube may be continuous over the total length of the rope or be sectioned on either side of each joint, or may form part of the block 2. At least the peripheral part of the tie 5 may be reinforced wit resistable material.Ball-sshaped couplings 3 provide continuity of the surface of a mat of ro shaped blocks, even if the seabed is uneven. Fig.18. The couplings 3 are in transverse direction connected by continuous tie means 6 cast into or passing through channels in the couplings. In the longitudinal direction they are connected by the tie means 5 passing through channels 7 in the blocks and couplings. Suitable materials for fabrication of the ties 5 and 6 are for instance neoprene, natural rubber, polypropylene, aromatic polyamide coated with a harder wearing material, and/or nylon or other materials. The elasticity of 5 and or 6 may increase more or less gradu¬ ally toward the edges of the mat.The distance between neighl-ouring couplings and thereby the rolls 2, and or the diameter of the rolls, may vary over the width of the mat. To eas the formation of a roll of a hooked portion of mat, this distance may gradually increase, and the diameter of 2 and 3 decrease, toward the edg of the mat. In order to tighten the mat, so that it can conduct the wate current over top of the pipeline, Fig.22, the said distance appropriatel is nil in the two sloping portions of the mat. These two portions may al betightened by puttying the spaces between a jacent rolls 2 with an appropriate kind of plastic substance. Alternatively, a tight flex¬ ible sheet ira e of for instance neoprene may be attached to one or the other side of the mat of concrete blocks, which in these sloping porticns of the mat may be cylindric or have other shape. If blocks within the two portions are not needed to obtain a sufficiently large diameter of roll of a hooked portion of mat, the said two portions may also consist of watertight -sheet made of for instance neoprene, only. re 3) : Fig. 5 shows one example of a cαrbir-atiσn of 1) -and 2) : Ihe center portion 38 of the mat may consist of two layers of sheet materi¬ al forming a bag filled with for exaπple sedimentary material. The hori¬ zontal edge portions may consist of mats of blocks.In another exairple mentioned above the sloping portions of the mat con¬ sist of a single layer of impermeable sheet material, and rest of the mat is made up of interconnected blocks. re 4) : To obtain a cheap mat and at the same time solve an environmental and waste problem, the mat may be made of scrapped tyres tied together as shown in Fig.23. Ihe orientation of the plane of the individual tyre may be vertical, cblique or horizontal to fill out the desired profile of the cover. One appropriate cαtbination is shown in Fig. 23 where the un¬ derside of the sleeping portions of the mat 33 are provided with a rcw of vertical tyres 34 on either side of the pipeline. Loose tyres may be placed underneath or on top of the mat 33.In areas with risk of dropped objects hitting the installation, e.g. a pipeline near an offshore platform, the impact of such collision may be alleviated by means of fenders, for instance the existing types of rubber fenders, or scrapped tyres, placed on top of the installation. The fen¬ ders may be placed underneath, e.g. in the form of a half tube of rubber embracing the upper part of the pipeline, and/or on top of the protec- tive mat, and/or form part of this. In Fig.22 the rolls 11 may be made of rubber and possibly have larger diameters than the rolls 2.To it -nimize the friction between a hooking anchor and the mat, and to prevent anchors and fishing gear frαn catching hold of the mat, either before or after having slipped over the roll of mat possibly formed, the lower and/or the upper surface of the mat - whether it consists of neo¬ prene, concrete or other material - and of the edge 4 may be lubricated with a water-repellent grease. To even further reduce the friction between anchor and mat, the edge 4 Figs.1-7,22, and/or the underside of the mat may be supplied with roller 37, Fig.8. On a sheet-type mat consisting of for instance necprene, the rollers may for exaπple consist of continuous, longitudinally extending rolls of neoprene or plastic, possibly reinforced, which -ire so weakly welded to the sheet, that they will be rubbed off the sheet and function as rollers by a hooking anchor. On a block-type mat the rollers may con¬ sist of concrete rolls that are weakly tied to the mat. In a roll-type of mat as shown in Fig.22 the ties 5 and/or 6 may be so elastic that they allow for the individual roll to leave its normal po¬ sition between two couplings and function as roller between anchor and roll of mat.Before the laying of a mat, it may be wound up from either edge to form two parallel longitudinal rolls. Fig.24. Compared with laying of an un- rolled mat, winding up before lowering it to the seabed has the advan¬ tages that the hydraulic resistance during lcwering is minimized, and that the stability of elastic edge portions of the mat during the lcweri will be improved, because the weight of edge portion in each roll will b transferred to the possibly less elastic longitudinal ties 5 at the cent portion of the mat.Frcm a lay barge the two rolls may be laid on top of the pipeline and un rolled to both sides. On the laybarge the mat may be wound automatically by means of two vertical longitud nally extending edge frames with at le half-circular cross-section eπbracing the edges of the mat. The two fra converging dcwnwards toward the seabed will make both side portions win tcward the middle of the mat, to form two parallel rolls close together. Correspondingly the i-nrolling of the rolls on the seabecl may be achieve means of a frame that in plan view is triangular. The foremost vertex o the frame trails on top of the mat on top of the pipeline seme distance hind the surface vessel to which it is connected by a line. The two othe vertexes of the triangular frame symmetrically positioned on either sid the pipeline move on the mat and like a snow plough spread the two rolls of mat away from eachother and thereby unroll them.A mat of blocks in its full width may be wound around a large d__um-form reel 15, Figs.25-26, and be lowered continuously to the seabed, hanging from the drum, which rotates floating on the surface or mounted on a su face vessel. To lay a rolled or unrolled mat symmetrically over the pipeline, a manned or unmanned selfprqpelled underwater vehicle that roll on wheels 13, Figs. 25-26, or walk on feet or runners on the seabed is appropriate. The ve¬ hicle on its both sides should be supplied with upwardly extending frames ancVor the above type of device for unrolling the mat and move along the pipeline ahead of the dσwn-cxming mat.In a preferred third alternative laying method, one or two vehicles 12, Figs.25-26, interconnected by transverse beams 14, of one of the above types of manned or unmanned selfpropelled vehicles supplied with various sensor systems to be controlled from a surface vessel 17 through an uπbi- lical cable 18, move along both sides of the pipeline, carrying a large drum-formed reel 15 as described above. A long length of mat 16 is wound around the drum and will then be laid very accurately over the pipeline 1 as the vehicle(s) move forward. The vehicles may have capacity to carry at least two drums at a time, so that the shifting of the emptied drums with loaded drums frcm the surface vessel 17 can take place continuously with¬ out too long interruptions.To compensate for the variations of the load on the drum, accordingly as the mat 16 is wound off the drum, water may be let into the air-filled drum. This balancing may be autocratic. The volume of water in the drum may for exairple be regulated by the pressure exerted by the drum on its bear- ings. The pressure in the cylinder of a hydraulic pressure cell inserted betoreen axle and bearing may be transmitted hydraulically to cαntroll the valves regulating the content of water in the drum. The valves being kept open by spring means, until the transmitted pressure due to the increasing weight of the water let into the drum closes the valves at a certain pre¬ set critical pressure, the total weight of the drum will be kept constant.A fourth alternative method of installing the mat comprises sectioning the mat into shorter sections and lowering each section in rolled or unrolled state to the seabed, where the sections should overlap eachother. During the lcwering, each section is hanging from a frame extending the length of the section.BU EAUOMPI VflP0 | C L A I M S :1. A system for protection of an installation on the floor of a body of water, ocπprising a flexible mat having a center portion which, in use, covers said installation, and-side portions each edge of which, in use,5 • rests on the floor a distance of at least one-time the height of the installation away frcm the periphery of the installation, said edge being so thick and rigid that the mat will form a roll, or fold like an accordion, in case a dragging anchor hooks the edge of the net.2. A system according to Claim 1, wherein said side portions slope ccn- 0 tinuously frcm said center portion to said edges.» *3. A system according to Claim 1, wherein adjacent to said center portio the innermost portion of each of said side portions slopes away frcm said installation to meet the floor, from where the outermost portion of said side portion rests on and follows the contour of the floor. 5 4. A system according to Claim 1, wherein adjacent to said center portio the innermost portion of each of said side portions extends generally ver tically downwards to the floor, and wherein the resting portion of said side portion follows the contour of the floor.5. A system according to.any preceding claim, wherein the thickness and 0 rigidness of said edg≥s is obtained by means of upwardly or downwardly twisted loops of the edges.6. A system according to any preceding claim, wherein the thickness and rigidity of said edges is obtained hy attaching lateral tubes to the edge said tubes being thicker than said mat. 5 7. A system according to Claim 6, wherein said tubes consist of elastic material.8. A system according to Claim 6 or 7, wherein said tubes are reinforced with one or more spirals of wire with one or more different pitches.9. A -system according to Claim 6, 7 or 8, wherein the surface of said 0 tubes is provided with longitudinally extending projections.10. A system according to any preceding Claim 6, 7, 8 or 9, wherein said are sectioned and have telescopic joints.11. A system according to any one of the C aims 6 - 10, wherein at least • . parts of said tubes are perforated. 5 12. A system according to any preceding claim, .wherein at least part of said mat is elastic.13. A system according to Claim 12, wherein the elasticity in at least one direction of the mat varies from middle to edge of the mat. JIJO 14. A system according to Claim 13, wherein the elasticity in at least one direction of the mat gradually increases tcward the edges of the mat.15. A system according to any preceding claim, wherein at least part of said πat contains perforations. 16. A systsn according to Claim 15, wherein all but the sloping parts of the πat contain perforations.17. A system according to any preceding claim, wherein at least part of said mat consists of at least one layer of elastic and/or plastic mate¬ rial. 18. A system according to Claim 17, wherein at least part of said sheet parallel with its edge is provided with notches and or slits and/or channels and or stays.19. A system acc-ording to Claim 18, wherein said stays are sectioned, and wherein the length of the individual section of stay gradually de- creases tcward the edge of the mat.20. A system according to Claim 18 or 19, wherein said stays are placed in channels without longitudinally binding association with these.21. A system according to Claim 17 or 18, wherein at least part of said sheet parallel or perpendicular to its edge is thickened in parallel strips.22. A system according to Claim 17, 18 or 19, wherein at least part of said sheet parallel with its edge ccnsists of parallel bands vAiich are mutually connected alternately at their upper and lcwer surfaces.23. A system according to any preceding claim, wherein at least part of said mat consists of at least two layers of elastic and/or plastic sheet πaterial*forming at least one closed space which is filled with sedimenta¬ ry material and or balls and/or rolls and/or stays parallel with or per¬ pendicular to said edge of said mat.25. A system acx»rding to any preceding claim, wherein at least part of said mat ccnsists of blocks interconnected by sheet and/or net and/or ties of elastic and or plastic and/or rigid material attached at their upper and/or lower surfaces and/or somewhere between these surfaces.26. A system according to Claim 25, wherein said sheet, and/or net and/ or or ties connecting said blocks in the direction perpendicular to and located in the edge portions of said mat, are attached to the upper parts of said blocks.27. A system according to Claim 26 or 27, wherein the shape of said blocks comprises at least one of the following configurations: cubes,- UREAUOMPI boxes, parallelepipeds, trapezoids, balls, rolls, double cones, ellipsoi28. A -system according to Claim 25, wherein said blocks in their mutual joints are -Interconnected by couplings.29. A system according to Claim 28, wherein the shape of said couplings comprises at least one of the following configurations: double convexes, plates, double concaves.30. A system according to Claim 27 and 29, wherein said blocks are shap as rolls parallel with the edge of said mat and joined together by doubl convex and /or double-concave couplings fitting into the concave, respec tively convex ends of the rolls.31. A system according to Claim 30, wherein the parallel rcws of said roll-shaped blocks in the sloping portions of said mat are kept tight to gether, whereas in the rest of said mat the rcws of blocks are spaced sufficiently to allow for a vertical flew af water through the mat. 32. A system according to any one of the Claims 25-31, wherein said blocks are interconnected by ties parallel and/or perpendicular to the edge of said mat, the ties fitting into channels in said blocks and/or said couplings.33. A system according to any preceding claim, wherein the sloping por- ticns of -said mat consist of at least one layer of -Impermeable sheet ma¬ terial, and the edge portions consist of interconnected blocks.34. A system according to Claim 33, wherein said sloping portions of sa mat consist of two layers of imperireable sheet material to form at least one closed space filled with sedimentary material. 35. A system according to any preceding claim, wherein at least part of said mat consists of interconnected scrapped tyres.36. A system according to Claim 35, wherein the sloping portions of sai mat are supported on rows of vertically positioned scrapped tyres attach to the underside of said mat. 37. A systsn according to Claim 35 or 36, wherein said mat is supplemen ted with loose scrapped tyres on top of and/or beneath said mat.38. A system according to any preceding claim, wherein at least part of the lcwer and/or upper surface of said mat and/or its edge is lubricated39. A system according to any preceding claim, wherein at least part of the edge and/or the underside of said mat is supplied with --oilers paral lel with the edge of the mat.40. A method of laying the system according to Claim 1, wherein said m is wound up to. form two parallel rolls which before the positioning of 15the installation to be protected, are placed cn top of this, and after the positioning are unrolled on the floor of the body of water.41. A method of laying the system according to Claim 1, wherein said mat before the laying, sectioπwise is wound around a reel which there¬ after is placed cn at least one underwater vehicle, the mat winding off the reel and settling over said installation as the vehicle moves along this.42. A method according to Claim 41, wherein said vehicle is i-nmanned, selfpropόlled and remotely controlled frcm a mother-=hip.43. A method accorcling to Cl im 41 or 42, wherein the redx-ctiαn of weight on said reel due to the winding off of said mat, automatically is balanced by gradual filling of the reel with water.44. A method acxx5--ding to Claim 43, vAierεin the valves regulating the content of water in the reel are controlled hydraulically by the pressure between the axle of the reel and its bearings, said valves being kept open by spring means until the weight of the water let into the reel creates a certain critical pressure between the axle and its bearings.45. A system for protection of an installation on the floor of a body of water substantially as herein described with reference to any of the drawings.46. M≥thods of laying and using a system for protection of an installa¬ tion on the floor of a body of water substantially as herein described with reference to any of the drawings. | HARTLEY D; LARSEN O | LARSEN O |
WO-1979000117-A1 | 1,979,000,117 | WO | A1 | EN | 19,790,308 | 1,979 | 20,090,507 | new | B23Q7 | null | B23Q1, B23Q3, B25B5 | B23Q 1/38, B23Q 3/10D, B25B 5/06B | BAYONET CLAMPING APPARATUS FOR MACHINE TOOLS | Apparatus for clamping a workpiece or workpiece fixture (32) to a machine tool, and in particular to a bayonet clamping system which is suitable for use with work tables when the fixture is floatingly supported on a film of pressurized air during movement from one machining position to another. More specifically, the table (28) has a surface (30) adapted to support a workpiece or fixture (32) which includes a plurality of openings (66) and removable covers (192) thereon. This arrangement overcomes the problem of having chips and other debris from collecting in the openings (66) and also prevents the loss of pneumatic pressure in machine tables of the air float type. A plurality of similar hydraulic pistons (96) mounted within the table (28) are adapted to be connected to locking pins (128). Clamp bars (186) are secured to the top of the pins (128) and suspended between support blocks (184) and the workpiece or fixture (32). This arrangement allows selective clamping pressure to be applied to the workpiece or fixture (32) at any point desired. | BAYONET CLAMPING APPARATUS FOR MACHINE TOOLS TECHNICAL FIELD The present invention relates to a clamping system for clamping a workpiece or workpiece fixture to the supporting table of a machine tool, and in particular to a bayonet clamping system which is suit¬ able for use with work tables when the fixture-is floatingly supported on a film of pressurized air during movement from one machining position to another. BACKGROUND OF THE INVENTION Whenever a workpiece is machined, it must be accurately positioned on the work table in proper spatial relationship to the cutting tool. Since the tool will exert considerable force on the workpiece during machining, it is also necessary that it be securely anchored or clamped in the desired position. Heretofore, work tables have been provided with T-slots normally running the entire length of the table and adapted to receive T-bolts or other fastening elements which engage clamping bars or the like for the purpose of clamping the workpiece to the table. A serious drawback to this arrangement is that considerable amounts of chips, shavings, and other debris produced during machining collect in the T-slots and frequent table clean-up by the operator is necessary.An even more serious problem exists in work tables of the type wherein the fixture is supported for movement on a film of pressurized air. A workO PI' ' table of this type is shown and described in U. S. Patent No. 4,058,885 and is designed to eliminate the time consuming, laborious positioning of the work- piece or fixture in the machine tool as various regions of the workpiece are to be machined. In this appara¬ tus, the table has passages therein which supply fluid under pressure between the downwardly facing surface of the fixture and the upwardly facing horizontal sur¬ face of the table so that the fixture floats on the film of air and can be moved above easily on the table. Cooperating elements of pin and socket locating de¬ vices on the fixture and table provide for the accurate locating of the fixture in predetermined positions on the table. It is necessary, however, to clamp the fixture to the table so. that it will not move during positioning. Heretofore, T-slots have been used for clamping the fixture but, due to the fact that they extend underneath the fixture itself, leakage of pneumatic pressure from the film of air has resulted. This increases the pneumatic pressure which is necessary to support the workpiece. Furthermore, much of the benefits of being able to rapidly reposition the workpiece are never realized due to the cumbersome clamping oper- ation which is necessary prior to machining.DISCLOSURE OF INVENTION The present invention overcomes the problems and disadvantages of the prior art by providing a plurality of openings distributed over the table surface into which clamping elements are insertable and locked therein by a relatively simple motion. By selecting the appropri¬ ate openings for insertion of the clamping elements, clamping pressure may be applied at any desired position on the table. In one embodiment, automatic clamping is effected by a hydraulic piston and cylinder mounted within the table and engageable with the locking pinIJUREAOMPI to draw it downwardly and exert clamping pressure when actuated. In another embodiment, automatic clamping is effected by a hydraulic cylinder mounted toward , the top of the clamping elements and exerts a downward pressure when actuated.Specifically, the present invention is concerned with apparatus for clamping a workpiece or workpiece fixture in a machine tool comprising: a table having a surface adapted to support a workpiece or workpiece fixture thereon, a plurality of openings in a table having removable cover means thereover, a plurality of first clamp elements being mounted within the table below and accessible through the openings, a second clamp element adapted to be removably inserted in any of the openings and including means for selectively mechanically interlocking with the first element mounted below the opening in' hich the second element is inserted, • - .. a third element on the second clamp element adapted to engage a workpiece or workpiece fixture supported on the table surface, and means for drawing the third element toward the table surface whereby a workpiece or fixture supported on the table and engaged by the third element will be clamped therebetween.It is an object of the present invention to provide a bayonet clamping system for machine tools including a plurality of female clamp elements which are distributed throughout the table and accessible through openings in the table surface so that one or more male clamp elements may be inserted through selected ones of the openings and engaged with the female element positioned thereunder by a simple twisting motion.Another object of the present invention is to provide a bayonet clamping system for machine tools wherein clamping pressure at a wide variety of positions on the table may be applied.IJUREA ΓOMPI _ A> WIPO ,Λ>, A further object of the present invention is to provide a bayonet clamping system for machine tools ' having tables of the air float type wherein the table may be formed without T-slots thereby enabling lower 5 pneumatic pressures. For example, heavy loads can be lifted .01778 cm. with as little as 1.41 kg/sq. cm. of pneumatic pressure.A further object of the present invention is to provide a bayonet clamping system for machine tools 10 enabling a relatively smooth and uninterrupted table work surface.A still further object of the present invention is to provide a bayonet clamping system for machine tools which reduces machine down time for purposes 15 of clearing chips and shavings out of the T-sϊots, as is necessary in existing work tables.Yet another object of the present invention is . ' to provide a bayonet clamping system wherein clamping pressure may be exerted automatically by means of fluid *20 actuators.BRIEF DESCRIPTION OF THE DRAWINGS The exact nature of the present invention wil2T become more apparent upon reference to the detailed description taken in conjunction with the accompanying 25 drawings in which:Figure 1 is a perspective view of a machine tool . wherein the supporting table is provided with a bayonet clamping system according to the present invention; Figure 2 is a top plan view of the table shown 30 in Figure 1;Figure 3 is a sectional view of one of the valved connections leading from a passage in the table to the surface on which the workpiece fixture is supported; Figure 4 is a sectional view of one of the locating 35 pins shown engaged with a corresponding socket in the lower surface of the workpiece fixture;IJUREOMPI ι . WIPC) Figure 5 is a sectional view of a retractable centering pin;Figure 6 is a sectional view of one of the hydraulic actuators of Figure 1 taken along line 6-6; Figure 7 is a side elevational view of one of the male clamping elements;Figure 8 is an end view of the male clamping element shown in Figure 7;Figure 9 is a top plan view of the hydraulic actuator shown in Figure 6 with the pin removed;Figure 10 is a hydraulic schematic for the clamping system of the present invention;Figure 11 is a sectional view of a modified form of the present invention; - Figure 12 is an end view of the male clamp element shown in Figure 11*Figure 13 is a sectional view of a manual clamping device according to the present invention; andFigures 14 and 15 are perspective and sectional views respectively, of a modified form of the present invention.BEST HOPE FOR CARRYING OUT THE INVENTION Referring now to the drawings. Figure 1 is a perspec¬ tive view of a machine tool having a bed 20 supported on ways 22 and 24 and a working tool 26, which may be a boring tool, milling tool or the like according to well known practice in the machine tool art. A table or plate 28 is fixedly secured to bed 20 and includes an upper surface 30 on which is supported a workpiece fixture 32 having a workpiece 34 mounted thereon.Table 28 is provided with a plurality of fluid passageways 36 (Figure 3) which are connected via a control valve (not shown) with a supply of fluid under pressure. The fluid under pressure is preferably air. but could conceivably comprise another fluid medium. Passageways 36 extend upwardly through table 28 and communicate with opening 38 in the surface 30 of table 28. As shown in Figures 1 and 2, there are many such 5 openings 38 distributed over the table surface 30 so as to provide a film of pressurized air wherever the fixture 32 is positioned. The upper end of each passage-*-. way is closed by a valve comprising a body 40 which may be threaded into passageway 36 and the top of which 0 is disposed slightly below the level of table surface 30. Valve body 40 is tubular and has captured therein a valve ball 42 which projects slightly above the surface ' * 30 of table 28 as shown in Figure 3. A spring 44 urges ball 42 into its upper closed position in which it 5 contacts circular valve seat 46.When the fixture 32 is moved on table 28 and the downwardly facing surface 48 of fixture 32 engages * ball 42, the ball 42 will be depressed as shown in Figure 3 and admit air under pressure from passageway 0 36, between seat 46 and ball 42 to the space between surfaces 48 and 30. The pressure of the fluid is so adjusted that a fluid film will be established which will floatingly support fixture 32 thereon. This enables the fixture to be easily moved about on table 28 to 5 the desired position. Obviously, when the supply of fluid is terminated, fixture 32 will come to rest directly on table surface 30. Each opening 38 includes a valve identical to that shown in Figure 3. If desired, the • • fixture -supporting pneumatic pressure could be supplied 0 from the bottom of the fixture itself rather than from' the table.It is essential that the workpiece 34 be accurately located for machining, and to this end, table 28 includes a main centering pin 50 (Figure 5) reciprocably received 5 within a bore 52 in table surface 30. Integrally formed with pin 50 is a piston 54 reciprocably received within chamber 56 and which is actuated by means of fluid pres¬ sure applied through passageways 58 and 60. Fixture 32 is provided with a downwardly opening bore (not shown) which receives centering pin 50 when the same is extended to its upper position above the surface 30 of table 28. Alternatively, a slot (not shown) in the lower surface 48 of fixture 32 may be provided so as to enable trans¬ lation of fixture 32.- When the fixture 32 is introduced into the machine, it is set down on table 28 with the pin 50 received in the corresponding bore or slot in fixture 32. When the fluid pressure film is established between the fixture 32 and table 28, fixture 32 can ro¬ tate freely about the axis of pin 50 and, in the case where a slot is provided in fixture 32, both translation and rotation are possible.In addition to pivot pin 50, there are additional locating pins 62 which' serve to accurately locate the fixture in various predetermined positions. The loca¬ ting pins 62 are located in precise positions on table 28 with reference to the tool 26. These pins 62 are engageable with sockets 64 provided in the bottom sur¬ face of fixture 32 and which are also accurately located within the fixtures 32 with reference to the location of pins 62. Thus, when one or more pins 62 engage the corresponding sockets 64 in the bottom of the fixture 32, the fixture 32 will be in an accurately located position on the table 28. When the centering pin 50 engages the fixture, only one of locating pins 62 is required to determine fixture location. Alternatively, two locating pins 62 could be employed and the fixture location determined thereby without depending on pivot pin 50.Table 28 is provided with bores 66 each of which at the upper end thereof has an elongated bushing 68. Pin 70, having a tapered upper end 72 adapted for seating in the correspondingly tapered bushing 74 in socket 64, is slidably received in bushing 68. At the lower end thereof, pin 70 is connected with a double acting piston 76 biased upwardly by spring 78 to the position shown in Figure 4. Each piston 76 has an upwardly facing fluid surface 80 adapted to be acted on by fluid from passageway 82 to drive the piston 76 and pin 70 downwardly until the upper end 72 of the pin is below the upper surface 30 of table 28. Alternatively, a supply of fluid pressure to the downwardly facing surface 84 from passageway86 will drive piston 76 upwardly to effect firm engagement of the tapered end 32 with bushing 74. The lower end of bore 88 is closed by cover plate 90. As shown in Figure 2, table 28 is provided with a number of locating pins 62 so that a number of successive machin- ing positions of workpiece 34 and fixture 32 may be realized. .By supplying air under pressure to the upper side 80 of piston 76, pin 70 will be moved downwardly out of bushing 74. If fluid under pressure is then introduced between fixture 32 and table 28, fixture -32 may be moved to the desired position. With the fixture 32 in this position, pneumatic pressure is vented from passageway 82 and pin 70 will move upwardly under the pressure of spring 78 until its tapered portion 72 engages bushing 74. Pin 70 may be driven with more force into bushing 74 by admitting pressure through conduit 86. With the fixture 32 accurately located in this manner, the supply of pneumatic pressure between fixture 32 and table 28 is then terminated and fixture 32 will come to rest on surface 30. Addition¬ al details relating to the air float table described herein may be found in U. S. Patent No. 4,058,885.One embodiment of the present invention is illus- trated in Figures 6, 7, 8, 9 and 10. It comprises a hydraulic cylinder 92 threadedly secured to anIjUREOMPI _* Λ_ WWIIPPOO elongated plate 94 which ig slidably received within elongated slots in table 28. A specially designed piston 96 is reciprocably received within cylinder 92 and has an elongated opening 98 extending therethrough. Bushing 100 is threadedly secured to piston 92 and sealed against piston 96 and cylinder 92 by means of 0-rings 102 and 104, respectively. Seal 106 seals the other end of working chamber 108 which is defined on one end by annular piston face 110 and on the other end by bushing 100. Piston 96 is urged to its upper position (Figure 6) by spring 112 and is retracted to its lower position when fluid under pressure, either hydraulic or pneumatic, is admitted to working chamber 108 through passageways 114 and 116. Port 118 is adapted to be connected to a source of fluid under pressure- through any suitable conduit (not shown) . Cylinders 92 and their respective pistons 96 •~ are located beneath openings 120 in table surface 30. Any desired number of openings 120 and piston and cylinders 96, 98 may be provided but it is preferable that there be a sufficient number to permit clamping at any desired position on the table surface 30. Cylinders 92 are accurately positioned underneath their respective openings 120 by plates 94 which slide into T-slots 95 until their ends 122, which are wider than slots 95, abut the side 124 of table 28. Any suitable means, such as tapered pins 126, may be em¬ ployed for locking plates 94 in their respective T- slots 95. The male clamping element comprises a pin 128(Figures 7 and 8) having a shank portion 130 adapted to be inserted through the opening or bore 98 of piston 96, an enlarged head 132 which is dimensioned to be received within opening 120 and abut annular shoulder 134, and a locking portion 136 having a pair of lugs or ears 138 and 140. Locking portion 136 is dimensionedA, wipo Λ> to pass through piston bore 98 when lugs 138 and 140 are aligned with the longitudinal dimension of bore 98. When pin 128 is rotated a quarter turn about . pits axis, however, lugs 138 and 140 are positioned ' to positively lock pin 128 in piston 96 (Figure 6) . As shown in Figure 9, bore 98 is somewhat elongated in the horizontal direction and the downwardly facing surfaces 142 and 144 of piston.96 will abut lugs 138 and 140 when pin 128 is rotated a quarter turn. The head 132 of pin 128 is provided with a threaded socket 150 adapted to receive a suitably threaded bolt or rod 151 for the purpose described below.Another embodiment of the present invention is shown in Figures 11 and 12 and comprises a cylinder 152 threadedly attached to elongated plate 15 4, the latter- being received within a T-slot 156 in table 28. A piston 158 is 'reciprocably received in cylinder -÷ -152 and includes a cylindrical bore 160 extending therethrough. Piston 158 is retracted by the application of fluid pressure through passageway 162 and is urged to its upward position (Figure 11) by compressed spring 164. With the exception of the configuration of. bore 160, the device shown in Figure 11 is virtually identical to that shown in Figure 6. In this embodiment, the pin 166 is threadedly secured to piston 154 by means of a pair of interrupted high pitch threads 168 which engage with corresponding female threads 170. The pitch of threads 168 and 170 is sufficiently high to enable pin 166 to be tightened within piston 158 with less than a full turn, for example, a quarter turn. Pin 166 includes female threads 172 so as to permit connection of a threaded rod similar to rod 151. If desired, regular, non- interrupted threads may be employed. The hydraulic system for the clamping system described is shown schematically in Figure 10 andliUREAOMPI comprises a three-way valve 174 connected to a source of pneumatic pressure over line 176, an air over hydraulic booster 178 having a high pressure hydraulic output line 180 which connects with cylinders 92 (or cylinders 152) through quick disconnect coupler 182.The hydraulic bayonet clamping system described above operates as follows. Fixture 32 is floated on its film of pressurized air to the desired position, accurately located by means of locating pins 70 and then brought to rest on table 28 by interrupting the supply of pneumatic pressure to passageways 36. In the case of the embodiment shown in Figures 6-9, pins 128 are inserted through their respective openings 120 and pistons 196 and then turned 90° so as to be locked in place (Figure 6) . Blocks 184 are then set in place and slotted clamping bars 186 are placed over rods 151 and suspended between blocks 184 and fixture 32. Washers 188 are placed over the ends of rods 151 and tightened against clamping bars 186 by nuts 190. Downward pressure on clamping bars 186 is exerted by.admitting fluid under pressure into working chamber 108 which urges piston 96 and therefore pin 128 downwardly. If the fixture 32 is to be moved, the above steps are reversed and another pair of piston and cylinders 92, 96 are selected. In order to prevent chips and shavings from collecting in openings 120, they are equipped with covers 192 when not in use.The embodiment of Figure 11 operates in a similar fashion to the embodiment just described except that pin 166 is screwed into piston 158. This embodiment has the advantage that a smaller piston and cylinder may be employe .A manual clamping embodiment is shown in Figure 13 and comprises a pin 194 identical to pin 128 received in a stepped opening 196 in table 198. ' The female element 200, which has an internal horizontal section BUREAtTOMPI ™p° similar to piston 96, is threaded into a downwardly facing bore 202 in table 198. Clamping bar 204 is pulled downwardly by tightening nut 206 on threaded rod 208, which is in turn threadedly connected to pin 194.A further modification of the present invention is illustrated in Figures 14 and 15 and comprises a pin 210 similar to pin 194 received in a stepped opening 212 in table 214. The female element 216 is similar to element 200 and threaded into bore 218 and engages the end of pin 210. Hydraulic cylinder 220, which is similar to the one shown in Figures 6 and 11, is received over rod 222 between nut 224 and clamping bar 225 and spacer 223. When energized, cylinder 220 exerts downward force on bar 225 through spacer 223- so as to clamp a workpiece 226 as shown __ in Figure 14. All of the clamps are preferably ener¬ gized simultaneously.While this invention has been described as having a preferred design, it will be understood that it is capable of further modification. This application is, therefore, intended to cover any variations, uses, or adaptations of the invention following the general principles thereof including such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains, and as may be applied to the essential features herein¬ before set forth and fall within the scope of this invention.IΪΛFREOMPI .A*. WIPO | WHAT IS CLAIMED IS:1. In a machine tool having a table with an upper surface adapted to support a workpiece or work- piece fixture thereon, the improvement being appara- tus for clamping the workpiece or workpiece fixture to the table comprising: a plurality of openings in said table, removable cover means for covering selected ones of said openings, a plurality of first clamp elements being mounted within said table respectively below and ac¬ cessible through said openings, a second clamp element adapted to be remov¬ ably inserted in a selected said opening and including means for selectively, mechanically interlocking with the first, clamp element mounted below the selected opening, ' *- a third element on said second clamp element adapted to engage a workpiece or workpiece fixture supported on said table surface, and means for drawing said third element toward said table surface whereby a workpiece or fixture supported on said table and engaged by said third element will be clamped therebetween. 2. The apparatus of Claim 1 wherein said means for interlocking said first and second clamp elements includes means whereby interlocking is effected by first engaging said first and second elements and then rotating said second element. 3. The apparatus of Claim 2 wherein said means for interlocking includes: a bore in each of said first elements in alignment v/ith its respective said opening, and lug means on said second element adapted to be inserted through said bore and to interlock with said first element when said second element is turned in said opening.4. The apparatus of Claim 3 wherein:' said bore has a long dimension and a short 5 dimension each generally parallel to said table surface, said lug means has a long dimension and a short dimension each generally parallel to said table surface when positioned in said opening, said lug long and short dimensions are less 0 than or equal to said bore long and short dimensions, respectively, and said lug long dimension is greater than said bore short dimension.5. The apparatus of Claim 2 wherein said second element is a pin, and said means for interlocking 5 includes interrupted high pitch threads on said pin and a correspondingly ^threaded socket in each of said first elements aligned with their respective said openings.6. The apparatus of Claim 1 wherein said means 0 for drawing said third element towards said table includes a power actuator operatively connected to said first element.7. The apparatus of Claim 6 wherein said means for drawing said third element includes a fluid actuated 5 piston. .8. The apparatus of Claim 1 wherein*said means for drawing said third element toward said table includes a power actuator engaging said third element from* * above. 0 9. The apparatus of Claim 8 wherein said third .element includes a pin extending upwardly from said table and a clamp bar adapted to engage a workpiece or fixture, and said power actuator is a hydraulic cylinder device received over said rod and in engagement 5 with said clamp bar.BUREOMPI1 10. The apparatus of Claim 1 including: a work¬ piece fixture supported on said table, said fixture ha ing a downwardly facing lower surface, and means for supplying pneumatic pressure between said table and fixture surfaces for floatingly supporting said fixture on said table to permit free movement of the fixture thereon.11. The apparatus of Claim 10 wherein said cover means are substantially flush with said table surface when in place.12. The apparatus of Claim 1 wherein said means for drawing said third element toward said table sur¬ face comprises fluid actuators mounted within said table beneath the upper surface thereof, one of said pistons or cylinders being stationarily secured to said table, and the other of said pistons or cylinders - being fluid actuated, said first clamp elements being connected respectively to said the other of said pis¬ tons or cylinders. 13. The apparatus of Claim 12 wherein said sec¬ ond clamp element comprises a pin and said means for mechanically interlocking includes respective bores in said the other of said pistons or cylinders and lug means on said pin adapted to be inserted into any one of said bores and interlock with the respective said the other of said pistons or cylinders when said pin is turned.14. The apparatus of Claim 12 wherein said sec¬ ond clamp element is a pin and said means for mechan- ically interlocking includes high pitch threads on said pin and correspondingly threaded sockets in said the other of said pistons or cylinders.15. The apparatus of Claim 12 including a slot in said table positioned beneath and parallel to said table surface, and a mounting plate slidably received^UREX*/ OMPI in said slot, at least some *of said fluid actuators being mounted in said plate, said plate and said some of said fluid actuators being removable from said table as a unit. | BERGMAN R | BERGMAN R |
WO-1979000118-A1 | 1,979,000,118 | WO | A1 | XX | 19,790,308 | 1,979 | 20,090,507 | new | B62D49 | null | B62D33, B62D49, B62D55, E02F3, E02F9 | B62D 33/063, B62D 49/06D3, B62D 55/02, E02F 3/28S2, E02F 3/30K, E02F 9/02, E02F 9/16M | TRACTOR | A tractor having a subframe (10) to which a telescoping arm (13) is vertically and horizontally pivoted, and the driver's cab (14) is connectable to the arm (13) to permit being placed in any desired position. The telescoping arm (13) is extensible from a length smaller than that of the subframe (10) to a length considerably in excess of that of the subframe (10), whereby the cab can be mounted on the subframe as well as in different locations about and above the subframe (10), say behind an implement (22) towed by the tractor. The drive unit (12) of the tractor is readily detachably connected to the subframe (10). | TRACTORThis invention relates to a tractor, particular¬ ly for use in agriculture, comprising a subframe sup¬ ported by wheels, caterpillar tracks or a combination thereof, engine and transmission means on the subframe for propelling the tractor and driving the implements coupled to it, and adriver's cab connected to the sub¬ frame.When a conventional tractor is driven without any implements coupled to it the tractor offers the driver a good driving position, but when implements are drawn, for instance in ploughing, the driver must constantly keep wath both forwardly and rearwardly and therefore occupies a semi-twisted posture which in time ..is extremely tiring and most trying to the body. It has proved that such a posture results in occupational injuries, particularly spinal trouble. The problem is known to all persons occupied in agriculture and gene¬ rally considered- insoluble inasmuch as the driver must • direct his attention in diametrically opposite direc- tions.There is another problem associated with tractors, namely the many accidents which according to statistical sociormedical investigations happen to about 25% when the drivers step into or out of their cabs.. To climb on to and step down from a tractor is becoming ever more difficult the larger and higher the tractors, and even if improvements are made, the problem becomes mor-0-- and more serious.A further problem of the increasing tractor and pertaining implement sizes is that they most unfavour¬ ably compact the soil. This soil compaction takes place 5 both in the surface layer and in the sub-soil. The com¬ pacted surface layer is broken up at the treatment of the soil (ploughing, harrowing, etc.) whereas the com¬ paction of the sub—soil is not affected by the treat¬ ment of the soil. Both types of compaction alter the10 natural consistency of the soil organism in different ways. Particularly serious is the compaction of the sub-soil, which reduces the drainability of the soil and disturbs the capillary forces which lead water upwards to the plants.15 The object of the present invention is to solve the problems of the tractor drivers in a structurally simple manner and.at the same time at least partially reduce the soil compaction problem. • ~ - Another object of the invention is to manufac-20 ture .a tractor which is more useful than conventional tractors.These and further objects of the invention are attained in that both the drive unit and the cab are d'etachably connected to the subframe and that the cab25 is connectable with the free end of a telescoping arm.With a tractor built in this manner and particu¬ larly if the cab is vertically pivotally connected to the telescoping arm and the latter in turn is ver¬ tically and horizontally .pivoted to the subframe and-30- is extensible from a length smaller than that of the subframe to a length considerably greater than that of subframe, the driver can dispose the driver's seat in a position suitable for each individual implement, for instance behind or obliquely behind a plough, and can35 thus occupy a convenient sitting position and check both the direction of travel and the plough only by raising and lowering his eyes. When the tractor is driven for transport purposes the invention makes it possible to place the cab at a location prepared for it on the subframe and lock it, if necessary. A further advantage gained with a tractor constructed in this manner is that the cab during operation of the tractor normally is spaced from the subframe, whereby the risk of accidents is diminished. As the cab is pivotal and vertically adjustable the driver can enter and also step out of the cab directly from the floor thereof to the ground without being forced to climb, if only the cab is swung laterally outwards and lowered to ground level. It will thus be possible to eliminate accidents in connection with the driver's entering and leaving the cab. The suspension of the cab in a telescoping arm also entails a considerable reduction of the vibrations normally occurring on a tractor. The tractor can also be used for other purposes than purely agricultural work, such as painting of facades etc.Being detachable from the tractor, the drive unit can also be used for other purposes, such as ' to drive a combine harvester, whereby the machine -investments can be reduced without any of the dis¬ advantages that have been experienced hitherto when a single power source, such as a tractor, is employed to drive all the machines to be found on a farm.• The drive unit serves to drive the tractor im¬ plements and to propel the tractor with the implements- coupled thereto. The unit is preferably equipped with legs on which caterpillar tracks are mounted. The legs can be hydraulically raised and lowered so that the tracks can be elevated, for instance when the tractor is driven on roads. The caterpillar tracks, which reduce soil compaction, can be driven by hydraulic motors, and if the wheels of the tractor as well as the caterpillar tracks thereof are drivable, the cross-country mobility of the tractor will be almost unlimited. The caterpillar tracks, however, can also be idling, in which case they; - only serve to reduce the pressure exerted by the tractor per surface unit. The drive unit can of course also be used to drive stationary machines, for instance with the aid of hydraulic motors. 5. An embodiment of the invention will be described in greater detail below with reference to the accompa¬ nying drawings in which:Fig. 1 is a diagrammatic perspective view of a tractor according to the invention in a suitable posi- 0 tion for being driven on roads;Fig. 2 is a corresponding view of the tractor according to the invention with the cab removed from the subframe when ploughing is effected;Fig. 3 is a view showing the tractor with 5 a cab attached to the subframe, and a bucket connect¬ ed to the telescoping arm of the tractor; ig. -4 is a side view of the tractor drive unit,Figs. 5 and 6 show the drive unit in various 0 driving positions.The illustrated tractor has a subframe 10 sup¬ ported by wheels- 11. The tractor is of an altogether • novel design which has no engine of its own but instead has- connecting means for a detachable drive unit 12 which will be described more in detail in the following. The wheels 11 of the tractor are driven by hydraulic motors which once the unit 12 has been connected to the tractor are coupled to the hydraulic pump of the unit. As shown in Figs. 4-6 the drive unit 12 comprises- a frame 30 on which are mounted an internal combustion engine 31, such a Diesel engine, and a hydraulic pump 32 driven by the engine. The frame 30 has one pair of legs 33 on each side. Each of said leg pairs supports a beam 34 on which wheels 35 or rollers are mounted. A caterpil¬ lar track 36 is placed about the wheels 35. The legs 33 consist of hydraulic piston and cylinder units which_0 PI^NATI can be protracted and retracted. The details associated with the drive unit 12 can be such as are available on the market, and the mounting of for instance the lags 33, the wheels 35 and the caterpillar tracks 36 can be performed in a manner well known to one skilled in the art.The drive unit is arranged to be mounted on a tractor with the aid of some simple fastening means of reliable function. The hydraulic pump 32 has a number of quick couplers (not shown) by means of which hydraulic hoses on the tractor are connected to drive the tractor as well as the implements coupled thereto. To drive the tractor proper at least one pair of wheels 31 can have' a hydraulic motor for each wheel or a hydraulic motor common to them. If all tractor wheels have individual hydraulic motors the latter can also serve to steer the tractor, but it goes without saying that hydraulic motors can also be arranged to turn one wheel pair in conventional manner. The wheels 35 of the drive unit can be idle so that the caterpillar tracks 36, when in the position illustrated in Fig. 2, only have the task of distributing the weight of the tractor over a larger surface, but said wheels 35 can also be driven like the tractor wheels 31, which will of course considerably increase the mobility of the tractor. A particular advantage gained with the described drive unit is that the caterpillar tracks can be raised by retraction of the legs 33, whereby the caterpillar tracks do not cause any problems when driven on roads, contrary to what is at present the case with caterpillar tractors. A telescoping arm 13 is mounted with its one end on the tractor subframe 10 and carries at its other end a driver's cab. The cab 14 is- disposed in a U-shaped member 15 which is connected to the arm 13 at 16. The U-shaped member 15 is vertically pivoted to either the arm 13 or the cab 14 so that the latter always occu pies a horizontal position regardless of the inclina¬ tion of the arm 13. The cab 14 has a roll bar 17 ex¬ tending all around it, and preferably the arms of the U-shaped member are connected to said roll bar. The 5 telescoping arm 13 is vertically pivoted at 18 to a supporting means 19 which in turn is horizontally pivoted to the subframe 10 by a bearing device 21. A hydraulic cylinder and piston unit 20 is provided between the supporting means 19 and the arm 13 to swing said arm i310 in the vertical plane. A hydraulic motor is arranged to swing the arm 13 in the horizontal plane. The arm 13 has three telescoping parts but can of course have a greater or smaller number of such parts. Hydraulic piston and cylinder units are arranged to shift the15 parts of the arm 13 in relation to each other and, like the hydraulic cylinder and piston unit 20 and the hydraulic motor, they are coupled to the hydraulic pump. . _ of the drive unit 12.It will appear from the drawings that the arm20. 13 with the parts retracted into each other is of a length smaller than that of the subframe 10 so that the cab 14 can' be placed in the position 23 reserved for it on the subframe and, if desired, locked in this position. With the parts of the arm 13 fully protracted25 the arm is of a length considerably in excess of that of the subframe 10.In the cab 14 is mounted a control panel with control means which are coupled by means of iines run in the interior of the arm 13 to a servo mechanism on30 the subframe 10 so that all requisite movements can be controlled from the cab 14. The control panel and the driver's seat are preferably movable together at least, through 180 so that the driver's seat and the control panel can be swung from a 'position used in towing35 implements to a position used for instance when the tractor is driven on roads, as shown in Fig. 1.The most important advantage gained by the trac-_ 0MPI 5 ?NATl tor according to the invention will immediately be rea¬ lized from Fig. 2. According to this Figure, the tractor driver can now cause the cab 14 to occupy such a location that he is able, say on ploughing, to observe the direc- tion of travel as well as the plough without turning his body in any way. Another advantage associated with this suspension of the driver's cab 14 is that the'usua vibrations can be reduced considerably. The risk of accidents is likewise reduced. The versatility of the tractor will also appear from Fig. 3 in which the tractor cab 14 has been placed and secured in its position 23 while a bucket 24 is pivotally mounted between the arms of the U—shaped member 15 of the tele¬ scoping arm 13. A hydraulic piston and- cylinder unit for pivoting the .bucket 24 is coupled between the upper edge thereof and the U—shaped member 15.The tractor according to the invention can also be used for entirely new tasks, such as facade painting, tree trimming or cutting etc., which have hitherto been performed with the aid of scaffoldings or special crane trucks or lorry—mounted cranes. Of particular importance is the reduced soil compaction attained by the tractor according to the invention. | CLAIMS1. A tractor particularly for use in agriculture, comprising a subframe (10) supported by wheels (11) , a drive unit and transmission means on the subframe for propelling the tractor and driving the implements (22)'5 coupled to the tractor, and a driver's cab (14) connect¬ ed to the subframe (10) , characterised in that both the drive unit (12) and the cab (14) are detachably connect¬ ed to the-subframe. (10) and that the cab is connectable with the free end of a telescoping arm (13) .10. 2 .~ A tractor as claimed in claim 1, characterised in that the cab (14) is- vertically pivoted to the telescoping arm (13) which is vertically and horizontally pivoted to .the subframe (.10) .3. A tractor as claimed in claim 1 or 2, characte— 15 rised in that the telescoping arm (13) is- extensible from a length smaller than that of the subframe (10) to a length considerably in excess of that of the subframe (10) . . A tractor as claimed in any of the preceding claims, characterised in that the driver's seat and the20 control panel are pivotal through at least 180° in the - - cab (14) .5. A tractor as claimed in any of the preceding claims, characterised in that the tractor is hydraulically driven.25. 6. A tractor as claimed in any of the preceding claims, characterised in that the drive unit (12) consists of a drive motor (31) and a hydraulic pump (32) coupled thereto, said drive motor and said hydraulic pump being mounted on a frame (30) , that the frame (30) has at least one pair of legs (33) on each side and that a caterpillar track (36) is mounted on each pair of legs.7. A tractor as claimed in claim 6, characterised • in that the length of the frame legs (33) of the drive unit (12) is adjustable with the aid of hydraulic piston and cylinder units. 8. A tractor as claimed in claim 6 or 7, characte¬ rised in that the legs (33) are formed by hydraulic piston and cylinder units.9. A tractor as claimed in any of claims 6-8, characterised in that the caterpillar tracks (36) are drivable by means of hydraulic motors. 10~. A tractor as claimed in any of claims 6—8, characterised in that the caterpillar tracks (36) are idle and that the tractor has at least one pair of wheels (21) each of which- is drivable by its own hydrau- lie motor, or a hydraulic motor common to said pair of ^wheels. | BROBERG P | BROBERG P |
WO-1979000122-A1 | 1,979,000,122 | WO | A1 | EN | 19,790,322 | 1,979 | 20,090,507 | new | G01N21 | G01N33, G01N21 | G01N21, G01N31, G01N33 | G01N 21/00, G01N 31/22, G01N 33/00 | IDENTIFICATION OF HAZARDOUS NATURE OF UNKNOWN MATERIALS | Means are provided to identify environmental hazards of unknown chemicals by people unskilled in chemistry, e.g. firemen and policemen who often have to deal with spillages of unknown chemicals in e.g. road accidents. The hazards are classified as corrosiveness, explosiveness, flammability and toxicity. A portable kit is provided and colour changes of chemical agents is the preferred means of showing the presence of a hazard. Some of the agents are new, and are claimed per se. | IDENFICATION OF HAZARDOUS NATURE OF UNKNOWN MATERIALSThis invention is concerned with the identification of the hazardous nature of unidentified materials, usually solids, or liquids or mixtures thereof. Typical examples of areas of use of the invention are spillages of materials from road vehicles e.g. tankers, checking water supplies, trade effluent and waste tips, unknown materials in stores, warehouses etc.Techniques exist to identify the hazardous nature of unidentified materials and these are based on first identifying the material itself and then from that information consulting the text¬ books to learn of the associated hazards. These operations can however be time-consuming, require skilled people to carry thøn out and can often only be done in a laboratory.So far as is known, the only example of a test kit for use by unskilled laboratory technicians to identify the hazardous nature of an unknown material is disclosed in British patent specification 1 388 221, which provides a kit for a layman to identify a narcotic or psychotropic substance e.g. hashish, cocaine, opium, heroin etc. In that kit the material is reacted with a test strip impregnated with a reagent solution and the substance identified according to the presence and degree of a colour change.It might be thought that the HAZCHEM code of a composite label would have solved the problem. However this is not the case since, in Great Britain at least, the code is only compulsory for certain vehicles and in many countries no code is available at all.- ϋ REATTOMPl The invention is based on the realisation that very often the first person required to handle an. unknown material lacks the appropriate skills to identify the material and its hazards and ther is a need to provide him with some means of identifying the hazards so that he can treat the material appropriately. For example, when a firεrTan first meets an unknown spilt liquid he needs to know whether he can wash it into the drains without health risks to the population irrespective of whether the liquid contains lead, nickel, copper, arsenic, antimony, bismuth or chromate. He also needs this inforrration quickly, and cannot delay until a saπ le is analysed by a skilled technician in a laboratory.According to the invention there are provided means for identifying the presence of an environmental hazard in an unknown røterial and suitable for use by operatives not skilled in chemistry e.g. firemen, policemen, is characterised by a plurality of agents each adapted to interact with a material having a particular hazard t give an indication of the presence or absence of that hazard.Flost preferably according to the invention, the agents are adapted to give a visual indication of the presence of the hazard, especially in the form of a pronounced colour change.The agents are preferably adapted to indicate the following hazards a) whether the rraterial is corrosive b) whether the material will react with water in a hazardous way c) whether the material is flaππBble or explosive d) whether the material is poisonousAgents for determining these hazards are preferably as follows:To test for corrosiveness, use is made of water [especially in the^^ £Aϋ OMPl_ case of solids) and also of a test paper (called paper E) comprising a filter paper impregnated with indicator dyes adapted to indicate the presence of acidsstronger than about pH 2, alkalis stronger than pH 12, bleaches and a reducing poison. It has been discovered that Titan Yellow and Metanil Yellow, are both suitable in this context and surprisingly that when the Metanil Yellow is of a low level of activity unless they are.,used in substantially equal quantities and deposited together from an aqueous solution, the desired indicator reactions will not be obtained. For the most dramatic colour change it is preferable to have more Titan Yellow present. With such a paper, a violently corrosive material will make the paper go black, char or dissolve while many corrosive poisons will make the paper change to a brown tan colour, a corrosive bleach will make the paper change to white, a corrosive acid will rrake the paper change to a violet-purple ■ colour and a corrosive caustic will rrake the paper change to an. orange red colour.The reaction with water can be tested using a sample of the unknown material with water in a vial supplied with the kit. Liquids which are irrmiscible in water and float upon water may be regarded as likely to be flammable while liquids which are irrmiscible and sink beneath the water are likely to be organic poisons.Separate tests are used to determine the flammable or explosive nature of a solid or a liquid. In the case of a solid, flammability can be tested by contacting a small portion with a direct flame, preferably from a low pressure gas lighter e.g. as supplied with the kit. It is much preferred that the lighter be one which can be operated by a button since this can be done easily even when the operator, as recommended, is wearing gloves. In the case of a liquid, some of the liquid may be applied to a glass fibre strip which is exposed to the flame, and the behaviour on burning will indicate a fire hazard. To test for explosive risk, use is made, according to the invention, of an especially modified test tube having adjacent the lower end a hole -in its wall to act as a vent for explosive forces. The small sample is put into the test tube which is then heated with the hole uppermost and a sudden flash, puff of smoke, or pop will indicate an explosive risk. It is also important to identify materia which have the ability to oxidise and which- thereby aid or initiate fires in combustible materials. A suitable agent comprises a filter paper impregnated with e.g. starch and iodide and which when wet and in the presence of an oxidising agent goes blue, violet or purple.To test for poisons which are those most likely to be encountere and the specific nature thereof, reliance can be made on the results test embodying well-known chemical principles for example the fomrBti of sulphide precipitates by heavy metal poisons, the Prussian blue te for cyanides, and the ferric chloride reaction with phenols. From ti to time however other agents to identify poisons which presently are unusual may be included. The invention preferably includes means for the identification of the presently important groups of poisons. In addition use is πade according to the invention of further test paper and as follows:Test paper H coπprising a glass fibre filter paper impregnated with a copper sulphate solution will, when wetted by halocarbons and/or nitrogen containing organics such as aryl amines and nitriles, give a low pressure gas flame a distinctive purple colour indicative of an organic poison vapour.Test paper M coπprising a glassfibre filter paper impregnated with sodium acetate or the like in aqueous solution and a colour strip of p-dimethyleminobenzylidene-rhodanine deposited from solution in acetone will when exposed to aqueous solution containing mercury give a pink to violet colour and the same is sometimes true of silver, gol and platinum compounds. Given the information about the identity of the hazard then appropriate measures can be recommended.Preferably the means is provided in the form of a portable kit containing some apparatus by which the operator can take a small sample of the unknown material. In this way the unskilled operator can take a small sample and then withdraw from the possibly hazardous area to perform the tests with less risk of danger. The apparatus preferably is made of a relatively inert material such as polypropylene and is preferably a beaker of the type having a triangular rim by which samples can be scooped up.Instead of using test tubes which require some skill and a frame in which to stand, use is made of glass flat bottomed vials having a snap fit plastic lid. These may also serve to store samples of materials for later identification.The invention as thus discussed will not identify radio-active and biological hazards but the kit may include appropriate instruments and reagents to identify these particular hazards. The kit preferably also includes protective covers in the form of gloves, goggles and the like; and sets of instructions, incorporating suitable warning, to protect the operator from the hazards he is seeking to identify.The invention includes the means as defined, a kit containing such means and a method of testing, as new items of industrial use, Test papers E , H and M and a test tube modified as defined.An embodiment of the invention is illustrated by the following specific embodiment comprising a set of-instructions supplied with a kit containing the reagents and for use specifically by firemen. CONTENTS—MODULE 1 - SOLIDS1.0 Observation1.1 Test Strip E1.2 Water and Conversion to Liquid1.3 Heat1.4 Flame I1.5 Flame IIMODULE 2 - LIQUIDS2.0 Observation2.1 Test Strip E2.2 Water ' .2.3 Test Solution A2.4 Test Solutions B and C2.5 Test Solution C2.6 Test Solution D2.7 Flame I - Test Strip F2.8 Flame II - Test Strip G2.9 Flame III - Test Strip HMODULE 3 - SEPARATION OF SOLID AND LIQUIDMODULE 4 - ADDITION TESTS FOR SPECIFIC IDENTIFICATION4.1 Test Strip M4.2 Test Strip P4.3 Test Strip S ■MODULE 1 - SOLIDS1.0 OBSERVATION1fU RE4 OMPI Approach with care. Take a sample in a plastic beaker for testing. Do NOT enter dust clouds without protective apparatus. Move well away once the sample has been taken.The following are first indications - warning of possible hazards.. Only the subsequent tests are positive identification.Observation HazardBurning sensation in eyes Corrosive poison - keep away or choking sensationBitter odour Poison - keep awayMaterial smoking Severe fire hazard - keep awayFibrous appearance May be asbestos or other harmful silicateShiny or metallic Possible fire hazard Possible poisonPlastic-like Probable fire hazard1.1 TEST STRIP E (As defined above)Moisten one end of test strip - not too wet.Touch the solid with the strip.A colour change will develop in about one minute.Observation HazardFizzle and/or paper Strong corrosive goes black Dangerous with waterViolet-Purple Acid Orange-Red CausticBrown-Tan Corrosive poisonWhite Corrosive bleach1.2 WATER (AND CONVERSION TO LIQUID)Place a little solid in a vial: about as much as would cover a disc, 3 to 4 mm in diameter. Cautiously add water until the vial is half full. If there is a violent reaction, stop immediately. Swirl to mix the solid with the water.Observation InstructionReacts violently Dangerous corrosive - keep away from water, keep away from peopleDissolves (even part) Test liquid in module 2 (see noteFloats or sinks, but does Add nitric acid until the vial is not seem to dissolve even about 2/3 full. Swirl, and leave partially for at least 2 minutes before testing in module 2 (see notes).NOTESLeave the mixture in the vial, and carry on with fire hazard tests 1.3 to 1.5. Then use the liquid in the vial for tests 2.4 to 2.6 to determine poison properties. This applies even if none of the solid appears to have dissolved. If the mix is too dark for colour tests to be seen, use module 3 to clarify it before module 2. If the solid is flammable (tests 1.3 and 1.4) then this testO indicates if water can be used to extinguish a fire. As follows:Reacts violently NOFloats NODissolves YES Sinks YES 1.3 HEAT - TEST IN A WELL VENTILATED SPACE Place enough material to cover- a dot 3 to 4 rr in diameter in the bottom of one of the modified test-tubes. Hold the tube at an angle of 45 degrees with the side hole upwards. Apply a flame cautiously to the bottom of the tube. Heat more strongly if there is no reaction.Observation HazardSudden flash ExplosiveAudible pop or crack ExplosiveSudden puff of smoke ExplosiveColoured fumes Poison fumes on heating1.4 FLAME I - TEST IN A WELL VENTILATED SPACEIf the solid is in lumps, take a small piece in tweezers and cautiously apply a direct flame. For a powder or sludge, take a nichrome wire in its holder, and place 6 mm to 12 rrm into the material so that some sticks to the wire. If necessary, wet the wire, or make a loop. Cautiously apply a direct flame.Observation Hazard Burns easily FlammableBurns smokily Organic poisonGarlic smell Danger - ArsenicFibrous, does not burn Possibly asbestos or fibreglass or meltBurns, melts, drips .Flaπmrable - spreads fire1.5 FLAME TEST II - TEST IN A WELL VENTILATED SPACEPartly fill vial with clean water. Take a copper wire in its holder and heat in flame for 10 seconds. If the flame is coloured green or blue, the wire is contaminated. Either clean the wire, cut off the end or use new wire. When flame is not coloured, cool wire by dipping into water. Dip into material so that a srrall amount sticks to wire. Apply flame carefully for 10 to 20 seconds.Observation HazardSolid burns, then flame Organic poison goes green or blueSolid does not burn: Heavy metal poison flame gives blue flashesMaterial seems plasticj Usually PVC gives black smoke: flame goes greenSolid does not burn: Inorganic poison flame goes green ' MODULE 2 - LIQUIDS2.0 OBSERVATIONObserve from a distance. Approach cautiously. If any of the poison hazards given below are recognized, withdraw immediately. Take a sample in a plastic beaker for testing, if this can be done safely. Perform all tests well away from the original unknown material.Observation HazardVisible fumes from cold Strong corrosive: poison liquid vapourAcrid or choking smell Poison vapourBad egg smell Poison vapour - sulphideBitter smell Poison vapourSweet smell Probably flammableFruity smell Probably flammable2.1 TEST STRIP E (As defined above)METHOD 1Touch end of paper to liquid. If no colour develops in one minute, place a drop of water on paper so the two patches meet and wait a further minute for colour to develop.METHOD 2If liquid is highly coloured, tarry etc., place one drop on paper, turn over and look at back of paper for colour development. If no colour change occurs, place one drop of water on back of paper and observe as in Method 1.Observation HazardChars black or dissolves Strong corrosiveViolet-Purple AcidOrange-Red CausticBrown-Tan Corrosive poisonWhite Corrosive bleach2.2 WATERHalf fill a vial with water. Carefully add one drop of liquid using a transfer tube. If there is no violent reaction add several drops more and swirl, not shake.Observation HazardViolent reaction: fizzle Strong corrosive: dangerous or fumes with waterFloats, does not mix FlammableSinks, does not mix Organic poison (poison vapour)Goes milky Probably organic: possibly poison, possibly flammableMixes Use test 2.3 _, 2.3 TEST SOLUTION A (Reagent grade NaCl, coloured with rhodamine B)(Only necessary if the sample mixes or sinks in test 2.2 Otherwise go straight to test 2.4)Half fill a sample vial with Solution A. Add a few drops of liquid using a transfer tube. Swirl gently.Observation HazardFloats) does not mix • Flarrrrable organic poisonSinksj does not mix Organic poisonFloats, partially mixes (may Flarrrrable: (can be diluted with go milky) water)Mixes, going dense white Probably heavy metal poisonMixes Continue testing2.4 TEST SOLUTIONS B AND C(B is ferrous sulphate and sulphuric acid and ascorbic acid) (C is ferric chloride and hydrochloric acid)Quarter fill a vial with liquid. Add one drop of solution B and swirl. Add two drops of solution C and swirl. Ignore any white cloudiness. •Observation HazardBlue or blue-green colour CyanideDense black colour Poison - sulphide Purple colour Poison - phenolCloudy orange-brown Caustic - see noteNOTECaustic rray prevent detection of cyanide. If caustic is indicated, repeat the test as follows:Add one drop of liquid to a vial. Half fill with nitric acid and swirl. Add one drop of solution B and swirl. Add two drops of solution C and swirl. Blue or green indicates cyanide.2.5 TEST SOLUTION C (Ferric chloride and hydrochloric acid)Add one drop of liquid to a sample vial. Half fill with water and swirl. Add two drops of Solution C and swirl. If no reaction, add two more drops of Solution C. If still no reaction, add several drops of unknown liquid, swirling after each drop is added. Ignore any white cloudiness.Observation HazardPurple colour Crrβy fade) PhenolDense black colour SulphideRed (not orange) solid Possibly chromate or cloudiness2.6 TEST SOLUTION D (Sodium sulphide and potassium thiocyanate and sodium acetate and bromothyπ il blue)Half fill a vial with liquid. Add two drops of Solution DOMPI and swirl. If no positive reaction, add two more drops and swirl. Ignore any white cloudiness.Observation HazardBlack cloudiness Heavy metal poisonBlack cloudiness, fading Heavy metal poison to creamBright yellow cloudiness Heavy metal poisonOrange cloudiness Heavy metal poisonMurky green colour Poison - chrorrateRed colour Iron (ignore)2.7 FLAME I - TEST STRIP F (glassfibre filter paper) - TEST IN A WELL VENTILATED SPACEWet end of strip with liquid. Holding other end with tweezer not fingers, briefly touch the wetted end with the flame. If it does not catch fire, hold the flame on for longer.Observation HazardFlares up iπmediately Highly flammableCatches fire FlarrrrableBurns with difficulty CombustibleBlack smoke (whether Organic poison vapour combustible or not) • Green or blue tinge to Heavy metal poison flame (whether combustible or not)Red flame Ignore2.8 FLAME II - TEST STRIP G (Filter paper) - TEST IN A WELL VENTIL SPACEThis test is only necessary if there is some doubt about the flaππBbility of the liquid in test 2.7. It detects more subtle fire hazards. Completely wet middle of strip with a drop of liquid. Hold one of the dry ends in tweezers. Set fire to the other end: observe if flame continues through wetted area. If not, repeat, allowing one minute for the strip to partially dry out before applying a flame.Observation HazardWetted region burns CombustibleFlame flares up on wetted Potentially combustible and partially dried area2.9 FLAME III - TEST STRIP H (glassfibre filter paper iπpregnated copper sulphate) - TEST IN A WELL VENTILATED SPACECompletely wet one end of the strip with liquid. Hold ■ other end by tweezers. Apply a flame carefully to the wetted end. If the liquid does not burn well, hold the flame on for at least 30 seconds.Observation HazardPurple colour in flame Organic poison vapour W Green colour in flame IgnoreMODULE 3 - SEPARATION OF SOLID AND LIQUIDIf it is required to look at the solid and liquid portions of a mixture separately, this technique can be used. It rray also be useful if a liquid (either unknown or from test 1.2) is too cloudy for colour changes to be seen: in this case discard the solid and do tests on the separated liquid.METHOD1. Remove plunger from syringe.2. Place one filter disc inside the syringe (do not crease).3. Gently press disc to bottom with a transfer tube.4. Add 2 or 3 drops of liquid to wet the disc.5. Hold the syringe vertical (a support ring is provided). Half fill the syringe with the mixture.6. Replace the plunger, still keeping the syringe vertical.7. Carefully depress the plunger, collecting the filtered liquid in a sample vial.8. Remove the solid and the filter disc from the syringe using the nichrome wire and/or tweezers.9. Discard the syringe after use.10. Examine liquid as in MODULE 2. Examine solid as in MODULE 1. .MODULE 4 - ADDITIONAL TESTS FOR SPECIFIC IDENTIFICATION4.1 TEST STRIP M (as defined)a. FOR LIQUIDS: Hold strip M by the longer white end using tweezers. Touch the other end to the liquid - so that it soaks into the paper and rises up into the yellow coloured band.b. FOR SOLIDS: Convert to liquid as in test 1.2 then test as above.Observation HazardPink to violet colour MercuryNOTE; Silver, gold and platinum corrpounds may sometimes give a positive result. They are also poisonous.4.2 TEST STRIP S (Lead acetate paper)a. Place a drop of water on end of test strip S. Touch wetted end to solid or liquid. If no positive reaction, thenb. Place one drop of liquid, or a very small piece of solid, in a vial. Place test strip in vial. Add a few drops of-nitric acid. Do not inhale fumes.c. To confirm that an odour of rotten eggs is sulphide, moisten test strip with nitric acid, and leave in the fumes for a while. The more rapid the colour change, the higher the concentration.Observation Hazard Strip goes brown or black SulphideNOTE: Sulphide is as poisonous as cyanide. Avoid breathing fumes at all costs.4.3 TEST STRIP P (Ether peroxide test stick)a. ORGANIC LIQUIDS: Dip end of strip with cream pad into liquid for one second. If no colour change, wet the pad with one drop of water and wait a further 30 seconds.b. WATER MIXTURES: Dip end of strip as above. Colour should appear in 5 seconds.c. SOLIDS: ' Half fill a vial with water. Add a little solid and swirl. Wait 3 minutes before testing as in (b).Observation HazardTurquoise or blue colour PeroxideBlue colour turning brown PeroxideRapid green-brown colour Strong peroxideGreen (from yellow solution) Peroxide or chrαmateFIREMAN'S CHART - SOLIDS1.0 choking bitter smoking BA BA 1.1 black violet orange brown whiteFULL-V CONTAIN FULLCONTAIN-1.2 reacts dissolves floats sinksFULL-V FOG FOAM FOGDRY1.3 bang colour fumes V - E BA for FIRE1 .4 flares burns garlic black smokeV BA B<\ for FIRE<—FLAMMABILITY— — > CONTAIN1.5 green blue black & greenCONTAIN CONTAIN CONTAINNOTES:Instruction as from Instructions: in brief -BA breathing apparatus V violently reactive E consider evacuation FULL full protective clothingCONTAIN ' prevent from entering drains etc. FOG, FOAM, DRY extinguishing agent for fire controlFIREMAN'S CHART - LIQUIDS2.0 fumes choking bitter bad eggs fruity FULL-V BA BA BA BA CONTAIN- UROM 2.1 black violet orange brown whiteFULL-V FULL FULL CONTAIN FULLCONTAIN2.2 reacts floats sinks mixesN2.4 black purple blue/greenBA FULL BA CONTAIN yellow orange green CONTAIN CONTAIN CONTAIN CONTAIN2.7 flares burns combusts black smoke green/blue V FULL CONTAIN < FLAMMABILITY- CONTAIN2.8 burns flares2.9 purple FULL CONTAIN BUREAUO PI NOTES 1. Test 2.0 'fumes' initial action until further information is obtained.2. Test 2.1 'violet, orange, white' if subsequent tests do not give 'contain' then reasonable quantities may be diluted and run to drains. (Notify water authorities.)3. Test 2.3 'mixes' nay be diluted if other tests do not give 'contain'.ITU EOMPI | CLAIMS:-1. Means for determining the presence of an environmental hazard in an unknown material and suitable for use by operatives not skilled in chemistry, e.g. firemen, policemen and the like, characterised by a plurality,of different agents each adapted to interact with a material having a particular hazard and to give an indication of the presence or absence of that hazard.2. Means according to Claim 1 characterised in that the agents are adapted to indicate that a material is corrosive, explosive, poisonous or has the ability to oxidise or burn.>, Means according to Claim 1 or 2 characterised in that at least one agent is adapted to give a visual indication of the presence of the hazard.4. Means according to Claim J>, characterised in that the visual indication comprises a change of colour.5. Means according to any of Claims 1 to 4, characterised in that an agent to identify the corrosive nature of an unknown liquid material comprises a filter paper or like substrate impregnated with a mixture of Titan Yellow and Metanil Yellow deposited from an aqueous solution onto the paper.β. Means according to any of Claims 1 to 5, characterised in that the agent to identify the corrosive nature of an unknown solid material is water.7. Means according to any of Claims 1 to 6, characterised in that the agent to detect the explosive nature of an unknown material is a flame applied to a sample of the material in a test tube having adjacent the lower end a vent hole in its wall. 8. Means according to any of Claims 1 to 7, characterised in that the agent to detect the poisonous nature of an unknown material is adapted to form with the poisonous material a sulphide, cyanide or phenol-chl ride complex.9. Means according to Claim 8, characterised in that the unknown material is a mercury derivative and the agent to detect the mercury comprises sodium acetate deposited from aqueous solution onto a filter paper or like substrate which also has a colour strip formed of p-dimethylaminobenzylidene rhodamine deposited from solution in acetone, which strip changes colour on contact with mercury.ID. Means according to Claim 8, characterised in that the agent to detect the poisonous nature of an unknown organic material comprises a filter paper or like substrate impregnated with copper sulphate solution.11. Means according to any of Claims 1 to 5, characterised by an agent adapted to react to the radioactive nature of an unknown material.12. Means according to any of Claims 1 to j5* characterised by an agent adapted to react to the biologically hazardous nature of . an unknown material.13. A portable container for field use characterised by means according to any of preceding Claims 1 to 12.14. A portable container according to Claim 13* characterised by the presence of a beaker of a relatively inert plastics material which beaker has a triangular rim. 15. A portable container according to Claim 13 or 14, characterised by the presence of at least one flat bottomed vial having a snap fit lid,lβ. A container according to any of Claims 13 to 15 characterised by the lighter operable by a button.17. A method of testing for the presence of an environmental hazard in an unknown material characterised by reacting the unknown material with a means according to any of Claims 1 to 15.18. For use as an agent to indicatethe presence of a strongly acidic or caustic material, a filter paper or like substrate characterised by being impregnated with a mixture of Titan Yellow and Metanil Yellow deposited from an aqueous solution.19. For use as an agent to indicate the presence of halo- carbons or nitrogen containing organic compounds, a filter paper or like substrate characterised by being impregnated with a copper sulphate solution.20. For use as an agent to indicate the presence of mercury, silver, gold, platinum or the like, a filter paper or like substrate characterised by being impregnated with sodium acetate or the like in aqueous solution and having thereon a colour strip comprising p-dimethylaminobenzylidene-rhodamine deposited from solution in acetone.21. For use in analysis of unknown materials a test tube characterised by having at or adjacent the closed end a vent hole in the side wall. | FOSPUR LTD; KEEN R; PITT M | KEEN R; PITT M |
WO-1979000123-A1 | 1,979,000,123 | WO | A1 | XX | 19,790,322 | 1,979 | 20,090,507 | new | B61H13 | null | B60T8, F16K17 | B60T 8/18G | A CHANGE-OVER VALVE,PREFERABLY FOR A RAILWAY VEHICLE | A change-over valve (or a so called empty-load valve), preferably for a railway vehicle, having a valve device (16, 31-35) opening or closing a pneumatic passageway depending on the position of a mechanical operating system or in other words the load on the vehicle. In order to improve the working range of the external operating arm (4) and the exactness of the change-over point the operating system is a force transmitting chain from said operating arm to the valve device (16, 31-35) via a spring (9), a knee lever (13), and a valve operating rod (14) in such a geometrical way that the axis of the spring is substantially perpendicular to the valve operating rod. | A change-over valve/ preferably for a railway vehicleThis invention relates to a change-over valve, pre- ferably for a railway vehicle, comprising a valve device for emitting one of two different pneumatic pressures at a constant inlet pressure depending on the position of a mechanical operating system operated at increasing load on the vehicle.Many such change-over valves are earlier known. Good examples of the prior art are US 3 291 265 and 4 010 771. In the former case the operating system for the valve device comprises an axially movable operating rod, which' is arranged axially in series with the valve device. This means that great forces can be transmitted to the valve device from the vehicle underframe via the push rod, which forces can be detrimental to the valve device. It is also difficult to mount tui_=. type of change-over valve pro¬ tected against external influences of for example dirt, water, ice, and heat.The axial movements of the push rod in this change¬ over valve give also rise to severe sealing and wear problems. It is thus advantageous to replace this axial movement by a rotational movement relative to the change¬ over valve itself. Such an alteration, which is known for^ OMPI example through the second patent mentioned above, makes it also possible to mount the change-over valve more protected from external influences.-- • A common drawback with both the known change-over5 valves is that only comparatively small movements of the axially movable operating rod or the rotatable operating arm respectively are possible. Another drawback is a less satisfactory exactness as regards the change-over point for the valve.10 The main object of the invention is to obviate these and other drawbacks and to accomplish a small-size, cheap and reliable device only requiring maintenance, after long service periods.This is according to the invention attained in that15 the operating system comprises as a force transmitting chain an external operating arm on a shaft rotatably arranged in a valvehousing,an operating compression spring, which is arranged substantially prependicular' to said shaft between a bridge thereon and a first arm of a knee20 ' lever, which is pivotally movable around its knee and which with its second arm is arranged to act on a valve operating rod, which is substantially parallel to said first knee lever arm and the bridge.In order to make adjustment of the play between the2.5 bridge and the operating rod possible the operating spring is guided by a spring rod, which extends through the bridge and the effective length of which may be adjusted.It is preferred only to allow movements depending on a change of the load on the vehicle to reach the valve30 device. Other short-term movements may be transmitted to the operating arm under operational conditions due to the normal springing of the vehicle or rocking of the vehicle in certain cases. According to the invention the valve operating rod is provided with a damper preventing fast35 rod movements.U3O In the practical embodiment the valve operating rod is provided with a diaphragm type piston, which is movable in a sealed damper housing and has a restricted through opening for allowing the air confined in the housing to slowly pass from one side of the piston to the other. The opening is defined between a hole in the piston and a pin loose in the housing.It is important to note that the dampening effect solely comes from air. In this way a simple but yet highly effective design is attained.In the practical embodiment there is a rod return spring of compression type between a valve operating rod flange and the valve housing biasing the rod towards its rest position with the piston against a damper housing wall.There is also a bridge return spring between the housing and the bridge biasing the bridge towards a rest position against abutments in the valve housing.The dimensioning of the different parts of the operat- ing system is such that the total ratio , between a roller at the .end of the operating arm and the valve operating rod is in the order of 2:1.The invention will be described in further detail below reference being made to the accompanying drawings, in which Fig. 1 in a side view shows a change-over valve . according to the invention. Fig. 2 is a schematic repre¬ sentation of the working principle of the valve. Fig. 3 is a view of the valve with its cover removed but also with some parts sectioned for better clarity, and Fig. 4 is a section substantially along the line IV-IV in Fig. 3. A change-over valve 1 is attached to a mounting console 2, which in turn is attached to a rail vehicle body 3. An operating arm 4 is rotatably connected to the change-over valve 1 and extends towards a side-frame 5 of the vehicle bogie. The arm 4 is provided with a roller 6 for cooperation with the side-frame 5. In the shown rest position with the vehicle empty there is a certain distance, say 20 mm, between the side-frame 5 and the roller 6 for preventing small movements of the side-frame from affecting the change-over valve. When the vehicle is loaded the distance between the vehicle body 3 and the side-frame 5 will decrease, which means that the arm 4 will rotate in counter-clockwise direction after exces- sion of the shown distance between the side-frame 5 and the roller 6. A maximum movement of the arm 4 and its roller 6 to the dash-dotted position of 100 mm (in the vertical direction) must be possible. In the shown- case the vertical distance in the rest position between the parts 3 and 5 is 260 mm. As appears from Fig 1 the effective length of the arm 4 may be adjusted due to its releasable connection to its shaft 7.In the schematic representation of the valve 1 in Fig 2 the parts 4-7 may be recognized from Fig. 1. The other parts now to be mentioned under reference to Fig. 2 are further described below under reference to Figs. 3 and 4.The operating arm 4 is part of a double-armed lever, whose other arm is a bridge 8 acting downwards in Fig. 2 on a prestressed helical compression spring 9, called an operating spring. The spring 9 is arranged around a spring rod 10, whose effective length may be adjusted by means of an adjustment nut 11 and whose lower end provides a support for the spring 9. There is an abut- ent 12 defining the angular rest position for the operating arm 4 and the bridge 8.The force from the spring 9 acts on the horisontal arm of a knee lever 13, whose vertical arm acts on a valve operating rod 14, substantially perpendicular to the spring rod 10. It is obvious that this valve operat- ing rod 14 will move to the right in the drav/ing at a counter-clockwise turning of the operating arm 4 under -: the influence of a movement upwards of the bogie side- frame 5. The valve operating rod 14 is at. its left hand end provided with a damper 15 to be described more detailed below under reference to Figs.3 and 4. At its right hand end the valve operating rod 14 is arranged to co¬ operate with a three-way valve 16 spring-biased to its 0 shown rest position, in which fluid supplied through an inlet 17 will be prevented from reaching' an outlet 18, which in turn is vented to the atmosphere. In its operated position (not shown) the valve 16 will allow passage of fluid from the inlet 17 to the outlet 18. 5 This means that in the shown rest position of the change¬ over valve 1, corresponding to an empty vehicle, atmospheric pressure will prevail in the outlet 18, whereas in the outlet 18 the same fluid pressure will • prevail as in the inlet 17, when the vehicle is loaded 0 to a certain extent or in other words when the operat¬ ing arm 4 is turned in its counter-clockwise direction a certain angle.A return spring 19 is provided for the valve ■ • operating rod 14. 5 Referring now specifically to Figs. 3 and 4 for a more detailed description of the change-over valve 1, it has a housing 20 with a cover 21 attached thereto.The operating arm shaft 7 is properly journalled in the housing and extends out of the housing 20 with30 its right hand end as shown in Fig. 3. The bridge 8 is attached to the shaft 7 by means of bolts 22. The abutments 12 for defining the angular rest position for the shaft 7 are formed as integral parts of the housing 20. The spring rod 10 is provided with spring supports 10 and is tapered downwards for cooperation with a corresponding notch in the knee lever 13, as appears from Fig. 4. At its opposite end the spring rod 10 is threaded for receiving the adjustment nut 11, which after removal of a cap 23 is accessible from outside for adjusting the effective length of the spring rod 10.Between the bridge 8 and the housing 20 is also arranged a return spring 24 of the helical compression type with its centre line in the same plane as that of. the operating spring 9, i.e. the plane of Fig. 3. The return spring 24 is guided and supported by a spring support 25, and there are projections 8 on the bridge.8 for ensuring the proper position for both springs 9 and 24 relative to the bridge 8. The return spring 24 will bias the bridge 8 towards the abutments 12 and thus the operating arm 4 towards its rest position as shown in Fig. 1. '•The knee lever 13 is rotatably journalled on a shaft 26 (Fig. 4) mounted in the housing 20 and a hous¬ ing bracket 20 . The fork-shaped upper end of the knee lever 13 is placed astraddle of the valve operating rod 14 and cooperates with a flange 14 thereon. The rod return spring 19 of compression type is arranged between the housing 20 and the rod flange 14 .The valve operating rod 14 is, as appears from Fig. 4, axially movably supported near its left end by the housing 20 and near its right end by a damper cover 27, and there are ordinary sealings in both instances. The damper 15 for the valve operating rod 14 referred to briefly above under reference to Fig. 2 is of the following design:A damper housing consists of the valve housing cover 21 and the damper cover 27, which is clamped- between the former cover and the housing 20 together with a. damper diaphragm 28. This diaphragm 28 is supported by backing plates 29 and is together with these attached to the valve operating rod 14. In the diaphragm 28 there is a circular hole with a metal bushing 28 for a pin 30, which is not attached to either of the covers 21 or 27 in order not to bind in any way. The diameter of the hole in the bushing 28 may be 0,05 mm larger than that of the pin 30, having a diameter of 1,5 mm. This means that the enclosed air in the damper will have to be forced through the narrow opening around the pin 30 at the movements of the valve operating rod , which thus.will be damped.The opposite end (the left hand end in Fig. 4) is arranged to cooperate with a valve body 31, which is sealingly biased against a valve seat 32 in the housing 20 by means of a valve spring 33 supported by a cover •34 attached to the housing 20. An inlet channel 17 extends to the compartment around the valve body 31, whereas an outlet channel 18 extends from the compart- ment around the end of the valve operating rod 14. This rod 14 is provided with an axial bore 35, which connects the latter compartment with the interior of the housing 20 and, via a filter 36 in the housing wall, with the atmosphere. In the rest position shown in all Figures with the vehicle substantially empty and thus with the operating arm roller 6 substantially unaffected by the bogie side- frame 5 the valve body 31 will be sealingly held against its seat 32. This means that a fluid pressure trans- mitted through the inlet. channel 17 will not reach the outlet channel 18, which instead will be under atmos¬ pheric pressure through the axial bore 35 in the valve operating rod 14 and the filter 36. If now, still with the vehicle substantially empty, the operating arm 4 will be moved up and down in an oscillating way due to rocking movements between the vehicle body 3 and the bogie side-frame 5 under operational conditions, sub¬ stantially no movement of the valve operating rod 14 -: will occur due to the dampening effect of the air trying- to pass the narrow opening between the pin 30 and the hole in the bushing 28 .When the vehicle is loaded to a certain extent, so that there is a permanent counter-clockwise turning of the shaft 7 due to the diminished vertical distance 0 between the vehicle body 3 and the bogie side-frame 5, this movement will be transmitted to the valve operating rod 14 via the bridge 8, the operating spring 9, the knee lever 13 and the rod flange 14 in a rate determined by the air damper 15. The operating rod 14 will lift the 5 valve body 31 from its seat 32 at the same time as the hole 35 will be closed. In this way the outlet channel 18 will be communicated with the inlet channel.17 in¬ stead of with the atmosphere, and the same pressure will prevail in the outlet channel 18 as in the inlet channel 0 17.Again under operational conditions rocking movements may occur between the vehicle body 3 and the bogie side- frame 5. These movements will however not be transmitted to the valve operating rod 14 due to the dampening effect .' of the damper 15.The inlet channel 17 is connected to a source for fluid (air) under a constant pressure, whereas the out¬ let channel 18 is connected to any suitable means (not further described here) for effecting a more powerful braking-of the loaded vehicle than of the empty one, i.e.. when the pressure in the inlet channel 17.prevails in the outlet channel 18 and not the atmospheric pressure.The dimensioning of the different parts in the practical embodiment, is such that.the total movement ratio between the arm roller 6 and the valve operatingΛ Wl rod 14 is in the order of 2:1, which means that a vertical movement of the roller 6 in the order of 20 mm would correspond to an axial movement of the rod 14 in the'-: order of 10 mm. It is, however, to be noted that the possible axial movement of the valve operating rod 14 is limited to about 5,5 mm in the practical embodiment, corresponding to a movement of about 11 mm for the roller 6. Vertical movements upwards of the roller 6 exceeding this measure 0 will only result in a compression of the operating spring 9. The change-over point for the valve will be reached after an axial movement of the rod 14 in the order of • 3,5 mm.The function of the adjustment nut 11 is to allow 5 adjustment (preferably at the manufacturing) of the play between the knee lever 13 and the operating rod flange 14 , so that the sum of all tolerances in the activating chain from the bridge 8 to the valve body 31 does no effect the position of the change-over point. 0 The damper 15 is designed to delay the movement of the valve operating rod 14 at least three seconds, which is enough, as the minimum frequency of the rocking move- . ment between the vehicle body 3 and the bogie side-frame 5 is between 0,5 and 1 cps. 5 The maximum possible vertical movement of the• operating arm roller 6, which as earlier stated shall be in the order of 100 mm, is determined by the distance between the bridge 8 (or rather its projection 8 ) and the spring support 25. | Claims :1. A change-over valve, preferably for a railway vehicle, comprising a valve device (16, 31-35) for5 emitting one of two different pneumatic pressures at a constant inlet pressure depending on the position of a mechanical operating system (4-14) operated at increas¬ ing load on the vehicle, characterized in10 that the operating system comprises as a force trans¬ mitting chain an external operating arm (4) on a shaft (7) rotatably arranged in a valve housing (20, 21), an operating compression spring (9) , which is arranged substantially perpendicular to said shaft between a15 bridge (8) thereon and a first arm of a knee lever (13) , which is pivotally movable around its knee and which with its second arm is arranged to act on a valve operat¬ ing rod (14) , which is substantially parallel to said first knee lever arm and the bridge (8) .-20 2. A change-over valve according to claim 1, characterized in that the operating spring (9) is guided by a spring rod (10), which extends through the bridge (8) and the effective length of which may be adjusted for adjusting-25 the distance between the bridge (8) and said first arm of the knee lever (13) .3. A change-over valve according to claim 1, characterized in that the valve operating rod (14) is provided with a 30 damper (15) preventing fast rod movements.4. A change-over valve according to claim 3, . characterized in that the valve operating rod (14) is provided with a diaphragm type piston (28, 29), which is movable in a 35 sealed damper housing (21, 27) and has a restricted through opening for allowing the air confined in the housing to slowly pass from one side of the piston to the other.5. A change-over valve according to claims 3 and 4, characterized in that the opening is defined between a hole' (28 ) in the piston (28, 29) and a pin (30) loose in the housing (21, 27).6. A change-over valve according to claims 1 and 4, characterized by a rod return spring (19) of compression type between a valve operating rod flange (14 ) and the valve housing (20) biasing the rod (14) towards its rest position with the piston (28, 29) against a damper housing wall (21) . 7. A change-over valve according to claim 1, characterized by a bridge return spring (24) between the housing (20) and the bridge (8) biasing the bridge towards a rest posi¬ tion against abutments (12) in the valve housing (20) . 8. A change-over valve according to claim 1, characterized in that the dimensioning of the different parts of the • operating system is such that the total ratio between a roller (6) at the end of the operating arm (4) and the - valve operating rod (14) is in the order of 2:1. | SAB IND AB; SEGERSTEN R; SEVERINSSON L | SEGERSTEN R; SEVERINSSON L |
WO-1979000125-A1 | 1,979,000,125 | WO | A1 | XX | 19,790,322 | 1,979 | 20,090,507 | new | B26D4 | B26D3, B26D4 | A21C15, B26D1 | A21C 15/04, B26D 1/15 | SHEET CAKE CUTTER | A sheet cake cutter is effective to cut a sheet cake disposed in a pan (7) having a surrounding rim (8). The cutter has a frame (9) supporting a conveyor belt (13) for horizontal advancement and on which the sheet cake pan is concurrently advanced. On a transverse shaft (34) mounted for rotation on the frame are preferably arranged at least a pair of cutter discs (33) having edge notches (32) therein. The cutter discs are disposed in registry with a predetermined space between them. The discs are set just to touch the bottom of the pan and with the edge notches spaced to interengage the rim. The cutter discs can be frictionally driven or shaft driven through a single-cycle clutch (54) from the conveyor drive. The clutch is manually or automatically actuated to engage the drive by a pan on the conveyor and in position for interengagement of the notches and the pan rim. There is a holddown roller (71) disposed in the space between cutter discs and set at a height just above the sheet cake in the pan. | SHEET CAKE CUTTERBRIEF SUMMARY OF THE INVENTIONIn the large-scale manufacture' of petits fours and like confections, it is customary to start with a large sheet cake; that is, a single layer of cake dough gener¬ ally baked in a rectangular pan within the confines of a rim extending around the pan edge. The large sheet cake is manually cut into a number of individual blocks, often squares, that subsequently are individually removed from the pan and are then decorated and otherwise finished. Manual cutting of the sheet cake into the individual por¬ tions is not only laborious but does not always result in even sections nor in sharply defined edges. There is consequently provided a machine into which the cus¬ tomary sheet cake in its regulation pan can be introduced and conveyed along a predetermined path. As it advances, the sheet cake is cut into a number of longitudinal strips by automatically working cutting discs, taking into account the edges or rims of the pan and effective to provide quite uniform cutting of the cake. After an initial traverse through the machine, the cake pan is re- introduced but at right angles to its first orientation so that the already-cut strips are again cut at right angles to the initial cuts resulting in the desired.rec¬ tangular or square finished pieces. Cutter discs are provided at predetermined spaces apart, and rollers-BUREAU OMPI between them serve to hold down the cake between the cutters. The cutter discs have edge notches interre¬ lated to the rim on the pan to clear the pan rim.. Some¬ times the cutters are positively driven in synchronism ':- • with the advancement of the conveyor and usually through the medium of a single-cycle clutch, which is automatic¬ ally actuated when the pan advances and is automatically stopped at the end of a cycle, ready for a subsequent operation. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGFIGURE 1 is a side elevation of a device pursuant to the invention, certain portions being shown in section on a vertical longitudinal plane..FIGURE 2 is a cross-section, the plane of which is indicated by the line 2-2 of FIGURE 1.FIGURE 3 is a detail view showing the arrangement of a roller between successive cutting discs.DETAILED DESCRIPTION For the handling of a sheet cake 6 contained in a 0 ■ pan 7 having upstanding edges 8 therearound, there is preferably provided a frame 9 on which is mounted a pla¬ ten 11. Just over the platen extends the upper run 12 of a conveyor belt 13. The belt extends around rollers 16 and 17, at the opposite ends of the machine, and has a return run 18. The individual rollers are mounted re¬ spectively on shafts 21 and 22, the former of which is preferably driven by a motor or comparable driving device, not shown, but effective to advance the upper run 12 in the direction of the arrow 23. 0 In one method of operating the device when the shaft 21 is propelled and the conveyor upper run is ad¬ vanced, the tray 7 is positioned thereon with the sheet cake 6 therein. The cake advances in the direction of arrow 23 until such time as the leading edge or rim 8 of 5 the pan comes into contact with the bounding edge 31 of a notch 32 formed in the edge of a cutting disc 33. A series of cutting discs 33 are arranged alongside each other on a shaft 34, each disc being spaced a' predeter¬ mined distance apart from the adjacent disc in order to leave an intervening space 36. The shaft 34 is mounted on uprights 37 and 38 upstanding from the frame 9. The discs are united to turn in unison with the shaft 34 and customarily are arranged or registered as shown in FIG- ■ URE 1.In advancing, the leading rim of the pan comes into contact with the edge of the notch 32 which gears with or turns over and clears the rim as the pan advances. The pan edge causes rotation of the disc 33, and the ra¬ dius of the disc is preferably such that the disc edge 39 is in light frictional contact with the bottom of the pan 7 as the disc cuts through the sheet cake therein. Some rotation is caused by frictional contact with the bottom of the pan. As the discs turn, the sheet cake is divided by a number of longitudinally extending cuts into individual, elongated pieces. The dimensions are such that as the trailing rim 8 of the pan approaches the disc, another notch 41 in the disc edge bounded by sides 42 and 43 substantially registers or gears with the trailing edge of the pan and permits the pan to pass without undue mechanical interference. Since the advancing pan is then free of the disc, the disc stops its rotation, substan- tially as shown in FIGURE 1, again in position for en¬ gagement with a subsequently advancing pan. In this way the sheet cake is automatically divided into a number of longitudinal sections.Following this, the sheet cake is removed with its pan from the upper run 12 of the conveyor and is reintro- duced into the machine after a ninety degree rotation. Again the sheet cake advances on the upper run of the conveyor. This time the same cutting action takes place by all of the discs except that the cuts are at right angles to and intersect the previously made cuts. The sheet cake is thus divided into a number of rectangles- 1REΛ ΓOMPI ^ WIPO Λ>, or, preferably, squares. The cutting job is thus com¬ pleted. Alternatively, the pan, after turning, can be run through a subsequent, similar cutter with the same or different cutter spacing and number, thus taking care of shapes other than square.Under some circumstances, it is desired to augment the rather simple mechanism just described by a power drive for the cutter discs.A drive chain 51 extends from a sprocket 52 on the drive shaft 21 and engages a clutch sprocket 53 forming part of a standard unicycle of single-cycles clutch 54, anchored on the frame through a torque arm 55. The out¬ put from the clutch is through a shaft 56. A reversing gear 60 connects the shaft 56 to a sprocket 57 in engage- ment with a chain 58. Likewise engaging the chain is a sprocket 59 on an auxiliary shaft 61 journalled on the frame. A slotted collar 62 is keyed on the shaft 61 and in one position meshes with the end of the shaft 34. When the collar is in the position shown in FIGURE 2, the shafts 61 and 34 are united for concurrent rotation but when the collar 62 is moved to the right in FIGURE 2 it is disengaged from the shaft 34. There is then no con¬ nection between the shaft 61 and the shaft 34.In the operation of this power arrangement, the pan 7 containing an uncut sheet cake is placed on the conveyor 13, as before, and advances in the direction of the arrow 23 until such time as the leading edge of the pan abuts a switch contact 66. This switch when closed is effective to energize the clutch 54 for one cycle of rotation. The effect is to connect the driving shaft 21 to the driven shaft 56 and so to the shaft 34. The loca¬ tions are such that the switch 66 is closed just as the advancing edge of the pan comes adjacent the first notch 32. The cutter discs 33 than rotate in unison as the pan advances, much as previously described, except that the discs are independently rotated without contact with the pan edge. As the pan advances and the cutting action takes place, the cutting discs 33 rotate one cycle. That the discs do not rotate more than that is insured by the operation of a cam 67 fast on the shaft 34. In the prop- er orientation of the cutting discs, the cam 67 comes into contact with and energizes a clutch switch 68 effec¬ tive to deenergize the clutch 54 at the end of one com¬ plete cycle. Thus, as the pan moves beneath the cutting discs and its trailing edge passes through the notch 41, the clutch 54 is again disengaged, thus stopping the cut¬ ting disc operation.Again, the pan can be removed, rotated ninety de¬ grees and reintroduced. When the pan passes the switch 66 the cutting discs are reenergized so as to make cuts at right angles to the first cuts. The pan is discharged as before. If the pan is not square, it can, after turn¬ ing, be sent through a similar, subsequent group of cut¬ ting discs properly set for the different pan dimension and for a different intercutter spacing, if desired.To make sure that the cuts are well made even through at a relatively high speed, I particularly pro¬ vide means in between the various cutter discs to insure that the severed cake squares or portions do not rise frictionally with the discs and get out of position. For that reason, in the intervening space 36 between each pair of discs, there is disposed a low-friction roller 71, preferably of Nylon, mounted on a bracket 72 for ro¬ tation about its own axis. The brackets are fastened to an angle frame 73 extending parallel to the shaft 34 and carrying adjusting screws 74 in engagement with the frame 9. By appropriate manipulation of the adjusting screws, the rollers 71 can be positioned with their lower edges just above the normal upper surface of the sheet cake 6. As the pan advances and as the cutters operate, any ten¬ dency of the sheet cake strips, squares or blocks to rise is defeated by the presence of the intervening rollers 71.- UREΛ ∑ΓOMPI i fr WIPO &>> After substantial use or at the end of a particular period of time, it is desirable to remove the cutter discs and wash them. This is readily accomplished by sliding •_- the coupling 62 or collar to the right to free the shaft 34. Then, by releasing set screws 76 and 77 which support the shaft 34 on the uprights 37 and 38, the shaft 34 with its attached discs can then be lifted vertically above the uprights 37 and 38. After cleaning, the discs and shaft can be restored to a proper elevation with the set screws 76 and 77 being tightened to hold the discs in position. Under some circumstances it is desirable to move the machinery without depending upon the switch 66. For that reason, in circuit with the operational mechanism of the conveyor 13 and of the clutch, there is provided a manual start switch 81 and a manual stop switch 82.When the start switch is energized, the mechanism is put into operation and when the stop switch is energized or operated, the mechanism is stopped.By these means there is provided a device for - cutting a sheet cake automatically into a number of separate pieces with the pieces being uniformly and cleanly cut and being held in position while the cutting is taking place and for subsequent removal. A relatively standard cake pan is utilized; and the mechanism is sim- .. pie, straightforward and readily maintained in a sani¬ tary and operable condition. | WHAT IS CLAIMED IS;1. A sheet cake cutter comprising a frame, a con¬ veyor on said frame adapted to advance on said frame a pan having a rim and containing a sheet cake, a cutter disc having therein an edge notch interengageable with said rim, and means on said frame for mounting said disc for rotation relative to said frame with said disc extend¬ ing into said pan and said edge notch in interengagement with said rim.102. A device as in claim 1 including means on said frame for driving said conveyor and for rotating said disc conjointly.3. A device as in claim 2 including means for • coupling to and uncoupling said means for rotating said disc from said means for driving said conveyor.4. A device as in claim 3 in which said coupling and uncoupling means is a single-cycle clutch.205. A device is in claim 4 including means actuated by a pan advancing on said conveyor for actuating said clutch.6. A device as in claim 4 including means respon-25 • sive to rotation of said disc for deactuating said clutch.7. A device as in claim 1 including a shaft, a plurality of said cutter discs disposed coaxially on said shaft with a predetermined axial space therebetween, and30 a roller mounted on said frame and disposed in said space.8. A device as in claim 7 including means for supporting said roller at a predetermined distance above said conveyor.- ϋREΛ iTOMPI.fr WIPO . | FANTASIA CONFECTIONS; FANTASIA CONFECTIONS INC | LAKATOS C |
WO-1979000128-A1 | 1,979,000,128 | WO | A1 | XX | 19,790,322 | 1,979 | 20,090,507 | new | B63C1 | B63B27 | B63B27, B63B35 | B63B 27/00, B63B 35/30 | ROTATING PONTOON | A pontoon shaped as a large floating cylinder with a hollow interior, receiving one or more vessels (21) can be overturned through its rotation. The walls of the pontoon are made up of watertight compartments (1-21) which provide floatation and enable rotation of the pontoon. Rotation of the pontoon can be achieved by displacing water (Figs. 20-24) successively from one peripheral watertight compartment to another (Figs. 1-6). This rotation can also be performed by means of external power (Figs. 26-30). An external platform (45) is attached to the pontoon through joints (42), keeping its normal upright position when the pontoon rotates. On the platform can be installed the engine room (53) as well as all the implements used to perform the pontoon anchoring, towing, and mooring. This accessory equipment can also be attached to a belt (66) surrounding the pontoon hull and fastened to stationary floatation tanks (79). To provide for the discharge of vessels in rainy days, two types of floating roofs (49) are disclosed. To remove the load fraction which remains inside the vessel holds after its overturning, a system of pushing panels (Figs. 7-9) inside the hold and a system of helicoidal hatch-feeders (35-36) are disclosed. | Specification of a Patent of Invention for ROTATING PONTOON .(a) TECHNICAL FIELD In the latter years, a remarkable advancement concerning port cargo handling systems has been observed all around the world.The general cargo (boxes, burdens, sacks, etc), which predominated till the 50*s, has been gradually replaced by containers, dry. and liquid bulk cargoes.Nowadays, in modern ports, ore and agricultural products are wholly loaded in bulk.On the other hand, we, in Brazil, have been giving an increasing importance to the utilization of fluvial transport in substitution to the terrestrial one, mainly when concerning the conveyance of ore and agricultural products. It happens not only because it is the cheapest way of transport, but also because it is one of the most adeq&afceeb systems to save money for the country, to provide competitive conditions to our products in the external market, and to face the oil worldwide crisis.Yet, port time periods required for loading and unloading must be made as short as possible so that this way of transport will achieve the desired development. Swiftness in this late operation is also an essential requirement for the satisfactory performance of our port system.Therefore, our naval industry, the fluvial navigation shipowners and the port and maritime official-gυREATTOMPI boards are,, by all means, searching effective.manners of speeding-pu. tha operation... C BACKGROUND ART Ports which operate mostly in unloading or transhipment of agricultural exporting products arriving in fluvial vessels, like the port of Rio Grande. (State of Rio Grande, BrazilL, are now using specific unloading places for this nature of. navigation and cargo, (dry bulkl, equipped with shore discharging facilities .and mechanized transportation of. materials to store. .However, in. these ports, the equipment.which has shown more efficiency to solve the problem is the transhipment pontoon. It executes the transference of load from the holds of fluvial vessels straight to the ocean going ship holds.The transhipment equipment,is.installed on the pontoon like a conventional ship hull.Basically-, these pontoons have.different processes of cargo handling. They can be abbreyiated. s .the three following processes or their combinations.^ pneumatic; mechanical-continual (bucket..unloaders, chain conveyors, endless screw, belt conveyors}.; mechanical-intermittent (crane with grab gearl. ; All these unloading methods are.still effected by some slowness, caused .mainly by the equipment speed limitation and by the need of hatch-feeding .in..the existing load of the fluvial vessel.Acceleration of the unloading speed, of fluyial vessels in ports, and the performance of port facilities concerning rapidity and simplicity in loading ships, are problems that have also been worrying the inventor for quite a long time.After elaborating many ideas and attempts in order to adapt the conventional methods and equipment to achieve that intent, the Author conceived a kind of rotating pontoon which is approached in this.report.• Ccj DISCLOSURE OF INVENTIONThe fundamental principle of the invention is the ■ conception of a long tubular, shaped pontoon, open at least at one of its ends. This structure can. turn about its longitudinal axis at any given angle.•¥o~tfe_tsAhappen, it is a basic condxtion that the as a circular or closed polygonal shape.or both, in the periphery, of which,, watertight compartments can be arranged;in such, a way that they can support the platform floating, no matter..its position, considering its own weight as well as the load it should contain. Once assured the floating circumstances of.the pontoon, its internal structure.admits a ay different arrangements according to the desired purpose.The pontoon size is also subordinated.,to this purpose and to the depth of water in the place, it should operate. Equally, there are many forms. of producing.rotation, some of which, will be described .later without considerations about their applications and limitations, for they are enumerated in.this text.The described characteristics give a remarkable.series of applications to the invention as, for instance, in the construction of dry-bulk-cargo transhipment pontoon, floating docks used in shipbuilding or in ship repairing, floating stores, etc.(dl BRIEF DESCRIPTION OF DRAWINGSThe attached 14 sheets of drawings contain .30 Figures.Figs. 1 and 2 show schematic cross sections of the pontoon flooded only with the tanks located below waterline;Figs. 3 and 4 are similar sections showing also the fitting device;Figs. 5 and 6 are still similar sections showingIJUREAZΓOMPI discharge.of .the load ;Figs.- 7, 8 and 9 illustrate.the pusher panels used to remove the remaining load ; '-:. . Figs. 10 and 11 illustrate, schematically the 5 helicoidal rotor system ;Figs. 12, 13 and 14 show schematically respectively in cross section CFigs. 12 and 131 and. in general perspective (Fig.141 the operational platform conceived by the Author; Figs. 15 and 16 illustrate respectively a general 0 sectional view and a detail of the special, floating covering; Figs. 17, 18 and 19 represent..the platform arrangement and the engine room respectively in enlarged partial front view (Fig. 171, plan or top view (Fig. 18), and horizontal section (Fig. 191; 5 Figs. 20 to 24 represent the hollow floating tube of the pontoon shown in transverse section .(Figs.20 and 211 and illustrating how it rotates by means of the continuous ring shaped reservoirs (Figs. 22, 23 and.24) ;Figs. 25, 26, 27, 28,.29 and 30 llustrate the 0 system of winches, fenders and. braker. conceived by the Author.(el BEST MODE OF CARRYING OUT THE. INVENTIONI.' SELF-ROTATING PONTOON .WORKING BY LIQUID 5 - TRANSFERENCE FROM ONE RESERVOIR TO ANOTHERSuppose the floating tube described above as a vessel with its walls formed by watertight compartments, similarly to the ship side and with doublebottoms properly divided longitudinally, being able to stand a rotating 0 movement on its longitudinal axis, achieved by means of the liquid displacement in ballast tanks distributed in the periphery.For a better description of this rotation, the floating tube is initially represented by a transverse 5 section (Figs. 1 & 2) which shows two watertight ccπpartments forming juxtaposed and concentrical round shaped crowns whichIJURE OMP form its wall.Surely there are innumerable convenient, arrangements and positions to these tanks that would, reach,the same--. , result, but this one was chosen in order to simplify the 5 principle exposition.On that account., in the initial, stage of the exposition, the pontoon internal structure is neglected; it, as previously seen., can have many different arrangements in accordance with the desired utilization. 0 The conception is based on. the floating body properties, as here.described, to turn about, its longitudinal axis at any desired angle, by transferring, liquid existing in ballast, tanks of one side to the similar tanks situated on the opposite side, in a previously arranged sequence. 5 Considering, for instance, that initially the pontoon • shown in Fig. 1 is flooded only with the tanks located below the waterline (1-5)., and starts, to transfer the water (indicated in horizontal hatched, areal. sequentially from . tank Number 1 to Number 6, from Number .2 to number 7, from 0 Number 3. to Number 8 and so forth, we can. obtain a total rotation (36.0.91 of the floating tubel This property allows to conclude that in any pontoon, in which the transverse section has the shape shown in the 3rd item, it is possible to obtain the same effect (rotation) 5 through a simple water transference from one ballast tank to another, in a proper sequence, since these tanks have a convenient dimension in relation to the resultant formed by the structure weight moment, added to its cargo moment, related to the rotation center in each rotation instant. 0 2. SELF-ROTATING PONTOON WORKING BY LIQUID DISPIACE ENT INSIDE RING SHAPED RESERVOIRSSuppose a hollow floating tube represented by Figs. 20 to 24, taking into consideration only its double walls but not its internal structure arrangement.35 These walls are formed by continuous rings totally hollow (Flotation Tanks - 57} intercalated by rings that have only one division consisting of watertight bulkheads (591 which cannot be transposed by compressed air- (ballast tanks - 581.The ballast tanks are interconnected by means of 5 tubes, situated adjacently and in each side of the bulkhead, allowing free passage -ef air.They also have air outlets (611 provided of valves that can be remote controlled.Figures 20 and 21 represent the transverse section 10 of the floating tube cutting a ballast tank. (581.In both cases it is assumed that.inferior air outlet valves are closed., and the superior, ones open.If compressed air (stippled areal is injected inside the chamber (£21, the water level (horizontal lined 15 areal, existing inside its inferior section, will be driven to the opposite side (Fig. 211, causing a displacement of the center of gravity, arising for this reason a moment Ca pair of equal and opposite forces) able to surpass the inertia of the vessel and. produce its 20. rotation.At his stage, the moving of the bulkhead (591 and consequently of .the whole pontoon starts to occur in clockwise sense, driven by the compressed air (211. In fact, regarding to Fig. 20 : 25 - Point 0 is the vessel. Cor. tube! center of' gravity or the application point of the resultant Cformed by the combination of its own weight and load vectors1;- Force G is the resultant mentioned above ;- Point. 'C is the buoyancy quick works or volume 30 center, being the center of gravity of water volume displaced by the vessel, as well as the application point of force. ,E.' .;- Force. 'E' of buoyancy is the resultant of all vertical components of water pressure actuating on the35 vessel immersed surface.It is well known, as floating and equilibriumjυR OM requirements,..that vertical opposite.forces must.be equal and actuating at the same diametral, plane of the vessel, that is, at the vertical plane containing the vessel's -:. . longitudinal axle. The water interchanging inside the ballast tanks from one side to another (Fig.211, achieved by means of compressed air, dislocates momentarily the center of gravity of the vessel from.10.1 to. O. , creating a pair of equal and opposite forces CE.' -nd. 'G'l which provocates the apparatus rotation.This theoretical presentation is partly related to the above item and to the foregoing considerations.For this reason, it is possible to perform a rotation of the pontoon only by displacing, using compressed air. and the liquid inside its ballast tanks,or in other words, by displacing the.pontoon taking the liquid as reference.3.' PONTOON ROTATION BY MEANS OF EXTERNAL' POWER It is possible to produce rotation in the pontoon described in item No.3 without its inside liquid.To achieve this purpose, the Author, conceived a system of winches, fenders and brakes, as shown in Figs. 25, 26, 27, 28, 29 and 30..The winches C731, fenders C771 and pinion-brakes C74} are installed on trolleys which are - attached to the hull by means of a belt formed of tense wire ropes or chains C6 l . These ropes Cor chains}, are positioned in the correct, place with the aid of fixed sheaves C£7 & £8}, along its contour.The trolley platform has a circular shape to suit the pontoon external surface. The trolleys are sustained by sheaves C67 & 681 and connected to ropes Cor chains! forming the belt. They consist in a part of this belt, running on flanged wheels C£9 & 70L guided by rails (71 & 72}. Close to the trolleys (63} containing the winchesC73} , are placed the trolleys C641 equipped with the pinion-brake device (741, geared..by its turn to the αxwn- shaped rack C751. Like the.rails, the rack is arranged around the pontoon contour, as shown in the figures.The pinion movement on the rack is produced hydraulically, by motor, or by any other energy source, being stopped by means of any kind of remote controlled conventional brakes.On trolleys C651 similar to those of the winchesC631, and as those attached to the belt, are placed flotation tanks C79I, designed to keep. the belt steady during the pontoon rotation by means of its buoyancy. It must as well keep in proper position the accessories placed on. the belt, and absorb the stresses exerted on it, including those producing the pontoon rotation and braking.In like manner fenders C771 of any conventional type are placed in proper position on trolleys C78} attached to the belt.The pontoon outline size alterations due to the natural and momentary deformation.of its hull are not important in the present subject, but by precaution it is advisable to provide the belt ropes Cor chains1 with a.de{.t.aJ-_o elastic components Cspringsl aaeq&afcea. to the strains absorption. The utilization of the equipment disposed on the belt system here described, requires for its inspection and maintenance a hung ladder or similar, to be attached to the pontoon contouring the hull beside the belt, or fixed to it. 4. TRANSSHIPMENT OF DRY BULK CARGO THROUGH THEROTATING PONTOOAs previously seen, there are uncountable applications and structural arrangements which allow the invented craft self-rotation, provided that its basic characteristics are maintained, even for a specific utilization.Among these, was chosen for a better description itsOMP utilization. s dry bulk transshipment, pontoon. In this case, load can be transferred from the holds of any type of fluvial vessels to the storage, compartments internall - located in the proposed equipment, and, then, to an external hopper from which it can be lifted to an ocean - going ship deck, or conveyed to a terrestrial storehouse.As an example to this apparatus, it was conceived a pontoon transverse section shown in Figures 3-6, where are indicated : 1 to 12 - ballast tanks13 to 15 - flotation tanks1£ to 18 - watertight compartments which can be used as storage 19 <- canal 20 - vertically displaceable. watertight lifting device21 - vessel to.be unloaded22 - vessel hatch23 - mechanical conveyor 24 J 25 - retractible flood gates26. 27 - hinged, shutting panels28 - discharging chute29 - inspection gallery31 J 32 - Galleries of hydraulic and electric networks33 34 - Vertical hydraulical jack. 5.' TRANSSHIPMENT PONTOON OPERATION At the beginning of the operation only the ballast tanks 1, 3 and 5 and the lifting device which remains on the bottom of canal 19, are flooded.The vessel, towed by winches and with its hatches opened, enters this canal. The canal is equipped with photoelectric cells or guiding rollers, placed on its walls in order to avoid damages. Next, the vessel is perfectly aligned in relation to the pontoon longitudinal axis by means of verticallyIJUREATΓO PI displaceable horizontal hydraulic jacks, placed in proper positions along the canal walls. 'Thereupon, the water existing inside the lifting device C201 is transferred to tanks 2 & 4 through flexible hoses, and then the watertight lifting device C20} raises the vessel so that its deck leans against inspection gallery C29/301 inferior side, where the contact surfaces are revested with rubber to avoid water infiltration. The shape and size of this surface should be established according to the characteristics of the vesselCsl to be discharged.By means of vertically displaceable hydraulic jacks C33 & 341, placed on canal 19 walls, the vessel and eld the lifting device are -feold- together in this position against the pontoon structure.Panels 26 & 27 are placed in vertical position and fixed to galleries 31 & 32 walls.The pontoon rotation, is started through a progressive water transference from tanks of one border to the opposite, f as for example, in the following process : from 1 to 6 ;2 to 7; 3 to 8; 4 to 9; 5 to 10; and 6 to 11.Water transference from one tank or compartment to another can b achieved by means of compressed air, injected through a properly sized rigid pipeline, provided with Co ve iem+H -eonv niθifel placed remote controlled yalves and registers.As the pontoon rotation begins, the load starts flowing through- the vessel hatch to gallery 28 and then to the storage compartment 17 (Fig. 05}.Persisting the rotation, the pontoon will acccπplish a 1809 turn when tanks 7, 8, 9, 10 and 11 are flooded(Fig.6} .In this position, the pontoon is capsized and the load enters the storage compartment 17 due to gravity.Finishing this operation, the discharge gallery 28 is shut by positioning 26 and 27 panels against the mechanical conveyor compartment (23}, as shown in Fig.6.-BU EOMP Now the pontoon is ready to return to its original position, which is achieved through water transference inside ballast tanks. The water transference is now done -; in inverse sequential order i.e., progressively from 5 tanks 11 to £; 10 to 5; 9 to 4; 8 to 3; 7 to 2; and 6 to 1. Once the pontoon is in its normal upright position (Fig.4}_, the hydraulic jacks C33 &.341 are lowered to the bottom of canal 19.The flotation of vessel 21 is achieved simply by 10 transferring water rom tanks 2 & 4 to the lifting device C201, which will submerge to the canal bottom, releasing the vessel. After the removal of the horizontal adjusting jacks, the vessel can leave the apparatus.Since the pontoon is in its upright position, load 15 transference to outside can be achieved by means of any.conventional mechanical conveyance Cchain conveyor,endless screw, belt conveyor, etc.l or by their combination. The transportation system is installed inside a discharge chute C231, placed within the discharge gallery C281. In upright 20 position the chute is at the bottom,of storage compartment C171; thus., under the load to be conveyed outside.Concerning th cargo destination, there are two alternatives to accomplish the pontoon, operation : al the load must be.transferred right away out of 25. the pontoon, or temporarily kept in compartment17; - bl the load must be stored in one of the pontoon lateral storage compartments. Considering the former case, the retractible panels 30 C24.&.251 should have been closed, at the beginning of the operation, in order to hinder the.passage of load to compartments 16 and 18.In the latter case, one or both panels should have been kept open at the beginning of the operation, in order 35 to guide the load to its destinated compartment (16 or 181, when the pontoon returning to its original position is BUREAU0MP1 performed,If the load itiust.be stored, in compartment 16, the pontoon turning should be achieved, as stated above, but, if the load is to be stored in compartment.18, the pontoon 5 returning to its normal position must be carried out by continuating rotation in the same sense, accomplishing a 36}9 turn. The full turning of the pontoon is attained by progressively transferring water from tanks 7 to 12, 8 to 1, 9 to 2, 10 to 3, 11 to 4, 12 to 5 (Fig.61.10 When the load stored in lateral.compartments (16 or 181, has to be conveyed outside, it must, as a first step, to be transferred to compartment 17. This is done through the removal of the corresponding panel C24 o 251 , and through an appropriate rotation o the pontoon.15 The transshipment method described, in this text suits best to unpowered vessels with no masts Charges1, but it can also be employed to powered yessels since they are conveniently fitted.Even the barges should submit to a structure20 overhaul, in order to check its framing resistance to overturning efforts, and, if necessary, provide.the framing reinforcement.6. OPERATION WITHOUT LIFTING DEVICE .To raise and sustain within the pontoon. the vessel 25. to be unloaded Cor repaired} , hydraulic jacks can be used ■ as shown by No..33 & 34 (Fig.4}, since they are properly sized to bear the load. For this reason, it is dispensable the using of the lifting device shown as No. 20 in Figs.3 & 4. Evidently, the water transference from one tank to 30 another - in order to provocate rotation - must be altered.7. COMPLEMENTARY PROCEEDINGS AND ACCESSORY EQUIPMENT During the turning of the pontoon, the vessel is capsized and its load falls to the storage compartment 17 due to gravity. When it occurs, part of the load is retained 35 inside the vessel holds, because of the corners formed in the intersection of its sides and deck CFig.61. There are many ways to remove the remaining load, since the hold is adapted to the employment of appropriated mechanical equipment.A good suggestion to this matter would be the 5 installation of pusher panels (Figs. 7, 8 & 9 which show, enlarged, a corner situated inside the dashed circle}, juxtaposed to its walls in vertical position, when the vessel is floating (Fig.7}. After the capsizing, panels , can incline (Fig.8}, positioning their inferior edges 10 together with the hatch face (Fig.91, making all remaining load f ll inside the compartment 17.Panel movement can be achieved by hydraulic, mechanical, electromechanical or combined means, and its control should be preferentially remote, being capable to 15 put all panels into motion simultaneously.As accessory equipment, the Author conceived an helicoidal rotor system (35 & 36) indicated schematically in Figs. 10 & 11, the former showing a transverse section of the vessel with its upper part undermost, arid a section 2.0 of the mechanical conveyance 23 as well as a side view of the equipment, the latter showing an internal top view of the pontoon.The rotors are connected to a hinged arm system (37 & 38} , which by its turn is attached by means of rails 25 (39) to the bottom of the box containing the mechanical conveyance (23) , allowing the equipment a longitudinal displacement.The hinged arm system is hydraulically driven, enabling its positioning on the bottom of compartment 23 so 30 that allowing the vessel entrance inside the transshipment pontoon, when the equipment is not being used.The same procedure can be carried out with the rotors. The rotor blades can be swung one over the other, and all over the bottom of the compartment (hatched line - 35 Fig. 111.In order to place the tackles, reeving devices andIjUREAtTO PI fittings, anchoring and.raising implements C inches, anchors, anchor cables., rinding bitts, bitts, cleats,etc.1 and also the engine rooπi Cwith compressor, control board, etc.l the Author conceived the platform indicated in Figs. 5 12, 13 & 14.The first figure shows a front view of the pontoon, the second one a top view and the latter a parallel perspective view. . ,This platform is hold by columns .C401, which are 10 sustained by flotation tanks C41L properly sized to uphold not only its own and its charge weight but also thevertical component of the force exerted on the anchor cables.This platform surrounds the transshipment pontoon and is attached to it through joints of hollow piiis, placed 15 in both extremities along its longitudinal, geometric axis. Thus, the platform is divided in two equal parts that can support, one independently from the other, small movements produced by tensions on anchor, cables, waves or other accidental overloads. 20. Each of these parts is made up of rigid sections interconnected through, hinges to absorb .the tensions previously mentioned.On the transverse parts of the platform, situated at its ends C44} , are placed the anchor cable winches and other 25 . _ pieces of the anchoring and raising implements. For this reason, these parts are exposed to higher tensions.Moreover, they should support also the efforts produced, by the engine room C431 weight.The platform (45) side parts are structural '. components 30 designed to support principally the traction efforts resulting from tensions on the anchor cables, but they can also be used as passageways.They contain the cylindrical fenders. C 61 designed t absorb the pontoon side shocks against other, vessels or fixed 35 structures Cquay, pier, etc.).These fenders also funcion as friction rollers duringIJUO the pontoon rotation, when, the whole, platform stays in upright horizontal position.The rollers C471 have identical function,serving as platform support to the hull. The engine room covering C 8} has. its transverse section in shape of concentrical circumference arcs, juxtaposed to allow independent moyements-of platform parts located in each side of central joints C421.Since properly sized, the platform front parts, located at the pontoon entrance, can also function as covering, so that .hatches can.be. opened in. rainy days.However, to reach this specific purpose, the Author conceived a special floating covering CFigs. 15 & 161placed on a circular or polygonal structure supported by longitudinal flotation tanks, resting against the pontoon hull by means of spheric enders C51) .This structure is attached, to the pontoon through the same hollow pin Ctubel 42 and also by means of a spherical articulation C521 independent from that one which connects platform 44, so that these two structures operate independently, as shown in Figs. 17, 18. & .19 that represent, respectively, the platform C441 new arrangement and the engine room C531. enlarged partial front view, plan or top view and horizontal section. In these drawings (Figs. 17, 18 & 19} are represented the hinged articulation (541 from platfor to pontoon and the spherical one (52) from floating covering to pontoon, both through the pin tube C42) that is also used to lead canalizations and cables of general facilities (pneumatic, electric, hydraulic,etc. ) inside the pontoon.These canalizations and ducts, at least outside the pin-tube C42) , must be flexible enough to support, without rupture, the pontoon rotation.For this reason, this rotation should not surpass 3609 in the same turning sense.In this arrangement, the machine room C531 is hanged•fU EAlT OMPI by the roof frame C 9 through guy rods.The floating roof must have a fluctuating central part, covering the platform area C441, limited by panels (56}. These panels are inserted in the roof fluctuating part, in order to enable independent movement of roof and platform without rupture.To avoid abrupt rotations of the pontoon, it is possible to fit the fenders 4£ (Figs. 12 to 1£1 with a hydraulic brake system, which arrests motion by compressing the fenders against the hull. In that case, this extra- effort must be taken into consideration when dimensioning the flotation tanks 41 (Figs. 12 to 161.To achieve the external accessory equipment installation, and especially to provide the rotation braking, the belt device described in item No.6 can also be used.The solutions described in this text concerning equipment installation of the pontoon, if appropriate, can also be employed to any kind of floating dock.(f1 INDUSTRIAL APPLICABILITYIndustrial applicability of present invention is obvious.Any conventional method (manual, mechanical, hydraulic, etc.) can be used to control and set accessory ' equipment in motion. Automatic control from a pointoutside the system must be used when possible.The design, dimensions and details of necessary equipment or contrivance, employed to perform the general operation of the rotating pontoon, as well as its accessories, must be achieved considering its purpose and local depth of water, whichever rotation method chosen. It concerns the designer or the shipyard which will apply the invention.-βUROM < | - y -CLAIMS1 - Rotating Pontoon, capable of turning about its longitudinal axis, at any desirable angle from zero to 3609, with or without load, with or without necessity of external power, energy and material aid, and therefore propitiating its own maintenance of docking; capable to unload dry bulk vessels by gravity, to construct or repair vessels and store dry bulk cargo; with indistinct sides and deck, circular or polygonal shaped transverse section and, depending on its purpose, different arrangements being achieved inside its hollow interior; an auxiliary watertight floating device or hydraulic jacks being installed to provide the sustaining of vessels to be processed; characterized in that the rotation movement of pontoon can be achieved through the following means :Ca water transference between ballast tanks existing in the pontoon periphery, following a convenient sequencial order, operation.which is carried out bypurrping water or by compressed air (Figs. 3 to. £} ; (bl_ a simple displacement of the tank in relation to its liquid content, through compressed air action (Figs. 20 to 241 ; or(c) action of Pontoon external forces.2 - Rotating Pontoon according to claim 1, in which self-rotation is obtained through liquid transference between its reservoirs, characterized in that rotation movement by water transference is obtained through reservoirs arranged in horizontal series (Figs. 1 & 2)which outlines the pontoon ordenately. 3 - Rotating Pontoon according to claim 1, in which rotation is obtained through.fluid displacement in the interior of its reservoirs, characterized in that rotation movement is performed with the aid of continuous ring '-:. . shaped reservoirs with a single watertight bulkhead (Figs. 5 20 & 24) which are arranged one parallel to the other and interrelated, so that, under compressed air action on one surface of their liquid content and with the watertight bulkhead reaction, the Pontoon turns about its longitudinal, axis. 0 4 - Rotating Pontoon according to claim 1, in which rotation is obtained with external forces, characterized in that rotation movement.is produced by means of a rack and pinion gear system installed in the Pontoon external surface, supported by flotation tanks 5 through a belt and being driven by own engine.5 - Rotating Pontoon according to claim 1, comprising a transversely disposed belt, characterized for being connected to the external contour of the pontoon hull and capable of being held in a fixed position, while this 0 hull rotates, and of achieving its rotation movement as well as its braking, anchoring, towing and mooring, besides its protection against shocks, the said belt being constituted of two cables or chains attached to the pontoon hull by means of pulleys fixed on it, and containing 5'- trolleys where can be installed operational implements to anchor and raise the pontoon (winches, anchors, anchor cables, rinding bitts, bitts, cleats, etc.1, fenders, a special braking system to the rotation movement,flotation tanks to support the efforts exerted on it, or other fittings that should, if wished, not be affected by the rotation movement (Figs. 25 to 301.6 - Rotating Pontoon according to claim 5, comprising a rack and pinion gear system assembled on a trolley, which is attached to the belt,, characterized by providing the pontoon rotation and/or braking movement as indicated in claim 1 by means of a pinion on a fixed rackIJΌREOMPI • - A - surrounding the pontoon C74 and 75 of Figs. 27 to 301, the rotation being produced by an engine, and the braking through the pinion blocking by means of any usual types of remote controlled brakes, in such a manner that the 5 effort resulting from the pinion cogs on the rack is transmitted by the belt (No. 66 of Figs. 25 to 281 to the flotation tanks (No. 76 of Figs. 25 &.261 in which it is attached and- absorbed by them, so that the buoyancy of these properly sized flotation tanks can serve as support,10 or be opposed, to the pontoon, rotation movement.7 - Rotating Pontoon according to claim 1, comprising a longitudinally disposed platform,characterized for being maintained attached in normal upright position to the pontoon while it rotates, for propitiating the15 braking, anchoring, towing and mooring of the pontoon,the said platform being supported by flotation tanks connected . to the pontoon, unless in the positions corresponding to the ends of its longitudinal axis where it is attached to the pontoon by joints,, and being made up of articulated2Q sections with,.the purpose of. olding the engine room, operational implements Cwinches, anchors., anchor cables, rinding bitts, cleats, etc.} and its fenders, that can also be used as brakes of the pontoon rotation movement CFigs. 12, 13 & 141.25 8 - Rotating Pontoon according to claim 1, comprising an accessory garage, characterized for being maintained. attached to the pontoon. in normal upright position, while it rotates, the garage being made up of a transversal structure with polygonal shape, circumference30 arc shape, or by their combination, leaning against the flotation tanks and having any conyentional type of roof, and being attached to the pontoon through a spherical joint situated in the extremity of its rotation (or longitudinal! axis. (Fig. 15 to 19) .35 9 - Rotating Pontoon according to claim l,for transshipment of dry bulk cargo, characterized by its possibility of unloading, by gravity, dry bulk vessels byUREAlT0MP1 - A - means of a simple pontoon rotation, causing the load to fall through, the vessel hatches .( holly protected against water infiltration!, to the storage compartment, the load being transferred afterwards to storehouses or storage bins, which transfer operation is accomplished by the rotating pontoon, since it has in its interior void spaces to be occupied by the vessel Cor vessels! to be processed; by a discharge hopper, connected to one or more storage compartments, and by any conventional dry bulk horizontal conveyance Cchain conveyor, endless screw, belt conveyor, etc. - Figs. 3 to 61.10 - Rotating Pontoon according to claim 9, comprising remaining load pushing panels - Chatch feeders! to be adapted inside the holds of vessels designed to operate in the rotating pontoon, characterized by a system made up of several panels installed inside the vessel hold, placed against, its sides and close to the inner side of deck, which panels, after the vessel capsizing, can be gradually inclined, pushing the remaining load through the hatches and can be set in motion by means of. any of the following means : hydraulic;, mechanical; electric-mechanical; and, if possible, remote controlled.11 - Rotating Pontoon according to claim 9, comprising a helicoidal hatch feeder, system to be installed inside the pontoon hopper or discharge chute, 'cha acterized by its possibility of removing the load fraction which remains next to the hold corners, after the vessel capsizing, which system is made up of helicoidal rotors attached to hinged arms that can be conjugated in order to place the rotors at any convenient work position and when the system ceases operation, both rotors can be put together on a single plane.'fUREOMPI | KRAMER DA LUZ O | KRAMER DA LUZ O |
WO-1979000133-A1 | 1,979,000,133 | WO | A1 | EN | 19,790,322 | 1,979 | 20,090,507 | new | A61K39 | null | A01K61, A61K39 | A61K 39/00D2 | IMPROVEMENTS IN OR RELATING TO FISH FARMING | Fish are treated to produce an auto-immune response therein which impairs the development and/or maintenance of a normal gonad system in the fish. Such a response may be produced by the administration of antibodies to gonad tissue or of antigenic material derived from such tissue. | IMPROVEMENTS IN OR RELATING TO FISH FARMING This invention relates to methods for modifying the sexual development of fish.Fish farming, particularly of salmonids, has developed rapidly throughout the world over the last ten years. However, one of the major unsolved problems associated therewith is that of the control of gonad maturation. Thus the growth rate of many fish falls off when sexual maturity is achieved and disease, particularly skin disease, becomes more prevalent. Moreover, it is preferred that male salmonids, for example, mature at the salmon (2 sea winter plus) stage of development when they are of a good size, but a proportion mature naturally as parr or as grilse. This can lead to increases in mortality rate among the fish and also to an unpredictable supply of fish for marketing. Furthermore, the diversion of food energy into gonad production is a financial waste and high food costs are among the limiting factors in salmonid farming. Total elimination of gonad in stock being reared for the table is therefore a desirable objective.Several methods have been suggested in the literature for the modification of gonad development in fish including surgical castration, hormone treatment and daylength control but, despite the attraction in developing a truly satisfactory method, all of these methods which have previously been considered tend to suffer from one or more disadvantages such as practicability on a large scale, expense etc. It is anOMPI ,< W1PO ,Λ< object of the present invention, therefore, to provide an improved method for the modification of gonad development in fish in order to produce fish which are not sexually mature. Accordingly the present invention comprises treating a fish to produce an auto-immune response therein which impairs the development and/or maintenance of a normal gonad system in the fish.It will be appreciated that the immune system of a fish differs considerably from that of a mammal, for example it contains only one major immunoglobulin rather than five.Therefore, although auto-immune responses are well known in mammals, it was previously by no means clear that it would even be possible to produce an auto-immune response in fish and, as far as we are aware, this is the first instance of any such auto-immune response being produced.The present invention is of particular application to teleosts (Teleostii) including Isospondyli and Ostariophysi, for example to salmoinids (or fish' of the family Salmonidae), especially to fish of the sub family Salmonini containing the genera Salmo, Oncorhynchus, etc. Thus, it is of considerable interest in the treatment of salmon, for example both Atlantic and Pacific salmon, and trout, for example rainbow trout. The invention is however also of interest in relation to eels and especially to carp including Tilapia. Indeed, it will' be appreciated that the invention is applicable to a very wide variety of fish, both marine and fresh water, BUREOMPI although its benefits will be particularly marked with certain types as described above.The method may be applied to the fish at various stages in their growth, for example in the case of salmon and related salmonids as alevin, parr, smolt, grilse or even older fish.Clearly, however, it is preferable to treat the fish at as early a stage as is conveniently possible in their sexual maturation, although it has been found that the method of the invention may be used not only to prevent the development of gonad tissue but also lead to the retrogression thereof. Although the invention is' of particular application to male fish in view of the greater problems posed therewith by early maturation, it is also applicable to female fish.The production of the desired auto-immune response in the fish is effected by inducing in the fish the presence of antibodies against gonad tissue. This may be done by administering such antibodies to the fish directly or, more preferably, by administering to the fish antigenic material which induces the formati-on of such antibodies. Such antigenic material may be derived from sperm or particularly testis gonad tissue in the case of males and ovarian tissue in the case of females, varying degrees of purification being possible including the use of simple extracts of gonad tissue and purified antigens. When treating a population of salmon or like fish of mixed sex, it may be convenient in view of the difficulties associated with the sexing of salmon either to treat each fish with a mixture of-BUREAUOMPl antibodies or of antigenic material deriving from both male and female fish or, if it is not desired to do this, to treat each fish with male derived antibodies or antigenic material in view of the lesser interest in the application of the method to female fish.It will be appreciated that the use of purified, or at least partially purified, antigens may be desirable to remove side effects arising from other antigens present as impurities in a crude preparation which may lead to an auto-immune response in other parts of the body. It is believed that the antigens of interest in the present context are surface antigens, particularly those of a water soluble nature, and these may be extracted by a variety of techniques including the use of both ionic and non-ionic detergents, hypo- and hyper-osmotic shock treatment and sonication of membrane fractions.The antigenic material may, if desired, be administered . together with an adjuvant, for example complete Freund's adjuvant (CFA), or rather more preferably in view of the intended use of the fish as food, with an adjuvant material ' which, in contrast to .complete Freund's adjuvant contains a killed or inactivated fish pathogen or pathogens. The latter alternative has the advantage that by using as the adjuvant a vaccine such as vibrio or furunculosis vaccine the additional effect is produced of providing protection against the infection in question. A further form of adjuvant material which may be considered is one of the algal extracts with potent adjuvant properties such as carrageenin, for example the kapa, lambda or particularly the iota form. Such extracts are usually water-soluble and are of particular value, therefore, for use in the hyper-osmotic treatment described hereinafter. It may also be desirable to enhance the effect of the antigenic material by using material from one species for administration to another, for example rainbow trout material in salmon, and vice versa and/or by the use of hooster doses of antigen (or antibodies). Further modifications include the solubilisation of antigens by various techniques, particularly for use in the hyperosmotic treatment described hereinafter, and the attachment of antigens to larger molecules to form immune complexes, for example to immunoglobulins such as rabbit immunoglobulin.Various routes may be used for administration of the antigenic material (or antibodies where applicable) including oral and parenteral, for example intraperitoneal and intra¬ muscular, routes. If desired, an initial administration by such a parenteral route of the antigenic material together with an adjuvant such as complete Freund's adjuvant may be employed, followed by a further administration of the antigen only by a similar route. In compositionsfor such a mode of administration the antibodies or antigenic material are made up in a physiologically acceptable carrier or diluent. This is usually of liquid form, being for example, isotonic saline or phosphate buffered saline. One alternative, very convenient, method of administration involves immersion of the fish in an aqueous hyperosmotic medium which contains, or is followed by immersion in an aqueous medium containing ,the antigenic material. It is believedthat this method involves take up of the antigens primarily through the lateral line system but also secondarily through the gills. It will be appreciated that this method is generally more convenient than other routes of administration but that it generally requires a somewhat purer and more fully water soluble antigenic material. Various compounds may be used to produce the hyperosmotic solution including inorganic salts, for example sodium bicarbonate and chlorides such as magnesium, calcium, potassium and especially sodium chloride, sugars such as sucrose and dextrose, urea etc. The amount of the compound is selected to give an appropriate osmolarity to the solution, for example in the range from about 400 to 1650 milliosmoles or possibly even higher, for example up to about 2500 or 3500 milliosmoles or even more, although values of about 1650 milliosmoles are preferred. Thus 10 per cent w/v urea and 5*23 per cent w/v sodium chloride each give solutions of 1650 milliosmoles. A •two stage procedure in which the fish is immersed first in the hyperosmotic solution and then in the solution containing the antigenic material has certain advantages such as avoidance of any interaction of the compound producing the appropriate hyperosmotic effect with the antigenic material.The application of the present method to inhibit, or desirably to substantially eliminate, the gonad system of fish can have certain other advantages in addition to those indicated above. Thus, it will be appreciated that the present invention produces the very great advantage that once the need to harvest fish imposed by their achievement of sexual maturity has been removed it is possible to regulate their growth to a suitable size for harvesting merely through control of feeding so that farmed fish may be harvested at a time when wild fish are not available. Moreover, the present need to feed expensive pigmented food to all of a group of salmon in sea water in case of early maturity can be avoided, such food being fed only immediately prior to the selected time of marketing. A further advantage may be illustrated in relation to the present considerable interest concerning the introduction of Pacific salmon into the United Kingdom for farming purposes. This has led to considerable controversy regarding the possible competition which could arise with the native Atlantic salmon if these fish were to escape. The ability to gterilise the Pacific salmon at an early age would avoid any long term problem arising in the event of such escape.The invention is illustrated by the following Examples. EXAMPLE 1: Treatment of Salmon (Small group)A group of salmon parr of age 1 year plus and of mean length 10cm was used, it being known that some of the males would in the normal course of events mature in a period of about 2 months. One of these maturing males was killed and the testes extracted. A whole testis was ground up and pushed through a fine mesh sieve to separate the cells. The testisjύREA∑OMPI W1 > was then washed three times in phosphate buffered saline- (the first washing involving passage through a sieve of a mesh which accepts single cells in order to separate connective tissue etc., which is retained by the sieve), centrifuging after each washing to remove serum and other water soluble and suspendable solids, then decanting and resuspending for the next wash. The resulting pellet was suspended in phosphate buffered saline (3 ml) and mixed with complete Fr-βund''s adjuvant (4ml) using an ultrasonic probe. The resulting emulsion (0.2ml) was then injected intraperitoneally into salmon parr on 13th October 1976. A follow-up injection of sperm in phosphate . buffered saline (0.2 ml) was given four weeks later on 10th November 1976. A second set of salmon parr were kept in similar tanks as controls and received no treatment.The control group of salmon developed gonads and smolted in the normal way. Of the five treated fish, three survived until May 1977 when all had become smolts. These fish were killed and examined, material being fixed in 10% formal saline, embedded in hard paraffin wax, cut at f and stained in H and E, Mallory's trichrome and Una Pappenheim. The results obtained were as follows. Fish 1This fish was male and both superficial examination and subsequent histology suggested that the fish had been maturing at the time of injection. The testes showed signs of degeneration and appeared to have adhered to the body wall.0MP Histόlogical examination showed that massive degeneration of the testes had in fact taken place, together with oedoema and proliferation of fibrous tissue, neighbouring muscle tissue not being damaged. Staining with Una Pappenheim showed many pyroninophyllic cells; these being plasma cells associated with antibody production in immune reactions. ■ No germ cells could be seen on the section as would be expected in normal male stnolts which had been mature in the preceding Autumn. (The state of degeneration seen in the testis was similar to that seen in the pancreas in conditions such as acute infectious pancreatic necrosis where the pancreas degenerates and does not recover:) . Fish 2When this fish was dissected it appeared that the gonads were those of a male smolt which had not matured previously, i.e. they comprised two long thin strands lying in the dorsal part of the body cavity. However, histological examination showed that the testes had in fact responded to the injection. Compared with a normal smolt testis there was an increase in fibrous tissue and in tfrepresence of plasma antibody-producing cell, and a lack of germ cells. Histological examination of spleen, liver and kidney from this fish showed: no abnormalities. Fish 3 Gross and histological examination showed this fish to be a female fish which was developing in the manner of an untreated smolt.-BUREAUOMPI It will be seen from the results obtained upon examination: of the three ish that degeneration of both immature and. matures male gonad was brought about by injection of a gonad/adjuvant preparation whilst no other organs were apparently effected, and smoltification and growth were also apparently unaffected. At the same time, development of the female gonad was not affected. EXAMPLE 2: Treatment of Salmon (Large group)A group of 650 salmon parr of an age 1 freshwater plus 1 sea water and of a size range 30 - 50 cm. length was used, the fish being both male and female. The fish were divided randomly into seven sub-groups which were treated as follows on l4th March 1978, the treatments being administered after benzocaine anaethesia by intreperitoneal injection with a 23 gauge hypodermic needle, and subsequently'marked by freeze branding for subsequent identification of the differently treated groups (saline used was phosphate buffered):1) no treatment (50 fish)2) 0.2ml of 0.85% w/v saline (50 fish) 3) 0.2ml of an emulsion o 0.85% w/v 'saline -in CFA (l/2 v/v)4) 0.2ml of 0.85% w/v saline containing 20mg/ml iota carrageenan (X52 Augygel; batch No. 3557) ( 0 fish)5) • 0.2ml ofO'.85%w/v salinecontaining 10% v/v gonad extract prepared from tissue as described in Example 1 but using 50% male:5P% female gonad tissue, the latter (ovaries) being extracted in'the same way as male testis * ' (150 fish) BURE 0MPI 6) 0.2ml of an emulsion consisting of gonad extract prepared as for (5), 0.85% w/v saline and CFA (IO/25/65 v/v/v) (150 fish)7) 0.2ml of 0.85% w/v saline containing 10% v/v gonad extract prepared as for (5) and 20mg/ml of iota carrageenan (X52Augygel; Batch No. 3557) (10 ish).On 12th April 1978 all fish were identified according to their previous treatment by means of their marking and were weighed and measured. The first hundred fish of each of the groups 3 -, 6 and 7 were treated with 0.2ml of 0.85% w/v saline containing 10% v/v of gonad extract prepared as for (5) and were then marked to identify them.On 9th May 1978, all fish were identified, weighed and measured as before and the first fifty of the doubly treated -fish of groups 5, 6 and 7 were treated with 0.2ml of 0.85% w/v saline containing 10% v/v of gonad extract prepared as for (5), then marked to identify them.On 26th July 1978, a small number of fish in each of the sub-groups were measured and weighed, then killed and examined.The results obtained on 12th April and 9th May were used to calculate a mean length and mean weight for each sub-group and from these figures to calculate a condition factor (weight/ cube of length). In the case of the measurements made on 9th May a figure for daily growth in terms of both weight and length was calculated. The'data thus obtained are shown in Tables 1 and 2. It will be seen that the treatments did-BU EAUOMPI . WIPO Λ> not produce any statistically significant adverse effect on the growth of the fish during the two months following treatment. (Slight variation in the number of fish recovered from expected figures, especially in sub-groups 1, 2 and 6, arose from minor errors in counting of the original numbers in individual groups and/or in subsequent identification of fish according to individual groups.)On superficial visual examination of the dissected fish which were killed on 26th July it was found that atrophy of the gonads had occurred in all male fish of sections (b) and (c) of the sixth (CFA) sub-group. Similar atrophy was not identifiable in the absence of histological examination, which still remains to be carried out, in female fish of the sixth group or in fish of the fifth and seventh groups. Processing of the results' on the length and weight of the fish to provide data such as is presented for the 12th April and 9th May results similarly remains to be carried out. However, an initial examination suggests that there was again no significant difference in this- respect between the various groups. It will be appreciated that the advantages in relation to growth dependent upon failure to achieve sexual maturity would only be expected to emerge at a later stage of development of the whole group of salmon. Table 1; Data for 12th April 1978Group Number Mean Mean Condition (Treatment) Recovered Length Weight Factor cm. gm• gm. cmUntreated 45 40.74 810.67 1.20Saline 52 39-78 763-84 1.21Saline + CFA 50 40.38 801.00 1.22Saline + 50 40.33 791.60 1.21 carrageenanSaline + total 148 40.56 799.73 1.20 gonad extract(a) 1 - 100 39-99 750.4 1.17 total 148(b) 101-148 41.75 902.5 1.24Saline + total 165 3 .-67' 748.85 1.20 gonad extract+ CFA a) 1 - 100 39.90 758.20 1.19 b) 101-165 39.31 734.46 1.21Saline + gonads . , _,■ , ,„ _-_. extrac.t. +a total 146 40.69 815.07 1.21 carrageenan a) 1 - 100 40.43 78 . 6 1.19 b) 101-146 42.28 882.95 1.21 Table 2; Data for 9th May 1978Group Number Mean Mean Condition Daily(Treatment) Recovered Length Weight Factor GGrroowwtthh cm. gm. gm.cm RRaattee % _ Day Length WeightUntreated 54 42.71 956.85 1.23 0.18 0.6Saline 49 41.55 872.24 1.22 0.16 0.49Saline + CFA 49 42.08 914.90 1.23 0.15 0.49Saline + 47 42.06 915-53 1.23 0.16 0.54 carrageenanSaline + total 148 42.34 932.7 1.23 0.16 0.57 gonad extract a) 1 - 50 42.07 893.80 1.20 r b) I - 98 41.88 883.26 1.20 0.17 0.6l c) 98-148 43.23 1029•6 1.27Saline + total 159 41.44 872.57 1.23 0.16 0.57 gonad extract+ CFA a) 1 - 50 - 41.87 904.40 1.23 b) 1 - 91 4l.6θ 889.56 1.24 0.15 0.59 c) 92 -159 41.22 849.85 1.21Saline + total 146 42.38 933.84 1.23 0.15 0.51 gonad extract + carrageenan a) 1 - 50 42.08 915.00 1.23 b) 1 - 97 42.07 903.40 1.21 0.15 0.52 c) 98 - 146 43.OO 994.08 1.25 EXAMPLE 3; Treatment of Rainbow TroutA mixed sex group of rainbow trout of age 1 year plus was used. The fish were divided randomly into six sub-groups. One of these sub-groups received no treatment and was used as a control. The other sub-groups were treated on 1st March 1978 by intra-peritoneal (i.p.) injection with a gonad extract prepared from male rainbow trout in a substantially similar manner to that described for salmon in Example 1, no follow-up injection with sperm..being used however. The first of these sub-groups received a mixture of 0.05 tal of the testis suspension together with 0*1 ml of complete Freund's adjuvant and 0.08 ml of an extra cellular product (E.C.P.) isolated from cultures of Aeromonas salmonicida whilst the second received a mixture which was similar as regards two components but which instead of the E.C.P. contained 0.1 ml of isotonic10 phosphate buffered saline containing 10 washed and formalin killed Aeromonas salmonicida cells.The remaining three sub-groups were treated on the same date with the same gonad extract by a hyperosmotic infiltration (h.i.) technique, the fish being immersed for 2 minutes in a bath containing 8% w/v of NaCl and then for 2 minutes in a second bath containing the gonad extract. The different treatments accorded to each sub-group involved the use of a second bath of 500 ml of water containing 4 ml of the testis extract in each case, together with 2 ml E.C.P. for the - 16 -11 first group, 20 ml. E.C.P. for the second group, and 10 washed and killed Aeromonas salmonicida cells for the third group.Eleven weeks after treatment the fish were killed on17th May 1978 and their serum tested for sperm agglutinating factor against sperm obtained by stripping a ripe male rainbow trout and washing the isperm three times in isotonic phosphate buffered saline. The test employs the usual slide agglutination technique with doubling dilutions to determine the greatest level of dilution at which agglutination is still present. Table 3 shows the results obtained for the various sub-groups of fish in the slide agglutination test (zero indicating complete lack of agglutination at the concentrated level) and it will be seen that the fish of all six treated sub-groups showed sperm agglutinating factor in their serum. Table 3» Sperm Agglutinating Factor in Rainbow Trout SerumSub-Group Number in Group Agglutination LevelsUnvaccinated 2 0 5 01 (i.p.) 1 1:42 (i.p.) 2 ' 1:4 ; 1:41 (h.i.) 2 1:4 ; 02 (h.i.) . . 2 1:8 ; 1:23 (h.i.) 2 1:4 ; 1:4<_ | CLAIMS1. A method of treating fish which comprises inducing in fish the presence of antibodies against gonad tissue thereby producing an auto-immune response therein which impairs the development and/or maintenance of a normal gonad system in the fish.2. A method according to Claim 1, wherein the fish is of the teleost group.3. A method according to Claim 2, wherein the fish is a salmonid.4. A method according to Claim 2, wherein the fish is a salmon or trout.5. A method according to any of Claims 1 to 4, wherein the fish is a male.6. A method according to any of the preceding claims, wherein the antibodies are induced in the fish by the administration of antigenic material derived from fish gonad tissue.7. A method according to Claim 6, wherein the antigenic material is administered parenterally by injection.8. A method according to Claim 6, wherein the antigenic material is administered through immersion in a medium containing the antigenic material, simultaneously or subsequently to treatment with a hyperosmotic medium.9. A method according to' any of Claims 6, 7 and 8, wherein the effect of the antigenic material is enhanced by the use of an adjuvant.-BU AUOMPI „ IPO Λ 10. A method according to Claim 9ι wherein the adjuvant comprises one or more killed or inactivated fish pathogens.11. A method according to Claim 9, wherein the adjuvant is a Freund's adjuvant.12. A method according to any of Claims 1 to 5» wherein the antibodies are induced in the fish by the direct administration thereof.13. A method according to any of Claims 6 to 12, wherein the effect of the antigenic material or the antibodies is enhanced by the use of a booster treatment.-14. A method according to Claim 1 substantially as described. in Example 1.15- A method according to Claim: 1 substantially as described in Example 2.16. A physiologically acceptable composition for the treatment of fish to impair the development and/or maintenance of a normal gonad system in the fish which comprises .as an active ingredient thereof antigenic material derived from fish gonad tissue. 17. A composition according to Claim 15 which comprises an adjuvant.18. A composition according to Claim 17, wherein the adjuvant is a Freund's adjuvant.19. A composition according to Claim 16, wherein the adjuvant comprises one or more killed or inactivated fish pathogens. 20. A physiologically acceptable composition for the treatment of fish to impair the development and/or maintenance of a normal gonad system in the fish which comprises as an active ingredient thereof antibodies against gonad tissue.21. A composition according to any of Claims 16 to 20, wherein the fish is of the teleost group.22. A composition according to Claim 21, wherein the fish is a.salmonid.23« A composition according to Claim 21,, wherein the fish is a salmon or trout.24. A composition according to any of Claims l6 to 23 in unit dosage form.25. composition according to Claim 16 substantially as described in Example 1.26. A composition according to Claim 16 substantially as described in Example 2.27. A method according to Claim 1 which employs a composition according to any of Claims 16 to 24.28. Fish whenever treated according to the method of any of Claims 1 to 15 and 27.-BUR A ΓOMPI | ELLIS A; HOLLIDAY F; LAIRD L; NAT RES DEV; WILSON A; NATIONAL RES DEV CORP | ELLIS A; HOLLIDAY F; LAIRD L; WILSON A |
WO-1979000140-A1 | 1,979,000,140 | WO | A1 | XX | 19,790,322 | 1,979 | 20,090,507 | new | H01L31 | null | H01L23, H01L31 | H01L 23/38, H01L 31/052, H01L 31/052B, H01L 31/058 | SOLAR PANEL UNIT | The elements of the solar panel are arranged generally in parallel planes that, starting from the top, include a transparent sheet (5), a plurality of converging lenses (6), a plurality of solar cells (7) arranged in electrical series respectively aligned with the converging lenses (6), an electrically insulating support plate (8) that together with the sides (4) of the solar unit and the top sheet (5) form a vacuum chamber for the lenses (6) and solar cells (7) to reduce heat transfer by convection and conduction upwardly from the solar cells (7), a thermopile (11), a heat sink plate (15) receiving heat from the thermopile (11), heat transfer fins (16) receiving heat from the heat sink plate (15), a serpentine conduit (17) in heat exchange with the heat fins (16), thermal insulation (23), and a bottom plate (3) that is connected to the side walls (4). Two-side walls (4, 4') contain mating couplings (23, 24, 21) for each of the conduit (17), thermopile (11), and photoelectric cells (7) so that two adjacent panels may be interconnected with such couplings (23, 24, 21) to provide fluid connection and electrical connection between the adjacent panels. | SOLAR PANEL UNITTechnical Field 5 The present invention relates to a solar panel unit that 'may collect solar energy and convert it into a more reusable energy form, such as electrical energy or a heated liquid.Due to the increase in cost and depletion of fossil fuels, other energy sources are becoming increasingly important, 10 and the use of solar energy has great potential. One of the main problems with the solar panels employed today is that their efficiency is relatively low so that a large surface area is required to produce a usable quantity of energy.Background Art15 In the prior art, U.S. Patent No. 3,976,508 provides heat exchange between solar cells and a coolant, U.S. Patent No. 3,988,166 provides heat exchange between a fluid and photovoltaic cells, and U.S. Patent No. 2,989,575 discloses a solar battery employing a specific heat transfer mounting2.0 for the cells.Disclosure of InventionIt is an object of the present invention to produce a more efficient solar panel, so that thereby for a given quantity of desired usable energy, the area of solar panel25 required will be at a minimum.Lenses are provided to concentrate the solar energy to photoelectric cells for the production of electricity, and the heat that is necessarily produced is prevented from leaving the system, to a large extent, by an evacuated30 chamber while at the same time reflected radiation is limit¬ ed due to the greenhouse effect of the top transparent sheet that assists in the formation of the evacuated chamber. The heat thus produced is conducted downwardly to a thermopile where it is partially converted to electricity, and further conducted downwardly to where it is used to finally heat water that may be used in the hot water system of a residen or for space heating purposes at a remote location. Therma insulation is provided below the water pipes. 5 The panels are provided with electrical and fluid couplings so that adjacent panels may be connected togetherBrief Description of DrawingsFurther objects, features and advantages of the present invention are shown in the accompanying drawing, which show 10 a preferred embodiment that is at the present time the best known mode of construction.FIGURE 1 is a partial cross sectional elevational view of two adjacent solar panels constructed according to the present invention, and as taken along line I-I of Figure 2; 15..andFIGURE 2 is a partial cross sectional view taken along line II-II of Figure 1.'Best Mode for Carrying Out the InventionFigures 1 and 2 disclose portions of two adjacent and20 intercoupled solar panel units, which are of identical construction. For example, the portion shown of the left hand unit could be joined to the right side of the portion of the right hand unit to represent a single complete unit, and because in this manner a single unit is completely show25 effectively, portions of each unit have been removed to simplify the disclosure. In plan view, each unit'would preferably be of rectangular configuration, so that a plurality of such units could be interconnected across a roof or other support to form a composite solar collecting30 panel of a desired cross sectional area.Since the solar panel unit 1 and. solar panel unit 2 are of identical construction, the same numerals will be used for the two panels, with primes being used for the numerals of panel two, and the description of one will35 suffice for the other. The solar panel unit 1 has an upwardly opening enclosure formed by a bottom wall 3 and side walls 4 extending around the entire periphery of the bottom wall 3. The top of the enclosure is closed by means of a self supporting sheet of -material transparent to solar radiant energy, for example glass 5. Immediately beneath and parallel to the glass 5, there is a sheet of material transparent to solar radiant energy and providing a plurality of circular, as seen in plan view, lenses 6. The lenses 6 may be of the same construction as those shown in United States Patent 3,929,121 issued December 30, 1975. Immediately beneath the lenses 6, there are provided a pluarality of electrically serially interconnected photoelectric cells 7, which may be of identical construction to and interconnected in the manner as the photoelectric cells of United States Patent 4,002,031 issued January 11, 1977. Beneath the cell 7, there is provided a support plate 8, which is constructed of electri¬ cally insulated material that has good thermal conductivity. The plate 8 and top 5 are sealingly connected around their • entire peripheries to the side walls 4, so as to form with the side walls 4 a hermetically sealed enclosure that is evacuated so as to greatly decrease heat transfer by conduc¬ tivity or convection from the photoelectric cells 7 to the top plate 5. As shown, the unit would be arranged so that preferably • the solar radiant energy as indicated by arrows 9 will pass through the transparent plate 5 in a direction perpendicular to the plane of the plate 5 and be concentrated by means of the lenses 6 so as to converge in concentrated beams 10 onto the individual photoelectric cells 7, with a number of lenses preferably being equal to the number of vertically aligned photoelectric cells 7. In this manner, the majority of the solar radiation will strike the photoelectric cells 7 so as to produce electricity in each of the cells, with the cells being serially connected so as to produce a useful voltage between the positive and negative electrical terminals of the serially connected photoelectric cells 7 of each unit.OMPI Any radiation that docs not strike the photoelectric cells 7 will strike the support plate 8, which is preferably black to absorb the radiation and convert it into heat. Since the enclosure formed, by the plates 5, 8 and side walls 4 is evacuated, the heat generated within the photoelectric cells 7 and the plate 8 will be conducted downwardly.Beneath the support plate 8, there is a thermopile 11 that is preferably of the same construction as shown in United States Patent 2,984,696, issued May 16, 1961. The to conductors 12 of the thermopile are connected to the bottom conductors 13 by means of thermocouples 14 in a known manner so that the thermopile will produce a substantial useful voltage at its positive and negative output terminals accord ing to the number of thermocouples connected in series, whil transferring heat from the support plate 8 downwardly to the conductors 12 and from there to the conductors 13. The conductors 13 are in direct engagement with a heat sink plat 15 that forms the cold junction of the thermopile. Preferab the heat sink plate 15 is hermetically sealed around its entire periphery to the s'ide 'walls 4, so that the area con¬ taining the thermopile may be evacuated. If desired, the support plate 8 need not be hermetically sealed to the side walls 4 if the heat sink plate 15 is sealed.Any heat that has not been converted into electrical energy with the thermopile is received by the heat sink plat15 and conducted downwardly by means of heat exchange fins16 that are preferably bonded to the lower surface of the heat sink plate 15 on their upper end and extend downwardly so as to substantially surround the parallel portions of a serpentine pipe 17, with the fin 16 and pipe 17 being joi ed by solder or the like to improve the heat transfer. As shown, U-shaped bends 18 of the pipe 17 joined the ends of the parallel straight sections of the pipe 17 to form one singly serpentine conduit for each solar panel unit. One end of the conduit is provided with a right angle joint 19, having its portion 20 permanently secured to the one end of the conduit and its portion 21 providing a releasable condu coupling. The portion 20 may be soldered to its end of the pipe 17, whereas the portion 21 may include an aperature of the same diameter as the pipe 17 provided with a 0-sealing ring to form a fluid tight seal with any pipe 17 inserted •5 within the end 21. The opposite end of the conduit is provided with a right angle bend 22 to provide a coupling portion extending beyond the side wall of its unit, so as to be telescopically received in sealing engagement within the coupling 19. In this manner, two adjacent solar panel 0 units may be fluid interconnected so that their serpentine pipes will be serially connected.In the event that the solar panel unit is to be exposed to the environment, and the environment is to upon occasion drop below freezing at time when solar energy is not avail- 5 able, for example at night, it is desirable to provide thermal insulation 23 below the pipes 17, which insulation will also insure that the heat reaching the pipe 17 will not travel any further downwardly to any substantial extent. As mentioned above, the serial array of photoelectric 0 . cell 7 will have, for each solar panel unit, a positive electrical output terminal and a negative electrical output terminal. Preferably, one of such terminals will be provided with a releasable coupling part so as to extend through the side wall having the fluid coupling 19, whereas the other 5 part of a mating releasable electrical coupling -will be electrically connected to the other terminal so as to extend through the side wall having the releasable fluid coupling 22, with such electrical coupling parts being in correspond¬ ing locations so that they will interconnect when the fluid 0 couplings 19, 22 interconnect. Such electrical couplings may be conventional bayonet connections or the like. In the same manner, the output terminals of the thermopiles are connected between adjacent units with releasable electri¬ cal coupling 24. Thus, the positive output terminal of the 5 serially arranged photoelectric cells 7 of unit 1 may be electrically connected through releasable electrical coupling 23 to the negative output terminal of the photoelectric cellsOMPI - > -7' of the unit 2, one of the positive and negative electric terminals of the thermopile 11 may be connected through releasable electrical coupling 24 to the other of the posit and negative terminals of the thermopile 11' of unit 2, and the downstream end of pipe 17 may be connected through releasable fluid coupling 19, 22 to the upstream end of pipe 17 of unit 2, all of which may be accompanied by merel aligning the units 1 and 2 and horizontally pushing the uni together to telescopically engage their couplings. When an entire composite of panels has been assembled for the desir area, the exposed couplings at the outer sides of the compo ite may be interconnected by fluid conduits and .electrical conductors respectively either in series or parallel as desired. Water or some other liquid may be passed through the serially connected pipe 17 to be heated, and this hot water may be stored to be used as needed for the heating of enclo sures through hot water radiators or for supplying hot wate for domestic use such as showers.. The use of hot water for heating purposes and domestic consumption is shown in Paten 2,946,945 issued July 26, 1960. Also, the hot water produc may be used in heat exchange with a fluid to be evaporated for the running of a turbine, as disclosed in United States Patent 4,002,031 -issued January 11, 1977. The electrical energy produced by the photoelectric cel and the thermopile may be stored in a battery for later usa as disclosed in United States Patent 2,946,945 issued July 1960. Also, the electricity produced by the thermopile and photoelectric cells may be employed as the electrical energ source for the system disclosed in United States Patent3,459,953 issued August 5, 1969 for the production of hydro gen and oxygen through electrolysis, which gases are stored and later withdrawn to be burned to produce products of combustion for driving a gas turbine that in turn drives an electrical generator providing electrical energy for usage as desired, with the products of combustion being condensed^♦ O after passing through the turbine to provide pure water that may either be a source of pure water for any desired purpose or a source of water for the electrolysis unit. The disclosure of the above mentioned patents is • incorporated herein in its entirety for the purposes men¬ tioned to produce the entire solar energy conversion system of the present invention.In operation the solar panel unit of the present inven¬ tion is designed to extract approximately 767, of the solar energy striking it, and to convert the energy into other forms of more usable energy. The extraction-conversion process is accomplished in three separate stages, with each stage employing a different type of process. The first stage involves the use of photoelectric conversion through the employment of solar batteries, photovoltaic cells, or photoelectric cells, which all broadly are referred to in the present invention as photoelectric cells meaning trans¬ ducers that will receive direct solar radiant energy and converted directly into electrical energy. The second stage involves the use of thermoelectric conversion whereby heat differentials are converted into electric power, and in the present invention the term thermopile is used to broadly indicate such a device that directly converts heat into electricity. The third stage acts as a heat sink for the second stage as the cold terminal, and in so doing heats cold water which is then stored in hot water facili¬ ties. The hot water can later be used for the heating of a home or for other hot water requirements of a dwelling. Although solar energy varies greatly depending upon a number of conditions, a valid assumed rate of 1 Langley radiation per minute for many locations in the United States appears to be a reasonable working estimate. Thus, a square meter receives approximately 10 kcal per minute of solar radiation. Over the span of one average bright dayIJOREΛTΓOMPI (8 hours radiation) a home roof of approximately 1,000 square feet will receive approximately 500,000kcal of energ This is roughly equivalent to 13 or 14 gallons of gasoline. With an extraction-conversion process having 76% efficienty, the average home would on a bright day be able to produce t equivalent of 9.88 gallons of gasoline. Of course, if more energy were required this would simply entail enlarging the unit.The efficiency of the present invention is in part accomplished by the top wall 5 that will admit most of the radiant energy and prevent reradiation of the wave length through a greenhouse effect. That is, the material of the cover or top wall 5 will transmit the long wave lengths of light allowing them to enter the unit, but will not transmi the short wave lengths of reflected or reradiated energy, thereby trapping the energy within the unit. Some of the radiant energy will be directly converted to electricity by the photoelectric cell 7, whereas the rest of the energy trapped within the unit will be converted1 to heat. Because of the insulation 23, which may be rigid foam plastic, for example polystyrene, and the evacuation of the chamber between the sheets 5 and 8 at least, or between the sheets 5 and 15, there will be very little loss of heat through conduction and covection. The solar battery units will be preferably of semi- conductive material with a conversion efficiency of 10%. The thermopile will use some of the heat to produce electri city and conduct the remainder of the heat downwardly throu the unit. The thermopile is constructed, in a known manner, of a plurality of thermocouples having two dissimilar metal or semiconductors joined so as to produce a hot junction (above) and a cold junction (below) , which will produce electricity and when the thermocouples are arranged in series, the electricity will be of a substantial usable voltage. The conversion efficiency of such a thermopile is approximately 10%,. The heat sink, that is necessary for a thermopile, is provided by the metal plate 15 and the heat withdrawn by the water passing through the pipe 17, with the usable heat in the water raising the efficiency, of the entire unit up to the above mentioned approximately 767». The fluid and electrical connections between some of . the units may also be in parallel instead of in series, as desired, particularly along the outer edges of the assembled units; some of the connections internally of a unit may be in parallel. For optimum light collection, the side walls 4, 4' may also be transparent, and the side walls 4, 4' may be formed in one piece with the top 5 to be closed by a separate bottom 3.While a preferred embodiment has been shown in detail for the purposes of illustrating the best mode known at the present time, further embodiments, variations and modifications are contemplated according to the broader aspects of the present invention, all is determined by the spirit and scope of the following claims. | Clni s1.. A solar energy conversion system, comprising: a top fluid impervious sheet that freely passes solar radiant : energy; a plurality of photoelectric cell means arranged in a plane spaced below and parallel to said top sheet for receiving the solar radiant energy and directly converting a portion into electricity and converting substantially the remainder into heat; means electrically connecting said photoelectric cell means in a power producing circuit; a thermopile means below said photo- electric cell means for receiving the heat, converting a portion of the heat into electrical energy, and transmitting the remainder of the heat downwardly; sup¬ port means between said array of photoelectric cell means and said thermopile means for electrically • insulating said thermopile means from said photoelectric cell means, for conducting heat downwardly, and converting any radiant energy direc¬ tly received thereon into heat; a planar heat sink means immediately below said thermopile means for receiving and transmitting downwardly the heat trans¬ mitted by said thermopile means; and liquid conduit means beneath and in heat exchange relationship with ■ said heat sink means.2. The solar energy conversion system of claim 1, including side walls around the entire periphery of said top sheet, photoelectric cell means, support means, thermopile meansn heat sink means and conduit means to form an enclosed unit; one of said side walls having a first releasable electrical coupling part electrically connected to one of the electrical terminals of said thermopile means, a second releasable electric coupling part electrically connected to one of the electrical terminals of said photoelectric cell means, and a first conduit coupling part fluid connected to one end of said conduit means; another of said side walls having a third releasable electrical coupling part of a mating configuration with said first releasable electrical coupling part being electrically connected to the other of the electrical ' terminals of said thermopile means, and being at a loca¬ tion to register with the first electrical coupling part of a horizontally aligned and immediately adjacent identical unit; said another side wall having a fourth electrical coupling part of a mating configuration with said second releasable electrical coupling part, being electrically connected to the other of the electrical terminals of said series connected photoelectric cell means, and being at a location to register with the second releasable electrical coupling part of the hori- zontally aligned and immediately adjacent identical unit; said another side wall -further having second conduit coupling part of complimentary mating shape to said first conduit coupling part, fluid connected to the opposite end of said conduit means, and being at a location so as to matingly register with the first conduit coupling part of the horizontally aligned immed¬ iately adjacent identical unit. 3. The solar energy conversion system of claim 2, including a planar array of converging lenses spaced below and parallel to said top sheet for receiving the solar radiant energy passing through said top sheet and pro¬ ducing a plurality of radiant energy concentrations respectively on said plurality of photoelectric cell means.4. The solar energy conversion system of claim 2, comprising a layer of thermal insulation immediately beneath said conduit means. 5. The solar energy conversion system of claim 2, including means including said top sheet for forming a herme- tically sealed vacuum enclosure having therein at least said photoelectric cell means for reducing heat transferIJUREΛTΓOMPI by convection and conduction upwardly away from said photoelectric cells and said support means.6. The solar energy conversion system of claim 2, includ¬ ing said conduit means comprising a metallic pipe ' arranged in a serpentine path within a single plane parallel to and closely spaced to said heat sink means; and a plurality of heat transfer fins bonded to the lower surface of said heat sink means and extending downwardly to partially surround at least a major portion of said pipe.7. The solar energy conversion system of claim 1, including a planar array of converging .lenses-spaced below and parallel to said top sheet for receiving the solar radiant energy passing through said top sheet and producing a plurality of radiant energy concentrations respectively on said plurality of photoelectric cell means.8.. The solar energy conversion system of claim 1, including a layer of thermal insulation immediately beneath said conduit means.9. The solar energy conversion system of claim 1, including means including said top sheet for forming a hermetically sealed vacuum enclosure having therein at least said photoelectric cell means for reducing heat transfer by convection and conduction upwardly away from said photoelectric cells and said support means.10. The solar energy conversion system of claim 1, including said conduit means comprising a metallic pipe arranged in a serpentine path within a single plane parallel to and closely spaced to said heat sink means; and a plurality of heat transfer fins bonded to the lower surface of said heat sink means and extending downwardly to partially surround at least a major portion of^-said pipe | KRAVITZ J | KRAVITZ J |
WO-1979000144-A1 | 1,979,000,144 | WO | A1 | EN | 19,790,322 | 1,979 | 20,090,507 | new | H01R35 | H01R39 | H01R39 | H01R 39/00 | ROTARY COUPLING | A rotary coupling for transmitting electric current and fluid between a rotating (2) and a stationary (1) body. The electric current is transmitted by way of slip rings (15) provided on an insulating sleeve (8). In axial grooves (12) of the sleeve elongated electric connection strips (17) are provided. Electrically conducting slip rings (15) and insulating spacer rings (16) are thread alternately over the sleeve. Each slip ring is electrically and mechanically connected with a separate strip (17) and each strip is electrically connected with conductors (18) arranged within the stationary body. Current conductors (4) are fixed to the rotating body. Each current conductor is in sliding electrical contact with a corresponding slip ring. The fluid is transmitted with a nipple (21) connected to a fluid hose (20). The nipple presents a throat (24) around which a sleeve (25) connected with the rotary body is tight and rotatingly mounted. | Technical fieldThis invention refers to a rotary coupling for transmitting electric current and fluid, especially compressed air.Background ArtDevices of this kind are known, for example from the British patent specifications 1 202 648, 1 349 850, 1 440 866, the German patent specification 848 378, the Swedish patent spe¬ cifications 90 160, 128 275, 175 979 and from the Swiss pa¬ tent specification 397 810.The disadvantage of these prior devices is that they cannot be adapted in a simple way for use together with an arbi¬ trary number of electric conductors.Disclosure of InventionThe present invention aims at removing this disadvantage and refers to a rotary coupling which is primarily suitable to be used as a rotatable control handle-for working machines where the number of control lines may vary from one type of machines to another. The control conductors are electrically connected to switches, potentiometers etc. for controlling the working movements of the machine.Brief Description of DrawingsFig. 1 shows the rotary coupling according to the invention in ft tiir nπ-noctionnl viow (partially in a front view) and Pig. 2 shows a sectional view along the line II-II in Fig. 1_ Best mode of carrying out the InventionIn Fig. 1 the rotary coupling according to the invention is' shown to include an axle 1 which, for example, may be stati nary mounted in a movable part of a working tool. The worki tool may be a small electric hoisting apparatus, for exampl The movable part may be a lifting beam, for example, which movable in elevation and which can be turned in the horizon plane. At the end of the lifting beam the rotary coupling a a pneumatically controlled gripping tool which grips the wo piece to be hoisted are in turn provided. The movements of the hoistin apparatus are controlled by electric motors which are gover by means of controls, such as potentiometers and switches, which have a fixed mounting on a housing 2 which surronds t axle and which is rotatably mounted on the axle by means of roller or ball bearings 3. The advantage of this arrangemen is that the operator can walk round the work piece without releasing the grip on the housing 2 on which the controls a provided. These controls are electrically connected by con¬ ductors, not shown, with current conductors 4, 5, 6 which conventionally include, for example, spring loaded carbons arranged on a holder 7 which is rigidly connected with the housing wall. The end of the axle has a sleeve 8 of insulti material mounted thereon. The sleeve has a through bore 9 coaxial with a through bore 10 in the axle. The sleeve has portion 11 of reduced diameter. This portion has a number o axially extending grooves made therein of which only groove 12 is shown in the drawing. The depth of the groove is less than .the wall thickness of the portion 11. The grooves exte from the end face 13 of the sleeve 8 up towards the axle. A number of through openings 14 connect the bottom surface of the grooves 12 with the bore 9. Alternate electrically con¬ ducting slip rings 15 and spacer rings 16 are threaded on t the portion 11 of the sleeve. Each slip ring has an insulat • electrically conducting connection strip 17 fixed thereto b soldering which is thus received in a respective groove 12.The free end of each connection strip terminates substantia ly opposite the respective opening 14 and there is electric ly connected with its own insulated electric conductor 18. The conductors 18 may be assembled into a cable 19 (Fig. 2) which passes through the bores 9, 10. With the arrangement described it is seen that the housing may be turned round the axle any number of revolutions while maintaining electric contact be¬ tween the current conductors 4, 5, 6 and the respective line 18.Passing through the bores 9, 10 there is a hose 20 for trans¬ mitting a fluid, in the present example compressed air. The hose is threaded on to a nipple 21 and is held in place on the nipple by a clip 22. The nipple has a flange 23 which contacts the end face 13 of the sleeve 8. The nipple is fixed to the sleeve by screws not shown which pass through the flange 23 into threaded bores (not shown) in those portions of the end face of the sleeve which are left between the grooves 12. The • nipple has a throat 24 round which a sleeve 25 having an in¬ terior groove 26 is rotatable and tightly arranged by means of 0-rings 27. The nipple has a central axial bore 28 which terminates in a through radial opening 29 which communicates with the interior groove 26. A tube 30 or corresponding means connects the sleeve 25 with a fluid connection appliance (not shown) fixed to the housing to which appliance a fluid powe¬ red tool, in the present case a compressed-air powered gripp¬ ing tool, may be coupled. It is seen that the above sleeve- -nipple arrangement allows rotation of the housing any number of revolutions while maintaining fluid transmission between the hose 20 and the fluid connection appliance.A sleeve 31 with an axial slot 32 relieves the cable 19 from tensile stresses. The sleeve has axial through bores the dia- meters of which substantially correspond to the diameters of the cable and hose, respectively. A radial groove 35 is made in the outer surface of the sleeve 31. A stop screw 36 is thre'aded into the wall of the axie and serves to squeeze the sleeve 31 against hose and cable as well as to keep the sleeve 31 in position in the upper portion of the bore 9. Many varying modifications and variations are allowed within the scope of the basic idea of the invention. For example, more or fewer slip rings (and with these a larger or lesser number of grooves 12) may be provided. It is important for the invention, however, that a suitable number of slip rings and spacer rings can be thread on to the portion 11 of the sleeve, before they are thereupon fixed to the sleeve by mea of a washer 37 or corresponding means, whereupon the conduc¬ tors 18 are connected electrically, for example soldered at the end of the respective connection strip.Industrial ApplicabilityThe invention may preferably be used as a control handle of a hoisting apparatus. The invention is not restricted to th field of use but may be equally well used in connection wit working tools wherein electrical current and fluid are to b transmitted in a rotary coupling. | Claims1. A rotary coupling for transmitting electric current and fluid, including an axle (1) having an axial bore (10) , a • housing (2) rotatably mounted on the axle and current con- ductors (4, 5, 6) fixed to the wall of the housing and ro- tatable about the axle, characterized by an insulating sleeve(8) fixed at one and of the axle and having a ghrough bore(9) and a portion (11) of reduced diameter having provided thereon a number of axial grooves (12) each adapted to re- ceive an electric connection strip (17) , electrically con¬ ducting slip rings (15) and electrically insulating spacer rings (16) arranged alternately on said portion (11) of re¬ duced diameter so that each slip ring is in electric contact with its own current conductor, while each connection strip (17) at one end is electrically connected to its associated slip ring and at its other end is electrically connected to an associated electric conductor (18) which passes through said bores (10, 9) of the axle and sleeve and through radial through openings (14) made in connection with said other end of the respective current conductor, and a connection nipple (21) for a hose (20) with fluid and fixed to the end face of the sleeve, said nipple having a throat (24) about which a sleeve (25) connected with the housing is tightly and rotatab¬ ly mounted.2. A rotary coupling according to claim 1, characterized by the fact that the number of grooves (12) in the sleeve corre¬ sponds to the number of slip rings (15) .3. A rotary coupling according to claim 2, characterized1 by the fact that the axial grooves begin in said end face (13) of the sleeve (8) and that said radial through openings (14) all are in substantially the same plane in close connection to said end face.4. A rotary coupling, characterized by the fact that the cur-- U EA T OMPI,Λ wipo -* rent conductors . (4, 5, 6) are mounted on a holder (7) wmich is fixed to the housing.5. A rotary coupling, characterized by an axially slot-bed sleeve (25) arranged in theupper portion of the axle fear re lieving the electric conductors and the hose.6. A rotary coupling according to claim 5, characterizecl by a stop screw (36) provided in the axle for squeezing the sl ted sleeve (25) .7. A rotary coupling according to claim 6, characterize-d by the fact that the housing (2) is rotatably mounted on the a (1) by means of ball or roller bearings (3) .-WR OM | ANDERSSON K; ANDERSSON VERNER ING BYRA; ANDERSSON INGENJOERSFIRMA | ANDERSSON K |
WO-1979000147-A1 | 1,979,000,147 | WO | A1 | XX | 19,790,322 | 1,979 | 20,090,507 | new | A41D1 | null | A41D1 | A41D 1/22 | MULTI-FUNCTION AND MULTI-STYLE GARMENT AND METHOD OF MAKING THE SAME | Garments, particularly women's garments and method for making them. Generally, women's garments are made so that they may be worn in only one configuration or style. In accordance with this invention, there is provided a multi-purpose or multi-functional and multi-style garment (10) which has a generally tubular structure or configuration, having in the upper section thereof at least two integral tie sections (32) and (34), the locus of the profiles of the tie sections being of generally triangular configuration and the length of the tie sections being greater than the radius of the tubular structure, whereby the garment is adapted to multiple functions and styles and modular coordination with accessories. A garment of this invention can be made from a tubular blank, a planar blank folded upon itself, or from a flat unfolded piece of textile material. | MULTI-FUNCTION AND MDLTI-STYLEGARMENT AND METHOD OFMAKING THE SAMEThis invention relates to garments and a method for making the same. More particularly, the invention relates to a multi-functional and multi-style women's garment that is capable of being fashioned in a plurality of ways by the wearer thereof, and to a method for making the same.OMPI Background of the InventionMulti-purpose, multi-functional and multi-style garments are known. For example, U.S. Patent 3,473,167 deals with a multiple use dress. An adjustable skirt which can be worn in a variety of styles is disclosed in U.S. Patent 2,487,580. Other multi-style and/or multi- use garments are disclosed, for example, in U.S. Patents 3,143,740; 2,721,327; 2,668,293; 2,593,059; 2,575,791, 2,429,188 and 1,834,331, as well as in other publications.* However, while the known multi-purpose, multi-functional and multi-style garments are generally acceptable and accomplish desirabl end results, the more simple forms are relatively limited with respect to the variation of styles that can be achieved with them. There exists, therefore, a need for a multi-purpose, or multi-functional and multi-style garment which is relatively simple in construction and which at the same time is capable of being styled in a wide variety of ways by the wearer thereof, while, on the other hand, being easy to fabricate, easy to drape and readily lending itself to modular coordination with accessories. The present invention fulfills. this need. Brief Statement of the InventionIn accordance with the invention there is pro¬ vided a garment which comprises a generally tubular structure having in the upper section thereof at least two integral tie sections, the locus of the profiles of the tie sections being of generally triangular configuration and the length of the tie sections being greater than the radius of the tubular structure, whereby the garment is adapted to multiple functions and styles and modular coordination with accessories. The length of the tie sections is defined by the highest peak and lowest valley or depression of the profiles of the tie sections. In addition, the garment may include a lower longitudinal slit generally aligned with the contiguous borders of the tie sections. Expressed in other terms, a multi¬ purpose or multi-functional and multi-style garment according to the invention comprises a generally tubular- shaped configuration when disposed on the body of an individual wearer and which forms a generally rectangular configuration when disposed symmetrically in a plane, the generally rectangular configuration having opposite long sides, an upper edge and a lower edge, the upper ' edge lying at least partially within the area of a first right triangle, the base of which spans the long sides of the garment and the altitude of which is collinear with one of the long sides. In some embodiments, the upper edge may also lie partially within a second right triangle having a common hypotenuse with the first triangle and being congruent with it. The DrawingsServing to illustrate exemplary embodiments of the present invention, are the drawings which are to be taken in conjunction with the following description of the invention, and wherein: Fig. 1 is a rear elevational view partially in section of a first embodiment of the invention;Fig. 2 is a side elevation view of the garment of Fig. 1;Fig. 3 is an isometric, elevation view of a tubular shaped textile blank from which the garment of Fig. 1 may be made;Fig. 4 is an elevation view of the blank of Fig.Fig. 5 is an elevation view of the blank of Fig. with a portion of the blank removed to form an inclined upper edge; Fig. 6 is an isometric, elevational view of the garment of Fig. 1 formed by adding longitudinal slots to the modified blank of Fig. 5; Fig. 7 is an isometric, elevational view of a second embodiment having an upper edge of greater inclin¬ ation than the garment illustrated in Figs. 1 and 6; Fig. 8 is a view of the garment of Fig. 7 with the tube opened and disposed in a plane;Fig. 9 is an isometric, elevational view of a third embodiment of the invention having an upper edge of greater slope than the corresponding edge of the first embodiment; Fig. 10 is a view of the garment of Fig. 9 with the tube opened and disposed in a plane;Fig. 11 is an isometric, elevational view of a fourth embodiment of the invention which includes openings located near the greatest depth of the curve;Fig. 12 is a view of the garment of Fig. 11 with the tube opened and disposed in a plane;Fig. 13 is an elevation view of a fifth embodi¬ ment of the invention with modifications in the upper edge and longitudinal slot;Fig. 14 is a plan view of the garment of Fig. 13 with the tube opened and disposed in a plane;Fig. 15 is an isometric, elevational view of still another embodiment of the invention;Fig. 16 is an elevation view of the garment ofFig. 15; andFig. 17 is an isometric elevational view of a garment employing the first embodiment of this invention disposed on the body of an individual wearer. BURE UOMPI Description of the Preferred EmbodimentsThe embodiment of Fig. 1 comprises a multi¬ purpose, or multi-functional and multi-style garment 10 of generally tubular configuration. The tube is provided with an opening or slit 12 extending longitudinally downward from an upper edge 14 of the tube, the edge being in the shape of a generally circular curved arc that slopes gradually deeper into the wall of the tube reach¬ ing its maximum depth at a point directly opposite the opening 12, thus resulting in the formation of integral tie sections 32 and 34. Disposed in the wall of the tube and emanating from the opposite and, there is a second opening or slit 16. As can be seen by disposition of the garment of Fig. 1 in a symmetrical relationship on a flat surface, that is in a plane, as shown in Fig. 2, it forms a generally rectangular configuration of double thickness 18, provided with opposite long sides 20 and 22, a lower edge 24 and a concavely curved upper edge 26 of the pair of triangles 28 and 30 shown in broken lines. As can be seen in Fig. 2, the base of triangle 28 ortho¬ gonally spans the long sides 20 and 22, while the altitude of triangle 28 is colliner with the upper segment of long side 22.It is to be understood that while upper edge 26 is illustrated and described as having the shape of a generally concave, arcuate curve, other embodiments may include convex lines and rectilinear shapes. For example, the profile of upper edge 26 may be a substantially straight inclined line or a series of line segments of different slopes.In addition, the lengths of slits 12 and 16 can each be varied individually and with respect to each other. The depth of the upper edge 26 is also variable as shown more particularly by comparing Figs. 2 or 5 with the pro¬ files in Figs. 7, 9 and 11.The garment of Figs. 7 and 8 is similar to the one of Figs. 1, 2 and 6 except that the depth of inclined upper edge 26 is greater than the corresponding edge of the first embodiment, and is furthermore approximately equal to the length of slot 12.. The configuration of Figs. 9 and 10 bears this same relation, having an upper edge 26 of even greater depth, and an upper slot of substantially equal length. A lower slot, however, is omitted. Also the radii of the segments forming the edge 26 cover a greater range in this example, increasing markedly from the base to the tip of the tie sections 32 and 34.In the example of Figs. 11 and 12, the planar form is again polygonal (four or more included angles) . However, the variation in radii is not as pronounced as in the case of Figs. 9 and 10. Also, although the depth of upper edge 26 is relatively large, it is less than the length of slot 12. Additionally, this configuration includes not only slot 16, but openings 36 and 38 as well for receiving the ends of ties 32 and 34 as described more fully below.It may be seen from the foregoing that tie sections 32 and 34 can vary in length, dependent upon the length of opening or slit 12 and the depth of the curve, the locus of the profiles of the tie sections however being of generally triangular configuration and the length being greater than the radius of the garment's cylindrical configuration. By way of example, a tubular garment of one size in accordance with the first embodiment of this invention has a circumference of 50 inches and a slit or opening 12 which is 27 inches long to define two integral tie sections. In other examples the circumfer¬ ence of the tubular configuration may be increased to 56 or 60 inches, respectively, and the slit or opening 12 increased in both cases to 40 inches in length. It should be noted that the length of slit or opening 12 can be equa to or greater than the depth of the upper edge 26, as illustrated in the embodiments of Figs. 1 through 12.A further embodiment of a garment in accordance with this invention is illustrated in Figs. 13 and 14. J-t' has a configuration somewhat similar to that shown in Fig. 1 except that the opening 26 corresponding to slit 12 of Fig. 1 is in the shape of a second generally concave, arcuate cut 40.As a consequence, the upper concavely curved edge 26 extends from long side 20 to a point lying on the base line of the second congruent right triangle ^30. Also edge 26 has a depth greater than that of slσt 40 with both serving to define integral tie sections 42 and 4By way of example, the depth of opening 40 in an exemplary garment of the type illustrated in Figs. 13 and 14 is abou 36 inches; this dimension is less than the depth of the edge 14, being about 5/6 thereof. The circum ference of the garment is about 60 inches.Turning now to Figs. 15 and 16, the embodiment illustrated therein comprises a garment 46 of generally tubular configuration which when disposed symmetrically in a plane forms the generally rectangular profile shown in Fig. 16. The profile is defined by a lower edge 48, sides 50 and 52, and an upper edge in the form of two triangular shaped tie sections 62 and 66 (which are superimposed on respective identical tie sections 60 and 64; see Fig. 15) . The contiguous edges 58 of the tie sections are of a V configuration and have a depth substantially the same as that of the edges 54 and 56. . As with the other embodiments, the dimensions of the multi-style dress of Figs. 15 and 16 will depend upon garment size and on preferred style. In an illustra¬ tive example, the dress has a circumference of 56 inches with the tie lengths all being approximately 14.5 inches long.In a garment according to this invention, the total overall length of the periphery of the upper edge is generally greater than at least twice the circumference of the tubular structure and may be as much as three times or more greater than the circumference.It is also to be understood that the overall length of the garment is variable to make it adaptable for wear as a short street dress or a long evening dress, ' as well as a blouse or tunic-length garment. The tie length however will not undergo a comparable variation.Other variations may be achieved by flaring or partially tapering the otherwise tubular configuration and by employing in the lower periphery, multiple slots similar to slot 16 of Fig. 1.The garments of this invention can be made in conformity with the standard sizes employed in the apparel field. Thus, the length and circumference of the basic tubular construction and tie length can be varied as required to provide the usual range of standard sizes normally employed in the manufacturing and retailing of garments (e.g. small , medium , large and extra large ).In use, the various embodiments may be draped in many ways to achieve various functional and esthetic effects, The tie sections 32 and 34 may be disposed around the neck of the wearer and tied together at the back of the neck. In another configuration, they may be crossed in the front and tied behind the neck. In still another style, the ties can be crossed in the front, passed over the shoulders, crossed again in the back, brought around the- waist of the wearer and tied in the front.For still another style, the tie sections may encircle the upper torso of the wearer under the arms. Alternatively, one tie section can be passed diagonally across the upper torso and over the shoulders whereas the other tie section can be crossed over the first tie section and deployed under the opposite arm with the two tie ends then attached at the back. By placing the ties at the front, side or back of the wearer above the bust line, or at the waist line, other styles can be achieved. A still different effect may be achieved, for example, by bringing the ties around to the back where they are crossed and then brought up over each shoulder and tied in the front.The foregoing are not exhaustive but merely illustrative of the many configurations that can be achieved starting with the simple garment configurations of the invention. Even sleeve effects can be achieved by suitable disposition of the tie elements.With respect to the garment of Figs. 15, 16/ it may be fashioned in similar manner. It can also be changed from a jumper tied on either shoulder to an evening dress by tying the two back tie sections around the front of the torso and tying the two front tie sections around the back of the neck. By appropriate disposition of each pair of ties, strapless, one-shoulder, cowl and skirt styles can be achieved which are comparable to those attainable with two tie systems.A still greater variety of styles and functions may be achieved by the addition of tie securing means such as are provided by the openings 36 and 38 in the embodiments of Figs. 11 through 14. These openings are adapted to receive the ends of the tie elements when they have been deployed on the wearer in the desired configuration. For example, when the tie elements are deployed diagonally or vertically over the shoulders and down the back, they can then be threaded through the respective openings 36 and 38 and secured thereto, or passed thereafter around the body of the wearer and tied in the front.An illustration of one of the foregoing styles is provided by Fig. 17. The dress 68 illustrated therein comprises the tubular shaped configuration of Fig. 1 which encircles the torso, with the integral tie sections or elements 32 and 34 crossed at the front, disposed around the neck of the wearer, and tied at the back of • the neck as shown at 70.While the preferred embodiments are of generally tubular configuration when worn, they may be sold in an opened non-tubular or flat form with the edges thereof provided with suitable closures such as zippers, Velcrol, hooks or the like either in manufacture or by an ultimate user so that the preferred tubular construction of the garment can simply be accomplished by closing the same around the body of an individual wearer. Moreover, the garment of this invention can also be used in conjunction with capes, scarves, hoods, ponchos, sashes, belts and other apparel items such as clips, pins, brooches and the like to provide further variations of styling, thus being adapted to modular coordination with accessories.The preferred garments can be made from any of . a wide variety of suitable textile fabrics which may be knit or woven structures and comprised of either natural or synthetic materials such as, for example, wool, cotton, silk, nylon, polyesters, acrylics and the like including blends of such materials and also reinforced paper products suitable for textile use. Furthermore, the weight per given unit or density of fabric, such as weight per- yard, for example, may vary widely and is not critical. On the other hand, it is to be understood that the more dense or heavy fabric does not lend itself as well to as wide a variety of styles due to the limited manipulative qualities thereof. As a practical matter, preferred textile fabrics which can be used to fabricate the garments of this connec¬ tion are cotton, wool and synthetic jerseys, such as nylon, polyester, any of the synthetic silk jerseys and cotton and wool knit jerseys and blends of such materials and like like. MethodThe structural simplicity of the preferred garments make them amenable to various methods of manufac¬ ture. Speaking generally, the process comprises forming a generally tubular configuration from a blank or workpiece of textile material, shaping the upper edge of the tubular configuration to form an inclined segment which slopes into the wall of the tubular configuration to a point of desired depth, forming an opening or slit in the wall of the tubular configuration at a point diametrically opposite the point of maximum depth of the inclined segment thus forming at least two integral tie sections; at least one other longi¬ tudinal opening or slit may be provided in the periphery of the lower edge, in alignment with the upper opening or slit.The tubular configuration can be made on known circular or flat knitting and weaving machines properly programmed to provide the required edge profiles and open¬ ings or slits.The method may also be practiced by commencing with a flat blank or workpiece of textile material which has a generally rectangular configuration, symmetrically folding the blank laterally in half, removing a slanted portion of the textile from the folded blank to form the upper edge, securing or seaming the contiguous long sides (which were brought into contact with each other) partially along their length while leaving an unjoined upper section, the borders of which define contiguous edges of the tie elements. By omitting to seam the lower section of the contacting long edges, the slot 16 may be formed.The ultimate profile of the tie elements will depend upon the shape of the section removed in forming the upper edge. For example, removing a portion of the textile material from the blank may provide a structure such as shown in Fig. 5. Removal of different shaped upper edge portions will produce the garments of Figs. 6 , 7, 9, 11, 13 and 15.As previously mentioned, a garment in accordance with this invention can also be made from a textile blank which is itself tubular shaped and in this variation the tubular textile blank is disposed in a plane thereby forming a generally rectangular configuration and the subsequent manipulative steps are repeated except that since the blank is a closed tube it is not necessary to form the slots by partially closing the tube. On the contrary the slots, whether they be substantially straight slots or curved cut outs, are formed simply by removing additional textile material from the blank in a shape necessary to form the desired openings, or by slitting.Finally it is to be understood that it is also within the contemplation of this invention to make a garment in accordance therewith from a flat generally rectangular blank of textile material by removing from the blank a portion of the textile material to form a generally arcuate edge section extending from the long side of the blank towards the midpoint of the short side thereof , removing a like (e.g. mirror image) portion of the material to form a second generally arcuate edge section extending from the opposite long side of the blank towards the same midpoint of the short side, thereby forming an upper edge in the blank. Subsequently, an opening is formed in the blank commencing at the point of intersection of the arcuat edges and extending longitudinally towards the bottom edge of the blank, thus forming at least two integral tie sectio If desired, a second opening, e.g. 16, can likewise be formed in the blank extending from the bottom edge toward the upper edge. Maniuplating a blank in such a fashion results in configurations shown generally in Figs. 8, 10, and'12.In order to achieve the variations shown in Figs. 13 and 14 from such a flat blank one simply removes textile material from the blank to form the illustrated upper edge profile and thus provide two integral tie sections.Similarly, to achieve the variation or embodi- ments of Figs. 15 and 16, one carries out the same opera¬ tions except that the removed material is configured in conformity with the illustrated upper edge profile to thus provide four integral tie sections. No matter which variation is so formed from a flat rectangular blank, it may, when the operations set forth above are completed, be conveniently closed along the remaining portions of the long sides to form a tubular configuration or structure in use. In other words, the blank cut as indicated can be sold in flat form and closed by an ultimate wearer, or it may be closed in manufacture by joining edges 20 or 22 and sold in the tubular form to an ultimate wearer. Furthermore, it is to be understood that in the final tubular structure so formed, the locus of the profiles of the tie sections is of generally triangular configuration and the lengths thereof are all greater than the radius of the tubular structure formed • thereby.In all variations of the described methods, openings 36 and 38 such as those shown in Figs. 12 arid 14 can be appropriately made in the textile blank as desired.O PI | CLAIMS1. A garment comprising a generally tubular structure having in the upper section thereof at least two integral tie section, the locus of the profiles of said sections being of generally triangular configuration and the length of said tie sections being greater than the radius of said tubular structure, whereby said garment is adapted to multiple functions and styles and modular coordination with accessories.2. A garment according to claim 1 consisting essentially of said tubular structure and said integral tie sections.3. A garment as defined in claim 1 wherein said • tie sections are delineated by an inclined upper edge of said tubular structure and a longitudinal cut-out in said edge.4. A garment comprising a generally tubular structure of compliant material having in the upper sectio thereof at least two integral tie sections, said structure being configured to form a polygon when disposed symmetric ally in a plane whereby said garment is adapted to multi¬ ple functions and styles and modular coordinations with accessories.5. A garment as defined in claim 4 wherein said tie sections are each bounded by a curved segment of the upper edge of said polygon and a border of a longitudinal slot in said upper edge.6. A garment as defined in claim 4 wherein the upper edge of said polygon has a generally arcuate shape. 7. A garment as defined in claim 4 wherein the upper edge of said polygon has an inclined generally arcuate shape and includes a longitudinal slot.8. A garment as defined in claim 7 in which said longitudinal slot is formed of two curved segments in mirror-image relationship.9. A garment as defined in claim 4 wherein said tubular structure includes four integral tie sections.10. A garment as defined in claim 4 wherein a second longitudinal slot emanates from a lower edge of said polygon.11. A garment as defined in claim 4 wherein said tie sections have lengths greater than the radius of said tubular structure.12. A garment adapted to serve multiple functions and achieve multiple style effects comprising a generally tubular structure having in the upper section therof at least two integral tie sections, the locus of the profiles of said sections being of generally triangular configuration and the length of said tie sections being greater than the radius of said tubular structure, said structure forming a generally polygonal configuration when disposed symmtrically in a plane.13. A garment as defined in claim 12 wherein said polygonal configuration includes an upper edge having an inclined portion and a slotted portion to define said tie sections.*14. A garment as defined in claim 12 wherein said polygonal configuration includes a lower edge havingOMPI a second slotted opening emanating longitudinally therefrom15. A garment as defined in claim 12 wherein the length of said ties does not substantially exceed one half the total length of the garment.16. A method for manufacturing a garment having a generally tubular shaped configuration when disposed symmetrically in a plane, comprising bringing the long sides of a generally rectangularly shaped blank of textile material into contact with each other and forming a blank of reduced width and generally rectangular con¬ figuration, removing an inclined portion of the textile material from the blank of reduced width to form a first short side, the blank also having an opposing second short side, joining the long sides of said textile blank which were brought into contact with each other partially along their lengths to form a generally tubular shaped con¬ figuration having a longitudinal opening to thus form at least two integral tie sections, the locus of the profiles of said sections being of generally triangular configur- ation arid the lengths of said tie sections being greater than the radius of said tubular structure, whereby said garment is adapted to multiple functions and styles and modular-coordination with accessories.17. A method according to claim 16 including making openings in the generally rectangular configuration just below the lowest point of the non-parallel short side and adjacent a long side of said generally rectangular configuration.18. A method according to claim 16 including joining the long sides of the textile blank which were brought into contact with each other at an intermediate region along their lengths whereby a second opening is_O.Λ for ed which extends from the second short side of the generally rectangular configuration towards the non- parallel short side thereof.19. A method for manufacturing a garment having a generally tubular shaped configuration when disposed on the body of an individual and a generally polygonal configuration when disposed symmetrically in a plane, from a blank of textile material, comprising disposing a generally tubular shaped blank of said textile material in a plane, removing an angulated portion of said textile material from said blank to form an upper edge which is angled with respect to the lower edge thereof and forming a longitudinal opening in said upper edge to thereby define two integral tie sections, the locus of the pro- files of said section being of generally triangular configuration and the lengths of said tie sections being greater than the radius of said tubular structure, whereby said garment is adapted to multiple functions and styles and modular coordination with accessories.20. A method according to claim 19 including making openings in the generally polygonal configuration just below the lowest point of said upper edge and adjacent a long side of said configuration.21. A method according to claim 19 including forming a second longitudinal opening in the lower edge of said configuration.22. A method for manufacturing a garment having a generally tubular shaped configuration when disposed on the body of an individual and a generally polygonal con- figuration when disposed in a plane, from a blank of generally rectangularly shaped textile material comprising removing a portion of textile material from said blank and BUREAU_OMPI forming a generally arcuate curve extending from the opposite long side of said blank towards the midpoint * of said short side and forming a first short side in said blank which is non-parallel with the opposite short side therof; forming an Opening in said blank commencing at the point of intersection of said curves on said short side thereof; forming an opening in said blank commencing at the point of intersection of said curves on said short side and extending towards the opposite short side of said blank, said curves and said opening forming at least two integral tie sections, the locus of the profiles of said tie sections being of generally tri¬ angular configuration and the length of said tie sections being greater than the radius of the tubular configuration formed from said blank.23. A method according to claim 22 including making openings in the blank just below the point where the curves begin and adjacent the long side of said blank. | ROSCOE L | ROSCOE L |
WO-1979000153-A1 | 1,979,000,153 | WO | A1 | XX | 19,790,405 | 1,979 | 20,090,507 | new | G03F7 | null | B41N1, G03F7 | B41N 1/00A, G03F 7/075D | WATER DEVELOPABLE PHOTOPOLYMER PRINTING PLATES | Letterpress and offset photopolymer printing plates are disclosed having relatively thin water developable photopolymer layers, which, after being developed, have ink-repulsive, non-image areas. Adhesive layers are provided in the disclosed printing plates that are interposed between an ink-repulsive coating contained in the printing plate substrate and the water-developable photopolymer, and provide a balance between satisfactory adhesive and ink-repulsive properties in the resulting plate. The adhesive layer is also ink-repulsive and contains silicon rubber material, partially hydroiyzed polyvinyl acetate, and a water-soluble polymeric resin selected from the group consisting of water-soluble melamines, water-soluble polyesters, polyethylene glycol and cellulose. | DescriptionWater Developable Photopolymer Printing PlatesTechnical FieldThe present invention relates generally to photo-5 polymerized printing plates useful in both letterpress and offset lithography printing processes. More particularly, the present invention concerns water developable photopolymer printing plates which include (a) a support substrate coated with an in -replusive10 layer, and (b) a uniquely formulated adhesive layer which joins separate ink-repulsive and water-soluble photopolymer layers in such a manner as to provide a desired balance between the ink-repulsive and adhesive properties of the resultant printing plate.15.Background ArtIn recent years, water-developable photopolymer printing plates have been widely and quite successfully used in various relief printing processes, especially in the newspaper industry, as a consequence of the20 many practical advantages that water-developable printing plates offer over solvent-developable print¬ ing plates. It has long been recognized, for example, that photopolymer printing plates that are developable with organic solvents or aqueous alkaline solutions25 present a myriad of environmental and plate processing problems that can be readily overcome through the use of water-developable photopolymers.Yet, despite the widespread acceptance of relief-type, water-developable photopolymer plates. such plates have in the past suffered from the dis¬ advantage of requiring relatively- thick photopolymer layers, and, thus, being relatively expensive, when compared, for example, to printing plates that are conventionally used in stereotype systems employed by some large newspapers. A need has arisen, there¬ fore, for less expensive water-developable printing plates, which at least in part- can be satisfied through the use of shallow relief photopolymer printing plates.Such shallow relief photopolymer plates are capable of providing acceptable printing quality with photopolymer layers having greatly reduced thicknesses. This is accomplished through the use of relatively thin photopolymer layers that have raised image or relief areas and recessed background (non-image) areas that include an array of small protuberances. The use of background areas containing the array of protuberances has been found, for example, to prevent bottoming from occurring during the print¬ ing process, thereby enabling the use of substantially thinner photopolymer layers which, in turn, results in a substantial reduction in the cost of manufacturing such plates. While shallow-relief photopolymer plates have overcome manyof the problems of utilizing water- developable plates in letterpress printing processes, it has also been found that water-developable plates can be successfully used in offset 'lithographic print- ing processes, through the use of unique unilayer film structures having a generally continuous minor phase, e.g., a photosensitive material that cahnges solubility relative to a selected solvent upon exposure to light, and a generally discontinuousgU EAIOMPI / major phase, e.g., a particulate material which is neither photosensitive nor soluble in the solvent. Such unilayer photosensitive film structures, which are described in greater detail in co-pending application Serial No. 815,899, filed July 15, 1977, can be made selectively permeable to fluids upon exposure to light and can provide lithographic printing plates in which ink receptivity and durability of the imaging areas are realtively independent of the exposure technique and developing composition used in making a finished plate.It is, of course, desirable in both letter¬ press and of set lithography printing that printing plates utilized in such processes, at least in some cases, have non-image areas that are ink-repulsive. In the case of letterpress plates, the use of ink- repulsive, non-image background areas permits the use of relatively thick photopolymer layers, without the need for background areas containing an array of small protuberances. In addition, the incorporation of ink-repulsive, non-image background areas in letterpress plates not only allows such plates to be used in color printing, but reduces the possibility of obtaining undesired dark background areas during printing, which can sometimes occur when shallow- relief plates of the type described above are used.Similarly, in the case of offset printing plates, the use of photopolymer plates having ink-repulsive, non-image areas eliminates the need for water as the vehicle to resist deposits of ink in the non-image areas, which, in turn, eliminates the many problems, such as paper waste, and the development of special inks, papers and rollers, that are commonly associated with offset lithography printing. Heretofore, one of the major obstacles to the use-BUREAU/ OMPI of water-developable photopolymer printing plates having ink-repulsive, non-image* areas has occurred as a direct result of the difficulties experienced in obtaining strong adhesion between the water- developable photopolymer layer and the ink- repulsive coatings contained on such printing plate substrates. When the water-developable photopolymer layer was coated directly onto the ink-repulsive layer, -for example, poor adhesion often resulted. And, when intermediate adhesive layers were interposed between the photopolymer and ink-repulsive layers, strong adhesion, but poor ink-repulsive properties resulted.A need has arisen, therefore, for suitable adhesive compositions, useful in both water- developable letterpress and offset printing plates that can provide a balance between highly desirable • ink-repulsive properties and satisfactory adhesion between the separate ink-repulsive and photopolymer layers' of such printing plates.Disclosure of InventionAccordingly, the present invention is generally directed to water-developable photopolymer printing plates which include photopolymer image areas and ink-repulsive, non-image areas. Adhesive layers, which provide a unique balance between adhesive and ink-repulsive properties, are provided to join the water-developable photopolymer with an ink-repulsive coating contained on the printing plate substrate. In addition, combinations of two separate ink- repulsive layers are provided by the present invention, a first layer, comprising a highly ink-repulsive silicon rubber or equivalent composition, which covers the printing plate substrate, and a second adhesive layerBUREA that has both ink-repulsive and adhesive properties, comprising silicon rubber, selected groups of water soluble resins and controlled amounts of the water- developable photosensitive polymer used in the photopolymer layer, which joins the first ink- repulsive layer and the photopolymer layer.Best Mode for Carrying Out the InventionThe photopolymer printing plates of the present invention offer a number of advantages over many known photopolymer printing plates in that they utilize water-developable photopolymers, and, thus, avoid the necessity of employing costly and sometimes dangerous developing solvents. They result in the preparation of plates that require relatively thin layers of photopolymer, without sacrificing printing quality. They result in the preparation of printing plates that have ink-repulsive, non-image areas, and, thus, are particularly suited for use in letterpress and offset lithography printing. They include uniquely formulated ink-repulsive layers which have the capability of providing both strong adhesion between ink-repulsive coatings contained on the plate substrate and the water developable photopolymer. When used in offset lithography, they eliminate the need for water in the printing process, and, thus, reduce the cost, complexity and amount of paper wasted in conventional offset printing. And, when used in letterpress printing, they eliminate the need for an array of small protuberances in the non-image background areas, and yet still provide high quality printing with relatively low thickness photopolymer layers.The photopolymer plates of the present invention generally include the following elements: (a) a support substrate, (b) an ink-repulsive coating contained on the support substrate, (c) a water- developable photopolymer layer, and (d) an ink- repulsive adhesive layer which advantageously joins the photopolymer and ink-repulsive layers in a manner that imparts both satisfactory adhesion and acceptable ink-repulsive characteristics to the resultant printing plate. Although any suitable support substrate material can be used in the practice of the present invention, it has been found that satisfactory results can be achieved with metal substrates, such as aluminum or steel, or polyester or related polymeric substrates, indeed, even with paper substrates in some instances. Preferably the photopolymers used in the practice of the present invention are water-developable. In the case of letterpress plates, the photopolymer compositions found particularly useful are those which include: (a) at least one unsaturated ethylenic monomer, preferably having a boiling point about 100°C, molecular weight below 1500 and 1 to 4 polymerizable ethylenic groups, and being polymerizable by actinic light in the presence of a photopolymerization initiator; (b) a photopolymerization initiator; and (c) a partially saponified polyvinyl acetate, namely a polymer having both acetyl groups and hydroxy groups produced by saponification or hydrolysis of polyvinyl acetate and the like and being water-soluble and ' compatible with the monomer component of (a) . The partially saponified polyvinyl acetate used in the photopolymer composition described above preferably has an average degree of polymerization of 300 to 2000 and a saponification degree of 65 to 99 mole percent. If a suitable partially saponified polyvinyl acetate cannot be obtained by saponifying polyvinyl acetate having a low saponification degree as a homopolymer, a copolymer obtained, for example, by copolymerizing vinyl acetate with aleic anhydride can be partially saponified to give the desired polymer. Saponification as used herein is intended to mean the conversion of ester groups or the like into hydroxy groups and the saponification degree represents the extent to which ester groups or the like have been converted to hydroxy groups. Degree of polymerization, as used herein, is intended to represent the molecular weight and viscosity of the polymer, as indicated in Davidson and Sittig, Water-Soluble Resins (1962) at page 89.Such water-developable photopolymer compositions are described in far greater detail in United States Patents .Nos. 3,801,328 and 3,877,939, the disclosures of which' are incorporated herein by reference. In the case of offset plates, the photopolymer compositions found particularly useful are those which include a minor phase material uniformly interdispersed with a major phase material; the minor phase being photosensitive, generally continuous through the structure and capable of changing solubility with respect to a given solvent, and the major phase being a discrete particulate material which is not photosensitive and is chosen to be relatively insoluble in the solvent for the minor phase. Among the photosensitive materials useful as the minor phase in such compositions are any photo¬ sensitive compound wherein exposure to electromagnetic radiation creates a change in solubility characteristics in a selected solvent, including, for example, aromatic diazo compounds, light sensitive dyestuffs, azo compounds, dichromates, photopolymers, and silver halide gelatin systems, and particularly condensation products of aldehyde compounds, such as formaldehyde or paraformaldehyde, and a diazo compound such as 4-diazo-l, 1'-diphenylamine.Included among the homopolymers and copolymers, in emulsion-dispersion form, which are suitable for use as the major phase in such compositions are: acrylics, copolymers of acetate and ethylene, copolymers of styrene- and acrylates, polyvinyl acetates, and copolymers of vinyl acetate and acrylates. ■ Each of these may be used with or without protective colloids, wetting agents, plasticizers and other modifying agents.Such water-developable photopolymer compositions are described in greater detail in United States Application Serial No. 815,899, filed July 15, 1977, the disclosure of which is likewise incorporated herein by reference.As noted above, a separate ink-repulsive layer is desirably coated onto the support substate to provide ink-repulsive properties for the non-imaged areas of the developed plate. Although a number of ink-repulsive compositions can be used in the practice of the present invention, commerically available silicon rubber or silicon oils are prefer¬ ably used. Such silicon rubbers or oils typically comprised polysiloxane compositions that are generally characterized by the presence of the following repeating unit in their polymeric structural chain: n wherein R, and R , which may be the same of different, represent hydrogen, an alkyl group, halogen, phenyl or a halogenated alkyl. Representative of the preferred polysiloxane compositions useful in the practice of the present invention are those provided commercially by Dow Corning under the trade name Silicone SYL OFF 23. . ■'The ink-repulsive adhesive layer of the present invention joins the water-developable photopolymer layer to the ink-repulsive polysiloxane layer present on the support substrate, and desirably includes: (a) silicon rubber or oil, (b) select water-soluble resins, and (c) partially saponified polyvinyl acetate. As a consequence of the compatibility between the ink-repulsive adhesive layer and both the photopolymer and ink-repulsive layers described above, the ink-repulsive adhesive layer is preferably formulated to impart a satisfactory balance between adhesion and ink-repulsion in the developed printing plate. • Thus, if too much silicon rubber or oil is included in the ink-repulsive adhesive layer , ink-repulsion characteristics are acceptable, but adhesion is poor. Similarly, if too much water soluble resin is included in the ink-repulsive layer formulation, adhesion is improved, but the ink- repulsive characteristics of the developed plate are unacceptable.Accordingly, it has been determined that-BTJREATTOMPI through the proper selection of components and the relative ratios of such components in the ink- repulsive adhesive layer, an acceptable balance* between adhesion and ink-repulsion can be accomplished. Although partially saponified poly¬ vinyl acetate is itself a water-soluble composition, it has been found that the use of other select water-soluble polymeric resins in combination with the partially saponified polyvinyl acetate improves the properties of the ink-repulsive adhesive layer. The use of such select water-soluble resins, for example, improves the adhesive properties of the layer over polyvinyl acetate alone, and improves the durability of the resultant printing plate, since the partially saponified polyvinyl acetate can sometimes be softened with water, even after curing, while the select water-soluble resins cannot be easily softened with water after curing.It has been found, for example, that the following water-soluble polymeric resins are particularly well suited for use in the ink-repulsive adhesive layer: water-soluble melamines, such as methylol elamine, water-soluble polyesters, polyethylene glycol and cellulose. The water-soluble melamines are particularly preferred because they partially cross-link with the polyvinyl acetate when heating, which, in turn, provides an even more durable printing plate. The polyethylene glycol component when used has the formula HO (CH2CH20)n H, wherein n is between 5 and 80, and preferably between 10 and 30. The cellulose component, when used, generally has the formula:PI wherein R is -CH 3 ' -CH2CHCH3 , or -CH2CHCH2CH3 , andOH OH the resultant cellulose composition has a molecular weight between 10,000 and 100,000, and preferably between 20,000 and 60,000.Similarly, it has been determined that, when partially saponified or hydrolyzed polyvinyl acetate is employed in the photopolymer composition, partially hydrolyzed polyvinyl acetate having a preferred hydrolysis degree of about 70 to 95 percent and a polymerization degree between 300 and 2,000 is desirably used in the ink-repulsive adhesive layer composition. It has been found that the use of partially hydrolyzed polyvinyl acetate in the ink-repulsive adhesive layer not only promotes strong adhesion with the photopolymer layer, but is fully compatible with the photopolymer layer. Even when polyvinyl acetate is not used in the photopolymer layer, however, it has still been found, desirable to use polyvinyl acetate in the ink-repulsive adhesive layer because the polyvinyl acetate can be easily washed with water during development of the plate thereby exposing the silicon rubber or oil layer in the undeveloped recess areas of the plate, thus improving the ink-repulsive character of those areas, while still maintaining a desirably strong adhesion in the developed relief areas of the plate.Preferably, the ratio of water-soluble resin to silicon rubber or oil used in the ink-repulsive-BUREATΓOMPI adhesive layer is between about ,0.1 to 1 part by weight resin to each part by weight of silicon rubber or oil. As noted above, the use of too much. silicon oil results in poor adhesion, while the use of too little relative to the amount of water- soluble resin used results in poor ink-repulsive properties.Likewise, it has been found that the preferred ratio of water-soluble resins to partially hydrolyzed polyvinyl acetate used in the formulation is between about 0.1 to 2 parts by weight water-soluble resins to 1 part by weight polyvinyl acetate. The use of excessive amounts of water-soluble resins outside the preferred range can, and often does, result in the formation of an undesired gel.The ratio of polyvinyl acetate to silicon rubber is also desirably maintained in a range from about 0.1 to 2 parts by weight polyvinyl acetate to 1 part by weight silicon rubber. Most preferably, however, the ratio by weight of polyvinyl acetate to silicon rubber is maintained between 0.25 to 0.5 on a parts by weight basis.The relative thicknesses of the separate silicon oil ink-repulsive and ink-repulsive adhesive layers, of course, are to some extent dependent upon final characteristics designed in the developed plate. Preferably, however, the thickness of the ink-repulsive adhesive layer is maintained between 5 to 100 microns, and most preferably between 10 to 30 microns, in order to provide the desired balance of adhesion, ink-repulsion and cost. When the ink-repulsive adhesive layer is made too thick, for example, light tends to scatter from the layer during exposure and the developed plate has an undesired rough surface. Conversely, if the ink- repulsive adhesive layer is made too thin, the layer is readily eroded during operation and the developed plate has unsatisfactory durability. The thickness of the silicon rubber layer contained in the support substrate is desirably main¬ tained between about 2 to 30 microns, and preferably between 5 to 10 microns so that the support substrate is adequately covered, and, thus, not exposed after prolonged use of the developed plate. Through the use of two ink-repulsive layers (a first layer covering the support substrate and a second adhesive layer joining the photopolymer and first ink-repulsive layers) , it has been found that the overall ink- repulsive characteristics of the developed plate are greatly enhanced. The adhesive ink-repulsive layer is generally not sufficiently thick itself to sithstand severe printing environments or prolonged use, and, thus, would be rapidly eroded away, and thus expose the support substrate, were it not for the first silicon rubber ink-repulsive layer. Nonetheless, the adhesive ink-repulsive layer is both ink-repulsive and slightly water- soluble. Thus, after development, portions of the adhesive layer are washed away in the' non-image areas to expose portions of the silicon rubber layer and further enhance the ink-repulsive characteristics of the developed plate. In addition, the adhesive layer itself, if desired, can be partially removed. with organic solvents such as xylol or toluol to improve the ink-repulsive character of the developed plate even further.It should, of course, be understood that in some instances a single layer of silicon rubber or oil, polyvinyl acetate and select water-soluble resins can be employed in place of the separate layers described above. In those instances, the separate silicon rubber or oil layer is eliminated, and a single layer of silicon rubber, partially saponified polyvinyl acetate and select water-soluble resins in the relative proportions set forth above is applied to the printing plate substrate. Although such single layers are less durable than a two layer structure because portions of the silicon rubber or oil tend to wash away with the polyvinyl acetate dur¬ ing development, they are more desirable from a cost and ease of manufacture standpoint because of the elimination of one of the two layers needed to provide both adhesive and ink-repulsive characteristics to the resultant printing plate.Several embodiments of the present invention are illustrated in the following examples. All parts and percentages are by weight unless otherwise indicated.EXAMPLE 1A. Silicon SYL OFF 23 (Dow Corning) (40 parts) and S-2260 primer (Dow Corning) (5 parts) are mixed in xylene (55 parts) . Half a percent of • 23A catalyst (Dow Corning) based on total weight is added to this solution and the solution is stirred for 15 minutes at room temperature. The resulted solution is cast on an oil-free 10- mil thick aluminum plate and dried for 15 minutes at 120°C. to form silicone layer 20 microns in thickness.B. The solution (10 parts) which consists of 20 parts of partially saponified polyvinyl acetate(average polymerization degree, 500; saponification degree, 82.0 mol %) and 80 parts of water, and 1.5 parts of methylated methylol melamine in water (commercial name: Resloom M-75, solid 60%, by Monsanto) are'added to 75 parts of silicone solution which is prepared by dissolving 50 parts of Silicone SYL OFF 23 and half a percent of 23A catalyst based on the weight of Silicone SYL OFF 23 into 50 parts of benezene. The resulted solution is cast on the plate which is described in Method A and dried for 20 minutes at 130°C. to form second layer 5 microns in thickness.EXAMPLE 2The solution (15 parts) which consists of 20 parts of partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 82.0 mol %) and 80 parts of water, and 15 parts of 20% water solution of polyethylene glycol (molecular weight 800-1100) are added to 70 parts of silicone solution which is prepared by dissolving 50 parts of Silicone SYL OFF 23 and half a percent of 23A catalyst based on the weight of Silicone SYL OFF 23 into 50 parts of benzene. The resulted solution is cast on the plate which is described in Method A of Example 1 and dried for 20 minutes at 130°C. to form second layer 10 microns in thickness.EXAMPLE 3 The solution (15 parts) which consists of 25 parts of partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 78.0 mol %) and 75 parts of water, and 10 parts of 20% water solution of polyethylene oxide polymer (commerical name Polyox WSR-N-80 by Union Carbide Corporation, approximately molecular' weight of 200,000) and added to 75 parts of a silicone solution which is prepared by dissolving 50 parts of Silicone SYL OFF 23 and one percent of 23A catalyst based on the weight of Silicone SYL OFF 23 into 50 parts of xylene. The resulted solution is cast on the plate which is described in Method A of Example 1 and dried for 20 minutes at 130°C. to form second layer 5 microns in thickness.t EXAMPLE 4A mixture of partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 82.0 mol %) (35 parts), water (30 parts) and Rose bengal (50 ppm of all components by weight) is kneader at 80 to 90 degrees centigrade for 30 minutes. Then, this mixture is cooled to 60 degrees centigrade and a mixture of diethylene glycol dimeth- acrylate (10 parts) , B-hydroxyethyl methacr late (24 parts), hydroquinone (0.1 percent of total monomer by weight) and benzoin isopropyl ether (1.0 part) is added and stirred for 30 minutes. The resulted photopolymerizable composition is cast on the plate which is described in Method B of Example 1. A polyester sheet is placed thereon and the resulted piled product is passed between two rolls. After cooling, the polyester sheet is peeled off and the plate is dried in a dryer at 75°C. for 20 minutes to form photosensitive layer 7 mils in thickness.EXAMPLE 5A mixture of partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 77.0 mol %) (14 parts), methylated methylol melamine (commercial name: Resloom M-75, solid 60%, by Monsanto) <6 parts) , water (30 parts) and Eosin (25 ppm of all components by weight) is kneaded in a kneader at 70°C. for 25 minutes. This mixture is cooled to room temperature and a mixture B-hydroxypropyl methacrylate (20 parts) , benzoin isopropylether (1 part) , zinc acrylate (5 parts) and methyl alcohol (24 parts) is added and stirred for 30 minutes at room temperature. The resulted photopolymerizable composition is cast on the plate which is described in Example 2. A polyester sheet is placed thereon and the resulted piled product is passed between two rolls. After cooling, the polyester sheet is peeled off and the plate is dried in a dryer at 75°C. for 3 minutes to form photosensitive layer 5 microns in thickness.The photopolymer plate made according to Example 4 is placed in a vacuum frame and exposed to a 3,000 watt high pressure mercury arc for 3 seconds from a distance of 20 inches. Then, a negative film is placed on the photopolymer plate and the plate is exposed to same actinic light through the negative film for 25 seconds. After exposure, the negative film is stripped from the plate and the unexposed polymer is washed away with water (temperature, 115°F.) under the pressure of 40 psi for one and a half minute. .The printing plate is dried at 250°F. for one and half minute to give a sharp relief printing plate. The resulting printing plate is mounted on a Vandercook letterpress printing machine (Universal III) , and shows excellent image quality without any smutting on non-image area.The photopolymer plate made according to Example 5 is placed in a vacuum frame and the photopolymerizable surface is brought into contact with a negative film. Then, the plate is exposed to a 3,000 watt high pressure mercury arc for 2 and a half minutes. After exposure, the unexposed polymer'is removed by wiping with cotton rag using water and followed by wiping with cotton rag with hydrocarbon solvent like mineral spirit. The plate is dried at 15 degrees Fahrenheit for 1 minute. The resulting printing plate is mounted on an offset printing machine (Multilith 1250) from which water supply device has been removed, and shows excellent image quality without any smutting on non-image area.Of course, it should be understood that various changes and modifications to the preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications be covered by the following claims. | Clai s. A water—developable photopolymer printing plate comprising a substrate having applied thereto at least three additional layers of material disposed in a superimposed relation to one another, said layers comprising: a) a first ink-repulsive layer of silicon rubber material substantially covering said substrate, .. b) a water-developable photopolymer layer, and,10 c) a second ink-repulsive and adhesive layer joining said first 'ink-repulsive and said photopolymer layers comprising a silicon rubber material, partially hydrolyzed poly¬ vinyl acetate, and a water-soluble polymeric15 resin selected from the group consisting of water-soluble melamines, water-soluble polyesters, polyethylene glycol and cellulose.2. The printing plate of claim 1 wherein said silicon rubber material comprises a polysiloxane 20 characterized by the presence of the following repeating unit in its polymeric structural chain; wherein R.. and 2 may be the same or different,' and are selected from the group consisting of25 hydrogen, an alkyl group, halogen, phenyl and a halogenated alkyl.3. The printing plate of claim 2 wherein the water- developable photopolymer layer comprises:-gυREA TOMPI a) at least one unsaturated ethylenic-monomer having a boiling point about 100°C, a molecular weight below 1500 and 1 to 4 polymerizable ethylenic groups, and being polymerizable by actinic light in the pre¬ sence of a photopolymerization initiator; b) a photpblymerization initiator; and c) a partially hydrolyzed polyvinyl acetate.4. The printing plate of claim 3 wherein the partially hydrolyzed polyvinyl acetate in said - second layer has a hydrolysis degree of about 70 to 95 percent, and a molecular weight in the range of about 300 to 2000.5. The printing plate of claim 2 wherein said photopolymer layer is a film structure comprising a generally continuous phase and a generally discontinuous phase, said continuous phase being a minor constituent of said structure and comprising a photosensitive material whose solubility with respect to a given solvent is changed upon exposure to electro-magnetic radiation, said discontinuous phase being a major constituent of said structure and comprising a particulate material which is substantially insoluble in said solvent, said phases being uniformly interdispersed throughout the entire film structure, and said 'film structure having a maximum thickness not greater than about ten times the average diameter of the particles comprising said major phase material.6. The printing plate of claim 2 wherein the ratio of water-soluble resin to silicon rubber material in said second layer is between about 0.1 to 1 part by weight resin to each part by weight silicon rubber or oil.7. The printing plate of claim 2 wherein the ratio of polyvinyl acetate to silicon rubber in said second layer is between about 0.1 to 2 parts by weight polyvinyl acetate to 1 part by weight silicon rubber.8. The printing plate of claim 2 wherein the ratio of water-soluble resins to polyvinyl acetate in said second layer is between about 0.1 to 2 party by weight resins to 1 part by weight polyvinyl acetate.9. A water-developable printing plate comprising a substrate having applied thereto an ink-repulsive, adhesive layer joining said substrate to a water- developable photopolymer layer, said ink-repulsive adhesive layer comprising: a) a polysiloxane characterized by the presence of the following repeating unit in its polymeric structural chain; wherein R.. and R2 may be the same or different, and are selected from the group consisting of hydrogen, an alkyl group, halogen, phenyl and a halogenated alkyl; b) partially hydrolyzed polyvinyl acetate having a hydrolysis degree of about 70 to 95 percent and a molecular weight in the range of about 300 to 2000; and c) at least one water-soluble polymeric resin selected from the group consisting of water- soluble melamines, water-soluble polyesters, * polyethylene glycol and cellulose.10. The printing plate of claim 9 further characterized by having a first ink-repulsive layer of ■ polysiloxane interposed between said substrate - and said ink-repulsive adhesive layer.- | NAPP SYSTEMS INC | KIMOTO K; OKAI S |
WO-1979000156-A1 | 1,979,000,156 | WO | A1 | EN | 19,790,405 | 1,979 | 20,090,507 | new | B23Q7 | null | B23Q1, B23Q3, B23Q7, B23Q16 | B23Q 1/38, B23Q 16/00C, B23Q 7/14K | CENTERING PIN FOR AIR FLOAT MACHINE TOOL TABLES | A centering pin (80) fur use in a machine tool work table (28) of the type in which a workpiece fixture (32) is supported on a film of pressurized air thereby enabling substantially friction free movement of the fixture (32) on the table surface (30). The centering pin (80) comprises an outer pin (90) mounted within the table (28) and projecting above the table upper surface (30), an inner pin (92) received within the outer pin (90) for reciprocal movement along a direction generally normal to the table surface, a hydraulic actuator (82, 94) for causing the inner pin (92), to project above the outer pin (90) at a first vertical position, and a spring (102) for causing the inner pin (92) to retract to a second vertical position below the first vertical position when the fluid actuator (82, 94) is deactivated. The fixture (32) has one or more slots (182) which ride over the outer pin (90) and a plurality of holes (124) within the slots which are adapted to be engaged by the inner pin (92) when it is extended to its upper vertical position, thereby enabling controlled translation and rotation of the fixture (32) on the table (28). A safety feature is provided wherein if the slot (182) is not engaged by the outer pin (90) when the fixture (32) is placed on the table (28), air floatation pressure cannot be supplied between the fixture (32) and table surface (30). | CENTERING PIN FOR AIR FLOAT MACHINE TOOL TABLESTECHNICAL FIELD The present invention relates to means for locating a workpiece fixture on a table during movement thereof from one machining position to another and in particular to a dual centering pin apparatus which selectively en¬ gages one or more slots and openings on the downwardly facing surface of the fixture so as to provide controlled translation and rotation thereof.BACKGROUND OF INVENTION In standard machining practice, the machining of workpieces of any substantial size involves time consum¬ ing, laborious repositioning of the workpiece as various regions of the work are to be machined. Often, it be¬ comes necessary to use hoists and other power devices for elevating and moving the workpiece about and for low¬ ering the workpiece into the proper position for the machining of respective regions of the workpiece. Addi- tionally, precise positioning of the workpiece in a selected position under such conditions is difficult and cannot always be achieved with the desired accuracy.In order to overcome these problems, an air float table wherein the workpiece is supported on a film of pressurized air has been developed. Such a table, which is described in U. S. patent application Serial No. 684,725, is provided with fluid passages and a plurality of fluid outlets distributed over the surface of the table so that a cushion of pressurized air may be pro- -2- vided underneath the workpiece fixture. By virtue of the fluid pressure film, substantially friction free movement of the fixture on the table is possible thereby permitti positioning and repositioning to be accomplished by a single operator without the need for extraneous hoisting equipment.In order for th ^ fixture to be rotated and transla¬ ted from one position to another, the table may be pro¬ vided with a main pivot pin which projects upwardly from the table surface. The pin may be receivable in a socket in the bottom of the fixture in which case the fixture is constrained to move circularly on the table. Alternative ly, the socket may be replaced by a slot so that the fix¬ ture is not only rotatable on the bed but is translatable thereon in various desired directions. Cooperating ele¬ ments of retractable pin and socket locating devices on the fixture and table provide for location of the fixture in predetermined positions on the table. Clamps are also provided to clamp the fixture in the located 'positions on the table during machining.Although an air float system of this type is advantageous in repositioning heavy workpieces, there are certain attendant dangers which result from the substan¬ tially friction free relationship between the workpiece fixture and the table surface. For example, the work¬ piece and fixture can slide off the table if the opera¬ tor does not exercise extreme caution during reposition¬ ing to assure that he has it fully under control. The tremendous masses of large workpieces and the high mo- menta which result when they are moved, however, make it difficult to stop the workpiece manually. Obviously, the potential for injury to the operator and damage to the workpiece and machine is very great.Another problem is that of accurately stopping the workpiece at the desired position for subsequent engage¬ ment of the locating pins and sockets. The operator must therefore search for the desired position through repeated trial and error thereby resulting in a loss of productive machining time. In the case where the fixture is provided with a pair of crossed slots for dual translation, it is difficult for the operator to determine when the centering pin is located at the intersection of the two slots so that movement from one slot to the other can be accom¬ plished. Accurately located rotation centers at various locations within the slots is also desirable for multiple machining operations.DISCLOSURE OF INVENTION The present invention overcomes the disadvantages of the prior art by providing a dual centering pin received within the table and comprising an outer pin which is en- gageable with the fixture slots, an inner pin received within the outer pin, and means for causing the inner pin to extend upwardly out of the outer pin so as to engage holes in the slots. When the inner pin is retracted, the workpiece fixture is translatable on the table in engage- ment with the outer pin and when the inner pin is extended and received within one of the fixture holes, the fixture may be rotated thereabout to the desired position. By providing a plurality of intersecting slots and a plural¬ ity of holes at various positions within the slots, a variety of rotation centers and translation paths are possible.The outer pin may be slidably received in the table and in this case sensing means are provided to prevent the supplying of pressurized air between the fixture and table when the outer pin is depressed, as in the case where the fixture is lowered on the table with the slot out of align¬ ment with the centering pin. If air pressure were applied without the fixture positively engaged by the centering pin, it could slide off the table and cause injury to the operator or damage to the workpiece or machine.Specifically, the present invention is particularlyO PI adapted for use in apparatus for supporting a work member in a machine tool for machining thereof having a table with a horizontal upper surface adapted to support a work¬ piece fixture thereon and means for supplying fluid under pressure between the table and fixture. It comprises an outer pin mounted within the table and projecting above the table upper surface, an inner pin being received within the outer pin for movement along a direction generally normal to the table surface, and means for selectively causing the inner pin to project above the outer pin at a first vertical position and alternatively for causing the inner pin to retract to a second vertical position below the first vertical position. In the case where the outer pin is slidably received in the table for rectilinear movement along a direction normal to the table surface, a safety feature is provided comprising means for interrup¬ ting the supply of fluid under pressure between the table and workpiece fixture supported thereon when the outer pin is depressed below a given vertical height relative to the table surface.The method according to the present invention relates to locating a workpiece fixture having a downwardly facing bottom surface, a slot in the bottom surface and a hole in the slot, in a machine tool, for example, having a table with an upwardly facing upper surface for supporting the fixture during machining of the workpiece and a first pin extending upwardly out of the table surface. The method comprises: supporting a fixture on the table with the table and fixture surfaces in facing relationship and with pin received in the slot, supplying a fluid under pressure between the fixture and table surfaces to provide sub¬ stantially friction free support of the fixture on the table, causing a second pin having a smaller diameter than the first pin to project upwardly out of the first pin and urge against the fixture slot, moving the fixture on the table such that the slot slides over the first pin until the second pin engages the hole in the fixture, ro¬ tating the fixture about the second pin to a predetermined position on the table, and causing at least one pair of lo¬ cating elements on the table and fixture surfaces to inter- engage so as to lock the fixture in the predetermined position on the table.It is an object of the present invention to provide a dual centering pin which is always in engagement with the fixture slot or slots and is selectively engageable with holes in the fixture slots so as to provide a plurality of rotating centers.Another object of the present invention is to provide a dual centering pin apparatus wherein the supply of pneu¬ matic pressure between the fixture and table is blocked when the centering pin and fixture are not interengaged for controlled horizontal movement.A further object of the present invention is to pro¬ vide a dual centering pin which enables rapid and accurate repositioning of the workpiece from one machining position to another.Another object of the present invention is to provide a dual centering pin which may be easily incorporated into existing air float machine tool tables.These and other objects and features of the present invention will become more apparent upon reference to the detailed description taken in conjunction with the accom¬ panying drawings.BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a machine tool incor- porating the centering pin of the present invention;Figure 2 is a top plan view of the table of Figure 1 showing the workpiece fixture in two different positions;Figure 3 is a top plan view of the table shown in Figure 1; Figure 4 is a bottom plan view of the workpiece fix¬ ture;-BU E TΓOMPI. , WIPO Λ< Figure 5 is a sectional view of one of the valved con¬ nections leading from a passage in the table to the surface on which the workpiece fixture is supported;Figure 6 is a sectional view of one of the locating pins shown engaged with a corresponding socket in the lower surface of the workpiece fixture;Figure 7 is a schematic of the hydraulic system ac¬ cording to the invention;Figure 8 is an enlarged plan view of the centering pin;Figure 9 is an enlarged sectional view of the center¬ ing pin in its fully extended position; andFigure 10 is an enlarged sectional view.of the cen¬ tering pin which has been depressed by the workpiece fix- ture.BEST MODE FOR CARRYING OUT THE INVENTION Referring now to the drawings. Figure 1 is a per¬ spective view of a machine tool having, a bed 20 supported on ways 22 and 24 and a working tool 26, which may be a boring tool, milling tool or the like according to well known practice in the machine tool art. A table or plate 28 is fixedly secured to bed 20 and includes an upper sur¬ face 30 on which is supported a workpiece fixture 32 having a workpiece 34 mounted thereon. Table 28 is provided with a plurality of fluid passage ways 36 (Figure 5) which are connected via a control valve 37 (Figure 7) with a supply of fluid under pressure. The fluid is preferably air, but could conceivably comprise other fluid media. Passageways 36 extend upwardly through table 28 and communicate with openings 38 in the surface30 of table 28. As shown in Figure 3, there are many such openings 38 distributed over the table surface 30 so as to provide a film of pressurized air wherever the fixture 32 is positioned. The upper end of each passageway is closed by a valve comprising a body 40 which may be threaded intoOM passageway 36 and the top of which is disposed slightly be¬ low the level of table surface 30. Valve body 40 is tubu¬ lar and has captured therein a valve ball 42 which projects slightly above the surface 30 of table 28 as shown in Fig- ure 5. A spring 44 urges ball 42 into its upper closed position in which it contacts circular valve seat 46. When the fixture 32 is moved on table 28 and the downwardly facing surface 48 of fixture 32 engages ball 42, ball 42 will be depressed as shown in Figure 5 and admit air under pressure from passageway 36, between seat 46 and ball 42 to the space between surfaces 48 and 30. The pressure of the fluid is so adjusted that a fluid film will be established which will floatingly support fixture 32 thereon. This enables the fixture to be eas- ily moved about on table 28 to the desired position.Obviously, when the supply of fluid is interrupted, fix¬ ture 32 will come to rest directly on table surface 30. Each opening 38 includes a valve identical to that shown in Figure 5. It is essential that the workpiece 34 be accurately located for machining, and to this end, table 28 includes a plurality of locating pins 50 which serve to lock the fixture in various predetermined positions. The locating pins 50 are located in precise positions on table 28 with reference to tool 26. These pins 50 are engageable with sockets 52 in the bottom surface 48 of fixture 32 and which are also accurately located within fixture 32 with reference to the location of pins 50. Thus, when one or more pins 50 engage the corresponding sockets 52, the fixture 32 will be in an accurately located position on table 28.Table 28 is provided with bores 54 each of which at the upper end thereof has an elongated bushing 56. Pin 58, having a tapered upper end 60 adapted for seating in the corresponding tapered bushing 62 in socket 52, is slidably received in bushing 56. At the lower end thereof. pin 58 is connected to a double acting piston 64 biased upwardly by spring 66 to the position shown in Figure 6. Each piston 64 has an upwardly facing fluid surface 68 adapted to be acted on by fluid from passageway 70 to drive the piston 64 and pin 58 downwardly until the upper end 60 of pin 58 is below the upper surface 30 of table 28. Alternatively, a supply of fluid pressure to the downwardly facing surface 72 from passageway 74 will drive piston 64 upwardly to effect firm engagement of the ta- pered end 60 with bushing 62. The lower end of bore 76 is closed by a cover plate 78. As shown in Figure 3, table 28 is provided with a plurality of locating pins 50 so tha a number of successive machining positions for workpiece 34 and fixture 32 may be realized. By supplying air under pressure to the upper side 68 of piston 64, pin 58 will be moved downwardly out of bush¬ ing 62. If fluid under pressure is then introduced be¬ tween fixture 32 and table 28, fixture 32 may be moved to the desired position. With fixture 32 in this position, pneumatic pressure is vented from passageway 70 and pin58 will move upwardly under the pressure of spring 66 un¬ til its tapered portion 60 engages bushing 62. Pin 58 may be driven with more force into bushing 62 by admitting pressure through passageway 74. With the fixture 32 ac- curately located in this manner, the supply of pneumatic pressure between fixture 32 and table 28 is then termin¬ ated and fixture 32 will come to rest on surface 30. Fixture 32 may be clamped to table 28 by means of bayonet clamps 80 and 82 which are shown generally in Figure 1 and described in greater detail in pending U. S. patent application Serial Number 829,358 entitled Bayonet Clamp¬ ing Apparatus for Machine Tools. Additional details re¬ lating to the above-described aspects of the air float table may be found in pending U. S. patent application Serial No. 684,725.The centering pin 80 according to the present inven- tion is shown in detail in Figures 8, 9 and: 10. It com¬ prises a cylinder 82 which is received within bore 84 in table 28 and secured thereto by means of screws 86 and 88, a generally tubular outer pin 90 reciprocally received within cylinder 82, and an inner pin 92 reciprocally re¬ ceived within outer pin 90 and cylinder 82 and having a flanged piston portion 94 at its lower end. O-rings 96 and 98 seal cylinder 82 against bore 84 and seal 100 seals piston 94 against cylinder 82. A coil spring 102 is positioned around inner pin 92 and, when compressed, urges piston 94 and therefore pin 92 downwardly and outer pin 90 upwardly. The upward dis¬ placement of outer pin 90 is limited by shoulder Ϊ04 coming into contact with screw 106 and ring 134. Pressurized fluid, either a hydraulic fluid or air, is admitted to the working chamber 108 of cylinder 82 through fitting 110. Referring now to Figure 4, the lower surface 48 of fixture 32 is provided with a pair of intersecting slots 112 and 114 which terminate short of the edges of fixture 32, and a plurality of holes 116, 118, 120, 122 and 124 in slots 112 and 114. Although the exact location of holes 116 through 124 depends upon the particular machin¬ ing requirements, it is generally preferable that at least one hole 124 be located at the intersection of the slots 112 and 114. When pins 90 and 92 are fully extended as shown in Figure 9, outer pin 90 will be received in one of the slots 112 or 114 and inner pin 92 will engage one of the holes 116 through 124, fixture 32 can be rotated about the particular hole so engaged. With inner pin 92 re- tracted to a vertical position below holes 116 through124, fixture 32 may be translated along one of its slots 112 or 114, which is in engagement with outer pin 90. It should be noted that even though inner pin 92 may be re¬ tracted as by interrupting the supply of fluid under pres- sure to chamber 108, outer pin 90 will remain in fully ex¬ tended position unless physically depressed by an externaliUREAtT OMPI force, such as the lower surface 48 of fixture 32.In order to assure that fixture 32 can never acciden¬ tally slide off table 28, a safety feature, which inter¬ rupts the supply of pressurized fluid between fixture 32 and table 28 when outer pin 90 is depressed, is provided. As shown in Figures 8, 9 and 10, it comprises: an elec¬ trically conductive plunger 126 reciprocally received within a bore 128 in outer pin 90 and urged upwardly by compressed spring 130 retained within bore 128 by plug 132, an electrically non-conductive ring 134 secured to table 28 by screw 136, a metal contact plug 138 received within ring 134 and connected to an insulated electrical wire 140. As long as outer pin 90 is extended so that it is at least partially received within slot 112 or slot ' 114, metal plunger 126 will contact plug 138 through the action of compressed spring 130. Once outer pin 90 has been depressed to a vertical height at or near the level of table surface 30, its shoulder 142 will engage the * shoulder 144 of plunger 126 and force it downwardly out of contact with plug 138 as shown in Figure 10. As will be described in greater detail in connection with Figure 7, this causes the supply of pneumatic pressure between fixture surface 48 and table surface 30 to be blocked so that fixture 32 cannot accidentally slide off table 28. A simplified representation of the hydraulic and electric circuits in connection with the safety interlock described above is shown in Figure 7. A source of fluid under pressure is supplied through conduits 146 and 148 to the fluid inlets of valves 150, 152 and 154. Valves 150 and 152 are three-position valves and operable for reversibly connecting the fluid inlet to one or the. other of the surface conduits connected thereto while exhausting the other surface conduit, and also include a center po¬ sition in which both of the service conduits are connected to' exhaust. Valve 150 has one service line connected to the upwardly facing sides of a pair of locating pin ac- tuating pistons 156 and 158 and the other service line connected to-the downwardly facing side of the pistons 156 and 158. Similarly, valve 152 has one service line connected to the upwardly facing sides of pistons 160 and 162 for the locating pins 50 and the other service conduit connected to the downwardly facing sides of the pistons 160 and 162.The conduits leading to the downwardly facing sides of the pistons 156 through 162 are connected through needle valves (not shown) , if desired, a check valve 164 and selector valve 165 to a pilot cylinder 166 on rever¬ sing valve 154. Valve 154 is normally held in position to supply pressure.to conduit 168 by spring 170 but will move into position to exhaust conduit 168 when the pres- sure in pilot cylinder 156 reaches a predetermined amount. Thus, when valves 150 and 152 are actuated to drive the locating pin 50 upwardly into locating position, after the pins 50 become seated, the pressure built up on the underneath sides of the pistons 156 through 162 will cause valve 154 to shift to interrupt the supply to the fluid cushion for fixture 32. Of course, the sequence of steps could be entirely under the control of manual valves, if so desired.Centering pin 80 is supplied with fluid pressure through conduit 172 under the control of valve 174. Wire 140 is connected to a ground sensing device 176 which in turn is connected to solenoid valve 178. Ground sensing device 176 is adapted to provide a first output when wire 140 is isolated from electrical ground and a second electrical output when wire 140 is connected to ground.An exemplary detector is the Minster Micro-current Detec¬ tor Unit Bul-010-6056 described in technical bulletin No. 105 of The Minster Machine Company, Minster, Ohio, U.S.A. Solenoid valve 178 is is fluid communication with pilot cylinder 166 through bellows selector valve 165.As long as outer pin 90 is in a vertical position such that it is capable of engaging slots 112 and 114, wire 140 will be connected to ground through plug 138, plunger 126, outer pin 90, cylinder 82 and table 28, the latter being at ground potential. Ground sensing de- vice 176 senses this condition and causes solenoid valve178 to block fluid pressure from conduit 180 from reaching selector valve 165. This permits reversible valve 154 to remain in the position shown in which air under pressure is supplied to table surface 30 through conduit 168, valve 37 and passageways 36. Should outer pin 90 be de¬ pressed, for example if the fixture 32 were lowered onto table 28 without one of slots 112 or 114 being positioned over pin 90, plunger 126 will be moved out of contact with plug 138 so that ground sensing device 176 would de- tect a no-ground condition. In this case, solenoid valve 178 would admit pressurized fluid from conduit 180 to pilot cylinder 166 which would shift valve 154 to the closed position thereby interrupting the supply of fluid pressure to table 28. It should be noted that even though inner pin 92 may be retracted, outer pin 90 will remain extended unless physically depressed.To illustrate the functioning of the present appara¬ tus, a series of positioning operations will be described. Assume that the fixture 32 has been lowered on the table with one of its slots 112 or 114 aligned with outer pin 90 so that the latter remains extended as shown in Fig¬ ure 9. Pressurized air is then admitted to table 28 through valve 154, conduit 168, valve 137 and passageways 38 so that the fixture 32 floats on a thin film of air above table surface 30. Fixture 32 cannot slide off table 28 due to the fact that pin 90 and slots 112 or 114 remain interengaged, but is free to translate and rotate within the constraints imposed by pin 90 and slots 112 and 114. When fluid under pressure is admitted to working chamber 108 through conduit 172 and fitting 110, innerOM pin 92 will be extended upwardly against the downwardly facing surface 182 of slots 112 and 114. If fixture 32 is moved such that its center hole 124 is positioned di¬ rectly above inner pin 92, pin 92 will automatically ex- tend upwardly into hole 124 and accurately locate fixture 32 for rotation about the rotation center defined by pin 92 and hole 124. Fixture 32 may then be rotated to the desired orientation relative to the tool 26 and pneumatic pressure to table 28 will automatically be interrupted through the action of pilot cylinder 166 thereby causing fixture 32 to come to rest on table 28. At this point, bayonet clamps 80 and 82 may be positioned and activated to securely lock fixture 32 in place for machining as shown in Figure 1. Suppose that it is desired to rotate fixture 32 about another center. Clamps 80 and 82 are released and pneumatic pressure is again applied between the fixture and table stirfaces 48 and 30 thereby causing fixture 32 to again float on a film of pressurized air. Pressure to chamber 108 is exhausted so that spring 102 causes inner pin 92 to be retracted out of center hole 124. Fix¬ ture 32 may then be translated with pin 90 received in slot 114. Assuming that inner pin 92 is again extended by applying fluid pressure to working chamber 108, it will urge against the downwardly facing surface 182 of slot 114 until hole 118, for example, comes into alignment with it at which point it will be extended upwardly. At this point, hole 118 becomes the new rotation center for fix¬ ture 32 as illustrated in Figure 2. As described previ- ously, the fixture 32 is accurately located in each desired machining position by means of locating pins 50 and sockets 62. If desired, only one pair of locating pins and sockets 50, 62 need be actuated because center¬ ing pins 90 and/or 92 can contribute to locating the fixture 32 and locking it against translation and rota¬ tion. While this invention has been described as having a preferred design, it will be understood that it is capable of further modification. This application is, therefore, intended to cover any variations, uses, or adaptations of the invention following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains, and as may be applied to the essential features hereinbefore set forth and fall within the limits of the appended claims. | WHAT IS CLAIMED IS:1. In an apparatus for supporting a member having a table with a horizontal upper surface adapted to sup¬ port a fixture thereon and means for supplying fluid under pressure between said table and the fixture sup¬ ported thereon; a centering pin device comprising: an outer pin mounted within said table and pro¬ jecting above said table upper surface, an inner pin being received within said outer pin for movement along a direction generally normal to said table surface, and means for selectively causing said inner pin to project above said outer pin at a first vertical position and alternatively for causing said inner pin to retract to a second vertical position below said first vertical position.2. The apparatus of Claim 1 wherein said pins are concentric and said inner pin is slidably received within said outer pin. 3. The apparatus of Claim 2 wherein said means for selectively causing said inner pin to project and retract includes a fluid actuated piston.4. The apparatus of Claim 3 wherein said means for selectively causing said inner pin to project and retract includes a spring return means v/hich acts in a reverse direction to said piston to return said inner pin to said first or second position when fluid pressure is removed from said piston.5. The apparatus of Claim 4 wherein said outer pin is slidably received in said table for rectilinear move¬ ment along said direction normal to said table surface and is urged upwardly by said spring return means.6. The apparatus of Claim 2 wherein said outer pin is slidably received in said table for rectilinear ove- ment along said direction normal to said table surface.7. The apparatus of Claim 6 including means for interrupting the supply of fluid under pressure between said table and the fixture supported thereon when said outer pin is depressed below a given vertical height above said table surface. 8. The apparatus of Claim 7 wherein said means for interrupting includes an electrical switch device which is actuated by said outer pin.9. The apparatus of Claim 7 wherein said means for interrupting includes: a plunger slidably received in said outer pin, switch means operatively connected to said means for supplying fluid and including a contact element po¬ sitioned to be activated and deactivated by said plunger, and means for moving said plunger to activate said contact element when said outer pin is in said first vertical position and to deactivate said contact element when said outer pin is in said second vertical position, said switch means including means for causing fluid 'pressure to be supplied by said means for supplying when said contact element is actuated and for causing the fluid pressure to be interrupted when said contact ele¬ ment is deactivated.10. The apparatus of Claim 9 wherein an electrical ground is completed through said plunger when said con¬ tact element is activated.11. The apparatus of Claim 21 wherein said pins are concentric and said rotation pin is slidably received in said translation pin. 12. The apparatus of Claim 11 wherein said trans¬ lation pin is slidably received in said table for axial rectilinear movement and further including means for in¬ terrupting the supply of fluid between said surfaces when said translation pin is depressed to a position be- low said slot. 13. The apparatus of Claim 11 including spring means for urging said translation pin to project above said table surface.14. The apparatus of Claim 21 including a second slot in said fixture intersecting the first mentioned slot and adapted to receive said translation pin means, said second slot having closed ends.15. The apparatus of Claim 14 wherein said hole is located at the intersection of said slots. 16. The method of locating a fixture having a down¬ wardly facing bottom surface, a slot in said bottom sur¬ face and a hole in said slot, in an apparatus having a table with an upwardly facing upper surface for support¬ ing the fixture and a first pin extending upwardly out of the table surface, said method comprising: supporting the fixture on the table with the table and fixture surfaces in facing relationship and with the pin received in the slot, supplying a fluid under pressure between the fixture and the table surfaces to provide substantially friction free support of the fixture on the table, causing a second pin having a smaller diameter than the first pin to project upwardly out of the first pin and urge against the fixture slot, moving the fixture on the table such that the slot slides over the first pin until the second pin en¬ gages the hole in the fixture, rotating the fixture about the second pin to a predetermined position on the table, and causing at least one pair of locating elements on the table and fixture surfaces to interengage so as to lock the fixture in said predetermined position on the table.17. The method of Claim 16 and causing a second pair of locating elements on the table and fixture surface toijUREAlTOMPI interengage.18. The method of Claim 16 wherein the first pin is slidably received in the table and including automatically interrupting the fluid supply between the fixture and table if the first pin is depressed by the fixture.19. The method of Claim 16 and automatically inter¬ rupting the fluid supply between the fixture and table if the first pin is not aligned with the fixture slot when the fixture is placed on the table. 20. An apparatus for use in supporting a workpiece in a machine tool for the machining thereof comprising: a table in the machine having an upwardly facing horizontal surface, a fixture having a downwardly facing lower sur- face resting on the upper surface of said table, said fixture being adapted for having a workpiece mounted thereon, means for supplying fluid under pressure between said surfaces for floatingly supporting said fixture on said table surface to permit substantially friction free movement of said fixture thereon, interengagement means on said.surfaces inter¬ locking said fixture and table for limiting horizontal translational movement of said fixture within predeter- mined limits, said interengagement means including a first element on said table surface adapted to interlock with a second element on said fixture surface, and means for automatically interrupting the supply of fluid under pressure between said surfaces whenever said fixture is supported on said table over said first element without said first and second elements being interlocked.21. An apparatus for use in supporting a workpiece in a machine tool for the machining thereof comprising: a table in the machine having an upwardly facing horizontal surface.'BUOM a fixture having a downwardly facing lower sur¬ face resting on the upper surface of said table, said fixture being adapted for having a workpiece mounted thereon, means for supplying fluid under pressure be¬ tween said surfaces for floatingly supporting said fix¬ ture on said table surface to permit substantially fric¬ tion free movement of said fixture thereon, said fixture surface having a slot therein and a downwardly facing hole in said slot, said slot having closed ends, translation pin means mounted within said table and projecting above said table surface at a first verti¬ cal level, said pin means at said first level being re- ceived within said slot and positioned at a level below said hole, rotation pin means received in said translation pin means for reciprocation along a direction generally normal to the surface of said table, and actuator means.for selectively causing said rotation pin means to extend to a second vertical level above said first level and be received in said hole when said hole is positioned over said rotation pin means.22. The apparatus of Claim 21 including means for selectively retracting said rotation pin out of said hole thereby permitting translation of said fixture over said translation pin.23. The method of Claim 16 wherein said apparatus is a machine tool, said fixture has a workpiece secured thereto, and said table is adapted to support the fix¬ ture in position for machining of the workpiece. | BERGMAN R | BERGMAN R |
WO-1979000163-A1 | 1,979,000,163 | WO | A1 | XX | 19,790,405 | 1,979 | 20,090,507 | new | C08J9 | B32B5, B01F17 | B01F17, B32B5, C08F283, C08J9, C08L61 | C08F 283/00, C08J 9/00L51+L61/06 | PHENOLIC FOAM AND SURFACTANT USEFUL THEREIN | A closed cell phenolic-resin foam material comprising phenolic-resin foam forming reactants, a blowing agent, and a surfactant which is the capped reaction product of an alkoxylated amine and a copolymerizable mixture of dialkyl maleate with N-vinyl-2 pyrrolidone or N-vinyl caprolactam. The alkoxylaled amine (Figure 6) is defined with R<s5>s units which are alkoxylated chains (Figure 7). An integer n (Figure 6) is from 2 to 10 inclusive and the ratio of p:q (Figure 7) is 15:85 to 85:15. | PHENOLIC FOAM AND SURFACTANT USEFUL THEREINDisclosurePhenolic polymers have been known for decades. More recently, there has been increased interest in phenolic polymers which can be formed into cellular materials more commonly referred to as foams. These foams are produced by mixing reactants in the presence of a blowing agent. See for example Thomas et al. U.S. Patent 2,744,875 (1956); . Nelson Canadian Patent 674,181 (1963); Dijkstra Canadian Patent 684,388 (1964); issenfels et al. Canadian Patent 866,876 (1971); United Kingdom Specification 598,642 (1948); Australian Patent 128,508 (1945); and Modern Plastics Encyclopedia Volume 52, No. 10a, page 479 (1977). However, most known cellular materials produced from phenolic polymers exhibit an unsatisfactory thermal con- ductivity initially. Other known cellular materials produced from phenolic polymers exhibit an undesirable increase in thermal conductivity with time.Accordingly, it is an object of the present invention to provide an improved closed cell phenolic- resin foam material substantially free of the disadvan¬ tages of prior foams.Another object is to provide an improved process for producing improved cellular materials employing an improved phenolic -polymer, and an improved laminated building panel employing the improved closed cell phenolic- resin foam material. A still further object is to provide an improved . closed cell phenolic-resin foam material which exhibits a high closed cell content without adversely affecting friability, compressive strength and the low flammability characteristics of the material.Yet another object is to produce a closed cell phenolic-resin foam material with high thermal resistance and high insulation properties and a substantially slow increase in thermal conductivity with time.A further object is to produce a closed cell phenolic-resin foam material which can be used as build¬ ing panels which are highly insulating, thermally resistant, low in friability, soundproof and self-supporting.Additional objects and advantages of the present invention will be apparent to those skilled in the art by reference to the following detailed description and draw¬ ings wherein:Figure I is Formula I;Figure II is Formula II;Figure III is Formula ΪII;Figure IV is Formula IV;Figure V is Formula V;Figure VI is Formula VI;Figure VII is Formula VII;Figure VIII is a cross-sectional view of a laminated building panel having one facing sheet;Figure IX is a cross-sectional view of a laminated building panel having two facing sheets;Figure X is a graph showing the relationship between k-factor and time for foams of the present inven¬ tion.According to the present invention, there is -provided a closed-cell cellular composition comprising a phenolic resin, blowing agent and a surfactant having hydroxyl number of less than 50 preferably less than 10 by reaction with a capping agent. The process of capping functional groups is well known and common agents for mask¬ ing the functionality of the hydroxyl group are agents which produce esters, urethanes, and ethers. Phenolic resin foams are a well known class, phenolaldehyde resin foams being representative and proportions of blowing agent, catalyst and components are well known in the art.Foams of low friability can be obtained by using a preferred phenolic polymer described in Moss U.S. Patent 3,876,620. The preferred polymer of Formula I shown inFigure I of the drawings wherein R is II0CH-, hydrogen,1! 14 R or a radical of Formula II.2 The R 's are independently selected from the group consisting of lower alkyl, phenyl, benzyl, halo, nitro, and hydrogen. The R 's are independently selected from the group consisting of HOCH-, hydrogen or a radicalin Figure II.The R >4.'s are independently selected from the group consisting of lower alkyl, hydrogen, phenyl, benzyl, or furyl. By furyl is meant the radical introduced by the use of furfural. In Formula I, x is an integer from 2 to 10 inclusive and is preferably an integer from 2 to 6 inclusive. When x is less than 2, a foam produced from such a phenolic polymer tends to have too high a friability. On the other hand, as x exceeds 10, the viscosity of the polymer increases to the point where it is difficult to produce the foam. The phenolic poly¬ mers of the present invention generally have a molecular weight between 200 and 2,000 and preferably have a molec¬ ular weight between 300 and 1,500. At lower molecular weights, the resultant foams tend to have too high a friability, whereas at high molecular weights the vis¬ cosity of the phenolic polymer, even when a solvent is present, tends to be too high to permit processing. A preferred subclass of phenolic polymers are those of Formula III, shown in Figure III.In Formula III, R is HOCH -, hydrogen, or a radical of Formula IV.The R 3's are independently selected from the group consisting of IiOCH -, hydrogen, or a radical ofFormula IV, shown in Figure IV.In a preferred. embodiment of the present inven-3 tion, at least one of the R 's is methylol, i.e., IIOCH -.This is to ensure that there will be cross-linking sites on the phenolic polymer. Of course, such methylol groups or, when the aldehyde is other than formaldehyde, alkylol groups, are automatically introduced into the polymer as is well-known in the art by the process described below.In the broadest aspects of the present invention, the phenolic polymer can contain widely varying ratios of the radicals of Formula II or IV to ortho-cresol units. However, this ratio is generally from 1:3 to 10:1 and is preferably from 1:1.5 to 5:1. At higher ratios, i.e., a deficiency of ortho-cresol, • the cellular material pro¬ duced from such a phenolic polymer tends to be too friable. In determining the above ratios, one must include the radicals of Formula II or IV present in Formula I or III respectively. The synthesis of phenolic polymers of Formula I through IV is described and claimed in Moss U.S. Patent 3,876,620. These phenolic compositions use¬ ful in the present invention generally comprise the phe¬ nolic polymer of Formula I or Formula III, together with a compound of Formula V.The compound of Formula V can be present in the phenolic composition in widely varying ratios of Compound V to polymeric composition but is generally present in a weight ratio of 1:30 to 1:2 and is preferably present in a weight ratio of 1:20 to 1:5. Examples of suitable compounds of Formula V include among others: m-cresol, m-chlorophenol,. m-nitrophenol, 3 , 5-xylenol, and phenol, i.e., hydroxy benzene. Phenol is the most preferred compound of Formula V because of cost, availability, and reactivity. The phenolic polymers of Formula I and Formula III are produced according to the present invention by combining certain reactants in a two-step process described in Moss, supra.In the broadest aspects of the present invention, any aldehyde can be employed to produce useful phenolic polymers. Examples of suitable aldehydes include among others furfural, formaldehyde, benzaldehyde, and acetal- dehyde. Formaldehyde is the preferred aldehyde. Formal¬ dehyde can be employed in widely varying forms such as the 37% aqueous solution widely known as formalin. How¬ ever, it is generally necessary to remove from the poly¬ meric material the water introduced with the formalin. Formaldehyde is preferably employed in the form of para- formaldehyde which contains much less water.The cellular material of the present invention is formed by simply reacting the alkylol group containing phenolic polymer of Formula I or Formula III and the compound of Formula V under conditions such that a cellu¬ lar product will result. As is well known in the phenolic foam art, the reaction can be conducted in the presence of a foaming catalyst, a blowing agent, and a surfactant. The reaction can be performed between temperatures of 10-50°C, preferably 15-25°C, and conveniently at atmos¬ pheric pressure. The cellular materials of the present invention generally have a thermal conductivity, k-factor value, of from 0.1 to 0.3 and preferably from 0.1 to 0.2 Btu/hr-°F-sq. ft per inch as measured at 24°C. The k-factor value is measured on a Model 88 machine supplied by the ANACON Company. The friability of the cellular material is 20% or less. Friability is the propensity of the foam to break expressed in percent weight loss. This is determined by the ASTM C-421 friability test conducted for 10 minutc-3. In the broadest aspects of the present invention, any catalyst which will enhance the cross-linking and foaming reaction can be employed in the present invention. However, the preferred foaming catalysts are aromatic sulfonic acids, examples of which include, among others, benzene sulfonic acid, toluene sulfonic acid, xylene sulfonic acid, and phenol sulfonic acid. Phosphoric acid can also be employed either alone or in a mixture with the sulfonic acids. The preferred sulfonic acid is a mixture of equal parts by weight of toluene sulfonic acid and xylene sulfonic acid as described in Mausner et al U.S. 3,458,449. Another foaming catalyst which has been found to give excellent results is a blend of toluene sulfonic acid, phosphoric acid, and water in a weight ratio of 35-50:50-35:15.The catalyst is generally present in the minimum amount that will give the desired cream time of 10 to 50 seconds and firm time of 40 to 500 seconds to the reacting mixture. The catalyst, however, generally comprises from 0.5 to 20, and preferably comprises from 1.0 to 15, weight percent based on the weight of the cellular material.Any blowing agent characteristically employed in similar prior art products such as is described in Moss et al, U.S. Patent 3,968,300, can be employed in the composition of the present invention. In general, these blowing agents are liquids having an atmospheric pressure boiling point between minus 50 and 100°C and preferably between zero and 50°C. The preferred liquids are hydrocarbons or halohydrocarbons. Examples of suitable blowing agents include, among others, chlori¬ nated and fluorinated hydrocarbons such as trichloro- fluoromethane, CC1_FCC1F2, CC1 FCF_, diethyl ether, iso- propyl ether, n-pentane, cyclopentane, and 2-methylbutane. Combinations of trichlorofluoromethane plus 1,1, 2-trichloro,^BΪJ' O 1,2,2-trifluoroethane, are the preferred blowing agents. The blowing agents are employed in an amount sufficient to give the resultant foam the desired bulk density which is generally between 0.5 and 10, and preferably between 1 and 5 pounds per cubic foot. The blowing agent generally comprises from 1 to 30, and preferably comprises from 5 to 20 weight percent of the composition. Khen the blowing agent has a boiling point at or below ambient, it is main¬ tained under pressure until mixed with the other components. Alternatively, it can be maintained at subambient tempera¬ tures until mixed with the other components.In the broadest aspects of the instant invention, any hydroxyl containing cell stabilizing surfactant with a branched, non-ionic structure conventionally used in producing polymeric foams can successfully be used after capping the hydroxyl groups. By cell stabilizing sur¬ factant is meant one which keeps a foam from collapsing and rupturing. Typical surfactants have hydroxyl numbers in the range of 60 to 100. In other, words, any branched conventional surfactant whose hydroxyl number is reduced to a value of less than 50, preferably less than 10, by reaction with a suitable capping agent such as organic acid, acid anhydride, acid chloride, acyloxy chloride and alkyl or aryl isocyanate is a suitable surfactant. Alcohols can be converted to ethers but this generally does not result in a surfactant that behaves as a cell stabilizer. The hydroxyl number is determined by the ASTM-D1638 test.The preferred surfactant is the capped reaction product of an alkoxylated amine of Formula VI shown as5 Figure 6 wherein R is an alkoxylated chain of FormulaVII, n is an integer from 2 to 10 inclusive and the ratio p:q is 15:85 to 85:15, which amine has been reacted with a copolymerizable mixture of dialkyl maleate and a member selected from the group consisting of N-vinyl-2-pyrroli- done and U-vinyl caprolactam, the alkyl of the maleate having 1 to 5 carbon atoms. The preferred dialkyl maleate is dibutyl maleate.The alkoxylation is carried out using a mixture of ethylene oxide and propylcne oxide in a ratio of 15:85 to 85:15 and preferably from 20:80 to 60:40. The molecular weight of the alkoxylated amine is from 1500 to 6000 and preferably from 1800 to 2800. If the molecular weight of the alkoxylated amine is less than 1500, the resultant foam collapses. An alkoxylated amine of molecular weight higher than 6000 is too viscous to be practicable.The preferred molar ratio of dibutyl maleate and N-vinyl-2-pyrrolidone is 1:1, the mixture of dibutyl maleate and N-vinyl-2-pyrrolidone comprising between 5 and 40 weight percent of the reaction mixture, and pref¬ erably 20 weight percent of the reaction mixture. If less than 5 percent is used, the surfactant is ineffective, if more than 40 percent is used, the foam collapses. N-vinyl- 2-pyrrolidone and N-vinyl caprolactam are interchangeable in equivalent quantities, but N-vinyl-2-pyrrolidone is * preferred.The capping reaction is carried out with a capping agent. Suitable capping agents include a lower alkyl monocarboxylic acid having 1 to 10 carbon atoms selected from the group consisting of acetic acid, pro- pionic acid, butyric acid, hexαnoic acid, octanoic acid, decanoic acid, isomers of these acids, anhydrides of these acids, acid chloride derivatives of these acids and mix¬ tures thereof. Acetic anhydride is readily obtainable and convenient to use. Similarly aromatic acids, anhydrides and chlorides can be employed. Benzoyl chloride and substituted produces of it such as 3,5-dinitrobenzoyl chloride are examples of these. Alkyl and aromatic iso- cyanates can also be employed. Other factors such as solubility in the surfactant and the solubility of the capped- surfactant with a particular phenolic-resin are considerations of which a practitioner in the art is cognizant in selecting the system which will yield the desired closed cell stabilized foam. Examples of suitable capping agents are acetic acid, acetic anhydride, acetyl chloride and 3,5-dinitrobenzoyl chloride, reacted so that the surfactant has a hydroxyl value of less than 50, and preferably less than 10. The preferred capping agent is acetic anhydride.The preferred surfactants useful in the present invention produce a uniform fine-celled foam. Uniformity of cells is determined by visual and microscopic exami¬ nation. The surfactants must produce a fine celled foam. This property is tested by mixing 2 to 5% of the surfac¬ tant with the phenolic composition and producing a foam as described herein. It is interesting to note that a low surface tension of the surfactant in the phenolic- resin is not a prerequisite to obtaining a good foam.The average cell size diameter must be less than.0.2 mm and is preferably less than 0.1 mm (ASTM D-2842) . Fine celled foams can be the means set forth in the invention be rendered closed -cells. The blowing agent is then trapped in the cells. One means of expres¬ sing the containment in the cells of the blowing agent is by use of the k-factor drift value. Unfaced cellular materials containing fluorocarbon gas have initial k- factors in the vicinity of 0.1-0.2 at 24°C. This low value increases over a period of months or sometimes days. The change is expressed as the k-factor drift. The k-factor is measured at a mean temperature of 24°C. The value is redetermined at various time intervals up to about 1000 days. A material exhibiting fast k-drift will attain2 a k-factor (Btu/hr-°F-ft per inch thickness) of at least0.2 within 25 days. A slow k-drift material may require between 200 days and over two years to attain a 0.2 value.Any material which possesses a k-value under 0.2 will provide high thermal resistance. Obviously, the longer this value or a lower value is maintained, the better the efficiency of the insulation.Ball, Kurd and Walker have published a com¬ prehensive discussion of k-factor changes as a function of time. ( The Thermal Conductivity of Rigid Urethane Foams, J. Cellular Plastics, March/April, 1970, pp 66-78.) F. Norton ( Thermal Conductivity and Life of Polymer Foams, J. Cellular Plastics, January, 1967, pp 23-37) has shown that diffusion of fluorocarbon gases out of unfaced foam and infusion of air into the foam causes an increase in k-factor. A slow k-drift foam is defined as one that attains a k-factor ; at 24°C of 0.15-0.17 after 200-400 days and then remains below 0.2 k-factor for 5-10 years. Eventually all fluorocarbon diffuses from, the foam to leave a closed cell material which contains only air in the cells.The k-factor for the closed cell foam containing only air falls in the range of 0.22-0.26 Btu/hr-°F-ft2 per inch thickness at 24°C for the 2-3 lbs/ft density range. Therefore, if a foam exhibits greater than 0.2 k-factor after a short period of time (less than 25 days) , then substantially all fluorocarbon has diffused from the foam and has been replaced by air. On the other hand, if k-factor remains below 0.2 for at least 100 days then a substantial amount of fluorocarbon gas remains in the closed cells of the foam in spite of infusion °f air.It has been found that capping the surfactant that yields a fine celled foam increases the closed cell content and the initial k-factor is lowered.Moreover, capping and grafting the surfactant yield a fine celled foam with high closed cell content, a low initial k-factor and a low k-drift value.The surfactant is employed in a cell stabilizing amount. Generally the surfactant comprises from 0.05 to 10, and preferably, comprises from 0.1 to 6, weight percent of the composition. Too little surfactant fails to stabilize the foam and too much surfactant is not only wasteful, but also for surfactants having relatively high surface tension (about 35 dynes/cm) may lead to larger cell structure by cell coalescence and the foam may collapse. Branched, non-ionic, capped, grafted sur¬ factants are preferred.As used herein any of the alkyl, aryl, aralkyl, and/or alkaryl groups can be substituted with one or more groups that do not. materially affect the physical or chemical properties of the surfactant compound. Examples of substituents include, among others, -F, -Cl, -Br, -CH3, and -N02.Referring now to the drawings, and in particular to Figure VIII, there is shown a laminated building panel 10 of the present invention. The building panel 10 com¬ prises a single facing sheet 11 having thereon a cellular material 12 of the present invention. Figure IX shows a building panel 20 having two facing. sheets 21 and 22 on either. side of a cellular material 23.Any facing sheet previously employed to produce building panels can be employed in the present invention. Examples of suitable facing sheets include, among others, those of kraft paper, aluminum, and asphalt impregnated felts, as well as laminates of two or more of the above.The invention is further illustrated by the following.examples in which all parts and percentages are by weight unless otherwise indicated. These non-limiting examples are illustrative of certain embodiments designed to teach those skilled in the art how to practice the invention and to represent the best mode contemplated for carrying out the invention. Example 1This example illustrates the synthesis of a phenolic polymer of Formula I useful in the present invention employing a molar ratio of phenol to o-cresol of 2:1.AmountItem Ingredient grams molesA o-cresol 10,580 98B paraformaldehyde (93.6%) ■4,743 148C, sodium hydroxide (50%) 295 3.69D phenol 18,428 196E paraformaldehyde 7,917 247F glacial acetic acid 225 3.75Items Λ and B are charged to a reaction vessel. Item C is added over a period of fifteen minutes, the temperature rises to 100°-C due to an exothermic reaction x and is maintained at that level for 1 hour. Items D and E are then added and the temperature maintained at 80°C for four and one-half hours. Item F' is then added and the contents of the reaction are termed Resin B.Resin B has a viscosity at 25°C of 29-,500 cps, a free phenol content of 8.1%, and a free water content of 9.1%, a free formaldehyde content of 0.6%, and a free o-cresol content of less than 0.1%. Example 2This example illustrates the synthesis of a phenolic polymer of Formula I useful in the present invention employing a molar ratio of phenol to ortho- cresol of 4:1.The following quantities of the following ingredients are combined as indicated.Amount Item Ingredient grams molesA o-cresol. 6,901 63.9B paraformaldehyde (93.5% HCHO) 3,133 97.7 C sodium hydroxide (50% NaOH) 215 2.69 D phenol - 24,025 255.5E paraformaldehyde 11,350 354.1F sodium hydroxide (50% NaOH) 215 2.69 G glacial acetic acid 350 . 5.8Items A and B are charged to a reaction vessel. Item C is added over a period of fifteen minutes, the temperature rises due to the exothermic reaction, to 100°C and is maintained at that level for 1.5 hours. Items D, E, and F are then added and temperature maintained at 80°C for 5 hours. Item G is then added and the contents of the reaction vessel is termed Resin C.Resin C has a viscosity at 25°C of 24,300 cps, a free phenol content of 8.6%, and a free water content of 10.0%, a free formaldehyde content of 2.3%, and a free o-cresol content of less than 0.1%. BUREAU OMPI WIP0 - Example 3This example illustrates the synthesis of a surfactant precursor.AmountItem Ingredient grams molesA ethoxylated propoxylated ethyleennee diamine (Tetronic 704) 800 (0.31)*B N-vinyl-2-pyrrolidone 64 0.577C dibutyl maleate 136 0.596D azo-bis-isobutyronitrile 4.0 0.02439E t-butylperbenzoate 2.0 0.01031Item A is placed is a reaction vessel at 90°C. Item B is placed in a dropping funnel. Items C, D, and E are mixed together and placed in a second dropping funnel. The contents of the two dropping funnels are each concurrently added to the reaction vessel. over a period of one hour while maintaining the temperature at 90°C. The temperature is raised to 140°C for an additional hour to produce a surfactant precursor.Item A has a molecular weight of 2600, has a weight ratio of ethylene oxide to propylene oxide of 40:60, and is available from the BASF Wyandotte Corporation, Wyandotte, Michigan, U.S.A., under the tradename TETRONIC 704. * JWRC Progress Report, Project No. 05-01-03-09, Page 12 7.28 x 10 mmoolleess OOHH//gg.. = (0.5824 moles OH)P. 12 last line Example 4This example illustrates the capping of sur¬ factants useful in the present invention.Amount Item Ingredient grams molesA surfactant precursor from Example 3 400 0.154B acetic anhydride 30 0.294Items A and B are mixed together at room temperature and heated to 100°C for two hours to produce a surfactant useful in the present invention termed Surfactant A. Example 5 This example illustrates the synthesis of foam¬ ing catalysts useful in the present invention.The following quantities of the following ingredients are combined as indicated to produce Catalyst A:Ingredients QuantitItem Name gramsA p-toluene sulfonic acid 333 B xylene sulfonic acids 333 C water 333 Items A, B, and C are mixed. The resultant composition is termed Catalyst A.The following quantities of the following ingred¬ ients are combined as indicated to produce Catalyst B: Ingredients QuantityItem Name gramsA Ultra TX 667B water * 333Items A and B are mixed. The resultant com¬ position is termed Catalyst B. Ultra TX is a mixture of equal parts by weight of p-toluene sulfonic acid and xylene sulfonic acids available from the Witco Chemical Compa y. Example 6This example illustrates the synthesis of a foam based on 2:1 phenol:o-cresol resoles of the present invention.Item Ingredient 9:aJEA Resin B 300B CFC13 22.5C CCl-FCF Cl 22.5D Surfactant A of Example 4 15E Catalyst B 40Items A through E are mixed in an open vessel for 15 seconds. The mixture is then poured into a square paper box twelve inches by twelve inches by five inches tall. A foaming reaction ensues. After a period of about 240-300 seconds the material is rigid. The box and con¬ tents are placed in an oven at 55° to 75°C for a period of ten minutes to one hour. Exar ples 7-12The procedure of Example 6 is repeated using different surfactants. The characteristics of the sur¬ factant and the resultant foam are shown in Table I.The TETRONIC series of alkoxylated amines are available from BASF Wyandotte Corp., Wyandotte, Michigan 48192.Compressive strength is measured according to ASTM D-1621.Oxygen Index Value is measured according to ASTM D-2863-74.A typical resultant foam has the following properties:Density 2.4 lbs/ft2Thermal Conductivity 0.120 BTU/hr-°F-ft per inchFriability 12%Compressive Strength 30 psiOxygen Index Value 34Figure X shows a plot of k**-factor versus log time. The k-values are plotted on the y-axis (linear scale) and the time in days is plotted on the x-axis (log scale) as described by Ball, Hurd and Walker, supra.Fast k-drift materials attain greater than 0.2 k-factors rapidly as shown by curve 1 which are typically represented by Example 8 of Table I. After the k-factor reaches a value of 0.22 the rate of increase slows, tan- gentially approaching about 0.26.Slow k-drift materials attain less than 0.2 k-values at 1000 days as shown by curve 2 in Figure X, which are typically represented by Example 6 of Table I.It is to be emphasized that these k-values are for 1 thick unfaced (unlaminated) foam boards. Laminated products have superior properties dependent on the permea¬ bility of the laminating material and the total surface- exposed edge proportions. BUO Example 13.This example illustrates the synthesis of a foam based on 4:1 phenol:o-cresol resole of the present invention.Item Ingredient gramsA Resin C 300B CFC13 22.5C CFC1 CF Cl 22.5D Surfactant A of Example 4 15E Catalyst B 35Items A through E are mixed in an open vessel for 15-20 seconds. The mixture is then poured into a square paper box twelve inches by twelve inches by five inches tall. A foaming reaction ensues. After a period of 300-400 seconds the material is rigid. The box and contents are placed in an oven at 55° to 75°C for a period of ten minutes to one hour.Examples 14-16The procedure of Example 6 is repeated using different surfactants. The characteristics of the sur¬ factant and resultant foam are shown in Table II.A typical resultant foam has the following pro¬ perties:Density 2.2 lbs/ftThermal Conductivity 0.13 Btu/hr-°F-ft per inchFriability 32% Compressive Strength 25 psi Oxygen Index Value 40 BU EAU OMPI P TABLE IPROPERTIES OF PHENOLIC FOAMS MADE WITH 2:1 PHENOL:O-CRESOL BASED RESINSCopolymerExample Alkoxylal bed Level Ratio (No.) Amine ( t.ϊ,) RiS.6 Tetronic 704 20. 40:607 Tetronic 702 20 20:808 Tetronic 504 20 40:609 Tetronic 702 30 20:8010 Tetronic 704 30 40:6011 Tetronic 702 10 20:8012 Tetronic 704 10 40:60 -21- ABLE I (cont)PROPERTIES OF PHENOLIC FOAJ-iS HADE WITH 2:1 PHENOL:O-CRESOL BASED RESINSk driftInitial k eiKExample Density (Btu/hr-βF- dLogt .(No.) (lb/ftJ) ft2 per inch ■ i (x iθ3)•6 2.4 0.120 67 2.3 0.128 ' 58 2.3 * 309 2.3 0.128 910 2 .7 0.128 911 2.6 0.13 2412 2.6 0.128 9r0.44 on p. 34 of JWRC report TABLE IIPROPERTIES OF PHENOLIC FOAMS MADE WITH 4 : 1 PHENOL : 0-CRESOL BASED RESINSCopolymerExample Alkoxylated Level Ratio (Wo..) Amine (Wt.-l) Eϋ.14 Tetronic 704 20 40:6015 Tetronic 704 20 40:6016 Tetronic 702 ' 20 20:80 BUO TABLE II (cont)PROPERTIES OF PHENOLIC FOAMS MADE WITH 4:1 PHENOL:0-CRESOL BASED RESINSk driftI.nitial k •dx Example Density ' (Btu/hr-°F- dLoσt Ciatalyst B ■(Wo.) (Ib/ft3)_ ft2 per inch) (x 103) phr14 2.2 0.13 9 11.715 2.3 0.13 5 13.316 2.3 0.12 5 11.7 BUREAUO PI Although the invention has been described in considerable detail with reference to certain preferred embodiments thereof/ it will be understood that varia¬ tions and modifications can be effected within the spirit and scope of the invention as described above and as defined in the appended claims. | What is claimed is:1. A closed cell foam material comprising the reaction product of:A. phenolic-resin foam forming reactants,B. a blov/ing agent,C. a surfactant which is the capped reaction product of:I. an alkoxylated amine of FormulaVI wherein:(a) R_ is an alkoxylated chain of Formula VII,(b) n is an integer from 2 to 10 inclusive,(c) the ratio p:q is 15:85 to 85:15 withII. a copolymerizable mixture of dialkyl maleate and a member selected from the group con¬ sisting of N-vinyl-2-pyrrolidone and N-vinyl caprolactam.2. The closed cell foam material of Claim 1 wherein the phenolic resin foam forming reactants comprise phenol and an ortho-cresol-phenol block copolymer.3. The closed cell foam material of Claim 2 wherein the ratio of phenol to ortho-cresol in the phenolic resin is 1:1.5 to 10:1.4. The closed cell foam material of Claim 1 wherein the surfactant is capped with acetic anhydride.5. The closed cell foam material of Claim 1 wherein the surfactant has a hydroxyl value of less than 50. 6. The closed cell foam material of Claim 1 wherein the blowing agent is present in an amount sufficient* to give the resultant foam a density of 0.5 to 10 pounds per cubic foot.7. The closed cell foam material of Claim 1 wherein the blowing agent comprises 1 to 30 weight percent of the foam material.8. The closed cell foam material of Claim 1 wherein the surfactant comprises from 0.05 to 10 weight percent of the foam material.9. The closed cell foam material of Claim 1 wherein the alkoxylated amine has a molecular weight between 1500 and 6000.10. The closed cell foam material of Claim 1 wherein the copolymerizable mixture comprises 5 to 40 weight percent based on the weight of the capped reaction product.11. The closed cell foam material of Claim 1 wherein the alkyl of the dialkyl maleate has 1 to 5 carbon atoms. 12. A closed cell foam material of Claim 1 comprising the reaction product of:A. an alkylol group containing phenolic polymer of Formula I wherein:(a) R is H0CH-, hydrogen, or a radical of Formula II,2(b) the R 's are independently selected from the group consisting of lower alkyl, phenyl, benzyl, halo, nitro and hydrogen,(c) the R 's are independently selected from the group consisting of H0CH-, hydrogen, and a radical of Formula II, R44(d) The R 's are independently selected from the cjroup consisting of lower alkyl, hydrogen, phenyl, benzyl, and furyl,(e) x is an integer from 2 to 10 inclusive,(f) the phenolic polymer has a molec¬ ular weight between 200 and 2000,B. a compound of Formula V wherein the weight ration of B:A is 1:30 to 1:2,C. a blowing agent in a minor amount sufficient to foam the reaction mixture, andD. a surfactant which is the reaction product ofI. an alkoxylated amine of FormulaVI v/herein:(a) R5 is an alkoxylated chain of Formula. VII,(b) n is an integer from 2 to10 inclusive,(c) the ratio p:q is 15:85 to85:15,(d) the molecular weight of the alkoxylated amine is 1500 to 6000, and II. a copolymerizable mixture of dialkyl maleate and a member selected from the group consisting of N-vinyl-2-pyrrolidone and N-vinyl capro- . lactam,III. a capping agent selected from the group consisting of acetic acid, acetic anhydride, acetyl chloride, and 3,5-dinitrobenzoyl chloride, so that the surfactant has a hydroxyl value less than 10. 13. A closed cell foam material of Claim 1 comprising the reaction product of:A. a methylol group containing phenolic polymer of Formula III wherein:(a) R is HOCH2~, hydrogen or a radical of Formula IV,(b) the R 's are independently selected from the group consisting of HOCH -, hydrogen and a radical of Formula IV,(c) x is an integer from 3 to 6 inclusive,(d) the phenolic polymer has a molec¬ ular weight between 300 and 1500,B. phenol, wherein the weight ratio of B:A is 1:20 to 1:5,C. a blowing agent in a minor amount sufficient to foam the reaction mixture,D. a surfactant which is the reaction product of:'I. an alkoxylated amine of Formula VI wherein:(a) R is an alkoxylated chain of Formula VII,(b) n is an integer from 2 to 10 inclusive,(c) the ratio p:q is 20:80 to 60:40,(d) the molecular weight of the alkoxylated amine is 1800 to 2800,II. a copolymerizable mixture of dibutyl maleate and N-vinyl-2-pyrrolidone wherein the copolymerizable mixture comprises 20 weight percent based on the v/eight of the reaction product, and the molar ratio of dibutyl maleate to N-vinyl-2-pyrrolidone is 1:1,III. acetic anhydride, wherein the surfactant has a hydroxyl value less than 10. -3tf-14. A process for producing a closed cell foam material, said process comprising reacting phenolic-resin foam forming reactants in the presence of a blowing agent and a surfactant which is the capped reaction product of:I. an alkoxylated chain of Formula VI wherein:(a) R-*- is an alkoxylated chain ofFormula VII,(b) n is an integer from 2 to ,10 inclusive,(c) the ratio p:q is 15:85 to 85:15 withII. a copolymerizable mixture of dialkyl maleate and a member selected from the group consisting of N-vinyl-2-pyrrolidone and N-vinyl caprolactam.15. A process for producing a closed cell foam material, said process comprising reacting phenolic-resin foam forming reactants in the presence of a blowing agent and a surfactant which is the reaction product of:I. an alkoxylated amine of Formula VI wherein:(a) R is an alkoxylated chain ofFormula VII,(b) n is an integer from 2 to 10 inclusive,(c) the ratio p:q is 20:80 to 60:40,(d) the molecular weight of the alkoxylated amine is 1800 to 2800,II. a copolymerizable mixture of dibutyl maleate and N-vinyl-2-pyrrolidone wherein the copoly¬ merizable mixture comprises 20 weight percent based on the weight of the reaction product, and the molar ratio of dibutyl maleate to N-vinyl-2-pyrrolidone is 1:1,III. acetic anhydride, wherein the surfactant has a hydroxyl value less than 10. 16. A laminated structural panel having at least one facing sheet and having the closed cell foam material of Claim 1 adhering to it.17. A surfactant which is the capped reaction product of:I. an alkoxylated amine of FormulaVI wherein:(a) R**-5 is an alkoxylated chain of Formula VII,(b) n is an integer from 2 to 10 inclusive,(c) the ratio p:q is 15:85 to 85:15 withII. a copolymerizable mixture of dialkyl maleate and a member selected from the group consisting of N-vinyl-2-pyrrolidone and N-vinyl caprolactam.18. A surfactant which is the reaction product of:I. an alkoxylated amine of Formula VI wherein:(a) R is an alkoxylated chain of Formula VII,(b) n is an integer from 2 to 10 inclusive,(c) the ratio p:q is 20:80 to 60:40,(d) the molecular weight of the alkoxylated amine is 1800 to 2800,II. a copolymerizable mixture of dibutyl maleate and N-vinyl-2-pyrrolidone wherein the copoly¬ merizable mixture comprises 20 weight percent based on the weight of the reaction product, and the molar ratio of dibutyl maleate to N-vinyl-2-pyrrolidone is 1:1,III. acetic anhydride, wherein the surfactant has a hydroxyl value less than 10.. sAι wipo - | CELOTEX CORP | BEALE J; MOSS E |
WO-1979000164-A1 | 1,979,000,164 | WO | A1 | XX | 19,790,405 | 1,979 | 20,090,507 | new | B65D27 | B65D27 | B65D27 | B65D 27/04, B65D 27/06 | REVERSIBLE ENVELOPE | A blank for a returnable envelope has a main panel (4) with a window (18) and end (16) and side flaps (10, 14). One of the side flaps (10) has a return address (24) on one face of the blank and releasable adhesive (22) on the other face along the outer edge. The other side flap (14) has a moisture activatable adhesive (30) along its outer edge (28) and end edges (26) on the same face of the blank as the return address. The blank can be folded to form an envelope, stuffed with an enclosure and releasably sealed, all by automatic machinery, then opened without tearing or severing any part and reversely folded and sealed for return mailing with the return address visible through the window. | REVERSIBLE ENVELOPEBACKGROUND OF THE INVENTIONThis invention is in the field of stationery and particularly remailable envelopes. The concept of providing an envelope that can be closed and mailed and one whereby the receiver may then open the envelope to obtain its contents and use the same envelope for a return mailing is old and many attempts have been made to provide a satisfactory envelope capable of such use. It is desirable to be able to use the same envelope for return mailing to conserve paper, which becomes an expensive item where a great number of mailing are made from, for example, business establishments in billing their customers. It is further desirable that the first mailings be capable of being- handled, that is, formed into an envelope stuffed with an enclosure and closed for mailing all by automatic machinery. It is further desirable that such mailings be capable of being reused for return to the sender. An example of a returnable envelope is shown in the patent to Harvey No. 877,330 where the main panel of his envelope is provided with interlocking end flaps and a top and bottom flap. For the first mailing the bottom flap is folded up over the end flaps, then the top flap is folded downwardly and adhered to the bottom flap by adhesive provided on one face of the envelope material. The bottom flap is provided with adhesive material on the other face of the sheet so that it underlies the top flap when the latter is sealed for the first mailing. The recipient opens the letter by severing the top flap along the edge of the adhesive material and the envelope can then be used for remailing by reversible folding of all flaps against the other face of the sheet material and the bottom flap then is folded last and its adhesive material used to seal the envelope. In both the first and second mailings, however, the adhesive is permanent and the flap must be actually severed to provide access to the contents thus leaving its severed edge inside the remailed envelope.SUMMARY OF THE INVENTIONThe present invention relates to a blank for an envelope capable of being handled entirely by automatic machinery and yet which can be reused for return mailing without ever severing or separating any portions of the blank. In general, the invention relates to a business envelope having a window therein and the sender's return address printed on a flap which address appears on the outside of the envelope for the first mailing but when the blank is reversed for return mailing, the address appears in the window as the address to which it is then to be sent. For the first mailing the envelope is closed by releasable adhesive means which may be a row of small spots of adhesive or a pressure sensitive adhesive that may be readily released without tearing the material of the envelope.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a view of a blank for forming an envelope showing one face thereof; andFIG. 2 is a view of the other face of the blank of FIG. 1.DESCRIPTION OF THE PREFERRED EMBODIMENTIn the drawings, numeral 2 designates generally a blank of sheet material, such as paper, defining a rectangular main panel 4 having end flaps 6 extending from its ends and being integrally joined thereto along fold lines 8. The lines 8 may be score lines to facilitate folding but such score lines are not essential. An integral top flap 10 is foldabl , joined to the upper edge of the main panel 4 along a fold line 12 and an integral bottom flap 14 is foldably joined to the lower edge of the main panel along a fold line 16. The main panel 4 is also provided with a window opening 18 therein. The window 18 may be a transparent portion of the sheet from which the blank is formed. Such windows are well known and need not be further described.The upper flap 10 is provided, along its free edge 20 with a row of relatively small spots 22 of a readily releasable adhesive material. Many such ' materials are known and need not be described in greater detail except to point out that they may be in the nature of a more or less permanent or moisture activatable adhesive or they may be in the nature of a pressure sensitive adhesive material. As shown in FIG. 2, the upper flap 10 is provided on the face opposite the face appearing in FIG. 1 with a return address indicated at 24. The return address is so positioned on the flap 10 that when the latter is folded downwardly over the upper face of the upper panel, as seen in FIG. 2, that address will be visible through the window 18. As also shown in FIG. 2, the lower flap 14 is preferably of a truncated triangular shape having slanted end edges 26 and an outer or free edge 28. On that face of the blank appearing uppermost in FIG. 2, the flap 14 is provided with a row of adhesive material 30 extending along its free edge 28 and at least part way along the end edges 26. It is to be noted that the adhesive 30 is on the opposite face of the blank from the adhesive materials 22 previously referred to. The adhesive 30 may be and preferably is a permanent type of adhesive, for example, a moisture activatable adhesive of well known type.As also shown in the drawings, the face of flap 14 shown uppermost in FIG. 1 is provided with a plurality of spots 31 of a releasable adhesive of the type previously referred to. Also, the other side of end flaps 6, as seen in FIG. 1, which is the upper side of those flaps, as seen in FIG. 2, is shown as also being provided with a plurality of spots of readily releasable adhesive 31. The spots 31 on flap 14 and those on end flaps 6 are positioned so that when the flap 14 overlies a flap 6 the adhesive on one will ' engage the face of the other. It is to be understood, however, that the adhesive on the end flaps may be omitted and only that on flap 14 employed or on the other hand the adhesive may be omitted from flap 14 and only those spots on end flaps 6 being employed, all for the purpose to be described later. It will be further seen from the drawings that the upper edges of the end flaps 6, that is, those edges opposite the fold line 16 and adjacent fold line 12 are so configured that when those flaps are folded inwardly over the main panel 4, an elongated portion of the latter adjacent the fold line 12 is exposed above the upper edges of the end flaps. The lower flap 14 is so dimensioned that the distance between fold line 16 and outer edge 28 is no greater than the distance between fold lines 12 and 16 and yet great enough so that the adhesive 30 along the edge 28 will lie between the upper edges of end flaps 6 and the fold line 12. It is further to be noted that the end flaps 6 are provided with a stepped region 32 along their upper edges and when those end flaps are folded inwardly over the main panel 4, the upper edges of the steps 32 coincide with the end portions of edge 28 and the ends of edge 28 coincide with points 34 at the inner ends of the stepped regions 32 on the upper edges of the end flaps. As stated previously, the blank disclosed and claimed herein is particularly well adapted for handling by automatic machinery. For example, the blank as shown in the drawings may be formed and handled by automatic machinery and further processed by such machinery by folding the end flaps 6 upward and inwardly, as seen in FIG. 1, to overlie panel 4. Then, lower flap 14 can be folded forwardly and upwardly to overlie the flaps 6 and the releasable■BUREAlT_ OMPI •.A*. WIPO adhesive spots 31 caused to hold the flap 14 to the end flaps 6 to form an envelope. It is to be noted that the end portions of the edge 28 of flap 14 will coincide with the upper surfaces of the steps 32, thus defining a more or less continuous upper edge for the envelope which will facilitate automatic or machine stuffing of enclosures into the envelope.The envelopes thus formed may be supplied to the purchaser in bulk and are in condition to be easily stuffed with a suitable enclosure, all by automatic machinery. Machines for inserting enclosures into envelopes are well known and need not be described. The enclosure placed in the envelope should include an address portion positioned to be visible through the window 18 and thereafter the upper flap 10 is folded downwardly and its releasable adhesive spots 22 then engage and adhere to the outer surface of flap 14 on the back of the envelope. The filled and closed envelope is then ready for its first mailing. When the customer receives the envelope containing the described enclosure, the same may be easily opened by merely lifting the flap 10 from flap 14 and thus parting or releasing the adhesive 22 and lifting flap 14 by separating the releasable adhesive 31 without tearing or severing any part of the blank whereupon the envelope may be readily unfolded to the position shown in FIG. 1. The customer may then remove the enclosure. Assuming that the enclosure is a monthly bill, the customer may then prepare his remittance and prepare the envelope for remailing. To remail the envelope-the blank is turned over from the position of FIG. 1 to the position of FIG. 2 and the top flap 10 is first folded down¬ wardly to overlie the main panel whereby the return address becomes visible through window 18 and becomes the address to which the envelope is to be remailed. The customer then places his check or other enclosure over that flap, then fold the end flaps upwardly and inwardly to overlie his enclosure. As will be obvious, after the end flaps 6 are folded inwardly as described, that portion of the upper surface of flap 10 adjacent the fold line 12 will be exposed whereupon the adhesive 30 on lower flap 14 may be moistened or otherwise treated and the flap folded to overlie the end flaps 6 whereupon the adhesive 30 along edge 28 may be adhered to the exposed portion of flap 10 and the portions of the adhesive along edges 26 engage and adhere to the end flaps 6, thus forming a securely sealed envelope for remailing. While a single specific form of the invention has been shown, it is to be understood that other forms may be devised falling within the scope of the invention as defined by the appended claims. | I claim:1. A blank for forming a reversible and returnable envelope, comprising: a sheet of material defining a main panel of generally rectangular shape; an end flap foldably joined to each end of said main panel; a first flap foldably joined to one side edge of said main panel; a second flap foldably joined to the other side edge of said main panel; the outer edge portion of said first flap having means thereon on one face of said blank for releasably securing said first flap to said second flap, the outer edge portion of said second flap having adhesive extending therealong on the other face of said blank; said main panel having a window therethrough; and said first flap having a space for a return address thereon, on said other face of said blank in position to appear through said window when said first flap is folded to overlie said main \ panel on said other face of said blank.•B 2. A blank as defined in claim 1 wherein the upper edges of said end flaps are so configured that, when folded over said main panel, they leave exposed a portion of said main panel adjacent said one side edge of said main panel and the width of said second flap being such that, when folded over said end flaps, said moisture activatable adhesive lies between said upper edges of said end flaps and the adjacent edge of said main panel.3. A blank as defined in claim 2 wherein said moisture activatable adhesive extends also along at least portions of end edges of said second flap.4. A blank as described in claim 1 wherein said releasable adhesive means is a pressure sensitive adhesive.5. A blank as defined in claim 1 wherein said releasable adhesive means comprises a plurality of spots of adhesive material.6. A blank as defined in claim 1 wherein said further releasable adhesive means comprises at least one spot of adhesive material on said second flap on said one face of said blank.7. A blank as defined in claim 1 wherein said further releasable adhesive means comprises at least one spot of adhesive material on said end flaps on said other face of said blank.8. A blank as defined in claim 1 wherein said end flaps are configured to have upper edge portions coincident with the outer edge portions of said second flap when said second and end flaps overlie said main panel.-BU REA UO PI λ , W1P0 A | YALE R | YALE R |
WO-1979000173-A1 | 1,979,000,173 | WO | A1 | XX | 19,790,405 | 1,979 | 20,090,507 | new | G02B3 | null | F24J2, G02B3, G02B5 | F24J 2/08B, G02B 3/08, G02B 5/04A | LENTICULATED LENS | A lens (10) based on the concentration of electro-magnetic radiation through combined reflective and refractive properties of the lens (10). In one form of the lenticulated lens (10), radiation impinges and is transmitted through a substantially planar frontal surface (18). The incident radiation subsequent to being transmitted through the frontal surface (18) impinges on a rear inclined surface (26) forming a portion of the lenticulated rear surface (20) of the lens (10). The ray is reflected from the mirror coated inclined surface (26) and is egressed from the frontal surface (18) and is refracted to a focus line (F). The incident rays (12) impinging on the frontal surface (18) are thus directed to the linear focus line (F) when the lenticulations of the lens (10) are linearly directed. By providing refraction and reflection passage of the incident rays (12) from and through the lens (10), the reflected portion of the incident ray (12) which is focused to a line focus (F) is maximized. | LENTICULATED LENSBACKGROUND OF THE INVENTIONFIELD OF THE INVENTIONThis invention relates to the field of electro-mag¬ netic radiation concentrating systems. In particular, this invention pertins to the field of lenses. Still further, this invention relates to the field of refract¬ ing mirror type lenses. More in particular, this in¬ vention relates to the field of Fresnel type lenses modified to provide both refraction and reflection of incident radiation impinging on the lens. PRIOR ARTMulti-lenticulated lenses are known 'in the art. Additionally, Fresnel type lenses for producing either a line focus or a point focus are also known in the prior art. However, Fresnel type lenses when utilizing linear lenticulations have been provided as reflecting surfaces. In such prior art lenses, the inclined surfaces facing the source of the incident radiation have been mirror coated to provide a direct reflection mode of the radia¬ tion to either a point focus or a line focus. In such prior art lenses, the reflected radiation has been inter¬ fered with by successive lenticulation walls thus reducing the amount of reflected energy which is either directed to the line or point focus. This has caused a low efficiency of the concentration effect of the useful incident radiationAdditionally, in prior art Fresnel type reflecting lenses, the inclined surfaces facing the source of radiation provides a series of surfaces which are exposed to theOMPI ambient environment and has been found to be contaminated with various particulates. Where the inclined surfaces are mirror coated, extreme care must be taken when clean¬ sing such surfaces. This cleansing of the surfaces is a difficult and time consuming operation which increases the overall operation cost of such lens configurations.-WR AtTOMPI BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is an isometric view of a multi-lenticulated lens showing the incident radiation impinging on a planar surface prior to transmission through the lens and re¬ flection from a rear inclined surface;FIG. 2 is a section view of one lenticulation of the lens provided in FIG. 1, taken along the section line 2-2;FIG. 3 is an embodiment of the lens shown in FIG. 1, taken in perspective view providing a refractive Fresnel type lens mounted on a planar mirrored surface;FIG. 4 is a perspective view of a lens having circular lenticulations and a planar surface upon which incident radiation impinges and is refracted to a rear inclined mirrored surface;FIG. 5 is a perspective of an embodiment of the inven¬ tion showing a frontal linearly lenticulated surface having a mirror coating rear surface of planar contour; FIG. 6 is a sectional view of FIG. 5 taken along the section line 6-6;FIG. 7 is an embodiment of the invention showing a lenticulated surface frontally directed toward a source of radiation and having a mirrored back with arcuately formed lenticulations;FIG. 8 is a lens system taken in perspective showing a pair of lenticulated lenses utilizing both refraction and reflection modes of radiation transmission; and,FIG. 9 is an embodiment of. the invention taken in perspective showing a pair of lenticulated lenses having orthogonally extended lenticulations when taken each with respect to the other.IjU EAtTO PI DESCRIPTION OF THE PREFERRED EMBODIMENTSReferring now to FIGS. 1 and 2, there is shown multi- lenticulated lens 10 for reflecting incident electro¬ magnetic radiation 12 from a source S to a linearly di¬ rected focus F through reflected radiation 14. In overall concept, multi-lenticulated lens 10 is directed to a system for the concentration of electro-magnetic radia¬ tion to a focus line F or a focal point through use of optical refraction in combination with optical reflection.- Thus, lens 10 is utilized for concentration of reflected radiation 14 to some line or point spatially located frontally of lens 10 as defined by frontal directional arrow 16. However, it is an important concept of the subject inventive system that incident electro-magnetic radiation 12 is not merely reflected from multi-lenticulate lens 10 to linear focus F but rather is provided with an initial refraction, reflection from a predetermined sur¬ face of lens 10 before emerging from an internal segment of lens 10 to result in reflected radiation 14. Lens 10 as is herein described is of the Fresnel type. In this meaning, as is provided in the instant inventive concept, Fresnel type lenses shall include a lens system which has a plurality of lenticulations formed within at least one surface portion thereof. The lenticulations of the Fresnel type lens, as will be seen in following paragraphs, may be linearly .directed or may be arcuate for some embodiments as is herein described.One of the important uses of the lens system as is herein provided is in solar heat concentration areas of concern. In this vein, the source S may be the sun and focal line F may be in general any heat concentrating focus line where a multiplicity of incident radiation rays 12 may be focused. ■ Thus, lens 10 may be utilized in a solar tracking system utilizing conventional kine¬ matic mechanisms to focus reflected rays 14 into a particular focus line F. Lens 10 may be fixed, such as on the wall of a building, to redirect focused rays im¬ pinging on the lens 10 from a heliostat system. BU EAfT O PI Lens 10 as shown in FIGS. 1 and 2 includes frontal surface 18 which is at least partially transmissive to incident radiation 12. Frontal surface 18 may be planar in contour throughout the plane of surface 18. Addi¬ tionally, when Fresnel type lens 10 is utilized for solar energy reflection, frontal surface 18 is generally maintained in a plane normal to incident radiation 12. Additionally, it is to be understood, that a lens system may be formed of a plurality of frontal surfaces 18, at least one of which being inclined at a predetermined angle. to solar flux radiation rays 12.Lens 10 includes rear surface 20 formed of a plurality of linearly directed lenticulations 22. As can be seen from FIG. 1, lenticulations 22 extend linearly in trans¬ verse direction 24. Rear surface 20 as defined by lenti¬ culations 22 include inclined surfaces 26 when taken with respect to a planr defined by frontal surface 18 and a plurality of surface areas 28 defining the boundary be¬ tween one lenticulation 22 and a successive lenticulation 22. For purposes of illustration, surfaces 28 of FIGS.IJU EOMP wip 1-9 are depicted as being vertically directed. However, it is to be understood that the concept as herein pre¬ sented is meant to encompass surfaces 28 being possibly inclined with respect to frontal plane 18 as well. Each of inclined surfaces 26 is adapted to reflect radiation. Inclined surfaces 26 may be mirror coated with a'high reflective aluminum or some like mechanism to provide a substantially mirror-like reflection coating. Addi¬ tionally, inclined surfaces 26 are seen in FIGS. 1 and 2 to be linearly inclined with respect to a plane defined by frontal surface 18. However, it will be understood, that inclined surfaces 26 may be arcuately inclined in the form of a parabola or some like arcuate contour. In a similar manner, surfaces 28 may additionally be adapted to reflect radiation with a mirror-like coating. The reflection properties associated with surfaces 28 are particularly advantageous when surfaces 28 are in¬ clined as has hereinbefore been described.The provision of providing a planar frontal surfaceijυREATrO PI 18 and a lenticulated rear surface 20 which is mirror coated in a Fresnel lens 10 is particularly advantageous when lens 10 is utilized in a sun tracking system. It is understood that lens 10 may be exposed to the surround¬ ing ambient atmosphere. Thus, frontal surface 18 may become contaminated with dust particulates or other contamination type particles evolving in the surrounding atmosphere. It is thus particularly advantageous to provide a planar type frontal surface 18 exposed to such contaminants in order that surface 18 may be easily cleansed or otherwise have such particulates removed from an optical surface. Additionally, the reflecting surfaces 26 are essentially facing the internal portion of lens 10 and are not subjected to particulate contami¬ nation. If inclined surfaces 26 were exposed to the ambient atmosphere, it is clearly seen that the cleaning process due to the lenticulations 22 would be increasing¬ ly difficult. Still further, it is clearly seen that inclined surfaces 26 would present a cleansing problemOMP *• WIP due to the fact that as an overall surface, rear sur¬ face 20 is non-planar.Of further consideration and most importantly, the back mirror coatings applied to inclined surfaces 26 defines a unique change in the optical properties of incident and reflected radiation rays 12 and 14 respec¬ tively. It has been found, that where frontal surface 18 is the lenticulated surface and particularly where this lenticulated surface is the reflecting surface, that reflected radiation 14 is diminished in flux den¬ sity when focus line F measurements are made. This is caused by the fact that a large portion of reflected radiation rays 14 are lost in that their linear path is obstructed by a next vertical surface 18 of a next consecutive lenticulation 22. This has the effect of reducing the amount of incident radiation 12 emanating from source S which is focused on linear line F.FIG. 2 is a schematic optical ray diagram showing the path of incident radiation ray 12 impinging on frontal surface 18 resulting in transmission ray 30 passing through the width of lens 10 for impingement and reflection from inclined surface 26 which is mirror coated. Transmission ray 30 is transformed after re¬ flection into transmission/reflection ray 32 and results in reflected radiation 14 after passage through the width of lens 10. As is evident, when surface 18 is normal to ray 12, transmission ray 30 is not refracted upon passage therethrough. As is seen in FIG. 2, the letter characters CDE defines the cross-section triangular configuration of one lenticulation. Inclined surface 26 is mirror coated in conformity with the instant concept and the portion of planar frontal member 18 defined by the extension CE is optically transmissive. Incident radiation 12 impinges substantially normal to frontal planar member 18 and passes through with no refraction due to the substantially normal impingement.Reflection of ray 30 from surface 26 occurs at re¬ flection point A. Due to the geometry of the system•WREO PI . AT- W1P0 and the well-known reflection laws, it is seen that: θ, + α = 90° θ.(1)Construction line 27 is formed perpendicular to in^ clined surface 26 and intersects same at point A. Thus, from equation (1) it is evident that: BAI α(2)Formation of construction line IJ parallel to line HA intersects frontal member 18 at radiation egress point I. From plane geometry:' ^ AlJ = < iHAI(3) and: L HAI = ^ HAB + <X BAI + α = 2α(4) gυREA/-OMPI From Snell's Law: N = SIN SIN zSIN (AIJ) SIN (2α)(N) SIN 2α = SIN = XX^ + fα = 1_ 2N {SIN*1 { X } } (5) This defines the lenticulation of the subject concept. In opposition, where the lenticulation sides are mirrored and pure reflection occurs the lenticulation is seen to be: α {SIN-1 {P 2 χ2 + f2 }}Thus, by inspection of equations 5 and 6, it is seen that lenticulations are less than to provide a moreP focused radiation image for the subject concept.OM Referring now to FIG. 3, there is shown another embodiment of the basic lens 10 as provided in FIGS. 1 and 2. In this embodiment, lens system 34 is composed of refractive Fresnel type lens 36 in combination with planar member 38. Planar member 38 includes a mirror coated frontal surface 40 or. mirror coated rear surface 40 for reflection purposes. Planar member 40 inter¬ faces with refractive Fresnel type lens 36 at least some of the apices 42 of lenticulations 22 extending in direction 24. In this lens system 34, inclined, sur¬ faces 26' are substantially transmissive to radiation 12. Thus, incident radiation 12 from source S generally passes through up frontal planar surface 18, is trans¬ mitted to lower inclined surface 26', then passes through a refraction until it is reflected from mirror surface 40 or 41 of planar member 38 wherein it is reversibly passed through refractive Fresnel lens 36 to be emitted as reflected ray 14. * -This embodiment as shown in FIG. 3 includes an addi¬ tional refractive passage of the radiation in that the radiation is emitted from inclined surfaces 26' through a medium such as air to reflective surface 40 and -then is displaced reversibly into lens 36. However, it has been found that there is slight diminution of the focused radiation flux on linear focus line F in this embodiment. Referring now to FIG. 4 there is shown an embodiment of the invention where the concept of refraction and re¬ flecting rays utilized in combination are provided to redirect an incident electro-magnetic radiation ray 12 from a source S to a reflected radiation ray 14 on a point focus F'. In this embodiment, circularly lenti¬ culated lens 44 is utilized for refraction and reflection of incident radiation 12. Circularly lenticulated lens 44 includes frontal surface 46 and rear lenticulated sur¬ face 48. Frontal surface 46 is generally planar in contour and lies in a plane substantially normal to radiation rays 12 from source S when circularly lenticulated lens 44 is utilized in solar reflection uses. Rear surface 48 in¬ cludes arcuately directed lenticulations 50 which are- lJ O defined by inclined reflective surfaces 52 and wall members 54. As was the case of surfaces 28 shown in FIG. 1 wall members 54 may be inclined with respect to a horizontal plane. Inclined surfaces 52 may be adapted to reflect electro-magnetic radiation through a mirror coating such as a highly polished aluminum or some like material and/or technique well-known in the art. ' The advantages found in the utilization of circularly lenti¬ culated lens 44 is similar to those advantages as has hereinbefore been provided when a description of multi- lenticulated lens 10 having linearly directed lenticula- tions 22 were discussed. In this lens system 44, incident radiation 12 is initially passed through substantially transmissive surface 46 and is transmitted to mirror coated surfaces 52 of rear surface 48. The refracted ray is then reflected from inclined surfaces 52 and exits frontal surface 46 as reflected electro-magnetic wave 14. As was the case in lens 10 of FIGS. 1 and 2 , circularly lenticulated lens 44 may be provided with a planar memberIJU E TT0MP1 _Arr WIPO Λ>> interfacing with apices 56. The planar member although not shown may be mirror coated in much the same manner as planar member 38 shown in FIG. 3. In this case, there would be an additional refractive phase of electro¬ magnetic radiation with some loss of focusing at focus point F'. However, this loss of the focusing point F1 may be advantageous in that inclined surfaces 52 which may be linear or parabolic in nature would not have to be mirror coated and thus there would be a lower manufac¬ turing cost.Referring now to FIGS. 5 and 6, there is shown a still further embodiment of the inventive concept where radiation concentration is affected through use of both a refractive and reflective transport mode to produce a linear focusing F. In FIGS. 5 and 6, Fresnel type lens 58 includes lenti¬ culated frontal surface 60 and opposing rear surface 62. Frontal surface 60 includes a plurality of linearly directed lenticulations 64 in transverse direction 24. Further, frontal surface 60 includes inclined radiation transmissiveOMPIArrL W1P0 surfaces 65 to permit passage of incident radiation 12 therethrough. Surfaces or walls 66 may be vertically directed or formed at some angle to planar rear surface . 62.Rear surface 62 is adapted to reflect refracted rays 68 through a mirror backed coating such as polished alumi¬ num or some like material. In this embodiment, it is seen that incident electro-magnetic radiation 12 after passage through inclined surface 65 becomes refracted ray 68 which is then reflected from rear surface 62 to produce refracted/reflected ray 70 before emergence from inclined surface 65 to form reflected ray 14.As was the case in the preferred concepts shown in FIGS. 1-4, Fresnel type lens 58 may be formed in one piece formation of an optically refractive type of material such as glass, plastic, or some like material.FIG. 7 shows a circularly lenticulated Fresnel type lens 72 which is analogous to Fresnel type lens 58 in the same manner as lens 44 shown in FIG. 4 is in relation to lens 10 provided in FIGS.' 1 and 2. Circularly lenticu¬ lated lens 72 of FIG. 7 includes planar mirror coated back or rear surface 74 having lenticulations 76 of an arcuate nature or contour to provide focusing to a point focus in opposition to the line focus F shown in FIGS. 5 and 6. The reflection/refraction optical parameters for circularly lenticulated lens 72 are similar to those provided for linearly directed lens 58. .Although in FIGS. 5-7, frontal surfaces 60 and 78 are lenticulated and exposed to the ambient environment, it is noted that the mirrored surfaces 62 and 74 are not exposed and thus such may be maintained in a relatively easily cleansed fashion compared to the frontal surfaces themselves being mirror coated. Once again, in the embodiments shown in FIGS. 5-7, there is a lower amount of radiation which is impinged or blocked by successive or consecutively spaced lenticulation surfaces when taken with respect to the lenticulated surfaces themselves being mirror coated. This has the effect of increasing the radiation concentra- tion at either a point or' a line focus.Referring now to FIGS. 1-3, it is to be understood that planar surface 18 may additionally be linearly lenticulated in a direction coincident with the lenticu¬ lations 22. Further, in FIGS. 5 and 6, surface 62 may be lenticulated in a direction coincident with lenticu¬ lations 65. Similarly, in FIG. 4, surface 46 may be formed of arcuately directed lenticulations and mirrored surface 74 of FIG. 7 may include similarly directed arcuate lenticulations.Referring now to FIG. 8,.there is shown combined lens system 80 including frontal lens 82 and rear lens 84. As will be seen in following paragraphs, combined lens system 80 is provided for ultimate reflection of incident electro-magnetic radiation 12 from source S to a focus point F' by reflected radiation ray 14. Frontal lens 82 includes a plurality of linearly directed lenticulations 88 formed in transverse direction 24. Rear lens 84 is mounted to rear surface 90 of frontal lens 82 in contiguous-BURE UO PI mating contact through adhesive bonding or some like technique. It is to be understood that particular refrac¬ tive materials may be inserted between frontal lens 82 and rear lens 84 within interstices 85 shown in FIG. 8. Frontal lens 82 is optically or radiation transmissive to provide a refraction of incident ray 12 in passage through frontal lens 82.Rear lens 84 includes a plurality of linear lenticula¬ tions 92 passing in longitudinal direction 86. Although lenticulations 92 of rear lens 84 are generally linearly . directed substantially normal or perpendicular to the extension direction of lenticulations 88 of frontal lens 82, it is within the scope of the concept as herein des¬ cribed to permit lenticulations 92 and 88 to be formed at any predetermined angle between coincidence of the lenticulations and perpendicularity of the lenticulations. It has been found that through the use of a pair of mu¬ tually angled lenticulation directions of frontal lens 82 and rear lens 84, that incident electro-magneticIJUROM _As IP radiation 12 may be focused to a point focus F1. Rear lens 84 includes rear surface 94 which is generally planar in contour and is mirror coated through highly polished aluminum deposition or some like material. Lens system 80 thus provides a system whereby the reflec¬ tive properties of a lens may be utilized in combination with refractive concepts as has hereinbfore been described to produce a concentration of reflected rays 14 to a point focus F1. Combined lens system 80 is of significance since linearly directed lenticulations such as those pro¬ vided by 88 and 92 are of a low cost consideration manu¬ facturing item. Such linear lenticulations may be formed by embossing or in large plane contours may be formed by mill cutting, pressing, rolling, or other means which is inexpensive when compared to circular engraving or other arcuate contours which are now provided for forma¬ tion of Fresnel type lenses in directing incident radia¬ tion to a point focus.As is evident, rear lens 84 may be frontally directed- II EACΓO PI toward source S and be provided as a completely refrac¬ tive type lens. In this type of case, frontal lens 82 would then be displaced rearward from source S and in¬ clined surfaces 96 would be mirror coated for reflection of refracted radiation rays. It has been found' that this arrangement of lenses 82 and 84 also provides for focus to a focus point F*. The important consideration being that combined lens system 80 utilizes two lens 82 and 84 having linearly directed lenticulations 88 and 92 which are inclined each with respect to the other. The mutually inclined lenticulations 88 and 92 when pro¬ vided with one lens 82 or 84 being refractive in nature and a second lens 82 or 84 having a surface reflection area, provides for the advantages of maximizing the in¬ cident radiation 12 into a concentrated reflected ray 14 at a focus point F1.FIG. 9 is directed to an embodiment of combined lens system 80 shown in FIG. 8 where lenticulations 98 and 100 of matingly interfacing lenses 102 and 104 are ortho- gonally displaced each with respect to the other. In the embodiment shown in FIG. 9, lenses 102 and 104 matingly engage along an interface line defining planar contours. Additionally, in the arrangement shown, rear lens 104 includes a series of inclined surfaces 106 which are mirror coated to provide the necessary reflec¬ tive properties. Thus, incident radiation 12 is refrac- tively passed through lens 102 and 104 to impinge and be reflected from lenticulated surfaces 106 of lens 104. The important consideration being that lenticulations 98 of lens 102 and lenticulations 100 of lens 104 are formed inclined each to the other to provide concentration to focus point F , when taken in combination with the re¬ fractive/reflective concept of radiation passage as has hereinbefore been described.In overall concept, one linearly lenticulated lens may be placed.in combination with a second element to focus frontally to at least one point. The lens and element may be positioned contiguous each to the other or lenticu-IJVJR CTO PI' y lations may be formed on opposing surfaces of the entire lens system or alternatively one set of lenticulations may be positioned interior the lens system adjacent the other element.For purposes of optical advantages, as well as mecha¬ nical feasibility, it may be advantageous to present a substantially planar surface to external source S. Thus, where the lenticulations of lens 10 are exposed to the external environment, the interstices between successive lenticulations may be filled with particular refractive materials. Additionally, where the interstices are opposed to a surface facing the source S, such may be filled with refractive or other material to provide ad¬ vantageous mechanical properties for lens 10.In other embodiments, lenticulated surfaces of the herein described lenses may be contoured in a linear hyperbolic, parabolic, circular, toroidal or other arcuate contour.Although this invention has been described in connection.. W1PO with specific forms and embodiments thereof, it will be appreciated that various modifications other than those discussed above may be resorted to without departing from the spirit or scope of the invention. For example, equivalent elements may be substituted for those speci¬ fically shown and described. Certain structures may be used independently of others, and in certain cases, parti¬ cular locations of elements may be reversed or interposed, all without departing from the spirit or the scope of the invention as defined in the appended claims. | WHAT IS CLAIMED IS:1. A radiation concentrating lens for concentra¬ ting incident radiation to a focus, comprising:(a) a frontal surface being at least partially radiation transmissive for passage of said incident ra¬ diation therethrough; and,(b) at least one inclined rear surface of said lens, said rear surface being adapted to reflect radia¬ tion impinging thereon.2. The radiation concentrating lens as recited in claim 1 where said rear surface of said lens is lenti¬ culated to provide multiplicity of lenticulations forming a plurality of reflective rear surfaces. W OMEPI. Λ W1PO 3. The radiation concentrating lens as recited in claim 2 where said inclined rear surfaces are linearly inclined.4. The radiation concentrating lens as recited in claim 2 where said inclined rear surfaces are' arcuately contoured.5. The radiation concentrating lens as recited in claim 4 where said arcuate contour of said inclined rear surfaces is parabolic.6. The radiation concentrating lens as recited in claim 2 where said lenticulations of said rear surface of said lens is linearly directed. 7. The radiation concentrating lens as recited in claim 2 where said lenticulations of said rear sur¬ face of said lens are arcuately directed.8. The radiation concentrating lens as recited in claim 7 where said arcuately contoured. lenticulations include a plurality of circular lenticulations.9. The radiation concentrating lens as recited in claim 2 where said frontal lens is lenticulated in a direction coincident with a direction of said lenticula¬ tions of said rear surface. BUR 0M.A -., I 10. The radiation concentrating lens as reςited in claim 2 where said frontal surface is planar in contour.11. The radiation concentrating lens as recited in claim 2 where said inclined rear surfaces are reflectively coated.12. The radiation concentrating lens as recited in claim 2 where said lens is formed in one piece construction.-fϋRE crOMPl ' 13. A radiation concentrating lens for concentra¬ ting incident radiation to a focus, comprising:(a) a frontal surface being at least partially radiation transmissive for passage of said incident ra¬ diation therethrough;(b) a rear surface being lenticulated to provide a multiplicity of lenticulations forming a plurality of inclined rear surface sections; and,(c) a reflective member adjacent said lens rear surface for reflecting radiation.14. The radiation concentrating lens as recited in claim 13 where said frontal surface is lenticulated in a direction coincident with a direction of said lenti¬ culations of said rear surface.OM P 15. The radiation concentrating lens as recited in claim 13 where said rear surface inclined sections are linearly inclined.16. The radiation concentrating lens as recited in claim 13 where said rear surface inclined sections0 are arcuately contoured.17. The radiation concentrating lens as recited in claim 16 where said arcuate contour of said rear surface sections is parabolic.18. The radiation concentrating lens as recited in claim 13 where said lenticulations of said rear sur¬ face are linearly directed. 19. The radiation concentrating lens as recited in claim 13 where said lenticulations of said rear surface of said lens are arcuately directed.20. The radiation concentrating lens as recited in claim 19 where said arcuately contoured lenticulations include a plurality of circular lenticulations.21. The radiation concentrating lens as recited in claim 13 where said frontal surface is planar in contour.22. The radiation concentrating lens as recited in claim 13 where said reflective member is reflectively coated for reflecting radiation impinging thereon.O P_A _ IP 23. The radiation concentrating lens as recited in claim 22 where said reflective member is planar in contour and contiguous a set of apices of said lenti¬ culations.24. The radiation concentrating lens as recited in claim 23 where said reflective member is secured in constrained contact to said lenticulation apices.25. A radiation concentrating lens for concentra¬ ting incident radiation to a focus, comprising:(a) at least one frontally inclined surface being at least partially radiation transmissive for • passage of said incident radiation therethrough; and,(b) a rear surface of said lens being adapted to reflect radiation impinging thereon.ijύ E tTOMPI A ri WΪPO , ^> 26. The radiation concentrating lens as recited in claim 25 where said frontally inclined surface is substantially hyperbolic in contour.27. The radiation concentrating lens as recited in claim 25 where said frontal surface of said lens is lenticulated to provide a multiplicity of frontal sur¬ face lenticulations.28. The radiation concentrating lens as recited in claim 27 where said rear surface is lenticulated in a direction coincident with said lenticulations of said frontal surface.-BU EOMP 29. The radiation concentrating lens as recited in claim 27 where said inclined frontal surfaces are linearly inclined.30. The radiation concentrating lens as recited in claim 27 where said inclined frontal surfaces are ar¬ cuately contoured.31. The radiation concentrating lens as recited in claim 30 where said arcuate contour of said inclined frontal surfaces is parabolic.32. The radiation concentrating lens as recited in claim 27 where said lenticulations of said frontal sur¬ faces is linearly directed.IJURE £TOMPI 33. The radiation concentrating lens as recited in claim 27 where said lenticulations of said frontal surface of said lens are arcuately directed.34. The radiation concentrating lens as recited in claim 33 where said arcuately contoured lenticulations include a plurality of circular lenticulations.35. The radiation concentrating lens as recited in claim 27 where said rear surface is planar in contour.36. The radiation concentrating lens as recited in claim 35 where said rear surface is reflectively coated.O <fy. WIP 37. The radiation concentrating lens as recited in claim 25 where said lens is formed in one piece con¬ struction.38. The radiation concentrating lens as recited in claim 25 where said lens is formed of a substantially optically transparent material.39. A radiation concentrating lens system for con¬ centrating incident radiation to a focus, comprising:(a) a first frontal linearly lenticulated lens element having lenticulations extending in a first direction, said first lens being at least partially transmissive to said radiation; and,(b) a second rear element, said second rear element having a surface adapted to reflect radiation impinging thereon. 40. The radiation concentrating lens system as recited in claim 39 where said second rear element is a linearly lenticulated lens having lenticulations ex¬ tending in a second direction, said first and. second lens elements being mounted each to the other in a contiguous manner.41. The radiation concentrating lens system as recited in claim 40 where said first frontal lens in¬ cludes :(a) a first lenticulated surface having lenti¬ culations extending in said first direction; and,(b) a second rear surface being planar in contour, said first lens being at least partially trans¬ missive to said incident radiation. 42. The radiation concentrating lens as recited in claim 41 where said second rear lens includes:(a) a first lenticulated surface having len¬ ticulations extending in said second direction, said first lenticulated surface being contiguous said second rear surface of said first frontal lens; and,(b) a second rear surface of sa.id second rear lens being adapted to reflect radiation impinging thereon.43. The radiation concentrating lens as recited in claim 42 where said second rear surface of said second rear lens is planar in contour.' 44. The radiation concentrating lens as recited in claim 42 where said first lenticulation direction is non-coincident with said second lenticulation direction. 45. The radiation concentrating lens system as recited in claim 44 where said first lenticulation direction is substantially normal said second lenti¬ culation direction.46. The radiation concentrating lens system as recited in claim 40 where said second rear lens in¬ cludes:(a) a first planar contour surface being contiguous said second rear surface of said first frontal lens; and,(b) a second lenticulated surface having lenticulations extending in said second direction, said second lenticulated surface being adapted to reflect radiation impinging thereon. 47. The radiation concentrating lens system as recited in claim 46 where said second surface of said second lens is reflectively coated.48. The radiation concentrating lens system- as recited in claim 46 where said first lenticulation direction is non-coincident with said second lenticu¬ lation direction.49. The radiation concentrating lens, system as recited in claim 48 where said first lenticulation direction is substantially normal said second lenticu¬ lation direction. 50. The radiation concentrating lens system as recited in claim 40 where said frontal lens includes:(a) a first planar surface being at least partially transmissive to said incident radiation; and,(b) a second rear surface being lenticulated in said first direction, said second rear surface being at least partially transmissive to said radiation.51. The radiation concentrating lens system as recited in claim 50 where second lens includes opposing first and second surfaces, said second surface being lenticulated in said second direction.52. The radiation concentrating lens system as recited in claim 51 where said second lenticulated sur¬ face of said second lens is contiguous said second rear surface of said first frontal lens. 53. The radiation concentrating lens as recited in claim 52 where said first surface of said second lens is reflectively coated.54. The radiation concentrating lens as recited in claim 51 where said first surface of said second lens is contiguous said second rear surface of said first frontal lens, said first surface of said second lens being substantially planar in contour.55. The radiation concentrating lens as recited in claim 54 where said first and second directions of said lenticulation extensions are non-coincident.56. The radiation concentrating lens as recited in claim 55 where said first and second directions are substantially normal each to the other.OMPI | BUNCH J | BUNCH J |
WO-1979000186-A1 | 1,979,000,186 | WO | A1 | XX | 19,790,419 | 1,979 | 20,090,507 | new | B29D27 | null | B29C39, B29C44, B29K105 | B29C 44/46C | FLAT TOP FOAM MATERIAL METHOD AND APPARATUS WITH WIDTH CONTROL | An apparatus for producing a foamed sheet of material has a mixing head (14) mounted on a frame (45) which is positioned on a track (62) for longitudinal movement. The mounting for the mixing head also engages a worm gear (50, 50a) for vertical movement. Below the mixing head is a sloped portion (22) of a conveyor. The sloped portion of the conveyor comprises a pair of stationary central panels (202) and a right and left pair of panels (198, 200). Each pair of panels is hinged together and slide toward and away from the longitudinal axis of the central panels. A paper sheet (24) slides over the panels onto a level bottom conveyor. Vertical side fences (32) are adjacent the side edges of the bottom conveyor panels. A paper sheet (34) slides along the inside surface of each side fence at the same speed of the bottom sheet of paper. A worm gear (158) adjusts the distance between the side fences. The sloped portion of the conveyor has a height adjustment mechanism (132, 158, 160) at its upper and lower end and at the hinged portion of the panel. The central panels have air passages (208) therethrough. A blower is operably connected to the air passage to blow air therethrough and under the paper sheet to glide the paper along the sloped conveyor. | ADJUSTABLE APPARATUS FOR PRODUCING A FOAM MATERIALTechnical FieldThis invention relates to continuous production of foam material and more particularly to an apparatus which produces substantially flat top foam materials of differ- 5 ent widths- Background ArtFoam sheets have been made from a liquid polyure- thane foaming material spread on a continuously moving channel-shaped conveyor. The problem encountered with 0 this type of apparatus is that the side fences of the conveyor cause a downward drag on the rising foam, re¬ sulting in a convexly curved top on the sheet. For most uses of the foam, such as for furniture, the tops have to be flat to produce a desired seating surface. Most often15 the convexly shaped tops were cut to a flat top and the removed material was scraped.Side fences have been developed which not only move with the bottom conveyor but also move upwardly with re¬ spect to the bottom conveyor where the foam rises to lessen20.. or eliminate any downward drag caused by the side fence. Such side fence mechanisms are disclosed in U.S. patent 3,325,82β issued to Boon on June 13, 1967, and U.S. patent 3,091,811 issued to Hackert on June 4, 1963.These devices are limited to a variety of foaming25 materials which can be used, since different foaming materials have different foaming rates. If the foaming rate is too fast, the drag is not eliminated and if the foaming rate is not fast enough, the side fences could cause upward drag, resulting in a concave top surface,30 a feature as undesirable as the convex top.The sloped portion of the conveyor has to have its slope adjustable. U.S. Patent 3,832,099 issued to Berg on August 27, 1974 discloses a vertically adjustable section of the bottom conveyor.35 The apparatus using a sloped bottom conveyor and upwardly inclined side conveyor adequately produce flat top foam blocks which can be cut to whatever desired length after the foaming is completed. However, if narrower foam blocks are desired, the foam blocks have to be sheared to form the narrower foam block. The cut- ting creates a waste of foam plus an extra process in making the final foam block. Disclosure of InventionAccording to the invention, an apparatus for con¬ tinuously casting foam sheets has a bottom conveyor posi- • tioned below a means for supplying liquid foaming reagents thereto. Sidewalls are adjacent the conveyor to retain the foam as it rises on the conveyor. The side walls preferably have a surface moving in the direction of. the foam and at the same relative speed. Preferably the surface is a paper sheet supported by a longitudinally stationary supportive wall. Means for controlling the upper contour of the rising foam are alongside of the side fences at a first portion of the conveyor. Prefer¬ ably a means for controlling the upper contour of the foam includes the first portion of the conveyor angled down¬ wardly with respect to the sidewalls.Means are connected to the side walls for adjustably moving the sidewalls for controlling the width of the space between the sidewalls such that the width of the foamable material on the conveyor is adjustable. Also means adjust the width of a portion of the conveying means. Preferably the adjusting means include the first portion of the con¬ veyor longitudinally divided into at least two platforms with sliding means connected to each platform for sliding one longitudinal platform with respect to another in a horizontal direction transverse to the length of the con¬ veyor. It is desirable that the side walls are adjacent the outer edges of the first portion of the conveyor. Means for covering the gaps between the platform is connected to at least one platform.Further, according to the invention, the conveying surface of the conveyor is a flexible sheet which conveys the foaming material as the material is molded. Means for fitting the flexible sheet between the spaced side walls are attached to the conveyor upstream from the side walls such that the outer edges of the sheet are adjacent the side walls.Brief Description of DrawingsThe invention will now be described with reference to the accompanying drawings in which:Figure 1 is a side elevational view of a conveyor system illustrating a preferred embodiment of the inven¬ tion.Figure 2 is a partially segmented enlarged side' elevational view of the embodiment illustrated in Figure 1. Figure 3 is a partially segmented enlarged side view of the embodiment shown in Figure 2 in a second position of the conveyor.Figure 4 is an enlarged fragmentary and partially broken plan view of the embodiment shown in Figure 1. Figure 5 is a side cross-sectional view taken along lines 5-5 in Figure 4.Figure 6 is a side cross-sectional view as shown in Figure 5, showing a second position of the side walls.Figure 7 is a skeletal perspective view of the adjustable stands of the preferred embodiment of the invention.Figure 8 is an enlarged elevational view of a paper cutter as shown in Figure 2 taken along lines 8-8 in Fig¬ ure 2. Best Mode for Carrying out InventionReferring particularly to Figure 1, an apparatus generally indicated as 10 has a frame 12 supporting a mixing head 14. Various hoses 16, tanks, and pumps are connected to the mixing head in a conventional fashion for supply of foamable liquid. A conveyor 22, originating from a paper roll 24 passes over and is supported by a -F.τ.«. -oortion 26 called a pour plate, passing under mixing head 14, and passes over and is supported by a second portion 28 and third portion 29 extending from the pour plate 26 to a foam saw apparatus 30. The pour plate 26 is disposed at an acute angle to the horizontal. At the 5 sides of the conveyor 22 are side fences 32. A paper roll 34 has its paper 35 unwind and abut the inner surface of the side fences 32 to a take up roll 36.As more clearly shown in Figures 2 and 7, the mix¬ ing head 14 is attached to chain 38 which is trained1.0 around sprockets 40 and driven by motor 42. The mixing head 14 is driven back and forth, traversing the width of the conveyor. The sprockets 40 are contained in a sprocket housing 44.A worm gear 45 is operably mounted within the frame15 12. The worm gear 45 is operated by handle 46 through gear reducer 48. The reducer 48 turns the worm gear shaft 50. The gear reducer is mounted on frame 12. The bottom of the worm gear shaft 50 is also rotatably mounted on the frame 12. A brass block 56 has stabilizer lugs 58 which20' engage the frame 12. The threaded block 56 also engages the gear shaft 50 so when the shaft rotates, the threaded brass block is raised or lowered. The sprocket housing 44 is also connected to the brass block 56 and is correspond¬ ingly raised or lowered. At the bottom of the gear shaft25 50 is a sprocket 54. A chain 63 is trained around the sprocket 54 and engages a sprocket 54a as seen in Figure 7 at the other side of the conveyor which also is attached to a worm gear shaft 50a of a worm gear 45a similar to the one described but lacking the gear reducer and handle.30 The sprocket housing 44a at the other side of the conveyor is similarly connected to a brass block 5.6a which is similarly raised or lowered by the rotation of handle 46. Handle 46 can be also replaced by a motor which drives the gear reducer 48.35 The mixing head frame 12 is mounted oh bases 52 which slidably ride on tracks 62. Each base 52, as shown in Figures 5 and 7, is connected by a transverse bar 64 which, in turn, is connected to a motor housing 70. The motor housing 70 is mounted on a stationary worm gear shaft 68. The motor rotates a threaded brass block 66 which engages the worm gear shaft 68. As the brass block threads up and down the shaft 68, the bases 52 slide within their tracks 62.Referring back to Figure 2, the pour plate 26 is positioned below the mixing head 14. The pour plate 26 is divided into an upper section 74 and lower section 76, hinged together by hinge 78. At the lower edge 80 of the lower section 76, a transition plate 82 is connected to the lower section 76 by hinge 84.Referring now to Figures 2 and 4, the pour plate 26 is supported by three pairs of stands: 86a and 86b, 90a and 90b, and 88a and 88b. One stand 86a, 88a and 90a of each pair, is positioned at the near edge of conveyor. The other stand 86b, 88b and 90b of each pair is positioned at the far edge of the conveyor. Stands 86a and 86b support the upper edge 92 of the upper section 74. The pair of ' stands 88a and 88b support the lower edge of the upper section 74 near hinge 78. The third pair of stands 90a and 90b supports the lower edge 80 of the lower section 7-6 near hinge 84.Each of the stands 90a, 92a and 94a contains worm gears 96a, 98a, and 100a, respectively. The worm gears are the same general type as worm gear 45 connected to mixing head 14. The worm gears 96a, 98a and 100a each has a rotatable handle 102a, 104a and 106a, respectively. Each handle is respectively connected to gear reducer 108, 110 and 112 which are connected to a top end of worm gear shaft 114, 116 and 118, respectively. Each gear shaft is rotatably mounted onto a vertical gear housing 126, 128 and 130, respectively. Brass blocks 132, 134 and 136 having threaded holes threadably engage the worm gear shaft 114, 116 and 118, respectively. Brass block 132 is rigidly connected to bracket 156 which is connected to central track 138.As shown in Fiαure 7, rotatably mounted to the brass BυREΛt/-OMPI blocks 134 and 136 are brackets 158 and 160 extending toward the central portion of the conveyor 22. The brackets 158 and 160 have vertical extensions 164 and 166 respectively mounted to slide tracks 140 and 142. Figure 5 shows another view of the bracket 158 and vertical extension 164.At the bottom of worm gear shafts 114, 116 and 118 are sprockets 144, 146 and 148, respectively. Chain 150 is trained around sprockets 144 and 144a; chain 152 is trained around sprockets 146 and 146a; and chain 154 is trained 'around sprockets 148 and 148a. Each sprocket is connected to a like worm gear shaft 114a, 116a and 118, respectively. Each worm gear shaft is rotatably mounted in housing 126a, 128a and 130a, respectively. Brass blocks 132a, 134a and 136a are threaded onto the respective shafts 114a, 116a and 118a. Brass blocks 134a and 136a are rigidly connected to brackets 158a and 160a. Vertical extensions 164a and 166a connect the re¬ spective brackets onto the slide tracks 140 and 142. Brass ' -block 132a is connected to track 138.The rotation of the handles 102, 104 and 106 re¬ spectively rotate the worm gear shafts 114, 116 and 118, and the sprockets 144, 146 and 148. The chains 150, 152 and 154 move to correspondingly rotate the shafts. • As the worm gears are rotated, the threaded brass blocks 132, 132a, 134, 134a, 136 and 136a are raised and lowered on the shafts 114, 114a, 116, 116a, 118 and 118a. The brackets 156, 158 and 160 and 156a, 158a and 160a also are correspondingly raised and lowered which, in turn, raise or lower pour plate 72.As shown in Figure 3, compared to Figure 2, the upper and lower sections 74 and 76 of the pour plate 26 can be adjusted to different heights and different in¬ clinations. Referring now to Figures 4, 5 and 7, the pour plate 26 is longitudinally divided into three platforms or panels 168, 178.and 188. The vertical extensions 164, 164a, 166 and 166a are attached to center tracks 140 and 142, respectively. Brackets 156 and 156a are directly attached to center track 138. Each center track 138, 140 and 142 is mounted transversely to the length of the conveyor to a bottom surface of a central panel 168 of the pour' plate 72. The central panel 168 has an upper section 169 and lower section 170 corresponding to the upper and lower sections 74 and 76 of the pour plate 72.Slidably mounted to the central tracks 138, 140 and 142 respectively are left tracks 172, 174 and 176. Left tracks 172 and 174 are mounted to a bottom surface of a left panel 178 of the conveyor pour plate. Again, the left panel 178 has an upper section 179 and a lower sec¬ tion 180 corresponding to the upper section 74 and lower section 76 of pour plate 26. Likewise, right tracks 182, 184 and 186 are at¬ tached to the right panel 188 of the pour plate 72. Again, the right panel is also hinged between an upper section 189 and a lower section 190 thereof.Particularly referring to Figures 4 and 5, the central panel 168 is a hollow elongated channel with a bottom strip metal interfitted on a top strip 192.Likewise, the left and right portions 178 and 188 respectively have a bottom strip 194 and 196 interfitted with a top strip 198 and 200. The left and right panels 178 and 188 are slidable toward and away from the central axis of a central panel 168. Attached to the top strip 192 is a cover piece 202 which extends outwardly from the outer edges of the top strip 192 and bridges the gaps 204 between the central panel 168 and left and right panels 178 and 188, respec¬ tively.As shown in Figures 4, 5 and 6 an air hose 206 is connected to the bottom strip 191 of the central panel 168. A plurality of apertures 208 extend through the top strip 192 of panel 168 and also through the cover piece 202 to be in fluid communication with the air hose 206. A blower 211 is op'erably connected to the air hose 206 to blow air through the air hose through the upper and lower sectionOMPI 169 and 170 of..central panel 168.Attached to the bottom of the side panels 178 and 188 are flanges 210. The bottom edge of each flange is welded to a threaded shaft 212. The threaded shaft ex- tends through a slot 214 within brackets 216. Nuts 217 threadably engage the shaft 212 at both sides of brackets 216. The brackets 216 extend upwardly and are affixed to the side fence 32.Referring to Figures 2 and 7, vertical supports 220 and 221 extend upwardly from each side fence 32. The vertical supports are attached to the side fence 32. The base 223 and 225 of the vertical supports are slidably mounted on track 227. At the top of the vertical supports 220 and 221 are housings 222 and 229, each of which rigidly secures brass nuts 224 and 224a, respectively. The brass nuts 224 and 224a engage a threaded shaft 227 with the left side thereof threaded in one direction and the right side threaded in the opposite direction. The shaft 226 is operably connected to a motor 228 such that ' when the shaft 226 rotates, the left brass nut 224a and right brass nut 224 will be simultaneously moved axially along the shaft to slide the supports along stationary track 227 and move the side fences 32 toward the central longitudinal axis of the conveyor, or away from the said axis. As the side fences 32 move to and from the central axis, the left and right panels 178 and 188 correspondingly move under the cover piece 202, either toward or away from the central longitudinal axis of the conveyor.Referring particularly to Figures 5 and 6, the conveyor is shown in two distinct positions with the side fences 32 and side panels 178 and 188 located toward the central axis of the conveyor 22 in Figure 6.As shown in Figures 1 and 2, a paper roll 24 unwinds paper 232 to cover the panels 168, 178 and 188 and contin- ues through the second portion 28 of the conveyor 22. The paper 232 has a width adapted to fit the conveyor at the widest position as shown in Figure 5.Mounted in proximity of the top edge of the firstOM port on 6 o the conveyor are paper ro ers 0 to o the outer edges 234 of the paper sheet 232 from the paper roll 24. The outer edges 234 are folded vertically by rollers 230. Downstream from the paper rollers 230 and fixedly connected to the side fences by supports 236 is a paper cutter 238. The paper cutter is located above each outer edge of the side panels 178 and 188 as shown more clearly in Figure 8. The paper cutter has two vertical plates 240 and 242 placed parallel and slightly to the inside of the side fences 32. A relatively thin space 243 lies between the two opposing plates 240 and 242. The opposing plates have at their top portions supports 244 which extend through the side panels and are fixedly connected thereto. A horizontal slot 245 extends through both plates 240 and 242. A knife blade 246 with its plane parallel to the plate of the upper section 74 of the pour plate 72 has a cutting edge toward the paper roll 24. The knife blade 246 cuts excess height from the vertical outer edges 234 of the paper 232 as the paper 232 travels along the con¬ veyor 22 and retains a vertical lip 235.In operation, a liquid foamable material 11, such as polyurethane, passes out of the mixing head 14 onto the moving paper 232. The moving paper has its outer edges vertically folded by the paper rollers 230. Before the foam 11 rises any significant amount, the vertical edges of paper 232 are cut* by the paper cutter 238. The paper and foamable material move downstream to where the side paper rolls 34 unwind paper 35 to the inner surface of the side fences 32. Both of the side fence papers 35 move at the same speed as the paper 232, As the paper 232 moves downwardly down the slope pour plate 26, the foam 11 rises above the lip 235 and abuts the side fence paper 35, The foam rises at approximately the same rate as the paper 232 declines down the lower section 76 of the inclined pour plate 26. It should be apparent from the foregoing. that most of the foaming takes place on the lower section 76 of the pour plate 26 although a small amount of foaming takes place at the upper section 74 thereof and the final stages of foaming take place on the horizontal conveyor portion 28 as illustrated in Figure 2. The upper section 74 is positioned at a slight angle or declination to the horizontal to permit the foaming ' material, while it is relatively fluid, to reach the point at which substantial foaming begins and it becomes viscous enough to accommodate the steeper declination angle of the lower section 76 without significant flowing down the pour plate. When the foam has substantially reached its final height, the paper 232 passes over the transition plate 82 onto the horizontal second portion 28 of the conveyor 22. The foam is still retained by the side fences until it reaches the end of the second portion 28. The foam is then set to freestanding form as it moves down to the third portion 29 of the conveyor 22 and then to the saw 30 where the foam is cut into blocks of predetermined lengths.As shown in Figure 5, when a narrower foam block is ' desired, the motor 228 rotates the worm gear shaft 226 mounted above the side fences 32 and the brass nuts 224 and 224a are moved inwardly toward the center of the shaft. The side fences are then moved closer together and simul- - taneously the side panels 178 and 188 slide inwardly on the tracks 172, 174, and 176 and 182, 184, and 186 along the center tracks 138, 140, and 142. The mixing head pours liquid foamable material onto the paper 232 as the paper 232 moves downstream along the conveyor 22. The outer edges 234 of the paper 232 is folded upwardly and the cutter 238 cuts the excess height off the outer edges to retain a lip 235 of approximately one inch. The foam 11 foams in the same manner as previously discussed and is retained by the now closer side fences 32. The excess paper 237 cut by the paper cutter, 238 is moved upwardly along paper 35 as the foam rises therealong.Different foams, having different foaming rates, must be accommodated to achieve the flat top which is desired in foam blocks. Adjustments can be made to the foaming head by moving it longitudinally with respect to the conveyor by operation of motor 70 which moves the mix¬ ing head frame 12. The height of the mixing head can also be adjusted by the operation of the handle 46 connected to worm gear 45.In addition, the inclination of the upper section 74 and lower section 76 of the pour plate 72 can be ad¬ justed so that the relative rise of the side paper 35 can be increased or decreased as shown in Figures 2 and 3. The operation of worm gears 96, 98, and 100 adjust the height and inclination of the upper section 74 and lower section 76 of the pour plates 72 with respect to the side fence 32. Adjustments to the inclination of the upper section 74 and lower section 76 of the pour plate 72 may be desired even when the same foam is used if the side fences 32 are differently spaced apart.The vertical lip 235 of the paper 232 is slightly spaced from the side fences so that friction between the two papers 35 and 232 is minimized. The side fences 32 can be adjustably spaced from the side panels and vertical lip 235. As shown in Figures 5 and 6, the nuts 218 can be threaded along the shaft 212 to horizontally move the brackets 216 and consequently the side fences 32 relative to the side panels 78 and 88 to bring the side fence closer to the vertical lip 235 or slightly farther away from the vertical lip 235.As the paper 232 moves downstream, it floats on a thin film of gas supplied through the plurality of aper¬ tures 208 through the cover plate and central panel. The thin film reduces drag on the conveyor until the paper 232 flows into the second portion 28 of the conveyor.In this fashion, a continuous foam molding apparatus can be adjustable to make flat foam blocks of different widths and heights. The side fences are free to move in and out without interference from the sloped pour plate therebetween. The sloped pour plate is correspondingly adjustable to retain its outer edges adjacent the side fences in a plurality of positions while retaining a substantially flat surface width wise suitable for receiv¬ ing foaming reagents thereon.Reasonable variation and modification are possible within the scope of the foregoing disclosure, drawings, and the apended claims without departing from the spirit of the invention. | CLAIMS1. An apparatus for continuously molding a foam¬ able material comprising: - a conveyor support having a flat upper surface por¬ tion at a declination to the horizontal slight enough to substantially preclude liquid foamable reactants from flowing therealong, a flat lower surface portion joined to the upper portion and at a declination to the horizon- tal greater than that of the upper portion; and a longer horizontal curing portion joined to the lower portion; the conveyor support being of a length to permit substantially complete foaming of the foamable reactants thereon; means operatively associated with said conveyor support for conveying the foamable material over the conveyor support from the upper portion to the horizontal curing portion thereof; means mounted above the conveyor support upper por¬ tion for supplying unfoamed liquid foam reactants to the conveying means at the upper surface portion of the con¬ veyor support; means for controlling the upper contour of the molded foam including side wall surfaces moving along adjacent the conveying means and at an inclined angle with respect to the upper and lower portions of the con¬ veying means; and means connected to the supplying means for adjust¬ ing the longitudinal position of the supplying means to adjust the lay-down point of the foamable materials on the conveyor with respect to the upper portion of the conveyor support.2. An apparatus as defined in claim 1 and further comprising: means for adjustably moving at least one side wall surface in a direction transverse to the plane of the side wall surfaces to control the width of the space between the side wall surfaces; and means for adjusting the width of the upper and lower portions of the conveyor support to correspond to adjustments to the side wall position. _ 3. An apparatus as defined in claim 2 wherein: a first portion of the conveyor support is longitu¬ dinally divided into at least two spaced platforms: means are attached to each platform for sliding the platforms with respect to each other in a horizontal direc- tion transverse to the length of the conveyor whereby gaps are formed therebetween; means for maintaining the outer edges of the plat¬ forms adjacent the side walls as the platforms slide with respect to each other; and means positioned between the platforms for covering the gaps between the platforms such that the covering means and platforms form a substantially flat surface in the direction transverse to the length of the conveyor.4, An apparatus as defined in claim 3 wherein: the conveying means includes a flexible conveying surface supported by the platforms and covering means; and means connected to the upper portion of the con¬ veyor support upstream from the side walls for fitting the flexible conveying surface between the side walls.5. An apparatus as defined by claim 4 wherein the fitting means includes a cutting means for cutting excess width from the flexible conveying surface.6. An apparatus as defined in claim 5 and further comprising: means connected to the upper portion of the con- veyor support for folding the outer edges of the flexible conveying surface upwardly to form a retaining lip; and the cutting means is positioned to cut excess height from the retaining lip to minimize drag between the lip and foamable material. . An appara us as e ne n c a m an urt er comprising: means connected to the first portion of the plat¬ forms for controlling the height of the upstream and down- - stream ends of the first portion of the conveyor support.8. An apparatus as defined in claim 7 and further comprising: means connected to a longitudinal midsection of the platforms and cover means for hinging the upper sections of the platform and cover means to the lower sections of the same; and means connected to the platforms adjacent the hinge means for controlling the height of the midsection of the platforms and cover means.9. An apparatus as defined in claim 4 and further comprising: means extending through at least one of the plat- ' forms and cover means for passing a gaseous stream under the flexible conveying surface to form a gaseous cushion between the platforms and cover means, and conveying sur¬ face.10, An apparatus as defined in claim 9 wherein the passing means includes an inlet passage in the bottom sur¬ face of one platform and a plurality of small apertures in the top surface of the platform in fluid, communication with the inlet; a plurality of apertures extending through the cover means in fluid communication with the apertures in the platforms; a blower means is operably connected to the inlet for blowing air through the inlet and apertures to form an air cushion under the flexible conveying surface.11. An apparatus as defined in claim 3 wherein: a left platform and right platform are each slidablyOMPI fe?NATiO connecte by t e s ng means o a centra p a orm; the cover means is a thin top sheet attached to the central platform, extending over the side edges of the cen¬ tral platform, overlapping the inner side edges of the left - and right platforms to cover the gaps between the edges of the central and left and right panels.12. An apparatus according to claim 1 and further comprising means to adjust the vertical position of the liquid supply means with respect to the upper surface por¬ tion of the conveyor support to maintain constant the spac¬ ing of the liquid supply means with respect to the upper surface portion of the conveyor support at different longitudinal adjusted positions of the liquid supply means with respect to the conveyor support upper portion.13. An apparatus as defined in claim 1 wherein: the supplying means includes a mixing head mounted above the conveying means; and means for traversing the ■ upper portion of the conveyor with the mixing head..14. An apparatus as defined in claim 1 wherein the longitudinal position adjusting means for the liquid sup¬ ply means includes a frame mounting the supplying means, the frame movably mounted on a track means adjacent and which is parallel to the conveying means such that the frame is movable in the direction of the conveying means.15. An apparatus as defined in claim 14 and fur- ther comprising motor means operably connected to the frame for moving the frame in the longitudinal direction of the conveying means.16. A method for continuously molding foamable material on a conveyor having longitudinally movable side walls, the method comprising the steps of: laying mixed and unreacted liquid foamable reactants down on a conveyor surface which is oriented at a .I UROM I V ? horizontal declination slight enough to preclude signifi¬ cant flow of the liquid reactants down along the conveyor surface; moving the conveyor surface along the slight hori- - zontal declination while the reactants commence foaming; thereafter moving the surface down a steeper declination whose length and slope generally conform to the degree of rise of the foam as it moves down the steeper declination; moving the side walls at an inclined angle with re¬ spect to the movement of the conveyor .surface down both the slight and steeper declinations so that the side walls move upwardly with respect to the conveyor surface as the foam rises; moving the surface and the side walls parallel to each other subsequent to completion of the foaming; and adjusting, in the longitudinal direction, the lay- down point of the foamable reactants on the conveyor sur¬ face at the slight declination so that the foaming reactants foam sufficiently thereon to maintain their position on the surface as the surface moves the reactants down along the steeper declination and to substantially complete foaming of reactants on the steeper declination. | EDGE IND INC | DILLARD J |
WO-1979000190-A1 | 1,979,000,190 | WO | A1 | EN | 19,790,419 | 1,979 | 20,090,507 | new | A61F7 | A61G7 | A61F20060101SI20051110RMEP, A61F7 | A61F 7/02, A61F 7/02A, K61F 7/00A | HEATING PAD | A heating pad intended for being carried on the body, in particular for patients suffering from rheumatic and other ailments which make it necessary for some parts of the body to be kept warm. The pad consists of an envelope (1) provided with an insert (2) consisting of one or more flexible sheets (3) of Plastics material, each sheet being provided on one face or both with a protruding pattern of plastics material consisting of a great number of air- or gas-filled bubbles or small bodies (4). The insert (2) preferably consists of a plurality of interconnected thin, flexible sheets (3) which on one face are provided with a great number of evenly distributed, preferably circular, hollow air-filled protuberances (4) of soft plastics material. The heating pad, which may have any convenient shape and size, can be provided with a belt (5) of elastic material, whereby it can be fastened in the desired position on the body of the carrier. It can also form part of garments, e.g. be inserted in the shoulder region, the back and/or the front part of a waistcoat or jacket. | Heating padTechnical fieldThe present invention relates to a heating pad inten¬ ded in particular for patients suffering from rheumatic and other ailments which make it necessary for some parts of the body to be kept warm.Background of the inventionElectric heating pads, in particular, have hitherto been used for that purpose. Such pads, however, cannot be used when the patients are out of doors oτ when they are moving around. One has to use, instead, an insulating ma¬ terial of one kind or another, e.g. camel-hair articles, but one cannot thereby keep a sufficiently high temperature of the skin in the sick regions. • Mattresses and sitting pads provided with inserts of foamed plastics for protection from cold are known, cf. for instance the German OS No. 2 033 981 and No. 2 30793S. The inventor has, in connection with the development of the present invention, examined whether this material could be used for heating pads to be carried on the body, but it has proved that said material does not give an adequate thermal effect.Description of the inventionIt has now been found, according to the 'invention, that an adequate thermal effect can be achieved by u^ of a special insulating material which is characterised by a great number of air- or gas-filled bubbles or small bodies. The heating pad according to the invention, which is based upon this recognition, consists of an envelope pro¬ vided with an insert of insulating material, and the cha¬ racteristic feature of the invention is that the insert consists of one o more flexible sheets of plastics mate¬ rial, each sheet being provided on one face or both with a protruding pattern of plastics material consisting of a great number of air- or gas-filled bubbles or small bodies.When the heating pad is being used, warm air will be stored in these small bubbles, and- the heating pad will consequently be in a position to retain the body heat to such an extent that, under the pad, a skin temperature of e.g. up to 36.5 C can be reached.The surface area of the air-filled pattern can advantageously amount to at least 20 of- the surface of the sheets.When use is made of a plurality of sheets, these are preferably welded together at their edges, so as to cons¬ titute an insert consisting of coherent sheets.The envelope is made preferably of soft fabric, e.g. flannel, and is preferably detachable, e.g. provided with a bur -type fastener.Preferred embodiment.A particularly suitable heating pad consists, accor¬ ding to the invention, of a plurality of interconnected thin, flexible plastics sheets which on one face are pro¬ vided with a great number of evenly distributed, preferably, circular, hollow air-filled protuberances- of soft plastics material.Such a. material is manufactured, for instance, by the firm of NPE Emballage A/S, Haslev, Denmark. Description of drawingIn the drawing. - Fig. 1 shows schematically, on a reduced scale, an embodiment of the heating pad according to the invention seen from the face intended for contact with the body of5 the user, a corner of the envelope having been removed so as to make it possible to see the upper insert sheet, andFig. 2 shows schematically, on a reduced scale, the same embodiment in perspective, a corner being shown open 0 so as to allow a view of the insert which is also open. In the drawing, 1 is an envelope, e.g. of flannel. 2 (Fig. 2) is an insert consisting of thin, flexible, transparent plastics sheets 3 which are provided on one face with a great number of protuberances 4 evenly dist- 5 ributed, consisting of air-filled bubbles of thin soft plastics material. The sheets are welded together at their edges. In the embodiment shown, the sheets are disposed so that one surface - the one facing the body of the user - shows protuberances, while the other surface is smooth. 0 The heating pad is provided with a belt 5 of elastic material, whereby the pad can be fastened in the desired position.6 (Fig. 1) represents a bur -type fastener, e.g. the fastener sold under the trade name of Velcro. 5 In the embodiment shown, the surface area of the soft air-filled protuberances constitutes about 25 of the sheet area. Their height, in natural size, is about 2 mm.In order to attain a suitably high skin temperature, it has proved sufficient for the insert to have a total 0 thickness of just under 1 cm, and since the sheets are extremely light, the heating pad is very pleasant to wear and does not hamper the working ability.It has also to be mentioned that a pattern as the one shown allows an adequate ventilation between the heating 5 pad and the skin, which contributes to the comfort in use. The heating pad according to the invention may, of course, have any shape and size, as it can be intended-BϋREA TOMPI for use in different regions of the body, and it can also form part of garments, e.g. be inserted in the shoulder region, the back and/or the front part of a waistcoat. | Patent Claims1. A heating pad consisting of an envelope 1 pro¬ vided with an insert 2 of insulating material, c h a r a c t e r i z e d in that the insert 2 consists of one or more flexible sheets 3 of plastics material, each sheet having on one face or both a protruding pattern of plastics material consisting of a great number of air- or gas-filled bubbles or small bodies 4.2. A heating pad according to claim 1, c h a r a c t e r i z e d in that the insert 2 consists of a plurality of interconnected thin, flexible sheets3 which, on one face, are provided with a great number of evenly distributed, preferably circular, hollow air- filled protuberances 4 of soft plastics material.REATOMPI _ | MERCATOR REKLAM OCH MARKNADSFO; MERCATOR REKLAM OCH MARKNADSFOERING AB | PETERSEN K |
WO-1979000192-A1 | 1,979,000,192 | WO | A1 | XX | 19,790,419 | 1,979 | 20,090,507 | new | B23Q11 | B24B55, B01D21 | B01D21, B23Q11, C10M175 | B01D 21/00+/10, B23Q 11/10B, C10M 175/04 | METHOD AND ARRANGEMENT FOR CLEANING CUTTING FLUID | A method and an arrangement for cleaning cutting fluid used for metal machining. The cutting fluid is withdrawn from the collecting tank (1) at a metal cutting machine by means of vacuum and conveyed to a central cleaning plant by way of a container (3) connected to a vacuum pump. From the cleaning plant the cutting fluid is returned to the collecting tank (1) at the metal cutting machine. The cleaning plant may with advantage comprise a separation tank (6), where separation takes place by gravity and a centrifugal separator (8). | Me hod and arrangemen or c ean ng cu ng uTechnical fieldThe present invention relates to a method of cleaning cutting fluid usedfer the metal machining, at which the cleaning of the cutting fluid takes place in a central cleaning plant and an arrangement for carrying through the method. The cleaning plant cleans the cutting fluid from a number of collecting tanks.In connection with metal machining cutting fluids have been used since long for lubricating and cooling. The cutting fluid shall cool the tool used for the cutting, the workpiece and the formed chips and reduce the friction by forming a lubricating film between the sliding surfaces. Usually thecutting' fluid contains among all corrosion protecting agents, emulsifiers and bac- tericides. Every metal cutting machine has in a collecting tank a supply of cutting fluid and from the tank the cutting fluid is pumped to a nozzle and sprayed over the workpiece and the tool. When the cutting fluid passes the cutting spot it brings along larger and smaller metal chips. The larger metal chips are sscarated by passing the fluid through some kind of strai¬ ning means, for example a plate or a case provided with small openings, on its way to the collecting tank. The cutting fluid is in addition to the metal chips often contaminated by oil, which spreads as a surface layerover the cutting fluid. In spite of the bactericides a growth of bacteria may take place under the film of oil, which results in very ill-smelling breaking down products. The staff handling the metal cutting machines run the risk of infections on arms and hands as a consequence of the fact that the cutting fluid is contaminated with bacteria, solid particles and oil.Background artEarlier contaminated cutting fluid has been cleaned centrally by conveying the cutting fluid through pipelines in and below the floor to a cleaning plant in connection with a central tank. Contaminants of metal have been separated by passing the cutting fluid through different types of filter. Oil has been removed from the surface of the tank by means ofa bandskimmer. It is very difficult to remove all of the oil without bringing alonga large part of cutting fluid, which makes the method uneconomical.-BUREAU OMPI According to the invention a method and an arrangement for cleaning of cut ting fluid is now proposed which may easily be installed in existing engi¬ neering plants without any expensive changes or rebuildings and which implies that important advantages are achieved for the staff at the metal cutting machines, which no longer have to be exposed to ill-smelling gases and skin irritation by metal chips and oil in the cutting fluid.Disclosure όf_inventionThe method according to the invention .is characterized mainly in that conta minated cutting fluid by means of vacuum is conveyed from the collecting tank at the cutting place to a container, which is connected to a vacuum pump. From the container the contaminated oil is conveyed to a cleaning plant and is thereafter returned to the collecting tank. By sucking thecat ting fluid in this way from the collecting tank to the cleaning plant it i possible to avoid bulky transporting arrangements in and below the floor o an expensive manual handling and also to avoid the use of pumps which may be damaged by the small metal particles which follow the cutting fluid. A cleaning system according to the invention is also very flexible. It may easily be adapted to the location of the cutting machines in the plant and further cutting machines may easily be connected to the cleaning plant. Th cleaning of the cutting fluid may take place continuously when the metal cutting machine is working. It is also possible to suck the cutting fluid the cleaning plant at shorter or longer intervals.According to the method of the invention the main part of the cutting flui is brought to circulate in order to cool and lubricate the tool and the wea piece, while a lesser part of the content in the collecting tank is sucked away and conveyed to the cleaning plant. This indicates that if some error should occur in the cleaning plant there is anyhow enough fluid to make metal cuttin 'possible.In order to convey the cutting fluid back to the cutting place the cleaned cutting fluid is put under pressure, when the cutting fluid has passed the cleaning plant.The contaminated cutting fluid is according to the invention with advantag cleaned by passage through a separation tank. In this separation iahk asepa¬ ration by means of gravity takes place since light contaminants, as oil, collected in the upper part of the separation tank whereas metal chips andOMP heavy contaminants sink to the bottom of the separation tank. ?rom T e sepa¬ ration tank a first fraction containing cutting fluid and light is withdrawn and this fraction is led to a separator, for example a centri¬ fugal separator. The cleaned cutting fluid withdrawn from the separator is together with a second fraction from the separation tank mainly containing cutting fluid conveyed to a second tank in which the collected cutting fluid is put under pressure and returned to the collecting tank at the cutting place. Owing to this combination of cleaning steps an efficient cleaning of the contaminated fluid is obtained with relatively simple means as well as an essential reduction of the amount of bacteria, solid particles and oil in the cutting fluid.According to the invention an arrangement for carrying through the described method of cleaning cutting fluid is also suggested. This arrangement mainly comprises a pipeline arranged to be placed under vacuum, which pipeline at one end opens under the surface in a collecting tank for cutting fluid and in its other end is connected to a container, which in its turn is connected to the vacuum pump. The arrangement also comprises a cleaning plant for con¬ taminated cutting fluid which has been sucked away from the collecting tank • and a second pipeline by the aid of -which cutting fluid is returned to the collecting tank.The proposed arrangement is further preferably provided with a second tank for cleaned cutting fluid, which is connected between the cleaning plant and the second pipeline, which second tank is provided with means in order to put the cutting fluid under pressure.The cleaning plant according to the invention suitably comprises a separa¬ tion tank with a tangential inlet for contaminated cutting fluid and a first outlet for a first fraction comprising cutting fluid and light contaminants and a second outlet for a second fraction consisting mainly of cutting fluid. The first fraction is led to a separator, for example a centrifugal separa¬ tor, and from this a heavy phase containing cleaned cutting fluid and a light phase containing light contaminants are withdrawn. The outlet for heavy phase from the separator and the second outlet of the separation tank are connected to the second tank mentioned above.The separation tank is with advantage designed such that in its centre there is arranged an insertion with walls which inside the insertion define two fluid chambers delimited from the fluid chamber in the separation tank. The_ first of these fluid chambers has an inlei- which consists of a brim inlet from the fluid chamber in the separation tank and an outlet which extends through the fluid chamber in the separation tank. The second fluid chambe has an inlet which is connected to the fluid chamber in the separation ta in such a manner that the same liquid level is obtained both in the sepa¬ ration tank and in the second fluid chamber and an outlet which extends o of the separation tank. Alevel-holding means is arranged to sense the liqu level of the second fluid chamber and supply clean fluid when the level sinks.Brief description_of_drawingsThe proposed method of cleaning cutting fluid and an arrangement for carr ing through this method are described closer with reference to the enclos drawing, figure 1 of which shows a flow chart of a preferred embodiment o the invention and figure 2 of which schematically shows an embodiment of separation tank used for the described embodiment. In the flow chartobvio details like valves have been omitted.Best mode of carrying out the inventionIn Fig. 1 a number of collecting tanks for cutting fluid at cutting machin are shown. From the collecting tanks 1 contaminated cutting fluid is con¬ veyed to a container 3> by way of a pipeline 2. The pipeline 2 may with a vantage be arranged at some height over the metal cutting machines, in th same way as in a pipeline milking plant. The container 3 is connected to vacuum pump 4 and by means of this the container 3 and the pipeline 2 are put under vacuum. At each connection the pipeline 2 ends just below the su face in the collecting tank. The cutting fluid contaminated with oil is sucked on to the cleaning plant, while the heavier metal particles remain the bottom of the collecting tank. From the container 3 the contaminated cutting fluid is conveyed to the separation tank 6 by way of a pipeline __ The inlet for cutting fluid is arranged such that the cutting fluid is giv a tangential movement in the separation tank. Light contaminants are at th gathered near the surface in the middle of the separation tank and from there a fraction is withdrawn which is directed to a separator 8 by way o a pipeline 7- The mixture of cutting fluid, sludge and metal particles, which are separated in the separation tank β, is conveyed to pipeline 7 b way of pipeline 7a. __. the shewn .embodiment of the invention the separator consists of acentri¬ fugal separator but it is also possible to separate light contaminants from the cutting fluid by means of a skimmer, while heavy contaminants are sepa¬ rated by means of filter.Through the light phase outlet 9 of the centrifugal separator .oil and other light contaminants are withdrawn and through the sludge outlet ~a solid con- _ taminats. The obtained heavy phase which contains cleaned cutting fluid is conveyed to a second tank 11 for cleaned cutting fluid by way of a pipeline 10. A second fraction from the separation tank which mainly contains cleaned cutting fluid is also transported to the tank 11 by way of a pipeline 12. The cutting fluid is put under pressure by means which not are shown and returned by way of the pipeline 13 to the collecting tanks 1 at the cutting machine. Also pipeline 13 may be arranged over the machines. The collecting tanks are with advantage provided with, liquid level indicators (not shown in the drawing) in order to hinder that the tanks overflow. There is also a throttling at the inlet of pipeline 2 in order to control the amount of air sucked into the vacuum system (not shown in the drawing) .In Fig. 2 there is shown the separation tank 6 with a tangential inlet 1 connected with the pipeline ~ , In the separation tank β there is also arranged an insertion with two coaxial, cylindrical walls 15, 16 and a bottom 17. In the insertion these walls separate two fluid chambers 18, 19 delimited from the fluid chamber in the separation tank. In this embodiment the insertion consists of two coaxial cylinders but it may of course be de¬ signed in some other way as long as the in- and outlets of the insertion are designed such that the same flow conditions that are described below areob¬ tained. The upper edge 20 of the cylindrical wall 15 is arranged such that the edge is situated just below the liquid level in the separation tank. _ e inlet to the fluid chamber 18 consequently consists of an annular brim inlet over the edge 20. The fluid chamber 18 also has an outlet 21, which extends through the separation chamber and is connected to the pipeline 7« Inside the wall 1β there is a second fluid chamber 19. In this second fluid chamber 19 there is arranged a pipe 22, the lower part of which is fastened to the bottom of the insertion and the upper end of which is situated at the same level as the edge 20. Through this pipe the fluid chamber 19 is connectedto the fluid chamber in the separation tank. In the bottom 17 of the insertion there is also arranged an outlet 25 from the fluid chamber 19 which is con¬ nected to the pipeline 12. A level sensing means (not shown in the drawing) for example a float, is also arranged in the fluid chamber 19, which means-BUREAUOMPIA - >_. wWiIpPoO .»,y 4 c r- actuate a valve 24 in a feed pipe 25 for clean cutting fluid. In the bottom of the separation tank there is also an outlet pipeline 26 for sludge sepa¬ rated in the separation tank, which pipeline is connected to the pdpeli e 7a.The separation tank according to the invention is intended to work in the following way. When the contaminated cutting fluid is conveyed tangentiall into the separation tank light contaminants are gathered in the middle of the tank and flow over the brim inlet into the fluid chamber 18. Heavy con taminants on the other hand sink towards the bottom of the tank and are collected there. Owing to the fact that the inlet to the fluid chamber 1 is arranged on a certain depth in the separation tank the cutting fluidthat is collected in the fluid chamber 19 will be relatively clean.According to the invention the cleaning of the cutting fluid takes place i no less than four steps. The first step consists of the preliminary sepa¬ ration of heavier metal contaminants in the collecting tank, while an uppe fraction of the collecting tank is sucked to the cleaning plant. Step two consists of the passage of the container 3 n which a certain part of the heavy particles are gathered at the bottom of the container, which partLc_---s intermittently are withdrawn from the bottom. Step three consists of the cleaning in the separation tank which is described above. Step four consists of the cleaning in the centrifugal separator from which, apart from the tw liquid phases, a sludge phase consisting of small metal particles is with¬ drawn continuously or intermittently, which metal particles have not been separated in earlier separation steps.According to the invention a reduction of the amount of bacteria is obtaine This effect has also been shown experimentally, since measurements have shown that the amount of bacteria, when cleaning according to the mveition, has diminished from 10 bacteria/ml to 10 bacteria/ml, which is considere as a satisfactory value. That the amount of bacteria has diminished is sup¬ posed to depend on the fact that around the metal particles there is a thin film of oil, in which a growth of bacteria takes place, hen the small metal particles are separated a certain amount of bacteria accordingly follow them.-\_Λ_' EA OMPI | 1. Method of cleaning cutting fluid used for metal machining, at which the cleaning takes place in a central cleaning plant, c h a r a c t e r i z e d in that contaminated cutting fluid is withdrawn from a collecting tank at a metal cutting place by means of vacuum, that the cutting fluid by means of vacuum is conveyed to a container, which is connected to a vacuum pump, that the cutting fluid from the container is transported to the cleaning plant and from this is returned to the collecting tank at the metal cutting place.. Method according to claim 1 , c h a r a c t e r i z e d in that the main part of the cutting fluid is circulated for cooling and lubricating of the tool and the workpiece, while a smaller part of the content in the col¬ lecting tank is sucked away and conveyed to the cleaning plant.3. Method according to claim 1 or 2, c h a r a c t e r i z e d in that the cutting fluid is put under pressure when it is returned from the clea¬ ning plant.4. Method according to claim 1-3, c h a r a c t e r i z e d in that 'the contaminated cutting fluid in the cleaning plant is brought to pass a separation tank in which a separation due to gravity takes place, that a fraction containing cutting fluid and mainly light contaminants is withdrawn from the separation tank and is led to a separator, for example a centri¬ fugal separator, and that the cleaned cutting fluid that is withdrawn from the separator, together with a fraction withdrawn from the separation tank, which mainly contains cutting fluid, is led to a second tank in which the collected cutting fluid is put under pressure and returned to the collect¬ ing tank.5. Arrangement for carrying through the method according to claim 1 , c h a r a c t e r i z e d in that it contains a first pipeline (2) arranged to be put under vacuum which in one end opens under the surface in a collecting tank (l) for cutting fluid and in its other end is connected to a container (3) , which is connected to a vacuum pump (4) , a cleaning plant for contaminated cutting fluid which has been sucked away from the collect¬ ing tank and a second pipeline (13) by means of which cutting fluid is re¬ turned to the collecting tank.6. Arrangement according to claim 5> c h a r a c t e r i z e d in that a second tank ( l) for cleaned c ttin fluid is connected between the clean ing plant and the second pipeline (13). which second tank (11) is provide with means to put the cutting fluid under pressure.7. Arrangement according to claim 6,_ c h a r a c t e r i z e d in th the cleaning plant comprises a separation tank (β) with a tangential inle for contaminated cutting fluid and a first outlet for a first fraction co prising cutting fluid and light contaminants, a second outlet for a secon fraction consisting mainly of cutting fluid, a separator (8), for example centrifugal separator, to which the first fraction is conveyed and from which a heavy phase consisting of cleaned cutting fluid and a light phase consisting of light contaminants are withdrawn at which the outlet for hea phase and the second outlet from the separation tank are connected to the said second tank (11).8. Arrangement according to claim J , c h a r a c t e r i z e d in th in the centre of the separation tank there is arranged an insertion with walls (15, 16) which inside the insertion delimit two fluid chambers (18,1 separate from the fluid chamber in the separation tank, where the first separate fluid chamber (18) has an inlet consisting of a brim inlet from t fluid chamber in the separation tank and an outlet (21) which extends '■ through the separation tank, while the second separate fluid chamber (19) has an inlet (21) which is connected to the fluid chamber in the separati tank in such a way that the same liquid level is obtained both in the sep ration tank and in the second fluid chamber (19) end an outlet (23) which extends out through the separation tank, at which a level-holding means i arranged to sense the level of cutting fluid in the second fluid chamber ( and an outlet (25) which extends out through the separation tank, at whic a level-holding means is arranged to sense the level of cutting fluid in ih second fluid chamber (19) and supply new cutting fluid, when the level sinks.-BURO | ALFA LAVAL AB; LEE H | LEE H |
WO-1979000196-A1 | 1,979,000,196 | WO | A1 | XX | 19,790,419 | 1,979 | 20,090,507 | new | G08B13 | null | G08B13 | G08B 13/26 | PRE-INTRUSION DETECTION DEVICE | An intrusion detection unit is disclosed which comprises a capacitance having an active , field, the coupling of which is significantly increased when an intruder comes into conductive relation with a doorknob. The unit is hung on the inside doorknob and is so arranged that the doorknob is the transmitting element of the capacitor, while a separate plate is the receiving element of the capacitor. The capacitor field is maintained actively charged by a battery driven oscillator which operates at a substantially uniform frequency and amplitude. The intrusion detector circuit is complete in itself and is not externally grounded by the intruder. The signal receiving portion of the circuit incorporates a square law amplifier, and also has means for adjusting the reference level to which the signal is compared. | -1- PRE-INTRUSION DETECTION DEVICE BACKGROUND OF THE INVENTIONThis invention relates to a device for providing a pre- intrusion signal, particularly of the type which warns when an intruder is trying to ,open a door to gain en- try. It is primarily designed to he associated with a doorknob, and to detect the proximity of an intruder's hand to the doorknob. The detected signal can then sound a warning alarm, or actuate any suitable pro¬ tective device. More specifically, I have invented a simple, highly practicable, battery-operated electrical device which can be hung on the inside of the doorknob, and which is fully self-contained, i.e., it requires no elect¬ rical power source or an external ground. Many devices of this general type have been proposed, but the problems inherent in such detection devices have not heretofore been satisfactorily solved. Such devices, as a practical matter, do not provide an adequate intrusion signal unless they are externally connected, thereby losing the benefits and conven¬ ience of a self-contained unit.The prior art devices intended to solve the problem have fallen into two general categoriess (1) Passive devices - which are arranged to pick up electromagnetic or electrostatic fields generated externally, and which respond to the additional antenna effect created by an intruder; or (2) Ground Capacitance devices - which utilize oscillator circuits, and which exper¬ ience altered circuit values when an intruder estab- lishes an external capacitance relative to an external earth ground. Of the two prior art types, the ground capacitance devices appear to be more numerous. The prior art devices of the ground capacitance type are represented by the following U.S. patents: Bagno■ W'ϊrr' 3,199,096; Fontaine 3,623,0635 Do in et al 3,697,971; Gehman 3,706,982; Atkins 3,735,379; Guetersloh 3,829, 850; Bolle et al 4,021,679; and Tanaka et al 4,030,037. The intrusion-detection systems of each of the listed patents share certain attributes. They each rely on an external ground capacitive effect which occurs when the intruder is physically coupled to the oscillator. Also they each use changes resulting from such extern¬ al ground capacitive effect to alter internal circuit values, such as oscillator output levels or frequen¬ cies, thereby causing an output signal. In such sys¬ tems, the human capacitance represents a capacitive loading on the oscillator. The prior art devices of the passive type are repre- sented by U.S. patents Dettling et al 3,771,152 and Geiszler et al 3>956,7^3* A device of this type relies on the antenna effect of an intruder in causing a change in the received signal from an electromagnetic or electrostatic field. The detector signal increases because the intruder constitutes, in effect, an ex¬ tension of the antenna, which is receiving passively the pickup from the field. In other words, the device functions by detecting the change in the charge on the antenna. Both of the types of intrusion detectors discussed a- bove have serious functional problems. They can oper¬ ate satisfactorily if they are externally connected, or grounded, e.g., if they are plugged into an avail¬ able electrical system. But it is important, as a practical matter, that the detector unit be self-con¬ tained.When such prior art detectors are self-contained, they inherently have very weak signal changes to respond to. This is true because, whether the intruder forms an antenna or a capacitor, the himan effect represents a very small addition to the existing antenna or to the existing capacitance. This is particularly serious in view of the wide range of doorknobs, metallic door frames and metallic ornamentation commonly associated with door openings. The change in signal level caused by the intruder is relatively small, substantially less than 5% of the total signal level, and it is very difficult to detect reliable. Where the device is battery-operated, the reference to earth ground is' substantially non-existent, and can on¬ ly be described as a.' current leakage; thus increasing the problem of small signal change detection.. In other words, the grounding required to complete the circuit, of which the intruder forms a part, exists only to the extent of leakage; and the intrusion signal is thus minimized by the high impedance of that circuit. - As discussed in several of the prior art patents, noise is a significant problem in units which function by using a change in capacitance to vary the frequency or amplitude of an oscillator. The extraneous causes of signal changes, such as temperature change, humidity change, household 6θ-cycle current, ets. , can cause spurious detector responses. This results in part from the weakness of the detected intrusion signal, and in part from the fact that the presence of noise causes the oscillator to change frequency or amplitude. In the light of the deficiencies in prior art devices, and after extensive experimental efforts, I have con- eluded that, in order to have a successful battery-op¬ erated device for detection of a human contact with, or proximity to, a doorknob, it is necessary to gen¬ erate and detect a strong signal by relying on a ground system within the detection instrument itself,WREAZO PI - -thereby avoiding the necessity of working with a very small signal limited to a leakage path to earth ground. SUMMARY OF THE INVENTIONTo obtain the result just discussed, I have invented an intrusion detector -incorporating a fundamentally differ¬ ent concept. A capacitance effect is used to detect in¬ trusion but the capacitor is complete within the self- contained circuit of the detector. The detector circuit includes a capacitor formed by a transmitting element and a cooperating receiving element, the transmitting element being driven by a suitable os¬ cillator, shich maintains a stable frequency and ampli¬ tude. One of the capacitor elements, preferably the transmitting element, is electrically in contact with the doorknob, so that an intruder's hand on or near the doorknob significantly increases the coupling of the capacitor. This results in the transfer of a substantial¬ ly increased signal to the capacitor receiving element, • which causes actuation of a protective device, such as an alarm.The effect of the intruder's touching the doorknob is to enlarge the size of the transmitting element and/or to decrease the distance between the transmitting and receiving elements of the capacitor. If the transmit- ting and receiving elements are spaced apart sufficient¬ ly, the normal capacity between them is low and gener¬ ates a weak electrostatic field. This field is sub¬ stantially increased when an intruder touches the door¬ knob, causing a signal change to be generated which may be in the neighborhood of 20 of the original signal, as compared to a signal change of, say, 2% in the prior art devices.BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an elevation view, partly in cross-section,-BUROM, A> showing my intrusion detecting unit mounted on a door¬ knob;Figure 2 is. a block diagram showing the components Of the electrical circuit of the intrusion detecting unit; Figure 3 is a schematic diagram showing, the electrical circuit in greater detail;andFigure 4 is a graphic representation of the electrical signals at various stages in the circuit of the pre- ceeding figures. DETAILED DESCRIPTION OF PREFERRED EMBODIMEN {In Figure 1, a doorknob having an outer knob 11 and an .inner knob 13 is shown extending through a door 15. Hanging from the inner knob 13 is a self-contained, battery-operated intrusion detector unit 17. The unit 17 is suspended from the inner knob by a metallic chain 19, which constitutes a conductor between the circuitry of the unit and the metallic doorknob. Within the unit 17 are a battery 21, a capacitive receiving element 23, a printed circuit board and electronic assembly 25, and an alarm 27.As will be discussed in greater detail later, a funda¬ mental aspect of this intrusion detector unit is the reliance on an internal capacitance, which is charged by an oscillator to create an electrostatic field, and which is caused to develop a significant signal change when an intruder contacts, or comes into proximity with, one element of the capacitor.The two elements of the capacitor are the doorknob 11- 13 and the plate-like metallic element 23. Although either of the two capacitor elements could constitute the transmitter, with the other functioning as the re¬ ceiver, I have found it convenient to use the doorknob as the transmitting element of the capacitor and the element 23 in unit 17 as the receiving element of the capacitor. The transmitting and receiving elements could also be variously described as conductors, as capacitor plates, as antennas, or al transmitting and receiving electrodes. Figure 2 shows the basic circuit components. An oscil¬ lator 31, which is powered by battery 21, is electrical¬ ly in contact with the doorknob 11-13 via metallic chain 19. The oscillator 31 drives the doorknob as the transmitting element of the capacitor, thereby generating an electric field between the doorknob and the receiving element 23- The receiving element 23 of the capacitor responds to the strength of the electro¬ static field, or capacitance, between itself and the doorknob. The field signal from receiving element 23 is fed to an amplifier 33 which sends the amplified signal to a de- tector-and-filter 35, which yields a DC signal pro- ■ portional to the incoming signal. A voltage comparator 37 compares the incoming signal with a reference level, and provides an OFF/ON signal which triggers a bell os¬ cillator 39 when an intruder's presence is detected. Triggering of the bell-oscillator 39 causes an alarm 41 to sound, and to continue sounding, as long as, and whenever, an intruder is touching or almost touching the doorknob.Figure 3 shows diagramatically the details of the cir¬ cuit. The oscillator 31 s preferably a square wave os¬ cillator because the high level of harmonic signals thus generated will constitute a stronger signal and will be received and detected more easily. The oscil¬ lator 31 is shown as an operational amplifier config¬ ured as a square wave oscillator, and buffered by an inverter ^3. This buffering causes the oscillator to provide a consistent signal, not affected in eitherBUOM frequency or amplitude by what occurs in the subsequent circuitry. This aspect is directly contra to most prior art devices, which rely on changes in the frequency and/ or amplitude of the oscillator to trigger the intrusion warning. The frequency of the oscillator 31 should be selected to minimize noise interference, such as 60- cycle noise.The signal from the buffered oscillator 31 is fed by chain 19 to doorknob 11-13, where it develops an electrostatic field between the doorknob, as the trans¬ mitting element, and the receiving element 23• The re¬ sulting signal from element 2 is fed to an operation¬ al amplifier 33 configured as a DC amplifier, which is preferably a square law ampli ier in order to enhance discriminability. With a square law amplifier, the change in received signal is augmented as a function of X . For a signal difference of a ratio of 2/l, square law amplification yields a ratio of 4/1, thus providing a substantially greater signal change than could be obtained by linear amplification and detect¬ ion. This is accomplished without additional power drain.The signal from amplifier 33 is then rectified and filtered by detector filter 35 and isolated by an op- erational amplifier 45 configured as a voltage fol¬ lower. The signal then is fed to voltage comparator 37, where it is compared with a reference signal 7• The reference signal 4 is variable so that it can be man¬ ually adjusted to provide optimum functioning of the intrusion detecting device.When an intruder touches the doorknob 11-13, the coup¬ ling between the doorknob transmitting element and the receiving element 23 is increased, thereby increasing the signal levels at the amplifier 33, detector-filter-BUREΛITOMP1 wipo Ay 35, and buffer 45. Thus the comparator 37 is driven high and an inverter 49 is driven low, which starts operation of the bell oscillator 39. The bell oscil- ■■ lator 39 drives a Darlington pair 51 high and low in alternating sequence. An alarm 53 n the emitter cir¬ cuit of the Darlington pair is activated in an altern¬ ating sequence.Figure 4 shows graphically the stages in the signal generation of the intrusion detector device. The left side of the figure represents the normal signal level and the right side of the figure represents the signal level when a person is touching the doorknob. Line A in the figure shows the square wave signal generated by oscillator 31, which remains constant in frequency and amplitude.Line B represents the signal received by the receiving element 23, which responds to the electrostatic field between it and the transmitting element, doorknob 11- 13- The received signal amplitude B is dependent on ■* the distance apart and on the relative size of the transmitting and receiving elements. When the doorknob is touched, the received signal is increased as shown. Line C represents the amplified signal from amplifier 33; and Line D represents the rectified and detected signal from detector-filter 35- The resulting signal drives the voltage comparator 37- When the rectified signal exceeds the variable (adjustable) reference lev¬ el signal 47, the signal of comparator 37 goes high , as represented on Line E; and the signal from inverter 4 goes low , as represented on Line F. This starts the bell oscillator 39, which produces an alternating signal, as shown on Line G. This alternating signal is fed to the Darlington pair 51, which drives the alarm, as represented on Line H. The operation of my intrusion detecting device is doubt¬ less abundantly clear at this point, but a brief recap¬ itulation is in order, coupled with a summary of the primary features and advantages. The battery, oscillator, and capacitor (which includes the doorknob and the metallic receiving element) are included in a self-contained, complete-in-itself cir¬ cuit, which is not grounded externally at any time. The oscillator drives the transmitting element (the doorknob) of the capacitor, thereby creating and maintaining an active electrostatic field between it and the receiv¬ ing element. The power requirements are small because current is needed only to charge the capacitor. The os¬ cillator output is maintained constant in frequency and amplitude, thereby minimizing noise problems which tend to result if the oscillator signal is not coherent. The signal received by the receiving element of the cap¬ acitor is amplified and detected downstream. When an in¬ truder reaches for the doorknob, the coupling, or cap- acitance, between the transmitting and receiving ele¬ ments of the capacitor is very significantly increased, because the intruder's body enlarges the size of the transmitting element and/or decreases the distance be¬ tween the transmitting and receiving elements. This relatively large increase in coupling in the capacitor causes an easily detectable change in the received sig¬ nal, which is amplified, detected, and used to trigger an indication of the intruder's presence. The sensitiv¬ ity of the alarm is adjustable by the user, who can vary the reference signal level by moving a manual con¬ trol element.The coupling effect of the intruder on the capacitor directly triggers the alarm without affecting the os¬ cillator. The receiving element of the capacitor sees JUREAI OMPI the change in signal amplitude due to the coupling ef¬ fect. The normal coupling of the transmitting and receiv¬ ing elements, when an intruder is not present, could be characterized as a loose coupling. The intruder causes this coupling to tighten up, and this change direct¬ ly triggers the alarm.It is my view, based on the developmental work in con¬ nection with this invention, that the herein described device is the only practicable means of providing a doorknob intrusion alarm, if the device must be bat¬ tery driven and if it must be isolated from an extern¬ al grounding field. This results primarily from the very substantial increase in the signal change caused by the intruder's presence; and this in turn is due to the functional difference between devices in which the in¬ truder is part of an external, high resistance ground¬ ing system and the present device, in which the in¬ truder increases the capacitive coupling in an intern¬ ally-grounded circuit. Another bebefit results from the noise avoidance which is permitted by the use of a stable oscillator, the values of which are not altered to activate the intrusion detector. Since the transmit¬ ted and received signals are coherent in phase and frequency, external noise has an insignificant effect. The following claims are intended not only to cover the specific embodiments disclosed, but also to cover the inventive concepts explained herein with the maximum breadth and comprehensiveness permitted by the prior art.-BUR O. A, | CLAIMS1. A self-contained intrusion detector unit comprising: means for generating alternating electrical energy powered by a source within the detector unit; means driven by said generating means for transmit¬ ting into an electrostatic field; means capacitively coupled to said transmitting means for receiving electrical energy from said electro¬ static field; the capacitive coupling effect between said- trans¬ mitting means and said receiving means being altered by the presence of an intruder in proximity thereto; and means responsive to such alteration of the capaci¬ tive coupling effect to provide an intrusion signal.2. The intrusion detector of Claim 1 which also comp¬ rises, means for adjusting the sensitivity of the in¬ trusion signal response to alteration of the capacitive coupling effect.3. The intrusion detector of Claim 1 wherein the pre¬ sence of an intruder alters the capacitive coupling ef¬ fect between the transmitting means and the receiving means without coupling to earth ground.4. An intrusion sensing electrical circuit comprising: means for providing an electric field comprising transmitting and receiving elements; means for driving the transmitting element to main¬ tain an active electric field; and means for changing the effect of the electric field on the receiving element when an intruder comes into electrical conducting relation with one of said elements. 5. The intrusion sensing circuit of Claim 4 wherein there is no external grounding even when an intruder is present.6. The intrusion sensing circuit of Claim 4 wherein the transmitting element includes a doorknob.7. The intrusion sensing circuit of Claim 4 wherein the driving means is an oscillator which operates at a substantially uniform frequency and amplitude.8. That method of detecting the proximity of an intrud¬ er to a doorknob which comprises: establishing and maintaining an electrostatic field between two spaced conductive elements in a self-con¬ tained circuit, one of which elements is in conductive relation to the doorknob; receiving a signal change from said field when an intruder is in conductive relation with the doorknob; and converting said signal change into an indication of the intruder's presence.9. The method of Claim 8 wherein the coupling between the two conductive elements is increased whenever an intruder is in conductive relation with the doorknob.10. A complete-in-itself intrusion detecting device de¬ signed to be suspended from an inside doorknob compris¬ ing: a metallic transmitting element which constitutes part of an active capacitance, and which includes the doorknob; a battery-powered, continuously-transmitting oscil-^OMA W1 lator in conductive relation with the transmitting el¬ ement and arranged to charge the electrostatic field of the capacitance; a metallic receiving element which constitutes part of the active capacitance and which is spaced suffic¬ iently from the transmitting element to provide norm¬ ally a weak although active electrostatic field; the capacitive coupling and signal level between said transmitting element and said receiving element being increased significantly by an intruder coming into con¬ ductive relationship with said doorknob; signal-receiving means for amplifying and detecting the signal level received by said receiving element; and intrusion-indicating means responsive to the signal level from the signal-receiving means to provide an in¬ dication of intrusion when said signal increases to a level higher than a reference signal.11. The intrusion detecting device of Claim 10 wherein the oscillator is a square wave oscillator which is buf¬ fered from the capacitance to insure substantial uni¬ formity in the frequency amd amplitude of its output.12. The intrusion detecting device of Claim 10 wherein the presence of an intruder changes the signal level without causing a coupling to earth ground.13* The intrusion detecting device of Claim 10 wherein the signal-receiving means includes a square law ampli¬ fier to provide signal difference augmentation without power drain.14. The intrusion detecting means of Claim 10 wherein the intrusion-indicating means includes means for ad-IJUREOMPI justing the voltage level of the reference signal, thereby varying the sensitivity of the device.ϊΛJRO■ , wi | SWEENEY J | SWEENEY J |
WO-1979000202-A1 | 1,979,000,202 | WO | A1 | XX | 19,790,419 | 1,979 | 20,090,507 | new | F22D5 | F22D5 | F22B35, F22D5, F22D11 | F22D 11/00, F22D 11/06, R01K 136/06 | METHOD AND APPARATUS FOR FEEDING CONDENSATE TO A HIGH PRESSURE VAPOR GENERATOR | A mechanical arrangement to reduce drastically the energy consumption for pumping condensate to feed high pressure vapor generators for power generation, industrial processing, and heating systems. Involved is a method to pump the condensate into one condensate receiver (6) located at the suction side of the condensate feed pump (3), and to bleed high pressure vapor from the vapor generator (202) into the condensate receiver (6) for imposing a pressure head upon the condensate therein to be approximately the same as that in the generator (202), and thus the pressure difference between the suction side and the discharge side of the pump (3) is drastically reduced while pumping the condensate into the generator (202), with the result that the energy consumption of the pump (3) is also drastically reduced. The receiver (6) is full of high pressure vapor while the condensate therein is drained by the pump (3), and the high pressure vapor means energy. Further new methods are involved to reduce the vapor pressure in the receiver (6) by returning the vapor to the system or to utilize it, as disclosed in the application. Generally speaking, at least two closed receivers (5, 6) operated in series are required for the method of restoring the vapor in the receivers (5, 6) to the generator (202) after the condensate is pumped into the generator (202). The invented receivers (5, 6) are also designed for condensate heating with almost no energy consumption. | METHOD AND APPARATUS FOR FEEDING CONDENSATION TO A H IGH PRESSURE VAPOR GENERATORThis invention relates to methods and apparatus for feeding condensate to a high pressure apparatus such as a vapor generator, and more specifically, the invention relates to methods and apparatus for feeding condensate to boilers, nuclear reactors, and heat exchangers.There are basically only two ways to solve the current energy crisis. The first is to increase energy sources, and the second is to reduce energy consumption. This invention is concerned with practical applications of the latter.The traditional method of returning condensate to a high pressure vapor generator is by pumping against the pressure head in the generator with a higher pressure head cf the feeding pump. This consumes much energy, as for example, a steam turbine power plant with a steam boiler of 2,4000 psig. pressure usually uses two pumps in series to feed the condensate into the boiler. The first pump pumps the condensate through a series of heaters into a deaerating tank, and the second pump pumps the condensate into the boiler, usually the end of the suction pipe cf the second pump is i the deaerating tank, and usually two additional heaters are empoloyed between the second pump and the boiler tank. The second pump requires more than 2,700 psig. pressure head to overcome the pressure head in the bciler, the friction loss in the heaters and piping, and the water head due to the difference in level between the water level in the boiler and the water level in the suction side of the second pump.An obj ct of this invention is to reduce greatly the power used to pump the condensate to the high pressure vapor generator by utilizing the techniques herein dis¬ closed.Other objects, uses, and advantages will be ob¬ vious or apparent from a consideration cf the following detailed description and the application drawings in which like reference numerals indicate like parts thrσghout the several views.In the drawings : Figure 1 is a diagrammatic representation of an energy saving condensate feeding system in accordance with the invention;Figure 2 is a diagrammatic elevational and sectional view of one of the basic energy saving conden- sate receivers which is usually connected to the last feeding pump, in accordance with the invention;Figure 3 is a view similar to that of Figure 2 illustrating the other basic energy saving condensate re¬ ceiver used in accordance with the invention; Figure 4 is a fragmental alevatiσnal view of a liquid fluid sprinkling arrangement employed in the re¬ ceivers of Figures 2 and 3;Figure 4A is a diagrammatic sectional view taken substantially along line 4A--4A of Figure 4; Figure 5 is a view similar to that of Figure 1 showing a modified arrangement of the embodiment of Figure 1;Figure 5A is a fragmental view showing a varia¬ tion in the embodiment of Figure 5; Figure 6 is a view similar to that of Figures 1 and 5, illustrating a further form of the invention em¬ ploying three of the indicated condensate receivers; andFigure 7 is a view similar to that of Figure 1 illustrating yet a further embodiment of the invention employing multiple pressure vessels.However, it is to be distinctly understood that the specific drawing illustrations provided are supplied primarily to comply with the requirements of the Patent Laws, and that the invention is susceptible of modificatioO that will be obvious to those skilled in the art, and that are intended to be covered by the appended claims. Preferring to Figure 1, the condensate feeding system A of this embodiment comprises condensate receiv- ers 5 and 6 that are constructed in pressure vessel form from suitable material, such as steel, that will withstand internal pressures of up to 8,000 psig., depending upon the operating pressure. In situations where the quantity of oxygen in the processed fluid is enough to cause rust, stainless steel having a thickness in the range of from approximately 1/8th inch to approximately 1/2 inch can be used at all wetted parts of the receivers or vessels, as well as the inner surfaces of the piping employed in con¬ nection with the same. Stainless steel piping and fittings can be used wherever it is financially feasible. All valves, except check valves, shown in Figure 1, 5, 6 and 7 are of the gradually opened automatic type, -other automa¬ tic or manual valves can be employed in parallel with any such automatic valve as a standby valve in case of e er- gency. One shut off valve shall be installed at each side of an automatic valve.A condensate feed line 25 connects to the re¬ ceiver 5 near its top and contains a check valve 100. A pump 1 in the feed line 25 is operative to pump condensate to the receiver -5 from a suitable source, such as vessel 200 (the condensate in vessel 200 being supplied, for in¬ stance, from steam operated turbines utilizing system A). A vent line 26 extends upwardly from the top of the receiver 5 and contains a check valve 112 and a shut off valve 12. A branch line 32 extends from the line 26 to make available processing vapor for external work. The line 32 contains a shut off valve 20 and a check valve 120. The check valves 112 and 120 prevent fluid flow back into the vessel 5. A condensate discharge line 27 leads from the bottom of the receiver 5 (at fitting 27A, see Figure 2) to the receiver 6 near the top thereof for feeding condensate into receiver 6. The line 27 contains a shut off valve 15 and a check valve 115. Fluid (vapor, con- densate, or both) , inlet line 29 connects to the top of the receiver 6 and discharges into a distributor means which will be described hereinafter. The line 29 is supplied with fluid either from vapor generator 202 (re¬ presented by square) through the line 33 or with heating fluid through the line 34. These lines contain the re¬ spective shut off valves 16, 17, and check valves 116, 117, respectively.A vapor discharge line 31 extends upwardly from the top of the receiver 6 for carrying vapor to the line 28. The line 31 contains shut off valve 14. The line 28 connects to receiver 5 near the bottom of same and serves to provide a way to equalize the pressures between re¬ ceivers 5 and 6.A branch line 35 extending from the line 31 serves as a source to supply vapor from receiver 6 to other processing equipment. Line 35 contains shut off valve 19 and check valve 119. Line 28 extends outwardly, as at 36, from the point where it connects line 31: line 36 connects to a source of heating fluid which may be vapor, condensate or a mixture of both (such source can be a turbine discharge in some cases) . Line 36 extends from line 28 and contains shut off valve 13 and check valve 113 which permits flow only in the direction toward the receiver 5 from the indicated source of heating fluid. Each of the lines 34, 35 and 36 for purposes of disclosure is intended to represent one fluid pipe or multiple fluid pipes in parallel, and each of the said multiple pipes are to contain a shut off valve and a check valve identical to those shown for the respective lines 34 , 35 and 36 .Line 37 extends from the bottom of the receiver 6 (as from fitting 37A, Figure 2) to pump 3 which pumps condensate from the receiver 6 to the vapor generator 202. 5 Line 37 contains shut off valve 18 and check valve 118, the latter permitting flow only in the direction from the receiver 6 to pump 3. Referring now to Figure 2, which shows a de¬ tailed section through the receiver 6 , it will be noted 0 that the line 29 connects at fitting 29A to a vertically disposed distributor tube 40 having multiple openings 41 in the lower part of same. The lower end of the tube 40 is sealed and secured to the bottom of the vessel forming receiver 6 by means of suitable supports 42. The primary 5 liquid level, indicate'd at 43, represents the lowest level to which the vessel or receiver 6 is to be filled with condensate. The line 31 (Figure 1) connects with fitting 3LA of the receiver 6, and the fitting 37A at the bottom of receiver 6 connects with line 37 (Figure 1). A dis- 0 tributor 44 extends horizontally across the receiver 6 at the upper part of same and connects to the line 27 through the fitting 27A. Each of all said fittings is a fitting of an opening of the shell 203. The distributor 4-4 is in the form of tube 44A having a multiplicity of holes 45 formed 5 in same about its circumference, within receiver 6. The receiver 6 also has affixed to its upper end one or more sprinkler devices 54 (see Figures 2, 4 and 4A) ; each device 54 comprises a trough 54A having a multiplicity of holes 55 formed in and along the lower portion of same 0 through which condensate supplied to sprinkler 54 is to flow by gravity to condense heating vapor above level 43 in order to reduce the vapor pressure in vessel 6. The troughs 54A extend across the receiver and have their ends 56 suit¬ ably affixed to the receiver so that all condensate supplied to same drains out through holes 55. Condensate is supplied to the troughs 54A by their receiving condensate sprayed upwardly through distributor 44 when condensate is forced to distributo'r 44. Alternately, troughs 54A may be replaced by tubes or containers connected to an opening in the receiver shell. The tubes or containers have vent openings at the top and multiple holes at the bottom for sprinkling. The sprinklers can be made of aluminum or stainless steel to meet the requirement of each application. The distributor tubes 40 and 44 are made of stainless steel or extra hard tungsten alloy or equiva¬ lents so that they will adequately handle any pressurized fluid passing through the openings of same. They may be suitably fixed within the vessel 6 in their indicated positions. All parts inside the receiver should be so fastened to the wall of same in such a way that maximum expansion can be absorbed without causing any damage. The horizontal tube type distributor 44 can be supported by a larger drainable tube welded to the said wall. The end of the distributor is inside said drainable tube for free expansion. It is important that the outlet openings 41 in the distributor 40 be located below the primary liquid level 43 of the condensate in the receiver 6. Receiver 6 may contain two or more such distributors 40,' as desired. The distributors 40 and 44 are arranged so that the only outlet for the vapor supplied to the re¬ ceiver is through the openings 41 and 45.Receiver 6 is basically defined by encompassing wall structure 203 suitably sealed and reinforced to withstand the operating pressure of any particular case. The receiver 5 (Figure 3) has a pair of hori¬ zontally disposed vertically spaced, tubular distributors 46 and 48 that contain openings 47 and 49 respectively-W.4, distributed along the entire length of the respective distributor tubes 46 and 48 within receiver 5. The distributor tube 46, which is of the same general type as distributor 44 (Figure 2) , is connected with line 25 through fitting 25A. Distributor 48 located adjacent the bottom of the vessel forming receiver 5 is a tube similar to distributor 44 and is connected with the line 28 through the fitting 28A. Line 26 is connected with the fitting 26A at the top of receiver 5, and the line 27 is connected with the fitting 27A at the bottom of receiver 5. Receiver 5 is also equipped with one or more of the sprinkler devices 54 that are operably associated with distributor 46 in the same manner as with distributor 44 of receiver 6. Receiver 5, like receiver 6, is basically de¬ fined by encompassing wall structure 205 suitably sealed and reinforced to withstand the operating conditions con¬ templated by any particular application. Thermal insula¬ tion is required outside the wall 205. It will be apparent that the vapor and conden¬ sate distributors shown in Figures 2 and 3 may be of other suitable distributing shapes that will effect adequate dispensing of the fluids involved within the respective vessels for purposes of condensing the vapor in same. ' In operating the system shown in Figure 1, the condensate accumulating in the equipment involved (for instance, a condensate tank), represented by vessel 200, and which is to be supplied to the vapor generator 202 by the practice of the invention, is pumped by the pump 1 from the vessel 200 through the line 25 into the distri¬ butor 46 of receiver 5. The condensate passes through the distributor openings 47 into the chamber 206 defined by wall structure 205 to fill the vessel 5 up to the primary liquid level 43A. An automatic air vent arrangement of aO PI suitable type is provided for receivers 5 and 6; same air vents are arranged to automatically release the air con¬ tained within the receivers 5 and 6 when the receiver in¬ volved is being charged with condensate in the first operating cycle. This may be done in any suitable manner. After the first cycle the receiver 5 is filled with vapor and then the receiver 5 is charged with condensate. The relatively cooler condensate shall cool the vapor through the distribution of distributor 46, and thus both the vapor pressure in the receiver and the pumping energy consumption are reduced.When the liquid level 43A is reached in receiver 5, pumping is discontinued, and this may be achieved by employing a timer or suitable sensing device la which operates to discontinue the pumping action of the pump 1 when the level 43A is reached.The heating fluid which may be steam at 270 degrees F. , is introduced into the condensate now within the vessel 5 through line 28 and the perforated tube 48, and valve 13 is closed. The temperature of the condensate within receiver 5 will thereby be raised for example from approximately 180 degrees F. to approximately 215 degrees F. During the filling of the receiver 5 and the heating of the condensate, the valves 12 and 20 are closed so that no liquid or vapor escapes from the receiver 5. The valve 12 is opened briefly (about two seconds) to release to the atmosphere air trapped in receiver 5, when the condensate reaches approximately 215 degrees F.After the condensate of receiver 5 has been heated to approximately the temperature level indicated and trapped air has been released, valve 14 is opened to balance the pressures of receivers 5 and 6 (except for the first operating cycle of the system there is high pressure steam remaining in receiver 6 from the previous cycle) ; the valve 15 is opened, and the condensate flows by gravity from the receiver 5 through line 27 into receiver 6, and specifically, through its distributor 44. The condensate is discharged through the distributor openings 45 into the chamber 207 defined by wall structure 203 of receiver 6. During the flow of condensate through the line 27, the valve 14 of line 31 is opened so that the pressure of receivers 5 and 6 remains equalized. After the con¬ densate in receiver 6 reaches the level indicated at 43, the receiver 6 is isolated from receiver 5 by closing the valves 14 and 15. Heating fluid, for example, in the form of steam at approximately 320 degrees F. is then introduced into the condensate in receiver 6 through lines 34 and 29, by opening valve 16, and it discharges into said receiver 6 through its tube 40 and its openings 41. By this procedure the temperature of the condensate in vessel 6 is raised, for example, from approximately 240 degrees F. to approximately 280 degrees F. During this period the valves 17, 18 and 19 remain closed. Valve 20 shall be opened to release vapor from receiver 5 for outside processing after said receiver is drained. This reduces the pressure inside receiver 5, and thus reduces the power requirements of pump 1.To equalize the vapor pressure between the vapor generator 202 and the receiver 6, vapor from the vapor generator 202 is bled into the line 33 by opening valve 17. This high pressure vapor passes into tube 40 and is dis¬ charged through the openings 41 in the tube 40 and imposes on the condensate in vessel 6 a pressure approximately equal to that existing within the vapor generator.It is understood that the high pressure vapor is not limited by its source. It can be bled from any adequate source, and it can be bled into the receiver with¬ out passing through a distributor to impose a vapor pressure in said receiver.It is now possible to pump the heated condensate from the vessel 6 to the vapor generator 202. At this point, the valve 18 is opened and the pump 3 is actuated to pump the condensate into the vapor generator 202, directly or indirectly.After the receiver 6 has been drained, valves 17 and 18 are closed and the valve 19 may be opened to releast vapor from the receiver 6 for external work of any useful character.System A as shown in Figure 1 may be operated in continuously repeating cycles of the type indicated to convey condensate from the receiver 200 to vapor genera¬ tor 202. Lines 35 and 32 and the related valves can be omitted in some cases.Referring now to Figure 5, a system B is illus¬ trated-that is similar to system A except that a pump 2 is utilized in the line 27 to replace the shut off valve 15. This facilitates moving the condensate from the receiver 5 to receiver 6 at a faster rate than that afforded by gravity. The reference numerals of Figure 5 that are identical to those of Figures 1 to 4 indicate like parts. Figure 5A shows that pump 3 pumps the condensate to ' pressure vessel 204 and said condensate is charged from vessel 204 to the generator.Referring to Figure 6, the system C, is similar to that of Figure 5 except that an additional receiver 4 that is arranged in the same manner as receiver 5, has been added. Line 32 in this embodiment connects line 26 at the top of receiver 5 to the lower portion of receiver 4 at its fitting which corresponds to fitting 28A of receiver 5. The pump 1 pumps condensate through the line 25 into the receiver 4 up to the primary liquid level of same. A distributor 48 such as the one. shown in Figure 3 is used to distribute the vapor to heat the condensate in receiver 4. The vapor in receiver 5 is the left over vapor from the previous cycle when said receiver is drained and isolated. The temperature of the condensate may be raised, for example, from about 100 degrees F. to about 130 degrees F. in vessel 4. The pump 2 in line 25 pumps condensate from vessel 4 to vessel 5 through check valve 100 and fitting 25A. Apart from these differences, the operation of the apparatus shown in Figure 6 is the same as that described for the apparatus shown in Figure 1.The operating systems shown in the drawings can be used in fossil and nuclear fueled power or industrial plants. The selection of the specific arrangement em¬ ployed should be based on the particular applications in each case. The word condensate refers to steam conden¬ sate or the condensate of any other vapor as the motive fluid, whenever it is applicable.In the case of utilizing the method involved in the apparatus shown in Figure 5, in a steam turbine fossil fuel power plant with a steam generator of 2,400 psig. pressure, steam is extracted from the turbines in six stages in which the steam temperature of the extract is approximately 150 degrees F., 190 degrees F. , 240 degrees F. , 380 degrees F., 460 degrees F. , and 540 degrees F. During the operation, the vapor retained in the condensate receiver 6 should be approximately at 2,400 psig. pres¬ sure immediately after the receiver 6 is drained. Pump 1 can be used to pump condensate from a condenser, a deaerating tank, or a heat exchanger. For purposes of description, it is assumed that pump 1 is connected with condenser 200, and the pump 1 is to pump condensate at approximately 90 degrees F. from the condenser 200 into the receiver 5, up to the indicated predetermined water level 43A. A pre-set timer or float switch la is employedOMPI. A, WIPO v in the controls for pump 1 to shut off pump 1 when level 43A has been reached. Valve 13 represents three automatic valves in parallel and each valve with a check valve 113 is in separate piping. All three pipes are as shown as line 36; each pipe is connected to a source of steam extract. The first valve 13 is operated to release steam at 150 degrees F. into receiver 5 to heat the condensate in same up to approximately 130 degrees F. , and the second valve 13 releases 190 degrees F. steam into receiver 5 to heat the condensate up to approximately 170 degrees F. ; the third valve 13 releases steam at approximately 240 degrees F. to heat the condensate of receiver 5 up to approximately 210 degrees F. ; then all the. three valves 13 are closed. Valve 12 is open for approximately two seconds to release trapped air in the vessel 5 to the atmosphere.Valve 14 is operated to release steam at not more than 2,400 psig. (received from generator 202 in previous cycle) from the receiver 6 into receiver 5 through a line 28, 31 and distributor 48, and this heats the con¬ densate of vessel 5 up to approximately 300 degrees F. At this point, the vapor pressure in both receivers is balanced. While valve 14 remains open, in the form of Figure 5, pump 2 -pumps the condensate from receiver 5 into receiver 6. Valve 14 and pump 2 is shut off when the receiver 5 is drained.Valve 16 represents three automatic valves 16 in parallel in the manner similar with valve 13. The lines 34 are connected to sources of steam extract. When the condensate has completely been transferred to receiver 6, and said receiver is isolated, the first valve 16 of this series is open to release steam of 380 degrees F. into vessel 6 to heat the condensate of receiver 6 up to approximately 340 degrees F. , and the second valve releases stea of 460 degrees F. to heat the condensate up to approximately 420 degrees F. The third valve releases steam of 540 degrees F. to heat the condensate up to approximately 500 degrees F. ; all three valves are then shut off. Such steam is released to the condensate through distributor 40 (Figure 2) .Valve 17 is opened to release the superheat or saturate steam from the steam generator 200 at 2,400 psig. into the receiver 6 through distributor 40 and to raise the pressure in the receiver 6 up to approximately 2,400 psig. Valve 18 is then opened, and the pump 3 pumps the heated and pressurized condensate in receiver 6 into the steam generator 202, while valve 17 remains open. Valves 17, 18, and the pump 3 are shut off by a suitable pre-set timer arrangement immediately after the receiver 6 is drained. Valve 19 may be opened at this point for re¬ leasing a portion of the steam now present in the vessel 6 for use in supplying steam for other processing needs, and the valve 19 shall then be closed. Valve 20 may also be opened for approximately 2 to 4 seconds to release the steam in receiver 5 for outside process use immediately after the receiver 5 is drained. This operation reduces both the pressure in the receiver 5 and the horsepower requirements of pump 1 for the next cycle of the system. Valves 19 or 20 can be omitted when operation of the valve is not feasible in some cases.In the indicated steam turbine power plant, the pump 1 in Figure 5 can be connected to a deaerating tank instead of a condenser and a few condensate heaters can be installed in line 25 in series between the condenser and the deaerating tank.Pump 1 can also be used to pump condensate from a series of heaters and receiver 5 is used to remove trapped air by opening the valve 12 for approximately 2TUREAT--OMPI to 4 seconds. The rest of the operation is in accordance with the same principle as stated before.The liquid capacity of the vertical piping be¬ tween receiver 5 and pump 2 and that between valve 118 and pump 3 shall be large enough to prevent the vapor in the pipe from getting into the suction side of the pumps. The size of said vertical pipes can be enlarged. A liquid container can be installed at said vertical pipes instead of enlarging the pipe size. Timers can be used to control the operation of any automatic valve or any pump. Two timers can be used in parallel for any critical operation point. Whenever it is applicable, a float switch in any receiver or a flow switch downstream of any receiver can be used in parallel with related timers to stop the related pump operation. The control means for the various valves and pumps are schematically represented by similar respective reference characters with subscript a, i.e., la, 3a, 12a, 18a, etc. The piping arrangement employed shall provide space for any piping or equipment thermal expansion.In some cases where the condensate is available at adequate temperature and pressure, it can be released into one receiver through its distributor and controlled by a valve and timer. This saves the energy of pumping. All the automatic valves in the system shall be opened at an adequate speed to prevent a harmful impact of the vapor or liquid. The piping arrangement shall minimize such impacts by using piping of adequate size and adequate length. The size of a distributor 40, 44, 46 and 48 shall be large enough and the end of a distri¬ butor shall be strong enough to take any possible impact.In some cases, when the heating vapor is re¬ leased into the condensate in a vessel 5 or 6, a portion of the vapor reaches the top of the receiver and gradually builds up a vapor pressure. This pressure may slow down the process of releasing heating fluid. Open top sprinklers 54 as shown in Figures 2 to 4 can be used to reduce this vapor pressure. The said sprinklers are filled with comparatively cooler condensate through the conden¬ sate distribution of distributors 44, 46. Said sprinklers operate by gravity to sprinkle the condensate slowly through the small openings 55 at the bottom of the sprink¬ lers (see Figure 4) . The sprinklers are in operation until the end of the heating vapor releasing into the related receiver 5 or 6. The comparatively cooler sprinkled con¬ densate cools the indicated vapor that reaches the top of the receiver (5 or 6) , and causes a portion of such vapor to be condensed; thus the pressure of such vapor is re- duced. Whenever it is feasible, a motor forced sprinkler system can be used to replace the open top gravity sprinkler illustrated. In such case, a motor operated pump is used to pump comparatively cooler condensate from any adequate source into such sprinklers. Except for air releasing piping, all equipment and piping that contains the condensate in the system shall be insulated to preserve energy.In an exemplary case of an industrial plant con¬ densate feeding system arranged in accordance with system B (Figure 5), a 1,000 psig. steam boiler supplies all process steam to the plant. Almost all steam condensate • is returned to the boiler room, and 40 per cent of such condensate is at approximately 190 degrees F. when it reaches a condensate deaerating tank in the boiler room; such tank is connected with the suction side of pump 1 and equipped with a suitable air releasing valve and piping. Two types of equipment in said plant discharge steam mixed with condensate and the discharge fluid tem¬ perature shall be 350 degrees F. and 450 degrees F.BGREA£TOMPI When the system shown in Figure 5 starts to operate, the pump 1 pumps the condensate from the deaer¬ ating tank into the receiver 5 to the primary liquid level. Valve 13* is open to release the said fluid of 350 degrees F. temperature into such receiver 5 through dis¬ tributor 48, and to heat the condensate up to approxi¬ mately 320 degrees F. ; valve 13 is then closed. Valve 14 is opened to release not more than 1,000 psig. steam in the receiver 6 (the steam remained in the receiver from previous cycle) into the receiver 5 through the distribu¬ tor 48, and the vapor pressure in the two receivers shall then be balanced. Pump 2 shall then pump the condensate in receiver 5 into the receiver 6, and both valve 14 and pump 2 shall then be shut off. Valve 16 is opened to release the fluid of 450 degrees F. through the distribu¬ tor 40 of vessel 6 to heat the condensate in receiver 6 up to approximately 410 degrees F., and the valve 14, 16 shall then be shut off. The valves 19, 119, 12 and 112 remain closed, and the valve 20 is employed to release steam into the deaerating tank and to heat the condensate therein. The air releasing valve of such tank shall re¬ lease air from the tank with adequate timing, by utilizing a timer to meet each particular requirement. The rest of the operation shall be the same as stated previously. In a system there may be more than two receivers in series instead of the two receivers shown in Figures 1 and 5.Generally speaking, to transport the condensate by pumping is faster than by gravity drain. The receiver should be larger when the process timing is prolonged. This invention is susceptible of many embodi¬ ments utilizing the principles herein described. To avoid prolixity, detailed description of many of the numerous possible embodiments has been omitted. However, Figures 6 and 7 are provided to show two additional embodiments. Figure 6 illustrates a system in which another receiver 4 and a pump are added to the system shown in Figure 1. The receiver 4 is located upstream of the receiver 5 and the process between receiver 4 and receiver 5 is the same as it is between receivers 5 and 6 shown in Figure 5.Said receivers 4 and 5 are constructed in the way as shown' in Figure 3, but each receiver is built to meet its particular operating condition.Figure 7 shows an arrangement that keeps pumps 2 and 3 in continuous operation. This involves the vapor generator 202 receiving the condensate continuously. In accordance with this arrangement, at least three receivers 6A 6B and 6C are required, and such receivers are then oper¬ ated in a rotational way to keep the pumps in operation continuously. Each of the receivers 6 operates in the same way as previously stated, and the indicaffed rotation¬ al sequence involves means that before the valve of one receiver 6 is closed, the identical valve of the other receiver 6, which is next in rotational order, shall be fully opened. Timers should be employed to control this operational feature involved. It is advisable to have a standby receiver 6 with all the fittings required avail- able. The control system can be arranged so that the standby receiver 6 is available for use to replace any of the receivers 6 being utilized.A system which is similar to the one shown in Figure 7 is to replace each of the receivers 6 with a two receiver system as shown in Figures 1 and 5.The term pump 3 pumps condensate into the vapor generator includes all the ways that can be used to pump condensate into said generator 202 'directly or indirectly. The indirect way means that the pump pumps the condensate into a pressure vessel and from that vessel the conden¬ sate is drained or pumped into the generator as shown in Figure 5A. If the said vessel is used and the vessel has enough capacity of storage, the generator can receive a continuous condensate supply without using the suggested rotational methods described. Quite a number of minor changes may be employed as desirable or necessary r to meet a particular need but the basic principles of the methods herein disclosed are the same. The term high pressure vapor used in this disclosure includes all types of vapor which have at least 50 psig, operating pressure. The generator can be a heat exchanger, a boiler or a nuclear reactor.The piping and the valves used in accordance with the invention shall be such as to withstand the pres¬ sures and temperatures of the operational conditions en¬ countered. Stainless steel can be used in a delicate rust free operation. Steel pipe ϊfianufacturers provide all particular details for any particular requirement, The term generator , a pump , a tank , and a receiver as used herein indicates at least one of such equipment, but these terms are not limited to mean just one equipment component thereof.When a distributor is used to distribute rela- tively cool condensate into a receiver, said condensate can cool the relatively hotter vapor therein, and thus the vapor is cooled and the vapor pressure is immediately reduced. This operation is used to reduce the conden¬ sate pumping energy by reducing the pump pressure head requirements.The foregoing description and the drawings are given merely to explain and illustrate the invention and the invention is not to be limited thereto, except inso¬ far as the appended claims are so limited, since thoseIJU O y^ W skilled in the art who have the disclosure before them will be able to make modifications and variations there¬ in without departing from the scope of the invention.-BUREAT OΛ.PI | -What I claim Is :1. A high efficiency energy saving condensate feeding system for feeding condensate into a high pressure vapor generator of more than 100 psig vapor pressure, com¬ prising first and a second energy saving high pressure vess filled with the same kind of vapor as is generated by said generator and said vapor in said first vessel being high pressure vapor of which the energy content is to be restore to the system, a high pressure vapor source, means for charging condensate into said second vessel to fill said second vessel up to a substantial liquid level in said seco vessel, means for selectively isolating said second vessel, a vapor distributor with multiple openings under the liquid level in said second vessel, .means for releasing high press vapor in said first vessel into said second vessel and to inject said vapor into the condensate in said second vessel through said vapor distributor for reducing the vapor press by condensing said vapor and to preserve the energy content of said vapor, means for charging said condensate from said second vessel into said first vessel, means for isolating said first vessel from said second vessel, means for bleedi high pressure vapor from said high pressure vapor source in said first vessel to build up a pressure head in said first vessel for assisting condensate feeding into said.generator, means for charging said condensate from said first vessel i said generator until said first vessel is selectively draine while said vapor bleeding means is selectively in operation; and means for selectively isolating said first vessel from said high pressure vapor source.2. A system according to claim 1, comprising a condensate distributor with multiple openings disposed in said second vessel; and means for charging relatively coole condensate through said condensate charging line into said'BURO secono vessel and to inject said, condensate through said multiple openings of said condensate distributor into the vapor in said second vessel to condense said vapor for re¬ ducing the vapor pressure. 3. A system according to claim 1, comprising a condensate distributor with multiple openings disposed in said first vessel, and means for charging relatively cooler condensate from said second vessel into said first vessel and to inject said condensate into said vapor in said first vessel through said multiple openings of said condensate distributor to condense said vapor fcr reducing the vapor pressure.4. A system according to claim 3, comprising a condensate distributor with multiple openings disposed in said second vessel, and means for charging relatively cooler condensate through said condensate charging line into said second vessel and to inject said condensate into said vapor in said second vessel through said multiple openings of said condensate distributor to condense said vapor for reducing the vapor pressure.5. A system according to claim 1, including at least one valved releasing line leading from a source of used process vapor to at least one of said pressure vessels, a vapor distributor with multiple openings under the liquid level in said one vessel, valve means in said used vapor releasing line for releasing said used process vapor into said one pressure vessel and to inject said vapor into the condensate therein through said vapor distributor for pre¬ serving the latent heat of said used process vapor by con- densing said vapor in said condensate, after said one vessel is charged with condensate.6. A system according to claim 5, including, sprinkler means in the top portion of said one vessel for sprinkling relatively cooler condensate to cool the vapor above the condensate liαuid level in said one vessel for reducing the vapor pressure in said one vessel while said used process vapor is injected into said condensate. 7. A system according to claim 5, including a condensate distributor in said one vessel, and at least one open top gravity operated sprinkler in the top portion of said one vessel for receiving relatively cooler condensate distributed by said condensate distributor, said sprinkler being adapted for sprinkling relatively cooler condensate to reduce the vapor pressure above the liquid level in said one vessel, while said vessel is subjected to said used vapor releasing. 8. A system according to claim 7, wherein said condensate distributor has multiple openings for shower distribution of the condensate therefrom to cool the top portion of said vessel.9. A system according to claim 1, including a thir pressure vessel, a condensate communication line leading from said third vessel to said second vessel, a vapor pressure balancing line leading from second vessel to said third vessel, means for charging condensate into said third vessel up to a predetermined primary liquid level, a vapor distributor in said third vessel, fourth valve means in said balancing line for releasing vapor from said second vessel into said third vessel through said vapor distributor for injecting said vapor into the condensate in said third vessel to condense said vapor, a condensate distributor with -multiple openings in said second vessel, fifth valve means for feeding condensate from said third vessel into the second vessel through said communication line and said condensate distributor, and fourth and fifth valve means being operable for isolating said second vessel from said third vessel. 10. A system according to claim 1, wherein said high pressure vapor bleeding means bleeds said vapor from said vapor generator. 11. A condensate receiver functioning as an energy saving high pressure vessel capable of withstanding over 100 psig internal operating pressure, said vessel comprising a pressure resisting shell defining a pressure chamber, at least one elongate substantially straight tube high pressure vapor distributor disposed in said chamber and attached to an opening in said shell, and said distributor having multiple openings below.a liquid level in said chamber for injecting and substantially distributing high pressure vapor into the condensate in said chamber and said liquid level being the liquid level at the time that the • vapor distributor starts operation, at least one elongate substantially straight tube condensate distributor disposed in said chamber and attached to an opening in said shell, and having multiple openings for injecting a spray shower of condensate into the vapor in said chamber and some of said openings being directed toward the top portion of said shell for impinging the condensate onto the top portion of said shell for cooling said top portion of said shell to prevent heating said vapor by said top portion of said shell, and for reducing the vapor pressure by condensing said vapor.12. A pressure vessel according to claim 11, including at least one fluid distributor having multiple openings under liquid level in said chamber for releasing and injecting condensate from an external source into relatively cooler condensate in said chamber for energy con¬ servation.13. A pressure vessel according to claim 11, wherein said vapor distributor and said condensate distributor are connected to respective supply lines having slow opening . automatic valves therein; and an adjustable preset timer connected to each of said valves for operating each of said valves. 14. A pressure vessel according to claim 11, wherein said vapor distributor comprises more than one tubular member extending substantially horizontally with¬ in said chamber. 15. A pressure vessel according to claim 11, including at least one open top gravity operated conden¬ sate sprinkler means in the upper portion of said chamber for reducing vapor pressure above said liquid level in said chamber; and the location of the top opening of said sprinkler being located for receiving an adequate volume of sprayed condensate from said condensate distributor.16. A pressure vessel according to claim 11, including condensate sprinkler means in the top of said chamber for reducing vapor pressure above said liquid level in said chamber while said high pressure vapor dis¬ tributor is in operation,17, A high efficiency energy saving method for feeding condensate into a high pressure vapor generator of more than 100 psig vapor pressure, comprising providing first and second energy saving high pressure vessels and filling said generator, and the vapor in said first vessel being high pressure vapor of which the energy content is to be restored to the system, charging condensate into said second vessel and filling the second vessel up to a substantial liquid level in said second vessel, selectively isolating said second vessel, releasing said gigh pressure vapor in said first vessel into said second vessel and in¬ jecting said high pressure vapor into the condensate in said second vessel through a vapor distributor with ulti- pie openings under the liquid level in said second vessel and thereby reducing the vapor pressure and condensing said vapor and preserving the energy content of said vapor charging said condensate from said second vessel into said first vessel, isolating said first vessel selectively from said second vessel, bleeding high pressure vapor from a-BUO .-A. W high pressure vapor source into said first vessel and building up a pressure head in said first vessel and thereby assisting condensate feeding into said generator, charging said condensate from said first vessel into said generator until said first vessel is selectively drained while said vapor bleeding is selectively in operation;and selectively isolating said first vessel from said high pressure vapor source.18. A method according to claim 17, which comprises charging relatively cooler condensate into said second vessel through a condensate distributor with multiple openings disposed in said second vessel; and injecting said condensate through said openings into said vapor in said second vessel and thereby reducing the vapor pressure and condensing said vapor.19. A method according to claim 17, which comprises charging said condensate from said second vessel into said f-irst vessel through a condensate distributor with multiple .openings disposed in said first vessel; and injecting said condensate through said openings into said vapor in said first vessel and thereby reducing the vapor pressure and condensing said vapor.20. A method according to claim 19, which comprises charging relatively cooler condensate into said second vessel through a condensate distributor with multiple openings disposed in said second vessel, and injecting said condensate through said openings into said vapor in said second vessel and thereby reducing the vapor pressure and condensing said vapor. 21. The method according to claim 17, comprising partially releasing vapor from said first vessel for process work outside of said first vessel immediately after said first vessel is drained and isolated. 22. A method according to claim 17,comprising partially releasing vapor from said second vessel for outsi process work immediately after said first vessel is drained and isolated. 5 23. A method according to claim 17, comprising releasing used process vapor into the condensate of at least one of said vessels through a vapor distributor there with multiple openings; and thereby condensing said vapor in said condensate for preserving the latent heat of said lø used vapor.24. A method according to claim 17, comprising releasing condensate of relatively high temperature into the condensate in one of said vessels through a fluid distributor therein; and thereby heating the condensate in15 said one vessel.25. A method according to claim 23, comprising sprinkling relatively cooler condensate from at least one condensate sprinkler in the top of one of said vessels, and thereby cooling vapor in said one vessel and reducing the20 vapor pressure in said one vessel.26. A method according to claim 25, which com¬ prises releasing said used vapor into said one vessel thro at least one vapor distributor therein from different vapo sources of different temperatures and such releasing being25 in multiple stages.27. A method according to claim 17, comprising charging said condensate from said first vessel into an additional pressure vessel, and then charging condensate fr said additional pressure vessel into said vapor generator.30 28. A method according to claim 27 , comprising charging condensate into said generator at a predetermined speed as a non-stop continuous operation .- 29. A method according to claim 17, comprising effecting all the operations, except charging condensate into said second vessel and pumping, by opening an auto¬ matic valve for fluid releasing and closing one or two auto- matic valves for said isolating, controlling each valve with a respective adjustable preset timer connected thereto, and controlling each valve by means of a respective adjustable preset timer connected thereto.30. A method according to claim 23, comprising operating at least three- sets of said vessels in an order of rotation,and thereby maintaining continuous releasing of said used vapor into said vessels.31. A method according to claim 17, comprising operating at least three sets of said vessels in an order of rotation, and thereby maintaining continuous condensate feeding to said generator from said vessels.32. A method according to claim 17, which com¬ prises bleeding vapor from said high pressure vapor source into the condensate in said first vessel through a vapor distributor therein with multiple openings and thereby heating said condensate and imposing a pressure head in said first vessel.33. A method according to claim 20, which com¬ prises sprinkling condensate from at least one open top sprinkler in the top of said one vessel for reducing the vapor pressure above the liquid level in said one vessel.34. A method according to claim 17, including providing a third pressure vessel in series with said second vessel, charging condensate into said third vessel p fill same up to a predetermined primary liquid level, releasing and injecting vapor from said second vessel into said con¬ densate in said third vessel through a vapor distributor with multiple openings to condense said vapor in said condensate for reducing the vapor pressure in said third vessel; and charging said condensate from said third vessel into said second vessel.35. A method according to claim 17, which com¬ prises bleeding superheated vapor into said first vessel from said high pressure vapor source to build up said vapor head. AMENDED CLAIMS (received by the International Bureau on 13 March 1979 (13.03.79))1. A high efficiency energy saving condensate feeding system for feeding condensate into a high pressure vapor generator of more than 100 psig vapor pressure, com¬ prising a first and a second energy saving high pressure vessel filled with the same kind of vapor as is generated by said generator and said vapor in said first vessel being high pressure vapor of which most of the energy content is to be restored to the system, means for charging condensate into said second vessel to fill said second vessel up to a substantial liquid level in said second vessel, means for selectively isolating said second vessel, a vapor distributor with multiple openings under the liquid level in said second vessel, means for releasing high pressure vapor in said first vessel into said second vessel and to inject said vapor into the condensate in said second vessel through said vapor distributor for reducing the vapor pressure by condensing most of said vapor and to preserve the - energy content of said condensed vapor, means for charging said condensate from said second vessel into said first vessel, means for isolating said first vessel from said second vessel, means for bleeding high pressure vapor from said high pressure vapor generator into said first vessel to build up a pressure head in said first vessel for assisting condensate feeding into said generator, means for charging said condensate from said first vessel into said generator until said first vessel is selectively drained while said vapor bleeding means is selectively in operation; and means for selectively isolating said first vessel from said high pressure vapor source. 2. A system according to claim 1, comprising a condensate distributor with multiple openings disposed in said second vessel; and means for charging relatively cooler condensate into said second vessel and to inject said condensate through said multiple openings of said condensate distributor into the vapor in said second vessel to condense said vapor for reducing the vapor pressure. 3. A system according to claim 1, comprising a condensate distributor with multiple openings disposed in said first vessel, and means for charging relatively cooler condensate from said second vessel into said first vessel and to inject said condensate into said vapor in said first vessel through said multiple openings of said condensate distributor to condense said vapor for reducing the vapor pressure.4. A system according to claim 3, comprising a condensate distributor with multiple openings disposed in said second vessel, and means for charging relatively cooler condensate into said second vessel and to inject said condensate into said vapor in said second vessel through said multiple openings of said condensate dis¬ tributor to condense said vapor for reducing the vapor pressure.5. A system according to claim 1, including at least one valved releasing line leading from a source of used process vapor to at least one of said pressure vessels, a vapor distributor with multiple openings under the liquid level in said one vessel, valve means in said used vapor releasing line for releasing said used process vapor into said one pressure vessel and to inject said vapor into the condensate therein through said vapor distributor for preserving most of the latent heat of said used process vapor by condensing most of said vapor in said condensate, after said one vessel is charged with condensate. 6. A system according to claim 5, including, sprinkler means in the top portion of said one vessel for sprinkling relatively cooler condensate to cool the vapor above the condensate liquid level in said one vessel for reducing the vapor pressure in said one vessel while said used process vapor is injected into said condensate.7. A system according to claim 5, including a condensate distributor in said one vessel, and at least one open top gravity operated sprinkler in the top portion of said one vessel for receiving relatively cooler condensate distributed by said condensate dis¬ tributor, said sprinkler being adapted for sprinkling relatively cooler condensate to reduce the vapor pressure above the liquid level in said one vessel, while said vessel is subjected to said used vapor releasing.8. A system according to claim 7, wherein said condensate distributor has multiple openings for shower distribution of the condensate therefrom to cool the top portion of said vessel.9. A system according to claim 1, including a third pressure vessel, a condensate communication line leading from said third vessel to said second vessel, a vapor pressure balancing line leading from second vessel to said third vessel, means for charging condensate into said third vessel up to a substantial liquid level, a vapor distributor in said third vessel, means in said balancing line for releasing vapor from said second vessel into said third vessel through said vapor dis- tributor for injecting said vapor into the condensate in said third vessel to condense most of said vapor, a condensate distributor with multiple openings in said second vessel, means for feeding condensate from said third vessel into the second vessel- through said communication line. 10. A high efficiency energy saving condensate feeding system for feeding condensate into a high pressure vapor generator of more than 100 psig vapor pressure, com¬ prising a first and a second energy saving high pressure vessels filled with the same kind of vapor as is generated by said generator and said vapor in said first vessel being high pressure vapor> a high pressure vapor source, means for charging condensate into said second vessel to fill said second vessel up to a substantial liquid level in said second vessel, a vapor distributor with multiple openings under the liquid level in said second vessel, means for releasing high pressure vapor in said first vessel into said second vessel and to inject said vapor into the condensate in said second vessel through said vapor distributor for reducing the vapor pressure by condensing most of said vapor and to preserve the energy content of said condensed vapor, means for charging said condensate from said second vessel into said first vessel, means for isolating said first vessel from said second vessel, means for bleeding high pressure vapor from said high pressure vapor source into said first vessel to build up a pressure head in said first vessel for assisting condensate feeding into said generator, means for charging said condensate from said first vessel into said generator until said first vessel is select¬ ively drained while said vapor bleeding means is select¬ ively in operation; and means for selectively isolating said first vessel from said high pressure vapor source.11. A condensate receiver functioning as an energy saving high pressure vessel capable of with¬ standing over 100 psig internal operating pressure, said vessel comprising a pressure resisting shell defining a pressure chamber, at least one elongate substantially straight tube high pressure vapor distributor disposed in said chamber and attached to an opening in said shell, and said distributor having multiple openings below a liquid level in said chamber for injecting and substantially distributing high pressure vapor into the condensate in said chamber and said liquid level being the liquid level at the time that the vapor distributor starts operation, at least one elongate substantially straight tube con¬ densate distributor disposed in said chamber and attached to an opening in said shell, and having multiple openings for injecting a spray shower of condensate into the high pressure vapor in said chamber and some of said openings being directed toward the top portion of said shell for impinging the condensate onto the top portion of said shell for cooling said top portion of said shell to prevent heating high pressure vapor in said shell by said top portion of said shell, and for reducing the vapor pressure by condensing some of said vapor.12. A*pressure vessel according to claim 11, including at least one fluid distributor having multiple openings under liquid level in said chamber for releasing and injecting condensate from an external source into relatively cooler condensate in said chamber for energy conservation. 13. A pressure vessel according to claim 11, ' wherein said vapor distributor and said condensate distributor are connected to respective supply lines having slow opening automatic valves therein; and an adjustable preset timer connected to each of said valves for operating each of said valves.14. A pressure vessel according to claim 11, wherein said vapor distributor comprises more than one high pressure tubular member extending substantially horizontally within said chamber. 15. A pressure vessel according to claim 11, including condensate sprinkler means in the top of said chamber for reducing vapor pressure above said liquid level in said chamber while said high pressure vapor distributor is in operation.16. A condensate receiver functioning as an energy saving pressure vessel, said vessel comprising a pressure resisting shell defining a pressure chamber, at least one vapor distributor disposed in said chamber and attached to an opening in said shell, and said dis¬ tributor having multiple openings below a substantial liquid level in said chamber for injecting relatively higher pressure vapor into the condensate in said chamber and said liquid level being the liquid level at the time that the vapor distributor starts to operate, at least one high pressure condensate distributor with multiple openings disposed in said chamber and attached to an opening in said shell for injecting' a spray shower of relatively cooler condensate into high pressure vapor in said chamber to reduce the vapor pressure, and at least one open top gravity operated condensate sprinkler means in the upper portion of said chamber and the location of the top opening of said sprinkler being located for receiving a volume of sprayed condensate from said con- densate distributor.17. A high efficiency energy saving method for feeding condensate into a high pressure vapor generator of more than 100 psig vapor pressure, comprising provid¬ ing first and second energy saving high pressure vessels and filling said vessels with the same kind of vapor as is generated by said generator, and the vapor in said first vessel being high pressure vapor, charging conden¬ sate into said second vessel and filling the second-BU0A, WI vessel up to a substantial liquid level in said second vessel, selectively isolating said second vessel, re¬ leasing said high pressure vapor in said first vessel into said second vessel and injecting said high pressure vapor into the condensate in said second vessel through a vapor distributor with multiple openings under the liquid level in said second vessel and thereby reducing the vapor pressure and condensing most of said vapor and preserving the energy content of the condensed vapor, selectively charging said condensate from said second vessel into said first 'vessel, isolating said first vessel selectively from said second vessel, bleeding high pressure vapor from a high pressure vapor source into said first vessel and building up a pressure head in said first vessel and thereby assisting condensate feeding into said generator, charging said condensate from said first vessel into said generator until said first vessel is selectively drained while said vapor bleeding is selectively in operation; and selectively isolating said first vessel from said high pressure vapor source.18. A method according to claim 17, which comprises charging relatively cooler condensate into said second vessel through a condensate distributor with multiple openings disposed in said second vessel; and injecting said condensate through said openings into said vapor in said second vessel and thereby reducing the vapor pressure and condensing some of said vapor.19. A method according to claim 17, which comprises charging said condensate from said second vessel into said first vessel through a condensate distributor with multiple openings disposed in said first vessel; and injecting said condensate through said openings into said vapor in said first vessel and thereby reducing the vapor -36- pressure and condensing most of said vapor.20. A method according to claim 19, which comprises charging relatively cooler condensate into said second vessel through a condensate distributor with multiple openings disposed in said second vessel, and injecting said condensate through said- openings into said vapor in said second vessel and thereby reducing the vapor pressure and condensing some of said vapor.21. The method according to claim 17, compris- ing partially releasing vapor from said first vessel for process work outside of said first vessel immediately after said first vessel is drained and isolated.22. A method according to claim 17, comprising partially releasing vapor from said second vessel for outside process work immediately after said- first vessel is drained and isolated.23. A method according to claim 17, comprising releasing used process vapor into the condensate of at least one of said vessels through a vapor distributor therein with multiple openings; and thereby condensing most of said vapor in said condensate for preserving the latent heat of said condensed used vapor.24. 'method according to claim 17, comprising releasing condensate of relatively high temperature into the condensate in one of said vessels through a fluid distributor with multiple openings therein; and thereby heating the condensate in said one vessel.25. A method according to claim 23, comprising sprinkling relatively cooler condensate from at least one condensate sprinkler in the top of one of said vessels, and thereby cooling vapor in said one vessel and reducing the.vapor pressure in said one vessel, during said used vapor releasing.0M 26. A method according to claim 23, which com¬ prises releasing said used vapor into said one vessel through at least one vapor distributor therein from different vapor sources of different temperatures and such releasing being in multiple stages.27. A method according to claim 17, comprising charging said condensate from said first vessel into an additional pressure vessel, and then charging condensate from said additional pressure vessel into said vapor generator.28. A method according to claim 27, comprising charging condensate into said generator from said pressure vessel at a predetermined speed as a non-stop continuous operation. 29. A method according to claim 17, comprising effecting all the operations, except charging condensate into said second vessel and pumping, by opening an auto¬ matic valve for fluid releasing and closing' one or two automatic valves for said isolating, controlling each valve by means of a respective adjustable preset timer connected thereto.30. A method according to claim 23, comprising operating at least two sets of said vessels in an order of rotation, and thereby maintaining continuous releasing of said used vapor into said vessels.31 A method according to claim 17, comprising operating at least two sets of said vessels in an order of rotation, and thereby maintaining continuous condensate feeding to said generator from said vessels. 32. A method according to claim 17, which com¬ prises bleeding vapor from said high pressure vapor source into the condensate in said first vessel through a vapor distributor therein with.multiple openings and thereby heating said condensate and imposing a pressure head in said first vessel.33. A method according to claim 25, which com¬ prises sprinkling condensate from at least one open top sprinkler in the top of said one vessel for reducing the vapor pressure above the liquid level in said one vessel.34. A method according to claim 17, including providing a third pressure vessel in series with said second vessel, charging condensate into said third vessel to fill same up to a substantial liquid level in said third vessel, releasing and injecting vapor from said second vessel into said condensate in said third vessel through a vapor distributor with multiple openings to condense most of said vapor in said condensate; and charging said condensate from said third vessel into said second vessel.35. A method according to claim 17, which com¬ prises bleeding superheated vapor into said first vessel from said high pressure vapor source to build up. said vapor head.O kA>_. WIP | CHEN T | CHEN T |
WO-1979000204-A1 | 1,979,000,204 | WO | A1 | EN | 19,790,419 | 1,979 | 20,090,507 | new | F16K27 | null | F16K27 | F16K 27/08 | PROTECTIVE HOOD FOR VALVES WITH HAND WHEELS | A protective hood, mainly cylindrical, having an end wall (8) at one end and being open at the other end, intended for fitting over valves for conduits, said valves being of the type fitted with a hand wheel. The hood (1) is made of a fabric (7), such as glass fibre fabric, able to keep out solid contaminating particles but permeable to gas and, further, heat resistant, tensioned over a frame of metal wire (10) wound to coil spring shape, so that for transport and storage the hood can be kept axially compressed to a height several times smaller than when it is expanded by the spring action of the frame. At its upper, closed end the hood is fitted with fastening means, such as clamps (13) or the like, intended to be passed over the spokes (4) of the hand wheel for retaining the hood over the valve. | Protective hood for valves with hand wheelsIn process industries, e.g. the cellulose industry, extensive conduit systems are used which are fitted with shut-off and control valves, such as, for example, wedge valves and similar types of valve, usually fitted with a hand wheel and manually operated. The valves are often located in an environment where, after some time, they become heavily coated with contaminants on their outside. The valves and their hand wheels are often more or less totally caked with or buried in contaminating particles which, apart from making the operation of the valves more difficult to the operators, can also cause corrosion and damage to valve spindles and bearings.It is therefore known to fit the valves with protective hoods, which are usually made of sheet metal and more or less specially made from one application to another with regard to sizes and means for attaching them to the valves. These hoods are expensive and show other disadvantages as well. They become heavily dirtied on their outside and are also time-consuming and clumsy to fit and remove, which makes them unattractive to handle, so that the operators of the valves tend to neglect re-fitting the hoods after once having removed them. Further, it is costly, space-consuming and impractical to stock and keep in re- serve the necessary number of all the various hood sizes, since it is a question of large numbers - there may be thousands of valves in one single plant.The object of the present invention is to provide a protective hood which is light, inexpensive, simple to fit and remove, has a re- pelling effect on contaminating solid particles falling down on it and requires little space for transport and storing. This has been obtained by giving the protective hood the characteristics set forth in the accompanying Claims.The invention is described in closer detail with reference to the enclosed drawing. Fig. 1 in the drawing shows a side elevation of a protective hood fitted over a wedge valve shown partly in side elevation and partly by outlines. Fig. 2 is a perspective sketch of the hood in the expanded position and fig. 3 a perspective sketch of same when compressed for transport or storage. In the drawing the numeral 1 designates a hood in accordance with the invention, 2 is a valve fitted with a hand wheel 3 with spokes 4, a nut 5 for retaining the hand wheel, and a valve spindle 6. The hood 1 is made from a fabric 7, which is suitably heat resistant and can, for example, be a glass fibre fabric. The fabric should be dense enou to give efficient protection against penetration of contaminating sol particles but should be permeable to rising air streams produced in¬ side the hood in cases where hot media are transported in the conduit on which the valve is fitted. The hood is made in the form of a cylinder, open at one end and fitted, at the other end, with an end wall 8 with a central opening 9 The fabric of the hood is tensioned over a frame consisting of metal wire 10 wound to helical spring shape, to which the fabric is fastene at suitable points, e.g. by sewing the fabric around the wire, the spring action keeping the hood expanded in the axial direction. At th end of the hood where the end wall 8 is provided, the hood is fitted with four rods 11, arranged like the spokes of a wheel and inter¬ connected by a ring 12 defining the central opening of the end wall, to which ring the fabric of the end wall is fastened. The rods 11 are fitted with two fork-shaped clamps 13 intended to be passed over the spokes 4 of the hand wheel.The hoods in accordance with the invention are suitably made in a number of different sizes corresponding to different standard sizes of valves and their hand wheels. Since the frame is made in the form of a helical spring, the hoods can, for transport and storage, be compressed in the way shown in fig. 3 and can then suitably be kept in this position either direct by their packaging or, for example, by a pair of clamps 14 or similar. In this way the hoods require a mini¬ mum of transport and storage space, which is of great importance within process industries where large numbers of hoods may be needed. When a hood is to be fitted over a valve, the helical spring of the frame is released, so that the hood is expanded to its full length, whereupon the hood is fastened by passing the clamps 13 over the spokes 4 of the hand wheel of the valve. It is suitable to have the size of the hood in the axial direction so adjusted that the bottom edge of the hood will seal - under light spring pressure - against the projecting flange 15 of the valve housing or a corre¬ sponding surface. A valve spindle 6 can be passed through the central opening 9 of the hood. The ring 12 defining the central opening seals against the hand wheel nut 5 or a corresponding part, depending on the type of valve.^JREALTOMPI_«&/__ IPO Since the fabric of the hood is permeable to gas, the outside of the hood will to a considerable extent be self-cleaning in the many cases where hot media are transported in the conduits and the heat80 from these media causes rising currents of air inside the hood. The permeable hood will also function as a protection against bodily in¬ juries caused by jets of steam or other hot media escaping from the valve, since the hood will act as a brake and spreader and, at the same time, is less inclined to be thrown off the valve due to the pressure85 than is a completely impermeable hood.liϋREATrOMPI. _ | Claims1. A protective hood for fitting over valves for conduits, said valves being of the type fitted with a hand wheel and said hood being substantially cylindrical, open at one end and provided with an end wall at its other end, c h a r a c t e r i z e d i n t h a t the hood (1) is made of a fabric (7), such as glass fibre fabric, able to keep out solid contaminating particles but permeable to gas and, further, heat resistant, tensioned over a frame of metal wire (10) wound to coil spring shape, so that for transport and storage said hood can be kept axially compressed to a height several times smaller than when the hood is kept expanded by the frame due to its spring action; and in that, at the upper, closed end of the hood, the frame is fitted, on its inside, with two or more clamps (13) or similar, intended to be passed over the spokes (4) of the hand wheel for re¬ taining the hood over the valve. 2. A protective hood as claimed in claim 1, c h a r a c t e r¬ i z e d i n t h a t the height of said hood (1), i.e. its axial extension, is so adjusted that the lower, open end of the hood will seal, under light spring pressure, against a flange (15) of the valve housing or a corresponding surface. BOREAiOMPI | PERSSON A | PERSSON A |
WO-1979000205-A1 | 1,979,000,205 | WO | A1 | XX | 19,790,419 | 1,979 | 20,090,507 | new | F16K3 | F02M69, F16K5, F16K27 | F02M69 | F02M 69/24 | A CARBURETOR FOR INTERNAL COMBUSTION ENGINES | In the operation of some types of fuel injected carburetors, it is necessary that the air valve and fuel valve be of simple construction and controlled by common linkage. In the instant carburetor the air valve (40) is operatively connected to the fuel valve (15) by common linkage (12). When the engine is idling, fuel flows only from pressurized line (18), through flats (19), into annular space (17) and into the intake manifold (23). When it is desired to increase the operational speed of the engine, the common linkage (12) is rotated causing the air valve (40) to further open and simultaneously causing the fuel valve (15) to move upwardly. This upward movement uncovers fuel orifices (16), which allows the fuel from line (18) to be injected through orifices (16) and (22) into the intake manifold (23). All the while, fuel continues to be injected via annular space (17). Likewise, when it is desired to decrease the operational speed the common linkage is oppositely rotated causing the air valve to close and causing fuel valve (15) to move downwardly blocking some orifices. | A CARBURETOR FOR INTERNAL COMBUSTION ENGINESBackground of the Invention and Prior Art StatementThis invention relates to a device for supplying fuel to an internal combustion engine. More particularly, this in¬ vention relates to an improved device for injecting fuel into the intake manifold of an internal combustion engine.The prior art discloses in a number of instances the injection of fuel into the intake manifold or similar air intake conduit of an internal combustion engine. The prior art also discloses fuel injectors of numerous different constructions. Exemplary of such prior art, from all of which the present in¬ vention is patentably distinguishable/ are the following U.S. patents.U.S. Patents 1,869,821, 1,931,541, 1,995,601, 2,089,989, 2,910,057 and 4,026,259 all disclose fuel supply devices for internal combustion engines in which the fuel is in¬ jected into an intake manifold or similar air supply conduit. Moreover, in some instances, a valve for controlling the air supply and means for controlling the flow rate through the fuel injection means are controlled by a common linkage from the throttle of the motor vehicle in which the internal combustion engine is installed. However, the fuel injection means in each instance are notably different from the device of the present invention which will hereinafter be described.OMPI U.S. Patents 3,702,175 and 3,982,694 are representa¬ tive of the great diversity of constructions of fuel injection nozzles disclosed in the prior art. However, prior art fuel injection nozzles, such as those of these two patents, are notably different from the device of the present invention as will hereafter be described.It is an object of the invention to provide a device for supplying fuel to an internal combustion engine which can serve as a replacement for a conventional carburetor without otherwise substantially altering the engine.It is a further object of the invention to provide a device for supplying fuel to an internal combustion engine whi is substantially simpler and less expensive than conventional a device for supplying fuel to an internal combustion engine which results in higher gas mileage and a lower level of pol¬ lutants in the exhaust gases than a conventional carburetor o fuel injection system.Other objects and advantages of the invention will b apparent from the following description thereof.Brief Description of the InventionAccording to the invention, there is provided a devi for supplying fuel to an internal combustion engine comprisin shell, a tube received in the shell and a rod received in the tube with a sliding fit. A plurality of orifices are provide in the tube at intervals along at least a portion of the leng of the tube. The rod is insertable in the tube to an extent sufficient to block the orifices and retractable to an extent sufficient to leave the orifices unobstructed. The number of orifices left unobstructed increases in proportion to the ext to which the rod is retracted. The rod includes means for co nection to a linkage from a motor vehicle throttle for effecting axial movement of the rod. An annular space is defined between the exterior wall of the portion of the length of the tube having orifices and the portion of the length of the interior wall of the shell facing the orifices. Means are providing defining passages for admitting liquid fuel into the annular space. The fuel is ejected from the device solely through the annular space when the rod is inserted in the tube to an extent sufficient to block the orifices. Some of the fuel also passes from the an¬ nular space through the orifices to the interior of the tube from whence the fuel is ejected from the device when the rod is retracted to an extent sufficient to leave orifices unobstructed. The volumetric flow of the fuel into and through the tube in¬ creases as the number of orifices left unobstructed is increased by increasing the retraction of the rod.The device as hereinabove defined is to be used in com¬ bination with means for admitting air to the intake manifold of an internal combustion engine, the air admitting means including means defining a passage for the air and a valve for controlling passage of the air through the air passage. There is also pro¬ vided a common linkage to the valve and the rod for simultan¬ eously opening the valve and retracting the rod and simultan¬ eously closing the valve and inserting the rod, the linkage including means for connection to a motor vehicle throttle.In practice, the device is intended to be used on the intake manifold of the engine, in the same position as a con¬ ventional carburetor, for supplying fuel and air to the intake manifold.Brief Description of the DrawingsFig. 1 is an isometric view of a device according to the invention for taking the place of a conventional carburetor;Fig. 2 is a cross section taken on section line 2-2 of Fig. 1, but with the device installed on an intake manifold shown in phantom; and Fig. 3 is a cross section taken on section line 3-3 o Fig. 1, but with the device installed on an intake manifold shown in phantom,Detailed Description of a Preferred EmbodimentThe combination apparatus shown in Figs. 1-3 is funda¬ mentally a combination of a fuel supply device 10 and air supp means 11 simultaneously controlled by a common linkage 12. Th linkage 12 is common in the sense that it is shared by the f supply device 10 and air supply means 11.The fuel supply device 10 includes a shell 13, a tube received in the shell 13 and a rod 15 received in the tube 14 with a sliding fit. A plurality of orifices 16 is provided in the tube 14 at intervals along at least a portion of the lengt of the tube 14. In particular, the orifices are in a helical array of 360° extending from level A to level B of the tube 14 The rod 15 includes means 15a for connection to a linkage from motor vehicle throttle. In particular, the connection means 1 is an upper portion of the rod 15 of enlarged diameter in whic is provided a slot 15b for receiving an end of a lever of the linkage. The lower part of the means 15a also provides a shoulder 15c for abutting against the upper end 14a of the tub14 thereby to limit downward sliding of the rod 15 into the tu 14. With reference to Fig. 2, it is seen that when the should 15c of the rod 15 is abutting against the upper end 14a of the tube 14, the lower end 15d of the rod 15 and the lower end 14b of the tube 14 meet. It is also seen in Fig. 2 that with the15 thus fully inserted in the tube 14, the rod 15 is blocking the orifices 16 in the tube 14. With reference to Fig. 3, it seen that as the rod 15 is progressively retracted from the t 14, and in particular as the lower end 15d of the rod'15 rises above level B of the tube 14, first the lowermost of the orifices 16 at level B and then, in addition, orifices at higher levels are, one by one, left unobstructed. Hence, the number of orifices 16 left unobstructed increases in proportion to the ex¬ tent to which the rod 15 is retracted.An annular space 17, which is too small to actually clearly appear in Figs. 2 and 3, is defined be¬ tween the exterior wall of the portion A to B of the length of the tube having orifices 16 and the portion of the length of the interior wall of the shell 13 facing the orifices 16. The an¬ nular space 17 is merely the result of the external diameter of the tube 14 being slightly smaller than the internal diameter of the shell 13. Also provided are means 18 and 19 defining pas¬ sages for admitting liquid fuel into the annular space 17. In particular, the means 18 is a fuel supply line, and the means 19 is a flat milled onto the surface of the tube 14. The tube 14 is externally threaded and the shell 13 is internally threaded from level C to level D. Thus, the tube 14 is screwed into the shell 13. A radial bore 20 is provided through a wall of the shell 13. The radial bore 20 is internally threaded. An end portion 18a of the fuel supply line 18 is externally threaded. Consequently, the fuel supply line 18 is screwed into the bore 20. The flat 19 extends from level E, i.e., approximately at the top of the internal diameter of the fuel supply line 18 to level D, i.e., the lower end of the threads. Thus, the flat 19 communicates between the fuel supply line 18 and the annular space 17, which extends from level D to the level of the lower end 13a of the shell 13. In practice, a plurality, for example, four or five, identical flats 19 are provided around the circumference of the tube 14 to assure that one of these flats 19 is in align¬ ment with the bore 20 regardless of the angular displacement of the tube 14 relative to the shell 13.From the foregoing, it can readily be seen that at all times that fuel is flowing through the fuel supply line 18, fuel will flow into the annular space 17 due to communication from the fuel supply line 18 to the annular space 17 by means of a flat 19. The fuel which flows through this path exits from the device 10 at the juncture of the tube 14 and the shell 13 at th lower end 13a of the shell 13 as a spray which is in a frusto- conical configuration emanating from the aforesaid juncture. This takes care of the fuel requirements of the engine when idling.As the driver depresses the throttle, through a mechan cal linkage which will hereinafter be described, axial movemen is imparted to the rod 15 which retracts the rod 15 from the t 14. Hence, a progressively increasing number of orifices 16 is left unobstructed. The orifices 16 communicate between the an¬ nular space 17 and the interior of the tube 14. Hence, some o the fuel also flows through the orifices 16 into the. interior of the tube 14. Fastened onto the lower end 14b of the tube 14 is a spray cap 21 having orifices 22. The fuel which flows to the lower 14b of the tube 14 enters the spray cap 21 and exits the cap through the orifices 22 in the form of a spray. All the while, fuel continues to be sprayed in the other mode, too. The furt the rod 15 is retracted, the greater the rate at which fuel is supplied to the engine and, consequently, the more the vehicle accelerates. The fuel is sprayed into the intake manifold 23 the engine. The rod is provided with a pair of O-rings 24 and seated in respective annular grooves in the rod 15. When the 15 is fully inserted in the tube 14, the O-ring 24 is slightly above the highest orifice 16 and the 0-ring 25 is slightly bel the lowest orifice 16. When the rod 15 is retracted to the maximum extent effected by the linkage from the throttle, the ring 25 is in about the same position as the 0-ring 24 was in when the rod 15 was fully inserted in the tube 14. The O-ring 24 and 25, hence, prevent fuel vapors from seeping upwardly ou of the fuel supply device 10. To this same end, an O-ring 26 provided in an annular recess 27 provided in the upper end 13 of the shell 13. The interior surfaces of the O-ring 26 are iOMPI<$ IPO - 7 -contact with the outer face of the tube 14 and, hence, the 0- ring 26 prevents the seepage of fuel fumes upwardly out of the device 10 through the interface of the internal threads of the shell 13 and the external threads of the tube 14.The fuel supply device 10 and air supply means 11 are mounted in a housing which constitutes part of the air supply means. The housing includes a base plate 27 having a hole 28 bored through each of its corners for mounting onto the top of an intake manifold 23 in the same manner as a conventional car¬ buretor, which the present invention replaces. The housing is further constituted of a cylindrical side wall member 29 and a disc-shaped cover 30. The cover 30 is releasably held onto the cylindrical side wall member 29 by means of four screws 31. The fuel supply line 18 passes through a bore 32 provided in the cy¬ lindrical side wall member 29. The tube 14 passes through a bore 33 provided through the center of the.cover 30. The 0-ring 26, which seals off the escape of fuel from the interface of the- internal threads of the shell 13 and the external threads of the tube 14, also prevents the escape of fuel vapors through the interface of the bore 33 and the upper portion of the tube 14. The lower portion of the shell 13 is provided with external threads 13b. The base plate 27 is provided with openings 34 communicating between the interior of the housing of the device according to the invention and the interior of the intake mani¬ fold 23. Through the remaining central area 27a of the base plate 27 is provided an internally threaded bore into which the externally threaded lower end of the shell 13 is screwed. An O- ring 35 is provided at the shoulder 13c of the shell 13 situated immediately above the threaded portion of the shell 13. The 0- ring 35 is also in contact with the base plate 27 and seals off the interface of the external threads 13b of the shell 13 and the internal threads provided in the bore through the central portion 27a of the base plate- 27. An air inlet conduit 36 com¬ municates with the interior of the housing through an opening 37 in the side wall member 29. Communicating with the air inlet conduit 44, for controlling the flow of air therethrough, is a butterfly valve assembly 38. The butterfly valve assembly com¬ prises a section of conduit 39 in which a butterfly valve 40 is mounted on a pivot pin 41 which is received in journal bearings 42, 43 on the walls of the conduit section 39. Additional air inlet conduit.44 may be provided on the upstream side of the butterfly valve assembly 38. The conduit 44 may communicate wi a conventional automotive air filter at the location of which a first enters the air intake system of the motor vehicle.The linkage 12 includes a shaft 45 which is journalled in a block 46 fastened to the cover 30 by means of screws 47. rod 48 extends from the throttle (not illustrated) to a crank assembly 49 connected to one end of the shaft 45. Fastened to the shaft 45 at an intermediate point is a lever 50. The lever 50 engages the rod 15 by being received in the slot 15b in the rod 15. To the other end of the shaft 45 is connected a lever which, in turn, is pivotally connected to a crank assembly 52 which it actuates. With reference to Fig. 1, it is seen that pushing the rod 48 toward the crank ssembly 49 by means of de¬ pressing the throttle causes the crank assembly to angularly di place in the clockwise direction, thereby angularly displacing the shaft 45 in the clockwise direction, which causes the lever 50 to lift the rod 15 and causes the lever 51 and crank assembl 52 to open the butterfly valve 40 thereby to effect the simul¬ taneous introduction of air and increased quantities of fuel into the intake manifold 23, resulting in acceleration of the engine. As usual, the throttle is provided with a spring, so .. that when one takes one's foot off the throttle, the rod 48 wil move away from the crank assembly 49, thereby causing the lever 50 to push the rod 15 down again and the lever 51 and crank as¬ sembly 52 thereby to close the butterfly valve 40 again, re¬ sulting in deceleration of the engine.While the invention has been described by reference to specific, preferred embodiment thereof, it is to be understood that modifications and variations thereof which would be obviou to one skilled in the art are intended to be encompassed within the scope of the hereto appended claims. -~WREA t | WHAT I CLAIM IS :1. A device for supplying fuel to an internal combus¬ tion engine comprising a shell, a tube received in the shell and a rod received in the tube with a sliding fit, a plurality of orifices in the tube at intervals along at least a portion of the length of the tube, the rod being insertable in the tube to an extent sufficient to block the orifices and retractable to an ex¬ tent sufficient to leave the orifices unobstructed, the number of orifices left unobstructed increasing in proportion to the extent to which the rod is retracted, the rod including means for con¬ nection to a linkage from a motor vehicle throttle for effecting axial movement of the rod, an annular space defined between the exterior wall of the portion of the length of the tube having orifices and the portion of the length of the interior wall of the shell facing said orifices, and means defining passages for admitting liquid fuel into the annular space, whereby the fuel is ejected from the device solely through the annular space when the rod is inserted in the tube to an extent sufficient to block the orifices and some of the fuel also passes•from the annular space through the orifices to the interior of the tube from whence the fuel is ejected from the device when the rod is re¬ tracted to an extent sufficient to leave orifices unobstructed, the volumetric flow rate of the fuel into and through the tube increasing as the number of orifices left unobstructed is in¬ creased by increasing the retraction of the rod.2. The combination of a device according to Claim 1 and means for admitting air to the intake manifold of an internal combustion engine, the air admitting means including means de¬ fining a passage for the air and a valve for controlling passage of the air through the air passage.BUREOMPI 3. The combination of Claim 2 and a common linkage t the valve and the rod for simultaneously opening the valve an retracting the rod and simultaneously closing the valve and i serting the rod, the linkage including means for connection t motor vehicle throttle.4. The combination of Claim 1 and an internal combu tion engine intake manifold, the device communicating with th interior of the intake manifold for the injection of fuel thr the device into the intake manifold.5. The combination of Claim 2 and an internal combu tion engine intake manifold, the fuel supplying device and th air admitting means communicating with the interior of the in take manifold for the simultaneous injection of fuel and admi sion of air into the intake manifold.6. The combination of Claim 3 and an internal combu tion engine intake manifold, the fuel supplying device and th air admitting means communicating with the interior of the in take manifold for the simultaneous injection of fuel and admi sion of air into the intake manifold. | BERNECKER G | BERNECKER G |
WO-1979000208-A1 | 1,979,000,208 | WO | A1 | XX | 19,790,419 | 1,979 | 20,090,507 | new | B21K5 | null | B21C3, B21K5, B22F7, B30B11 | B21C 3/02D, B21C 3/18 | WIRE DRAWING DIE AND METHOD OF MAKING THE SAME | In the past, wire drawing dies employing blanks having polycrystalline aggregate of synthetic diamond cores have been shrink-fitted in the casing. Such shrink-fitting of the blank has required a substantial amount of skilled labor and has resulted in excessive breakage of the synthetic diamond core. Accordingly it has been desirable to provide a wire drawing die employing a synthetic hard, wear-resistant material, and a method of making the same which eliminates shrink-fitting of the blank in the casing. In accordance with the method a wire drawing die (10) is produced by providing a metal casing (12) with a cavity (18) having an undercut (22) adjacent the bottom (20), a first layer (51) of metal powder is deposited in the cavity (18), a metal blank (38) having a core (40) formed of a synthetic hard, wear-resistant material is placed on the first layer (51) and a second, layer (54) of metal powder is deposited in the cavity covering the first layer (51) and the blank (38). A cylindrical plug (24), having a cavity (30) formed in one end, is inserted in the casing cavity (18) with a close slip-fit and pressure is applied to the other end of said plug (24) to thereby compress the metal powder layers. The casing (12) is heated to a temperature which is sufficient to melt the metal powder but is less than the thermal degradation temperature of the core (40) thus forming a body of molten metal which encapsulates the blank (38). The casing (12) is cooled to solidify the metal body and thereby secure the plug (24) and blank (38) in the casing cavity (18). | WIRE DRAWING DIE AND METHOD OF MAKING THE SAMEBACKGROUND OF THE INVENTION Field of the Invention This invention relates generally to wire drawing dies and methods of making such dies, and more particularly to a wire drawing die employing a synthetic hard, wear- resistant material and the method of making the same.Description of the Prior Art Natural diamond wire drawing dies have been manu¬ factured for many years and typically comprise a metal casing in which the diamond is mounted, the casing in turn being adapted to be mounted in a wire drawing machine. U.S. Patent No. 2,171,323 discloses one prior method of making a diamond wire drawing die. In another, more re¬ cent method of making a diamond wire drawing die, a flat- bottomed cavity is machined in the casing and a layer of powdered metal is deposited in the cavity, the diamond placed thereon, and additional powdered metal is depos- ited over the diamond. Powdered metal is then deposited in the cavity of a metal plug which is then inserted in the casing cavity. The casing is then heated, as by in¬ duction heat or gas firing and pressure is applied to the plug thereby to solidify the metal powder to encapsulate the diamond. The usual countersunk openings are then machined in the back side of the casing and in the plug and 'the die opening is drilled through the diamond. U.S. Patent No. 3,978,744 discloses another more recent method of making natural diamond wire drawing dies.OMPI Polycrystalline aggregates of synthetic diamond have recently become available and an annular sintered tungsten carbide blank having a core of polycrystalline aggregate of synthetic diamond is sold by the General Electric Com- pany under the trademark Compax . In the past, wire drawing dies employing blanks having polycrystalline aggregate of synthetic diamond cores have been shrink- fitted in the casing; however, such shrink-fitting of the blank has required a substantial amount of skilled labor and has resulted in excessive breakage of the synthetic diamond core. Furthermore, a Compax blank in the form of a segment of a circle has recently become available which, because of its configuration, does not permit such shrink- fitting in the casing. Still further, the General Electric Company has even more recently introduced another synthe¬ tic hard, wear-resistant metal suitable for use in wire drawing dies, .that material being polycrystalline cubic boron nitride sold under the trademark Borazon. It is 'therefore desirable to provide a wire drawing die employing a synthetic hard, wear-resistant material, and a method of making the same, which eliminates shrink-fitting of the blank in the casing and reduces breakage of the core.SUMMARY OF THE INVENTION In accordance with the method of the invention, in its broader aspects, a metal casing is provided, a cylin¬ drical cavity is formed in the front casing side which has a bottom spaced from the back casing side, and the side wall of the cavity is unde cutted adjacent the bottom. A first layer of metal powder is deposited in the casing covering the bottom, a metal blank having a core formed of a synthetic hard, wear-resistant material is placed on the first layer with the core concentric with the cavity, and a second layer of metal powder is deposited in the cavity covering the first layer and the blank, the metal powder of both layers having a melting point lower than the thermal degradation temperature of the core. A cylindrical plug is provided having opposite ends and with its outside diameter so related to the inside diameter of the casing cavity as to provide a close slip fit therein. A cylindrical cavity is formed in one end of the plug having a bottom spaced from the other plug end, the in¬ side diameter of the plug cavity adjacent the bottom thereof being greater than at the one plug end. The plug is inserted in the casing cavity with the plug cavity facing the second metal powder layer until the plug cavity bottom engages the second layer. Pressure is applied to the other end of the plug thereby to compress the metal powder layers, and the casing is heated for a time and at a temperature sufficient to melt the metal powder but at a temperature less than the thermal degradation te - perature of the core thus forming a body of molten metal which encapsulates the blank. The pressure and heating is terminated and the casing is cooled to solidify the metal body thereby to secure the plug and blank in the casing cavity. Countersunk openings are formed in the back side of the casing and the other end of the plug which respectively extend through the metal body to the core, and a die opening is drilled through the core communicating between the countersunk openings.It is accordingly an object of the invention to pro- vide an improved method of making a wire drawing die.Another object of the invention is to provide an im¬ proved wire drawing die.A further object of the invention is to provide an improved method of making a wire drawing die employing a synthetic, hard, wear-resistant material, such as poly¬ crystalline aggregate of synthetic diamond or a polycrys¬ talline cubic boron nitride.Yet another object of the invention is to provide an improved wire drawing die employing a synthetic, hard, wear-resistant material, such as polycrystalline aggregate of synthetic diamond or a polycrystalline cubic b'oron nitride.-BUREATTOMPI. ~fa W1P0 _ > The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view illustrating the method of the invention;- Fig. 2 is a top view taken generally along the line 2-2 of Fig. 1 but before insertion of the plug in the casing cavity; andFig. 3 is a cross-sectional view showing the finished wire drawing die of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTReferring first to Fig. 3 of the drawing, the im¬ proved wire drawing die of the invention, generally indi¬ cated at 10, comprises a cylindrical metal casing 12, preferably, but not necessarily, formed of stainless steel, having flat, parallel, front and back sides 14,16. Cylindrical cavity 18 is formed in front side 14 of casing 12 and has flat bottom 20 spaced from and paral¬ lel with back side 16. The side wall of cavity 18 is undercut adjacent bottom 20, as at 22. Cylindrical plug 24 having top and bottom ends 26, 28 is closely fitted in cavity IS with its bottom end 28 spaced from bottom 20. Plug 24 has cavity 30 formed in its bottom end 28 having flat bottom 32 parallel with bottom 20 of cavity 18. Cavity 30 in plug 24 defines annular flange 34 which is inclined inwardly away from the side wall of cavity 18 so that the inside diameter of cavity 30 is greater at its bottom 32 than at bottom end 28 of plug 24.The cavity defined between bottom 20 of casing cavity 18 and bottom 32 of plug cavity 30 is filled with body 36 of solidified metal which encapsulates blank 38■BUREOfΛPI ^fa W1P0 and secures plug 24 in cavity 18 by virtue of the in¬ wardly inclined annular flange 34 thereon. In the il¬ lustrated embodiment, blank 38 forms a segment of a circle, as shown in Fig. 2, and may be of the type sold by the General Electric Company under the trademark Compax. Blank 38 is typically formed of sintered tungsten carbide and has core 40 therein formed of polycrystalline aggre- ' gate of synthetic, i.e., man-made diamond. Alternatively, core 40 may be formed of polycrystalline cubic boron nit- ride. Blank 38 encapsulated in metal body 36 is spaced from bottom 20 of casing cavity 18 and bottom 32 of plug cavity 30 and has flat surfaces 42, 44 respectively paral¬ lel with cavity bottoms 20, 32. Core 40 has die opening 46 therethrough concentric with cavity 18. The usual countersunk openings 48, 50 are formed in back side 16 of casing 12 and end 26 of plug 24 and respectively ex¬ tend through metal body 36 to core 40 to communicate with die opening 46.In one specific embodiment of the wire drawing die shown in Fig. 3 and described above, casing 12 has a di¬ ameter of 1-1/8 inch and a thickness of .360 inch. Cavity 18 has a depth of .260 inch and an inside diameter of .312 inch. The inside diameter of cavity 30 of plug 24 at bottom 32 is .262 inch and the depth of cavity 30 is .050 inch. Bottom 32 of plug 24 is spaced from bottom 20 of cavity 18 by about .125 inch.Referring now to Figs. 1 and 2 of the drawings, in the method of making wire drawing die 10, cylindrical cavity 18 is machined in front side 14 of casing 12, as with a screw machine, and undercut 22 is machined, as with a lathe. Layer 52 of suitable metal powder, to be hereinafter described, is then deposited in cavity 18 covering bottom 20 to a level slightly above undercut 22 and slight pressure is applied on layer 51 with a plane plunger (not shown) so that top surface 52 is plane and parallel with cavity bottom 20. Blank 38 having core 40 therein is then placed on top surface 52 of layer 51 and adhered thereto by a suitable adhesive, such as sodium silicate, which will vaporize under high temperature. Blank 33 is located so that core 40 is concentric with cylindrical cavity 18.A second layer 54 of metal powder is then deposited in cavity 18 to cover blank 38 to a depth of about .060 inch. The metal powder of which both layers 51, 54 is formed has a melting point slightly less than the ther- mal degradation temperature of the core 40, i.e., slightly less than about 1200°F in the case of a core 40 formed of a polycrystalline aggregate of synthetic diamond. A metal powder composed of, by weight: 45% cu 45% ni10% Easy-Flow 45 brazing alloy, which is composed of: 45% ag 15% cu 16% zn24% cd which has a melting point of 1125° F. has been found to be suitable for the purpose.Plug 24 is machined from suitable metal, such as stainless steel, and has an initial length greater than in the finished die. The outside diameter of plug 24 is so related to the inside diameter of cavity IS as 'to pro¬ vide a close slip fit. Cavity 30 is machined in end 28 of plug 24 so as to provide the inwardly inclined annu- lar flange 34.Plug 24 is then inserted in cavity 18 and casing 12 until bottom 32 of cavity 30 engages powder metal layer 54 and pressure, which may be on the order of 800 p.s.i. gauge, is applied on end 26a of plug 24, as by ram 56, thereby to compress powder metal layers 51, 54. Casing 12 is then heated, as by being placed within induction heating coil 58, the temperature being brought up slowly to a level sufficient to melt the metal powder but not • to exceed 1200° F. In the specific embodiment described, a heating time of about one minute is sufficient to melt the powder metal layers 51, 54 to form molten metal body 36 encapsulating blank 38. Following termination of the heating, the pressure is maintained for an additional short period of time, such as about thirty seconds in the specific embodiment described, in order sufficiently to solidify metal body 36 to secure plug 24.Following further cooling of casing 12 and plug 24, end 26a of plug 24 is machined so as to be flush with front side 14 of casing 12, as shown in Fig. 3. Counter¬ sunk openings 48, 50 are then machined following which, core 40 is drilled to form die opening 46.While the invention has been described in connection with use of die blank 38 which is a segment of a circle, it will be readily understood that an annular die blank may be employed. It will further be understood that while a specific metal powder composition is described, other metal powders may be employed so long as the melting point does not exceed the thermal degradation temperature of the core 40, the pressure and temperature, and the time of application of pressure and temperature in part depending upon the specific metal powder used.While there have been described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention. | WHAT IS CLAIMED IS:1. The method of making a wire drawing die com¬ prising the steps of: providing a metal casing having front and back sides; forming a cylindrical cavity in said front casing side having a bottom spaced from said back casing side, and undercutting the side wall of said cavity adjacent said bottom; depositing a first layer of metal powder in said cavity covering said bottom; placing on said first layer a metal blank having a core formed of a synthetic hard wear-resistant material with said core concentric with said cavity; depositing a second layer of metal powder in said cavity covering said first layer and blank; said metal powder having a melting point lower than the thermal degradation temperature of said core; providing a cylindrical plug having opposite ends and its outside diameter so related to the inside diame¬ ter of said casing cavity as to provide a close slip fit, forming a cylindrical cavity in one of said plug ends having a bottom spaced from said other end, the inside diameter of said plug cavity adjacent said bottom there¬ of being greater than at said one plug end; inserting said plug in said casing caviity with said plug cavity facing said second metal powder layer until said plug cavity bottom engages said second layer; applying pres- sure to said other end of said plug thereby to compress said first and second metal powder layers, and heating said casing while maintaining said pressure for a time and at a temperature sufficient to melt said metal pow¬ der, but at a temperature less than the thermal degra- dation temperature of said core, thereby to form a body of molten metal encapsulating said blank; terminating sai pressure and heating and cooling said casing to solidify said metal body thereby to secure said plug and blank in said casing cavity; forming counter-sunk openings in said back side of said casing and said other end of said plug which respectively extend through said metal body to UREOMPI. W1P0 said core; and drilling a die opening through said core communicating between said countersunk openings.2. ' The method of Claim 1 wherein said casing sides are substantially flat and parallel, said first metal pow- der layer being deeper than the height of said undercut and filling the same, and comprising the further step of smoothing the top surface of said first layer prior to placing said blank therein so that said top surface is level and parallel with said back casing side. 3. The method of Claim 2 wherein said blank is ad¬ hered to said top surface of said first metal powder layer. 4. The method of Claim 3 wherein said, casing cavity bottom and plug cavity bottom are flat and parallel with said back casing side. 5. The method of Claim 4 wherein said plug cavity defines an annular flange with the side wall thereof and which is inclined inwardly away from the wall of said casing cavity.6. The method of Claim 4 wherein said blank is a segment of a circle with substantially flat, parallel opposite sides, one of said blank sides being adhered to said top surface of said first layer.7. The method of Claim 1 wherein said synthetic material is chosen from the group consisting of poly- crystalline aggregate of synthetic diamond and a poly¬ crystalline cubic boron nitride.8. A wire drawing die comprising: a metal casing having front and back sides, said front casing side having a cylindrical cavity formed therein, said casing cavity having a bottom spaced from said back casing side and having its side wall undercut adjacent said bottom; a cylindrical plug closely fitted in said casing cavity and having opposite ends; one of said plug ends facing and being spaced from said cavity bottom, said one plug end having a cylindrical cavity formed therein, said plug cavity having a bottom spaced from said other plug end, the inside diameter of said plug cavity adjacent said bottom being greater than that at said one end, said plug cavity bottom being spaced from said casing cavity bottom thereby defining another cavity therebetween which includes said undercut; a body of metal solidified filling said other cavity thereby securing said plug in said casing cavity; and a metal blank having a core formed of synthetic hard, wear-resistant material encapsulated in said metal body with said core concentric with said casing cavity; said back side of said casing and said other end of said plug having countersunk openings therein respectively ex¬ tending therethrough and through said metal body to said core, said core having a die opening therethrough communi¬ cating between said countersunk openings. 9. The die of Claim 8 wherein said casing has sub¬ stantially flat, parallel sides, said blank and core having substantially flat, parallel opposite sides respec¬ tively parallel with said casing sides.10. The die of Claim 9 wherein said blank is a seg- ment of a circle.11. The die of Claim 9 wherein said plug cavity de¬ fines an annular flange with the side wall thereof and which is inclined inwardly away from said casing cavity side wall. 12. The die of Claim 8 wherein said synthetic material is chosen from the group consisting of a polycrystalline _ aggregate of synthetic diamond and a polycrystalline cubic boron nitride.OMP.fa WIP | FORT WAYNE WIRE DIE INC | BIEBERICH P |
WO-1979000212-A1 | 1,979,000,212 | WO | A1 | EN | 19,790,419 | 1,979 | 20,090,507 | new | F16K1 | F16K5, F16K47 | F16K1, F16K5, F16K17, F16L55 | F16K 1/40 | VALVE WITH A HELICAL SPRING AS VALVEMEMBER | A valve for closing or controlling a fluid flow, comprising a control element (4), which for controlling the fluid flow provides for a variable passage area through the device. In order to provide a valve having a simple design and a reliable function, the control member of the valve is constituted by a helix (4), the variable passage area being constituted by the area between the convolutions of the helix. | Valve with a herical spring as valvememberThe present invention relates to a valve for closing or controlling a fluid flow. Many different constructions of valves for closing or con¬ trolling fluid flows are previously known.The object of the present invention is to provide a new valve which has a larger field of application, is easier and cheaper to manufacture and is in certain respects also better than the previously known valves.In order to comply with this object, the valve according to the present invention is characterized in that the variable passage area is con¬ stituted by the area between the convolutions of a helix.In a preferred embodiment of the valve according to the invention this is provided with means for reducing the pressure drop of the fluid flow when this flows through the area between the convolutions of the helix. In a valve of this kind the generation of vibrations and noise in the valve caused thereby are obstructed, which vibrations can arise at great pressure drops over the helix.The valve can be designed so that the convolutions of the helix directly engages each other when the valve is closed, but especially when the valve is designed as a shut-off valve it is preferred to form the con¬ volutions of the helix from rubber or another material.The characteristic of the valve, i.e. the variations of the passage area in relation to the distance between the ends of the helix, can be given substantially any desired function, for example by forming the helix as a conical helix, or by changing the cross sectional size of the con¬ volutions of the helix at different portions thereof.- UREAUO Pl _ , WIPO Λ In an advantageous embodiment of the invention, the helix is provided in a passage-way ofthe valve body of a tap or ball valve in order to provide in the valve a flow control device which is activated when the valve is opened. Thereby, there is provided a combined shut-off and flow control device for for example water pipe .systems.The invention is described in the following with reference to the accompanying drawings. Fig. 1 is a sectional view of a valve according to the invention. Fig. 2 is a sectional view corresponding to Fig. 1 of an other embodiment of the valve according to the invention. Figs. 3a and 3b show different positions of a valve according to the inventio intended to be used as a flow control device. Fig. 4 shows a valve according to the invention designed as a check valve. Fig. 5 shows a further embodiment of a valve according to the invention designed as a flow control device. Fig. 6 is an axial section of a tap valve includin a valve according to the invention.Fig. 1 is an axial section of a valve according to the invention, the device being connected with a pipe 2. The control element of the valve is constituted by a helix 4 having one end connected with a shoulder 6 of the pipe 2 and supporting at its other end a pressure plate 8. The pressure plate 8 constitutes a flow resistance having a predetermined passage area. The fluid flow through the pipe 2 takes place in the direction of the arrows, and thus, the fluid flows between the convo- lutions of the helix. Thereby, the helix will determine the passage are of the valve in dependency of the area between the convolutions. The flow of fluid through the pipe actuates the pressure plate 8 which is exposed to a greater pressure from the fluid when the fluid flow is in¬ creased, so that the plate 8 is forced to the right which in turn bring about a compression of the helix 4. The compression of the helix 4 provides for a reduction of the passage area between the convolutions of the helix in turn providing for a throttling of the fluid flow. When the fluid flow is reduced, the helix forces the pressure plate 8 to the left in the figure, so that the passage area between the convolutions of the helix is increased and also the fluid flow is thereby increased./ U 0 The valve according to Fig. 1 is suitable for being used as an auto¬ matic shut-off valve which is actuated at an unusually great flow through the pipe 2, for example because of a pipe fracture down-stream from the flow control device. If such a pipe fracture takes place, the helix 4 will be compressed to a closed position and will be maintained in this position because of the pressure difference in the pipe at each side of the flow control device.Fig. 2 shows an automatic flow control device which is included in a pipe 10. In the pipe 10 there is provided a plate 12 firmly connected with the pipe wall and supporting one end of a helix 14. Radially out¬ side the helix 14, the plate 12 is provided with passage openings 16. At the end opposite to the plate 12, the helix supports a pressure plate 18, which is guided for an axial movement in the pipe 10. The plate 18 is provided with a central inlet opening 20. The plate 12 as well as the plate 18 form flow resistances having predetermined passage areas for reducing the pressure drop over the helix 14. If said pressure drop is too great, there is created vibrations in the helix in turn leading to noise. The flow control device according to Fig. 2 works according to the same principles as the device according to Fig. i.Thus, the flow control device according to Fig. 2 maintains a constant flow in the pipe by the fact that the passage area between the convo¬ lutions of the helix is reduced when the flow and the pressure on the plate 18 increase so that the flow is again reduced and vice versa.Figs. 3a and 3b show a flow control device corresponding to the device of Fig. 2' positioned in a pipe 22. Thus, the control device according to Figs. 3a and 3b comprises a plate 24 supporting a helix 26 and being formed with passage openings 28 peripherally outside the helix. At the opposite end in relation to the plate 24, the helix 26 supports a pressure plate 30 having a central passage opening 32. The plates 24 and 30 constitute flow resistances having predetermined passage areas for reducing the pressure drop over the helix 26. The flow control device according to Figs. 3a and 3b differs from the flow control de- vices according to Figs. 1 and 2 by the fact that the helix is conical.-BUREAT *OMPI This fact provides that the control device according to Figs. 3a and 3b obtains an other characteristic than flow.control devices having a cylindrical helix. In a flow control device having a cylindrical helix, the variation of the passage area is proportional to the variations of the length of the helix, while a flow control device having a conical helix has another characteristic. Thus, an increased pressure on the plate 30 of the helix 26 will reduce the distance between the ends of the helix by initially compressing the convolutions having the greatest diameter. Thus, a compression of the helix from the position shown in Fig. 3 initially provides for a relatively rapid reduction of the passage area, as the convolutions having the greatest diameter is force against each other, while in the lower control region, i.e. at small passage areas, there is provided a greater accuracy of the control of the flow. By forming the helix in a suitable way with regard to the diameter of the convolutions and/or the sectional size of the convo¬ lutions at different positions of the length of the helix, it is possib to provide a flow control device having any desired characteristic. The plate 24 is provided with a central opening 33 having a relatively smal diameter which provides for a more even passage of the fluid through the control device and obviates the closing of the flow control device at pressure shocks.Fig. 4 shows a device according to the invention which is designed as a check valve. The valve is provided in a pipe 34 and comprises a plate 36 connected with the pipe and having one end of a helix connected thereto. The other end of the helix supports a plate 40. The plate 36 has a central passage opening 42. The plate 40 has less outer diameter than the inner diameter of the pipe 34 for which reason there is formed an annular passage opening 44 around the plate 40. The flow directions through the valve are shown by means of arrows. Thus, it is apparent that the valve according to Fig. 4 is in all essential respects formed in the same way as the device according to Fig. 1, with the exception that the flow directions through the devices are opposite. A fluid flow through the valve in the directions of the arrow forces the plate 40 to the right according to Fig. 4, so that the helix 38 is retained in an extracted position and the fluid flow takes place between the con¬ volutions of the helix. If the fluid flow takes place in the opposite direction or the fluid flow terminates, the plate 40 is moved to the left in Fig. 4 in dependency of the strength of the helix so that the area between the convolutions is closed and a flow in the opposite direction is thereby obstructed. Dependent on the pretensioning of the helix 38 in the direction of contracted position, it is possible to provide for an opening of the valve at any desired flow in the direction to the right or to provide for a closing at any desired flow in the di- rection to the left in the figure.The flow control device shown in Fig. 5 comprises a valve housing 46 having an annular projection 48 and a locking ring 50 positioned in a groove in the housing. In the housing there is provided a conical helix 52 adapted to control the fluid flow through the control device ac¬ cording to the same principles as described above. At its small end, which is positioned up-stream, the helix 52 is connected with a flow resistance 54 in the form of a washer having a cylindrical edge portion 56, said washer being movable to the left in the housing acainst the action of the helix 52. The passage area of the flow resistance 54 is predetermined by the fact that the resistance is formed with two open¬ ings 57. In addition to the flow resistance 54 having a predetermined passage area the flow control device according to Fig. 5 includes a flow resistance having a variable passage area. The flow resistance having a variable passage area comprises a valve means 58 and a valve seating 62 constituted by a conical element 60. The element 60 is by means of an edge flange 64 fixed between the helix 52 and the projection 48. Thus, the valve means 58 is supported by the washer 54 and is moved together therewith, as the washer 54 is moved more or less to the left according to Fig. 5 dependent on the passage of the fluid through the flow control device. Dependent on the position of the washer 54 and thereby of the valve means 58 in relation to the valve seating 62 the passage area through the flow resistance having a variable passage area will variate. Together the flow resistance having a predetermined passage area and the flow resistance having a variable passage area cooperate for maintaining a substantially constant pressure difference over the helix 52 at different flow rates. Thereby, vibrations of the helix 52 and noise accompanying said vibrations will be quite elimi¬ nated in the valve.In spite of the fact that the flow control device according to Fig. 5 includes an extremely well developed control technique, the device consists of simple elements which in a fast and easy way can be mounted without use of screws or other fastening means requiring time for its mounting. This fact is a great advantage. In mounting a flow control device according to Fig. 5 it is only necessary to position the ele¬ ment 60 with its flange 64 in engagement with the projection 48, po¬ sition the helix with the thick end thereof against the flange 64, position the washer 54 with the valve means 58 positioned thereon inside the helix and finally position the locking ring 50 in the groove in the valve housing.Fig. 6 shows a flow control device of the kind shown in Fig. 5 included in the valve housing 66 of a tap valve 68. The valve housing 66 forms the housing of the flow control device, and thus, the elements forming the flow control device according to Fig. 5 are positioned in the passage opening 70 of the valve means 66. Therefore, the different ele¬ ments of Fig. 6 have the same reference numerals as in Fig. 5 with the addition a . The valve means 66 is in a conventional way rotatably positioned in the valve housing of the valve 68, and thus, the valve shown in Fig. 6 constitutes a combined closing and flow control valve. The housing of the valve 68 is provided with openings 72 which allow that the flow control device can be made available for service and/or adjustment in the closed position of the valve means 66.In order to prevent fluid flow through the valve 68 if the valve means should by mistake have been so positioned that the fluid flows in the direction from the element 60a to the washer 54a, there is between said washer and the locking ring 50a provided a further washer 72 having a central opening 74. It is recognized, that fluid flow can take place- U~ m• *7 ■ in the intended direction only when the washer 72 is present, as the washers 54a and 72 thereby are positioned at a distance from each other, but not in the opposite direction, as said washers thereby sealingly engage each other.Also in the embodiments of the device according to the invention de¬ scribed above, a washer of the same kind as the washer 72 can be present.The invention can be modified within the scope of the following claims. For example it can be preferred to provide a valve according to the invention with a control means consisting of a spring thread covered by an elastic material.The flow control device according to the invention is especially well suited for being used in hot water heating systems. To such systems there are connected a number of radiators and in order to provide for a correct functioning of the system .he flow of water to each radia¬ tor has to be adjusted. By providing a valve of the type shown in Fig. 6 in connection with each radiator it is possible to adjust the flow of water to each radiator by positioning a flow control insert in each valve providing for the correct and desired flow through that valve. | C L A I M S1. A valve for shutting off or controlling a fluid flow, character¬ ized in that the variable passage area of the valve is constituted by the area between the convolutions of a helix positioned in a valve housing.2. A valve as claimed in claim 1, characterized by means for reducing the pres-sure drop of the fluid flow at the flowing through the area- between the convolutions of the helix.3. A valve as claimed in claim 2, characterized in that said means comprises a flow resistance having a predetermined passage area.4. A valve as claimed in claim 2 or 3, characterized in that said means comprises a flow resistance having a variable passage area.5. A valve as claimed in claim 3, characterized in that the end of the helix positioned down-stream is non-movably connected with a housing and the end of the helix positioned up-stream is connected with the flow resistance having a predetermined passage area and together therewith is movably arranged in the housing in such a way that the fluid flowing through the housing acts for displacing the flow resistance in a direction for compressing the helix.6. A valve as claimed in claim 4 and 5, characterized in that the flow resistance having a variable passage area consists of a valve means and a valve seat, said means or said seat being positioned on the flow resistance having a predetermined passage area for being dis¬ placed in a direction for reducing the passage area of the flow resistance having a variable passage area when the flow resistance having a predetermined passage area is displaced in a direction for compressing the helix.7. A valve as claimed in any of the preceding claims, characterized in that said helix is of conical shape.-B-O .<&,. V7 8. A valve as claimed in any of the preceding claims, characterized in that the helix consists of a thread covered with an elastic material.9. A valve as claimed in any of the preceding claims, characterized in that the helix is positioned in a passage opening in the valve means of a tap or ball valve for constituting therein a flow control device which is acting when said valve is in its opened position.-BUREAUOMPI | DERMAN K; SOEDERBERG R; SOEDERBERGS ING BYRA; SOEDERBERGS INGENJOERSBYRA AB | DERMAN K; SOEDERBERG R |
WO-1979000213-A1 | 1,979,000,213 | WO | A1 | EN | 19,790,419 | 1,979 | 20,090,507 | new | H04N5 | null | G11B27, H04N5 | G11B 27/00V, G11B 27/026, G11B 27/028, G11B 27/10A1, G11B 27/34, H04N 5/781, H04N 5/937, S11B 27/026 | VIDEO EDITING SYSTEM | A record and playback system for video information, e.g. video frames successively presented at a standard frame rate, each frame having first and second video fields, and for playing back the video information in a desired sequence to produce a video output signal, providing either slow motion or normal motion effects. A frame recorder has a rotatable recording medium (22), first and second transducer means (24, 25) for recording and playing back video frames in recording tracks on the recording medium. and means (27) rotating the medium at frame rate such that a video frame is recorded in each of the recording tracks. A field store (111) can store a field of video information replayed from the recorder. A switch is connected to a field store and to the recorder for providing at the switch output video information from the field store or the recorder in response to a delay field signal. The switch changes switching state and the transducer means are stepped to provide at the switch output replayed video information in the same sequence in which it was recorded or, alternatively, in a sequence different from that in which it was recorded, with the sequence of fields within the frames properly ordered for interlace. The video recorder system also includes a circuit providing a cue display signal (C-2) on a video monitor which is indicative of the progression of the transducer means to successive tracks during both recording and playback. | SLOW MOTION VIDEO RECORDING AND PLAYBACK SYSTEMBACKGROUND OF THE INVENTION The present invention relates to video recorders of the type which provide a relatively limited recording capacity and which are capable of replaying the recorded video information either in real time or in a variable speed, slow motion replay mode. Such recorders are parti¬ cularly adapted for use in televising or recording sporting events where a continuous video recorder of a substantially greater capacity may be used to provide a recording of the entire event. A recorder of the type to which the present invention is directed is selectively employed to record portions of the event which are later replayed , either at normal speed or in a manner to produce a slow motion effect.The standard NTSC color video signal used in the United States consists of a succession of video frames, each frame consisting of two video interlaced fields.each of- which consists of a series of horizontal lines of video information, separated by horizontal line timing.pulses. Each frame contains a field of a first type, termed an odd field, Ξnd a field of a second type, termed an even field. In order to produce the desired interlace between the-two fields of a frame, the beginning of each even field occurs at a time'offset by one half video line time with respect to the horizontal timing pulses, while the beginning of each odd field occurs with no offset. Color video signals include a chroma component.The phase of the chroma component at the end of each field will lag the phase of the chroma at the beginning of the field by 90°. Thus, it is seen there are frames of video information of a first type in which the chroma component varies in phase from 0° to 180° and frames of a second type in which the chroma component varies from 180° to 360°. In order for successful operation of a recorder, the recorder must provide during replay successive frames which alternate in frame type, with each of the frames containing a field of a first field type and a field of a second field type.A typical prior art slow motion recorder is shown in U. S. Patent No.' 3,637,928, issued January 25, 1972, -to Poulett. .The Poulett recorder uses four video recording disc surfaces with four corresponding record/playback heads- to record, respectively, the four fields making up the frames of the first and second frame types. Each of the. recording disc surfaces is rotated at the field rate and, during recording and playback, the record/playback heads are moved to predetermined recording' tracks on the disc sur¬ faces. During playback, the sequence in which the fields- are replayed may be varied in order to produce various slow motion effects.Another recording device is shown in publication B 347,661, published March 16, 1976, under the Second Trial Voluntary Protest Program, with Iyama, et al as inventors. The Iyama, et al recorder records only single fields and reproduces them in such a manner that they are interlaced; into frames for display. A major problem- ith respect to video recorders operating at 3600 r.p. . (the field rate in- the NTSC system) is -the limitation which this imposes on the recorder storage capacity, since only one field can be stored in each recording tra,ck. Another problem with such disc recorders is that excessive wear of the disc and transducer heads may occur over a period of time.U. S. Patent No. 3,518,366, issued June 30, 1970, to Phan, discloses a video recording system capable of reproducing video information in a slow motion format. The Phan system uses a single recording disc which is rotated at the. frame rate (1800 r.p.m.) of the video signal. A plurality of frames of -video information are recorded on one side of the disc in a spiral recording track. . A pair of record/replay transducers cooperate with a single circular recording track on.the opposite side of the disc to construct a single frame from a field which is replayed- from the spiral recording track. This synthesized frame, having identical fields, is replayed a number of times under control of a slow motion.timer in order to produce a slow motion video output signal. The Phan system is somewhat limited in flexibility, however, since it is'capable <J>f providing slow motion reproduction rates only at integer multiples of the rate at which the information is recorded,--U. S. Patent No. 4,058,840, issued November 15, 1977, to Kasprzak, and assigned to the assignee of the pre¬ sent invention, discloses a video frame recorder which. includes control circuitry to re-record a field from one- half of a disc recording track onto the other half of the recording track such that an interlaced frame, consisting of two identical fields, is produced for replay. Although using, a disc frame recorder, the Kasprzak system is not capable of providing slow motion video signals during--- replay.In video recorders of the type to which the pre¬ sent invention is directed, it is advantageous that th operator of the recorder have provided to him a visual indi— cation of the recording operation and, during replay,- a. visual indication of the replay Operation. A recorder of the type to which the present invention is directed permits short portions of a video signal to be recorded and then replayed, with or without an altered time base effect as desired by the recorder operator. This type of recorder typically has a relatively short real time storage capacity and thus video information is continuously recorded over previously recorded video information. When used to provide slow motion instant replay of a sporting event, for example, a recorder of this type will typically be left in the record mode. The operator may note an event of interest to which he may later wish to return. In the past, a recording indicator has typically been provided in the form of a dial arrangement which rotates as the transducer heads are stepped to successive recording tracks.= The operator will know that if the event of interest occurred while the dial .pointer was directed to a certain point on the dial, he may replay the event of interest by operating the recorder during replay- such that the dial pointer again is directed to this point on the dial. With such an arrangement, how- ever, it is necessary for the operator to view the- indicator dial and, simultaneously, the video monitor. The operator must take care, as well, that the re¬ corder not be left in the record mode for a period-- sufficient to result in new video information being- recorded over the video information showing the event of interest. Therefore, the operator must watch the dial pointer closely.and may be distracted ■- and miss an event which he would otherwise prefer to . record. SUMMARY OF THE INVENTIONAccording to the present invention, a slow motion recording and playback system is provided in. which a usage display is generated in the form of a- dot which appears on the video monitor at the per— imeter of the monitor. At the beginning of the re¬ cording process, the dot may, for example, appear at the upper left-hand corner of the screen and, during- recording, the dot will progress in a clockwise manner. around the periphery. The stationary dot will also appear in the upper left-hand corner to indicate the point at which recording began. When recording is terminated, a third dot will appear at the termination point, so that the operator will not continue on be- . yond this point during replay. The system further pro— vides for placing a stationary cue dot at a point along the periphery of the monitor when an event of interest in noted, such that the operator may return to this point later for viewing during replay. mation consisting of video frames successively pre¬ sented at a standard frame rate, each of the frames-- including a first video field of a first field type and a second video field of a second field type, and for playing back the video information in a desired sequence to produce a video' output signal providing either slow motion or normal motion effects when viewed on a monitor, utilizing frame recorder. The 0 frame recorder has rotatable recording medium, trans¬ ducer means for recording and playing back the video frames in recording tracks on the recording medium, and means for rotating the medium at the standard frame rate and for stepping the transducer means- at-' 5 the standard frame rate such that a video frame may¬ be recorded in each of the recording tracks . A field delay means is responsive to the recorder for storing- a fiέld of video information and providing the stored field at its output. 0 Stepping means step the transducer means dur¬ ing playback to recording tracks on the recording medium in accordance with a sequence control signal* A switch means provides video output signals at its switch output and connects the switch output to the - 5 field delay means output or, alternatively, to the frame recorder in response to a delay field signal-— Logic means , responsive to the field reference signal and the playback rate signal, provides the sequence control signal to the stepping means and, further,30- provides the delay field signal to the switch means. The video information is thereby replayed as re¬ corded or in a different sequence from that in which it was recorded, the sequence of fields within the frames of the replayed video information being such35 that it consists of alternately presented fields of a first field type and a second field type.The video recorder and playback system may fur¬ ther comprise means for generating the playback rate signal at a rate which is less than the field rate of the video information which is stored, whereby the replayed video information will provide a slow motion effect when viewed on a monitor. ~~'The video recorder and playback system further includes means for generating a direction indicating signal, with the logic means including means respon¬ sive to the direction indicating signal for altering the sequence control signal. The transducer means may be stepped by the altered sequence control signal to tracks on the medium in a sequence which is reversed from the sequence in which the fields of video in¬ formation were recorded, whereby the replayed video information will provide a reverse motion effect when viewed on a monitor. The video recorder and playback system may further include means for terminating the playback rate signal, whereby the replayed video information will produce a stop-action effect when viewed on a monitor. . The switch means provides its output to a chroma in- verter which inverts the chroma component <zf£ the video signal applied thereto in response to a chroma invert signal. The logic means will supply the chroma invert signal to the chroma inverter, whereby the sequence of frames and sequence of fields within the frames of the replayed video information is such that it con- • sists of alternately presented video frames of a first and second frame type, with each of the frames includ¬ ing a first video field of a first field type and a second video field of a second field type. The video information recorded may be divided into segments with a cue signal means providing a cue signal at selected times during recording of the seg¬ ments of video information. A means for generating a clocking signal as successive segments of video infor- mation are recorded or replayed provides an output to a counter means which cyclically assumes successive count states in response to the clocking signal. A latch means is responsive to the counter means and to . the cue means for storing the count state of the counter means upon receipt of each of the cue signals. Means is provided for generating a cue display signal in response to the latch means whereby the cue dis- play signal may be superimposed upon the video infor¬ mation as it is replayed.BRIEF DESCRIPTION OF THE DRAWINGSFig. 1 is a schematic diagram showing the record— ing system of the present invention, including a moni- tor and control console arrangement, and Fig. 1A is- an enlarged view of the monitor and console;Fig. 2 is a block diagram representation of the recorder and associated control circuitry;Fig. 3 is a schematic representation of the.- time base correction and field store portion of the present invention;.Fig. 4 is an electrical schematic representation? showing the input control and associated logicFig. 5 is an electrical schematic representation showing the sequencing logic;Fig. 6 is a timing diagram useful in' under¬ standing the operation of Fig. 5;Fig. 7 is an electrical schematic representa¬ tion showing a chroma invert control circuitj Fig. 8 is a schematic representation of the^ interface logic circuit;Figs. 9A and 9B, when assembled with Fig. 9A to the left of Fig. 9B, form an electrical schematic represen- tation of the stepper control logic for sequencing the position of the transducer heads;Figs. 10A, 10B, IOC and 10D, when assembled with Pig. 10A above 10B and Fig. IOC above 10D, with Figs. -10A and 10B to the left of Figs. IOC and 10D, form an elec¬ trical schematic representation of the cue display logic;Fig. 11 is an electrical schematic representation of logic circuitry used with the circuit of Fig. 10 for displaying a cue signal; and Fig. 12 is an electrical schematic representation of control logic for controlling the auto search function. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT .Fig. 1 shows the overall recorder system of the present invention. A control console 10 includes the various operator control switches and a cathode-ray tube display 12. The control logic 15 is shown diagrammatically as removed from the console 10, although some of the logic may actually be incorporated within the console. The video- frame recorder 20 includes a two-sided rotatable recording disc 22, and upper and iower transducer means 24 and 25.for recording and playing back video frames in circular record¬ ing tracks 26 on the upper and lower surfaces of disci Th disc recorder also includes a drive motor 27 which provides- a means for rotating the disc 22 at the video frame rate. As discussed previously, the standard NTSC color video signal includes video frames of a first and a second frame type. Frames of the first type include a chroma com¬ ponent the phase of which is 0° at the beginning of the : frame and 180° at the end of the frame. Frames of the second type include a chroma component the phase of which i 180° at the beginning of the,frame and 360° at the end of t frame. Video frames of the first frame type are recorded on the upper surface of the disc 22 by the transducer 24, while yideo frames of the second frame type are recorded on the lower surface of the.disc 22 by transducer 35.Drive motor 27 includes a drive amplifier and a motor feedback tachometer. Means for stepping the upper an lower transducer means to successive tracks 26 on the disc 22 include stepper controllers 30 and 32. The transducer heads are conventional and each includes an erase head gap which precedes the record/play¬ back portion of the transducer head. Each recording surface on the disc 22 is capable of storing a video frame in each of the 300 circular recording tracks 26, thus providing a total of 600 frames of storage, or approximately 20 seconds of video picture information storage in the NTSC system. Camera -35 is one typical source of video information to be recorded. Video information which is stored and played back by the recorder is provided on output 36, typically for use by a television station or network.The video frame recorder system of the present invention includes circuitry for monitoring and displaying a video indication of the progression of the transducers 24 ■ and.25 to successive tracks 26 on the disc 22 during both • the recording process and the playback process. The opera-s.. tor commences the recording operation by depressing an appropriate record switch on the console 10. Successive frames of the video signal will then b recorded alternately on the upper and lower recording surfaces of the disc 22.The transducer heads 24 and 25 are stepped alternately while the opposite transducer head is recording in a fashion such- that heads skip every other track as they move progres¬ sively inward toward the center of the disc. At the outer limit of head motion, after each .of the heads has covered 150 tracks on its associated recording surface, a limit control, such as a photocell detector, detects the position of the heads and reverses the operation of the steppers 30 and 32. At this point the heads will. commence stepping inwardly toward the center of the disc, • with the heads being aligned with the tracks which were skipped during their outward stepping progress. Each trans¬ ducer head will therefore record on the odd numbered tracks as it is stepped radially inward, and will record on the even numbered tracks as it is stepped radially outward. A track counter which is reset by the photocells at the outer head stepping limits will keep track of the movement of the heads to reverse their direction of movement at the inner head stepping limit, causing the heads to step outwardly and record over the previously recorded information on the odd numbered tracks. When the operator presses the recording switch on the console 10, a cue display dot C-1 will appear upon the cathode-ray tube at a point on the periphery of the tub corresponding to the position of the heads at that time. As the recording process progresses, a moving cue dot C-2 will be generated and will leave the stationary dot C-1, • indicating to the operator the progress of the recording operation. The dot C-2 will move in a clockwise fashion around the periphery of the cathode-ray tube display 12 in synchronism with the movement of the transducer heads 24-- and 25 across the recording surfaces of disc 22. The moving dot C-2 will traverse the entire periphery of the cathode-ray tube during one full recording sequence, which is equal to 20 seconds of real time video information. The operator will at the same time observe on the cathode— ray tube the video signal which is being recorded.Should the operator determine that a point of interest has been reached during the recording process, a cue button on the console 10 may be depressed resulting in the generation of a dot C-1' which will momentarily coinci With the progressing dot C-2 but which will be stationary on the cathode-ray tube display, indicating this point of interest. The cue 3ot C-1 will at this point no longer be displayed. When the recording operation is terminated, a further cue mark C-3 will be generated which will remain on the cathode-ray tube, indicating the point at which recording as terminated. The dots C-1 ' and C-3. are- displayed on the cathode-ray tube during the playback of th recorded video information. The moving dot C-2 is also displayed during playback, providing an indication of whic portion of the recorded video information is then being replayed. An auto search mode is also provided, which is initiated by the appropriate control buttons on the console 10 to step the recorder rapidly, such that the dot C-2 is returned to be coincident with dot C-1 or C-1'. The trans¬ ducer heads 24 and 25 are thereby positioned appropriately for replaying the event of interest which was. indicated - by dot C-1 or C-1* .Playback of recorder information from the video recording disc 22 may be accomplished in either the forward or reverse direction and at either normal or slow motion rates. If the slow motion mode of playback is chosen, the rate at which the playback occurs is controlled by a sliding control 37- by which the operator can vary the rate at which the transducers •24 and 25 are stepped across the surfaces of the disc 22. It will be understood that in such a slow motion playback mode the frames of video information will be- provided successively to the cathode- ay tube monitor 12 and to the video output line 36 at the conventional NTSC frame rate of 30 frames per second. The sequence of frames in slow motion playback will, however, include frames having identical video infojrmation in order to effectuate the slow motion playback effect. The details of the operator control of:- the recorder during record and playback are disclosed - more completely in U. S. patent application Serial No. 842,247, filed October 14, 1977, and assigned to the - assignee of the present invention, the disclosure of which is incorporated by reference herein.The signal handling and control logic is shown schematically in Fig. 2. Video information is applied to an input processor 40, which includes a filter 42, a sync strip circuit 44, and a switch 46. The input video is applied to line 48 and is filtered by filter 42 which has a bandwidth of approximately 4.5 MHz. An external sync signal, applied to line 50, may typically be derived from station sync. Switch 46 applies either the input video or the external sync to the sync strip circuit .44 which, in turn, provides a disc sync output on line 52. The sync signal is also applied to the clamp circuit 54 of the modulation unit 56. The modulator 58 is a-standard automatic frequency control modulator which clamps the modulating frequency to a specific reference frequency, typically 7.9 MHz.The modulator output goes to lines 60, 62 and 64 The line 60 is used when it is desired to bypass the recor ing system completely, at times other than during playback as well as during certain test operations. The output of the modulator 56 is also -applied to record/playback ampli¬ fiers 66 and 68. ■ These amplifiers cooperate with trans¬ ducer heads 24 and 25, respectively, during both recording and playback.•Inputs 70 and 72 to the amplifiers control the sequencing and operation of the amplifiers during the recording and playback modes of operation. Equalizers 74 and 76 receive the video outputs from the amplifiers 66 an 68,. respectively, and provide these video outputs to a switch 78. Equalizers 74 and 76 equalize the reproduced video signal such that the correct amplitude and phase response is obtained during playback. Switch 78 switches- in synchronism with the alternating operation of the trans ducer heads 24 and 25 during both recording and playback- The output from switch 78 goes through switch 80 to a demodulator and filter circuit 82.Switch 80 will be switched into its lower switch ing position during playback, and will be switched into its upper position during recording so that the monitor may be provided with the video signal at the same time that it is recorded onto the disc 22. A dropout detector circuit 84 detects when a portion of the video signal is missing and provides an output to line 86 when this occurs to initiate drop out correction, as discussed below. The filters, modulators, demodulators, amplifiers, dropout detector, and equalizers, are all well known in the art and are inco porated into most prior art video disc recording systems. Also standard in video disc recorders is a servo control for controlling rotation of the disc 22. This control includes the motor 27, having a tachometer, the servo circuit 88, and drive amplifier 90. Control logic circuit 92 provides control signals to the aforementioned circuitry to control circuit operation. The manner in which the control logic 92 controls operation of the system is determined by input information applied through the console 10.The video output from the recorder is applied through the demodulator filter circuit 82 to a time base corrector circuit 94, the details of which are discussed below. This circuit performs a number of functions, including correcting for time base errors and, simultan¬ eously, providing a slow motion playback sequencing of reproduced video fields. The time base corrector circuit 94 includes digital storage, termed a field store, for storing video fields as required to produce a slow motion- effect. The time base corrector circuit 94 includes cir¬ cuitry which adjusts the type of frame and field provided at its output such that the frame and field types will agree with those which are required for proper synchronization wfth the station signal. Time base corrector 94 also includes a dropout circuit which corrects the video inform^- ation in the event of occurrence of a dropout condition. The corrected video, provided at output line 96, is supplied for use as the television station signal. The corrected video is also supplied to a cue video amplifier 98 which adds a cue display signal from the control logic 92 on line 100 and to produce a- control display video output on line 102 for display by the cathode-ray tube included in the - control console 10.Control logic 92 provides four control signals to the time base corrector circuit 94. A delay line command signal is provided when an odd field is retimed such that it becomes an even field. The VCO invert signal is provided to a voltage controlled oscillator in the time base corrector to compensate for discontinuities in the stripped burst signal to which the time base corrector circuit is locked. The chroma invert signal controls inversion of the chroma component of the output video signal by the time base cor- rector in order to maintain the proper chroma phase rela¬ tionship. The delay field signal controls insertion of a field store into the video signal channel in the time bas corrector when the recorder is in the slow motion or freeze modes of operation.The upper and lower stepping control circuits 30 and 32 are identical and are well known in the art. In general they each comprise a stepping motor which drives a mechanism, such as a lead screw, to move the transducer heads radially along the recording surfaces of the disc 22. Each stepping motor includes a plurality of drive coils which are selectively energized in a predetermined sequence to rotate the lead screw driving mechanism,.Reference is now made to Fig. 3 in which the time base corrector circuit of the present invention is diagram— matically illustrated. Video information is applied to an input video processing circuit 103 from the demodulation an filtering circuit 82 (Fig. 2) . The burst portion of the video signal is stripped by the circuit 103 and applied -to the phase locked loop circuit.104. A phase detector 105 compares the output phase of the voltage controlled oscil¬ lator 106 to the stripped burst signal to hold the oscil¬ lator output locked to the burst signal. A VCO invert command controls switch 107 to invert selectively the voltage controlled oscillator 106 output. Inversion of the oscillator output is necessary where a single frame is played repetitively, since this will result in a dis¬ continuity in the burst portion of the video signal in each successive frame. The output of oscillator 106 on line 108 is a 14.3 MHz clock signal which clocks the time base corrector circuit.An analog to digital converter 109 converts the video information into digital form and supplies it to a four line storage circuit 110. Circuit 110 corrects slight time base fluctuations in the reproduced video signal and . provides the time base corrected video signal at its output to a field store circuit 111 which is capable of storing an entire field of video information. The output of circuit 110 is also applied to line 112 which provides a bypass around the field store circuit 111 to a switch 113. The output of the field store 111 is applied to a one line delay 114 and also to a line 115 which provides a bypass around the delay 113 to a switch 116. The switching state of switch 116 is controlled by a delay line command on line 117, while the switching state of switch 113 is controlled by a delay field command signal, also termed a READ FIELD STORE (R.F.S.) on line 118.If it is desired to display repetitively a single field, for instance, the frame in which this field appears' will be repetitively replayed from the disc recorder and processed through the various circuits until it reaches the output of circuit 110. Assuming that the first field of'- the frame is to be supplied to the monitor repetitively, the switch 113 will initially be switched to its upper- switching position, providing the first field at its output. Simultaneously, the first field will be loaded into the - field store 111. As the second field of the frame is sup¬ plied to the input of the field store 111 and also to line 112, the switch 113 will be switched into its lower switch¬ ing position and, neglecting for the moment the operation of delay 114 and switch 116, the first field of the frame will then be read out of the field store 111 and applied to switch 113. After this operation is complete, the switch 113 will again be switched to its upper switching position,-- as the first field of the frame is supplied to line 112. Thus, by actuation of the switch 113, the first field of the frame will be repetitively applied via switch output to line 120. The video information in digital form is clocked into and out of the field store 111 in synchronism with the station reference timing. Thus a field which was originally odd as recorded onto the disc will be read out of the field store 111 at the appropriate time to change the field into an even field if an even field is required by the station reference timing. . A delay line command on line 117 will result in the switch 116 being switched into its upper switching stat and the output of the field store 111 delayed by one hori¬ zontal line time. It will be appreciated that adding the one line delay will result in each line of the delayed fiel being shifted downward on a monitor by a distance equal to the vertical inter-line spacing of a field. Since a field in the NTSC system includes 262 1/2 lines of video inform¬ ation, changing an odd field into an even field will result in a vertical shift of the horizontal video lines on the monitor in a direction which is opposite to the vertical shift experienced when an even field is changed into an odd field. In either case, the vertical shift experienced will be equal in magnitude to one-half of the vertical inter-lin spacing of a field.To avoid shifting lines of video both upward and downward on the monitor as successive frames of video infor ation are reconstructed, one line delay 114 is inserted int the video charihel by switch 116 as the even fields are- changed into odd fields and the one line delay is removed- as the odd fields are changed into even fields. This will, in turn, result in a shift of video lines on the monitor- which is always downward. Thus the undesirable jumping effect between frames which would otherwise result is- eliminated.A one line- delay 132 is provided and is switched into the signal path to repeat the previous line when a dropout condition is detected. The video signal is then- -. provided to a chroma inverter 134 which separates the chrom component from the balance of the video signal and inverts it when necessary. As previously discussed, video frames in the NTSC system are either of a first type, in which the chroma phase goes from 0° at the beginning of the frame to 180° at the end of the frame, or of a. second type, in which the chroma phase goes from 180° at the beginning of the frame to 360° at the end of the frame. It will be appreci-; ated that conditions will arise, especially in slow motion or freeze modes of operation, in which the chroma phase of the video signal provided .on line' 120 will be opposite that required for proper chroma phasing with the station or net¬ work signal. A CHROMA INVERT signal is generated when necessary by the control logic, resulting in the chroma component being inverted. The chroma inverter circuits are well known in the art. After correcting for chroma phase dis¬ continuity, the video signal is converted to analog form by means of converter 138, and processed by circuit 140. Video processing circuit 140 adds sync and burst signals to the- reproduced video signals. The sync generator and timing- reference generator circuit 141 provides reference sync and reference 14.3 megahertz signals to the storage controller- 142, which in turn controls operation of circuit 110. Cir¬ cuit 141 supplies an advanced sync signal to the servo loop which rotates the recording disc. The advanced sync signal is used during playback to compensate for timing delays in the video processing circuitry by reading recorded video advanced in time by an appropriate period. Circuit 141 also provides the necessary timing signals to the field store clock 143, delay 132, chroma inverter 134, converter 138, and processing circuit 140.Reference is now made to Fig. 4 which shows a por— tion of the control logic of the present invention. ' The circuitry.of Fig. 4 includes a plurality of switches labeled N, SM, FZ, R, >, , Q, A, S , -^, < <^ , FRAME, EDIT, and S'BY. Each of these switches is located on the console 10 (Fig. 1) and each of these switches is connected to ground. An asterisk is associated with the right-hand side of each switch and indicates that a bias potential is applied to this side of the switch via a pull-up resistor. The output from each switch will therefore be high whenever the switch is open and will be at ground potential only when the switch is closed. Similarly, light emitting diodes are labeled as FRAME, EDIT, S'BY, SERVO, TALLY, F D^=- , REV ^ REC, FZ, S, N, and RST. Each of these light emitting diodes has associated therewith a driver which will hold the anode of the diode at ground until the associated switch is closed. When a function is selected and a switch closed, a appropriate light emitting diode will receive current through an associated driver. It should be noted that asterisks are associated with the anode of each of the ligh emitting diodes, indicating that a DC bias potential is applied at this point through a pull up resistor to assist the driver in energizing the diode. The light emitting diodes are positioned on the console 10 (Fig. 1) and provid an indication of the selected function.A pair of latches 144 and 146 are provided in the circuit in order to debounce the switch outputs. Latch: 144 is normally disabled by a high output from AND gate 148- to the data disable input. When one of the switches asso¬ ciated with latch 144 is closed, the AND gate 148 will pro¬ vide a low output to latch 144, thereby permitting the latc to change state in response to the signals supplied to its D_, D,, D2, and D^ inputs. The Q., Q,, C and Q3 outputs- of latch 144 will latch to the signal level provided at inputs DQ, D, , D_ and D~, respectively. The latch 144 is clocked by the signal, which is a field reference signal.- occurring every 1/60 of a second. Once a switch is depressed and latch 144 changes state, it will not be enabled by a clock signal to change state until the next successive FN pulse. By the time this occurs, any trans¬ ients occurring as a result of switch bounce will have died out.The functions controlled by the switches are as follows. The'N switch provides for operation of the recorder at the normal video rate. The SM switch provides, for slow motion operation of the recorder. The FZ switch is a freeze switch which causes the recorder to replay only a single field or frame. Subsequent actuation of the FZ switch will cause the recorder to replay each successive field or frame, also in a freeze mode. The R switch is the record- function switch. The~!> switch controls forwardO.MPI Φ?Λ'AT10 playback,- while the -<L switch controls reverse playback. The Q switch causes a cue dot to be displayed upon the cathode-ray tube monitor 12 (Fig. 1) . The A switch is an auto search function switch. The RST switch is a reset switch which is used to return the transducer heads to their initial positions at the periphery of the recording disc, in the event that they should somehow become unsynchronized from the system controls.The r ^ switch is a fast forward search switch, and the ^ ^switch is a fast reverse search switch. The last two switches control manual searching in .which the transducers are rapidly stepped to successive track loca— ' tions under operator control. The FRAME switch, if closed, will cause the recorder to play back a complete frame of - two. interlaced fields. Normally -this switch will not be closed when slow motion operation is desired, since the picture content of two successive fields may differ suffi¬ ciently to cause a jitter effect as these fields are repetitively displayed. The EDIT switch permits a portion of a video input signal to be recorded onto the disc. When the EDIT switch is closed, the operator -may record- ideo- information onto the disc by closing simultaneously the N switch and the R switch. As soon as these switches are- opened, recording.will cease. By closing the FZ an R switches simultaneously, single frames of video information- will be recorded. The S'BY switch is a stand-by switch, which will cause the transducer heads to be retracted from the surface of the video recording disc.AND gate 150 provides a low signal to latch 144 whenever either the N switch or the switch is closed.This insures that recording is always accomplished at normal, speed. Similarly, whenever the A switch, the RST switch- the^>\> switch or the <<1switch is energized, the AND gate Ϊ52 will provide a low signal to latch 144. AND gate 152 therefore assures that after the auto search, the reset, the fast forward search, and the fast reverse search functions are chosen, the recorder will be left in the freeze mode of operation. NAND gates 154 and 156 form a flip-flop which is set or reset depending upon whether the forward or reverse mode of operation is chosen. AND gate 158 will set this flip-flop when either the R switch or the > switch is closed. Similarly, the flip-flop will be reset when the T switch is closed.Latch 146 is a momentary latch arrangement. The Q.-Q outputs will only go low for as long as the switches associated with latch 146 are closed. Latch 146 is also clocked by a field rate signal to debounce the switch outputs.The S output from AND gate 162 is a playback rate- signal which controls the rate at which successive fields- of video information are reproduced, both in the normal and slow motion modes of operation. A slow motion oscillator 164 provides an oscillator output on line 166 which is controlled in frequency by the setting of variable resistor 168 and can be varied from 960 Hz to 0 Hz. The lever 37 (Fig. 1} on the console 10 of the recorder unit provides a means of adjusting resistor 168. A divide-by-16 counter 170 supplies pulses to line 172 which vary between 60 Hz and 0 Hz. These pulses are applied to the clock input of flip- flop 174, via AND gate 176 when the FZ switch is not closed. Each of the pulses on line 172. will cause the flip-flop 174 to set since the D input of the flip-flop is attached to a DC bias. The next successive frame pulse F will reset the flip-flop 174. The monostable multi-vibrator 178 will the - supply a pulse, via AND gate 180, to the S output.It will be appreciated that should the reset and clock inputs of the flip-flop 174 receive pulses simul¬ taneously, the desired pulse output from the flip-flop will not occur. In order to avoid this situation, OR gate 182 will provide an enabling input to the multi-vibrator 184. If these pulses occur simultaneously, 'the multi-vibrator 184 will apply an output to OR gate 186 and this will, in turn, cause the flip-flop 174 to be set. The OR gate 186 will also maintain the flip-flop 174 in a set state when- ever the normal mode of operation is selected. The pulse output from the flip-flop 174 will, therefore, be synchron¬ ized with, the field rate signals F .Fig. 5 illustrates a portion of the logic cir-5 cuitry controlling the sequencing of the playback process. A flip-flop 188 provides an A output which is indicative of the type of field required by the station timing. Simi¬ larly, a flip-flop 190 provides a B output which is indica¬ tive of the type of frame required by the station timing.10 -Flip-flops 188 and 190 are clocked by a field reference signal and flip-flop 190 -receives a frame reference signal on its D input. ' Field reference pulse F„ occurs at the field rate and is approximately 40 microseconds in duration. Thus flip-flops 188 and 190 specify by their outputs the-15 type of frame and field which must be provided by the recorder in order for the recorder output to be used by the- station.Flip-flops 192, 194, 196, and 198, provide C* , D', C and D signal ojitpύts, respectively. Flip-flops 192— •20. 198 specify the type of frame and field which is presently being provided by the recorder. The difference in the states of the flip-flops 192-198 with respect to flip-flops 188 and 190, therefore, determines the processing which must be performed upon the playback frames and fields in order to25 provide the desired types of frames and fields at the' recorder output. The S pulse signal is applied through INVERTER 200 to clock the flip-flop 192 and through AND gate 202 to clock the flip-flop 194. It will be recalled from the discussion above with- respect to Fig. 4 that the30 s pulses are provided at the'rate at which successive recorded fields are to be replayed. The Q output of flip-- flop 192 is applied to an EXCLUSIVE OR gate 204 along with a F/R signal. EXCLUSIVE OR gate 204 will enable the AND gate 202 only on alternate S pulses so that the flip-flop 19435 will change output states in synchronism with the flip-flop 192, but.-at half the rate. The F/R signal indicates whether the forward or reverse mode of operation has been selected and is derived by circuitry described below.The flip-flops 196 and 198 are clocked by the field pulses and assume the state of flip-flops 192 and 1945 respectively, but with a one field or frame delay. Stated another way, flip-flop 196 will assume the state which flip flop 192 had previously assumed during the previous field interval. Similarly, flip-flop 198 will assume the state which flip-flop 194 had assumed during the previous frame10 interval. OR gates 206 and 208 and INVERTERS 210 and 212 are enabled by the N signal to set and reset flip-flop 192 in synchronism with flip-flop 188 when the normal mode of operation is selected. The flip-flops 196 and 198 provide C and D signals which indicate the field and frame typ15 being read out of the field store, while the flip-flops 192 and 194 indicate the field and frame type being read directly from the video disc.EXCLUSIVE OR gate 214 enables AND gate 216 to provide an R.F.S. signal (read field store) to the switch20. 113 (Fig. 31 when it is desired to read video information •out of the field store.- AND gate 218 provides the delay line command which determines the switching state of switch 116 (Fig. 3) . Both of these outputs are in turn enabled only when the play command (P.CMD.) signal is present.25 Flip-flop 220 provides a U/L output which deter¬ mines whether a track on the upper surface of the recording disc or a track on the lower surface of the recording dis is to be read. Flip-flop 220 is also toggled during recording to control the surfaces upon which the frames of30 video information are recorded. The read command (R.CMD.) is applied to AND gates 222 and 224 and, in conjunction wit the U/L and U/L signals, specifies whether the upper surfac of the disc (R.U.) or the lower surface of. the disc (R.L.) is to be read. 35 AND gates 226 and 228 provide signals to control erasing on the upper surface of the disc (E.U.) and on the lower surface of the disc (E.L.) under control of the eraseOMPI . command signal (E.CMD.). As discussed previously, each of the transducer heads includes an erase gap which slightly precedes the recording gap of the head and which erases previously recorded video information from the recording track prior to the recording operation. Separate control of the erasing function is required in order to terminate erasing slightly before the recording process is terminated. This, in turn, is necessary in order to prevent small unrecorded gaps on the recording tracks. A chroma invert circuit is responsive to a plural¬ ity of signals and provides a chroma invert signal (CHROMA-INV.) at its output when it is necessary to invert the chroma phase of a frame which is replayed by the recorder. The chroma invert circuit is shown in greater detail in Fig. 7.Fig. 6 illustrates the respective timing between the signals generated by the circuit of Fig. 5. Note that the C and D signals lag the C and D1 signals by one field time. Note further that the C signal will change* state. only upon the occurrence of an S pulse. The D' signal changes state on each alternate S pulse. A pair of time lines marked as S. U. and S. L. show' the points in time at which the upper and lower transducer heads are stepped, respectively. These do not correspond to a specific signal in the circuit of Fig. 5. Note that the upper head will be stepped on negative -going transitions of the U/L signal,-- while the lower head will be stepped on the positive going transitions of the U/L signal.Reference is now made to Fig. 7, illustrating the chroma invert circuit of Fig. 5 in greater detail. TheCHROMA INV. signal is provided by OR gate 230 via INVERTER231 unless AND gate 232 is disabled by either the R.CMD. signal or the FRAME signal going low and causing the output of AND gate 234 to go low. Should the output of AND gate 234 go low, AND gate 236 will be enabled, via INVERTER 238, such that the CHROMA INV. signal is controlled by the VCO INV. The VCO INV. signal will, in turn, be high when¬ ever the B and U/L signals are equal in value. Fig. 8 illustrates the interface logic whic;n pro vides many of the control signals needed for operaticm. Most of the input signals are received from the controller circuitry of Fig. 4. Flip-flops 240 and 242 and associate circuitry are provided to control resetting of the trans¬ ducer heads to their initial positions on the outer record ing tracks when the reset function is selected. The ϋnput UO is supplied by a photocell at the outer track position of the upper transducer head and the input LO is provided from a photocell at the outer track position of the lower transducer head. The NAND gate flip-flops 244 and 245 wil be set as the heads with which they are associated reach their respective outer track positions. When both of the heads have reached their outer track positions, the U3 and LD signals will go low and NAND gate 248 will reset flip- flops 240 and 242.'The U/L signal is applied to line 250 and asses to the U/L' and U/L' outputs via NAND gates 252 and 254, except when modified by oscillator 256. When any of the ASR, -<<:, ASF, and ->- signals go low, the oscillator 25 which provides an output at approximately eight times the frame rate of the video signal, will be switched on. Additionally, the oscillator 256 will be switched on by flip-flop 242 when the reset- mode of operation is selected A low signal on the output of AND gate 258, designated SCH will switch on the oscillator 256. The frequency of the oscillator output on line 260 is divided by two by flip-fl262 and the resulting signal applied to the U/L' and U/L* outputs via NAND gate 254. The U/L' signal controls the stepping of the transducer heads. The effect of the oscil lator circuit is to cause the transducer heads to step at approximately four times their normal stepping rate when the auto search, reset, fast forward or fast reverse func¬ tions are chosen. Flip-flop 264 is set by AND gate 266 when the forward direction of operation is selected. It will be noted that all of the reverse functions, including the reset function, will override the forward functions, causi the flip-flop 264 to be reset on the F/R CK pulse. The record—command, R.CMD., is provided by flip-flop 268 and is ■ generated by the comparison of the D1 signal with the U/L signal in EXCLUSIVE OR gate 270. AND gate 272 provides the erase command signal, E.CMD., on its output and under con¬ trol of the flip-flop 274, terminates the erase operation prior to the termination•of recording to insure that no blank portions of the recording track on the disc remain- after a record operation. NAND gate 276 and' INVERTER 278 provide the play command-,- P.CMD. The flip-flop.274, in conjunction with the. ssociated gating, also provides the „ and FN signals. The RETRACT signal is provided whenever the stand-by mode of operation is selected, as indicated by the S'BY signal, to cause the transducer head to be removed from the disc recording_surfaces.Reference is now made to .Figs. 9A and 9B which, when assembled with Fig. 9A to the left of Fig. 9B, illus— * trate schematically the circuitry which controls the means for stepping the transducer heads 24 and 25 (Fig. 1) across the recording surfaces of the recording disc during the recording and playback modes of operation. As mentioned . previously, movement of the transducer heads may be effectu¬ ated by means of stepping motors which rotate threaded shafts upon which- the transducer heads are mounted. As the stepping motor associated with a transducer head is rotated to successive positions, the associated transducer head will be moved to successive tracks on the recording disc. - Outputs Ul, U2, U3, and U4 are provided to the stepping motor associated with the upper transducer head. Similarly, outputs Ll, L2, L3, and L4, are provided to the stepping motor associated with the lower transducer head. The U3 and U4 signals are the inverse of the Ul and U2 signals, while the L3 and L4 signals are the inverse of the Ll and L2 signals. The direction of rotation of each motor is dependent upon the phase relationship of the signals applied to the motor. As an example, Ul will initially go high causing the motor to rotate incrementally in a forward direction. U2 will then go high, causing the motor to rotate an additional increment in the forward direction. will then go low, causing a third increment of rotation i the forward direction. Finally, U2 will go low and the motor will be rotated one increment further in the forwar direction. It is seen, therefore, that the U2 signal lag the Ul signal by 90°. If it is desired to rotate the mot in the reverse direction, the phase relationship between the Ul and U2 signals will be reversed such that the Ul signal will lag the U2 signal by 90°.In order to provide the proper phasing between the Ul and U2 signals and the Ll and L2 signals, flip-flo 280, 282, 284, and 286 are provided. Flip-flops 280 and284 are clocked by the U/L1 and U/L' signals, respectivel As can be seen, EXCLUSIVE OR gates 288 and 290 cross coup the Q outputs of the flip-flops to provide for alternate state change by these flip-flops. The phasing between th W signal from flip-flop 280 and the Y signal from flip-fl 284 is determined by the F/R signal which is applied to EXCLUSIVE OR gates 288 and-290. Each time the X and Y signals change state, the associated stepping motor would be stepped by an amount sufficient to move the transducer head associated therewith to the'next recording track. A discussed previously, however, the recording format used the present invention is one in which each transducer, hea is stepped sequentially to every other recording track on the recording disc during the inward movement of the tran ducer head and each head is stepped to the intermediate recording tracks during the outward movement of the trans ducer head. In order to provide for stepping of the moto by two increments such that every other track is recorded or played, flip—flops 282 a d' 286 provide X and Z signals respectively, which are timed by monostable multi-vibrato 292 and 294. Thus the X signal will follow the W by a pr determined time delay, and the Z signal will follow the Y signal by a predetermined delay in order to provide the double stepping action of the transducer heads. The W signal is provided on line 296, the X sig¬ nal is provided on line 298, the Y signal is provided on line 300, and the Z signal is provided on line 302, to the stepping motors by way of circuitry to be discussed below.. Additionally, the X signal is provided on line 304 and the Z signal is provided on line 306 for use by circuitry which, specifies whether the odd or even numbered tracks on the disc are to be played or recorded.Monostable multi-vibrators 308, 310, 312, and 314 control EXCLUSIVE OR gates 316 and 318. EXCLUSIVE OR gate 316 will invert the X signal output on line 298 afte a period of time determined by the multi-vibrators 308 and 310. This tends to reverse the operation of the stepping motor momentarily, thus providing a breaking action -for the step- ping motor which eliminates over-shooting of the desired track location. Multi-vibrators 312 and 314 provide an identical control operation in conjunction with EXCLUSIVE OR gate 318.Application of the W, X, Y, and Z signals to the - stepping motors is accomplished under the control of the data selector 320. Selector 320 will' provide the Xfi, X,, X_, and 3 inputs to its ZQ, Z_, Z2, and Z_ outputs,, respectively, when the A control input is high. Similarly r selector 320 will connect the Yfl, Y, , Y?, and Y- inputs to its Z , Z,, Z_, and Z, outputs, respectively, when it's B control input is high. The A and B controls for the selec¬ tor 320 are provided by the F/R and R/F signals, respec¬ tively. As is clear, when the forward mode of operation is selected, the W signal will appear at the output Z-, the X signal will appear at the output Z1, the Y signal will appear at the output Z_, and the Z signal will appear at the output Z_. When the reverse mode of operation is selected, the W signal will appear at output Z-, , the X signal will appear at output Z . t the Y signal will appear at output Z_, and the Z signal will appear at output Z_. The outputs of the selector 320-are applied to the stepping motors via AND gates 321, 322, 323, and 324. ' These AND gates are controlled by the UD and LD signals to disable operation of the stepping motors when the transducer heads are returned to their outermost position after the reset function is selected. A latch 325 controls operation of EXCLUSIVE OR gate 326 which provides an additional single step rotation of the stepping motor, independent of the W and x stepping signals, when the upper transducer head has reached the end of its range of travel, either at the inner or outer recording track on the upper surface of the disc. This additional step provides for stepping of the transducer hea to the tracks on the disc which were skipped during the previous pass of the transducer head across the disc sur¬ face. Similarly, flip-flop 327 controls operation of an EXCLUSIVE OR gate 328 to provide for a single step at each end of the range of movement of the lower transducer head. The photocell adjacent the outer track for the upper trans¬ ducer head provides a signal on-line 330 when the upper transducer head has reached its outer limit. A counter, no shown, is counted up as the upper head is stepped to suc¬ cessive tracks. When the counter reaches a predetermined count, the upper head will have been stepped to its inner most recording track. The counter will then apply a low signal to line 332. Similarly, the photocell and counter associated with the outer and inner positions, respectively of the lower transd cer head provide signals on lines 334 and 336, respectively, when the limits of travel of the '. lower transducer .head are reached. The signals on lines 330-336 are then combined with the W, X, Y, and Z signals to gate the flip-flops 325 and 327 on and off in dependence upon- the direction of movement of the transducer heads whic has been selected.,'Figs. 10A-10D, when assembled, illustrate the cue display logic of the system of the present invention. Cue location binary counters 338, 340, 342 and 344, when enable by low going signals on their CI inputs, will count the U/L pulses provided to their clock inputs. The negated carry oυt CO-.output of counters 338 and 342 provides the carry in CI inputs for counters 340 and 344, respectively. Counters 338 and 340 are connected to count in tandem such that their outputs, indicated as LOC. n and LOC. ^, provide an indication of the X coordinate on a monitor of a cue dot corresponding to the track which is currently being recorded or replayed on the recording disc. Similarly, the counters 342 and 344 are connected to count in tandem such that their outputs, indicated as LOC. Y- and LOC. Y, , provide an indica— 0 tion of the Y coordinate on a monitor of a cue dot corres¬ ponding to the track on the recording disc which is cur¬ rently being recorded or replayed. The U signal is supplied' to the up/down inputs of the counters in order to cause them to count forward or backward in dependence upon the 5 direction of operation of the recorder.The XC and ΫC signals control operation of the counters such that the counters 338 and 340 will count up to 86 while the count state of counters 342 and 344 remains 0. The counters 342 and 344 will then'count up to 64, while 0 the count state of counters 338 and 340 remains 86. The counters 338 and 340 will then count down from 86 to 0, while the count state of counters 342 and 344 remains 64. Counters 342 and 344 will then count down from 64 to 0, while the count state of counters 338 and 340 remains at 0 5 As will be understood, therefore, the count in the counters will define, in Cartesian coordinates, a rectangular path around the periphery of the cathode-ray tube display. The XC and ΫC signals are generated by the circuitry of Fig. 11, described below. 0 Latches 346 and 350 will store the output of the counters upon receipt of a strobe pulse' on line 352. When the- recording operation is initiated, the R signal will go low and monostable multi—vibrator 354 will cause NAND gate 356 to provide a strobe pulse to counters- 346 and 350. A strobe-- pulse will also be provided by NAND gate 356 when the cue switch is depressed, causing the Q signal to go low. When the record operation has terminated, the strobe signal will be removed from line 358 causing the counters 360 and 362 to store the coordinate counts of the counters 338, 340, 342, and 344 at the point at which recording'.is terminated It will be appreciated that the instantaneous count in counters 338, 340, 342, and 344 will be an indica tion of the track on the recording disc which is currently being recorded or replayed. It will be noted that the counters have a total of 300 unique counting states. Sinc the counters are clocked by the U/L' signal at 1/2 the fra rate, each of the 300 counting states will correspond to t of the 600 tracks on.the recording disc.The outputs from the counters and latches are multiplexed to digital-to-analog converters 364 and 366, which apply analog signals to output lines 368 and 370, respectively. The multiplexing operation is controlled by the Dl, D2, and D3 signals. Each of the Dl, D2, and D3 signals will go low for one field in a four field sequence During the fourth field time, none of the Dl, D2, and D3 signals will be low. When the Dl signal goes low, latches 368, 370, and 372 will provide the instantaneous count of the counters 338, 340, 342, and 344 to the converters 364 and 366. When the D3 signal goes low, the'latches 360 and 362 will provide the count stored therein to the converter 364 and 366. Since the latches 360 and 362 will be strobe o during the entire recording process, this count will on differ from the instantaneous count of the counters after the termination of recording. When the D2 signal goes low the latches 346 and 344 will provide the count stored ther in to the converters 364 and 366. Counters 346 and 350 wil initially contain a count corresponding to the cue display of the tracks upon which recording was initiated. If an event of interest should be noted during the recording process, however, and the CUE control on the console depressed, the CUE signal will go low, once again enabling latches 346 and 350 to store the instantaneous count of t counters. The latches 346 and 350 will thereafter provide an indication of the tracks corresponding to the event of interest. It will be noted that-the initial recording cue display will be lost. However, by providing additional latching circuitry, display of both the initial recording position and the event of interest may be accomplished. The analog outputs 368 and 370 from the D to A converters 364 and 366 are supplied to amplifiers 372 and 374. Switches 376, 378, -380, 382, 384, and 386 will demul¬ tiplex the amplifier outputs under control of the Dl, D2, and D3 signals. Each switch will connect its data input to its data output upon receipt of a high signal at its control input. Capacitors 388, 390 and 392, will therefore be charged to potentials which are proportional to the X coordinates of the cue display dots. Similarly, capacitors- 394, 396, and 398 will be charged to potentials which are proportional to the Y coordinates of the cue display dots. A ramp function Vχ is provided to line 400. The Vχ signal on line 400 increases linearally from 0 to a predetermined potential level during each field interval.- A ramp function Vγ is applied to line 402. The Vy signal on line 402 increases from 0 to a predetermined potential level during each horizontal video line time. The signals V and Vγ are synchronized with the video being displayed to the control monitor. Comparators 404, 406, and 408 compare the X coordinate voltages from capacitors 388, 390, and 392 to the signal on line 400 and, when, the potentials are equal, trigger the associated one of mόnostable multi-vibrators 410, 412, and 414. Similarly, the comparators 416, 418, and 420 trigger the monostable multi-vibrators 422, 424, and 426, when th signal on line 402 and the potentials stored in capacitors 394, 396, and 398 are equal.When the multi—vibrator 410 triggers simultane¬ ously with the multi-vibrator 422, the NAND gate 428 pro¬ vides a low signal on its output, indicating that the timing is correct for display of the first cue dot. When the multi-vibrator 412 and the multi-vibrator 424 trigger simultaneously, NAND gate 430 will provide a low signal on its -output -indicating that the timing is proper for display of the second cue dot. Finally, when the multi-vibrator 414 and the multi-vibrator 420 fire simultaneously, NAND gate 432 will provide a low signal on its output, indicat that the timing is correct for display of the third cue dNAND gate 434 and INVERTER 436 will provide a CUE display signal when any of the cue dots is to be displayed.Fig. 11 illustrates the decoder logic which is used to provide the XC and ΫC signals and the U signal to the counters in Fig. 10. Fig. 11 also illustrates the lo for deriving the Dl, D2, and D3 signals from the field an frame signals A and B, respectively. The outputs from counters 338 and 340 in Fig. 10 are applied to NOR gate 4 and, with some inversion to NOR gate 494. Similarly, NOR gate 496 receives the outputs from counters 342 and 344, while the NOR gate 498 receives these outputs with one bi inverted. NOR gate 492 will provide -a high output when t X coordinate counter state equals 0; NOR gate 494 will pr vide a high output when the X coordinate counter state equ'als 86; NOR gate 496 will provide a high output when t Y coordinate counter state equals 0; and NOR gate 498 wil provide a high output when the Y coordinate count equals Thus the NOR gates 492-498 define the corners of the rectangular path traversed by the cue dot on the cathode- tube monitor during recording and playback- The U output signal controls whether the counters count up or downReference is now made to Fig. 12 which illustra the circuitry controlling the auto search mode of operati When in this mode of operation, the means for replaying^ recorded video will be returned to the record location on the magnetic recording medium associated with a cue signa Counters 500 and 502 are connected to receive count enabl pulses on line 503 which will cause the counters to chang count state upon eceipt of each pulse. W pulses are applied to the count enable inputs of .the counters from flip-flop 280 (Fig. 9) . When the recorder system is opera in the reverse mode of operation, the PE inputs of the counter will receive an enabling pulse via NAND gates 504BURET., . O^PI and 506 whenever the recording operation is initiated or the cue switch depressed. When this occurs, the P, , P~, P_ , and P. inputs of the counters 500 and 502 will receive a predetermined count of 150 via the lines connected to ground and to the V potential and a count of 150 will be loaded into the counters. The counters will have been enabled into their down-counting mode by the low going F/R signal on a line 508. The counters will now count down to zero as the transducer heads are stepped. When a zero count is reached, the transducer heads will have been stepped through one complete cycle across all of the record¬ ing tracks on the disc. The counter 502 will at this point apply alow-going pulse to its carry output CO which,- through INVERTER 510 and NOR gate 512, will again load a count of 150 into counters 500 and 502. The counting down process will then begin. The counting state of the counters 500 and 502 therefore provides an indication of the position of the transducer heads.Similarly, whέn the recorder system is operating • in the forward mode of operation, the counters will be counted up from zero to 150, the count direction being controlled by the F/R signal on line 508. When the counters 500 and 502 reach a count of 150, all of the inputs to NOR gate 514 will go low. When this occurs, a reset signal will be applied to the counters 500 and 502 via NAND gates '516 and 518, NOR gate 520, and INVERTER 522. The reset pulse will reset the counters to zero and the counters will begin to count upward in synchronism with the W pulses applied to their count enable inputs. Whenever the record operation is initiated or the cue switch dlosed, gates 504 and 506 will load counters 500 and 502 with a count of 150. This will be detected immediately by the NOR gate 514 and the counters will therefore be reset to zero. Thus closing the cue switch or initiating a recording operation results, in effect, in resetting the counters to zero, when the counters are in their forward coun mode. A count detector 524 provides a low-going signal to a line 526 whenever the count state of counters 500 and 502 is greater than 76. It will be appreciated that when the count in counters 500 and 502 is greater than 76, the recorder will have stepped to a point in its recording cycle which is more than half way through the cycle from the point at which the cue switch was closed or recording initiated. It is desirable, therefore, that the recorder operate in the forward direction until the desired cue10 position is reached, since such operation will result in t shortest search time. Similarly, a high signal on line 52 indicates that a count less than 76 is in counters 500 and 502 and that, therefore, the recorder should operate in th reverse direction during the auto search mode of operation15 When the auto search mode is selected, the A signal will go low, clocking the flip-flop 528 such that a high signal will be applied to line 530, indicating that t auto search mode is selected. A flip-flop 532 receives th signal on line 526 which indicates the direction which the20. search is to take. If a forward direction is selected by the decoder 524, the flip-flop 532 will be clocked such th a high signal is applied to line 534. The NAND gate 536 will thus provide a low signal at its output. Similarly, when the reverse direction of search is selected by the25 decoder 524, the flip-flop 532 will provide a high*signal at its Q output to line 538. This will result in a low signal at the output of NAND gate 540. The « signal wi set flip-flop 532 and the >S- signal will reset flip-flop. 532 such that the ASR and ASF signals do not conflict with 0 the <5Ξ - and ._>.>- signals when the manual search of operati is selected.The system will continue to provide the appropriASR and ASF signals until there is a coincidence of the Cl and C2 signal outputs. As seen from a review of Fig. 10, 5 this will occur when the moving cue dot display is coincid with the cue dot display associated with either the initia tion of recording or the occurrence of an event of interes Coincidence of the Cl and C2 signals indicates that the recorder system has been Returned to the appropriate point and this results in resetting the flip-flop 528 via NOR gate 542, thus terminating the auto search operation. The integrated circuits which for a part of the circuitry illustrated in the drawings have all been labeled as to their respective standard integrated circuit part numbers. One source of these integrated circuits is Motorola Semiconductors, Phoenix, Arizona 85036. It should be appreciated that while a recording system adapted specifically for recording and playback of video information in the NTSC format has been disclosed, the* recording system of the present invention may be used with video information in other video formats by simple modifi- cation of the chroma processing circuitry.While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made • therein without departing from the scope of the invention. | 1. In a video recording system incorporating a recording device with limited recording capacity, a console with a monitor to display continuing video information for choice of events to be recorded and played back, and a record control on the console allowing an operator to start and stop the recording device, the improvement comprising a usage circuit synchronized with the recording device to provide a usage signal in video form correspond— ing to the progress of operation of the recording device, said usage circuit having an output to the monitor producing a display of recording device usage on the monitor along with the video information being recorded, a cue control on the console coupled to said usage circuit to produce a cue video signal at the occur¬ rence of a recorded event which.it is anticipated to repla and said usage circuit including a memory continuing the cue video signal as the usage video signal progresses.2. A video recording system as defined in claim.1, wherein the usage signal produces a moving usage dot on- said monitor, and said cue control produces a cue dot in a stationary position along the path of the usage dot..3. A video recording system as defined in claim 2, wherein the usage signal moves the usage dot along the periphery of said monitor.4. A Video recording system as defined in any of claims 1, 2 or 3 wherein the recording device operates in loop fashion to record, upon command, video information for a predetermined time previous to the current video display on the monitor. 5. A yideo recording system as defined in claim 4, including controls on the console to start and stop the recording device, and a memory in said usage circuit providing a continuing video dot corresponding to the usage dot location at the time recording is stopped.6. A video recording system as defined in claim 5, wherein the memory also provides a continuing video dot corresponding to the usage dot location at the time recording is started.7. A video recording system as defined in claim 6, wherein the stationary dot corresponding to start of recording is replaced by the cue video dot upon actuation of the cue control.8. A video recording system as defined in any of claims 1-7, wherein said usage circuit includes storage registers storing location information identifying a plurality of video frame locations within a recording of the program made on said recording device, one of said registers being operative to store- - cue location by actuating the cue control in the record mode, and means for converting the registered location information and the usage signal into a video signal for simultaneous display with the video program. 9. A yideo .recording system as defined in claim 8 wherein another one of said registers operates to store location information corresponding to the usage signal at the time the operator switches off the record mode.10. A video recording system as defined in claim 8, wherein said one register operates to store location information corresponding to the usage signal at the beginning of actuation of the record control.11. A video recording system as defined in claim 10, wherein the cue location is later stored in said one register in place of the begin record information.12. A video recording system as defined in any of claims 1-11, wherein the recording device is a video frame disc recorder including at least one record/playback head and a step controller connected to move said head to record and playback different video frames from different circular tracks, an up-down counter, clock means driving said step controller and said counter means in synchronism, said storage registers being connected to receive location information from said counter, and said converting means receives location information both from said counter and said storage registers.BUR■3 >, ft\' O 13. A video .recording system as defined in claim 12, including a control for operating said clock means in the playback mode at normal, fast, and slower than normal rates to play back the recorded video information at the standard viewing rate or at slower rates variable to stop motion, and to search the recording at higher than normal rate.14. A video recording system as defined in any of claims 8-13, including an auto-search control on the console operating to switch the recording device from record to playback mode and to drive the recording device rapidly to the cue location stored in said one register.15. A system as defined in any of claims 8-13 in which said cue control includes means for storing the output of said one storage register, - means for -providing a vertical signal, means for providing a horizontal signal, means for comparing the outputs of said storing means with said horizontal and vertical signals, and gate means responsive to said comparing means 0 for providing the cue video signal at the appropriate vertical and horizontal'display time. 16. A video recorder and playback system for storing video information consisting of video frames successively presented at a standard frame rate, each of said frames including a first video field of a first field type and.a second video field of a second field type, and for playing back said video information in a desired sequence to produce a video output signal providing either slow motion or normal motion effects when viewed on a monitor, comprising: a frame recorder having a rotatable recording medium, transducer means for recording and playing back video frames in recording tracks on said recording medium, and means for rotating said medium at said standard frame rate and for stepping said transducer means at said standard frame rate such that a video frame may be recorded in each of said recording tracks, means for providing a field reference signal and a playback rate signal, field delay means, responsive to said recorder, for storing a field of video information and providing said stored field at its output, stepping means for stepping said transducer means during playback to recording tracks on said recording medium in accordance with a sequence control signal, switch means for providing said video output signal at its- switch output, said switch means connecting said switch output to said field delay means output or, alternatively, to said recorder in response to a delay field signal, and logic means, responsive to said field reference signal and said playback rate signal, for providing said sequence control signal to said stepping means and for providing said delay field signal to said switch means, whereby video information may be replayed as recorded or in a different sequence from that in which it was recorded, the sequence of fields within the frames of the replayed video information being such that it consists of alternately presented fields of a first field type and a second field type.17. The video recorder and playback system of claim 16, further comprising means for terminating said playback rate signal, whereby the replayed video information will provide a stop action effect when viewed on a monitor.18. The video recorder and playback system of claim 16 for storing video information consisting of alternately presented video frames of a first and a second frame type, each of said frames including a first video field of a first field type and a second video field of a second field type, and for playing back said video information in a desired sequence in response to a playback rate signal, in which said frame recorder includes a rotatable recording medium defining first and second recordingr surfaces, and first and second transducer means for recording and playing back video frames in recording tracks on said first and second recording surfaces of said medium, such that video frames of the first frame type are recorded on said first surface of said medium and video frames of the second type are recorded on said second surface of said medium. 19, The video recorder and playback system of claim 18, further comprising: means for providing a frame reference signal, a chroma inverter connected to said switch output for inverting the-chroma component of a video signal applied thereto in response to a chroma invert signal, means for stepping said first and second transducer means to successive recording tracks on said recording medium in accordance with said sequence control signal, and in which said logic means is responsive to said frame reference signal, said field reference signal, * and said playback rate signal, for providing said sequence control signal to said means for stepping, for providing said delay field signal to said switch means, and for providing said chroma invert signal to said chroma inverter, whereby video information may be replayed in a sequence other than that in which it was recorded on said frame recorder, with the sequence of frames and the sequence of fields within the frames of the replayed video information being such that it consists of alternately presented video frames of first and .second frame types, each of said frames including a first video field of a first field type and a second video field of a second field type.vW TlO 20. The video recorder and playback circuit of claim 19, further comprising means for terminating said playback rate signa,! such that the video information replayed consists of alternately presented frames of said first and second frame types, each of said frames including a first field of a first field type and a second field of a second field type with the video information in the replayed fields being identical, whereby the replayed video information will provide a stop action effect when viewed on a monitor.21. 'The video recorder and playback system of claim 16 or 19, further comprising means for generating said playback rate signal at a rate which is less than the field rate of the video information which is stored, whereby the replayed video information will provide a slow motion effect when viewed on a monitor.22. The video recorder and playback system of claim 16 or 19, further comprising: means for generating a direction indicating signal, and in which said logic means further includes means responsive to said direction indicating signal for altering said sequence control signal such that said transducer means may be stepped to tracks on said medium in a sequence which is reversed from the sequence in which said fields of video information were recorded, whereby the replayed video information will provide a reverse motion effect when viewed on a monitor. | ARVIN IND INC | BOUSSINA T; CROSNO P; HERZOG W; KASPRZAK V; STRATTON B |
WO-1979000215-A1 | 1,979,000,215 | WO | A1 | EN | 19,790,419 | 1,979 | 20,090,507 | new | B07C5 | B65G57 | B07C5, B65G57 | B07C 5/14, B65G 57/18 | METHOD AND APPARATUS FOR SORTING AND STACKING TIMBER | The timber (2) is sorted and stacked automatically with bed laths (15) between the layers of timber in a combined sorting, stacking and lath laying machine in which there are both individual lath laying devices (17-23) outside the sorting partitions (8) under the sorting table and also buffer stores (24) between adjacent partitions (e.g. 8a and 8b), and, to permit automatic laying of laths during the stacking of timber in the partition, the timber (2) that is to be laid off at a given partition (8a), instead of being directly laid in it, is laid in a buffer store (24) between the desired partition (8a) and the preceding partition (8b) in the feed direction of the timber, the timber (16b) being retained in the buffer store while laths are being laid in the desired partition (8a), after which the timber (16b) in fed out over the laid laths (15). | Procedure and machine for sorting and stacking timber The procedure for sorting and stacking sawn timber in sorting partitions arranged under a sorting table or sorting plane is a known one. Insofar as machines for such sorting have been proposed, it has generally been thought sufficient to stack timber for packaging and despatch. It is thus a matter of dried and trimmed timber, the combined sorting and stacking machine thus constituting a final step in the handling process.It may sometimes be desirable, simultaneously with the stacking of the timber in the sorting partitions, also to lay bed laths between the various layers of timber. Such a desire arises, for example, at small sawmills where it is uneconomical to provide sorting, machines both before and after the drying plant. It is- there desired, instead, to trim and sort the newly sawn timber and at the same time stack it for drying in a subsequent dryer. But this necessitates that the timber is first sorted in a sorting machine and then stacked in a lath laying machine or that the laying of laths is done manually. After being dried the timber is passed over a one-piece feeder to a packaging machine.The object of the present invention is to attempt to accomplish sorting in partitions simultaneously with automatic lathing of the timber stacked during sorting. The attempt has been made to make use of the experience gained from stacking of timber in lath laying machines. The chief difficulty experienced in recent times is that, owing to the continuous operation of the machines used in the earlier part of the process, the feed of sawn timber.OMPI ,fa WIPO frj must proceed continuously, whereas, on grounds of time, the automatic feed of bed laths must take place batchwise. It has proved that the time between feeding of two sawn pieces of timber is too short to allow laying of the required number of bed laths between the various layers of timber. By way of exemple a common feed speed is 30 pieces of timber per minute, so that there is only two seconds available for the laying of laths between two layers of timber, which is too short in view of the mass of the lathing and the distance it must be advanced on mechanical grounds.-The present invention is characterized principally in that, outside each sorting partition in a sorting machine, there is arranged a lath laying device which, with the aid of two endless feed chains situated along the sides of the sorting partition, inserts transversely the required number of laths for laying in the partitions of the sor¬ ting machine. ^At the same time, to allow for the operation of the lath laying device also without obstruction of stacking of tim¬ ber that is in progress between adjacent partitions, there is arranged a buffer store for the sawn timber where it can be laid up and retained during the time taken for the lath laying device to lay the required number of laths between one layer of timber and the next.The invention will be apparent from the subsequent claims.Through the invention, accordingly, there is provided a combination machine which, in simplicity and cheapness of price, far surpasses all known sorting and stacking machines. It therefore has its given application, as noted, for small sawmills, where it can be placed before the dryer in order to deliver to it lathed stacks and, after drying of the timber, to be used as sorting and-BΪJRE_ OMPI ?. W1PO packaging machine. Owing to its simplicity and labour- saving proper ties, and very low production cost, however, its use also for large-scale production and in large sawmills has the manifest advantage that a number of parallel-working combination units can be arranged, so that, in the event of a machine fault, there need be no risk of stoppage of the entire production, as is the case at a mill with a single large series of machines or a single large combination machine.The advantage of the invention accordingly is that, when planning new plant or modernizing old plant, the conditions can be created for a flexible and adaptable production flow that is less sensitive to the occurence of machine faults.The invention will now be described with reference to the attached drawings, on whichFig. 1 shows schematically in cross-section an embodi¬ ment of a sorting, stacking and lath laying machine according to the invention, viewed from the side, whileFig. IB shows, also schematically, the same embodiment of the invention viewed from above,Fig. 2 shows a cross-section of a detailed drawing of parts of two adjacent sorting partitions with, between them, a buffer store according to the invention,Fig. 3 shows the same detailed drawing, viewed from above, from which the placing of the feed chains of the lath laying device is more clearly apparent, andFig. 4 shows schematically the lath laying device viewed in cross-section.The embodiment of a sorting, stacking and lath laying machine shown in cross-section in Fig. 1 exhibits a sortingOMPI^SNATlO^ plane or table with endless feed chains 6, each of which passes over turntables at the ends of the sorting .table. As appears from Fig. IB, the embodiment shown is imagined to have four such feed chains. At the feed chains 6 are transversely fastened bars 5 in which are suspended bearing hooks 4 for the timber. The timber 2 is fed in from a one- piece feeder 3 with shorter feed chains onto the central supervisory position 7. From these feed chains the timber 2 passes piece by piece into the bearing hooks 4 when the latter are carried by the lower members of the sorting table feed chains out over the sorting partitions 8 below the sorting plane. The direction of movement is that shown by the lower arrow in Fig. 1. In the various sorting parti¬ tions 8 there are hoists or the like 9 on which the timber will be stacked under stepwise lowering of the hoist plane 10.The sorting table rests on pillars Ig situated between the various partitions, and outside the partitions, as is seen from Fig. lb, there are lath laying devices 20-33 furnished with lath feed chains 17 situated along the sides of the partitions and passing round the pillars 19 between the par¬ titions and over horizontal turntables 18. These lath feed chains 17 have carriers attachments 21 which are brought forward under the ends of lath magazines 22, of which there is one in front of each partition. The attachments 21 are situated opposite one another on opposing feed chains 17 in each partition and, since the feed chains are driven synchronously by means of pinions 18b (Fig. 2) allotted to the partitions, the laths 15 can thus be carried forward over the hoist plane 10 in the partition transversely to the longitudinal direction of the laths 15. The construc¬ tion of the lath feed device is described further on in greater detail in connection with Figs. 3 and 4.Apart from the lath laying devices 20-23 outside the various partitions, the invention provides also between adjacent partitions 8, e.g. partitions 8a and 8b (Figs. 2 and 3) , buffer stores 24 for the sawn timber 2 to allow for the operation of the various lath laying devices 20-23 without obstruction of the ongoing timber stacking in the partition, e.g. 8a, to which a given buffer store 24 is alotted.The various buffer stores 24 are in each particular case situated between the partition concerned, e.g. 8a, and a partition (e.g. 8b) in .front of it viewed in the direction of the timber feed (lower arrow in Fig. 1) . Instead of depositing the timber from the feed conveyor 6 and the hooks.4 directly on the hoist plane 10 in the desired par- tition, e.g. 8a, however, the pieces of timber 2 are laid in the buffer store 24 in front of the desired partition 8a and adjoining the front edge of the buffer store 24, i.e. the edge adjoining the partition 8b ahead-of it, as marked by 16b in 'Fig. 2, while the lath laying device passes laths 15 out over the hoist plane 10 into the desired partition 8a.As appears from Fig. 2, there is on the bars 5, in which the bearing hooks 4 are suspended in the four feed chains 6 side by side, an attachment 26 (one for each hook) on a common shaft 26a perpendicular to these chains 6, the attachments being furnished with a spring-loaded catch designed to engage in the edge of the deposited pieces of timber 16b and carry them forward into buffer store 24 in the direction towards the desired partition 8a until they bear against a stop 27 which is in operating position while laying of laths is proceeding in the partition. As soon as the laying of laths has been completed, the stop 27 is released and layers of timber laid in the buffer store are drawn in over the laths 15 laid in partition 8a. If, as shown in Fig. 2, stacking is in progress also in the preceding partition 8b and if a layer of timber 16 is on a level with the buffer store of partition 8a, this does not prevent movement of the attachment 26, as its end is spring-loaded and the layer of timber is stopped' by store 24. On the other hand the stop 27 has at that time been released, so that the layer of timber 16b can- be pushed out over hoist plane 10 of the sorting partition 8a.The stops 25, of which there is one for each of the hooks 4 of the four feed chains 6, are brought up into stop posi¬ tion -.under, for example, electric or hydraulic drive from the central supervisory position 7 in conjunction with classification of the various pieces of timber. As soon as the stops 25 have pushed off the piece of timber 16a, des-- tined for the desired sorting partition, e.g. 8a, from hook 4, the stops 25 are lowered again to unoperational position, as shown in Fig. 3, so that the laid-off piece of timber 16a can be brought by attachment 26 up against stop 27 on the buffer store 24.There are at least two stops 27 along the length of the buffer store 24. These stops 27 are also assumed to be mounted in round bars below the level of the buffer store 24, by means of which the stops 27 can be turned down side¬ ways to unoperational position.' This is assumed to be done with an electrically controlled hydraulic device, not shown in the drawing, which comes into operation as soon as the last piece of timber 16 has been brought down onto the hoist plane 10, as the piece of timber 16 then actuates an electric contact, also not shown on the drawing. -The elec¬ tric contact also serves to start the lath laying device 20-23 so that laths 15 are carried out over the hoist plane 10 or an already laid layer of timber 16 by means of the lath feed chains 17. When the last lath 15 has passed out from the lath magazine 22 and reached its intended position it actuates an electric contact, not shown in Fig. 2, which under the action of said hydraulic device, returns the stop 27 to operational position. When the last lath actuates the electric contact, the drive for the lath laying device BU EAOMPI 20-23 is also stopped.The construction of the lath laying device will be seen from Figs, lb, 2, 3 and 4. In front of each partition 8 there is a lath magazine 22 and, associated with each lath magazine, there are two screw feeders 22a (Figs. 3 and 4) , to which laths 15 are fed from a lath magazine 15a common to the entire sorting machine. The screw feeders 22a con¬ tinuously fill up the various lath magazines 22 with laths 15. As earlier noted, there is on each side of every par¬ tition 8 a lath feed chain 17 the feeding part of which is on the inner side of the partition, e.g. 8a, while the return- art passes back over turntable 18 on the rear side of the pillars 19. Both parts slide preferentially on one or more stay plates 20, the stay plate 20 under the feeding part having either hatches 23 at the points where the lath is to be brought down to the hoist plane or earlier laid timber plane, or folding hatches 23a. It is also conceiv¬ able to arrange solely folding supports at the aforesaid depositing points. As appears especially from Figs. 3 and 4, the lath feed chains 17 have attachments 21 which, when the feeding parts -of the feed chains 17 pass under the lath magazine 22, take up the ends of the lowermost lath 15 and move it out, transversely to its longitudinal direktion over the hoist plane 10 in the stacking partition. •By, in this way, alternatively laying out laths 15 and pieces of timber 16b over the hoist plane 10 and stepwise lowering this plane, the timber can be gradually stacked so that, in sorting partition 8a, one obtains a stack 13 as partly shown in partition 8b. When the hoist plane 10, which in partition 8a is shown in the form of- a roll 10, which can be raised and lowered by means of a' vertical hoist device 9 actuated by a screw, has been brought down to its lowest position, the stack in partition 8a has also been completed.ijυREA r-0MP1 _S^ ATlCg> In partition 8b the hoist plane is shown in the form of an endless chain 12 carried by a beam, the chain being raisable and lowerable by means of a hoist device '9 in the form of a nut which can be moved up and down by a vertical screw. A hoist plane of this kind is suitable when it is desired to feed out the final stacks in the longitudinal direction of the sorting machine in order to obtain a num¬ ber of stacks 13a outside the end of the machine, as shown in Figs. 1 and lb. Alternatively the stacks of timber 13 can be brought out sideways if the hoist plane is made in the form of endless chains moving perpendicular to the direction of movement of the timber feed chains 6. The stacks of timber 13b fed out at the side of the sorting machine can then obtain positions as shown in Fig. lb.The drive for the lath feed chains 17 is shown in Figs. 3 and 4. With a pinion 18b one of the leading wheels 18 can be driven over a gear-wheel 18a, so driving each of the chains 17 along the side of each partition 8.When the laths 15 have been brought by the attachments 21 up to the positions shown in Fig. 3, hatches 23a under the ends, of the laths can be lowered. By means of a link sys¬ tem 23b it can also be ensured that this takes place simul taneously.Although the invention has been described with reference t one of its embodiments, it can nevertheless be arbitrarily varied within the scope of the following claims.-BΪTREA_ OMPI . W1P0 | C L A I S1. Procedure for sorting and stacking from a sorting plane in a sorting and stacking machine sawn timber with bed laths between each two layers of timber in a number of sorting partitions situated under the plane, the tim¬ ber (2) , after passing a central supervisory position (7) and there being classified (possibly by individual electric marking) according to class, dimension, grade or the like for sorting into a given partition, being transported hori¬ zontally, transversely to the feed direction in said plane, out over the sorting partitions (9) and, consequent on said individual classification, being laid off adjacent to the desired partition, characterized in that the timber (2) , in order to allow for automatic laying of laths during' the stacking in the partition (8) , is laid off in a buffer store (24) situated between the desired partition (8a) and the preceding- partition (8b) in the direction of feed of the timber, the timber (16a) being retained in the buffer store while laths are being laid in the sorting partition (8a) , thereafter being directly fed out over the laid laths (15) .2. Procedure according to claim 1, characterized in that the pieces of timber (2) from the buffer store (24) are carried out by timber carriers attachments (26) , driven by- timber feed chains (6) , sideways over a hoist or the like(9) in the desired partition (8a) until a layer of timber (16) has been formed, whereupon, during continued laying off of sorted pieces of timber (2) in the buffer store (24) the laths (15) are carried out into position over the al¬ ready laid layer of timber (16) , possibly lowered with the hoist plane (9) , and finally the pieces of timber (16b) laid and retained in the buffer store (24) during the lay¬ ing of laths are thereafter carried by the attachments (26) possibly one by one, out over the laid laths (15) to form aOMPI . -- W W11PP00 l^ new layer of timber, which is then lowered to make space for -renewed laying of laths and formation of the next layer of timber (16) as described above.3. Procedure according to claim 1 or 2, characterized in that the pieces of timber (2, 16b) are laid off in the buffer store (24) adjoining the edge furthest from the de¬ sired partition (8a) and are gradually brought by the attachments (26) up against a stop (27) , operative during laying of laths, at an. edge adjoining the desired partition (8a).4. Procedure according to claim 1, 2 or 3, characterized in that the pieces of timber (2) , during their transport in the sorting plane, are transported in the known manner in hooks (4)- suspended in timber feed chains (6) , from which hooks the pieces of timber are laid down in the buffer store (24) allotted to the partition (8a) selected through the individual marking.5. Sorting and stacking machine for implementation of the procedure according to one or more of claims 1-4, contai¬ ning a sorting plane in which.the pieces of timber (2) are fed piece by piece, transversely to the direction of move¬ ment of timber feed chains (6) situated in the sorting plane, for sorting and stacking in a number of sorting par¬ titions (8) placed under the sorting plane, and a central supervisory position (7) for individual classification (e.g. electrically) of the pieces of timber (2) according to class, dimension, grade or the like, characterized in that the partitions (8) of the machine, in order to allow for laying of laths during stacking in a particular machine* partition ( 8a) , apart from having a vertically adjustable hoist plane (10) in the known manner, also have a buffer store ( 24 ) for the sorted pieces of timber ( 16a) destined to the desired partition ( 8a) , the buffer store lying bet¬ ween the desired partition ( 8a) and the preceding partition ( 8b)-BUREAOMPI fa 1P04 l in the direction of feed of the timber, in the which store (24) the pieces of timber (2, 16a) are brought to bear against a stop (27) so as to be retained in the. store (24) while laths are being laid over the hoist plane by a lath laying device associated with each partition to prepare for the reception of a layer of timber (16) .6. Sorting and stacking machine according to claim 5, char¬ acterized in that, after laying of laths, the pieces of timber (16b) collected in the buffer store (24) are moved out by lath feed chains (17) with lath attachments (21) in the lath laying device (17-23) , after release of the stop (27) , sideways over the laths (15) laid out in the hoist plane (10) .7. Sorting and stacking machine according to claim 5 or 6, characterized in that the timber feed device (4, 6) of the sorting plane is so arranged or controlled in relation to the buffer store (24) that the pieces of timber (2) are laid off in the buffer store (24) , first adjoining its edge furthest from the desired partition (8a) , and are gradually brought by the attachments (26) up to the stop (27) , which is operational during the laying of laths, at the edge adjoining the desired partition (8a) .8. Sorting and stacking machine according to claims 4-7, characterized in that the feed chains (6) of the sorting plane are provided with hanging hooks (4) on which the timber (2) is transported from the supervisory position (7) and laid down in the buffer store (24) allotted to the par¬ tition (8a) selected through the individual marking, e.g. by controlled removal of the pieces of timber (2) by means of a stop (25) from the respective hooks (4) .9. Sorting and stacking machine according to claims 4-8, characterized in that, on release of the stop. (27) , the pieces of timber (16a) laid in the buffer store (24) are fed forward to the hoist olane (9) of the desired sor irrøTF .OMPI 12partition (8a) by timber attachments (26) , preferably elastic, placed on the timber feed chains (6) .10. Sorting and stacking machine according to claim 9, . characterized in that corresponding timber attachments(26) on mutually parallel timber feed chains are placed o a common shaft (26a) so as to feed the pieces of timber(16a) forward in parallel with one another.11. Sorting and-stacking machine according to claims 4-10, characterized in that the lath laying device (17-23) driv forward the laths (15) with suitable distribution, trans¬ versely to their longitudinal direction and with the ends resting in lath attachments (21) on the feed members (17) out over the hoist plane by means of two endless chains (17) moving synchronously with one another, the feed mem¬ bers of which, essentially on a level with the buffer sto (24) , run horizontally along the sides of each sorting partition (8) .12. Sorting and' stacking machine according to claim 10, characterized in that the lath attachments (21) interact with hatches (23) or retracting 'means (23a) , one or more, through which the ends of the laths (15) can be released for vertical movement downwards.13. Sorting and stacking machine according to claim 12, characterized in that the lath feed chains (17) interact with their lath magazines (22) situated outside the sorti partitions (8) , in the which magazines the laths (15) are placed in a vertical stack one on the other, the lath ' attachments (21) of the feed chains (17) , on passage unde the ends of the magazine (22) , being able through contino lowering of laths (15) , to take up the lowermost lath (15 in order to move it out over the hoist plane (10) . .14. Sorting and stacking machine according to claims 10- characterized in that the stop (27) of the buffer store is automatically released as soon as the last piece of timber in a layer (16) has been laid in position and is reactiva¬ ted when the last lath attachments (21) on the lath chains (17) have left the lath store and all laths (15) have come into position. | WICKMAN E | WICKMAN E |
WO-1979000225-A1 | 1,979,000,225 | WO | A1 | XX | 19,790,503 | 1,979 | 20,090,507 | new | F24J3 | null | F24J2, F24J3 | F24J 2/20E, F24J 2/24D | INFLATED FLEXIBLE SOLAR COLLECTORS | An inflatable collector for solar energy is provided in which superposed layers of plastic sheet material (18, 19) a heat sealed to one another to provide a pair of layers providing an absorber unit in which the upper layer (19) is pigmented to absorb solar radiation and the pair of layers are sealed to one another in a pattern providing a continuous elongated path. Fluid is supplied to one end of this elongated path and at least one transparent layer (25) is provided overlying the pair of layers, to provide a return space (21) above the pair of layers, and valve means (22) are provided to interconnect the end of the elongated path remote from the fluid supply end with the return space so that fluid heated in the elongated path is further heated in the return space before being withdrawn from the collector. | INFLATED FLEXIBLE SOLΛR COLLECTORS DESCRIPTION Technical FieldThe present invention relates to inflated flexible solar collectors. Background ArtThe need for low cost, durable and efficient collectors for solar energy to enable the heating of homes, factories and swimming pools is well known, and this is the objective of this invention. Disclosure of InventionIn accordance with this invention, an inflatable collector for solar energy is provided in which super¬ posed layers of plastic sheet material are heat sealed, taped or glued to one another to preferably provide at least one lower layer of static air for insulating the underside of the collector, a pair of layers above the lower layer providing an absorber unit, the upper of said pair of layers being pigmented to absorb solar radiation and the pair of layers being sealed to one another in a pattern providing a continuous elongated path through the absorber unit. Fluid is supplied into one end of the elongated path and at least one layer of transparent sheet material overlies the absorber unit to provide a return space above the pair of layers, and means interconnect the end of the elongated path remote from the supply end with the return space so that fluid heated in the elongated path is further heated in the return space before being withdrawn therefrom.A feature of the invention is the double pass of the fluid being heated with respect to the upper layer of the heat absorber unit which provides the heat absorbing surface. This double pass increases the temperature of the fluid which is removed from a collector of given size and flow capacity. It is also important to insulate the collector from the air and from the underlying support. For this purpose,OMPI' pairs of layers are used both above and below the absorber unit, and these are inflated with static air.Another feature of the invention is the employment of a pair of inflated transparent layers which are sealed together in parallel lines to form ribs which insulate the hot fluid return while it simultaneously provides improved resistance to wind damage and improved absorption of solar energ .The above features of this invention may be used alone or preferably in combination with one another. Other and further features of the invention will be apparent from the following description of the drawings. Brief Description of DrawingsFIG. 1 is a perspective view with portions cut away showing an illustrative inflatable collector for solar energy constructed in accordance with the invention;FIG. 2 is a cross-section taken at the line 2-2 of FIG. 1 to further show the disposition of the layers;FIG. 3 is a cross-section taken on the line 3-3 of FIG. 1 showing the inlet and outlet structures and the check valves used to inflate the overlying layers and the lower layers which insulate the collector;FIG. 4 is a sectional view diagraramatically illus¬ trating an alternate form of the invention of simplified cons ruction; andFIG. 5 is another cross-section on the line 3-3 of FIG. 1 showing preferred construction at the air inlet and outlet zone.Referring more particularly to FIG. 1, the numeral 10 identifies an inflatable solar energy collector formed by a plurality of flexible plastic layers which are sealed together at their peripheries 11 to form a mattress-type structure. The periphery 11 is preferably reinforced with a wire, rope or semi-ridged plastic pipe 12 and portions of the sealed periphery are notched out at 13 to enable the collector 10 to be tied down with ropes, rubber binders or stakes. Referring first to the lowermost layers 14 and 15, these are inflated thru check valve 30 when the fluid being heated is air (see FIG. 3) and optionally given structural stability by securements 17. The layers 14 and 15 are normally constituted by black-pigmented thermoplastic, and they serve, especially when inflated, to insulate the underside of the collector.Above the insulating layers 14 and 15 are layers 18 and 19 which together provide an absorber unit. Layer 19, and optionally also layer 18, is pigmented, preferably with solar selective coatings or pigments, to absorb solar energy. Layers 18 and 19 are sealed in a pattern which forms a continuous elongated path 29 which may be termed a serpentine path. Layer 19 is formed with small slits 20, which allow fluid to pass through and agitate the contents in the return space 21 which overlies the layer 19. Valve means 22 allow the fluid between layers 18 and 19 to pass through layer 19 at the remote end of path 29 and enter return space 21 below layer 25. The fluid in the return space 21 is further heated and removed through outlet 23, which is positioned near the cool air inlet 24. The fluid in the structure shown in FIG. 1 is preferably air, but water can be used, especially when the underlayers are not inflated. The overlying layers 25 and 26 are of clear plastic material to allow solar energy to pass through and reach the pigmented layer 19. On the other hand, infra-red radiation emitted by layer 19 is reflected by the layers 25 and 26, and these layers may be treated to maximize reflection of infra-red radiation in order to keep it from escaping from the collector. The layers 25 and 26 are sealed together in parallel lines to provide ribs 27 and these layers are inflated with some of the cold air enter¬ ing at 24 via check valve 30. Ribs 27 provide structural stability and also serve to enhance absorption of solar radiation. This occurs because solar radiation which strikes the ribs at an angle can be reflected off the surface of a rib remote from the radiation into the near surface of the adjacent rib. The radiation striking the near surface of any rib hits it at a steeper angle and penetrates the layer 26 more easily. A relief valve 28 may be used to deflate the overlying layers 25 and 26, and a similar relief valve can be used to deflate the lowermost layers 14 and 15. The inflated layers 14 and 15 and 25 and 26 remain inflated when the fan blowing air through air inlet 24 is shut off, so the unit retains its strength and wind resistance when not in operation. The plastic layers are preferably .006 inch or thicker for mechanical integrity.Referring more particularly to FIG. 2, a portion of the solar energy collector 10 is shown in cross-section to better show the air agitators 20 and the valve means 22 which allow the contents of the absorber unit to pass from between layers 18 and 19 to the return space 21 be¬ tween layers 19 and 25. This cross-section also shows how layers 14 and 15 join together to form an inflated insulative underlayer which can be parallel or spot secured as shown at 17 to add rigidity to the collector.Referring more particularly to FIG. 3, cold air enters the collector via a venturi tube 24 which is the sole source of air in the collector 10. This air under pressure causes inflation of the paired upper layers 25 and 26, and the paired underlayers 14 and 15. This is achieved by connections containing check valves which extend from tube 24 through layers 25 and 15 as shown. This connection and check valve assembly is identified by numeral 30. Cold air indicated by arrow 31 passes below pigmented layer 19 and above optionally pigmented layer 18 and the contact with heated layer 19 heats the air. Agitator slits 20 allow small amounts of heated air held between layers 18 and 19 to bleed into the return space 21 and agitate the air in the return space, this air moving as shown by arrow 32 toward the hot air outlet 23.In the preferred structure shown in FIG. 5, the air inlet and air outlet are shown in phantom, and the pressure of the air near the inlet opens flap valves 40 and 41 which cover aligned openings 42 and 43, respectively, to inflate the upper and lower units of the solar mattress.The layers surrounding the openings 42 and 43 are heat sealed to one another as indicated at 44, so that static air is confined where it is desired. FIG. 5 also shows a grommet 45 used to seal the margin 46 of the mattress via protective U-shaped marginal area 47.FIG. 4 shows an optional embodiment of the invention which is characterized by a simplified construction. In this form of the invention, only a single overlying layer 26 is used, and cold air inlet 24 inflates the insulating area 36 between the transparent layer 25 and the overlying layer 26. The action is the same as shown in the previous figures in that some air entering the absorber unit between layers 18 and 19 via tube 24 inflates the insulating area 36 by means of a tube and check valve assembly 30. The air is heated in the absorber unit where it follows a serpentine path indicated by arrow 34 and finally reaches valve means 22 at the end of the path. The partially heated air rises through the valve means 22 into the return air space 21 where it is further heated and agitated by undulations 33 in layer 19. The return air follows a return serpentine path 37 back to the hot air outlet 23. In this simplified construction, the four layers 26, 25, 19 and 18 are sealed at their peripheries 11 which is reinforced by wire, ropes or tubing 12. The underlying layers are omitted in this simplified construction. When a liquid, such as water, is heated, the insulating area 36 is separately inflated with air. Best Mode for Carrying Out the Invention The solar collector may include thermostats for operating the air supply fan only when the sun is shining,ty wipo and other operational features may be added for special purpose. The plastic materials used may be of any type such as polyethylene, Mylar, Tedlar or any suitable flex¬ ible, sealable plastic. The dimensions may be any shape or configuration, but generally rectangular is best. | WHAT IS CLAIMED IS:1. An inflatable collector for solar energy comprising superposed layers of plastic sheet material which are secured to one another to provide at least one lower layer for insulating the underside of the collector, a pair of layers above...said lower layer providing an absorber unit, the upper of said pair of layers being pigmented to absorb solar radiation and said pair of layers being sealed to one another in a pattern providing a continuous elongated path through said absorber unit, means for supplying a fluid into one end of said elongated path, at least one layer overlying said absorber unit, said overlying layer being transparent and providing a return space above said pair of layers, and valve means interconnecting the end of said elongated path remote from the supply end with said return space whereby fluid heated in said elongated path is further heated in said return space, and means for withdrawing heated fluid from said return space. 2. An inflatable solar collector as recited in claim 1 in which said fluid is air.3. An inflatable solar collector as recited in claim 1 or 2 in which a pair of lower layers is used to insulate the underside of the collector, said lower layers being sealed to one another and inflated with air.4. An inflatable solar collector as recited in claim 1 or 2 in which a pair of transparent layers overlie said absorber unit, said transparent layers being sealed to one another and inflated with air. 5. An inflatable solar collector as recited in claim 4 in which said transparent layers are sealed to one another in parallel spaced apart lines to form a series of inflated ribs. 6. An inflatable solar collector as recited in claim 2 in which said pigmented layer is slit to provide vents along the length of said elongated path to agitate the air in said return space. 7. An inflatable solar collector as recited in claim 2 or 6 in which a pair of lower layers is used to insulate the underside of the collector and a pair of transparent layers overlie said absorber unit, each of said lower layers and said transparent layers being sealed to one another and inflated with air.8. An inflatable solar collector as recited in claim 7 in which the means for supplying air to said elongated path includes means comprising a check valve for maintaining the inflation of said lower layers and said transparent layers.9. An inflatable solar collector as recited in any of claims 1, 2 or 6 in which said elongated path is pro¬ vided by parallel seal lines which form a serpentine path.10. An inflatable solar collector as recited in claim 9 in which said pigmented layer is also sealed to said overlying transparent layer to provide a return space.11. An inflatable solar collector as recited in claim 1 or 2 in which said heat sealed layers provide tie down areas at the margins thereof. 12. An inflatable solar collector as recited in any of claims 1, 2 or 6 in which the heated fluid is withdrawn from said return space at a point close to the fluid supply means.13. An inflatable solar collector as recited in any of claims 1, 2 or 6 in which said superposed layers of plastic sheet material are heat sealed to one another.-B , \ f | CROMBIE L; CROMBIE T | CROMBIE L; CROMBIE T |
WO-1979000229-A1 | 1,979,000,229 | WO | A1 | EN | 19,790,503 | 1,979 | 20,090,507 | new | H01M10 | H01M6 | H01M6, H01M10 | H01M 10/04D, H01M 6/48, T01M 6/48 | ELECTRIC STORAGE BATTERIES | A multicell spirally wound electric storage battery, preferably of lead-acid type is provided in which the cells are coaxial and are divided from each other by partitions disposed transverse to the said axis and the cells are interconnected by portions of the plates which pass through the said partitions. A method of making the battery is also disclosed which involves winding the battery from strips of electrode and forming the partitions from hot melt adhesive during the winding process. | . 1.ELECTRIC STORAGE BATTERIESTECHNICAL FIELDThe present invention relates to electric storage batteries and provides a novel multicell structure as well as a novel form of intercell separation and 5. interconnection of plates between different cells. BACKGROUND ARTSpirally wound single cells are known, see for example British Patent Specification No. 1531225.The present invention has as an object the 10. provision of a multicell spirally wound lead acid battery.Whilst developed particularly for so called sealed cell applications for the lead acid electro¬ chemical system it is applicable also to flooded cell 15. systems and is not excluded from applicability to other electrochemical couples such as alkaline systems e.g.using nickel cadmium active materials. DISCLOSURE OF THE INVENTIONAccording to the present invention there is 20. provided a multicell spirally wound electric storage battery in which the cells are coaxial and are divided from each other by partitions disposed transverse to the said . axis and the cells are interconnected by portions of the plates which pass through the said 25. partitions.In a preferred form of the invention the cells are of annular form and are arranged around a central former. The battery may further include a seal between each partition and the former, outer container 30. means enclosing the outer circumference of the annularO PI . 2.cells, a seal being provided between the said outer container means and the outer peripheral edge of each partition.The battery may further include a seal between5. each partition and the former, outer container means enclosing the outer circumference of the annular cells, a seal being provided between the said outer container means and the outer peripheral edge of each partition. In a preferred embodiment electrolyte10. access and venting means are provided in the former for each cell.Each current conducting element in one cell is preferably integral with a current conducting element of opposite polarity in an adjacent cell.15. The plates may comprise current conducting elements of expanded metal and preferably the majority of the mesh elements extend transverse to the length of the strip so as to shorten the current pathways between adjacent cells.20. The portion of the plates which extends through the partition is preferably apertured and the apertures are filled with the material of the partitions.In this form of the invention each plate has a pair of active material carrying portions extending along25. its length with an intercell connector portion located therebetween, the intercell connector portions having a greater cross sectional area of metal per unit length than the active material carrying portions.A preferred form of the invention provides a30. battery with two or more cells in which each cellOMPI comprises first and second layers of conducting mesh carrying active material, separated by a separator, the cells being disposed edge to edge with an intercell connector between one layer of each cell,5. provided by a gap part of the mesh not carrying active material, and integral with the layers on either side of it carrying active material, and each constituting a plate of a respective cell.The electrolyte impervious partition between10. adjacent cells can pass through the intercell connector in the perforations in the mesh not carrying the active material.Preferably each cell is in the form of a coil with the first and second layers constituting the cell plates15. being annular, or part annular and concentric with each other. The cells are disposed side by side along the axis of the coil with the plates of adjacent cells disposed edge to edge with one another.The invention also extends to a novel method of20. making a battery in accordance with the invention which comprises providing a number of longitudinally extending electrode affording members with a positive active material strip along one side and a negative active material strip along the other side, direct electrical25. interconnection being provided between the strips of opposite polarity along the full length of the electrode member, either continuously or discontinuously, a partition region free of active material being disposed between the two active material strips, and providing30. one positive terminal strip having a continuous currentfjU E cT OMPΪ take off band along one edge and a negative active material strip electrically connected thereto along the other edge, a partition region free of active material being disposed between the take off band and the active5. material strip, and one negative terminal strip having a continuous current take off band along one edge and a positive active material strip electrically -connected thereto along the other edge, a partition region free of active material being disposed between the take off10. band and the active material strip, overlapping positive active material strips with negative active material strips, with interleaved separator material and covering the free face of at least all the negative strips or at least all the positive strips with separator material,15. presenting one end of the overlapped strips to the surface of a former and winding the assembly around the former into a pack, with separator material between contacting faces of active material, the partition region being supplied with partition polymer material20. compatible with the material of the former and effective to produce an electrolyte impervious seal therewith, the partition polymer material being supplied in such condition and or shape as to form a continuous electrolyte impervious seal with its own juxtaposed 25. surface between each turn of the spirally wound pack whereby an annular electrolyte impervious partition between adjacent cells is formed in the fully wound cell, the partition polymer material being supplied to the partition region either before the assembly30. is wound round the former, or whilst it is being wound round the former and providing an outer . 5 ,container forming a electrolyte impervious seal with the outer peripheral edge of each partition between the cells.Thus, in one form of the method, the partition 5. region is provided continuously with hot melt adhesive in a hot adhesive state immediately prior to the moment when the portion of the region which is being supplied with hot melt adhesive is pressed against the outer surface of the hot melt adhesive in 10. the barrier region previously supplied and already wound. The former is preferably provided with electrolyte access and venting means disposed opposite each cell. The access and venting means may be a single hole 15. for each cell which is occluded by a resilient lining tube.Alternatively separate electrolyte access and venting means may be provided for each cell.20. BEST MODE OF CARRYING OUT THE INVENTION The invention may be put into practice in various ways and a number of specific embodiments will be described to illustrate the invention with reference to the accompanying drawings in which: 5. Figure 1 is a perspective view of an individual grid element; Figure 2 is a cross-section of an array of two terminal grids and two intermediate grid elements prior to winding; 10. Figure 3 is- a perspective view of the arrangement shown in Figure 2 showing the central perforated • former around which the element assembly is wound, Figure - is a view in the same sense on a reduced scaie showing the finally wound construction 15. wrapped in εn encapsulating plastic εheeτ;; Figure 5 is a longitudinal cross section of a former for use in the invention and shows a flexible liner which provides the seal for the vents to * individual cells; 20. Figure 6 is a cross section of the wound path showing a stepped former; Figure 7 shows an alternative arrangement of stepped former;Figure 8 shows in diagrammatic cross section 25. a modified form of sealing arrangement between cells in which the intercell conductor is provided with a channel section in which the sealant is located;Figure 9 is an enlarged cross section to scale of the arrangement shown in Figure 2; 30. Figure 10 is a vertical cross section of a fullyfsUREΛc _O PI wound and encased battery in accordance with the invention; andFigure 11 is a diagrammatic longitudinal section of apparatus for carrying out the winding of the battery. 8.Referring now to Figure 1 , the grid strip comprises a perforated strip grid,preferably a slit expanded mesh grid, having a plastic member 20 extending down its length along its centre, this 5. being the basic form of the grid element referred to as an intermediate grid element above. Terminal elements are similar except that one half of the expanded mesh is replaced by a longitudinal selvedge of solid metal to which the current take-off 10. tabs or members are connected. The end element thus has a central continuous plastic member 20 which will eventually constitute the cell partition.The positive half of the expanded grid strip is labell21 and the negative half of the expanded grid strip 22. 15. It should be noted the expanded grid strip 21,22 extends right through the partition element 20 providing continuous electrical inter-connection between the positive and negative elements of each grid element and thus minimising intercell connector20. resistance. Referring again to Figure 2, the multi¬ element assembly is made up by overlapping the positive strip 21 of one individual grid element with the negative strip 22 of another individual grid element, the elements having their members 20 running25. parallel to each other. A separator 25 is placed between the juxtaposed positive and negative elements and separator material is also provided on one or other of the back or front faces of the whole assembly so that when wound the elements are also 30. separated from other in the wound assembly. In the'BUREA_OMPI Figure 2, arrangement this is done by providing an envelope of separator material around each of the negative elements 22. This envelope extends up to the edge of each member 20 and if desired can either 5. be left open at its ends or sealed at its ends by an appropriate adhesive, or in the case of a thermoplastic separator element, by welding. If the separator material is thermoplastic then it may also extend across the intercell elements 20 and10. be sealed to it so as not to interfere with the integrity of the intercell seal. Clearly the polymer used in the separator must be compatible with that used in the member 20 so that an effective seal is formed. There may be some15- advantages also in enveloping the positive plate so that in arrangements where the plates are orientated in the battery in use in a vertical plane the bottom of the envelope around the positive will act to retain any active material shed from the'20. positive and thus minimise bridging of the plates in the individual cells. Referring now to Figure 3, the assembly shown in Figure 2 is shown in position prior to winding around a central former 30. This is made of a tube of a resin compatible with and25. effective to form a seal with the resin of the member 20. For example the members 20 may be a polyolefin e.g. a polyethylene based hot melt composition and then the tube 30 will be made of a compatible polyolefin based composition. The tube 30 is provided30. with holes 31 extending through its wall and positioned-βU EΛ TOMPI 10 .so as to be juxi-aposeα to the overlapped grid elements 21 and 22. Grid elements 21 and 22 are preferably- perforated prior to assembly into the configuration shown in Figure 2 and the perforations 42 are spaced from the5. end at which the winding has started in such a way as to be essentially juxtaposed to each other although exact overlap is not needed. Logarithmic spacing of the holes would therefore -be appropriate. Clearly the separator must not be punched since otherwise treeing10. through between the positive and negative plate could very readilj- occur.The punching of the grid strips is done after pasting. These holes 42 provide a duct 43 through which electrolyte entering the cell through the holes 31 in15. the former 30 can more readily gain access to the intεrio: of each cell. The tube jp is preferably provided with a step as shown in the cross-section in Figure 5 since this assists in the location of the multi-element assembly shown in Figure 2 at the beginning of the20. winding operation. Indeed it night be that a #slit would be formed or a notch formed in the former 30 so as to positively grip the ends of the multi-element assembly and further assist automatic winding of the array. Figure 6 identifies the step by the reference25. ^-0. .An alternative stepped arrangement is shown in Figure 7 in which the thickness cf the tube is built up on its external diameter so that its internal profile is circular. This is of advantage in connection with the sealing arrangement which is30. shown in Figure 5 and can conveniently be used to provide a sealed form of battery using this inventive concept. The arrangement shown in Figure , Figure 5 and Figure 7 can have its electrolyte 1 1 .content added to it after winding and this permits dry winding which is advantageous from the point of view of retaining the strength of the separator material and ease of handling. The electrolyte 5. may be added to the battery by injecting a measured quantity of electrolyte into the central tube 32 of the former 30 and then either allowing the electrolyte to percolate outwardly or preferably rotating the assembly around the longitudinal axis10. of the tube 30 so as to force the electrolyte out under centrifugal force into the individual cells. After this measured volume of electrolyte has been taken up, or if preferred after decanting any surplus not absorbed by the assembly, the central15. tube 32 of the tube 30 can have a close fitting rubber sleeve 35 pushed into place and this will then act as a pressure release valve during any gassing which may occur during high overcharge conditions during use of the cell but at the same20. time will prevent electrolyte leakage of any substantial extent between the individual cells. In an alternative arrangement the assembly is wound with the paste wet.It should be explained that a variety of tech-25. niques are available with regard to the sequence of operations in making up and wάnάing the cell elements. One possibility is to paste the strips leaving an open region between the positive and negative strips, then apply the hot melt adhesive to30. the strip between the positive and negative pastesOMPI• ■■ WIPO and then wind the assembly with the paste wet. Another alternative is to dry the paste prior to applying*the hot melt adhesive. A further alternative is that instead of hot melt adhesive one could 5. use some other form of activatable resin composition capable of forming a seal with the resin of the tube 30. It should be appreciated that the portion of the mesh between the positive and negative paste strips will be fully inter-penetrated by the members 20 so10. as to form an effective seal between the positive and negative halves of the individual cell element.In a further alternative the region around which the member 20 is formed could be an unperforated, unexpended strip extending down the centre of the the15. mesh element. Two other possibilities for forming the member 20 are to form a basic strip of polymer whic may or may not be sealable to the polymer of the element 30 down the central portion of the element before pasting, achieve the pasting and20. then clean the surface of the member 20 ready for attachment to the tube 30. An alternative to this possibility is to apply a masking film e.g. a masking tape or some polymer film which will adhere to the polymer of the member 20 in this form, paste25. the element, remove the masking film and then achieve the sealing. A further modification to this alternative is to apply a bead of hot melt adhesive or other resin of improved compatability and sealing properties with the polymer of the member 30 after30. pasting has been carried out. Figure 9 shows a cross-O PI 13.section to scale of the arrangements shown schematically in Figure 2. The members 20 here are shown as being formed either of hot melt adhesive or of epoxy resin. The structure when using hot melt adhesive utilises 5. its good sealing properties with lead when held under compression. In a further arrangement shown in Figure 8 the sealing of successive turns of members 20 is facilitated by the forming of the conductor in the region of the member 20 with a V or other duct10. section and filling this section with the hot melt ad esive immediately prior to the moment of the members 20 being juxtaposed to each other so that the resin in one duct is pressed into the back of the preceding duct. Apparatus appropriate for carrying15. out this aspect of the invention will be described below.Figure 10 shows a vertical cross-section of a fully wound and encased battery assembly. It will be seen that the cell elements are wound around20. central former 30 with positive and negative plate elements being juxtaposed and separated by separator sheets 25. The positive tabs 23 are connected to a radial terminal bar 37 which has an axially extending positive take off tab 36 positioned25. adjacent one end of the tube 30. The negative take off tabs 24 are similarly connected to a terminal bar 8 affording a tab 39. The regions 20 are fused both to the tube 30 and to each other to form an integral intercell partition between adjacent cells,30. there being three cells stacked one above the other 14.in disc form in the battery. The tube 30 has electro¬ lyte introduction holes 31 and it will be seen that these are juxtaposed to perforations formed in the pasted positive and negative plates which form more 5- or less continuous radially extending channels 40 shown in dotted lines in the right hand half of the drawing. The wound assembly is encapsulated in an appropriate sheet 41 which may be of a polymer compatible with the resin 20 so as to be heat sealed10. thereto or could merely be a shrink wrapped can. In addition a further shrink wrapping could be provided outside. In a further alternative the member 41 is both shrink wrapped and heat sealed simultaneously to the outer ring of the members 20 and the15- material 41 may be of the order of .005 τhick. The wrapped assembly would then be placed within an appropriately dimensioned outer canister and appropriate end seals provided, for example by • potting in hot melt adhesive or epoxy resin or20. forming a close fitting dish nesting over the terminals and take off lugs and then potting in an appropriate resin. It should be appreciated that the central core of the former 30 may be provided with appropriate venting means for example the rubber25. tube 35 described above with reference to Figure 5. The cell can then be provided with a small aperture at one or both ends rather than needing a separate venting arrangement to be incorporated within the end closure. Of course additional venting provisions at30. the ends of the cell are not υrecluded and in 15 .environments where flame proofing is required these venting arrangements can be provided. Indeed, if overally dimensions are critical this venting or additional venting could be located within the ends 5. of the tube 30.The method of assembly of the battery described above is as follows:Referring to Figure 3 four strips of lead sheet are expanded, preferably the expansion method being10. such as to ensure that the majority of the strands run transverse to the length of the strip rather than along the length of the strip. For the Figure 3 arrangement two strips will be terminal strips having one expanded portion and one solid edge15. portion and the other two strips will be expanded on both sides. The negative terminal stπp is then pasted with positive active material on its left hand side and the two intermediate strips with • negative active material on the right hand side and20. positive active material on the left-hand side and then the left-hand edge strip is pasted v/ith negative active material on the right hand side. Alternatively a universal paste can be used. The first strip is then fed to a conveyor belt and separator material25. folded round the positive strip from a feed coil.The second strip is then overlapped onto the enveloped positive, its positive enveloped v/ith separator material and the third strip laid down with its negative strip over-lapping the previous enveloped30. positive strip. The positive strip of this cell 16.element is then enveloped in separator and left-hand edge strip laid down with its negative laid over the positive of the previous cell element. The multi-element assembly is then fed along a conveyor 5. 100 as shown in Figure 11 beneath a multihead hot melt adhesive supplying station 111 positioned closely before the location of the core 30 in a winding mechanism having a belt 110. Four ribbons of hot melt adhesive composition are laid down on the10. unpasted regions between the positive and negative paste strips of the multi-element assembly. Figure 11 shov.'s the winding mechanism which we prefer to use. The core 30 is of the form shown in Figure 7 having an external step against which the15. input end of the multi-element assembly is butted. The hot melt adhesive is squeezed between the outside surface of the former 30 and the multi¬ element assembly by the tensioning force of the'wind¬ ing mechanism. Thus the winding mechanism has an20. upper front roller 105 and a lower front roller 106 the upper one of which is mounted on springs, as may be the lower one if desired, so that variable tension can be applied to the belt as it passes round the major proportion of the circumference of25. the former 30. The tensioning of these rollers also permits them to move apart as the radius of the wound pack increases as the winding progresses. The belt then passes round tv/o rear rollers, upper 107 and lower 108, and around a tensioning idler roller30. 109 as well. It will be appreciated that the ribbon 17 .of hot melt adhesive is carefully juxtaposed to the unpasted area of the multi-element assembly.Once the pack has been wound to its specified dimensions it is ejected from the winding mechanism5. and secured in place by either an adhesive wrapper or by the adhesive effect of the ribbon of hot melt adhesive. If an adhesive wrapper is used this can merely be attached to the end of the multi-element assembly and then the winding mechanism will10. automatically wind this round the pack. The secured pack is then ejected and may be shrink wrapped prior to placing into the protective canister.Whilst the cell has been described as being cylindrical, thus having a circular cross section,15. it will be appreciated that the advantages of ease of assembly and reduced intercell connector lengths can still be obtained even when other cross sections are used.20.25. . 18.The cells may be filled by immersion in electro¬ lyte and evacuation of air from the assembly. Alternatively the electrolyte could be injected into the cells, e.g. , under pressure. It is desirable for each cell to have at least two vents, one through which the electrolyte could be introduced and one through which the air could escape. If necessary, one or both of the vents can be sealed after introduction of the electrolyte and charging. Reference has been made above to expanded lead material, whilst this is preferred the electrode pairs could be made from thin cast grid form or wrought form or from fibrous supports provided with electrically conductive coatings or deposited conductors such as are dis- closed in the present applicants British applications Nos. 9876/76 and 15664/76. The grids are preferably 0.1 to 1.0 rams thick especially 0.5 to 0.8 mm thick. The preferred alloy is a lead calcium tin alloy prefer¬ ably containing 0.075 to 0.13 e.g., 0.08 to 0.09% calcium and 0.34% to 0.79% tin e.g., 0.4 to 0.8 of tin.Alternative alloys include 99.9% lead and antimonial alloys such as those disclosed in United States patents Nos. 3879217 and 3912537.As mentioned above, the individual electrode element or electrode pairs are preferably pasted with a universal paste composition since half of the electrode pair has to be converted to positive active material in one cell and the other half of the electrode pair has to be converted to negative active material in the adjacent cell. The mid point of the strip is left unpasted right . 19 .across its width for a few rams e.g., 0.5 to 10 rams or is cleaned after pasting, since this is the region at which it will pass from one cell to the other and the region where it it wished for the barrier or potting compound to form a seal.One suitable universal paste composition comprises;60lbs of Hardinge grey oxide12 grams of fibre82 grams of Vanisperse CB (a lignosulphonate material)3.47 litres of water1.93 litres of 1.400 sp. gravity sulphuric acid.This is readily converted electrochemically in the cell either to positive or negative active form. Details of Vanisperse C.B. are given in British patent specification No. 1396308.Any desired separator material may be used such as a dense fibrous material e.g. fibreglass or a microporous polymer sheet e.g. , PVC but thin separator materials are preferred.Especially for (so called) sealed cells, the separator is selected to have a good moisture retention, a good rate of wicking i.e., it picks up and permits liquids to wick rapidly through it by capillary action and a good gas (especially 0_) permeability so as to retain electrolyte within its pores readily and also permit rapid passage of gas through it even when contain¬ ing electrolyte. Dense glass fibre mats are especially satisfactory in these respects, for example, non-woven mats of very fine short staple glass fibres e.g, 0.2 to 10 microns in diameter and having surface areas of 0.1 to 20 square metres per gram of silica are very suitable. Dense mats made from such fibres, whilst being flexible and having high electrolyte absorption properties, also can have porosities as high as 85 to 95%.Alternatively the separator material 25 may be about 0.2 rams thick a'nd have a tensile strength in the2 2 machine direction of 150 Kgs/cm and 130 Kgs/cm in the transverse direction an average pore size of 1 micron and an elongation at break of 100% in the machine direction. Such a material is madeby biaxially stretch¬ ing a chill roll cast film of high density polyethylene and is sold by the Sekisui Chemical Co. as PCM separator film.The separator material may thus have a thickness in the range 0.1 to 0.3 rams, a tensile strength of 15 to 200 preferably 50 to 160 Kgs/cm 2 , an elongation at break of 50 to 150%, a Gurley stiffness of 1 to 50 mg preferably 5 to 20 mg and a pore size of 0.1 to 10 microns preferably 0.5 to 5 microns.Any potting material which has an adequate resistance to attack by acid and can' form an electrolyte resistant seal with lead may be used for the partitions between cells and for the seals, but epoxy resins and polyolefin based hot melt adhesives are satisfactory.Suitable polyolefin hot melt adhesives include those comprising: A. A high molecular weight polyolefin component .21.e.g., polyethylene or polypropylene providing viscocity to the melt and cohesive strength to the solid,B. as a tackifying agent, a synthetic or natural resin, e.g., a wood resin or a derivative thereof to add tack and fluidity and premote wetting action,C. a plasticizer, e.g., a paraffin wax to lower the viscocity of the mixture for easier application, andD. a small amount of an a tioxidant.One suitable proprietory hot melt adhesive is that sold by Eastman Kodak as EASTOBOND A381S which is a polyolefin based material. Aς3.2_ As an alternative to universal paste the positive expanded mesh may be made and pasted separately from the negative expanded mesh of each electrode pair and they may be joined by a continuous seam weld 1 - 5 rams wide by means of overlapped perforated solid selvedges 2 to 10 rams wide. The selvedge can have 1 circular perforation 1 - 5 mms in diameter each 1 cms.Each positive mesh before pasting preferably has more lead e.g., 5 to 20% more lead, than the negative mesh. The positive electrodes may be pasted with the following paste composition:1000 kgs Activematerial comprising 40% lead and 60% lead monoxide, 297.9 litres water, 156.1 litres sulphuric acid (1.4 sp.gr.) and 4.5 kgs of amorphous silica (Gasil 23) .The negative electrodes may be pasted with the following paste composition:1091 Kgs. leady oxide, 302 kgs. of Vanisperse CB lignosulphonate, 5.5 kgs. of Barium sulphate,-BU EAUO PI WIP0 .22.0.23 kgs. of Fibre, 0.57 kgs. of antioxidant (stearic acid), 1.8 kgs. of carbon black, 122 litres of water and 70 litres of sulphuric acid (1.4 sp.gr.). . .INDUSTRIAL APPLICABILITYThe battery system of the. present invention may be used for conventional sealed cell applications such as in hand held powered tools where the ability to function in any orientation is required. It may also be used when appropriately dimensioned as a car starter battery and may be either sealed or flooded for this application. It-may also be used for floating charge standby applications.IJΪJRΏTΓOMPI | . 24 .CLAIMS1. A multicell battery characterised in that it is spirally wound, the cells are coaxial and are divided from each other by partitions disposed transverse to the said axis and the cells are interconnected by portions of the plates which pass through the said partitions2. A battery as claimed in Claim 1 in which the cells are of annular form and are arranged around a central former.3. A battery as claimed in Claim 2 including a seal between each partition and the former, outer container means enclosing the outer circumference of the annular cells, a seal being provided between the said outer container means and the outer peripheral edge of each partition.4. A battery as claimed in Claim 2 or Claim 3 in which electrolyte access and venting means are provided in the former for each cell.5. A battery as claimed in Claim 4 in which the access and venting means is a single hole for each cell which is occluded by a resilient lining tube located inside the former.6. A battery as claimed in any one of Claims 1-5 in which the plates comprise current conducting elements of expanded metal and the majority of the mesh elements extend transverse to the length of the strip so as to shorten the current pathways between adjacent cells.OMPI 7. A battery as claimed in any one of Claims 1-6 in which the portions of the plates which extend through the partitions are apertured and the apertures are filled with the material of the partitions.8. A battery as claimed in any one of Claims 1-7 in which each plate has a pair of active material carrying portions extending along its length with an intercell conductor portion located therebetween, the intercell conductor portions having a greater cross sectional area of metal per unit length than the active material carrying portions.9. A method of making a multicell electric storage battery of spirally wound construction as claimed in Claim 1 which comprises providing a number of longitudinally extending electrode affording members with a positive active material strip along one side and a negative active material strip along the other *side, direct electrical interconnection being provided between the strips of opposite polarity along the full length of the electrode member, either continuously or discontinuously> a partition region free of active material being disposed between the two active material strips, arid providing one positive terminal strip having a continuous current taken off band along one edge and a negative active material strip electrically connected thereto along the other edge, a partition region free of active material being disposed between the take off band and the active material strip, and one negative terminal strip having a continuous current take off band along one edge and a positive active material .26 .strip electrically connected thereto along the other edge, a partition region free of active material being disposed between the take off band and the active material strip, overlapping positive active material strips with negative active material strips, with interleaved and separator materia3/covering the free face of at least all the negative strips or at least all the positive strips with separator material, presenting one end of the overlapped strips to the surface of a former and winding the assembly around the former into a pack, with separator material between contacting faces of active material, each partition region being supplied with partition polymer material compatible with the material of the former and effective to produce an electrolyte impervious seal therewith, the partition polymer material being supplied in such condition and or shape as to form a continuous electrolyte impervious seal with its own juxtaposed surface between each turn of the spirally wound pack whereby an annular electrolyte impervious partition between adjacent cells is formed in the fully wound cell, the partition polymer material being supplied to each partition region either before the assembly is wound round the former, or whilst it is being wound round the former and providing an outer container forming a seal with the outer peripheral edge of each partition between the cells.10. A method as claimed in Claim 9 in which the partition region is provided continuously with hot melt adhesive in a hot adhesive state immediately prior to the moment when the portion of the region which is being supplied with hot melt adhesive is pressed against the outer surface of the hot melt adhesive in the partition region previously supplied and already wound.OMPI | CHLORIDE GROUP LTD; PEARSON E | PEARSON E |
WO-1979000230-A1 | 1,979,000,230 | WO | A1 | XX | 19,790,503 | 1,979 | 20,090,507 | new | C02C5 | B01D35 | B03C1, C02F1 | B03C 1/00B, B03C 1/015, B03C 1/025, C02F 1/48K, C02F 1/52, C02F 1/52F | A METHOD AND AN AGENT FOR CHEMICAL PURIFICATION OF WATER BY MEANS OF CHEMICAL PRECIPITATION AND MAGNETIC SLUDGE SEPARATION | A method and an agent for chemical purification of water is provided, especially waste water with subsequent magnetic sludge separation. A precipitation agent comprising as component aluminium sulphate and/or iron sulphate is used together with a magnetic material for the purification. In order to provide uniform distribution of the magnetic material in the agent composition it is added to the aluminium and/or iron sulphate component of the composition when said component is in the form of a melt or solution prior to crystallization of said composition. | A METHOD AND AN AGENT FOR CHEMICAL PURIFICATION OF WATER BY MEANS OF CHEMICAL PRECIPITATION AND MAGNETIC SLUDGE SEPARATION The present invention relates to a method-and an agent for chemical pu¬ rification of water, especially wastewater with subsequent magnetic sludge separation. A precipitation agent or precipitant based on alumi¬ nium sulphate or iron sulphate is used together with a magnetic material for the purification.In chemical purification of wastewater, a chemical is added to the water which is precipitated in the wastewater in the form of flocculated che¬ mical compounds. The primary task of the added chemical is to precipi- tate the phosphates dissolved in the wastewater, which would otherwise result in fertilization of the receiving body of water. Furthermore, metals present in the water are precipitated to a large extent. The floes have the ability of thereby effectively binding any substances suspended in the wastewater. By this treatment there is thus obtained a clear water, to a large extent liberated from suspended substances, bac¬ teria, viruses, metals and phosphates. The content of oxygen-consuming organic substance falls considerably in this treatment.The sludge formed in the process sketched above, and containing the i - purities, is separated in conventional wastewater treatment plants by sedimentation or flotation. These operations are relatively voluminous since they cannot be carried out at high surface load. Sedimentation is3 2 generally carried out at a surface load as low as about 1 m /m x h and3 2 flotation at a maximum surface load of about 5-10 m /m x h. As an alternative to this conventional sedimentation or flotation, mag¬ netic separation has been brought in, which enables the removal of par¬ ticles down to colloidal size from many types of wastewater. The basic technique was originally developed at the end of the sixties in con- nection with the solution to the problem of removing ~ry fine paramag¬ netic discolouring particles from kaolin clays used in the production of paper. It was quickly appreciated that the new technique was not limited solely to the treatment of kaolin clays, and could also be used for treating wastewater. It was then found that with the technique of ag- OMPI -A linn--- netic sludge separation the surface load could be increased substant-3 2 ially also, right up to about 50-200 /m x h. This has the advantage that magnetic sludge separation requires less space than conventional sludge separation. To obtain an approximate idea of the differences, a plant for magnetic sludge separation can be compared to a plant hav¬ ing the same capacity for sedimentation, the former requiring at most 1/10 as great a space as the latter.Attempts have been made to utilize conventional flocculation agents in combination with magnetic material for purifying wastewater in a more effective and less voluminous way. Mechanical blending of, for example, aluminium sulphate and magnetic material has been used for this purpose, but it has been found difficult to provide even distribution of the mag¬ netic material in the floes formed. Such even distribution of the magne- tic material is necessary for the sludge separation to be carried out in an effective manner.According to the invention it has now been surprisingly found that if a composition is used as precipitant, this composition being obtained by adding the magnetic material to the flocculation chemicals of the preci¬ pitant when it is in the form of a melt or solution* very uniform dist¬ ribution of the magnetic material in conjunction with flocculation can be obtained, and thereby a more effective separation of the floes formed as well. The precipitants of interest in conjunction with the invention are aluminium sulphate and/or iron(II)sulphate. A preferred flocculant is aluminium sulphate which, when it is present as a melt, easily allows itself to be blended with the magnetic material, whereby the crystalli¬ sation of the melt under stirring leads to the formation of a composi¬ tion based on aluminium sulphate in which the magnetic material is very evenly distributed. Iron(II)sulphate is also amenable to be transferred into a melt or solution, but in this case some water must be added for maintaining the right water content, to compensate for the water which . is driven off by vaporization in connection with melting the iron sul¬ phate.By magnetic materials are meant here and in the following such mate¬ rials which are attracted by magnets, i.e. materials that can be sepa--xZVREAΪ O PI rated with the help of magnetic fields. Magnetic materials thus com¬ prise ferromagnetic materials, which are attracted already by relati¬ vely weak magnets, and paramagnetic materials which can be attracted by stronger magnets, e.g. of the high-gradient type which can achieve a magnetic flux density of about 2 tesla (20000 gauss) and above, or such superconductive types with a maximum magnetic flux density of 10-15 tesla. Included in the ferromagnetic materials are iron, nickel and cobalt, as well as certain alloys and oxides of these substances. Such magnetic materials based on iron are, of course, to be preferred due to their easy availability and low price. The use of iron oxides is especially preferred. The magnetic material used in the present inven¬ tion thus expediently consists of magnetite or other magnetic iron ox¬ ide, such as the iron oxide obtained in magnetite - yielding roasting of pyrites or other materials containing iron sulphide.Seen in percent by weight, the magnetic material preferably constitu¬ tes the minor portion of the composition, e.g. 1-50 percent by weight, suitably 2-30 percent by weight and especially 3-10 percent by weight of the composition.The invention thus relates to a process for chemical purification of water with subsequent magnetic sludge separation, and to an agent for carrying out this method. Remaining characterizing features of the in¬ vention are apparent from the patent claims. The invention will now be described in detail by means of non-restricting examples in conjunction with the appended drawing, which diagrammatically shows a system for magnetic separation used in the development of the technique according to the present invention.The apparatus shown diagrammatically on the attached drawing is based on a Sala-HGMS magnetic separator (from Sala International, Sala, Sweden). The central portion of the plant consists of a magnet generally denoted by the numeral 1, provided with a matrix-containing through- flow tube 2 having a diameter of about 10 cm and a length of about 15 cm. In the present experiments, a matrix 3 of expanded metal was used, i.e. a metal given a wire-netting-like appearance, which was packed complet- ely randomly. The magnet was otherwise conventionally provided with an iron core 4 and a magnet winding 5.Vertically above the matrix 3 there is arranged a flocculation vessel 6 provided with a propeller st rrer 7 and interior baffles, not shown. This flocculation vessel 6 is connected to the matrix 3 by means of a pipe 8. In the embodiment in question, the flocculation vessel 6 has a volume of about 20 liters while the pipe 8 has a bore of about 10 mm.Associated with the magnetic separator there is a current supply unit 9, a heat exchanger 10 for cooling water, and a control panel 11 for regu¬ lating valves etc. The current supply is adjustable in eight steps, and the magnetic flux density achieved is in the range 0-2.0 T (tesla). The water flow through the apparatus is regulated by a throttle valve 13 in the outlet pipe 12 downstream of the magnet. The valve 13 is controlled by the control panel 11 through regulator 14. Purified water leaves the apparatus as indicated by arrow 15. The load is given in meters per hour (m/h) calculated on the cross sectional area of the through-flow tube. Side pipes 16, 17 with associated shut-off valves 18, 19 controlled by the control panel 11 through regulators 20, 21 are arranged for counter flushing, to clean the matrix. Water is lead to pipe 16 as indi¬ cated by arrow and out from pipe 17 as indicated by arrow. When per¬ forming counter flushing the pipes 8, 12 are shut off by shut-off valves 13, 22 associated with regulators 14, 23. The regulators 14, 20, 21 and • 23 are controlled via conduits from control panel 11 as indicated at 24. The current supply to magnet 1 and control panel 11 is taken from current supply unit 9 as indicated by conduits 25. The heat exchanger 10 cools outgoing cooling water from the magnet 1 as indicated by conduit 26 and may also influence the power supply as indicated by connection 27.So-called beaker experiments were carried out using 1-liter glass beak¬ ers provided with gate sti rers with the object of finding out whether addition of magnetic material has any disturbing effect on the floccula¬ tion. The flocculation chemicals were added as a 10 percent by weight so- lution during a quick admixture of 5-10 seconds, whereafter stirring was reduced to a peripheral speed of the stirrer of about 0.1 m/sec, for aρUREΛ ?sJ)MPI_ flocculation period of 10 minutes. After 10 minutes sedimentation, 100ml samples were decanted for analysis with respect to turbidity (JTU; Jackson Turbidity Units) and total phosphorus (Ptot) in mg/1.The experiments in the magnetic separation apparatus described above were carried out in batches in such a way that the whole system was filled with drinking water up to the bottom of the flocculation vessel 6. All valves were subsequently closed and 5 liters of wastewater was transferred to the flocculation vessel. Dosing of the chemicals was car¬ ried out with a 10 percent by weight solution during a rapid admixture for 10 seconds. Stirring was thereafter reduced to the lowest possible, i.e. about 30 revolutions per minute for 5 minutes for flocculation. The water is thereafter allowed to pass through the magnetic separator under gravity, and samples for analysis were taken out after 3 liters of water had passed through the magnetic separator. The experiments were carried out at varying loads and with varying magnetic flux density. In the per- culation tube, the load was thus varied between 62 and 470 meters per hour and the magnetic flux density between 0.07 and 1.60 T. It was found that the purification effect deteriorated with increased load or falling flux density. The values selected for the experiments represent suitable experimental conditions in the apparatus used. After each experiment, the current supply was cut off and the matrix was flushed clean by means of the counter flushing arrangement. Samples taken were analyzed for turbidity and total phosphorus.Some of the experimental results are given in the tables 1-3 below. The flocculation chemicals used in the experiments are wastewater grade alu¬ minium sulphate (AVR), to which, while in the form of a melt had been added 5 percent by weight of magnetite or 1-20 percent by weight of iron oxide (JOX). AVR is a special chemical for wastewater purification, con¬ taining active aluminium, iron and silicon compounds. Its chemical com¬ position is as follows:Al appr. 7 %Fe 3 % Sulphuric acid deficiency 1 %Waterinsoluble 2.5 % Active substance 3.2 moles/kgAluminium is present as Al2 (S04)3 • 16-17 H20Iron is present as Fe2(S0.)3 • 9 H20The water-insoluble part consists mainly of silicate mineral.The AVR with the addition of magnetic material has been produced in the laboratory especially for these experiments. A mechanical mixture of AVR and magnetic material has been prepared, as well as a mixture con¬ sisting of magnetic material added to the final solution in connection with the normal AVR-manufacture. The AVR solution or melt, and the mag¬ netic material are blended by stirring for 5 minutes, after which the melt is allowed to solidify while forming the solid crystalline product with the magnetic material uniformly distributed therein. The product is crushed and dissolved in water to a content of about 10 percent by weight for use as a flocculation chemical.The magnetite used in the experiments is of laboratory quality, puriss(Kebo). The iron oxide (JOX) comes from a sulphuric acid factory and2+ contains 65.8 % ^e+0 » 0-5 % being Fe . For a magnetic flux density of 0.15 T the iron oxide contains 24.5 % magnetic material.Wastewater used for the experiments was collected daily from Sala Mu¬ nicipality Wastewater Treatment Works, which is a conventional plant3 working with postprecipitation and an AVR dosage of 75 g/m .Table 1Experiments with biologically purified wastewaterExperiment Chemical Pt.ot. mιg/1 Turbidity JTU1 Untreated water 0.59 9.82 75 mg/1 AVR 0.15 123 75 mg/1 AVR + 5 % magnetite 0.18 124 0.08 4.55 0.20 8.5Experiment 1 relates to assessment of the unpurified wastewater without any treatment. Experiments 2 and 3 relate to beaker experiments, experi- ent 2 solely using conventional flocculating agent (AVR) and experi¬ ment 3 being performed in beakers with AVR containing 5 percent by weight magnetite in a fused-in homogeneous form. Sludge separation takes place here by sedimentation. Experiment 4 relates to the use of the same flocculation agent as in Experiment 3, but carried out with magnetic se¬ paration. Finally, Experiment 5 relates to magnetic separation carried out with a solely mechanically blended composition of AVR and magne¬ tite. During the magnetic separation a load of 62 m/h and a magnetic flux density of 0.47 T were used.The effect of applying the technique according to the present invention is directly apparent from a comparison between the Experiments 4 and 5, where Experiment 4, according to the table, gives substantially better purification, both with regard to the figure for P. . and for turbidity.Table 2.Further experiments carried out with varying compositions.Load: 62 m/h Magnetii : flux density: 0.47 TExperiment Chemicals 1 Ptot m /] Turbidity JTU6 Untreated water 0.72 117 75 mg/1 AVR, plus5 % fused-in magnetite 0.07 4.28 75 mg/1 AVR plus 5 % fused-in ground magnetite 0.17 4.09 75 mg/1 AVR plus y 1 % fused-in JOX 0.32 1810 75 mg/1 AVR plus 1 % fused-in ground JOX 0.38 1711 75 mg/1 AVR plus 1 % JOX, mechanical blend 0.43 1812 75 mg/1 AVR plus 5 % fused-in JOX 0.12 6.113 75 mg/1 AVR plus 5 % fused-in ground JOX 0.13 6.714 75 mg/1 AVR plus 5 % JOX, mechanical blend 0.35 2015 75 mg/1 AVR plus10 % fused-in JOX 0.20 8.2 16 75 mg/1 AVR 0.29 23x) Iron oxideThe technical effect on applying the technique according to the present invention will be seen from this table, i.e. in comparing between the examples 13 and 14, for example with fused-in and mechanically blended iron oxide. It is also apparent from the table that the use of 5 percent by weight of ferromagnetic material gives the best effect. In Experi¬ ments 8, 10 and 13 magnetic material was used which was ground for 8 minutes in a shatter box mill. This grinding operation did not appear to have any substantial effect.Table 3. The effect of the time for adding magnetite in experiments with biologically purified wastewater.Load: 62 m/h Magnetic flux density: 0.47 TChemical dosage: 75 mg/1 AVR + 3.75 mg/1 magnetiteMagnetite addition tot mg/1 Turbidity JTU1 minute before adding AVR 0.15 12Fused-in into AVR 0.07 6.51 minute after adding AVR 0.16 13The advantage with fusing-in the magnetite into the aluminium sulphate will be seen immediately from these experimental results, compared with separate addition, independent of whether the latter takes place before or after the addition of aluminium sulphate.Tentative experiments have shown that the use of paramagnetic substances, such as oxides and hydroxides of manganese, chromium and tri-valent iron (hematite) give similar results to the above for ferromagnetic substan¬ ces. However, a higher magnetic flux density and/or lower water flow rate is required when using paramagnetic substances, than for the use of ferromagnetic additives to achieve the same amount of purification.Further experiments have shown that the grain size of the magnetic ma- UREAZOMPI terial used has an influence of great importance on the purifying re¬ sult.Thus, small grain sizes have shown to provide that no substantial sedi- mentation of the magnetic material occurs and that all floes which are formed at the chemical precipitation will contain magnetic material.The importance of the grain size is illustrated of the following results, ■ which have been obtained when performing a chemical precipitation of biologically purified waste water and a subsequent magnetic sludge sepa¬ ration. The waste water had previous to the precipitation a content of total phosphorus (Pt t) of 2.3 mg/1 in test run I and 1.1 mg/1 in test run II, respectively. The precipitation was carried out by means of 150 mg/1 AVR containing 5% by weight fused-in magnetite. The magnetic flux density of the used magnet was 0.1 T and the surface load was approxi¬ mately 100 m/h. The grain size is given as the grain size median, i.e. 50% by weight of the material has smaller grain sizes than the median value.Magnetic material Phosphorus content grain size separated u mg/1I II2.5 1.30 0.50 8 0.70 0.35 16 0.60 0.25 30 0.50 0.25 75 0.40 0.20The obtained results unequivocally exhibit that the purifying effect in¬ creases with decreasing grain size and with increasing P. . previous to precipitation and that the grains should be at least below 8 Aim, prefer¬ ably below 3 i-m in size.It has also been found possible to incorporate activated carbon into the precipitant composition while in a molten state, the carbon also being evenly distributed in the crystallized product. The advantage of having activated carbon in the product is that it has the ability of absorbing dissolved organic compounds out of the wastewater, these compounds not being usually removed in chemical purification. Since such compounds are often of a toxic nature, it will be seen that treatment of wastewater with active carbon is of great value. It has been found that a composi¬ tion of the kind described hereinbefore, containing about 10 percent active carbon, apart from about 5 percent magnetite, for example, and at a dosage of 75 mg/1 has the ability of removing up to 3 mg per liter dis¬ solved organic substance, in addition to the amount removed by a composi- tion not containing activated carbon. | CLAIMS : -1. A method of chemically purifying water with subsequent magnetic sludge separation, the purification being carried out while using a crystalline precipitant based on A!,,(SO.), and/or FeSO., together with a magnetic material, characterized by using as a precipitant a compo- sition which, for attaining uniform distribution of the magnetic mate¬ rial in the composition, is obtained by adding the magnetic material to the A12(S0.)3 or FeSO. component of the precipitant when it is in the form of a melt or solution prior to crystallization.2. A method as claimed in claim 1, characterized in that the magnetic material consists of magnetite or other magnetic iron oxide, such as is obtained in magnetite yielding roasting of pyrites.3. A method as claimed in claim 1, characterized in that the magnetic material constitutes 1-50, preferably 2-30, and especially 3-10 percent by weight of the composition.4. A method as claimed in any of the preceding claims, characterized in that the magnetic material has a grain size median substantially below 8 ^ιm, preferably below 3 yum.5. A method as claimed in any of the preceding claims, characterized in that there is used as precipitant a composition also containing activa¬ ted carbon.6. A precipitant for carrying out the method according to claim 1, for chemical purification of water with subsequent magnetic sludge separation, purification being carried out while using a crystalline precipitant based on A12(S0.)3 and/or FeSO,, together with a magnetic material, characterized in that it consists of a composition which, for attaining uniform distribution of the magnetic material in the com¬ position, has been obtained by the addition of the magnetic material to the A12(S04)3 and/or FeSO^ component of the precipitant when this is in the form of a melt or solution before crystallization.7. A precipitant as claimed in claim 6, characterized in that the mag- JUREATΓOMPI netic material consists of magnetite or other magnetic iron oxide, e.g. obtained in magnetite yielding roasting of pyrites.8. A precipitant as claimed in claim 6 or 7, characterized in that the magnetic material constitutes 1-50, preferably 2-30, and especially3-10 percent by weight of the composition.9. A precipitant as claimed in any of the preceding claims, character¬ ized in that the magnetic material has a grain size median substant- ially below 8 urn, preferably below 3 um.10. A precipitant as claimed in any of claims 6-9, characterized in that the composition also contains activated carbon. AMEN L(received by the International Bureau on 2 March 1979 (02.03.79))1. A method of chemically purifying water with subsequent magnetic sludge separation, the purification being carried out while using a crystalline precipitant based on A12(S04)3 and/or FeSO-, together with a magnetic material, characterized by using as a precipitant a solid, crystalline composition which, for attaining uniform distribution of the magnetic material in the composition, is obtained by adding the magnetic material to the A12(S0.)3 or FeSO. component of the precipitant when it is in the form of a melt or solution prior to crystallization.2. A method as claimed in claim 1, characterized in that the magnetic material consists of magnetite or other magnetic iron oxide, such as is obtained in magnetite yielding roasting of pyrites.3. A method as claimed in claim 1, characterized in that the magnetic material constitutes 1-50, preferably 2-30, and especially 3-10 percent by weight of the composition.4. A method as claimed in any of the preceding claims, characterized in that the magnetic material has a grain size median substantially below 8 μm, preferably below 3 μm.5. A method as claimed in any of the preceding claims, characterized in that there is used as precipitant a composition also containing activa¬ ted carbon.6. A precipitant for carrying out the method according to claim 1, for chemical purification of water with subsequent magnetic sludge separation, purification being carried out while using a crystalline precipitant based on A12(S0.)3 and/or FeSO., together with a magnetic material, characterized in that it consists of a solid, crystalline com¬ position which, for attaining uniform distribution of the magnetic mate¬ rial in the composition, has been obtained by the addition of the mag¬ netic material to the A12(S0.)3 and/or FeSO. component of the precipi¬ tant when this is in the form of a melt or solution before crystallization. f-BUREAUO PI y. STATEMENT UNDER ARΗCLE 19This is in reply to the international search report of 1979-01-18. Considering the documents found in the inter¬ national search report we file a new page 11, where we have made the following amendments:The words solid, crystalline have been inserted in our claim 1 line 4 after as a precipitant a - and in our claim 6 line 30 after it consists of a - .These amendments are based upon what is said on page 6 line 12 in the description, and are made for the purpose of showing in a more clear way how the invention differs from the prior art.Further, the amendments have only a minute impact on the description since one of the essential objectives of the invention is the use of a solid agent as a precipitant. However, to uniform the description and the claims the words solid, crystalline could be inserted on page 2 line 28 after the formation of a - , even though it is said on page 2 l ne 26-28 that the melt is crystallized.lϊU EA^OMPI | BOLIDEN AB; SIGVARD H | SIGVARD H |
WO-1979000260-A1 | 1,979,000,260 | WO | A1 | XX | 19,790,517 | 1,979 | 20,090,507 | new | G01S3 | H04N7, G01S7 | G01S3, G01S13, G06T1, H04N5, H04N7 | G01S 13/72B, G01S 3/786C1 | CORRELATION FOLLOWER FOR TRACKING AN OBJECT | A correlation follower comprising an image sensor (1) adjustable sideways and in height with a limited field of view, which is cyclically scanned by the sensor the output signal of which reflects the image content within the field of view and a video correlator (3) for controlling the alignment of the sensor in dependance of the output signal of the image sensor. The video correlator (3) has two addressable memories (12, 14) the one of which is a real time memory (12), i.e. in this memory a section of the field of view is stored for each cycle. The other memory is a reference image memory (14) and is updated with the content or the real time memory (12). During the correlation the contents of the memories are displaced in relation to each other and an error signal, corresponding to the position of displacement for which maximum correlation is achieved, is made to control, through said control circuits, the alignment of the sensor. To make the tracking process insensitive to disturbancies and image elements which appear momentarily in the field of view for each scanning cycle only a part of the positions of the reference image memory (14) are updated by selection the addresses to said positions randomly or according to a predetermined rule of selection. By that the positions which are updated during one cycle in positions are distributed over the entire area of the memory. | Correlation follower for tracking an objectTechnical fieldThe present invention relates to a correlation follower for track¬ ing an object, comprising an image sensor having a limited field of view and arranged to scan said field of view cyclically and to supply, in preselected form, a video signal representing the field of view, a video correlator with two addressable memories, one of which has the object of storing in digital form for each scanning cycle one section of the field of view, while the other memory is arranged to be updated with the content of the first memory, said video correlator being arranged to produce, once the image sensor has been so aligned that an object is encompassed within the sec¬ tion, an error signal controlling the alignment of the image sen- sor with the object, said error signal corresponding to a dis¬ placement of the section in the first memory relative to the sec- tion in the other memory, for which displacement a maximum corre¬ lation is achieved between the contents of the memories.Background artBy correlation one can get, according to a predetermined rule of evaluation, a measure of how well the contents of the memories coincide at different relative displacements.Essential for the correlation and hence also for the tracking process is the way in which the other memory, subsequently referr- ed to as the reference image memory, is updated. At known corre¬ lation followers, see e.g. US Patent No. 3 828 122, updating is brought about in the course of one single scanning cycle, either periodically the updating process being repeated after a certain number of cycles, or when the maximum correlation drops below a preselected value. If an image element irrelevant to the track¬ ing process appears momentarily in the section the former updat¬ ing alternative entails the danger of the reference image memory being updated precisely when the image element appears, which may jeopardise the tracking process. With the other updating alternative the appearance of the image element may trigger up-« dating of the reference image memory. This leads in practice to tracking of the irrelevant image element.The object of the present invention is to bring about such updat¬ ing of the reference image memory that the above disadvantages are avoided and this is enabled in that the video correlator has means arranged to select at each scanning cycle addresses of posi¬ tions in the latter memory for the purpose of updating said memory randomly or according to a predetermined rule of selection so that said memory at each scanning cycle is updated only partly and in positions that are distributed over the area of the memory.Description of the drawing The invention is further explained below with reference to the attached drawing in which fig.l is a block diagram showing schema¬ tically the design of a correlation follower, fig.2 is a block diagram showing the design of a video correlator and fig. is a block diagram showing how updating is effected according to the invention.Description of a preferred embodimentIn fig. 1 an image sensor of known type and consisting of a TV or IR camera with a field of view restricted in space is design- ated 1. The sensor is mounted on a platform 2 capable of being adjusted both sideways and in height and is so designed as to scan the field of view cyclically and to supply a video signal which reflects the image content within the field of view in electric form. The video signal is supplied, via a video corre- lator 3 connected with the sensor 1, to a monitor 4 on screen 5 of which the sensor's field of view is displayed. A cursor is superimposed over the video signal in the video correlator 3, the position of which on the monitor screen 5 is shown as a window 6 which an operator can move, with the aid of a control lever 7, to any position on the screen. Also the size of window 6 can be varied with the aid of control lever 7 and the said sizeOM so selected that the image 9 of an object 8 on screen 5 fits exactly within the window. In this way the effect of inter¬ ference from the surroundings of the object can be minimised, i.e. irrelevant background contrasts are screened off. Using control lever 7 the operator can also align the sensor 1 with object 8 and get the correlation follower to lock on the latter. In this process aligning signals from control lever 7 are trans¬ mitted via the video correlator 3 to an electronic platform system 10 in.which the aligning signals are converted into control signals for aligning the platform 2 and hence the sensor 1 both laterally and in height. After locking on, the sensor 1 tracks the movements of the object 8, whereby an error signal is extract¬ ed from the video signal of sensor 1 by means of a correlation process, which will be discussed in connection with fig. 2, the said error signal being converted in the electronic platform system 10 into control signals for aligning the sensor 1 as de¬ scribed above in connection with control lever 7.In fig. 2 twin-line arrows illustrate a flow of image information. This flow of information reaches an analog/digital-converter 11 from an image sensor of the above described type which is not shown in the figure. The A/D-converter 11 is designed to convert an analog video signal from the image sensor, the amplitude of which corresponds to the contrast at each point within the field of view of the sensor, to a digital signal containing in binary coded form the same data as the video signal. A part of the digital signal corresponding to the said section of the field of view of the sensor is read, during each scanning cycle, into a memory 12, designated henceforth as the real time memory. The reason for the designation real time memory consists in the fact that the information stored in the real time memory in real time corresponds to the image content in the scanned section. From the real time memory 12 the flow of image information passes, on the other hand, via an updating date 13 to a memory 14, which is the above-mentioned reference image memory, and on the other hand to a correlation computing circuit 15 which also receivesOMPI image information from the reference image memory 14 forming an output from the latter. In the same way the designation refer¬ ence image memory points to the fact that this memory is to serve as a reference during the correlation process. The flow of image information is controlled by a control logic 15 in accordance with the result of the correlation circuit measure¬ ment as will be described below.As previously stated the image sensor can be made to lock on to the object, by means of- the control lever 7. When this is the case the content of the real time memory 12 is copied, during one scanning cycle, into the reference image memory 14. In the course of each scanning cycle, i.e. with each image read into the real time memory 12, the contents of the two memories are compared in the correlation computing circuit 15, the said con¬ tents being placed in different positions relative to one another. The comparison may be effected in accordance with any known method of correlation by means of which a factor of merit is calculated for each relative position of the image information in the two memories 12, 14. The relative position in which the highest factor of merit, i.e. the maximum correlation, occurs, is stored in a memory 17. Depending on the relative position in which maximum correlation is achieved the control logic 16 controls the flow of image information, i.e. the correlation computing process and the updating of the reference image memory 14. The control logic 16 has also the object to regulate, in response to signals from the control lever 7, the arrangement of window 6 and to supply error signals to the electronic platform system 10.Updating in accordance with the invention of the reference image memory 14 will now be explained with reference to fig. 3 in which as before twin-line arrows illustrate the flow of image informa¬ tion.In fig. 3 which shows especially how the real time memory 12 and the reference image memory 14 are addressed and the latter memoryOM is updated, 18 designates an address counter by means of which partial elements in the memories 12, 14 are addressed sequenti¬ ally via the address correction circuits 19 och 20, respectively, so that these are passed through line for line until all partial elements have been covered. The address correction circuits 19, 20 are controlled by memory 17,as regards the relative displace¬ ment between the contents of the memories at which the highest factor of merit is achieved as described above. The amplitude values in the partial elements addressed during this process in the respective memory are read into an amplitude logic 21 or a balancing circuit in which, according to a special characteristic of the invention, the amplitude values in corresponding positions are combined with one another, it being stated according to a criterion applying to each combination of amplitude values with which amplitude value the addressed position in the reference image memory 14 is to be updated. Such a criterion may be, for instance, that with quick or large changes in contrast, i.e. with large amplitude differences between the contents in the addressed partial elements, a mean value should be formed by means of which the partial element in the reference image memory is updated.This is equivalent to a certain filtration which prevents track¬ ing of any image element which suddenly appears in the field of view. If the amplitude values in two corresponding positions are equal, updating will of course take place with this value, i.e. the content of the partial element in the reference image memory remains unchanged.According to the primary characteristics of the invention updating shall occur randomly or according to a predetermined rule of selection so that during each scanning cycle the memory is up¬ dated only partly and in positions that are distributed over the area of the memory. This is achieved by that the amplitude value stated in accordance with the above criterion being fed to the addressed partial element in the reference image memory 14 via a gate 22 controlled by a prime or random number generator 23. With prime number generation the control operates in such a way as to ensure that the gate 22 is opened for each p-th of the partial elements addressed by the address counter 18, p being a prime number the size of which is selected with a view of the required updating rate. Should p be set to 1 this would mean that the entire reference image memory 14 would be updated during one single scanning cycle as described above. Therefore the prime number is at least equal to 3. With random number genera¬ tion the gate 21 is opened once the address counter 17 has counted forward s partial elements, s being a random number, e.g. from a table of random numbers. Whenever the gate 21 is opened a new random number is supplied. In this case the updating rate varies owing to selection of different mean values for the table of random numbers.By that the updating is carried out according to the invention and thus is neither related to the result of the correlation nor carried out periodically, it is achieved that with great probabi¬ lity the reference image memory will not contains disturbing image elements and such that suddenly occur in the field of view of the sensor. This means that a correlation follower, the updating of the reference image memory of which is carried out as described above, is difficult to disturb and therefore the tracking of an object can be carried out with high accuracy.It is obvious that the invention can be modified in many ways within the scope of the inventive idea. It is possible, for instance, to utilize the video signals from a radar station for tracking an object. Further the updating may be carried out according to some other rule of selection than described above, e.g. according to a fixed pattern that is moved successively over the area of the memory., . WI | Claims1. A correlation follower for tracking an object, comprising an image sensor having a limited field of view and arranged to cyclically scan said field of view and to supply, in a preselected form, a video signal corresponding to the field of view, and a video correlator with two addressable memories one of which has the object of storing in 'digital form for each scanning cycle a section of the field of view while the other memory is arranged to be updated with the contents of the first memory, said video correlator being arranged to produce, once the image sensor has been so aligned that an object. is encompassed within the section, an error signal controlling the alignment of the image sensor with the object, said error signal corresponding to a displacement of the sec¬ tion in the first memory relative to the section in the other memory for which displacement a maximum correlation is achiev¬ ed between the contents of the memories, c h a r a c t e r-.. i s e d . in that the video correlator (3) has means (21, 22) arranged to select, for the purpose of updating the other memory (14), addresses of positions in the latter memory randomly or according to a predetermined rule of selection so that the other memory (14) for each scanning cycle is up¬ dated only partly and in positions that are distributed over the area of the memory.2. A correlation follower according to claim 1, c h a r a c t e r¬ i s e d in that, the video correlator (3) is arranged to select the addresses to the positions of the memory for the updating so that of addresses generated in a certain sequence each p-th is selected where p is a prime number.3. A correlation follower according to claim 1, c h a r a c t e r- i s e d in that the video correlator (3) is arranged to read while updating each selected position in the other memory (14) , the contents stored in that memory and at the corresponding .IjlJREA tOMPI position of the first memory (12), to combine the contents of the said positions with one another and to state, in accordance with the criterion applying to each combination of contents, with which value the selected position in the other memory (14) is to be updated.BUROA? ,< wip | JONSSON R; LUDVIGSSON G; SAAB SCANIA AB; WARNSTAM L | JONSSON R; LUDVIGSSON G; WARNSTAM L |
WO-1979000261-A1 | 1,979,000,261 | WO | A1 | EN | 19,790,517 | 1,979 | 20,090,507 | new | C05D9 | null | C05D9 | C05D 9/00 | COMPOSITION AND PROCESS FOR A GRANULAR PLANT NUTRIENT | Granular, free-flowing, slow release plant nutrient compositions suitable for use in growth media are prepared by treating granules of a calcined clay, such as montmorillonite, attapulgite, sepiolite chlorite or vermiculite, with one or more solutions of salts of iron, boron, molybdenum, chloride, manganese, zinc, copper and sulphur. Optionally, the salt solutions may contain a sequestering agent. | APPLICATION FOR LETTERS PATENTFORNUTRIENT COMPOSITIONS,METHODS AND PROCESSESThe present invention relates to certain free flowing plant nutrient compositions containing calcined clay granules having various plant nutrients attached thereto, a method for their preparation and a process for their use. During recent years there has been a rapid increase in the use of growing and potting media (here- inafter called growth media ) for plants containing little or no natural mineral soil. Growth media are generally mixtures of an organic material such as peat or tree bark with inorganic granular materials such as sand, perlite, or exfoliated mica. They have desirable air relations for commercial plant growing operations and are usually relatively free of insects and diseases compared to many natural soils. Additionally, they are easier to handle and ship due to lightness. Since it is the soil minerals that supply the majority of minor nutrients, typically growth media are deficient or devoid of one or more of these nutrients . Minor plant nutrients, i.e., those elements used in -βUREΛϋ OMPI amounts ranging from several hundred parts per million to trace quantities, are commonly referred to as micro- nutrients. Micronutrients are iron, zinc, manganese, copper, boron, molybdenum and chlorine.One of the current ways of supplying micro¬ nutrients to growth media is to apply a shot gun mixture of these micronutrients in salt form. However, because these mixtures are of different particle sizes and densities, they tend to segregate, and thus, are not uniformly distributed in the growth media. Another method of supplying certain of these micronutrients is to apply them as their metal chelates. These chelates are in ready available form for plant uptake or foliar absorption. In general, they are used to cure an acute problem and are not effective for long term problems because leaching readily removes those chelates from the media. Thus, they must be applied repeatedly, making them expensive. Additionally, ionic micro¬ nutrients can not be supplied as chelates. Another alternative is to employ virtually insoluble microfrits which are widely accepted as slowly available sources of micronutrients. However, the rate of release of these nutrients is variable, non-predictable, and may be inadequate. Also, the density and fineness of these frits makes uniform incorporation into growth media difficult.Plant nutrient compositions suitable for providing plant micronutrients to growth media should possess certain characteristics which include (1) essentially uniform chemical and physical properties;(2). ability to be easily incorporated into the growth media; (.3) suitable means for micronutrient retention-•gυO l and release; (.4) favorable density and particle size so that they are compatible with the growth media, and (.5) a low risk of causing micronutrient imbalances, for example, too much manganese causes iron deficiency.An object of this invention is to provide plant nutrient compositions containing micronutrients which have essentially uniform chemical and physical properties, have a suitable means for micronutrient retention and release, have a low risk of providing micronutrient imbalances, are compatible with growth media and can be easily incorporated into such media.Another object of this invention is to pro¬ vide slow release plant nutrient compositions.Another object of this invention is to pro- vide plant nutrient compositions containing micro¬ nutrients and the macronutrient sulphur.The plant nutrient compositions of this invention include calcined clay granules as carriers having attached thereto micronutrients and the macro- nutrient sulphur. The importance of sulphur is that it is used by plants in amounts comparable to phosphorus and should be present in amounts to provide a nitrogen: sulphur ratio of about 12:1 in order to metabolize protein. Most high analysis fertilizers are nearly evoid of sulphur.Calcined clay granules are utilized in the practice of this invention. It is to be understood herein that the term calcined clay means that it has been heated at elevated temperatures to effect bonding among individual particles. In general the clay should be calcined at a sufficiently high temperature i.e., 500 C. to 750 C. to insure dimensional staBility wet or dry and should be capable of absorbing about 30 to 45% by weight of aqueous liquid and still maintain flowability of individual granules.It is desirable that such granules be largely composed of what is called three platelet or 2:1 layer silicate minerals. The most widely distributed 2:1 clay is montmorillonite which is an essential component of what is called bentonite. Similar clays are attapulgite, sepiolite, chlorite and vermiculite. All of these clays to some degree have a permanent negative charge by isomorphous substitution of a lower valence cation for aluminum in the middle (octahedral) layer or aluminum for silicon in the outer Ctetrahedral) layer. The result of these quirks of nature is structural negativity not influenced by pH.. For example, selected calcined clays have a permanent cation exchange capacity in the range of 15-25 milliequivalents per 100 grams.To be compatible with and allow even distribution throughout the commonly used growth media, which generally have a density of from about 0.3 to about 0.8 gm. cc and a particle size of from about 0.1 to 10 mm, the clay granules generally have a bulk density from about 0.4 to Q.8 grams per cc with a particle size from about 4 to about 50 mesh (U.S. standard seive) .The following micronutrients are attached to the calcined clay granules: iron, zinc, manganese, copper, molybdenum, boron and chlorine. The macro- nutrient sulphur is also attached. The micronutrients and macronutrient are present in a form suitable to nourish plants. Thus, they may be present in ionic form or combined as molecules, e.g., Fe +2, Fe+3, Zn+2, Mn +2, Cu+2, H2B03-1, HB03-2, B03-3, Ho04-2 , Cl-1, S04-2, FeS04, ZnSO. , FeCl- and ZnCl..The plant nutrient compositions of this invention exhibit plant nutrient composition character¬ istics which include having essentially uniform physical and chemical properties, having a suitable **-* means for nutrient retention and release, having a low risk of providing nutrient imbalances, being free flowing, having reduced dustiness, being compatible with growth media and being easily incorporated into growth media.5 The micronutrients and the macronutrient sulphur are present in the plant nutrient compositions of this invention in plant nutrient amounts, i.e., when such compositions are used in plant nourishing amounts, sufficient micronutrients and the macronutrient are 0 present to nourish plant growth. Nutrient amounts include, for example, in the case of iron an amount of from about 0.1 to about 5.0 weight percent, in the case of manganese an amount from about 0.05 to about 1.0 weight percent, in the case of zinc an amount from 5 about 0.02 to about 2.0 weight percent, in the case of copper an amount from about 0.05 to about 0.5 weight percent, in the case of sulphur an amount from about 1.0 to about 5.0 weight percent, in the case of boron an amount from about 0.02 to about 0.03 weight percent, 0 in the case of molybdenum an amount from about 0.0005 to about 0.0010 weight percent and in the case of chlorine an amount from about 0.1 to about 3.0 weight percent. All values are on an elemental basis, basedon the total weight of the plant nutrient composition.When the compositions of this invention contain cations they are attached to the negatively charged exchange sites until the charges are satisfied. Excess cations, anions and combined molecules, if present, are absorbed by physical forces and held on the internal and external surfaces of the granules. Usually, the ferrous ion, if present, oxidizes in part to ferric ion and this ion forms a coating on the granule which it is believed acts as a barrier to the free egress of the absorbed ions.To insure ease of incorporation and a more uniform dispersion throughout the growth media, the bulk density of tile compositions of this invention is generally in the range from about 0.5 to about 1.2, preferably from about 0.8 to about 1.0 grams per cc and the particle size of the composition is in the range from about 4 to about 50 mesh U.S. standard seive.The compositions of the present invention are prepared by a method which comprises mixing with the calcined clay granules under ambient conditions a solution or suspension containing the micronutrients and the macronutrient, sulphur. Advantageously, the solutions in highly concentrated form are sprayed on tumbling granules. Usually, the micronutrients and sulphur in their water soluble salt form are dissolved in water to form the solution or suspension to be applied to the clay granules. Often, because of-fϋ O incompatibilities, (e.g., salting out, reaction, pre¬ cipitation) more than one solution or suspension is employed. In an especially preferred embodiment, a first solution containing ferrous chloride, boric acid, ammonium molybdate or other suitable soluble, iron, boron, molybdenum or chloride salts is applied by spraying to the calcined clay granules. The con¬ centration is from about 25% to about 35% on a dis¬ solved solids basis. Next a second solution containing manganese sulfate, zinc sulfate and copper sulfate or other suitable manganese, zinc, copper or sulphur salts is applied by spraying to the calcined clay granules. By applying the micronutrients in this manner, interaction between iron and copper and salting out is prevented.Advantageously, a sequestering agent is contained in the solutions. Such sequestering agents include citric acid, tartaric acid, ethylene diamine tetra acetic acid, ethylene diamine di (o-hydroxy phenyl acetic acid), etc. in sequestering amounts, usually from about 0.1% to about 5% by weight based on the total weight of the product composition of this invention. When present in the plant nutrient composi¬ tions of this invention, the sequestering agents tend to accelerate the release of iron and other metallic ions.The process of using the plant nutrient compositions of this invention comprises applying the compositions to the growth media in plant nourishing amounts , i . e . , an amount sufficient to nourish plant growth. Typically such a plant nourishing amount is in the range of about 1 to 20 lb. per cubic yard of medium. The compositions are conveniently applied by mixing the correct quantity with the media.It is believed that when the plant nutrient compositions of this invention are incorporated into the growth media they will equilibrate with the solution bathing the roots and the media. The plant roots exchange protons and bicarbonates for the needed ions in solution which in turn exchange with the micro¬ nutrients on the clay granules to supply nutrients to complete the cycle. This is nature's method of sustain¬ ing the vegetation of the planet and will work equally well for any plant growing in a growth media.The invention is further illustrated by the following illustrative examples which are not in limitation of the invention. All parts and percentages are by weight unless otherwise indicated. EXAMPLE I1000 g. of 16 to 30 mesh calcined meta-bentonite clay granules were sprayed, while tumbling, as follows:1. With a first solution composed of 109 g. FeCl2< H20, 1.71 g. H3B03, and 0.02 g.(NH.) fiMo7O ..H„0 made to a total volume of 200 ml with deionized water.2. With a second solution composed of 23 g. MnS04. H O, 67 g. ZnS04.7H20, and 19 g. CuS04.5H20 made to a total volume of 200 ml with deionized water.The resulting product weighed 1524 g. and flowed freely. It was extracted in 1:1 HC1 and the elements converted to soluble form and analyzed by official methods of the Association of Agricultural Chemists. Chlorine was extracted in nitric acid and determined separately also by official methods.The product was found to contain the following micro¬ nutrients. Percents are by weight on an elemental basisFe - 2.61%Zn - 1.00%Mn - 0.52%Cu - 0.33%B - 0.02%Mo - 0.0005%Cl* - 2.64%The clay granules contributed 0.69% Fe. EXAMPLE II656 lb. of 16 to 30 mesh calcined attapulgite clay granules were sprayed while tumbling, as follows:First, with a solution composed of 117 lb. ferrous chloride solution (17.5% Fe) , 1.20 lb. boric acid (17.5% B) , 6 g. ammonium molybdate (54% Mo) , and 53.5 lb. water.Second, with a solution composed of 29 lb. zinc sulfate (.36% Zn) , 18.3 lb. manganese sulfate (27.3% Mn) , 11.8 lb. copper sulfate (25.4% Cu) , and 113.2 lb. water.The resulting product weighed 1000 lb. and flowed freely.Upon analysis by official methods the product was found to be:Fe - 2.90%Zn - 1.04%Mn - .50%Cu - .29%B - .02%Mo - .0007%S - 0.96%Cl — 2.58%The clay granules contributed 0.90% Fe. ASSESSMENT OF NUTRIENT AVAILABILITYExtractions10 g. of the composition of this invention made according to Example II were shaken 30 seconds in 250 ml IN ammonium acetate at pH 3.0. After filtering, the extract.was dried on a steam bath and redissolved in 1:1 HC1 for analysis by official methods.Results showed the following availability of nutrients :Fe - 1% Zn - 73%Mn - 82% Cu - 47% B - 90% Mo - 33%Cl and S were not determined.Similarly, another 10 gram sample was extracted ac¬ cording to official procedures using water and Na2EDTA. Results indicated that 100% of Cl, Mo, B and 80% of the S were recovered in the water and are available. 60% of the added Fe, 100% of the Zn, 98% of the Mn, and 70% of the Cu were recovered in the EDTA extract and are available.Leaching From Potting MixThe composition of Example II incorporated in a 1:1 peat-perlite at 5 lb. per cubic yard of mix was equilibrated'gυREΛc OMPI at field capacity for 24 hours, then leached with 1/2- inch increments of water daily for 5 days. The extract was composited and showed:Nutrient % leached from mixFe 0%Zn 16%Mn 27%Cu 2%B 64%Mo 98%PlantsMarigolds were grown for 3 months in an untreated peat-perlite mix and a mix treated with 2.5 lb. of the composition of this invention per cubic yard. Analysis of the plants indicated the following concentrations of elements:Concentration in ppm (means of 4 replicates) Fe Zn Mn Cu BTreated 158 137 170 22 39Untreated 150 76 100 12 22Six genera of foliage plants (Paim, Aralia, Aphelandra, Spathiphyllum, Peperomia, and Calathea) were grown for 15 weeks in an untreated 1:1 peat-pine bark medium and in a treated one using the composition of this invention at a rate of 5.0 lb. per cubic yard. Each treatment was replicated six times on each plant and the mean values over all plants is as follows :Concentration in ppm (means of 36 plants)Fe Zn Mn Cu BTreated 60 95 176 10 47Untreated 55 51 90 34-BUREΛIOMPI y> WIPO Λ | WHAT IS CLAIMED:1. A granular, free-flowing plant nutrient composition suitable for use in growth media exhibiting plant nutrient composition characteristics including having essentially uniform chemical and physical properties , a bulk density of from about 0.8 to about 1.0 gram per cc and a particle size of from about 4 to about 50 mesh consisting essentially of calcined clay granules having attached thereto in nutrient amounts the nutrients iron, zinc, molybdenum, manganese, copper, boron, chlorine and sulphur.2. A composition according to Claim 1 wherein said clay is selected from among montmorillonite, attapulgite, sepiolite, chlorite, and vermiculite.3. A composition according to Claim 2 wherein said clay is montmorillonite.4. A process for preparing the composition of Claim 1 which comprises applying to the calcined clay granules a first solution containing soluble salts to provide the nutrients iron, boron, molybdenum and chlorine and thereafter applying to said granules a second solution containing soluble salts to provide the nutrients manganese, sulphur, zinc and copper.5. A process according to Claim 4 wherein the salts in the first solution are FeCl„, H^B0_ and CNH.),Mo7 O , and in the second solution are MnSO . , ZnS04, and CuS04. 6. A process according to Claim 5 wherein the first solution additionally contains in a sequester¬ ing amount a sequestering agent selected from among citric acid, tartaric acid, ethylene diamine tetra 5 acetic acid, and ethylene diamine di (o-hydroxy phenyl acetic acid) .7. A process for treating growth media to provide plant nutrients which comprises applying to said media in plant nourishing amounts the composition of Claim 1.8. A granular, free-flowing plant nutrient composition suitable for use in growth media exhibiting plant nutrient composition characteristics including having essentially uniform chemical and physical c properties, the nutrients being slowly releasable, having a bulk density of from about 0.8 to about 1.0 gm/cc and a particle size of from about 4 to about 50 mesh U.S. standard seive consisting essentially of granules of calcined montmorillonite clay having10 attached thereto about 1% by weight of sulphur, about 0.02% by weight of boron, about 2.60% by weight of chlorine, about 0.3% by weight of copper, about 0.50% by weight of manganese, about 0.0006% by weight of molybdenum, about 1.0% by weight of zinc and about 5 2.0% by weight of iron. | MALLINCKRODT INC | BARDSLEY C |
WO-1979000262-A1 | 1,979,000,262 | WO | A1 | EN | 19,790,517 | 1,979 | 20,090,507 | new | C02C1 | C02C5, C02C1 | C02F3 | C02F 3/12J, C02F 3/20E3, C02F 3/30B, C02F 3/30D | FLOW CONTROL APPARATUS AND PROCESS FOR AN OXIDATION DITCH | In closed circuit aeration liquid sewage treatment systems, a need exists for a device and method for preventing back-mixing of aerated liquid into the intake of the aerator, and for aerating the sewage efficiently at least once per circuit-flow cycle by bringing the air and all of the liquid into singly occurring contact. The invention comprises a barrier (22), which divides an aeration ditch (10) into an intake channel (75) and a discharge channel (77), and at least one submerged aerating pump (28) which pumps sewage in circuit from the intake channel to the discharge while it is being aerated by a supply of compressed air. Back-mixing of aerated liquid to the intake channel is thereby completely prevented, and the oxygen transfer efficiency to the liquid is thereby increased. By independently controlling the submerged pump speed and the amount of compressed air, the aerobic/ anaerobic ratio can be varied through seasonal temperature changes. | DescriptionFlow-Control Apparatus and Process For An Oxidation DitchTechnical Field This invention relates to gas-liquid contacting devices and the use of such devices in liquid treatment systems . The invention additionally relates to oxygen- absorption processes requiring repeated and prolonged air-liquid contact in sequential stages . The invention especially relates to methods and apparatus for aeration purrping of wastewater such as sewage within aerobic purification systems of the looped channel type , such as oxidation ditches . Background Art This application is a continuation-in-part of U.S. Serial No. 649,995, filed January 19, 1976, entitled FLOW CONTROL APPARATUS AND METHOD FOR AEROBIC SEWAGE TREATMENT of John Hager Reid, which is now pending. Many liquid treatment processes, commonly termed aerobic processes, supply bacteria and other bio-organisms with dissolved oxygen for treating aqueous wastes such as municipal sewage, cannery wastes, dairy wastes, meat-processing wastes, and the like. Such aerobic processes are commonly accelerated by concentrating and activating the bio-organisms, termed bio-mass or activated sludge, and returning this sludge to be mixed with incoming wastewater which supplies food for the organisms. Activated-sludge processes for aerobic treatment of wastewaters have followed two main lines of development: vertical-flow aeration basins and. circuit-flow oxidation ditches. Vertical-flow aeration basins are typically aerated on a large scale with one or more impeller-type aerators which are vertically mounted and disposed at the surface of the liquid, as discussed in Water & Wastes Engineering, September, 1975, pages 76-79, using an aerator such as is described in U.S. Patent No. 3,479,017 and producing a uniform dissolved- oxygen (D.O.) content of 2.0 mg/liter. Such impeller aerators are frequently mounted within and at the upper open end of a draft tube extending partially or entirely to the bottom of the basin so that the aerator can more efficiently pump liquid from the bottom of the basin, having a depth up to 40 feet, and disperse it over the surface of the basin, there¬ by improving vertical circulation over a wide area. When fitted with a gear reducer to spin a nine-foot diameter impeller at low speeds, oxygen transfer efficiencies of 3.5 pounds 02/hp/hour have been approached.In an early oxidation-ditch process, Dutch Patent 87,500 discloses horizontally mounted rotors having brush surfaces for adding oxygen to sewage and causing the sewage to flow for a period of time in a closed-loop circuit within an ovally laid-out ditch, the liquid then being clarified by settling and excess sludge being removed. In subsequent develop¬ ments directed to adding oxygen to sewage and inducing circuit-flow circulation in oxidation ditches, U.S. Patent No. 3,336,016 discloses an S-shaped duct, U.S. Patent No. 3,510,110 the combination of a longitudinal partition and a vertically disposed surface aerator which is adjacent thereto, and U.S. PatentOM No. 3,846,292 a plurality of subsurface ejector aerators,Finally, U.S. Patent No. 3,900,394 discloses a sewage purification process, to be carried out in a circuit-flow oxidation ditch having an impeller-type aerator at one or both ends, which comprises sequential aeration of incoming sewage, aerobic decomposition and depletion of its oxygen content, introduction of additional sewage to the oxygen-starved bacteria, and, simultaneously, aerobic decomposition and denitrifica- tion of the additional sewage as the bacteria break down its nitrates.A circuit-flow oxidation ditch is a complete mix system operating in plug-type flow. It can be designed to operate with recycled sludge on a food-to-micro- organism ratio (F/M) varying over a possible range of 0.01 to 5.0, depending upon space, cost, and process design requirements. If operating at a low F/M ratio of 0.01-0.2, it is an extended aeration system, produc¬ ing small quantities of sludge. If operating at a medium F/M ratio of 0.2-0.5, it is a conventional system. If operating at a high F/M ratio of 0.5- 2.5, it is a high-rate activated sludge system, producing large quantities of sludge. Moreover, it can even be operated as an activated lagoon with no recycled sludge, having F/M ratios above 2.5. An oxidation ditch may also shift through a wide F/M range, representing all three of these systems, as it begins operation as a high-rate activated sludge system, with no built-up sludge, and gradually builds up its recycled sludge to a mixed liquor suspended solids (MLSS) content of 3,000 ιrg/1 where extended aeration can generally be considered to begin.OMPI There are now three main types of aeration apparatuses in use within circuit flow oxidation ditches of varied depth and variety of layouts, such as an oval- shaped racetrack and a plurality of looped or end- less channels. These are:1) horizontally shafted surface aerators,2) vertically shafted surface aerators, and3) eddy-jet type subsurface aerators. Horizontally shafted surface aerators are of two general types:1) brush, cage, or rotor aerators, such as those manufactured by Lakeside Equipment Corporation, Bartlett, Illinois, andPassavant Corporation, Birmingham, Alabama, which have a maximum power input of about 50-60 horsepower, and2) aeration discs, such as those manufactured by Envirex, Incorporated, Waukesha, Wisconsin. Each type transfers 2-3.25 pounds of oxygen per shaft horsepower per hour from air to the mixed liquor. Slow-speed surface aerators are used in looped channel designs known as Carrousel, developed by Dwars, Heederik Verhey, of A ersfoort, the Nether- lands, as an improved form of the basic oxidation ditch. Each aerator is mounted vertically in the rounded end of a deep channel having a central partition that is positioned close to the aerator to create within the channel a uniform turbulent flow that is both longitudinal and spiral in nature. Such a surface aerator transfers 3-4 pounds of 02/hp/ hr from air to mixed liquor.f O -5-An eddy-jet system is known as deep channel jet aeration, sold by Penberthy Division of Houdaille Industries, in which air jet headers are mounted near the floor of a 20-foot deep channel to provide propulsion and high-efficiency aeration at an oxygen transfer efficiency of 3-4 pounds O^/hp/hr.Greater transfer efficiencies are needed in order to conserve energy and minimize the cost and number of aeration devices which are needed in' an oxidation ditch.When oxygenating water with air, the necessary driving force increases non-linearly as the dissolved- oxygen content of the water increases. Frequency of liquid-gas contact is consequently quite important from an efficiency viewpoint even though mixing of liquid parcels having various contents of dissolved oxygen soon produces a uniform average oxygen content. More specifically, if a portion of the liquid, initially having zero dissolved oxygen, contacts a gas such as air several times, it at first absorbs oxygen very readily but increasingly slowly thereafter. Vertical circulation causes some aerated water to be directly back-mixed into the intake of the aerator. Thus, energy is wasted by attempting to re-aerate water that has already been aerated. A need consequently exists for a flow control method and means for minimizing vertical circulation and turbulent mixing and for bringing liquid and gas into singly occurring contact.These prior-art systems using surface aerators are generally plagued with aerosol spray and misting, freezing problems in cold weather, dependence of mixing and power consumption upon oxygen demand, excessive noise, dependence of power consumption upon liquid-level variations, and the need for floating aerators to compensate for variations in the liquid level. The eddy-jet system requires excessively high blower pressure to introduce air at the bottom of a deep channel and requires the operation and maintenance of a plurality of circulation pumps to force or inject mixed liquor through the submerged jets.These problems could be minimized or obviated by using a submerged turbine to provide subsurface aeration, but there is no means available for mounting a submerged turbine within an oxidation ditch so that plug-type flow can be generated, channel velocity can be accurately controlled, back mixing can be avoided, and complete mix can be attained.In order to facilitate mass transfer of oxygen from air bubbles into the mixed liquor and thence into the microorganisms, it is also desirable to avoid the prior-art environment of relative quiesence and to provide instead a means for shearing all of the bacterial floe within an oxidation ditch into smaller particles, such as by forcing all of the mixed liquor past a shear-type pump means or a bubble-splitting and mixing means, at least once per circuit- flow cycle. However, no means exists in the prior art for requiring all of the mixed liquor to pass through either such means.In addition, bacterial activity can be enhanced by increasing the dissolved-oxygen content of the mixed liquor at least once per circuit-flow cycle,OM such as by generating pressures upon the air bubble-mixed liquor mixture that are greater than the hydraulic pressure within the channel of the oxidation ditch. Again, no such practical means exists for an oxidation ditch.Disclosure of InventionIt is therefore an object of this invention to provide a means for mounting a submerged turbine within an oxidation ditch. It is also an object to provide a means for preventing vertical circulation and back mixing of aerated liquid from the discharge of a submerged turbine within an oxidation ditch to the intake thereof. It is further an object to provide a means for completely mixing return sludge, wastewater feed, and air at the intake of a submerged turbine within an oxidation ditch.It is still further an object to provide a means for generating plug-type flow within an oxidation ditch, from the discharge of a submerged turbine mounted therewithin to the intake thereof, without back ixing of aerated liquid.It is likewise an object to provide a means for accurately controlling flow velocity within the channel of an oxidation ditch, from the discharge of a submerged turbine mounted within the ditch to the intake thereof, without backmixing of aerated liquid. It is another object to provide a means for generating pressures upon liquids and air being pumped by said submerged turbine that are greater than the hydraulic pressure at the bottom of the channel in the oxidation ditch.It is still another object to provide a means for maintaining a generated pressure upon a liquid¬ air mixture, for a selected distance and/or during a selected time interval, that is greater than the hydraulic pressure at the bottom of the channel in the oxidation ditch.It is an additional object to provide a means for maintaining, throughout the entire aerobic portion of the oxidation ditch, a generated pressure upon a liquid-air mixture that is greater than the hydraulic pressure at the bottom of the channel in the oxidation ditch. it is a still additional object to provide a means for continually forcing, at least once per cycle, all of the mixed liquor within an oxidation ditch past a shear means for shearing bacterial floe into smaller particles. it is moreover an object to provide variable velocity control, so that the ditch velocity can be controlled over a wide range, and independently variable aeration control, so that the dissolved-oxygen content of discharged liquor can also be varied over a wide range, independently of the flow rate in the oxidation ditch.It is furthermore an object to provide a means for controlling the lengths of the aerobic and anoxic zones within the channel of an oxidation ditch in order to adjust and control the relative populations of heterotrophic aerobic and heterotrophic facultative (denitrifying)OM bacteria and autotrophic (nitrifying) bacteria in order that the operation of the ditch will respond to seasonal temperature changes. In accordance with these objectives and the principles of this invention, 'apparatuses and methods are herein described that provide a submerged turbine, a mounting means for the turbine, a feed means for compressed air, a feed means for return sludge, a feed means for raw wastewater, a barrier means for: (a) forcing all mixed liquor through the intake of the submerged turbine on the upstream side of the barrier means, (b) prevent¬ ing back mixing and vertical circulation of aerated liquid' to the turbine intake, and (c) accumulating all aerated liquid on the downstream side of the barrier means, and a discharge duct from the turbine to the down¬ stream side of the barrier means which passes beneath the barrier means, preferably at a greater depth than the floor of the oxidation ditch channel. This discharge duct comprises a curved discharge section connected to the turbine, a first straight section connected to the curved discharge section, an updraft section connected to the straight section, a second straight section connected to the updraft section, and a terminal duct connected to the second straight section and disposed on the downstream side of the barrier means. •The discharge duct may contain throughout any selected portion of its length a bubble- splitting and mixing means, such as the structures described in U.S. Patents 3,782,694; 3,635,444; 3,643,927; 3,664,638; 3,751,009; 3,733,057; 3,643,927; and 3,7^24,300, or an interfacial surface generator, such as the -5 structures described in U.S. Patents 3,358,749; 3,394,924; and 3,406,947. The discharge duct may also be extended in the direction of flow for a sufficient distance that subs¬ tantially all of the aerobic activity of the-10 ditch occurs within the discharge duct and under a selected hydraulic pressure that is greater than the pressure corresponding to the depth of the channel.The term, oxidation ditch, is currently15 used for relatively shallow oval-shaped basins in which mixed liquor is continuously circulated by horizontally mounted surface aerators, such as cage rotors and disc rotors, and other terms, such as looped channel and endless20 channel, are currently used for deep basins in which the mixed liquor moves back and forth through a plurality of side-by-side channel portions which have adjoining walls and semi- cylindrical ends providing connections between25 adjacent channel portions. However, the term, oxidation ditch, is employed herein as a general term encompassing both shallow and deep basins, whether circular, oval, or looped in any endless configuration.'30 in such a closed-circuit oxidation ditch, this invention comprises at least one flow- control apparatus which provides repetitive aerobic treatment to all of the mixed liquor within the channel of the oxidation ditch. The-βUR OM flow-control apparatus comprises a barrier which is sealably attached to the sides of the oxidation ditch and divides the mixed liquor into upstream liquor within an intake channel and downstream liquor within a discharge channel. The flow-control apparatus also comprises at least one submerged turbine, which is disposed to receive the upstream liquor and pump it downwardly. Each submerged turbine is attached to the bottom and/or sides of the oxidation ditch and/or the barrier and comprises a motor, a speed-reduction means, a. turbine shaft, turbine blades, at least one air sparge ring, and a downdraft tube surrounding the blades.A discharge duct is connected to the down¬ draft tube, leads downwardly to any desired depth, curves in a downstream direction, and leads upwardly to a discharge point within the discharge channel. Preferably, the discharge duct reaches a greater depth than that of either the intake channel or the discharge channel.The flow-control apparatus of this invention provides separate control of mixed-liquor flow velocity and of mixed-liquor aeration. This operating characteristic is partly possible because the pumping capacity of the turbine is decreased only to a slight extent by varying the amount of air that is introduced to the sparge ring and is increased to a significant extent by introduction of compressed air to any of the sections of the discharge duct. By selectively shifting the proportions of air introduced to the sparge ring and to the discharge duct, the flow rate can be varied by at least 50 percent, and by varying: a) operation of the turbines singly or in parallel, b) the speeds of the turbines, c) the total amount of air, and d) the propor¬ tion of air between the sparge ring and the discharge duct, it is readily possible to vary the flow rate over a range of from 0.5 ft/sec to at least 3.0 ft/sec while maintaining a desired dissolved-oxygen (D.Q.) output or to vary the D.O. output while maintaining a desired flow rate or to vary both properties in any desired combination, while operating all turbines at a constant speed.One consequence of this capability is that the lengths of the aerobic and anoxic zones within the oxidation ditch can be varied as desired, particularly in accordance with seasonal temperature changes. If the flow rate is maintained constant and the D.O. level is decreased, for example, the aerobic zone is shorter and the anoxic zone is longer so that the mixed liquor is subject to aerobic and anoxic conditions for correspondingly timed aerobic/anoxic ratios. If the flow rate is increased, for example, while the D.O. level remains constant, the aerobic zone is maintained for the same time interval but throughout a greater distance so that a smaller remaining distance is in the anoxic state. Thus, the timed aerobic/anoxic ratio is increased. Brief Description of DrawingsThe accompanying drawings enable the invention to be better understood.Figure 1 is a plan view of an oval-shaped oxidation ditch having an island and a double- turbine flow-control apparatus of this invention, disposed athwart one straight channel.Figure 2 is a sectional elevation, taken approximately in mid-channel and looking in the direction of the arrows 2-2 in Figure 1.Figure 3 is a cross-sectional elevation of the oxidation ditch shown in Figure 1, looking in the direction of the arrows 3-3 in Figure 1, toward the turbines and the barrier.Figure 4 is a plan view of a portion of an oxidation ditch, similar to the ditch of Figure 1, having a triple-turbine flow-control apparatus which is disposed athwart a straight channel.Best Mode for Carrying Out the Invention The flow-control apparatus 20 of this invention, as shown in Figures 1-3, is installed athwart a channel of an oxidation ditch 10 having an island 11, inner edge 12, and outer edge 14. Such a channel typically has a floor or bottom 15, sloping inner side 16, and sloping outer side 18.The flow-control apparatus 20 comprises a barrier 22, a pair of turbines 28 and 30, which are preferably low-speed, vertically mounted, electrically driven turbines, and respective discharge ducts 29 and 60. The barrier 22 comprises a top 23, an upstream side 24, a dσwnstream side 25, and a pair of handrails 26. Barrier 22 is suitably an earthern ber which is covered on its exposed surfaces with a layer of gunnite.Turbine 30, as clearly seen in Figure 2, comprises a - motor 31, a speed reducer 32 which is connected there¬ to, a vertically disposed shaft 33, propeller blades 35 at the bottαn end of shaft 33, a coaxially disposed slap ring 36, a stabilizer cylinder 37 into which the slap ring 36 loosely fits, an intake funnel 38 which 0 is disposed above the blades 35, and a dσ ndraft tube 39 which surrounds the blades 35, slap ring 36, and stabilizer cylinder 37.• The turbines 28 and 30 are connected by a walkway 43 and a pair of handrails 41. Turbine 30 is mounted on 5 columns 42 and is equipped with vertically disposed diffusers 47 and a horizontally disposed baffle stabilizer ring 45. An air sparge ring 53, with air openings facing the turbine blades 35, is mounted beneath the turbine blades and is connected to an air delivery line 52. Air delivery 0 line 51 is connected to turbine 28.As shown in Figure 1, a raw feed (wastewater) line 56 is connected to an anoxic delivery line 57 and to turbine delivery line 58 which supplies both turbines 28, 30. As seen in Figure 2, wastewater line 58 is controlled by a 5 valve 59.Return sludge line 54 likewise supplies both turbines 28, 30. As seen in Figure 2, delivery line 54 to turbine 30 is controlled by valve 55. As is known in the art, a portion of the mixed liquor flows continuously into clarifier 83 from 0 which streams 85 of clarified liquor and of settled sludge are discharged. All of the clarified liquor and a portion of the sludge are sent to disposal facilities, and the remainder of the sludge flews through return sludge line 54 to turbines 28, 30. Barrier 22 is also sealably attached to sides 16 and 18 and floor 15 of the channel in which it is disposed and which it divides into intake channel 75 and discharge channel 77. As seen in Figure 2, the mixed liquor in this channel may vary over range 44 in height, from high liquor level 48 to low liquor level 49, so there is always at least a minimum submergence depth 46 for intake funnel 38, a depth that is necessary to prevent cavitation. Discharge duct 60 for turbine 30 is connected to downdraft tube 39, curves down¬ wardly and forwardly beneath barrier 22 and curves upwardly again to empty into discharge channel 77 where it converges slightly with discharge duct 29. Discharge duct 60 comprises curved discharge section 61 which is connected to downdraft tube 39, first straight section 63 which is connected to section 61 and is horizontally disposed, curved updraft section 65 which is connected to straight section 63, second straight section 67 which is connected to section 65, and terminal duct 69 which is connected to section 67 and is curved downwardly so that discharge of aerated mixed liquor and air is essentially parallel to the floor 15 of the discharge channel 77 which is consequently in a constantly turbulent state. Discharge duct 60, which is usually exactly like discharge duct 29, may readily be lengthened to any desired extent by inserting a plurality of straight sections 63 and/or by decreasing the angle of curvature of sections 65, 69 and inserting a plurality of straight sections 67. Moreover, the efficiency of oxygen-to- liquor transfer may be enhanced, particularly as the bacteria absorb the dissolved oxygen,5. by installing a plurality of bubble-splitting devices in the straight sections 63, 67 so that fresh interfacial surfaces are being continuously and rapidly generated, the air is prevented from coalescing into10 large bubbles and is instead split into small bubbles, and the liquid films surrounding individual bacteria and bacterial floes are thinned, whereby oxygen transfer from the liquor into the bacteria is enhanced. /Additional15 compressed air may be delivered to the discharge ducts 29 and 60 as illustrated for duct 60 in Figure 2 wherein auxiliary air delivery line 71, controlled by valve 72, delivers air to sparge tube 76 in first straight20 section 63 and auxiliary air delivery line 73, controlled by valve 74, delivers air to sparge tube 78 in second straight section 67. By selectively adjusting the valves (not shown in the drawings) for lines 51 and25 52 and the valves 72 and 74, the flow rate through the discharge ducts 29 and 60 and the aeration of the mixed liquor may be selectively controlled, thereby changing the length of aerobic zone 79 and consequently30 the timed aerobic/anoxic ratio. This procedure is useful in response to changes in tempera¬ ture, pH, BOD, and nitrogen load. The flow-control apparatus of this invention may be of any desired size and may have any number of turbines in side-by-side relationship, as illustrated in Figure 4 for a triple-turbine installation. In a straight channel, having sizes 109 and floor 101, of oxidation ditch 100, the sides 109 become farther apart and steeper to define the much broader floor of an intake channel 105 which is separated from a discharge channel-107 by flow-control apparatus 90, comprising barrier 91, turbines 97, and discharge ducts 96. Barrier 91 ccmprises top 93, sides 95, and downstream bottom edge 94. Discharge channel 107 has sides 113 which gradually converge and become less steeply sloped to define a channel floor 101 of normal channel width. A clarifier 99, similar to clarifier 83 in Figure 1, receives a continuous flow of mixed liquor and discharges streams (not shown in the drawings) of settled sludge and clarified liquor.The submerged turbine which is preferred for use in the flow-control apparatus of this invention is an axial-flow Serial DAT aerator which is manufactured by Mixing Equipment Company, Inc. , Rochester, New York, equipped with a down-flow, high-efficiency impeller and a sparge ring which is mounted imnediately below the iitpeller, both being surrounded by a vertically disposed and relatively short draft tube. Such a submerged turbine is preferably mounted within the intake channel at a selected distance below its surface at lew water level but may satisfactorily be mounted within the barrier itself, in the island, or in the outer side area, provided that the intake of the turbine is always in flow communication with the intake channel and exposed to sufficient intake head.A conventional up-flow type of submerged turbine, having its impeller at the end of a terminal duct 69, is also suitable, but this type is preferably mounted in the discharge channel with its intake connected to the terminus of the discharge duct, so that it pulls (rather than pushes) the mixed liquor through the discharge duct from the intake channel to the discharge channel. A sparge means may be located in the downdraft tube (within the intake channel) and/or at another place in the discharge duct, such as in the first straight section and/or immediately below the impeller.Another pulling type of aerator is a surface aerator which can be located on the 'top of an updraft tube which is connected to the terminus of the discharge duct. The surface aerator is preferably floatingly supported within the discharge channel. A primary sparge means may also be located within the discharge duct to supply primary aeration.Any of these devices is a satisfactory pump means for moving the mixed liquor through the discharge ducts 29, 60, 97 along the flow path which each interconnected pump means and discharge duct provides, in combination, between the intake channel 75, 10S and the discharge channel 77, 107. Moreover, a down-flow submerged turbine, at the inlet end of the discharge duct, may be combined with either an up-flow submerged turbine or a surface aerator at the outlet end thereof, and a sparge means can additionally be mounted within the discharge duct, so that if air is introduced within either or both turbines, there will be as many as three or even four points of aeration. The advantage of such combinations is that the speed of reaction of the micro-organisms under pressure is utilized, whereby the aerobic portion of the ditch may be greatly shortened.The aeration means for introducing air to the mixed liquor being pumped from the intake channel to the discharge channel comprises a source of compressed air, a sparge means for producing air bubbles, and a delivery means for moving the compressed air from the source thereof, such as a blower or air compressor, to the sparge means.The sparge means shown beneath the impeller or turbine blades in Figure 2 consists of a primary sparge ring 53a and a secondary sparge ring 53b, both being fed by delivery lines 52 with separate valves (not shown in the drawings) for each sparge ring 53a, 53b. Each ring has five- radially aligned sparging fingers which are angularly displaced (i.e., offset) so that ima and secondary fingers are not in vertical alignment. Under low to moderate BOD loads, the sparge means 53a, 53b is operated by using the upper or primary ring 53a only. Under heavy BOD loads, both rings 53a, 53b are preferably utilized.When supplementary air or industrial oxygen is desired, as when BOD loads are very heavy, or when it is desirable to substitute discharge duct aeration for turbine aeration because of flow rate considerations, sparge tubes 76, 78 in first straight section 63 and in curved updraft section 65, respectively, are utilized by adjusting valves 72, 74 which selectively admit compressed air (not shown in the drawings) into auxiliary air delivery lines 71, 73 and thence into sparge tubes 76, 78. The compressed air, liberated as bubbles, is swept along through the discharge ducts 29, 60 to fo__m a mixture of relatively low density so that the velocity of upwardly translational movement through sections 63, 65, 67 and duct 69 is markedly increased by an air-lift pumping effect acting in addition to the purrping effect of the sxbmerged turbine propeller.The sparge tubes 76, 78 and their respective air delivery lines 71, 73 are removably mounted within respective casing pipes 66, 68 which are sealably attached to discharge duct 60, as shown in Figure 2, as by welding. Air delivery lines 71, 73 are preferably straight pipes, and sparge tubes 76, 78 may be trans¬ versely disposed within discharge duct 60. Mixed liquor rises approximately to level 49, as in the channels 75, 77 of the oxidation ditch 10, within the annular spaces between the casings 66, 68 and the air delivery lines 71, 73. If one of the sparge tubes 76, 78 ever becomes clogged or requires maintenance, aOM union at the top of its delivery line can be opened so that the assembly can be lifted out of its casing for cleaning the sparge tube.As a means of conserving power consumption by the air compressors, each discharge duct 29, 60 may be W-shaped by connecting an additional recurved duct to duct 69, followed by a third straight section, another curved section, a fourth straight section at the lowest depth, still another curved section, a fifth straight section, and a final recurved section as the terminus in the discharge channel 77, just above floor 15. Preferably, barrier 22 is widened sufficiently so that top 23 extends above present duct 69 at the center or hump of the W , and air delivery lines, like lines 71, 73 but much shorter, terminate in sparge tubes like sparge tubes 76, 78 within duct 69, being removably mounted within casings similar to casings 76, 78.Power is conserved because less pressure is needed to force compressed air to the center hump of the W . The additional distance under pressure also enables the bacterial propulation to utilize dissolved oxygen for a longer time while enabling a secondary supply of oxygen to be transferred from the compressed air to the mixed liquor.In Figure 1, aerobic zone 86 extends from the turbines 28, 30 to a short distance, such as 50-100 feet, downstream therefrom. This relatively short-length aerobic zone represents overall oxygen-starved process conditions, probably with relatively high F/M values in the range of 0.5-0.7.Extension 87, around the bend, represents an additional length of aerobic activity in the channel of the oxidation ditch 10. The combined distance of zone 86 + zone 87 indicates a reasonable amount of dissolved oxygen in combination with lower F/M values in the range of 0.2-0.5. The remainder of the channel is at an anoxic level of about 0.1 mg/1 or less of dissolved oxygen. This combined distance, divided by the remainder of the distance along the channel, produces a timed aerobic/anoxic ratio that is heavily biased toward denitrifying.Extension 88, downstream in the opposite side of the ditch 10, represents still additional aerobic activity. The combined distance of zone 86 + zone 87 + zone 88 indicates optimum quantities of dissolved oxygen are being introduced into the flow path for the mixed liquor. This combined distance, divided by the remainder of the distance along the channel to the turbines 28, 30, gives a timed aerobic/ anoxic ratio that is generally ideal for combined nitrification and denitrification.Moreover, when the incoming wastewater feed is added via line 57, just above the floor 15 of the channel in the return bend, organic food sources are maximized for any heterotrophic facultative denitrifying bacteria that are present in the circulating mixed liquor. In addition, any nitrate oxygen that/-BUR OM is available in the circulating mixed liquor for carbonaceous BOD reduction is utilized as fully as possible. ' More importantly, any nitrate oxygen that is available in the circulating mixed liquor is utilizable for oxidation of any hydrogen sulfide that is present in the feed waste such as an anaerobic lagoon effluent. Such utilization is performed by certain denitrifying bacteria that are present in the anoxic environment of the return bend. These bacteria utilize nitrate oxygen as their oxygen source and hydrogen sulfide as their food or energy source. By such utilization, hydrogen sulfide in the wastewater feed from the anaerobic lagoon is used to maximize denitrification and to minimize consumption of free dissolved oxygen for chemical and biological oxida¬ tion of hydrogen sulfide, thereby enabling free dissolved oxygen to be used to a maximum extent for biological BOD removal and nitrification.Locating the inlet pipe or an inlet flow diffuser or distribution pipe just above or along the floor 15 of the return bend, where turbulence naturally occurs, enhances opportunities for hydrogen sulfide to mix with the mixed liquor and minimizes its -> likelihood of escaping to the atmosphere. By inspection of Figure 2, the high water level 48 differs from the low water level 49 by height 44, and the lower water level 48 is above the impeller 35 by submergence depth 46 which is the minimum under which the turbines 28, 30 can operate without cavitation.In the oxidation ditch of this invention, the barrier 22, 91 does not function as a dam as might be supposed, but instead is used to control and direct the pumping action and pumping capabity of the submerged turbines 28, 30, 97 so that they create the desired velocity of flow within the channel of the oxidation ditch by enabling pumped mixed liquor to be accumulated in one portion (i.e., the discharge channel 77, 107) of the channel of the ditch and thereby to build up as much head as necessary for pumping the mixed liquor as far and as rapidly as desired.The barrier 22, 91 also completely pre¬ vents backmixing of aerated mixed liquor, thereb :(1) increasing the log mean driving force across the intakes and discharges of the submerged turbines 28, 30, 96 and discharge ducts 29, 60, 97, thereby decreasing the energy required for dissolving a given quantity of oxygen in the mixed liquor and increasing the oxygen transfer efficiency and(2) preventing short-circuiting of the mixed liquor with resultant stagnant areas in other parts of the channel.From an energy standpoint, substantially no input power is used for pumping against a static lift. Instead, substantially all input power is used for overcoming dynamicOMP losses caused by: 1) hydraulic friction' created by circuit flow past the walls 16, 18 and floor 15 of the channel of the ditch 10; 2) hydraulic turbulence in the channel bends.; and 3) hydraulic friction created by the sparge rings 53a, 53b, curved sections 61, 65, 69 and straight sections 53, 67 of the discharge ducts 29, 60.The mixed liquor is also believed to be pushed or propelled only part of the distance around the channel of the oxidation ditch and is then pulled the remaining distance to the intakes of the submerged turbines 28, 30, 97. The downdraft submerged turbine aerator offers the following process control advantages for use in the oxidation ditch process for treatment of wastewater: independent control of oxygen supply and mixing; easier control of power consumption to match oxygen demand; no aerosol spray and minimizing of misting; no freezing problems during cold weather . operation as typically occurs with rotor aerators, brush aerators, disk aerators, and other surface aerators presently used in oxidation ditches; minimal noise; minimal effect of liquid level variations upon power consumption; and easy compensation for variation of liquid level in the oxidation ditch without the need for floating aerators. The invention may be more thoroughly understood by study of the following examples, with reference to the drawings. Example IAn oxidation ditch as shown in Figures 1-3 was designed and constructed to treat waste¬ water effluent from an anaerobic lagoon used for pretreatment and flow equalization of raw wastewater produced by a poultry processing plant. This anaerobic effluent was anticipated to have the following characteristics:Biochemical oxygen demand, BOD(5)= 800 mg/1 Total suspended solids, TSS = 304 Ammonia nitrogen = 40 mg/1 Total Kjeldahl nitrogen, TKN = 62 mg/1 . pH = 6.4 Total phosphorus = 6-20mg/l The average daily flow of anaerobic lagoon effluent was anticipated to be 221,000 gallons per day (0.221 million gallons per day - MGD) , 7 days per week, 24 hours per day. The maximum average BOD(5) loading into the oxidation ditch was calculated as follows (mg/1 = #/million #) : (0.221 MGD) (8.34 #/gal.) (800 mg/1) = 1475 #BOD(5)/day. The maximum average TKN loading into the oxidation ditch was calculated as follows: (0.221) (8.34) (62 mg/1) = 114#/day The maximum oxygen demand at process or field conditions for an extended aeration process operated for maximum degree of nitrification was calculated as follows, assuming a design conversion factor of 1.4 # oxygen/#BOD(5) + 4.5# oxygen/#TKN applied: 1.4(1,475) + 4.5(114) = 2,578# oxygen/day.OMP - The oxygen required at standard conditions(20°C, one atmosphere, zero dissolved oxygen) , assuming a design conversion factor from process to standard of 1.6, was calculated as follows: 1.6 x 2,578 = 4,125# oxygen/day;4,125# oxygen/day .-. JJ. /■_. ~ 24 hours/day = 172# °*Ygen/ho rAssuming that two downdraft submerged turbines would be needed to satisfy this total- oxygen requirement, each turbine had to provide 86# oxygen/hour.The submerged turbine manufacturer recommended selection of two 40-hp turbines, each with a 15 hp blower to supply approximately 213 scfm to an air sparge assembly disposed directly below each turbine impeller.The volume of the oxidation ditch was calculated so that at high water level, with6,000 mg/1 of mixed liquor suspended solids(MLSS) in its channel, it would be possible to maintain a food-to-microorganism ratio(F/M) of 0.033 (out of a feasible range of 0.01 to 2.0), as follows: 1,475# BOD(5)/day .(8.34) (6,000# MLSS/million #mixed liquor) [.033# BOD(5)/#MLSS]'0.87 million gallons.A ditch volume of 900,000 gallons, equalling120,304 cubic feet, was selected, and the volumetric loading was calculated as follows :., .75.^(5)/^ ft. . _2_25f BOD(5)/1,000 £t3The overflow device for the oxidation ditch was then designed so that the ditch operating level could be adjusted to control volume inOMPI. A- WW11PPOO Λ in the ditch between 600,000 gallons and 900,000 gallons.The channel cross-sectional dimensions were next determined, using the turbine manufacturer's estimate that a 40-hp turbine would pump approximately 46,500 gpm, equalling 103.65 ft /sec . With two such turbines in operation, the total pumping rate would be 207.3 cubic feet per second. Using a desired circulation velocity of 1.0 ft/sec with both turbines in operation at high water level, the cross-sectional area for the channel was determined to be 200 square feet: 207.3 cfs/200 ft2 = 1.04 fps. The channel was then designed with a trapezoidal cross section as seen in Figure 3 (although rectangular, square, round, oval, or other shapes could be substituted) to furnish this flow* rate. The channel length in the oxidation ditch was then calculated: 120,304 ft3/200 ft2 = 601.5 feet.To compensate for the width of the earthen barrier 22, a distance of 20 feet was added to the ditch, giving 621.5 feet. Then the hydraulic head loss in the channel caused by wall friction was calculated by the Manning Equation for open channel flow (using n = 0.03 for a gunnite concrete liner and R = area/wetted perimeter = 200/38.19 = 5.24) :Head loss = [(Velocity x n)/(1.49 x R0'67)]2 = 0.00005 ft/ft of ditch. Head loss = (601.5) (0.00005) = 0.029 ft = 0.35 inch. The additional hydraulic head loss caused by flow turbulence around the two bends was also calculated: bend head loss = 2 (V2/2g) = 0.0336 feet. The total hydraulic head loss is the sum of these losses, equalling 0.75 inch or 0.06 feet.Each 40-hp turbine provides a flow of 46,500 gpm at a total developed hydraulic head of 2.45 feet. Adding 0.06 feet to this operating head normally has an insignificant effect on the pumping capacity of the submerged turbine, so that revising the ditch cross-sectional area in order to maintain a minimum average velocity of 1.0 fps is not necessary.This treatment is intended to reduce BOD(5) to less than 20 mg/1, TSS to less than 20 mg/1, ammonia nitrogen to less than 2 mg/1, and pH to 6-9.Example IIAn oxidation ditch, similar to but smaller than the ditch of Example T, was designed and constructed to treat wastewater effluent (sewage) from a school. This effluent had the following characteristics:Biochemical oxygen demand, BOD(5) = 200-250 mg/1 Total suspended solids, TSS = 200-250 mg/1 Ammonia nitrogen = 15 - 25 mg/1 Total Kjeldahl nitrogen (TKN) = 20 - 30 mg/1 pH = 7.0Total phosphorus = 6 - 20 mg/1 The average daily flow was 0.055 MGD, 7 days per week, according to the diurnal flow cycle of normal domestic waste. Following the procedure of Example I, calculations gave the following results, using the higher values of each range: 115# BOD(5) per day; 13.8# TKN; 223#/day of oxygen required at process conditions; 357#/day of oxygen required at standard conditions; 15#/hr of oxygen per turbine (one 10-hp submerged turbine required) ; 30 scfm of air (one 2- hp blower required); 4,000 mg/1 MLSS; 70,000 gallons, equalling 9,357 ft 3, at high water level, and 50,000 gallons at low water level;3 12.3# BOD(5) /l,000 ft as the volumetric loading;7,500 gp or 16.7 cfs as the turbine pumping rate; 1.11 fps as the flow rate in the channel;215 ft as the flow area; 624 feet as the ditch length and 10 feet as the barrier width; and 2.50 inches of head loss for the channel + 0.46 inch of head loss for the bends, equalling 3.0 inches total head loss which would reduce the turbine pumping capacity to about 7,200 gpm or 16.05 cfs, causing the flow velocity in the channel to be 1.07 fps.Example IIIAfter 71 days of continuous operation with no sludge wastage, the oxidation ditch of Example I was analyzed for dissolved oxygen. At the ends of' the ducts 29,60 in discharge channel 75, the dissolved oxygen (D.O.) was 0.6 mg/1; 50 feet downstream from the turbines 28, 30, the D.O. was 0.3 mg/1; and in theOM channel on the opposite side of the island, the D.O. was 0.1 mg/1.There was no filamentous growth, but the effluent from the clarifiers was cloudy because of suspended and colloidal material, representing unconsumed organic food. In general, the oxidation ditch seemed to be deficient in oxygen and microorganisms.Example IVThe oxidation ditch of Example I had been operated with discharge of overflow mixed liquor to the flow dividing unit 83 and thence to one of a pair of hopper clarifiers through lines 85, with no sludge wastage for 80 days. The following data was obtained from composite tests of anaerobic effluent and of clarifier overflow:INFLOW OUTFLOW250 ,000 gpd flow (7 days , 24 hrs/day) 250, 000 gpd 1, 045 BOD (5) , mg/1 83220 TKN 45NH. Nitrogen 43These results correspond to an oxygen demand of at least 7,000 pounds of oxygen per day or at least 292 pounds of oxygen per hour at standard conditions when the operat¬ ing level in ditch 10 was at 8.5 feet with two turbines in operation and about 227.5 sc≤ of air being injected under each turbine. These oxygen-transfer results are about 70% greater than those anticipated by the manufacturer of the turbines. Example VThe manufacturer of the submerged turbines used in the oxidation ditch of Example I stated that the recommended air supply rate of 216 scfm (standard cubic feet per minute) was about 80% of the maximum air supply rate that the turbine could handle without flooding, so that the flooding rate would be 270 scfm for either turbine.The turbine 28 (single-speed) and the turbine 30 (two-speed) were each connected to a separate positive displacement blower capable of delivering 233 scfm at 7.0 psig. However, the blowers could be connected for delivering their combined output to the upper sparge ring (53a in Figure 2) beneath either turbine.Because of friction caused by inadequate size of a single sparge ring, it was estimated that 430-460 scfm could be delivered to the flow path of either turbine, about 65% greater than the flood point air supply rate or about 111% greater than the operat¬ ing air supply rate recommended by the manufacturer of the turbines.The oxidation ditch of Example I has an operating depth that is variable from 7.5 feet (58 inches of turbine impeller submergence) to 10.5 feet deep (94 inches of turbine iπpeller submergence) . With the depth at 8.5 feet, about 455 scfm from both flowers were injected from the upper sparge ring of turbine 28 (single speed) , with turbine 30 (dual speed) operating at top speed butO ungassed. It was anticipated that flooding of turbine 28 would occur and that the air valves could then be closed until the turbine could handle the air being injected. However, there was no flooding of turbine 28.Example VIDual-speed turbine 30 in the oxidation ditch of Example I was shut off, and the oxidation ditch circulation velocity was allowed to slow down from about 2 fps to about 1 fps which turbine 28 could maintain alone. With all air from both blowers being injected through the upper sparge ring of turbine 28 and with ditch depth still at 8.5 feet, it operated without flood¬ ing and continued to do so for 1-1/2 hours when the test was discontinued.Example VIIBoth single-speed turbine 28 and dual- speed turbine 30 in the oxidation ditch of Example I were operated (turbine 30 being at top speed) to increase ditch velocity to about 2 fps, with depth at 8.5 feet, and all of the compressed air supply from both blowers (455 scfm) was injected under the impeller of dual-speed turbine 30. It did not flood.Example VIIISingle-speed turbine 28 was shut down. After the ditch velocity had slowed to about 1 fps, all air was again injected under impeller 35 of dual-speed turbine 30, operating at top speed with the operating depth at 8.5 feet. After about seven minutes under these conditions, turbine 30 flooded or stopped pumping.Example IXWith the oxidation ditch of Example I at an operating level of 8.0 feet, all air (455 scfm) was supplied to turbine 28 with turbine 30 at top speed but ungassed.Turbine 28 flooded. The other successful tests at 8.5 feet (i.e., the tests of Examples VI and VII) were attempted, but flooding occurred in each instance.Example XThe level in the oxidation ditch of Example I was raised to about 9.75 feet (64 inches of submergence) . All successful tests at 8.5 feet were easily reproduced. Moreover, when all air (455 scfm) was supplied to dual-speed turbine 30 (operative at top speed) , with turbine 28 shut down and the ditch velocity at about 1 fps (thus reproducing Example VIII except for the depth) , turbine 30 did not flood.Example XIEach turbine 28, 30 is operated to pro¬ duce a flow velocity in the channel of the oxidation ditch 10 of Example I of about 2 fps. About 460 scfm of compressed air is sparged below the turbine blades 35 SUR OM through both sparge rings 53a, 53b of each turbine. Neither floods, and the clarifier outflow is clear, indicating that all organic food is consumed. Because it will be readily apparent to those skilled in the art that innumerable variations, modifications, applications, and extensions of these embodiments and principles can be made without departing from the spirit and scope of the invention, what is herein defined as such scope and is desired to be protected should be measured, and the invention should be limited, only by the following claims.•BUREAtTOMPI | Clai s1. In a closed-circuit oxidation ditch comprising a wastewater inlet, an outlet to a clarifier, a return sludge inlet, and an endless channel having a bottom, opposed sides, and a substantially uniform cross- sectional area in which a circulating mixed liquor, containing a bacterial floe including heterotrophic aerobic, hetero- trophic facultative and autotrophic microorganisms, circulates translationally at a circulation velocity sufficient to maintain said floe in suspension, said floe utilizing wastewater entering said channel through said wastewater inlet as a food source at a food-to-microorganism ratio by weight of 0.01 to 2.5 pounds of five-day biochemical oxygen demand per pound of mixed liquor suspended solids, the impro.vement comprising a flow-control apparatus which provides repetitive aerobic treatment at least once per circuit-flow cycle to all of said mixed liquor within said endless channel and comprises: A. a barrier which is sealably attached to said bottom and said sides and is disposed athwart said endless channel to divide said mixed liquor and said endless channel into upstream liquor within an intake channel and downstream liquor within a discharge channel;' UROM B. an axial-flow pump, comprising a down-flow impeller, an intake funnel which is disposed above said impeller and in flow connection with said upstream liquor, an air sparge means for producing air bubbles which is disposed beneath said impeller, and a downdraft tube surrounding said impeller and said air sparge means;C. a mounting means for mounting said axial-flow pump in said flow connection with said upstream liquor;D. an aeration means for creating a liquid-air mixture, comprising said air sparge means, a source of compressed air, and a delivery means for moving said compressed air from said source to said air sparge means; andE. a discharge duct which connects said downdraft tube to said discharge channel, whereby operation of said axial- flow pump and said aeration means:1) forces all of said mixed liquor to flow through said discharge duct,2) creates a liquid-air mixture within said discharge duct,3) transfers oxygen from said liquid-air mixture to said all of said mixed liquor to form an aerated mixed liquor as said downstream liquor,4) completely prevents back-mixing of said aerated mixed liquor to said intake channel, 5) is capable of controlling said upstream liquor at an anoxic level of about 0.1 mg/1 or less of dissolved oxygen, and 6) increases the log mean driving force for oxygen transfer across said intake funnel and the discharge end of said discharge duct, thereby decreasing the energy required for dissolving a given quantity of oxygen in said mixed liquor and increasing the oxygen transfer efficiency, while providing said repetitive aerobic treatment to said all of said mixed liquor within said endless channel and translationally circulating said mixed liquor at said sufficient circulation velocity to maintain said bacterial floe in said suspension.2. The improved oxidation ditch of claim 1 wherein said barrier means is an earthen barrier having a trapezoidal cross section and covered with a layer of gunnite.3. The improved oxidation ditch of claim 1 where¬ in said flow-control apparatus comprises at least two said axial-flow pumps, at least two said mounting means, at least two said aeration means, and at least two said discharge ducts in side-by-side relationship.OM The improved oxidation ditch of claim 3 wherein said discharge ducts converge toward said discharge channel.The improved oxidation ditch of claim 1 wherein said discharge duct passes beneath said barrier at a greater depth than said bottom of said endless channel, whereby a pressure is generated upon said liquid- air mixture that is greater than the hydraulic pressure at said bottom. The improved oxidation ditch of claim 5 where¬ in said discharge duct is flow-connected to said downdraft tube, leads downwardly to a selected depth, curves in a downstream direction for a selected distance, and leads upwardly to a discharge point within said discharge channel.The improved oxidation ditch of claim 6 wherein said discharge duct is extended in the direction of flow of said mixed liquor within said discharge channel for a sufficient distance that substantially all of said repetitive aerobic treatment occurs within said discharge duct and under a selected hydraulic pressure that is greater than the pressure corresponding to the depth of said channel.The improved oxidation ditch of claim 6 wherein said discharge duct comprises a • curved discharge section which is connected to said downdraft tube, a first straight section which is connected to said curved discharge section, an updraft section which is connected to said first straight section, a second straight - section which is connected to said updraft section, and a terminal duct which is connected to said second straight section and is disposed in said discharge channel.9. The improved oxidation ditch of claim 8 wherein said air sparge means comprises at least one air sparge ring.10. The improved oxidation ditch of claim 9 wherein said air sparge means comprises a primary sparge ring and a secondary sparge ring which are disposed athwart• the flow of said mixed liquor through said downdraft tube.11. The improved oxidation ditch of claim 8 wherein said aeration means comprises a sparge tube which is disposed within said discharge duct to provide supplementary air when BOD loads are very heavy and when it is desirable to substitute discharge duct aeration for pump aeration because of flow rate considerations, so that the velocity of upwardly translational movement through said discharge duct is increased by an air-lift pumping effect acting in addition to the pumping effect of said down-flow impeller.12. The improved oxidation ditch of claim 11 wherein said sparge tube is transversely disposed within said discharge duct.13. The improved oxidation ditch of claim 11 wherein said sparge tube is removably mounted within a casing pipe which is sealably attached to said discharge duct.OM ■41-14. The improved oxidation ditch of claim12 wherein said casing pipe is attached to said first straight section.15. The improved oxidation ditch of claim 13 wherein said casing pipe is attached to said updraft section.16. The improved oxidation ditch of claim13 wherein a plurality of said sparge tubes are removably mounted within a plurality of said casing pipes, one said casing pipe being attached to said first straight section and another, said casing pipe being attached to said updraft section.17. In an activated sludge process for aerobically treating a continuous stream of wastewater by continuously admixing said stream with a quantity of circulating mixed liquor which:(a) contains a biomass including heterotrophic aerobic, heterotrophic facultative, and autotrophic micro¬ organisms which exist at least partially as a bacterial floe and for which said wastewater is a food source at a food-to-microorganism ratio by weight varying over a range of 0.01 to 2.5 parts of five-day biochemical oxygen demand per part of mixed liquid suspended solids,(b) flows translationally within the endless channel of an oxidation ditch at a circulation velocity that is sufficient to maintain said floe in in a state of suspension therewithin without interruption by a clarification, zone within said channel so that said admixing occurs once per circuit- flow cycle of said oxidation ditch,(c) is diminished by a portion thereof being continuously discharged to a settling means for separating clarified liquor from settled sludge, and(d) is increased by at least a part of said settled sludge being continuously returned to said channel, the improvement comprising the following stepsA. providing a barrier means, disposed within said channel, for dividing said mixed liquor and said channel into upstream liquor within an intake channel and downstream liquor within a discharge channel;B. providing a discharge duct which connects said upstream liquor to said downstream liquor;C. providing a pump means for pumping all of said upstream liquor through said discharge duct from said intake channel to said discharge channel;D. providing an aeration means for introducing compressed air to said all of said intake liquor passing through said discharge duct; andE. operating said pump means and said aeration means in order to: 1) cyclically force all of said mixed liquor through said discharge duct,2) form a liquid-air mixture within said discharge duct,3) transfer oxygen from said liquid- air mixture to said all of said mixed liquor to form an aerated mixed liquor as said downstream liquor,4 ) completely prevent backmixing of said aerated mixed liquor to said intake channel , and5 ) increase the log mean driving force across the intake and discharge ends of said discharge duct, thereby decreasing the energy required for dissolving a given quantity of oxygen in said mixed liquor and increasing the oxygen transfer efficiency while providing said repetitive aerobic treatment to said all of said mixed liquor within said endless channel and trans lationally circulat- ing saia mixed liquor at said sufficient circulation velocity to maintain said bacterial floe in said state of suspension. The improved activated sludge process of claim 17 wherein said food-to-microorganism ratio varies over the range of 0 . 01 to0. 2 and said mixed liquor has at least 3 , 000 mg/1 of mixed liquor suspended solids , whereby said oxidation ditc operates as an extended aeration system.19. The improved activated sludge process of claim 17 wherein said returned part of said settled sludge enters said intake end of said discharge duct.20. The improved activated sludge process of claim 17 wherein at least a portion of said discharge duct is at a greater depth than the depth of said discharge channel.21. The improved activated sludge process of claim 20 wherein said discharge duct is extended at said greater depth for a sufficient distance that substantially all of said repetitive aerobic treatment occurs within said discharge duct and under a selected hydraulic pressure that is greater than the pressure corresponding to said depth of said discharge channel.22. The improved activated sludge process of claim 17 wherein said pump means is a shear-type pump means for shearing substantially all of said bacterial floe into smaller particles.23. The improved activated sludge process of claim 22 wherein a shear means is additionally provided within said dis¬ charge duct.24. The improved activated sludge process of claim 19 wherein said pump means is an axial-flow pump, comprising a down- flow impeller, an intake funnel which-β -O is disposed above said impeller and' in flow connection with said upstream liquor, an air sparge means for producing air bubbles and forming said liquid-air mixture, and a downdraft tube surrounding said impeller and said air sparge means, said intake funnel and said downdraft tube being connected as said intake end of said discharge duct. 25. The improved activated sludge process of claim 24 wherein said air sparge means comprises at least one sparge ring which is disposed below said down- flow impeller within said downdraft tube. 26. The improved activated sludge process of claim 25 wherein a plurality of said pump means, said aeration means, and said discharge ducts are provided and wherein said aeration means further comprises at least one sparge tube which is removably disposed within each said discharge duct.27. The improved activated sludge process of claim 26 wherein by varying the proportion of said compressed air fed to each said sparge ring and each said sparge tube, said velocity is varied by at least 50 percent.28. The improved activated sludge process of claim 27 wherein said oxidation ditch is selectively operable:A. to provide aerobic and anoxic zones within said channel-BU EAT-OMPI -A. for combined nitrification and denitrifica- tion of said wastewater; andB. to vary the lengths of said aerobic and anoxic zones in accordance with seasonal temperature changes.29. The improved activated sludge. process of claim 28 wherein said oxidation ditch is selectively operable by varying:(a) the operation of said impellers singly or in parallel,(b) the speeds of said impellers,(c) the total amount of said compressed air, and(d) the proportion of said compressed air between said sparge rings and said sparge tubes, whereby:(1) said velocity is variable over a range of from 0.5 ft./sec. to at least 3.0 ft./sec. while maintaining a selected dissolved-oxygen out¬ put from said discharge ducts , or(2) said dissolved-oxygen output is variable while maintain¬ ing a selected velocity, or(3) both said velocity and said dissolved-oxygen output are variable in any desired combina- tion while operating all said turbines at a constant speed.-BU -47-30. The improved activated sludge process of claim 29 wherein said continuous stream of wastewater is delivered to said channel within said anoxic zone and upstream of said intake channel in order to enable certain of said microorganisms, that are present in said anoxic zone and use nitrate oxygen as their oxygen source and hydrogen sulfide as their energy source, to maximize denitirifica- tion. and to minimize consumption of free dissolved oxygen for chemical and biological oxidation of said hydrogen sulfide, thereby enabling said free dissolved oxygen to be used to a maximum extent for biological BOD removal and nitrification, by utilizing nitrate oxygen that is available in said circulating mixed liquor for oxidation of said hydrogen sulfide that is present in said continuous stream of wastewater.31. The improved activated sludge process of claim 30 wherein said anoxic zone is at an anoxic level of about 0.1 mg/1. or less of dissolved oxygen. | REID J | REID J |
WO-1979000263-A1 | 1,979,000,263 | WO | A1 | EN | 19,790,517 | 1,979 | 20,090,507 | new | F03C3 | null | F03C2, F04C15 | F03C 2/30C, F04C 15/06 | HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT | A constant displacement reversible hydraulic vane motor capable of being used in power hydraulic systems, hydrostatic transmissions, and the like. In existing motors with vanes mounted in the rotor and inlet and exhaust passages in the housing great sophistication in the grinding, assembly, and maintenance of the system is required. The simplified motor of this invention has a rotor (2) with a symmetric lobular outline which is engaged by vanes (22) to (29) mounted in a circular housing (1). The fluid to drive the motor enters through groove (10), orifices (12) and passages (20) and exhausts through passages (19), orifices (13) and groove (11) all in the rotor. Fluid supplied through the rotor enables the motor to operate at uniform speed without torque oscillation. | HYDRAULIC MOTOR WITH VANE S AND CONSTANT DI SPLACEMENT . a) TE CHNICAL F IELD :This application for the privilege of invention refers to a hydraulic revertible motor, with vanes, an only rotor and constant displacement, applicable to powerful hydraulic sys¬ tems, hydrostatic transmission, etc. b) BACKGROUND ART:The hydraulic motors which are technically more similar to the invention are the hydraulic motors with vanes made by Norwinch and by Brattvaag both of Norwegian origin. Norwinch low pressure hydraulic transmission normally works in closed circuit. The motor itself consists of a cylindrical rotor where eight sliding vanes (radial) are placed and alternately linked two by two by means of an also sliding arched spindle (the vanes are not rigidly linked to that spindle but only in contact with it); the case has an approximately elliptical shape and both the oil inlet and outlet in it. The vanes are always kept in'contact with the case, because when one vane is contracted (position in which the rotor and the case are in contact) , it pushes the linking spindle which, at the same time, expels the opposite vane, always following the housing curve. The Brattvaag hydraulic motor consists of a cylindrical, square or even dodecagonal rotor where the vanes are placed radially. The number of vanes varies from 4 to 12, depending on the motor. For this motor the housing has various shapes depending on the respective rotor. The vanes are always kept in contact with the housing walls by means of the pressure of the oil that is sent through the rotor grooves up to the interior of the vane chambers, causing, thus, the tendency to expel them. In both motors great sophistication is required in the plants, assembly and maintenance of the systems. c) DISCLOSURE OF INVENTION: The present motor has its sliding vanes in compartments in--BU REΛOMPI ™° side the motor casing and a fluid injection system through grooves in the rotor itself. This characteris ic allows a hy drostatic suspension of the rotor inside the housing, no mat ter what the load conditions are. It works in a either closed or open oil circuit with an oil reservoir, an oil hea exchanger, a control valve system and a hydraulic pump, gear ings or axial or radial pistons with enough power for the desired use . The motor speed variation can be achieved by using either a variable outflow pump or adequate outflow regulating valves. On figure 1, we can see on the housing (1) the bolt-holes (14) for the screws (21), one of the vane operation circuit grooves (15), the vanes (22) to (29) in their chambers, the rotor (2) , the side oil grooves (10) and (11), communicant . orifices (12) and (13) of the internal and external grooves (11), (10), the axle (4) and the internal passages (19) , (20 linking the communicant orifices (12), (13) to the rabbets (18) on the non-cylindrical faces of the rotor (2). On figure 2, we can see the rotor (2) and its side grooves (10) , (11) which enable the hydraulic pressure balance on th sides of the rotor, the oil inlet (16) into the external grooves (10) the passing screws (21) for fixing the lids (5) and (6), to the casing (1) of the motor, one vane (24), the oil circuit side grooves (15) for actioning the vanes, the oil supply tube (17) for that circuit, the bearings (8), the chambers for the retainers (9) , the bearing covers (7) and the axle (4) .Description of the behaviour principle of the hydraulic moto at issue: Based on figure 1, suppose that the external grooves (10) of the rotor (2) are connected to the hydraulic pump of the sys tem. Obviously, the internal grooves (11) of the rotor (2) will be in communication with the motor outlet. No matter the angular position of the rotor (2), the vanes (22) to (29) will be leaning on the sliding surface of the rotor (2). The communicant orifices (12) of the external grooves (10) are connected to the rotor (2) rabbets by means of internal passages (.20) . The oil coming from the pump passes through the e-xternal grooves (10), communicant ori¬ fices (12) and internal passages (20) . In this way the flow ,, is retained by the vanes (22) and (26) and the resultant ρres_ sure acting on the faces of the rotor (2) will cause its clockwise revolving movement, until the vanes (23) and (27) lean on the internal circumferential trail of the rotor (2) . At that moment these ones will prevent the oil flow, assuring the continuity of the rotor movement. Because of the movement of the rotor (2) , the dammed up oil which is between the vanes (22) to (29) forces its way-out b ' the nternal pas¬ sages (19) through the internal grooves' (11) communicant ori. fices (13), towards the motor outlet. To achieve the gear reversion of the motor it is enough to invert the outlet and inlet by means of a directional valve inserted in the hydraulic circuit of the system. The contact between the vanes and the sliding trail of the rotor is provided by the vane operation oil circuit along the side grooves (15). This circuit is pressurized by the mo- tor itself. The completely hydraulic circuit allows the vanes and rotor wastage without affecting the total capacity of the motor, thus increasing the endurance' of the equipment. The fluid injection,.system through the s-ide grooves of the rotor keeps the same diameter grooves -under the same pressure on both sides of the rotor so that., no matter the load condi¬ tions, the rotor will be hydraulicall.y balanced axlewise, re¬ ducing the wastage By mechanical friction and increasing the efficiency of the motor. We have thus, a hydraulic motor of extremely smooth operation., completely uniform speed and without any torque fluctuation whatsoever.As in the present motor the areas under the same hydraulic pressure are always opposite as far as the longitudinal axle is concerned, there is no radial tension on the traction axle. d.) BRIEF DESCRIPTION OF DRAWINGSThe descriptive figures below show constructive details of this invention and are component parts of this privilege ap-OMPI. wipo v , plication.Figure - n. 1 shows the motor axlewise without the side lid and with the vanes and the rotor.Figure n. 2 shows a longitudinal cut of the motor.• 5 e) BEST MODE OF CARRYING OUT THE INVENTIONThe invention must be performed so that there be a minimum vane and rotor wastage without affecting the total efficien¬ cy of the motor. Therefore the contact surface of the rotor vanes must have the same radio so as to make the finishing10 easy by means of face grinding as well as its ulterior assem bly. On the other hand, the geometric configuration of the rotor, the rabbets on its non-cylindrical surfaces, and the vane arrangement in the case must enable the alternation of the vanes in restraining the oil flow to be carried out in a15 uniform and smooth way. f) INDUSTRIAL APPLICABILITYThe present invention provides a new hydraulic vane motor, extremely simple and with exceptional operational character¬ istics in any duty conditions, especially adequate for equip20 ment that demand wide speed range without the least torque oscilation.It is advisable in equipment that needs smooth actioning at high speed and accuracy in reply, high degree of reliability and system denseness. Apart from that, it permits great plan25 flexibility, as for example in sugar cane grinding equipment cranes, etc.Thus, this invention solves the problems for all the uses where high torque and low rotation are need which have up to the moment been solved through extremely sophisticated30. imported equipment as previously described or by complex me¬ chanical systems which are far from being reliable and safe.OMPI4 A WIPO | CLAIMS1 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, characterized by the fact of having an only symetrical lobular outline rotor (2), assembled in a circular case (1) with chambers for the vanes (22) to (29) and oil supply sys¬ tems through the rotor (2) allowing the operating under a perfectly uniform speed regime without torque oscilation.2 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, according to claim 1, characterized by the fact that the ro- tor (2) has oil side grooves (10) and (11) , on both sides to enable the hydrostatic suspension of the rotor (2) at the most different duty conditions, assuring correct self-loca¬ tion of the rotor (2) between the two covers (5) and (6) with the least mechanical wastage. 3 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, according to claims 1 and 2, characterized by having rabbets (18) on the non-cylindrical surfaces of the rotor, which ena¬ ble the alternation of the vanes in retaining the oil flow without damaging the continuity of the traction torque. 4 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, according to claims 1, 2 and 3, characterized by having a hy¬ draulic circuit for vane operation (22) to (29) as the only operation means, pressurized by the very inlet line of the motor, constituted by two grooves (15), one on each side of the casing (1) imediately above the vanes (22) to (29) and linking all the vane chambers. | OLIVEIRA H | OLIVEIRA H |
WO-1979000264-A1 | 1,979,000,264 | WO | A1 | EN | 19,790,517 | 1,979 | 20,090,507 | new | F03C3 | null | F03C2 | F03C 2/30C | HYDRAULIC PRESSURE MOTOR WITH LOW SPEED AND HIGH TORQUE | A hydraulic pressure motor with low speed and high torque for applications in mechanical engineering mainly in large-sized equipment, hydrostatic transmissions, and the like. Current hydraulic motors have countless moving components and a high degree of sophistication so that the complexity of the system requires careful maintenance and high cost. The constant displacement motor of this invention is extremely simple, long-lasting, and capable of use under the most severe conditions. It has two similar rotors (4) which operate in separate axially spaced chambers. The rotors are displaced from each other by 90` and are engaged by sluice-valves (7) which separate the pressure chambers of the motor. Cuts (13) on the rotor (4) or casing (1) provide pressure relief and allow sluice-valve (7) withdrawal without lateral pressure thereon. The displaced rotors (4) assure smooth operation. | HYDRAULIC PRESSURE MOTOR WITH LOW SPEED AND HIGH TORQUE. a) TECHNICAL FIELDThe present invention refers to a hydraulic motor with high torque and low speed particularly adequate for large-sized units in applications that demands potential power and where endurance, reliability and simplicity in the maintenance of the equipment are of real importance. Potential power hydraulic systems are widely used in a large number of applications due, mainly, to the versatility, reli¬ ability and operational characteristics, b) BACKGROUND ARTThe hydraulic motors that develop high torque are generally provided with radial pistons (Staffa, Sundstrand and others) and they operate at much higher pressure. Those motors have countless moving components and a great sophis ication to reduce the efficiency loss because of the mechanical fric¬ tion of its components. The complexity of the system brings about a much more care- ful and expensive maintenance. The ver .manufacturing of those motors is rather complex and at high cost so as to garantee acceptable levels, of performance.Apart from that, there are vane hydraulic motors, such as the ones made by the Norwegian firms Norwinch and Brattvaag which are the more similar ones to the one herein presented. The Norwinch low pressure hydraulic transmission generally works in a closed circuit. The motor itself consists of a cylindrical rotor where eight sliding vanes are placed and linked two by two alternately by means of an also sliding arched spindle (the vanes are not attached to that spindle but just in contact with it).The case has an approximately elliptical shape including both the oil inlet and outlet. The vanes are always kept in contact with the case and when a vane is contracted (posi- tion in which the rotor and the case are in contact) , it pushes the linking spindle which expels the opposite vane, always following the case curve. The Brattvaag hydraulic motor consists of a cylindrical, square or even dodecagbnal rotor in which the vanes are ra¬ dially placed. The number of vanes varies from 4 to 12 de¬ pending on the motor. In this motor the case has a differ- •5 rent shape depending on the respective rotor. The vanes are always kept in contact with the case walls by means of the pressure of the oil which is sent into the vane chambers through the grooves in the rotor and which tends to expel them. 0 In both cases, the project is highly sophisticated as -w-e .a-s- the piston motors demand a fairly complex manufacturing process and a careful and expensive maintenance. c) DISCLOSURE OF INVENTION Like all hydraulic motors, no matter its kind, the present 5 invention is the traction operating part of a potential power hydraulic motor, which must have a hydraulic pump which will generally be the positive displacement type,with vanes, gearings, axial pistons, etc. This pump is responsi¬ ble for the fluid supply of the hydraulic motor through a 0 hydraulic circuit that may have an oil reservoir, filters, safety and relief valves, outflow regulating valves, direc¬ tional valves, etc.The hydraulic pump of the system can be operated through any known means (eletric engines, internal combustion en- 5 gines, turbines, etc) as far as it is adequate to its poteri tial power and operation characteristics.The motor in question has constant displacement and a se¬ ries of constructive characteristics which make it quite - strong, extremely simple and capable of bearing the most 0 severe load conditions in all kinds of equipment. Its con¬ ception allows a fairly smooth and uniform operation at a rotation rate of Ir.p.m. under full load conditions. The operating principle of this motor is fairly simple. The two chambers in the motor are fed by two independent fluid 5 circuits. Each chamber has two opposite oil inlets and out¬ lets, linked to one another by each of the head-shafts. The rotors in the chambers are displaced at 90 . The sluice-valves are totally devised according to the de¬ sign on figure 3. The fluid coming from the pump fills the volume of the rotor (4) lobule; the case (1), the main cov¬ er (2) and the sluice-valves (7) . The load on the shaft brings about the hydraulic pressure in the chamber. This pressure is limited by the characteristics of the pump and the structural dimension of the motor. As the fluid pres¬ sure acts on the rotor (4) it provides a force component* perpendicular to the shaft bringing about the traction torque . Because of the rotation movement of the shaft and the rotor (4) the sluice-valve (7) will be withdrawn at the start of the rotor (4) ascendant curve. At this stage a rabbet on the ro¬ tor (4) or on the case (1) causes a pressure relief in the chamber and the sluice-valve (7) whose main function is that of a reaction plate, acquires free movement in its seat, without lateral pressure effect. The start of the sluice-valve (7) withdrawn in one rotor (4) shows the. start of the other rotor operation, displaced at 90 , whose valves are actioned by the oil pressure on the inlet. In this way, the rotors (4) work alternately assuring the continuity of the movement. The oil ejection takes place si¬ multaneously to its admission, through the rotor (4) lobule, by means of the outlet orifice in the rear part of the valve (7). d) BRIEF DESCRIPTION OF DRAWINGSThe motor is basically formed by a case with two different chambers, each of them with its rotor and separate by an in¬ ternal wall, as shown on the attached figures: Figure 1 - shows an axlewise view of the motor case; Figure 2 - shows a lateral view of the casing lead-shaft; Figure 3 - shows the rotor in its chamber; Figure 4 - shows a cut of the upper part of the set; Figure 5 - shows an expanded view of the motor with its main components in one of the chambers. In figures 4 and 5, we can see the case (1), the main covers (2), the bearing -covers (3), two rotors (4), the head-shaft covers (5), the axle (6), the sluice-valves (7), the bearings (8), the sealing-rings (9) and (10), the stud-bolts (11) for fixing the covers to the case (1) and the bearing cover scre (12), the rabbets (13), the chambers (14) the lateral guides (15) of the sluice-valves (7). e) BEST MODE OF CARRYING OUT THE INVENTIONThe following constructive details which identify the concept of the present invention, should be pointed out: The sluice-valves (7) which separate the pressure chambers from the oil chambers run on lateral guides in the case and cover of the motor and have just & seesaw movement. Such a la eral guide arrangement assures a better rigidity of the valve apart from allowing the manufacturing of larger and more dura ble components so that higher torque and more safety for the motor components are achieved. Another peculiar characteristic of this motor are the rabbet on the rotor (4) and/or the case (1) . Such rabbets provide th pressure relief, in one of the chambers together with the re¬ sultant torque decrease which is immediately assured by the other chamber rotor, displaced at 90 . Thus, the sluice-valves (7) when in movement are not laterall actioned by the operation pressure of the motor. This characteristic allows really lower wastage levels of the sluice-valves (7) and of the sliding area of the rotors (4) increasing the endurance of the set. Another characteristic of this motor is that the rotor (4) outline curve is such that the load of one rotor (4) can be transferred to the other with extreme smoothness and really low speed fluctuation. It is clear that the'motor shaft is no radially actioned. Therefore, it is not submitted to flexure because the chamber under the same pressure are opposite shaftwise. Apart fro that, the geometry of the rotors enables an easy me¬ chanical balance. It is also understood that the traction torque obtained on the shaft, is a consequence of the geom- etry and size of the motor as well as the pressure differen¬ tial between the pressure and the oil oulet chambers. The efficiency of the set depends mainly on the fairly reduced mechanical friction as a result of the very low number of ov ing components and on the perfect internal sealing between the zones of high and low pressure which can be obtained through accuracy.in the components grinding. f) INDUSTRIAL APPLICABILITYThe present invention due to its simple conception with low number of components, easy to manufacture and constructive solutions that search for more enduring components, and espe¬ cially adequate for large-sized units for application of high torque and at low speed allowing the research of new fields in the application of high powered hydraulic systems also attending to the utility needs of highly reliable equip¬ ment, low cost manufacturing, simple maintenance, and also capable of replacing conventional actioning systems with effi_ ciency acquisition and therefore less power-consumption. | CLAIMS 1 - A HYDRAULIC PRESSURE MOTOR WITH LOW SPEED AND HIGH TORQU which differs from the existent vane motors (Norwinch and Brattvaag) principally due to the fact that these have vari- ous vanes radially placed on the rotor and always kept in co tact with the case through mechanical means (Norwinch) or hy draulic pressure in a highly sophis icated way, thus, causing difficulties as far as the plant and assembly are concerned, while the hydraulic motor in question is characterized by having two rotors (4) with double outline assembled on the same shaft (6) separate by an .internal wall, with four hori¬ zontal sluice-valves (7) , placed laterally on the case (1) making the manufacturing process and assembly simple and at low cost. 2 - A HYDRAULIC PRESSURE MOTOR WITH LOW SPEED AND HIGH TORQU according to claim one characterized by having internal cuts or rabbets (13) on the case (1) or on the rotor (4) to pro¬ vide a bleeding in the oil flow every 1/4 of a rotation, wit the consequent fall in the internal pressure permitting in this way the withdrawal of the sluice-valves (7) to their respective chambers (14) to be carried out without the par¬ ticipation of the lateral pressure.3 - A HYDRAULIC PRESSURE MOTOR WITH LOW SPEED AND HIGH TORQU according to claims one and two, characterized by having the chambers (14) of the sluice-valves (7) built in the case (1)4 - A HYDRAULIC PRESSURE MOTOR WITH LOW SPEED AND HIGH TORQU according to claims one, two and three, characterized by hav ing semi-cylindrical sluice-valve (7) chambers on the later al guides (15) of the case (1) and principal covers (2) and according to the shape of the sluice-valves (7) .5 - A HYDRAULIC PRESSURE MOTOR WITH LOW SPEED AND HIGH TORQU according to claims one, two, three and four, characterized by having the same hydraulic pressure in the opposite volume in relation to the shaft (6) during the operation of the mo- tor. These volumes are held by the rotor lobule (4) of the case (1) principal cover (2) and sluice-valves (7) .OMP | OLIVEIRA H | OLIVEIRA H |
WO-1979000266-A1 | 1,979,000,266 | WO | A1 | XX | 19,790,517 | 1,979 | 20,090,507 | new | C08L23 | C08L23 | C08L23, C09J123 | C09J 123/16+B2, C09J 123/18+B2 | HOT MELT,PRESSURE SENSITIVE ADHESIVES | Blends of compatible tackifying resin with substantially amorphous olefin copolymers containing a C<u3>u to C<u5>u linear //c-olefin and 40 to 60 mole percent of a C<u6>u to C<u10>u linear //c-olefin which are useful as hot-melt, pressure-sensitive adhesives. The unmodified copolymer bases resins have melt viscosities in the range of > 75,000 cp up to 1,000,000 cp at 190`C. The addition of the compatible tackifying resins to the copolymer base resin causes an addition to improved coatability as well as substantial increases in probe tack and peel adhesion values of the copolymers. | HOT-MELT, PRESSURE-SENSITIVE ADHESIVES Background of the InventionThis invention relates to hot-melt pressure- sensitive adhesive compositions having a novel combination of properties. More specifically, the invention relates to blends of compatible tackifying resins with substantially amorphous olefin copolymers containing a C to C,- linear α-olefin and 40 to 60 mole percent of a Cg to C,Q linear -olefin which are useful as hot-melt, pressure-sensitive adhesives.Description of the Prior ArtIn U.S. Patent 3,954,697 propylene/higher 1- olefin copolymers containing 40 to 60 mole percent higher 1-olefin and having melt viscosities up to 75,000 cp (measured by ASTM D1238) were coated by hot-melt techniques on backing materials and they were disclosed as having good pressure-sensitive adhesive properties. However, copolymers with melt viscosities greater than 75*000 cp are difficult to coat and the coatings have striations in them. The copolymers with melt viscos¬ ities greater than 75*000 cp have not been useful as pressure-sensitive hot-melt adhesives prior to our in¬ vention. Summary of- the Invention In accordance with our invention, we have found that blends of copolymers having melt viscosities greater than 75,000 cp and containing amorphous olefin copolymers containing a C~ to Cj- linear α-olefin and 40 to 60 mole percent of a Cg to C-,Q linear α-olefin with compatible tackifying resins are useful as pressure-sensitive hot-melt adhesives. The addition of the tackifying resin to the copolymer having a melt viscosity greater than 75,000 cp results in a substantial reduction of the melt viscosity and an unexpected improvement in the adhesive properties so that the blends can be used as pressure-sensitive hot-melt adhesives. For example, the addition of compatible tacki¬ fying resins to substantially amorphous olefin copolymers derived from a monomer selected from propylene, 1-butene or 1-pentene with 40 to 60 mole percent of a higher α-olefin of 6 to 10 carbon atoms and having a melt viscosity greater than 75,000 cp causes an unexpected increase in the shear adhesion failure time in addition to substantial increases in probe tack and peel adhesion values of the copolymers. Detailed Description of the InventionThe hot-melt pressure-sensitive adhesive com¬ positions of our invention contain from 50 to 95 weight percent of the olefin copolymer and from 5 to 50 weight percent of a compatible tackifying resin. Preferred com¬ positions contain 60 to 90 weight percent of the olefin copolymer and 10 to 40 weight percent of a compatible tacki¬ fying resin.The compatible tackifying resins useful in the adhesive compositions of this invention can be a hydrocarbon resin such as DAC-B hydrocarbon resin prepared according to the process disclosed in U.S. Patent 3,701,760 as well as other hydrocarbon resins, polyterpenes or synthetic poly- terpenes, and the like. One such DAC-B hydrocarbon tacki- fying resin is a hydrocarbon resin having a softening point of 100°C. and available commercially as Resin H-100 from Eastman Chemical Products, Inc. Other hydrocarbon tackifying resins can be prepared by the polymerization of monomers consisting primarily of olefins and diolefins and. include, for example, the residual by-product monomers resulting from the manufacture of isoprene. These hydro¬ carbon tackifying resins typically exhibit a Ring and Ball softening point of from 8θ°C. to 135°C; an acid number of 0-2, a saponification value of less than 1; and an iodine value of 30 to 100. Examples of such commercially available resins based on a C^-olefin fraction of this type are Wingtack 95 and Wingtack 115 tackifying resins sold by Goodyear Tire and Rubber Company, the Sta-Tac and Betaprene A or H resins sold by Reichhold Chemical Corporation, Arkon resins sold by Arakawa Forest Chemical Industries, and Escorez resins sold by Exxon Chemical Co.Also other suitable tackifying resins are the terpene polymers such as the polymeric, resinous mat- erials obtained by polymerization and/or copolymeriza- tion of terpene hydrocarbons such as the alicycllc, monocyclic, and bicyclic monoterpenes and their mix¬ tures, including alloocimene, carene, isomerized pin- ine, pinene, dipentene, terpinene, terpinolene, limonene, terpentine, and various other terpenes. Particularly use¬ ful starting materials are terpene mixtures containing at least 20 percent by weight beta-pinene and/or lim¬ onene or dipentene (race ic limonene), and the sul ate terpentine obtained as a by-product in the sulfate pulping process. Commercially available resins of the terpene type include the Zonarez terpene B-Series and 7000 Series resins from Arizona Chemical Corp. and Nirez resins from Reichhold Chemical Corp. The typical properties reported for the Zonarez terpene resins in- elude Ring and Ball softening points of 55 to 125°C. (ASTM E-28-67), color of 2 to 3 (Gardner 1963, 50* in heptane), acid number of less than 1 (ASTM D465-59), saponificatlon number of less than 1 (ASTM D464-59) and specific gravity at 25°C. of 0.9β to 0.99 (ASTM DI963- 61).The hydrocarbon resins, polyterpenes, or other compatible tackifying resins can be used either alone or in combination. The operable concentration of these tackifying resins is 5 to 50 weight percent. The preferred concentration range for these compatible tackif¬ ying resins is 10 to 40 weight percent. Incom¬ patible tackifying resins such as those based on wood rosin esters or polyindene are not useful in the prac¬ tice of this invention since blends containing them are grainy and hazy. Furthermore, the presence of the incom¬ patible tackifying resins reduces the tack of the co¬ polymers to a very low level. The base copolymers for the blends of this invention may be made according to the procedure des¬ cribed in U.S. Patent 3,954,697. Operable melt vis¬ cosity limits for these copolymers include >75,000 cp up to 1,000,000 cp, with the preferred melt viscosity range being >75,000 cp to 850,000 cp at 190°C. Such copolymers contain 40-60 mole percent higher-1-olefin and for all practical purposes are essentially amor¬ phous. For example, these useful copolymers show little or no crystallinity by either X-ray or DSC tech- niques.It was also found that Tg and density measure¬ ments are useful for the characterization of useful copolymers. One suitable method for measuring the Tg (glass transition temperature) of polymers is by Dlf- ferential Scanning Calorimetry [John Mitchell and Jen Chlu, Anal. Chem. Annual Reviews, 4_3 267R (1971); . J. O'Neill and R. L. Fyans, Design of Differential Scanning Calorimeters and the Performance of a New System , paper presented at the Eastern Analytical Symposium, New York City, November, 1971]. Density of polymers is determined in a density gradient tube (ASTM Method D1505). The copolymers used in our adhesive have a density of< 0.86 and a Tg between the Tg of poly¬ propylene (or poly-1-butene) and the Tg of the higher poly-1-olefins. For example, polypropylene has a Tg of about -20°C. and poly-1-hexene has a Tg of about -50°C. (J. Brandrup and E. H. Immergut, Editors, Polymer Hand¬ book , Intersclence Publishers, New York City, 1966). Useful propylene/1-hexene copolymers containing 40-60 mole percent 1-hexene normally show Tg values of -30 to -45°C. If the copolymer is too blocky (i.e., con¬ tains relatively long segments of propylene), the co¬ polymer will have a density of >0.86 and it will show a Tg value greater than -25°C.The NMR spactra can also be used to charact- erize the pressure-sensitive adhesives of this inven¬ tion. For example, carbon-13 NMR spectra of operable propylene/1-hexene/l-octene copolymers determined in a mixture of o-dichlorobenzene and deuterobenzene as solvent and hexamethyldisiloxane as an internal standard shows a single peak at 12.2 ppm. and a multiplicity of peaks centered at about 19*7, 18.9 and 18.1 ppm. The single peak at about 12.2 ppm. is due to the presence of the methyl group in the side groups of the 1-hexene and 1-octene monomer units. The three sets of multi- plets are due to the methyl side groups of the propy¬ lene monomer units. There are three sets of mul iplets since there are triads of propylene monomer units pre¬ sent in all three possible types of stereoregular con¬ figurations (e.g., Ill or ddd triads, ddl or lid triads, and Idl or did triads). These new pressure-sensitive adhesive polymers appear to be multlblock copolymers of higher 1-ole in and propylene (or 1-butene or 1-pentene) wherein the propylene (or 1-butene or 1-pentene) blocks are partly stereoregular and partly heterotactic segments which are predominantly >20 monomer units long and wherein the higher 1-olefin blocks are incapable of crystallization at least over the temperature range of -20 to 180°F. We believe these substantially amorphous copolymers contain a very low order of polypropylene- type (or 1-butene type or 1-pentene type) crystallinlty which accounts for their good cohesive strength in pressure-sensitive adhesive applications.This structural interpretation of these co¬ polymers is in accord with the following measurable parameters: Density range, g./cc. 0.85-0.86Tg range, °C. (glass transition -30 to -45 temperature) Tm (crystalline melting point) No measurableTm by DSC-1B instrument. A weak endotherm at about 40-45°C. can sometimes be detected with DSC-2 instrument.The type of catalyst and the polymerization conditions required to provide such copolymers are quite limited. In general, the best results have been ach¬ ieved by using catalyst systems which provide poor stereo-regulation in the polymerization of propylene or 1-butene. Combinations of Et-,A1 with AATiCl., with Al/Ti molar ratios ranging from about 1:1 to 5:1 have been found to be useful. ' It is also generally desir¬ able to conduct the polymerization at relatively high temperatures such as from 140 to 170 C, preferably150°-l6θ°C., to provide copolymers having adequate pres¬ sure-sensitive adhesive properties.If catalysts which provide highly steroregu- lar propylene homopolymer are used to copolymerize propylene or 1-butene or 1-pentene, with hexene, heptene, octene, nonene, and decene, multiblock copolymers are often formed which contain crystallizable propylene or 1-butene or 1-pentene segments. Such copolymers usually have inadequate pressure-sensitive adhesive properties. Examples of highly stereospecific catalysts (for the polymerization of propylene) which provide these resultsOMPI include EtAlCl2/Bu3 /TiCl3, EtAlCl2/HPT/TiCl3, and EtgAlCl/ HPT/TiCl3 catalysts (Bu.N 3 tributyla ine; HPT = hexa- methylphosphoric triamide).Unmodified copolymers with melt viscosity greater than 75,000 cp are not generally useful as hot-melt, pres¬ sure-sensitive adhesives since they do not coat well on backing materials with currently available hot-melt coat- ers.The following test methods were used to evaluate the hot-melt, pressure-sensitive adhesives of this inven¬ tion.1. The melt viscosities of the adhesives were determined according to ASTM Procedure D1238.2. The glass transition temperatures of the ad- hesives were determined using a differential scanning calorimeter (Perkin-Elmer DSC-2 instru¬ ment) operating over the range of -70 C. to +200°C.3. The Ring and Ball softening points of the tackifying resins were determined according toASTM Procedure E28.4. The probe tack values of the coated tapes were determined according to the method as described by Testing Machines, Inc., A ityville, New York, the manufacturer of the Polyken Probe Tack Tester(Model TMIδO-2). The probe tack values were determined at 23°C. with the Polyken Probe Tack Tester using a 0.5 cm diameter probe, 100 g/cm contact pressure, two-second contact time, and 2 cm/second separation speed.5. The l8θ° peel adhesion values of the coated tapes were determined according to the Pressure Sensitive Tape Council's PSTC-1 test. The amount of adhesive residue left on the stainless steel testing panels when the bonds were tested was also noted. 6. The shear adhesion failure times of the coated tapes were determined according to the Pressure Sensitive Tape Council's PSTC-7 test.7. The bleed-through (staining) resistance of the adhesives was determined by coating the adhes¬ ives from the melt (190°C.) 0.001 to 0.002 inches thick on 60 pound Kromekote paper with a heated doctor blade. The coated paper tapes are then aged at 70°C. in a forced draft oven, and the degree of bleed-through on the paper backing was visually observed periodically up to four weeks.8. The thermal stabilities of the adhesives were de¬ termined by heating the adhesives to 177 C. in the presence of air for 24 hours in a Brookfield Thermosel viscometer. As a measure of thermal stability, the melt viscosities of the adhesives were determined with the viscometer at 177°C. after 1, 4, 8, 12 and 24 hours and differences from, the initial melt* viscosity were noted. Char and film formation were also noted.9. The compatibilities of the various base copoly¬ mers with the tackifying resins were determined by melting samples of each blend between glass microscope slides on a Mettler hot stage attach- ment for a microscope. The temperature of the melt was raised to 150°C, photomicrographs were made, and phase separation (if any) was noted. The following examples show the unpredlcted and surprising advantages obtained when compatible tackifying resins are used as modifiers according to this invention. For example, the addition of compatible tackifying resins to substantially amorphous olefin copolymers of and-olefin selected from propylene, 1-butene, and 1-pentene and a higher σ-olefin of 6 to 10 carbon atoms and having a melt viscosity greater than 75,000 cp at 190 C. causes an unex¬ pected increase in the shear failure time in addition totsTT EOMPI substantial increase in probe tack and peel adhesion values of the copolymers. It should be noted that the values ob¬ tained will depend somewhat on the degree of homogenization of the blend as well as on the thickness and smoothness of the polymer coating. Thus, the pressure-sensitive proper¬ ties of the blends of this invention may vary by as much as 10-25* depending on the blend method and on the quality of the coating.The pressure-sensitive adhesive compositions of this invention were prepared by blending together the two components in the melt at a temperature of l6θ°C. to 200°C. until a homogeneous blend was obtained. Various methods of blending materials of this type are known and any method that produces a homogeneous blend is satisfactory. These components blend easily in the melt and a heated vessel equipped with a stirrer is all that is required. For exam¬ ple, a Cowles stirrer provides an effective mixing means for preparing these hot-melt pressure-sensitive adhesive compositions. In addition to the copolymer and tackifying resin it is desirable for the hot-melt pressure-sensitive adhes¬ ive composition to contain 0.1 to about 1.5 percent by weight, preferably 0.25 percent to 1.0 percent by weight, of one or more stabilizers or antioxidants. Antioxidants that are effective for each of the various components can be used. Such antioxidants include, for example, Ionox 220 and 330 [tris(di-t-butyl-p-hydroxybenzyl)-trlmethyl- benzene], Dalpac 4C2 [2,6-di(t-butyl)-p-cresol], Nauga- white (alkylated bisphenol), Butyl Zimate (zinc dibutyl dithiocarba ate) and Ethyl 702 [4, '-methylene bis(2,β-di-tert-butylphenol)]. A particularly effective antioxidant is Irganox 1010 which is identified as pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxy- phenyl)propionate]. There are numerous uses for the pressure-sensi¬ tive hot-melt adhesives of the present invention. One such use is in the construction of women's sanitary napkins. A strip of the pressure-sensitive hot-melt adhesive may be applied to the polyethylene shield of the napkin and then protected by a release sheet. At the time of use, the re¬ lease sheet is removed and the napkin is held in place by adhering the pressure-sensitive hot-melt adhesive to the undergarment, thus eliminating the need for belts and pins. Removal of the napkin is quick as it strips cleanly from the garment.Another use of the pressure-sensitive hot-melt adhesives of this invention is in the construction of floor tiles having a preapplied adhesive for the do-it-yourself market. The pressure-sensitive hot-melt adhesive is thinly coated onto the undersurface of such floor tiles and cov¬ ered with a protective release sheet. Quick and permanent installation of the floor tiles is accomplished by removing the release sheet and pressing the tile into place. This technique of installing floor tiles can be extended to oth¬ er types of coverings such as wall tiles and ceiling tiles. Other major uses for the pressure-sensitive adhesives in- elude their use on tapes and labels.This invention can be further illustrated by the following examples. EXAMPLE 1Poly(48-propylene-co-52-[l-hexene]) [30g; 100,000 cp at 190°C. by ASTM D1238; Tg - 31°C], 10 g of Wingtack 95 tackifying resin (a synthetic polyterpene hydrocarbon type tackifying resin based on a Cj- olefin fraction; Ring and Ball softening point = 100+5°C, iodine number = 30, specific gravity = 0.93); and 0.1 g of Irganox 1010 anti- oxidant (pentaerythritol tetrakis[3-(3,5-ditertbutyl-4- hydroxyphenyDpropionate]) were melt blended at 170 C. for 30 minutes under an atmosphere of nitrogen. The clear com¬ patible blend was removed from the mixer and allowed to cool to 23°C. At 23°C, the blend was very tacky to the touch. The melt viscosity of the blend was 31,800 cp at 190°C. The blend had a glass transition temperature (Tg)_ OMPl of -20UC .A sample of the blend was maintained at 177 C. for 24 hours in contact with air. The sample did not change in melt viscosity during this period and it did not show any evidence of char formation or film formation on the surface of the melt.The blend was coated from the melt (190°C.) 0.001 +0.0002 inch thick onto Mylar film (0.001 inch thick) using a heated doctor blade. The resulting pressure-sensitive Q tapes were transparent and had a probe tack value of 1139 g/0.5 cm diameter probe and a 180 peel adhesion value of 4.2 pounds/inch-width after the tapes were aged for 24 hours at 23°C. and 0? relative humidity. No adhesive res¬ idue was left when the coated tapes were 'peeled from the 5 stainless steel test panels. The tapes had shear adhesion failure times of greater than 10,000 minutes when using a 1000 g static load per square inch of bond area. The probe tack and l8θ peel adhesion values were not changed when the tapes were aged for one week at 50 C. Coated tapes 0 made using 60 pound Kromekote paper were aged in an oven at 70 C. for four weeks. These aged paper tapes showed no evidence of bleed-through. Similarly good results were achieved using Wingtack 115 tackifying resin (Ring and 3all softening point = 115-120°C, molecular weight = 1400 to 5 1500) Instead of Wingtack 95.The unmodified poly(48-propylene-co-52-[l-hexene]) had a probe tack value of 04 g/0.5 cm diameter probe, a l8θ° peel adhesion value of 3-7 pounds/inch-width, and a shear adhesion failure time of 6476 minutes. 0 EXAMPLE 2The procedure of Example 1 was repeated except that 38 g of pol (48-propylene-co-52-[l-hexene]) having a melt viscosity of 100,000 cp at 190°C. was blended with 2 g of Wingtack 95 to prepare a blend having a melt viscosity 5 of 72,000 cp at 190°C. Pressure-sensitive tapes made with this blend had a probe tack value of 7 7 g/0.5 cm diameter probe, a peel adhesion value of 3.9 pounds/inch, and a adhesion failure time of 8250 minutes. EXAMPLE 3<■ The procedure of Example 1 was repeated except that 3^ g of poly(50-propylene-co-50-[l-hexene]) having a melt viscosity of 240,000 cp at 190°C. was melt blended wit 6 g of Wingtack 95 resin to provide a blend with a melt viscosity of 110,000 cp at 190°C. This blend was compatible and pressure-sensitive tapes made with this blend had a . probe tack value of 810 g/0.5 cm diameter probe, a peel adhesion value of 3-3 pounds/inch, and a shear adhesion failure time of greater than 10,000 minutes. EXAMPLE 4The procedure of Example 1 was repeated except that 26 g of poly(50-propylene-co-50-[l-hexene]) having a melt viscosity of 240,000 cp at 190°C. was melt blended with 14 g of Wingtack 95 resin to provide a blend with a melt viscosity of 42,000 cp at 190°C. This blend was com¬ patible and coated tapes had a probe tack value of 903 g/0.5 cm diameter probe, peel adhesion value of 4.3 pounds/ inch, and a shear adhesion failure time of greater than 10,000 minutes. EXAMPLE 5The procedure of Example 1 was repeated except that 20 g of a poly(50-propylene-co-50-[l-hexene]) having a melt viscosity of 821,000 cp at 190°C. was blended with 20 g of Wingtack 95 resin to provide a blend having a melt viscosity of 150,000 cp at 190°C. The blend was permanently tacky and coated tapes had a shear adhesion failure time of greater than 10,000 minutes. EXAMPLE 6The procedure of Example 1 was repeated except that 20 g of poly(50-propylene-co-50-[l-hexene]) having a melt viscosity of 1,000,000 cp at 190°C. was blended with 20 g of Wingtack 95 resin to provide a blend having a melt viscosity of 182,000 cp at 190°C. Pressure-sensitive tapes made with this blend were permanently tacky and has a shear adhesion failure time of greater than 10,000 minutes.Because of the very high melt viscosity of the unmodified copolymer, pressure-sensitive tapes could not be made using the unmodified copolymer. EXAMPLE 7The procedure of Example 1 was repeated except that 30 E of poly(50-propylene-co-50-£l-hexene]) having a melt viscosity of 76,000 cp at 190°C. was blended with 10 g of Wingtack 95 resin to provide a blend having a melt viscosity of 24,500 cp at 190°C. Pressure-sensitive tapes made with this blend had a probe tack value of 1070 g/0.5 cm diameter probe, a peel adhesion value of 4.4 pounds/ inch, and a shear adhesion failure time of greater than 10,000 minutes. The unmodified poly(50-propylene-co-50-[l-hex- ene]) had a probe tack value of 560 g/0.5 cm diameter probe, a peel adhesion value of 3-2 pounds/inch, and a shear adhesion failure time of 5,560 minutes. EXAMPLE 8 The procedure of Example 1 was repeated except that 30 g of poly(59-propylene-co-4l-[l-hexene]) having a melt viscosity of 90,000 cp at 190°C. was blended with 10 g of Zonarez 7100 resin (a polyterpene type tackifying resin; Ring and Ball softening point = 100°C.) [ASTM E28-67, color 3 (Gardner 1963, 50? in heptane) and specific gravity at 25°C. of 0.97 (ASTM D1963-61)] to provide a blend having a melt viscosity of 28,700 cp at 190°C. Pres¬ sure-sensitive tapes made with this blend had a probe tack value of 1090 g/0.5 cm diameter probe, a peel adhesion val- ue of 4.9 pounds/inch, and a shear adhesion failure time of greater than 10,000 minutes. EXAMPLE 9The procedure of Example 1 was repeated except that 30 g of poly(42-propylene-co-58-[l-hexeneJ) having a melt viscosity of 108,000 cp at 190°C. was blended with 10 g of Eastman resin H-100 tackifying resin (a DAC-B hydrbcarbon type tackifying resin; Ring and Ball softening point » 10Q°C.) to provide a blend having a melt viscosity of 36,000 cp at 190°C. Pressure-sensitive tapes made with this blend had a probe tack value of 1120 g/0.5 cm diameter probe, a peel adhesion value of 4.5 pounds/inch, and a shear adhesion failure time of 7,500 minutes. EXAMPLE 10The procedure of Example 1 was repeated except that a 30 g of poly(50-propylene-co-9-[l-butene]-co-4l- [1-hexene]) having a melt viscosity of 105,000 cp at190°C. was blended with 10 g of Wingtack 95 resin to pro¬ vide a blend having a melt viscosity of 32,800 cp at 190 C. Pressure-sensitive tapes made with this blend had a probe tack value of 1210 g/0.5 cm diameter probe, a peel adhesion value of 4.8 pounds/inch, and a shear adhesion failure time of 8,350 minutes. EXAMPLE 11The procedure of Example 1 was repeated except that 30 g of poly(50-[l-butene3-co-50-[l-hexene]) having' a melt viscosity of 125,000 cp at 190°C. is blended with 10 g of Wingtack 95 resin to provide a blend having a melt viscosity of 39,^00 cp at 190°C.Pressure-sensitive tapes made with this blend had a probe tack value of 1300 g/0.5 cm diameter probe, a peel adhesion value of 5.1 pounds/inch, and a shear adhesion failure time of 200 minutes.The unmodified poly(50-[l-butene]-co-50-[l-hex- ene]) had a probe tack value of 790 g/0.5 cm diameter probe, a peel adhesion value of 3.7 pounds/inch, and a shear adhesion failure time of 85 minutes. EXAMPLE 12The procedure of Example 1 was repeated except that 30 S of poly(50[l-pentene]-co-50-l-hexene]) having a melt viscosity of 87,000 cp at 190°C. was blended with 10 S of Wingtack 95 reβin to provide a blend having a melt viscosity of 29,500 cp at 190°C. Pressure-sensitive tape made with this blend had a probe tack value of 1245 g/0.5O PI W1PO cm di&meter probe, a peel adhesion value of 4.9 pounds/ inch, and a shear adhesion failure time of 180 minutes. # The unmodified poly(50-£l-ρentene]-co-50-[l-• hexene]) had a probe tack value of 780 g/0.5 cm diameter c probe, a peel adhesion value of 3*5 pounds/inch, and a shear adhesion failure time of 70 minutes. EXAMPLE 13The procedure of Example 1 was repeated except that 30 g of poly(30-propylene-co-10-[l-butene]-co-10-10 [l-pentene]-co-50-[l-hexene]) having a melt viscosity of 350,000 cp at 190°C. was blended with 10 g of Wingtack 95 resin to provide a blend having a melt viscosity of 109,000 cp at 190 C. Pressure-sensitive tapes made with this blend had a probe tack vlaue of 1190 g/0.5 cm diameter probe, a15 peel adhesio 'value of 5.4 pounds/inch, and a shear adhe¬ sion failure time of 6,210 minutes. EXAMPLE 14The procedure of Example 1 was repeated except that 30 g of poly(55-propylene-co-25-[l-hexene]-co-20-20 [1-octene]) having a melt viscosity of 270,000 cp at 190°C. was blended with 10 g of Wingtack 95 resin to provide a blend having a melt viscosity of 79,000 cp at 190°C. Pres¬ sure-sensitive tapes made with this blend had a probe tack value of 1330 g/0.5 cm diameter probe, a peel adhesion25 value of 4.3 pounds/inch, and a shear adhesion failure time of 2,200 minutes.The unmodified poly(55-propylene-co-25-[l-hexene] -co-20-[l-octene]) had a probe tack value of 580 g/0.5 cm diameter probe, a peel adhesion value of 3*1 pounds/inch,30 and a shear adhesion failure time of 1,025 minutes. EXAMPLE 15The procedure of Example 1 was repeated except that 30 g of poly(55-propylene-co-20-£l-hexene]-co-15- [l-octene3-co-10-[l-decene]) having a melt viscosity of 35192,000 cp at 190°C. was blended with 10 g of Wingtack 95 resin to provide a blend having a melt viscosity of 63,000 cp at 190 C. Pressure-sensitive tapes made with this blend had a probe tack value of 1210 g/0.5 cm diameter probe, a peel adhesion value of 4.6 pounds/inch, and a shear ad¬ hesion failure time of 1640 minutes.The unmodified poly(55-propylene-co-20-£l-hexenej -co-15-£l-octene]-co-10-£l-decenej) had a probe tack value of 710 g/0.5 cm diameter probe, a peel adhesion value of 3.4 pounds/inch, and shear adhesion failure time of 750 minutes. EXAMPLE 16 The procedure of Example 1 was repeated except that 30 g of poly(50-propylene-co-25-£l-hexeneJ-co-25- £l-heptenej) having a melt viscosity of 82,000 cp at 190°C. was blended with 10 g of Wingtack 95 resin to provide a blend having a melt viscosity of 26,100 cp at 190°C. Pres- sure-sensitive tapes made with this blend had a probe tack value of 1115 g/0.5 cm diameter probe, a peel adhesion val¬ ue of 4.2 pounds/inch, and a shear adhesion failure time of 9,670 minutes.The unmodified poly(50-propylene-co-25-£l-hexene] -co-25-£l-heptene]) had a probe tack value of 735 g/0.5 cm diameter probe, a peel adhesion value of 3.5 pounds/inch, and a shear adhesion failure time of 4,950 minutes.The following examples (Examples 17 and 18) show that incompatible tackifying resins are not operable in the practice of this invention. For example, the addition of incompatible tackifying resins such as Foral 105 resin (a wood rosin ester tackifying resin and Picco 6100 (a polyindene type tackifying resin) to the olefin copolymers caused the coatings to be grainy and hazy and reduced the probe tack values of the blends to such a low level that they were no longer useful as pressure-sensitive adhesives. EXAMPLE 17The procedure of Example 1 was repeated except that 30 g of poly(.48-propylene-co-52-£l-hexene]) having a melt viscosity of 100,000 cp at 190°C. was blended with 10 K of Picco 6100 resin (a polyindene type tackifyingOMPI * resin; Ring and Ball softening point * 1Q0°C.) to provide a blend having a melt viscosity of 45,000 cp at 190°C. Pressure-sensitive tapes made with this blend had a probe tack value of 180 g/0.5 cm diameter probe. EXAMPLE 18The procedure of Example 1 was repeated except that 30 g of poly(50-propylene-co-9-£l-butene]-co-4l-£l- hexene]) having a melt viscosity of 105*000 cp at 190°C, was blended with 10 g of Foral 105 resin (a pentaerythri- tol ester of hydrogenated rosin; Ring and Ball softening point = 105 C.) to provide a blend having a melt viscosity of 39*500 cp at 190°C Pressure-sensitive tapes made with this blend had a probe tack value of 265 g/0.5 cm diameter- probe. | We Claim:1. An adhesive composition capable of being used as a hot-melt, pressure-sensitive adhesive characterized by a blend of (1) 95 to 50 weight percent of a substantially amor¬ phous olefin copolymer containing a C-, to C_- linear alpha-olefin and 40 to 60 mole percent of a higher alpha-olefin of 6 to 10 carbon atoms, said copolymer having a melt viscosity greater 0 than 75,000 to 1,000,000 centipoise at 190°C, and (2) 5 to 50 weight percent of a compatible tackify- . ing resin.2. An adhesive composition according to Claim 1 _c wherein the compatible tackifying resin is a hydrocarbon tackifying resin.3. An adhesive composition capable of being used as a hot-melt, pressure-sensitive adhesive characterized by a blend of 0 (1) 90 to 60 weight percent of a substantially amor¬ phous copolymer containing a C-, to C_- linear alphaolefin and 40 to 60 mole percent of a higher alpha-olefin of 6 to 10 carbon atoms, said copolymer having a melt viscosity greater 5 than 75,000 to 1,000,000 centipoise at 190°C, and (2) 10 to 40 weight percent of a compatible hydro¬ carbon tackifying resin.4. An adhesive composition according to Claim 3 Q wherein said compatible hydrocarbon tackifying resin is a polyterpene resin.5. An adhesive composition according to Claim 3 wherein the hydrocarbon tackifying resin has a Ring and Ball softening point of from 8θ°C. to 130°C, an acid num- 5 ber of from 0-2, a saponification value of less than 1, and iodine value of from 30 to 10Q. 6. An adhesive composition according to Claim 5 wherein said hydrocarbon tackifying resin is DAC-B hdyro- carbon,resin. | EASTMAN KODAK CO | JOYNER F; MCCONNELL R; TROTTER J |
WO-1979000285-A1 | 1,979,000,285 | WO | A1 | EN | 19,790,531 | 1,979 | 20,090,507 | new | B24B13 | null | B24B13 | B24B 13/02 | MACHINE FOR SMOOTHING AND/OR POLISHING LENS FACES | A machine for smoothing and/or polishing lenses has a holder (8) which is carried on a slide (24). The slide is guided for movement in two mutually perpendicular directions, both of which are perpendicular to a main axis (27) of the machine. The slide is moved in a plane perpendicular to the main axis along a curved path which results from the combination of two orbital motions produced by cams (32, 35). One cam (32) is secured to the main shaft (28) and rotary motion is transmitted to the other cam (35) by an element (33) which rotates about the axis of the main shaft and is driven from the main shaft through a transmission means which has a velocity differing from unity. | Title: Machine for smoothing and/or polishing lens faces THIS INVENTION relates to a machine for smoothing and/or polishing a non-spherical curved face of a lens, which -face has a different curvature at different angular positions about an optical axis of the lens. Such a face is referred to herein and in the art as a cylindrical face but it will be understood that the term embraces forms which cannot be generated by the rotation about an axis of a straight line which is parallel to that axis. Background art:To smooth and polish a cylindrical lens face, the face is rubbed on a layer of an abrasive on. a complementary face of a tool. Relative movement of respective reference axes of the lens and tool must be controlled to avoid changing the curvature of the face of the lens and the relative movement must change throughout the operation to avoid the formation of marks on the face of the lens.Known machines for smoothing and polishing cylindrical faces of lenses have complex driving means for moving one of the tool' and the lens relative to the other in a manner such that the locus of a point on the lens relative to a point on the tool shows little regularity. These known driving arrangements cause abrupt changes of direction of the tool or lens and elements of the driving means undergo rapid changes in velocity. These elements must be robust and accordingly are fairly massive. During operation, the known machines are subjected to severe vibration which is accompanied by excessive noise and by deterioration of the machine. The inertia of moving parts results in variations between the pressure under which the tool contacts the lens at different places on the face of the lens and these variations in pressure result in changes in the curvature of the lens face. A further disadvantage of the known machines is that the driving means is not capable of controlling relative movement of the reference axes of the tool and lens sufficiently accurately. Inaccuracy in such control also leads to changes in the curvature of the lens face.Disclosure of the Invention:According to a first aspect of the invention, there is provided a machine for smoothing and/or polishing lenses comprising at least one pair of relatively movable holders arranged for holding respective ones of a tool and the workpiece which are to be rubbed together by relative movement of the holders, constraining means for maintaining respective reference axes of the holders parallel to a reference plane and driving means for causing said relative movement of the holders wherein the constraining means comprises a first slide, means for guiding the first slide along a first rectilinear path relative to a body of the machine, a second slide and means for guiding the second slide along a second rectilinear path relative to the first slide, the second path being transverse to the first path.Preferably, said paths are perpendicular to each other.According to a second aspect of the invention, there is provided a machine for smoothing and/or polishing lenses comprising at least one pair of relatively movableO holders arranged for holding respective ones of a tool and a workpiece which are to be rubbed together by relative movement of the holders, constraining mea_ns for maintaining respective reference axes of the holders parallel to a reference plane and driving means for causing said relative movement of the holders, wherein the driving means comprises first and second elements which are rotatable about a main axis at respective different speeds, the first element defining an auxiliary axis offset from the main axis to move around the main axis when the first element rotates and an output element mounted for rotation about the auxiliary axis, the second element being so associated with the output element as to move the output element around the auxiliary axis when the second element moves around the main axis.The main axis may be fixed with respect to a body of the machine and there may be provided means for connecting one of the holders with the output element for displacement therewith relative to the main axis.The other holder may occupy a fixed position with respect to the main axis and the body of the machine.There may be provided coupling means for coupling the second element to the output element, the coupling means being adapted for transmitting rotary drive from the second element to the output element and for accommodating relative displacement of the second element and output element radially of the axis about which one of these elements rotates.The coupling means may comprise a roller which is movable along a slot.The driving means may include transmission means for transmitting rotary motion between^the first element and the second element with a velocity ratio other than unit .There may be provided a main shaft on which the first element is secured and the transmission means may comprise a lay shaft which is driven from the main shaft and from which drive is transmitted to the second element.The lay shaft axis is preferably fixed with respect to the main axis.Brief description of the drawings:One example of an embodiment of the invention will now be described, with reference to the accompanying drawings, wherein:-FIGURE 1 shows diagrammatically a side elevation of a machine for smoothing and/or polishing a lens face,FIGURE 2 shows diagrammatically .a cross section of certain parts of the machine on the line 2-2 of Figure 1,FIGURE 3 shows diagrammatically a cross section of further parts of the machine on the line 3-3 of Figure 1, andFIGURE shows a cross section of the parts shown in Figure 2 in a plane containing a main axis of the machine.The- machine comprises a body 1 which remains stationary during operation of the machine and may stand on a bench so that the machine is at a convenient height for loading lenses and tools into the machine. On the body, there is provided a vice 2 for holding one of a lens and a tool which are to be rubbed together. In the particular example shown, a smoothing or polishing tool 3 is clamped in the vice and is held thereby in a fixed position relative to the body 1. The vice can be opened by means of a hand wheel 4 for substitution of the tool 3 by a different tool.On an upwardly facing convex face of the tool 3* there rests a lens having a downwardly facing, concave face which is to be smoothed or polished. On the surface of the lens remote from the tool, there is a metal pallet 6 to which the lens is secured, for example by pitch or by a low-melting point alloy. In an upwardly facing surface of the pallet 6, there are formed two recesses in which there engage a pair of spigots 7- The spigots are provided on a lens holder 8 which is supported on one end of a lever 9 for pivoting movement rel ative to the lever about a horizontal axis 10 which extends from front to rear of the machine. The lens holder may take various know forms, one of which is that of a yoke.The lever 9 is supported for pivoting about a horizontal axis 11 which is perpendicular to the axis 10. For urging the lens 5 towards the tool 3 and establishing a predetermined pressure at the interface between the lens and tool, there is provided a piston and cylinder unit whereof the piston 12 is connected through the intermediary of a universal joint 13 with an end of the lever 9 remote from the lens holder 8. The cylinder 1 of the unit is connected at its end remote from the lever 9 with the body 1 through the intermediary of a further universal joint 15.The machine further comprises driving means for causing movement of the lens holder 8 relative to the body 1 and the tool in horizontal directions to rub the faces of the lens and tool together, and constrain¬ ing means for maintaining respective reference axes l6 and 17 of the vice 2 and lens holder 8 parallel to a reference plane. This reference plane is parallel to the opposed surfaces of the jaws of the vice 2 between which the tool 3 is gripped and contains the reference axis of the vice.The constraining means comprises a set of first slides 18 to 21 and a pair of rectilinear bars 22 and 23 for guiding the first slides along respective rectilinear paths relative to the body 1. The bars 22 and 23 are parallel to each other, are secured to the body 1 and are arranged with their lengths extending from fro3it to rear of the machine. The slides 18 and 19 are slidable along the bar 22 and the bars 20 and 21 are slidable along the bar 23.The constraining means further comprises a second slide 2 and a pair of rectilinear bars 2 and 26 for guiding the second slide along a rectilinear path trans- verse to the bars 22 and 23. In the particular example shown, the bars 25 and 26 are perpendicular to the bars 22 and 23. Each of these bar's is perpendicular to a main axis 27 of the machine which extends in the same general direction as that in which the vice 2 and lens holder 8 are spaced apart. The bars 5 and 26 are carried by the first slides 18* to 21 for movement there¬ with. Opposite end portions of the bar 2 are secured in respective apertures in the slides 18 and 20 and opposite end portions of the bar 26 are secured in respective apertures in the slides 19 and 21. The bars 25 and 26 extend through respective apertures in the second slide 24 with a sliding fit. The slide 24 is thus constrained against turning about any axis relative to the body 1 but is free to undergo limited movement relative to the body in all directions perpendicular to the main axis 2 .The pivot by which the lever 9 s supported for pivoting about the axis 11 is carried by and is fixed with respect to the second slide 24 so that the lever 9 can turn relative to the body 1 only about the axis 11 and the lens holder 8 can turn relative to the body only about the axes 10 and 11 which are perpendicular to each other and to the main axis 27. The lens 5 is constrained against turning about the- main axis 27 or any axis parallel thereto.The driving means comprises a main shaft 28 which is supported in bearings 29 on the body 1 for rotation about the main axis 27, the latter being fixed with respect to the body. For driving the main shaft, there is provided a motor 30 having an output shaft which is connected with the main shaft by a belt and pulley drive 31. On the main shaft, there is carried a first element in the form of a cam 2 which is keyed to the shaft for ro¬ tation therewith about the main axis 2 and a second element in the form of a pulley 33 which is rotatable about the main axis 27 independently of the main shaft 28.The periphery of the cam 32 is eccentric with respect to the main axis 2 and defines an auxiliary axis 3^- offset from the main axis. An output element in the form of .a cam 35 is arranged to rotate about the auxiliary axis, running on the periphery of the first cam 3 . Preferably, a ball bearing is interposed between the cams 32 and 35 but this bearing has been omitted from the drawing for clarity of illustration. For transmitting displacement of the output cam 35 to the second slide 24, there is provided a ring 36 which is secured to the second slide and runs on the output cam. Again, a ball bearing is preferably interposed between the cam 35 and the ring 3 but this bearing has been omitted from the drawing for clarity. The interface between the output cam 35 and the ring 36 is eccentric with respect to the auxiliary axis 34. Accordingly, if the output cam 35 is turned about the auxiliary axis it causes the ring 36 and the second slide 24 to be* displaced along a circular path relative to the auxiliary axis-For turning the output cam 35 about the auxiliary axis, there is provided transmission means for transmitting rotary motion from the main shaft 28 to the pulley 33 and coupling means for transmitting that motion from the pulley to the output cam. The coupling means couples the output cam and pulley 33 together for rotary motion but is adapted to accommodate relative displacement of the pulley and output cam radially of the auxiliary axis 34. In the pulley 33. there is formed a radially extending track 50 in which there is engaged a roller 37. The roller is carried on a spindle 38 secured to the output cam 35. If the pulley is rotated about the main axis 27. the roller 37 s carried around that axis and so turns the output cam about the auxiliary axis 3 , the roller moving along the track in the pulley towards and away from the auxiliary axis to accommodate the eccentricity of the axes.The transmission means comprises a lay shaft 39 supported by bearings 40 on the body 1 for rotation about an axis which is fixed relative to the body and is parallel to the main axis 27. A belt and pulley drive 42 is provided for transmitting drive from the main shaft 28 to the lay shaft and a further belt and pulley.drive 43 is provided for transmitting rotary drive from the lay shaft to the pulley 33• It will be noted that the pulleys of the drives 31» 42 and 43 each rotates about a respectiveOM axis which is fixed relative to the body 1 so that there is no variation in the tension of the drive belts during operation of the machine.The respective velocity ratios of the belt and 5 pulley drives 42 and 43 are such that the overall velocity ratio of the transmission means differs from unity. The speed of rotation of the pulley 33 is less than that of the first cam 32. We have found that a transmission means having a velocity ratio of 4l6:19 gives satisfactory 10 results.As the main shaft 28 rotates, the auxiliary axis34 is carried around the main axis 27 by the first cam 32. This motion is transmitted through the output cam35 to the ring 6 and the second slide 24. An additional, 15 but slower, rotary motion is applied to the ring 36 and slide 24 by rotation of the output cam 35 about the auxiliary axis 34. in the manner previously described. The motion of the slide 24 is therefore the resultant of combining two circular motions of different frequency20 and the lens holder 8 executes a corresponding motion relative to the vice 2. Because the motion is produced by combining continuous rotary motions, neither any element of the driving means nor the lens 5 s subjected to abrupt changes of direction or rapid changes in•25 velocity.A further advantage provided by the fundamentally rotary motion produced by the machine described, as compared with the fundamentally reciprocating motions provided in known machines, is that a greater degree 30 of rubbing is produced by a circular motion of given throw than is produced by a reciprocating motion of the same throw. This enables a relatively small throw to be used in the machine described and this enables proper contact to be maintained between the lens and tool with rocking of the lens about the axis 10 and rocking of the lens about an axis defined by the spigots 7 through only relatively small angles.If a single machine is to be used on different occasions for smoothing and for polishing lenses, then we prefer that the eccentricity of the first cam 32 and the eccentricity of the output cam 35 should be adjustableβ We have found that good results are achieved if, for smoothing, the eccentricity of the first cam 32 is 33 m and the eccentricity of the output cam 35 is 10 mm. For polishing, we have found that a first cam with an eccentricity of 57 mm and an output cam with an eccen¬ tricity of 10 mm provides good results.To enable the eccentricity of the first cam 32 to be adjusted, this cam is formed in two parts, namely an inner part 44 and an outer part 45. The inner part 44 is keyed to the main shaft 28 and the outer part 45 s releasably clamped to the inner part by a clamping screw 46. 'When the clamping screw is slackened, the outer part can be adjusted relative to the inner part about an axis which is offset from the main axis 27 to adjust the eccentricity of the periphery of the first cam relative to the main axis.Similarly, the output cam 35 formed in two parts, namely a lower part 47 and an upper part 48. The lower part 47 runs on the first cam 3 and carries the spindle 38. The ring 36 runs on the upper part 48 and the parts 47 and 48 are releasably clamped together by a clamping screw 49* When the clamping screw is slackened, the eccentricity of the ring 6 with respect to the auxiliary- axis 34 can be adjusted. The range of adjustment of theOM cai s 32 and 35 s limited by the respective forms of the components of these cams so that it is not possible to set the machine in a condition in which a moving part of the machine will foul some other part of the machine during operation.Industrial applicability:The driving means and constraining means of the machine combine to cause the lens 5 to move smoothly relative to the tool 3 along a curved path which has no abrupt changes of direction, brings about a relatively large amount of rubbing contact between all parts of the lens face and the tool and controls the relative movement so that the reference axis 17 of the lens is maintained in the reference plane containing the reference axis l6 of the tool. Although the machine is especially useful for smoothing and polishing cylindrical faces of lenses, both convex and concave faces, the machine is also useful for smoothing and polishing part-spherical faces of lenses.As in known machines for smoothing and polishing lenses, there may be provided means for feeding a slurry of abrasive particles in a liquid coolant to the inter¬ face between the lens 5 and the tool 3 and there may further be provided a housing in which the vice 2, tool 3 lens 5 and lens holder 8 are disposed. Such housing would prevent the abrasive slurry being thrown away from the machine and would enable the slurry to be collected and re-used in a known manner. Since the housing and slurry feed means form no part of the present invention, they have been omitted from the accompanying drawings and will not be more particularly described. | Claims :1. A machine for smoothing and/or polishing lenses comprising at least one pair of relatively movable holders (2, 8) arranged for holding respective ones of a tool (3) and a workpiece (5) which are to be rubbed together by relative movement of the holders, constraining means for maintaining respective reference axes (l6, 17) of the holders parallel to a reference plane and driving means for causing said relative movement of the holders characterised in that the constraining means comprises a first slide (l8 -2l) , means (22, 23) for guiding the first slide along a first rectilinear path relative to a body (l) of the machine, a second (24) slide and means (25, 26) for guiding the second slide along a second rectilinear path relative to the first slide, the second path being transverse to the first path.2. A machine according to claim 1 further characterised in that the first path is perpendicular to the second path.3 - A machine according to claim 1 or claim 2 further characterised in that the means for guiding the first slide comprises at least one rectilinear element (22, 23) * along which the first slide is slidable and in that the means for guiding the second slide comprises at least one further rectilinear element (25, 26) along which the second slide is slidable.4. A machine according to any preceding claim further characterised in that the first and second paths are both perpendicular to an axis (27) of the machine.5. A machine for smoothing and/or polishing lenses comprising at least one pair of relatively movable holders (2, 8) arranged for holding respective onesOM - of a tool (3) and a workpiece (5) which are to be rubbed together by relative movement of the holders, constraining means for maintaining respective reference axes (l6, 17) of the holders parallel to a reference plane and driving means for causing said relative movement of the holders characterised in that the driving means comprises first and second elements (32, 33) which are rotatable about a main axis (27) at respective different speeds, the first element defining an auxiliary axis (34) offset from the main axis (27) to move around the main axis when the first element rotates and an output element (35) mounted for rotation about the auxiliary axis (34), .the second element (33) being so associated with the output element (35) as to move the output element around the auxiliary axis when the second element moves around the main axis.6. A machine according to claim 5 further characterised in that the main axis (27) is fixed with respect to a body (l) of the machine and there is provided means (36, 24, 9) connecting one of the holders (8) with the output element (35) for displacement therewith relative to the main axis.7. A machine according to claim 5 Q1~ claim 6 further characterised by means (37. 38) for coupling the second element (33) to the output element (35)j the coupling means being adapted for transmitting rotary drive from the second element to the output element and for accommodating relative displacement of the second element and the output element radially of the auxiliary axis (34).8. A machine according to claim 7 further characterised in that the coupling means comprises a roller (37) movable along a slot (50). 9. A machine according to any one of claims 6 to 8 further characterised by the provision of transmission means (39. 42, 43) for transmitting rotary motion from the first element (3 ) to the second element (33) with a velocity ratio differing from unity.10. A machine according to claim 9 further characterised by a main shaft (28) on which the first element (32) is secured and by a lay shaft (39) comprised by the trans¬ mission means, there being provided first drive means (42) for transmitting rotary drive from the main shaft to the lay shaft and second drive means (43) for trans¬ mitting rotary drive from the lay shaft to the second element (33).11. A machine according to claim 10 further characterised in that the lay shaft is supported by bearings (40) for rotation about an axis which is fixed with respect to the axis (27) of the main shaft (28).12. A machine according to any one of claims 5 to 11 further characterised in that the constraining means comprises a first slide (l8-2l), means (22, 23) for guiding the first slide along a first rectilinear path relative to the body 1 of the machine, a second slide (24) and means (25, 26) for guiding the second .slide along a second rectilinear path relative to the first slide, the second path being transverse to the first path.13. A machine according to claim 12 further characterised in that said first and second paths are each perpendicular to the main axis (27).OMPI | DOLLOND AITCHISON SERVICE; EADON ALLEN S; DOLLOND & AITCHISON SERVICES LTD | EADON ALLEN S |
WO-1979000286-A1 | 1,979,000,286 | WO | A1 | EN | 19,790,531 | 1,979 | 20,090,507 | new | E04F17 | F01N7, F01N1 | F01N1, F02C7, F16L9, F16L55, F24F13 | F01N 1/00B, F01N 1/02, F02C 7/045, F16L 55/027J, F16L 9/21, F24F 13/24, R01N 1/00B1, R01N 490/15B | PACKLESS SILENCER | The acoustical gas flow silencer field, e.g. heating, ventilating and air conditioning systems, engine intakes and exhausts, process blowers and compressors, etc. In the prior art, silencers were constructed using an absorbtive material, which was both expensive and inefficient. The device described herein is a packless silencer, and accomplishes the desired end of dampening undesired noise in a manner both more economical and efficient than heretofore known. The invention described is a resistive sheet type of duct liner or duct silencer, i.e., a liner or silencer in which acoustical flow resistance is concentrated in a thin face sheet (14a) separating the flow passage and acoustical cavity (16) the invention disclosed is a means for applying inexpensive perforated facings (14) and (14a) similar to those in a conventional packed silencer, to provide resistive sheets which are effective in terms of noise dissipation and in terms of self-noise (noise generated by flow through the flow passages).@00 | BACKGROUND OF THE INVENTIONConventional silencer* of the type in which the silencer is inserted into the flow of gas to attenuate noiae traveling in thegas stream have generally relied upon viscous friction in the pores of a cavity filler material.A conventional silencer typically includes a duct member within which is positioned one or more silen¬ cer elements consisting of a perforated facing plate be¬ hind which is positioned a filler material, βuch as foam, rockwool, fiberglass or other fibrous acoustically absorb- tive bulk material. The filler may be referred to as packing.Because these packed duct silencers rely on absorption by the packing, the perforated facing sheet ia designed to provide optimum sound access from the flow passage to the packing material. Face sheet open face area in these silencers are typically 207. and more. The use of packing to absorb acoustical noise introduces problems in many applications. The packing tends to erode under high velocity conditions; the pack¬ ing may absorb toxic or flammable substances or micro¬ organisms; the packing is subject to attack by chemicals; and in the event of fire, some otherwise desirable pack¬ ings may provide fuel or produce toxic gases. It has been known for nearly thirty years that, by using face sheets with suitable acoustic flow resis¬ tance in lieu of conventional perforated face sheets, broad band acoustical absorption could be obtained with¬ out the use of packing. In order to overcome packing problems, silen¬ cers have been designed in which the required acoustic resistance was provided by thin resistive sheets rather than by packing. The resistive sheets of these con¬ structions have been structually self-supporting sintered materials or laminates of fabrics (metals, glass or syn- thetic), felts (metal, synthetic or organic) or sintered materials (metal or ceramics) - typically supported on a structural perforated sheet. These silencers have found very limited use due to their high cost. SUMMARY OF THE INVENTIONThe present invention overcomes the shortcom¬ ings of the prior art by making use of a commercially available perforated face sheet having an open area in the range of 2 to 107. to provide suitable acoustic flow resistance which is enhanced by the flow present in the silencer passages as a normal consequence of its use.By proper choice of perforation geometry in a thin sheet of stainless, cold rolled, galvanized steel, aluminum or other metallic or synthetic material, broad band noise dissipation of a useful magnitude can be ob¬ tained without the use of packing and without generating unacceptable levels of self-noise.DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view illustrating a packless acoustic silencer of the present invention;Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1;Figure 3 is a cross-sectional view illustrating a series arrangement of silencers in accordance with the present invention;Figure 4 is a cross-sectional view of a silencer of Figure 1 joined with a silencer of the same type, but with cavity depth chosen to enhance performance at a higher frequency;Figure 5 is a cross-sectional view of two silen-OM.A < . cers of Figure 4 joined by a transition member designed to reduce restriction to air flow while further supple¬ menting high frequency performance;Figure 6 is a cross-sectional view of two silen- cere of Figure 1 joined by a transition member with a splitter;Figure 7 is a cross-sectional view of a triple tuned silencer in which each of three modules provides broad band performance but each of which is tuned for peak performance at a different frequency; andFigures 8-11 are graphs of various silencer performance correlations as function of octave band fre¬ quency.DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT While this invention is susceptible of embodi¬ ment in many different forms , there is shown in the draw¬ ings and will hereinafter be described in detail a pre¬ ferred embodiment of the invention, and modifications thereto, with the understanding that the present disclo- ' sure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.Figures 1 and 2 show a packless acoustic silen¬ cer 10 which includes a four sided duct member 12. With- in the duct is positioned a pair of opposed facing panels 14 having a generally flattened semi-elliptical shape. The opposing flat portions 14a of each panel are per¬ forated to provide a plurality of holes h which open to chambers (or cavities) 16 formed behind each panel and separated by partition walls 18.Silencer 10 is adapted to be placed in a duct system, e.g. heat, ventilating and air conditioning duct. The gas flow, e.g. air, is in the direction indicated by the arrow although gas flow may also be reversed. Duct member 12 may be made of galvanized sheet metal or other materials .Facing panel 14 is made from galvanized or stainless steel or other metallic or non-metallic, struc¬ turally stable material. Advantageously, the perfora- tions have a hole diameter as small as is economically available from a conventional perforation punching pro¬ cess. A diameter of 0.032 or 0.046 inch is suitable for 26 gauge material, applicable to an air conditioning silencer; and 0.125 is suitable for 11 gauge steel which might be used in a gas turbine silencer. Advsn- tageouflly, the spacing of the perforations h is suπh that an open are* ratio of less than 207-, preferably in thp range of 2 to 107. is achieved along the face panels. The thickness of rhe face, panel may be in the range of 26 gauge to 11 gauge (0.018 to 0.12 inch).Lighter gauges of corrosion resistant material might be used if provision is made for structural support and stiffening. Heavier gauge might be used in some spe¬ cial applications, but probably with a loss of sound dissipation efficiency.The perforated panel or sheet 14 is character¬ ized by its hole diameter d, , hole separation S, and sheet thickness t. The acoustical (dynamic) impedance of the sheet Z , consists of a resistive part RB and a reactive (mass reactive) part Xs * The acoustical im- pedance of the air cavity 16 behind the sheet depends upon the depth d and the spacing between partitions S . The impedance of the cavities 16 is mainly reac¬ tive, representing a stiffness at low frequencies with a corresponding reactance X .The attenuation of the silencer may be express¬ ed in terms of an imoedance Z which is the sum of the sheet impedance Zs„ and the cavity J reactance.The total resistance is equal to the sheet re- sistance 8„ and the total reactance X is the sum of the εheet and cavitv reactance, X ■ Xβ„ + Xc...Attenuation is a complex function of R and X. As a design suide, it has been found that optimization of the attenuation is approximately equivalent to maxi- mization ofthe following quantity:R_Rs + <Xs + XcThus. Rs cannot be too small or too large and ^Xs + Xc^ cannot bβ t0° large.Optimization of the resistive factor for silen¬ cers suited to the applications Dreviously noted is ob¬ tained with an acoustic flow resistance. Rs„■- in the range of 1 to 4 <?r. where θc is the characteristic re- siεtance of gas. e.g. air. -- t1 being density and c being the speed of sound for the particular application. This resistance in prior art silencers has been provid¬ ed by the viscous friction in the pores of resistive sheet materials. In the. present invention, however, an optimum flow resistance is produced bv interaction of mean flow in the duct with the perforated facing panel. The mechanism, through which mean flow υroduces an optimum resistance, is related to an acoustically induced de- flection or switching of some of the mean flow in and out of the perforations. This switchinε requires energy which is taken from the sound field. This effect, first observed by C.E. McAuliffe in 1950. Study of Effect of Grazing Flow on Acoustical Characteristics of an Aper- ture, M.S. Thesis. Department of Naval Architecture,M.I.T.. can be expressed as an equivalent acoustic re¬ sistance of the sheet.In addition, the total attenuation depends on the width π of the Rilencer flow passage and the length .In utilizing a perforated sheet chosen to pro- vide (in conjunction with mean flow) the desired pro¬ perties for dissipation of sound, a serious problem arises which, until the present invention, prevented theuse of perforated sheets to form a packless βilen- cer. The problem, initially referred to as whistle , has to do with the self-noise which was produced by interaction of flow with the sound and with the per¬ forations in the sheet.The self-noise produced by a silencer depends on the flow speed and on the geometrical parameters of the perforated sheet.Theoretical analysis has provided some guide¬ lines for optimization of attenuation. However, there is at present no reliable theoretical analysis from which the level of self-noise can be predicted, and applicants have had to rely on experimental studies to establish self-noise characteristics.A combined theoretical and experimental inves¬ tigation, involving tests of over a hundred configura- tions , has led applicants to a range of design para¬ meters which yield the maximum possible attenuation with self-noise acceptable even in critical HVAC appli¬ cations which do not complicate, or significantly in¬ crease the cost of,the perforated resistive sheet. Experimental investigation confirmed that op¬ timum properties of sound dissipation are obtained with perforated open areas in the range of 2.5 to 107.. A correlation of self-noise level with mean flow velo¬ city and percent open area, and a correlation of peak self-noise frequency with mean flow velocity and the perforation geometry have been found. Discovery of a correlation of self-noise level with perforation geo¬ metry permits the reduction in self-noise of as much as 30 decibels by choices of perforation geometry that still fall within the ranee of economically producibleOMPI and commercially available perforated metal sheets.The appended graphs, Figures 8-11, illustrate some of the significant correlations that appli¬ cants have obtained. Figure 8 shows self-noise for packless silencers with various face sheet perforation diameters but otherwise of identical configuration and construction and at the same mean flow velocity. The perforated face sheet in each was 26 gauge with a 2-1/27. open area. The perforation diameters ,032, ,046, .062, .078, .094. .125 and .188. The air flow speed is 1500 feet per minute (FPM) .Figure 9 shows self-noise under similar condi¬ tions as described above except that the two silencers compared have perforations of the same diameter (.125 inch) but have different perforation geometries in that thickness of the perforated sheets is different (26 gauge and 11 gauge) with flow at 1000 FPM.Figure 10 shows calculated packless silencer attentuation for an effective face sheet flow resis- tance of 2 ^c versus actual performance of a silencer constructed according to this invention.Figure 11 shows attenuation of three silencers constructed according to this invention with 1. 2.5 and 7.27. perforated face open areas. This graph illustrates loss of performance with open area less than 27..The silencer 10 as previously discussed re¬ places a length of duct work in a gas passage. Although the face panels 14 are illustrated as being on opposite sides of the flow chamber, the entire flow passage may be faced with perforated face panels of the type des¬ cribed, e.g. rectangular or cylindrical duct with a packless duct liner.In some applications, it may be desirable, de¬ pending upon allowable flow restriction and acoustical requirements, to arrange several silencers in series. Some of these arrangements are Illustrated in Figures 3-7, wherein corresponding numerical designations indicate corresponding elements.Figure 3 illustrates a tandem arrangement of three silencers 10 which provide a convenient means of extending the effective lenizth of the silencer through the use of standard silencer modules.Figure 4 illustrates a combined silencer which includes a first silencer 10 and a second silencer 20 in tandem. Silencer 20 is similar in structure to silen¬ cer 10 except that its flow passage includes a splitter element 25. Splitter 25 is generally of a flattened elliptical shape and provides perforated facing panels 25a adjacent the gas flow passages. The center of splitter 25 includes cavity partitions 25b. The proce¬ dure for selecting the hole size and open area of the face sheets is as previously described. Cavity depth and flow passage width are chosen to optimize attenua¬ tion at a higher frequency for silencer 20 than for silencer 10. This combination provides better dynamic insertion loss (DIL) in some octave bands than does a combination of two silencers of configuration 10 so that design flexibility may be increased if acoustic noise tn these octave bands is critical in the appli- cation.Figure 5 illustrates a silencer combination of silencers 10 and 20 joined by a transition member 30. Member 30 provides a tapered transition from silencer 10 to silencer 20 and includes perforated face panels 34 and a centrally disposed generally triangular shaped splitter 35 having perforated facing panels 35a adjacent the flow paths and a central longitudinal partition wall 35b. The transition member 30 is useful in improving DIL in the higher frequencies and in reducing flow restriction.OMP< Figure 6 illustrates a pair of silencers 10 joined by a hi?h frequency transition member 40. This arrangement, similar to that shown in Figurt 5, supple¬ ments DIL of similar silencers in tandem, transition member 40 includes lateral perforated facing panels 44 which define a cavity 46 with longitudinally disposed partitions 48. A central splitter 45 of flattened el¬ liptical βhape includes perforated facing panels 45A and a longitudinal partition wall 45b. Figure 7 illustrates A triple tuned silencer arrangement wherein the flow passage width is progres¬ sively reduced by a factor of 1/2 through three silen¬ cers, as indicated in the figure. This arrangement has application in situations where e^en broader range DIL is desired. The arrangement includes a silencer10' having a flow passage width of d joined to a single splitter silencer 20' having two flow passages each d/2 in width.Finally, silencer 50 includes three splitters 55 which further divide the flow oassages to a width of d/4. Each splitter 50 includes a pair of Derforated facing panels 55a and central longitudinally disposed partition wall 55b. The duct wall also Includes per¬ forated facing panels 54. From the above description, it will be readily apparent to those skilled in the art that other modifi¬ cations may be made to the present invention without departing from the scope and spirit thereof as pointed out in the appended claims. | WE CLAIM:1. A packless acoustic silencer comprising facing panel mean* separating fluid flow patha from adjacent acoustical cavities; βflid facing panels being perforated sheets having an open area in the range of 2-10 percent, said open area causing a switching action of the mean fluid flow in and out of the perforations, whereby the acoustic energy of the air flow is reduced.2. The silencer of Claim 1, wherein said per- forationβ have an effective diameter in the range of from about .032 inch to 0.125 inch respectively for sheet thicknesses from 26 gauge to 11 gauge,3- The silencer of Claim 2, wherein said per¬ forations are circular in shape. 4. The silencer of ClAim 2, wherein said facing panel is between 1/64 to about 1/8 inch in thickness.5. The silencer of Claim 1, further including at least one splitter element having perforated facing panels with a percent open area in the range of 2-10 per cent.6. The silencer of Claim 1, further including a second silencer joined in tandem therewith.7. The silencer of Claim 6, further comprising a transition silencer located between said silencer and said second silencer.'8 The silencer of Claim 7, wherein said tran¬ sition silencer is tuned for optimum dynamic insertion loss spectra appropriate to the intended application. 9. A packless acoustic silencer comprising facing panel means separating fluid flow paths from adjacent acoustical cavities, said facing panels being perforated sheets having an open area in the range of 20 per cent, said open area causing a switching action of themean fluid flow in andout of the perforations, where- by the acoustic energy of the air flow is reduced.O PI. A< •_- WIPO 10. The silencer of Claim 9, wherein said per cent open area is in the range of 2 to 10 ptr cent. | INDUSTRIAL ACOUSTICS CO; IND ACOUSTICS CO INC | HIRSCHORN M; INGARD U; MORGAN J |
WO-1979000297-A1 | 1,979,000,297 | WO | A1 | EN | 19,790,531 | 1,979 | 20,090,507 | new | B21D51 | C10M3, B65D25 | B21D22, B21D51, C10M105 | B21D 22/20B, C10M 105/32, M10M 207/281, M10M 207/282, M10M 207/283, M10M 207/286, M10M 290/04, M10N 240/402, M10N 240/403, M10N 240/404, M10N 240/405, M10N 240/406, M10N 240/407, M10N 240/408, M10N 240/409 | METHOD OF MAKING METAL CONTAINERS | A precoated stock material for use in forming a drawn and ironed container and a method of forming such container is disclosed herein. In the past, water soluble lubricants applied to the stock material during drawing and ironing had to be removed to produce an acceptable surface for subsequent coatings or decorations. This often involved use of harsh chemicals which, in some cases, involved potential health hazards. Recent efforts aimed at use of partially cured coatings containing lubricants applied prior to drawing and ironing have been unsuccessful in the sense that production rate is unacceptable and the coating is often removed during ironing. In this invention, the stock material initially has a layer of lubricant applied to at least one surface of the metal base with the lubricant consisting essentially of a Fatty acid ester of a mono or polyhydric alcohol and having a distribution of less than 0.5 mg./cm.<s2>s (3 mg./in.<s2>s). The method contemplates applying the layer of lubricant to a metal stock, such as aluminum, black plate or tinplate, cutting a disc from the metal stock, and transforming the disc into a drawn and ironed container without additional lubricant being applied to the tooling. In one version of the invention, a black plate stock material has a curable polymeric coating applied to one surface which is then partially cured and a layer of lubricant is applied to the other surface. | METHOD OF FORMING SEAMLESS CONTAINERSBackground of the InventionThe present invention relates generally to containers and more particularly to an improved stock material for making containers and a method for forming seamless drawn and ironed containers from the improved stock material.The use of a two-piece container for packaging beer and/or carbonated beverages has become very popular in recent years. The two-piece container consists of a container sidewall or body that has a unitary end wall at one end thereof. The second piece for the con¬ tainer consists of an end which is seamed to the open end of the container.In the formation of drawn and ironed containers, a finished container is produced by initially cutting a disc from a sheet or coil of stock material and substan¬ tially simultaneously transforming the disc into a shallow cup in a conventional cupping machine that forms part of a can manufacturing line. The shallow cup is then converted into a drawn and ironed container in a body maker wherein the shallow cup is reformed into a cup of different dimensions and then passed through a plurality of ironing rings that cooperate with a punch to decrease the wall thickness of the reformed cup and produce a seamless container. Alternatively, the cup may initially have a diameter substantially equal to the final diameter so that the reforming or redrawing in the body maker is not necessary.In most commercial machinery utilized for forming the cups and then converting the cups to drawn and ironed containers, a lubricant-coolant is utilized in the cupper for providing the necessary lubricity between the surface of the sotck material and the tooling. The body making machinery also incorporates mechanism for flowing a lubricant-coolant to the surface of the container and to the ironing dies utilized in cooperation with the punch. Conventionally, the lubrican coolant consists of a mixture of water and an emulsified oil or emulsified synthetic lubricant, such as a com¬ mercially available Texaco 591 product. One of the difficulties with utilizing the water soluble emulsified oils in the cupping as well as the drawing and ironing tooling is subsequent cleaning of the finished con- tainers to remove the emulsified oils from the surfaces thereof. In order to produce an acceptable surface that can subsequently be coated and/or decorated, it is necessary to utilize harsh chemicals and washing tempera¬ tures as high as 72° C to remove the undesired emulsified oils. Furthermore, it has been determined that some emulsified oils may become toxic which presents a po¬ tential health hazard.Presently, most drawn and ironed containers are formed from aluminum because of the relative ease in fabric'ability of the container. Because of the cost of aluminum, manufacturers are constantly striving to find an acceptable substitute for aluminum which can be manufactured at a competitive cost.One acceptable alternative for the drawn and ironed aluminum container is commonly referred to as tinplate. This material includes a base plate of low carbon steel, such as black plate which has both' sur¬ faces covered with a thin layer of tin. The tin coating acts as a low friction, ductile material during the ironing process and also resists corrosion. While tinplate has been found to be an acceptable alternate for aluminum, the availability of this material is limited and the cost is high.OMP WIP Bethlehem Steel Corporation also has continued its development efforts for producing a beer and carbonated beverage container from black plate using conventional machinery by applying organic coating to the black plate which can then be drawn and ironed at a price which is competitive to the present day tinplate or aluminum container. To this end, a proposed process is disclosed in United States Patent No. 4,032,678. This process contemplates the formation of special organic coating systems that enable container manufacturers to produce drawn and ironed beer and soft- drink cans from black plate. The foregoing patent describes two coating concepts that have been developed for black plate, one of which consists of admixing a thermosetting coating and a lubricant and applying this mixture to both sides of the black plate blank and partially curing the mixture before the blank is con¬ verted into a finished container. The other concept contemplates supplying the coating-lubricant mixture to only the one side of the blank (the side forming the outside of the can) , and applying a coating lubricant alone to the other side of the blank (the side that forms the inside of the can) ,However, while such process is acceptable in laboratory trials at slow speeds, actual tests have shown that the partially-cured coating having the lubricant mixed therein, while allowing drawing and ironing of the container, is not acceptable for making cans at commercial production rates and most of the coating is removed during the ironing process when containers are manufactured at rates of more than 150 containers per minute. It was also determined that the coating was removed in the form of large flakes or long narrow strips which would be introduced into the coolant and would rapidly clog up the filtering system for the coolant. These flakes or strips would also be carried by the container to downstream areas of the container processing line which disrupted the proper processing of the containers.Summary of the Invention It has been determined that all lubricants in the cooling fluid can be eliminated by applying a thin layer of an organic ester to the stock material before the cupping operation is initiated.According to the present invention, a metal base of stock material that is to be used for forming a drawn and ironed seamless container first has a thin layer of lubricant applied to at least one surface of the metal stock or blank and a disc is cut from the metal blank and formed into a shallow cup without the use of any additional lubricant or coolant. The shallow cup is then further drawn and ironed to produce a seamless container which again is done without the use of any additional lubricant in the liquid coolant, such as water, in the drawing and ironing machine. More specifically, the thin layer of lubri¬ cant consists essentially of a fatty acid ester of a mono or polyhydric alcohol and the layer has a distribu- tion or thickness preferably less than 0.5 mg./cm.2 (3 mg./in. ) . It has been determined that applying a single2 layer of less than 0.5 mg./cm. of an organic ester to one surface only of black plate, tinplate or aluminum by a commercial lubricator eliminates the need for any subsequent lubrication in the cupping machine as well as the body maker.According to another aspect of the invention, a black plate container can be formed by initially applying a layer of curable polymeric coating on a surface of the black plate which will become the external surface of a container, partially curing the coating within certain critical limits, and applying the lubri- cant to the other surface of the black plate.The curable polymeric coating is applied in2 an amount of about 0.2 (1) to about 0.7 mg./cm. (4 mg./2 in. ) of blank area. It has also been determined that the optimum thickness of the coating should be about 0.3 (2) to about 0.5 mg./cm. 2 (3 mg./in.2) on the surface of the metal plate. The coating can be cured to the desired degree by continuously feeding the coated stock through an oven to achieve a temperature for the metal portion of the strip of more than about 204 degrees C • but less than the degradation temperature for the applied coating and maintaining the strip within the oven for a time period of approximately one minute. The partial curing may also be accomplished by baking the coated blank at a temperature of approximately 177 degrees C for a period of approximately- 10 minutes. The present process is particularly well suited for the manufacture of containers from pure ferrous metal such as black plate of tin-free steel stock.Description of the Invention In its broadest aspect, the present inven¬ tion contemplates precoating a metal sheet or coil with, a thin layer of lubricant to one surface only of the metal sheet or coil, cutting a disc from the metal sheet or coil with the lubricant applied to one sur- face, forming a shallow cup from the disc subsequentlyΪΛJREAIΓOMPI < WIPO Λ> redrawing and ironing the shallow cup into a full sized container.Stated another way, a stock material, such as an aluminum, black plate, or tinplate metal sheet or 5 coil, has a layer.of lubricant consisting essentially of a fatty acid ester of a mono or polyhydric alcohol applied to one surface of the stock material to a thick- ness of less than 0.5 mg./cm. 2 (3 mg./in, _>) and pref- erably about 0.2 mg./cm. (1 mg./in. ) and the pre-10 treated stock material is then utilized in forming a seamless drawn and ironed container that has a bottom wall and an integral sidewall in conventional cupping and body making machinery that is presently utilized for making such containers. By applying the lubricant15 to the stock material before a disc is cut therefrom, all additional lubricants in the drawing and ironing process can be eliminated and it is only necessary to provide the body maker with a water coolant that has a small amount of rust inhibitor therein to maintain20 the tooling below a predetermined temperature.One lubricant that is suitable for carrying out the present invention is a fatty acid ester of a mono or polyhydric alcohol. A commercially available lubricant of this type is produced by Mobil Chemical '25 Company under the designation S-6661-003. More specifically, this ester is made from a monomeric polyhydric alcohol having three to six hydroxyls and a 14 to 20 carbon fatty acid.The Mobil lubricant was successfully applied30 to one surface of black plate, tinplate and aluminum plate by a lubricator to produce a thin layer of lubricant having a thickness or distribution of less than 0.5 mg./cm. ~ (3 mg./in.2). on the surface of the stock material that ultimately becomes the insideOMPI. W1P0 of the container. If necessary, to produce the desired thickness of the layer, it may be necessary to either thin, the fatty acid ester with a solvent before it is applied to the surface of the stock material, or simply by heating the material before it is applied by the lubricator. A further alternative form of heating would be to heat the rollers that form part of the lubricator.When black plate is used as the base mate- rial, it is preferably pretreated by applying an organic or polymeric coating to at least one surface thereof and partially curing the coating.Curable organic or polymeric coatings suitable for the purposes of the present invention are exemplified by the curable epoxy resins, e.g., the glycidyl poly- ethers of polyhydric phenols, the epoxy novolac resins, the glycidyl ethers of aliphatic polyols, the cycloaliphatic epoxy resins, and the like, the curable vinyl resins, the curable epoxy-urea-formaldehyde resins, and similar curable polymers.Preferred for the present purposes are the curable epoxy resins having a chain of alternating glycidyl and divalent phenolic units united through an ether oxygen and having glycidyl units in the terminal positions of the chain. The ether oxygen (as distinguished from the oxirane or hydroxy oxygen) is linked to the primary carbon atoms of the glycidyl units. These particular epoxy resins are glycidyl polyethers of polyhydric phenols. Exemplary are the reaction products of epichlorohydrin with a dihydric phenol represented by the general formula as follows: wherein n can have a value of 1 to about'20, wherein R can bewherein R1 can be 10Suitable dihydric phenols for reaction with epichlorohydrin to produce the aforementioned resins are20 -resorcinol, catechol, the polynuclear phenols such as1,1-bis (4-hydroxyphenyl)ethane,1,1-bis (4-hydroxyphenyl)propane,2,2-bis (4-hydroxyphenyl)propane,25 2,2-bis (4-hydroxyphenyl)butane,1,1-bis (4-hydroxyphenyl)butane,1,1-bis (4-hydroxyphenyl)-2-methylpropane,3,3-bis (4-hydroxyphenyl)pentane, and the like.Preparation of the foregoing products is well30 known in the art and generally involves heating the dihydric phenol with epichlorohydrin at a temperature of about 49 degrees C to about 199 degrees C in a basic reaction medium. The desired molecular weight-BUROMP W1P of the reaction product is obtained by varying the relative amounts of the phenol and epichlorohydrin.In addition, a portion of the foregoing reaction product can be combined with a reactive modifier to increase toughness, flexibility, elonσa- tion and/or adhesive peel strength. A particularly preferred modifier is a xylene-formaldehyde resin condensed with the aforementioned reaction product. A particular preferred curable polymeric composition for the practice of the present invention comprises a 4,4'- isopropylidene-diphenol-epichloro- hydrin resin having a portion of the resin condensed with a xylene-formaldehyde resin. A curable polymeric composition of this type is available commercially from Mobil Chemical Company under the designation S-9019-001.The degree of cure of the applied curable coating for drawing and ironing is very important. The applied coating should be about 50 to about 75% cured before drawing and ironing, and preferably about 60 to about 70% cured. Stated in another way, the coating should be cured to a degree so that about 25% to about 50% of the coating constituents are extractable, preferably about 30 to about 40% of the constituents are extractable by methylene chlorideIn the extraction test, the coating was extracted in the following manner:1) Each coated metal disc was weighed and the total weight was recorded. 2) Each coated disc was then soaked in methylene chloride for thirty minutes.3) The discs were dried in an oven at 107 degrees C for thirty minutes .4) Each disc was again weighed.'BUREATJ'OMPI . fa W1PO . 5) The total weight loss for each disc was determined, ie, step 1-4,6) The percent extraction was then determine using the following formula:Percent Extracted = weight loss in (5) x 100 total weight of coatingActual comparisons were made between black plate that was coated on one side only with a partially cured organic coating, with and without having an internal lubricant mixed with the organic coating. Contrary to the teachings of the above Bethlehem patent, actual tests snowed that containers formed from black plate coated with the organic coating, but without having an internal lubricant mixed with the coating, retained substantially more coating on the finished container than when the internal lubricant was present in the organic coating. Furthermore, production formability was enhanced by applying a thin layer of lubricant to the other surface of the blank.Example I Laboratory tests were conducted by applying a layer of approximately 0.2 mg./cm.2 (1.25 mg./in.2) of the above Mobil lubricant on one surface of a sheet of tinplate stock material. The sheet of stock mate¬ rial was then cut and formed into a shallow cup in a conventional manner without the addition of any further lubricant or without any water. The cups with the layer of lubricant on the inner surface, were then reformed into finished containers in a conventiona body maker where only water alone or water with 0.05% rust inhibitor was circulated through the tooling used in producing the finished container. Some containers were made using a water-emulsion oil mixture for the coolant.'B JOM Container's made from the organic ester pre- applied sheets or coils consistently showed better cleanability when water alone was used as the coolant.In all instances the containers made without the emulsion oil lubricant had a smooth and uniform surface appearance.Example IIAluminum stock material in the form of plates was coated on one side with an organic ester, such as the Mobil lubricant, to produce a layer on one surface2 having a distribution of approximately 0.2 mg./cm. (1.25 mg./in. ). These plates were then converted into cups and subsequently cans utilizing a commercially available cupper and body maker. In converting the plates into cups, the plates were positioned so that the lubricated surface became the internal surface of the cup and no additional lubricant or water was needed to produce satisfactory cups from the plates. The cups were then converted to finished containers in the body maker utilizing -only tap water. Several thousand of such cups and containers were produced and inspection of the finished containers showed that the containers had a shiny outside surface and a scratch-free inside sur¬ face. The containers were then cleaned using several standard cleaners with less than the present standard recommended concentration to remove all of the lubri¬ cants from the container surfaces.Example III A coil of black plate stock material was cut into sheets and each of the sheets was coated on one surface with Mobil S-9019-001 organic coating to2 produce a layer of approximately 0.5 mg./cm. (3 mg./ in.2) and the plate was baked at 177 degrees C for five minutes to partially cure the coating. A Mobil S-6661-003 lubricant was then roll-coated with a thin layer (0.4 mg./cm. ) on the other surface of the sheets to produce a thin layer of lubricant. The sheets were then stacked and delivered to a cupping machine and during this process some of the lubricant was transferred to the coated, partially-cured surface of the sheets.Discs were then cut from the sheets and con¬ verted into shallow cups using commercial cupping equipment without the use of any water or additional lubricant. The shallow cups had the layer of lubricant on the inner surface and the organic coating on the outer surface. The cups were then converted into drawn and ironed containers in a commercial body maker. Some containers were formed from cups using only water aa the cooling agent while other containers were formed using a lubricant-coolant. This lubricant-coolant ' was a water and emulsified oil mixture which included about 15% of a Texaco 591 emulsified oil. In all instances, the containers formed with water alone had as good or better surface appearance then those formed using the lubricant-coolant mixture.Example IV A coil of dry black plate was coated with a Mobil S-9019-001 organic coating to produce a layer of approximately 0.55 mg./cm. ~ (3.25 mg./in.2).The coated coil was passed through an oven that had three temperature zones so that the metal surface temperature reached approximately 216 degrees C to partially cure the coating. The coil with partially- cured coating was then subjectee to an extraction test and it was determined that 34% of the coating was extracted, ie, the coating was about 66% cured. The other surface was roll-coated with Mobi_lS-6661-003 lubricant to provide a coating thickness car less than 0.3 mg./cm. 2 (2 mg./in,?), The material was then cupped without the use of any water or additional lubricant. The cups were then drawn and ironed using water only as a coolant in the body make r. The cups were converted into containers without difficulty, and the containers were run through the remainder of a can making line without difficulty. The cure of the partially-cured organic coating was completed after the drawing and ironing step, as the containers were passed through the remainder of the container processing line.The above tests establish that drawn and ironed containers can be formed from coated black plate, aluminum or tinplate by precoating the stock material with a thin layer of an organic ester lubricant and the drawn and ironed containers can be formed without the use of water or emulsifiable oils in the cupper and using only water as a coolant in the body maker or drawing and ironing machine.It is believed that elimination of the water emulsion oils from the process and substitution of the organic ester results in a cost savings of approximately 50% in the lubricant alone and also provides additional savings in the use of milder cleaners and lower cleaning temperatures.It has also been established that the organic ester lubricant provides better lubrication for the tooling than the water-lubricant mixture. This is believed to result from the fact that the lubricant is initially located directly between the tooling and the container surface interface and also from the fact that the organic ester lubricants withstand the high .temperatures encountered during ironin of the metal body without deterioration. Also, applying the layer of lubricant to the surface which becomes the inner surface of the container is believed to aid in stripping the ironed container from the punch.Of course, if desired, both surfaces of the stock material could be coated with a lubricant and/or the distribution or thickness of the layer or layers could be increased. However, tests have shown that increasing the thickness of the coating on one surface only will not increase the efficiency of the opera¬ tion but will increase the cost without any addi¬ tional benefits. Respecting the two-sided coating with lubricant, it was determined that the additional coating on the second side increased the costs without deriving any benefits from the increased cost. In other words, tests showed that one side coated mate¬ rial would have enough lubricant transferred to the other side- during the processing of the stock material and in the cupper and body maker to eliminate the need for applying lubricant to the second side.While the manner of applying the lubricant to the stock material is not critical in carrying out the present invention, the lubricant is pref¬ erably applied as the stock material is fed to the cupping machine. When the lubricant is applied to a stock material which also has an organic coating applied to one side, such as Example III, the coating and lubricant could simultaneously be applied to opposite sides of the stock material with a lubricator and the material could then be passed through an oven to partially cure the organic coating. It has been determined that the heating of the lubricant in theJUROM oven has no deleterious affect on the lubricant. Of course, the lubricant could also be applied in other ways. For example,' it would be possible to apply the lubricant to the stock material in the cupping machine as the discs are being severed from the stock: material and the appended claims are intended to cover such alternate method of application. | WHAT IS CLAIMED IS;1. A method of forming a seamless container having a bottom wall and an integral sidewall from a sheet of metal stock material by cutting a disc from said stock material drawing said disc into a cup and substantially reducing the sidewall of said cup to produce a drawn and ironed container, characterized by applying a thin layer of lubricant to said stock material before said disc is cut from said stock material, and forming said seamless drawn and ironed container without applying any additional lubricant to said stock material.2. A method as defined in claim 1, character ized by said layer of lubricant being applied in an amount not exceeding 0,5 mg./cm.2.3. A method as defined in claim 2, character ized by said layer of lubricant having a thickness of approximately 0.2 mg./cm. -4. A method as defined in any one of claims 1 to 3 characterized by said lubricant consisting essentially of a fatty acid ester of a polyhydric or monohydric alcohol.5. A method as defined in claim 4 , characte ized in that said metal is aluminum.6. A method as defined in claim 4, character ized in that said metal stock material is tinplate.7. A method as defined in claim 4, further characterized by applying a layer of polymeric curableOM coating free of any lubricant to the other surface of said metal stock material and heating said material to partially cure said coating before cutting said disc and subsequently heating said seamless drawn and ironed container to fully cure said coating.8. A method as defined in claim 7, in which said metal stock material is black plate and said coating is present in an amount of about 0.2 to 0.7 mg./cm.2.9. A container produced by the method defined in claims 1 through 8.10. A metal stock material having a lubricant as defined in claims 1 through 4. BU EAUOMPI AMENDED CLAIMS (received by the International Bureau on 9 May 1979 (09.05.79))1. A method of forming a seamless container having a bottom wall and an integral sidewall from a sheet of metal stock material by cutting a disc from said stock material, drawing said disc into a cup and substantially reducing the sidewall of said cup in a multistage ironing process to produce a drawn and ironed container, characterized by applying a thin layer of2 lubricant of at least 0.2 mg./cm. to at least one surface of said stock material before said disc is cut from said stock material, and forming said seamless drawn and ironed container, and maintaining at least some of said lubricant on said surface throughout said multi¬ stage ironing process. 2. A method as defined in claim 1, character¬ ized by said layer of lubricant being applied in an2 amount not exceeding 0.5 mg./cm. .3. A method as defined in claim 2 character- ized by said layer of lubricant having a thickness of2 approximately 0.2 mg./cm. .4. A method as defined in any one of claims 1 to 3 characterized by said lubricant consisting essentially of a fatty acid ester of a polyhydric or monohydric alcohol. 5. A method as defined in claim 4, character¬ ized in that' said metal is aluminum.6. A method as defined in claim 4, character¬ ized in that said metal stock material is tinplate.7. A method as defined in claim 4, further characterized by applying a layer of polymeric curable coating free of any lubricant to the other surface of said metal stock material and heating said material to partially cure said coating before cutting said disc and subsequently heating said seamless drawn and ironed container to fully cure said coating. 8. A method as defined in claim 7, in which said metal stock material is black plate and said coating is present in an amount of about 0.2 to 0.72 m ./c . .9. A container produced by the method defined in claims 1 through 8.-BUREAUOMPI STATEMENTUNDERARTICLE19There is submitted herewith an amended set of claims in the above application comprising new pages 16 and 17. Please enter these amended claims into the above application in accordance with the rules pertaining to Patent Cooperation Treaty applications.-BUROM | NAT CAN CORP; NATIONAL CAN CORP | HESSEL W; MISRA S; OPENCHOWSKI R; ZENGER R |
WO-1979000306-A1 | 1,979,000,306 | WO | A1 | XX | 19,790,531 | 1,979 | 20,090,507 | new | G01N33 | G01N31 | G01N27, G01N31, G01N33 | G01N 33/92 | DETERMINATION OF LDL CHOLESTEROL IN BODY FLUIDS | A method for determining the level of LDL cholesterol in body fluids is disclosed wherein a plant lectin which is a specific agglutinating agent for LDL is employed to selectively agglutinate LDL thereby separating LDL cholesterol from other soluble cholesterol fractions. | DescriptionDetermination of LDL Cholesterol in Body FluidsTechnical Field This invention is in the field of clinical assay techniques.Background ArtLipoproteins are complex particles consisting of protein and lipid which are found in the circulatory - system- One of their functions is to carry water insol¬ uble substances, such as cholesterol and cholesterol esters, for eventual cellular utilization. While all cells require cholesterol for growth, excess accumula¬ tion of cholesterol by cells is known to lead to certain diseases including atherosclerosis.It is known that the amount of total serum cholesterol can be correlated with the incidence of atherosclerosis. However, there are a variety of classes of lipoproteins in serum which can be classi- fied by their density. These classes include very low density lipoproteins (VLDL) , low density lipoproteins (LDL) , and high density lipoproteins (HDL) . All of these li oprotein classes contain varying amounts of cholesterol, and a total serum cholesterol determina- tion is a complex average of the amount that each lipo¬ protein class contributes to the total lipoprotein population of the serum. It has long been suspected that specific lipo¬ protein classes were more closely associated with the progression of heart disease, including atherosclerosis. In fact, more recent studies have implicated LDL as the class of lipoproteins responsible for the accumulation of cholesterol in cells whereas HDL has been shown to be important in the removal of excess cholesterol from cells. Additionally, the correlation of atherosclerosis and the levels of LDL cholesterol is much higher than a similar correlation between atherosclerosis and total serum- cholesterol levels. Conversely, there seems to be a negative correlation of atherosclerosis and HDL cholesterol levels. See, Gofman, J. W. , Jones, H. B. , Lindgren, F. T., Lyon, T. P., Elliot, H. A., and Strisower, 3., Blood Lipids and Human Atherosclerosis, Circulation, 2_:161-178 (1950) ; Barr, D. P., Russ, Ξ. M., and Ξder, H. A., Protein-Lipid Relationships in Human Plasma, II, In Atherosclerosis and Related Conditions, Am.. J. Med. 11:480-493 (1951) ; Nikkila, E., Studies on Lipid Protein Relationships in Normal and Patholog¬ ical Sera and Effect of Heparin on Serum Lipoproteins, Scand. J. Clin. Lab. Invest. Supplement., 5_;1-101 (1952); Jencks, W. P., Hyatt, M. R. , Jetton, M. R. , Hattingly, T. W., and Durrum, E. L-, A Study of Serum Lipoproteins in Normal and Atherosclerosis Patients by Paper Electro- phoretic Techniques, J. Clin. Invest., 3.'980~990 (1956) , and Miller, G. J. and Miller, N. E., Plasma-High-Density Lipoprotein Concentration and Development of Ischemic Heart Disease (technical note) , Lancet, 1_, (7897) 16-19 (1975) .Despite the desirability of determining LDL cholesterol levels from other lipoprotein cholesterol levels, a technique suitable for use in clinical labor¬ atories has not heretofore existed. The method most often used relies upon the interaction of heparin in the presence of calcium to precipitate both LDL and VLDL. See Burstein, M. and Scholanick, H. R. , Adv. Lipid Res . , 11, 67 (1973) . To separate the LDL and VLDL fractions, ultracentrifugation techniques, which are time consuming and expensive, have to be employed.Thus, a long existing need has existed for a simple, inexpensive, quantitative methodology to determine LDL cholesterol levels in blood plasma or other body fluids so that patients can be given a better assessment of their potential cardiovascular risk than that provided by presently used total serum cholesterol level assays.Disclosure of the Invention This invention relates to the discovery that certain plant lectins act as specific agglutinating agents for LDL contained within body fluids such as blood plasma, blood serum, lymphatic fluid, etc. Be¬ cause of this , LDL can be isolated from other lipo- proteins, such as HDL, and VLDL, by agglutina ing the LDL with a lectin. Thereafter, the cholesterol content of isolated LDL can be determined.Agglutination is a clumping together of LDL particles which causes then to precipitate. While not wishing to be bound by this theory, it is believed that suitable lectins react with sugar residues -of the glycolipids contained in the outer surface of LDL but not the other glycoproteins . This apparently results in a type of crosslinking which causes the agglutina- tion and precipitation.Best Mode of Carrying Out the InventionWhile most of the. work described herein has been done with lectin isolated from castor beans (Ricinus Communis) , it is believed that many other plant lectins*- could also be used. Since lectins are ubiquitous plant proteins, there is a wide variety from which to choose. Those lectins which are specific for galactose residues are preferred. In addition to castor bean lectin, peanut lectin is known to be specific for galactose residues. Those skilled in the art will know, or be able to ascertain using no more than routine experi¬ mentation, other lectins which selectively agglutinate LDL, especially those specific for galactose residues. On the other hand, all lectins are not satisfactory, For example, wheat germ lectin has been found ineffec¬ tive in causing selective agglutination of LDL. Other lectins, such as concanavalin A, when linked to a Sepharose 4B column, do retard the migration of LDL but also retard migration of VLDL. See McConathy, W. J. and Alaupovic, P., FEBS Letters, 41, 174(1974) . This is believed to occur because concanavalin A inter¬ acts with mannose residues of the glycoproteins .It has been found that LDL can be selectively pre- cipitated from blood serum at 25°C by castor bean lec¬ tin. At lower temperatures, such as 4°C, some VLDL is also precipitated. Thus, the agglutination reaction should be carried out at a temperature sufficient to provide selective agglutination and precipitation of LDL.The agglutination reaction can be carried out by adding a standard solution of lectin to blood serum at a sufficient temperature. The amount' of time required for the reaction depends upon the concentration of the lectin, amount of LDL present, and other such factors. In practice, the time course of agglutination of LDL by a particular .lectin at a particular temperature can be plotted at varying concentrations of the lectin to provide an indication -of the time required for the re- action to co to comoletion. Measuring the amount of- £ agglutination can be easily done by optical methods, such as by measuring the absorbance of light at 450 nanometers .After agglutination has occurred, the resulting agglutinated precipitate can be separated from the blood plasma by centrifugation at low speeds for short periods of time, such as 2 minutes. The precipitates can be resolubilized, if .desired, by relieving the agglutination. This may be done, for example, by adding a. sugar such as galactose or lactose, that competes with the sugar residues of LDL for the lec¬ tin. The resolubilized cholesterol content of the LDL can then be easily determined by known techniques, including optical techniques. One skilled in the art will recognize that the LDL cholesterol content of the body fluid may be determined directly by analyzing the precipitate formed upon the agglutination of LDL with lectin or indirectly by analyzing the supernatant for HDL chol- esterol following centrifugation. In the indirect method of determining LDL cholesterol, the cholesterol remaining in the supernatant following agglutination (HDL + VLDL) is substracted from the total cholesterol (HDL + LDL .+ .VLDL) present in the body fluid. If nec- essary or desirable, corrections can be made for chol¬ esterol bound to other species, suchas that bound to chylomicrons.A particularly convenient procedure for carrying out the method described herein is by means of a kit intended for the determination of LDL cholesterol in a body fluid, such as plasma or serum. Such a kit would include a reagent containing a plant lectin which was a specific agglutinating agent for LDL. The lectin reagent might also contain a stabilizer- and/or preservative for lectin, such as glycerol or proteins such as bovine serum albumin. In a preferred embodiment,, this plant lectin reagent would be lyo- philized and a reconstituting reagent containing an aqueous base or a water-miscible solvent would also be included in the kit. The reagents may optionally also contain buffers for maintaining the reconsti¬ tuted reagent system at a controlled pH and preserv¬ atives and/or stabilizers intended to prevent deteri- oration of the material prior to use. Although, buffers are not considered a critical component of the kit reagents, most preferably a pH of about 5.4 to 8.7 would be used in carrying out the present method. Although the reconstituting reagent preferably would contain water as a solvent, a water-miscible solvent may partly or wholly be used to replace the water. Water-miscible solvents are well known to those skilled in the art and include, but are not limited to, glycerine, alcohols, glycols, or glycol ethers. In addition to the reagent containing lectin, the kit might optionally contain an additional reagent for use in the measurement of cholesterol. Such re¬ agents are well known to those skilled, in the art. Such cholesterol determining reagents may contain sulfuric acid in combination with other chemicals such as ferric chloride or ferric perchlorate. Alternately, completely enzymatic reagents for the determination of cholesterol are available. A cholesterol determining reagent based on either the chemical or enzymatic pro- cedure would be satisfactory for use in the present kit. Where it is desirable to measure the LDL choles¬ terol directly, the kit may also contain a resolubiliz- ing reagent comprising lactose in an aqueous solvent. This invention can be further illustrated by the following specific example.EXAMPLE 1 Ricinus Communis beans were obtained from Stokes Seeds, Buffalo, New York. The Ricinus Communis lectin (RCA) was isolated from the beans according to the method of Nicolson and Blaustein as modified by Podder et al. See, G. L. Nicolson and J. Blaustein. Biochem. Acta, 266, 543 (1972) ; and S. K. Podder, A. Surolia, and B. K. Bockhawat. Eur . J. Biochem. , 44 , 151 (1974) .Plasma lipoproteins were obtained by preparative ultracentrifugation from plasma of normal male blood donors. See, R. T. Hatch and R. S. Lees, Adv. Lipid Res . , 6_, 2 (1968) . LDL was collected between 1.025 and 1.050 g/ml and washed at 1.050 g/ml; HDL was col¬ lected between densities of 1.063 and 1.21 g/ml; and VLDL was collected between densities of 1.006 and 1.019. The purity of the different lipoprotein frac- tions was checked by agarose gel electrophoresis.Protein content was estimated by the method of Lowry et al . using crystalline bovine serum albumin (Sigma) as standard. See, 0. H. Lowry, N. J. Rosen- brough, A. L. Farr, and R. J. Fandall, J. Biol. Chem. , 193, 265 (1951) . Total cholesterol was estimated using ferric acetate-uranium acetate and sulphuric acid-ferrous sulphate reagents. See, A. C. Parekh and D. H. Jung, Anal. Chem, 42, 1423 (1970).The time course for the development of the agglu- tination of isolated LDL was followed by the increase in the turbidity of a solution using 450 nanometer light. At 25°C, the agglutination reaction reached eσuilibrium within 30 minutes. The agglutinated LDL' * was then removed by low speed centrifugation. The equilibrium levels of turbidity could be related to the actual amount of LDL in the agσlutinated complex. A plot illustrating the relation between turbidity at 450 nm and the amount of LDL cholesterol that was not pelleted by low speed centrifugation was made. This cholesterol represented the percentage of LDL not agglutinated. At saturating levels of RCA, greate: than 95% of the LDL cholesterol was agglutinated and removed by low speed centrifugation. When other serum lipoproteins (HDL and VLDL) were treated with the lec¬ tin, no agglutination occurred at 25°C; however, with VLDL some agglutination occurred at 4°C.The agglutination of LDL was relieved by adding a solution of 4 mM lactose. This reversed the agglu¬ tination and the LDL became soluble so that the LDL cholesterol level could be determined by standard techniques. See, A. C. Parekh and D. H. Jung, Anal. Chem., 4_2, 1423 (1970) . When a soluble mixture was placed on a gel elec- trophoresis slab, only a single component was observed with a mobility equal to that of LDL.However, when the agglutination .reaction was carried out at 4°C, some VLDL, in addition to LDL, ■ was observed by gel electrophoresis .Those skilled in the art will recognize many equivalents to the specific steps, materials, tech¬ niques, etc. described herein. Such equivalents are intended to be included within the following appended claims.Industrial ApplicabilityThis invention has industrial applicability in clinical laboratories ' in the determination of LDL chol¬ esterol levels in blood plasma or other body fluids . | CLAIMS1. In a kit for determing LDL cholesterol in a body fluid, the improvement characterizing including in said kit a reagent containing a lectin which is a specific agglutinating agent for LDL.The improvement of Claim 1 wherein said reagent containing a lectin has been lyophilized and the kit additionally contains a reconstituting reagent containing an aqueous based or water-miscible solvent.3. The improvement of Claim 2 additionally including a cholesterol determining reagent.4. The improvement of Claim.3 additionally including a resolubilizing reagent comprising lactose in an aσueous solvent.In an assay for determining the LDL cholesterol level in a sample of blood plasma, the improvement comprising isolating LDL from other lipoproteins in said sample of blood plasma by selectively agglutinating LDL with a plant lectin and there¬ after determining the amount of cholesterol in said agglutinated LDL.6. An improvement of Claim 5 wherein said plant lectin comprises Ricinus Communis bean lectin,7. An assay for determining the LDL cholesterol level in a sample of blood plasma, comprising:B RE T a. agglutinating LDL in said sample of blood plasma with a plant lectin; b. separating agglutinated LDL from other lipoproteins in said sample of blood plasma; and, c. determining the amount of cholesterol in said agglutinated LDL.8. An assay of Claim 7 wherein the amount of agglu¬ tinated LDL cholesterol is determined by first relieving agglutination to resolubilize LDL cholesterol and subsequently detecting said re¬ solubilized LDL cholesterol.9. An assay of Claim 8 wherein said resolubilized LDL cholesterol is detected by an optical method.10. An assay of Claim 9 wherein said optical method for determining the amount of resolubilized LDL cholesterol is an optical absorbance technique.11. An assay of Claim 10 where in the agglutination of LDL cholesterol is relieved by contacting said agglutinating said LDL cholesterol with a sugar.12. An assay of Claim 11 wherein said sugar comprises galactose or lactose.13. A method of Claim 12 wherein said plant lectin com¬ prises Ricinis Communis bean lectin. | UNIV BOSTON; TRUSTEES OF BOSTON UNIVERSITY | SEARS B |
WO-1979000321-A1 | 1,979,000,321 | WO | A1 | EN | 19,790,614 | 1,979 | 20,090,507 | new | B07B13 | null | B07B13 | B07B 13/11B | PROCESS AND APPARATUS FOR SEPARATING PARTICLES BY RELATIVE DENSITY | A process and apparatus wherein a size-classified bed of particles is fluidized by agitating a supporting surface (50) with a gyratory motion to fluidize the particle bed. Particles are contacted with surfaces, e.g., vertically projecting surfaces (51, 62, 66, 68) movable with the supporting surface and defining two or more annular regions so as to impart sufficient fluidity to allow the particles to move within the particle bed and distribute themselves according to their relative densities. Particles are then permitted to move through openings (52, 70, 72) between these annular regions whereby the more dense particles tend to accumulate in one of the annular regions and particles of lesser density are displaced into the adjacent annular region (s). Provision is made for continuously extracting from the aggregate particle mass either or both those particles of lesser density and those of greater density whereby a continuous selective separation of particles according to density takes place. Various configurations are used to define annular regions within the particle bed and the flow of the more (or less) dense particles may be either radially inward or outward between such annular regions, depending upon the nature of the gyratory motion, and upon other factors more fully described herein, such as the dimensions of the annular regions, particle size and density and the frequency and amplitude of gyration. | PROCESS AND APPARATUS FOR SEPARATINGPARTICLES BY RELATIVE DENSITYRelated ApplicationsThis application is a continuation-in-part of my earlier application Serial No. 663,247, filed March 2, 1976 and now abandoned, which in turn is a continuation- in-part of application Serial No. 552,704, filed Febru¬ ary 24, 1975 and now abandoned, all three such applica¬ tions having the same title.Field of the InventionThis invention relates to the separation and classification according to relative mass and/or density of particles contained in an aggregate mass .of particles of various relative masses or densities. In particular, it relates to an improved process wherein gyratory motion is used to energize the particles to fluidize the par¬ ticle bed. It is particularly useful in the separation of dry particulate ores and minerals, where the process can be applied to upgrading. For example, the invention readily separates dense particles, such as gold, lead or other metal particulates from less dense sand or gravel of the same particle size. The invention is especially effective in separating dense particles from a homogen¬ eous flowable bed of particles of different density. Known processes for separating and classifying particles contained within an aggregate particle mass are truly numerous. Many of these processes are limited to separating particles according to size (classifying) or weight while others are effective in separating par- tides in accordance with their densities, irrespective of the size of-the particle. The present invention per¬ tains to the latter type of separation process, but can be used in combination with the other types of separa¬ tion techniques. One of the oldest methods for separating heavier materials from lighter crushed materials is the riffle board, or riffle pan in which crushed ore, for example, is placed upon a corrugated surface set at an incline and flushed with water. During separation, the riffle board is moved back and forth in directions nor¬ mal to the corrugations, or is otherwise vibrated so as to create relative motion between the particles and the riffled surface. The lighter ore tends to carry over the corrugations (riffles) farther from the point of feed than the heavier minerals, and the crushed materials therefore are carried by the water over the edge of the riffle board at different points.A serious disadvantage in the riffle board type of separation process is its requirement for a con- tinuous flow of fluid over the riffles and a high degree^ of unselectivity in attempting to separate out even the heaviest particles. In addition, the riffles are neces¬ sarily restricted in dimension and thus a limit is placed on the amount of material which may be separated in a given amount of time.Another technique for grading crushed ore par¬ ticles is found in U.S. Patent 3,349,904. There a rota¬ ting screen in the form of an inverted cone receives the aggregate particle mass while air is simultaneously blown upward through the screen to create an upward pressure. Heavier metal particles are intended to over¬ come the upward air blast pressure and be separated out of the mass by falling through the screen, while lighter rock particles are thrown upwardly and outwardly to the periphery of the screen due to centrifugal force. The major disadvantage in attempting to separate particles by this method is the high degree of complexity of the apparatus and the essential requirement for a source of pressurized air. Another obvious limitation is that material sized larger than the screen openings , even if having the selected density, cannot be handled. Further- - -more, although it may be possible to separate materials whose densities are grossly disparate, it is believed that the process is not sufficiently selective where the density of the desired material (such as crushed .ore) approaches the density of the waste material unless the particle size is carefully controlled.Processes such as that disclosed in U. S. Patent 2,950,819 use a gyratory separator (or classi¬ fier ) in which the particle mass is placed upon a vibratory screen which is designed to pass particles of all sizes smaller than the screen openings and irre¬ spective of the particles' densities. Separators of this type are usually operated to cause all over-size parti¬ cles, to move to the periphery of the screen and be dis- charged. It is possible, however, to operate such devices such that over-size particles do not discharge due to a tendency for them to move radially inwardly to the center of the screen where they are retained as is shown, for example, in U.S. patent No. 3,794,165 (FIGS. 7-10). In certain cases these separators are used to remove or recover particles entrained in a liquid wherein the liquid passes through the screen and the par¬ ticles are trapped by the vibratory screen and flushed down an outlet at the screen's center. In all cases, so far as is known, gyratory separators have not been adapted to or operated for separating particles in accordance with their relative ■ densities. Even in cases where particles are retained on the vibratory screen, no provision was made for separately segregating or extracting those remaining particles according to their density.One of the most widely used methods at present for extracting, ore particles of selected density from a larger particle mass is the so-called flotation process. This process is a wet process because it uses water as a carrier of the ore particles. The ore is first finely crushed into powdered form and then dispersed in the water carrier while oil or some other different liquid is passed upwardly through the aqueous flotation medium. Particles, depending upon their densities, are attracted to the liquid substance and are carried off and collected.Although the flotation process is capable of upgrading the crushed ore by a factor of 907o, while re¬ taining 907β of all the minerals, it is usually desirable that the ore be ground into extremely small particle size, e.g., No. 400 mesh (400 particles per inch). The production cost of mining and crushing ore to a state this fine is expensive. It is known, for example, to account for almost one-half the mining and recovery costs of certain metals. Furthermore, the process is usable only where there is an ample source of water, a resource which is often unavailable in sufficient quan- tity for carrying out the flotation step, and it is also polluting if the water carrier waste is discharged back into the source without cleaning.A yet more venerable separation method is gold panning, where a prospector places a small sample of placer in a shallow metal pan and gently swirls the pan to rid it of low density particles while retaining the heavier ones, This procedure is mentioned here because it is still in use by both amateurs and professionals. Panning is sometimes used in the field, for example, in order to separate gold dust from gravel cores drilled from the earth. As might be expected, panning is slow, tedious and unrewarding except for the most skilled prospectors.Still another known separation technique is__,O P| - based upon a mechanical concentrator known as the Denver Mechanical Concentrating Pan which duplicates the hand panning motion. This device consists of a series of classifying screens under which are placed several pans specially coated to trap the fine heavy materials (e.g., gold) . The first pan is metal coated with mercury to amalgamate free gold; the remaining pans receive the overflow from the first and are coated with a rubber matting covered with screening which acts like a riffle. The entire assembly is driven with an eccentric motion in order to swirl the material in water, which is added along with the particle mixture, to settle the mineral. Like other processes, this technique requires a flow of water and its collection capacity of the heavier fines is limited by the amalgamation and riffle capacity of the concentrating pans. It thus must be stopped period¬ ically and emptied of the' concentrated minerals.A similar principle is used in devices such as shown in U.S. Patent No. 1,141,972 to Muhleman, where a rotary tilting motion is imparted to a pan having a riffled floor surface. Concentrated ore is extracted from a hole in the center of the pan floor. Again, the motion of the pan is such that the waste material swirls about the edge of the pan and is discharged whereas heavier material gravitates toward the center due to the tilting.It is an object of the present invention to provide a method for separating particles in accordance with their masses or densities and which may be carried out in a dry particle bed.Another object of the invention is to avoid some of the disadvantages of particle separation tech¬ niques previously used, while permitting the use of uncomplex apparatus.ϋRH-4^OMPI Yet another object of the invention is to pro¬ vide novel apparatus and processes wherein particles are separated in defined annular regions in a particle bed. Among the additional objects of the invention is to provide methods and apparatus for separating par- tides by efficiently converting gyratory motion into a controlled motion of particles within a particle bed. More broadly, it is an object of the invention to pro¬ vide a novel way of fluidizing a dry particle bed where- by the movement and flow of particles within the fluid¬ ized bed is controlled in a way which permits segregation of particles according to relative mass or density.Summary of the Invention These and other objects of the invention are attained by disposing an aggregated mass of particles, which may have different densities, upon a supporting surface so as to form a particle bed. The particle bed is then fluidized by agitating the surface, together with other particle-contacting surfaces, with a gyratory motion having a circularly eccentric component and a vertical vibratory component sufficient to reduce the resistance of the particle bed to a degree that the par¬ ticles can move through the bed in desired directions, e.g., radially circularly and vertically. In the disclosed embodiments, particles in dif¬ erent annular (or circular) regions of the bed are con¬ tacted with annular reaction surfaces (e.g., vertically extending rings) movable with the supporting surface. These annular surfaces provide areas of frictional con- tact with the particles sufficient to impart to them a net energy or momentum causing particles of selected density to move through restricted openings to one of the annular regions for collection or removal. ThisOMPI movement of the particles comprises a net circularly inward or outward movement whereby particles of selected density move via the restricted openings from one annular region to another. The reaction surfaces may comprise, for example,•one or more concentric cylindrical walls or simply a high friction or grooved portion of the supporting sur¬ face. Particles are then permitted to move across the boundary between such regions whereby the energy or momentum of, for example, the more dense particles causes them to move inwardly or outwardly to the collection region and there displace particles of lesser density.Similar particle action can be obtained with a vertical column wherein the particle energy and/or pres- sure may vary from the bottom to the top of the column, and either the more dense or less dense particles can be induced to move from lower to higher levels in the column, where they may be extracted, as is hereinafter described. One phenomenon present in the invention is the tendency of more dense particles to move to given vertical levels in the bed, and this action is taken advantage of in some modes of operation.In accordance with other aspects of the inven¬ tion, the circular motion of the particle mass is con- trolled and directed by elements placed in the bed in order to accommodate a continuous addition of particles to the bed while extracting the particles of selected ^ densities. In general this motion is circular, but its direction and speed can be controlled to achieve a desired isolation of more dense particles from the less dense ones.The process is effective for upgrading other¬ wise uneconomic or marginally economic particulate ores and minerals. -For example, although extraction of the more dense particles in accordance with certain embodi¬ ments can result in extraction of less dense particles as'BURH4^O well, the extracted composite mass will be substantially upgraded to a degree where further separation or. ecovery of the dense particles becomes commercially feasible by known techniques.Description Of The DrawingsFor a complete understanding of the invention, together with the further purposes and advantages thereof, reference should be made to the following detailed inspec¬ tion of preferred embodiments, and to the drawin , where- in:FIG. 1 is a perspective view in partial cross- section of an apparatus which may be used for carrying out the process of the invention;FIG. 2 is a plan section view of the FIG. 1 apparatus;FIGS. 2A and 2B are cross-sectional views taken along the lines A,B-A,B of FIG. 2;FIGS. 3 and 4 are fragmentary plan section views of the FIG. 1 apparatus showing alternative forms of its particle bed-supporting surface;FIGS. 3A and 4A are cross-sectional views along the lines A-A in FIGS. 3 and 4, respectively;FIGS. 5 and 6 are respective plan section views of the apparatus of FIG. 1 showing different modifica- tions thereof for carrying out various operations in accordance with the process of the invention;FIGS. 5A-5B and 6A are cross-sectional views, taken along the lines A-A and B-B of respective FIGS. 5 and 6, and include pictorial representations of particles for explaining how they are separated therein;FIG. 7 is a cross-sectional plan view of an apparatus demonstrating further aspects of the process according to the invention wherein extraction of less dense particles occurs in a particle column;Bl)RE ^ OMPI FIG. 8 is a cross-sectional elevation view of the arrangement of FIG. 7, taken alon the line 8-8; and FIG. 9 is a perspective view in partial cross- section of a two-stage separation apparatus for separ- ating particles by density in accordance with the inven- • tion.Detailed Description Of Preferred EmbodimentsIn the process to be described, particles of selected density (e.g., most dense particles) contained in a mass of classified particles of various densities are separated by giving the particle mass a sufficient degree' of fluidity to allow the particles to move within the bed and to distribute themselves according to their densities. Specifically, the particle bed is fluidized by agitating a supporting surface for the particle bed with a gyratory motion effective to cause particles of selected density to move in a generally circular path from one annular region to another for collection or removal. The manner in which this is achieved will be explained in the ensuing description.When the particle ted is fluidized , it assumes many properties of a true fluid. For example, it flows and exerts fluid pressure, and it may exert a positive or negative buoyant force upon submerged ob- jects so as to create a particle flow up or down in the vertical direction. Additionally, the particle bed expands due to increased spacing between particles, thereby offering less resistance to the movement of par¬ ticles through the bed and permitting a relocation of classified particles based on their densities.Referring now to FIG. 1, the vibratory device for carrying out the process includes a cylindrical base 11 and a plurality of compression springs 13 circumfer- entially spaced about the upper rim 13a of the base for supporting a flat table 14. This table carries at its . center a cylindrical motor mount 15 which extends down into the center of the base 11. The motor 17 is sup¬ ported within the cylindrical motor mount 15 by a pair of annular flanges 18, such that the motor is rigidly affixed to the table 14. Vibrations induced by the motor are therefore transmitted directly to the table. A cylindrical spacing frame 20 secured by a clamping ring 21 at the periphery of the table, extends upwardly for supporting the upper section of the apparatus. The upper section comprises a particle-support¬ ing table 22, constructed for example of one-eighth to one-quarter inch thick steel or aluminum plating, and an upstanding cylindrical rim 23 provided with a discharge opening 24 leading to the discharge spout 26. The open- ing is disposed slightly above the level of the plate 22 so as to form an arcuate shoulder 24a preventing spill- out of any particles resting on the surface of the plate. The entire upper section is similarly clamped by the ring 27 to the rim of the lower frame 20.A shaft 30 extends from each end of the motor to which weights 31, 32 are fixed. It will be seen that the weights project horizontally outwardly from the shaft 30, and the radial angle between the axes of the two weights is adjustable by shifting the angular posi¬ tion of the weight 32 on the shaft 30. In this manner, the upper weight 31 can be made to lead the position of the lower weight 32 by an adjustable angle. Adjust¬ ment of these weights alters the characteristic of the resultant vibratory motion, as is understood by those skilled in the art. • Preferably, the weight 32 is adjusted so as to provide a substantial lead angle, e.g. , of about 80°-90°. This appears to bring about the maximum fluidity in the particle bed creating a sufficient weightlessness or inter-particle spacing so as to mini- mize the resistance of the particle bed to particle movement therewi hin, and to impart an upward thrust to the bed, so that particles of greater density will move upward by the absorption of greater energy than particles of lesser density. By' the same token, this weight set¬ ting imparts an inward thrust, or throw, to particles contacted by the plate and the annular rim 23. On the - other hand, a weight setting of 0° lead angle imparts an outward thrust to the particles on the plate, and re¬ sults in less upward thrust to the particles.The movable components of the separator assem- bly, as shown in FIG. 1, assume a gyratory motion, i.e. , the motion has both a circularly eccentric component and an oscillatory vertical component. The combination of these two motion components enables energy imparted to the moving elements to be converted with maximum effi- ciency into the sought-after motion of particles placed upon the table element 22. In general, the components are sufficient in magnitude to reduce the resistance of the mass to translational movement of the particles. Increasing the lead angle of the upper weight 31 tends to increase the vertical oscillatory component of gyra¬ tory motion, as does increasing the size of the weights. Higher weight sizes also accentuate the eccentric motion displacement from center. Increasing the mass of the lower weight 32 produces a greater upward thrust and permits the use of a deeper particle bed.In carrying out the process of the invention with the device of. FIG. 1 (which will be understood is representative of the kind of device usable) together with certain additional elements to be described, par- tides are placed upon the table 22, as indicated by the arrow 35, and may be extracted, for example, through the opening 24 and spout 26, as indicated by the arrow 36 Other locations for extraction are also possible. Des¬ criptions of various gyratory devices of this type, commonly referred to as separators, will be found in U.S. Patent Nos . 3,794,165, 3,399,771 and 2,950,819.As earlier mentioned, the circular eccentric motion combined with the vertical oscillatory motion causes the particle mass placed upon the table 22 to move radially either toward the table's center or toward the periphery, depending on the angular displacement of the eccentric weights 31 and 32. If the surface 22 were a relatively smooth one, particles could also tend to move in a slow migratory circular motion in the same direction as the eccentric motion, i.e., in the direction of revolution of the motor weights 31, 32. The particle bed, in this case, does have a certain degree of fluid¬ ity which can be enhanced and particle flow controlled by making use of the natural tendency of individual par- tides to spin in a direction counter to the direction of circular eccentricity, with the particle spin axis being generally normal to the supporting table 22. It has been found that this spin tendency can be converted into a circular motion of the particle mass. Moreover, the circular motion can be used to control the flow of particles within the fluidized bed.This conversion of particle spin into a circu¬ lar translational motion is accomplished by contacting the particles with a reaction surface of sufficient area. This surface may comprise surface portions at the bottom of the particle bed having components of projection normal to the plane of the surface. When the spinning surface of a particle contacts such vertical surface portions, the particles react against them and, in essence, bounce off them and thereby are given transla¬ tional circular motion. The reaction surface might also and desirably will include a cylindrical wall wherein the particles react against the inner surface of the wall and are given additional energy of linear motion. From tests conducted with vibratory devices like that depicted in FIG. 1, it appears that an effi¬ cient configuration, of the surface supporting the par¬ ticle bed is one which is provided with a series of con¬ centric grooves, scorings, or projections 40 which are contacted by the particles at the bottom of the particle bed. These grooves, scorings, or projections clearly indicate in the plan view of FIG. 2, may be spaced apart by any desired amount, the closer spacings generally giving a higher degree of fluidity to the particles. I have found that inter-groove spacings of between 1/4 inch and 3/4 inch.provide the desired fluidization of a par¬ ticle bed containing particles of between 1/16 inch and 1/8 inch in diameter. As discussed hereinafter, the reaction surface might also comprise an annular vertical surface surrounding a region of the particle bed, or a combination of annular surfaces, or an annular surface in conjunction with the supporting surface grooves and pro¬ jections.The cross-sectional view of FIG. 2A shows the shape of triangular grooves which are cut into the sur¬ face of the supporting surface 22. In the modified form of surface, seen in FIG. 2B, the particle-contacting sur¬ faces comprise projections rising from the surface 22a wherein each projection has a generally rectangular cross-:section with rounded upper edges.Yet another form of particle contacting projec¬ tions is seen in FIGS. 3 and 3A. There, the upper sur¬ face 22a of the supporting table has a multitude of irregular smaller projections 41 extending upwardly. In FIGS. 4 and 4A, projections in the form of a multitude of rectangular mutually orthogonal cleats are present for contacting particles at the bottom of the particle bed and imparting to them a translational circular motion. The surface configurations of FIGS. 3, 3A and 4, 4A are not as efficient as those shown in FIGS. 2A andO PI ~ ~™ 2B in imparting a circular motion to the particle mass, and the rotational velocity of the particle mass on surfaces such as these is much less than the configura¬ tions of FIGS. 2A and 2B. When an aggregate mass of particles is placed upon the supporting table 22 having the surface configu¬ ration illustrated, for example, in FIG. 2A, and with the eccentric-weights 31, 32 set for a 90° lead angle, the particle mass is given a high degree of fluidity with a strong net inward movement and accumulation of par¬ ticles, as well as a circular motion counter to the direction of the eccentric component of gyration. In the embodiments described herein, for reasons which are not thoroughly understood, particles of highest relative density in a classified particle bed generally tend to ove with other particles into a collection region and remai there. Particles of lesser density are displaced in that region by the highest density particles, It is believed that this region is the point of lowest total pressure. To investigate this phenomenon in more detail, reference is made to FIGS. 7-8.FIGS. 7-8 illustrate a basic yet effective con¬ figuration of the apparatus for carrying out the separa¬ tion process of the invention. FIG. 7 is a plan view similar to FIG. 2 showing a bed supporting table element 43 and circumferential rim 44 which are understood to be affixed to the gyratory separation device of FIG. 1 in place of the elements 22, 23. The machine used in this case is one available from Russel Finex Company, Mount Vernon, New York, equipped with a 3/4 hp motor at 1140 rpm. The eccentric-weights 3i, 32 were set to provide for an inward throw of the particles.FIG. 8 is an elevational view in cross-section of this configuration. The table surface 43a is option- ally provided with a series of circular projections 43b similar -to those shown in FIG. 2A. These projections • 'BUREΛ^OMPI ~~~ ~ are present only in the annular region next to the rim 44 and, together with the rim, are effective to induce counter-eccentric circular motion of the particles in that region. The remaining portion of the surface 43a is essentially smooth, offering little frictional contact with the particles. The particles in the bed supported by this part of the table will ordinarily follow a slow circular path in the same direction of the eccentric motion component of gyration. Another annular rim 44a of smaller diameter is affixed to the element 43 so as to form an annular channel 44b which serves as a temporary collection zone for upgraded material, as will be explained. Extending upwardly from a level adjacent the central portion of the surface 43a is a smaller annular rim, or collar, 45 which is spaced from the surface to form a narrow annular gap 45c, thus providing an area of limited communication between the interior and exterior of the collar. The collar 45 is affixed to the table 43 by any suitable means (as by brackets, not shown) so as to be movable therewith. Extending upwardly midway into the space at the interior of the collar is an extraction duct 45d, only a portion of which has been illustrated, leading to points outside the particle bed contained on the table 43. The collar provides a reaction surface 45e for particles at its interior so as to impart to them a counter-eccen¬ tric circular motion.Associated with the rim 44a is a chute 44c for the introduction of raw material to be processed, indicated by the arrows 46 designating the direction of raw material flow (FIGS. 7 and 8) . The chute 44c may be flexibly coupled to the rim 44a and supported externally of the agitator, if desired, to reduce imbalance of the gyratory table 43a. Material introduced into the chute flows through rectangular orifice 44d leading into the^BΪJRE ^O region of higher circular particle velocity in the fluid¬ ized bed of particles. Extraction of more dense par¬ ticles occurs through the exit hole 48a and exit chute 48b leading from the annular collection zone 44b , as shown by the arrows 47d. In several runs using this configuration, mixed particles containing, for example, ungraded beach sand and lead shot particles of greater size to be separated were added through the chute 44c to the aggregated par- tide mass in the annular outer region of the bed, as in¬ dicated by the shaded arrows 46. Added particles flowed onto the fluidized bed surface through the opening 44d in the rim 44a. Particles in that outer annular region of the fluidized bed were contacted by the reaction surface provided by the rim 44a and the surface projections 43b. This resulted in a transfer of energy to the particles in that region so as to induce a circular translational particle motion counter to the direction of eccentric gyration, as noted earlier. This motion is shown by the shaded arrows 47a in FIG. 7. (Particles are not illus¬ trated in FIG. 8.) Particles in the adjacent inner annular region, however, had a very much lower velocity of rotation, sometimes even in the direction of the eccentric gyration (as shown) . The velocity of the cir- cular motion (indicated by the white arrows 47b) in this adjacent region is thus negative relative to (i.e., less than) the counter-eccentric velocity in the outer annular region. As a result of the foregoing, a boundary (shown by the phantom line in FIG. 7) between these two velocity regions appeared to establish a natural barrier to the inward movement of the lead shot particles, even though the eccentric-weights were set to provide an inward throw, or thrust, upon the particle mass as a whole. Thus, the denser particles tended to remain in the region of highest circular particle velocity. The densest particles (shown black in FIG. 8) thus displaced less dense (white) particles. The densest particles also had a tendency to migrate toward the surface of the bed. The reasons for this are not perfectly understood; however, this may occur because of their greater upward inertia provided by the upward thrust of the gyratory table ele¬ ment 43. It may also be the result of the small vertical gradient in circular velocity which increases from bottom to top of the bed. In any case, even those dense par- tides which may be present in the region inward of the barrier tend to move both to the surface and outwardly to the outer annular region adjacent the rim 44a. Advan¬ tage is taken of these phenomena in the extraction of the densest particles. To this end, the rim 44a includes one or more slots 44e cut into its upper edge through which particles in the upper stratum of the fluidized bed can flow into the collection zone 44b. This extraction path is shown by the shaded arrow 47d. From the channel 44b, the particles flow into the opening 48a and extraction duct 48b. While only one slot 44e has been illustrated, it is possible to provide further similar slots in the rim 44a, mutually spaced circumferentially. Use of the extraction scheme shown in FIGS. 7-8 will result in some removal of less dense particles along with the densest particles; however, the extracted mix¬ ture is considerably upgraded, containing a much higher percentage of the desired dense material, for example, a particulate mineral. The upgraded material can, bf course, be recycled through the same procedure for fur- ther upgrading, recycling taking place either in another stage (not shown) below that illustrated, or in a sepa¬ rate apparatus.In FIGS. 7-8 less dense particles, displaced by the dense particles, migrated inwardly from the inlet opening 44d to the adjacent annular region from which_OMPi_ ■ particles (shown black in FIG. 8) thus displaced less dense (white) particles. The densest particles also had a tendency to migrate toward the surface of the bed. The reasons for this are not perfectly understood; however, this may occur because of their greater upward inertia provided by the upward thrust of the gyratory table ele¬ ment 43. It may also be the result of the small vertical gradient in circular velocity which increases from bottom to top of the bed. In any case, even those dense par- tides which may be present in the region inward of the barrier tend to move both to the surface and outwardly to the outer annular region adjacent the rim 44a. Advan¬ tage is taken of these phenomena in the extraction of the densest particles. To this end, the rim 44a includes one or more slots 44e cut into its upper edge through which particles in the upper stratum of the fluidized bed can flow into the collection zone 44b. This extraction path is shown by the shaded arrow 47d, From the channel 44b, the particles flow into the opening 48a and extraction duct 48b. While only one slot 44e has been illustrated, it is possible to provide further similar slots in the rim 44a, mutually spaced circumferentially.Use of the extraction scheme- shown in FIGS. 7-8 will result in some removal of less dense particles along with the densest particles; however, the extracted mix¬ ture is considerably upgraded, containing a much higher percentage of the desired dense material, for example, a particulate mineral. The upgraded material can, of course, be recycled through the same procedure for fur- ther upgrading, recycling taking place either in another stage (not shown) below that illustrated, or in a sepa¬ rate apparatus.In FIGS. 7-8 less dense particles, displaced by the dense particles, migrated inwardly from the inlet opening 44d to the adjacent annular region from whichOMPΪ they were removed, as follows:As the volume of less dense particles in the adjacent region builds up, these particles reach the gap 45c at the collar 45 and travel to the collar's interior. There they are contacted by the collar surface 45e and - are induced to rotate in the counter-eccentric direction (arrows 47c) . Particles outside the collar 45 were forced inwardly into the higher (counter-eccentric) velocity flow (arrows 46a in FIG. 8). Once inside the collar, particles not only move circularly, but also flow upwardly toward the spout 45d, where they are extracted.In review, particles of highest density accu¬ mulated and were extracted from the outer annular region next to the rim 44, while particles of less density moved inwardly in the adjacent region and eventually were extracted from the particle column bounded by the collar 45.The theoretical explanation for the behavior . of the particles is not entirely understood. It is be- lieved, however, that the particles move in the fluidized bed under the influence of pressure differentials which are established by a combination of forces including those resulting from the circular translational motion, the inward thrust generated by the eccentric motion of - the plate together with the apparently greater upward in¬ ertia of the more dense particles. Thus, in some instan¬ ces, the particle motion seemed to comply with the laws of dynamic energy of motion. Whether the apparent highest relative velocity in the region of accumulation to dense particles is a causative factor of that accumu¬ lation or simply an observed phenomenon in this embodi¬ ment is not certain.Where the particle bed has appreciable depth, the hydrostatic pressure also may be taken into account as in, for example, the interior of the column bounded by the collar 45. Dynamic pressure and the constantfURE^Λx»r_¥ they were removed, as follows:As the volume of less dense particles in the adjacent region builds up, these particles reach the gap 45c at the collar 45 and travel to the collar's interior. There they are contacted by the collar surface 45e and are induced to rotate in the counter-eccentric direction (arrows 47c) . Particles outside the collar 45 were forced inwardly into the higher (counter-eccentric) velocity flow (arrows 46a in FIG. 8). Once inside the collar, particles not only move circularly, but also flow upwardly toward the spout 45d, where they are extracted. In review, particles of highest density accu¬ mulated and were extracted from the outer annular region next to the rim 44, while particles of less density ~'' moved inwardly in the adjacent region and eventually were extracted from the particle column bounded by the collar 45.The theoretical explanation for the behavior of the particles is not entirely understood. It is be- lieved, however, that the particles move in the fluidized bed under the influence of pressure differentials which are established by a combination of forces including those resulting from the circular translational motion, the inward thrust generated by the eccentric motion of ' the plate together with the apparently greater upward in¬ ertia of the more dense particles. Thus, in some instan¬ ces, the particle motion seemed to comply with the laws of dynamic energy of motion. Whether the apparen highest relative velocity in the region of accumulation to dense particles is a causative factor of that accumu¬ lation or simply an observed phenomenon in this embodi¬ ment is not certain.Where the particle bed has appreciable depth, the hydrostatic pressure also may be taken into account as in, for example, the interior of the column bounded by the collar 45. Dynamic pressure and the constant^BUREΛ /^ - addition of dynamic energy to the particles by agita¬ tion are further factors tending to. complicate the ana¬ lysis. For example, if a strong inward momentum is im¬ parted to particles at the rim 44e, a sufficient dyna- ic inward pressure may be exerted on all particles (in- , eluding dense particles) , and this could cause an un¬ desired loss of some of the dense particles to the cen¬ ter of the bed in the FIGS. 7-8 arrangement. For this reason, it is desirable to adjust the dimension of the annular gaps below the collar 45, as well as the col¬ lar height, such that the flow into the particle column is gentle enough not to disturb the essentially circu¬ lar flow at the bed's perimeter.Although the configuration shown in FIGS. 7-8 , represents one on a laboratory scale, using a 22 inch diameter table 43 driven by a 3/4 hp motor (weights set at maximum amplitude) wherein the projections 43b ex¬ tended inwardly approximately 2 inches from the rim and the collar 45 was 6 inches in diameter and set 1/2 inch from the table surface 43a, small lead shot admixed with sand resulted in almost 1007o recovery of all lead shot with a flow rate through the apparatus of 2000 pounds per hour.Certain further experiments with the apparatus revealed various facets of particle behavior, including their ability to separate in the fluidized bed. In one experiment a cylinder, similar to the collar 45 and about 4-1/2 inches in diameter and 6 inches high, was fixed to the table 43 and filled with sand. A second, smaller cylinder of about 3 inches in diameter was in¬ serted into the sand to a depth of four inches and r.p.m. readings were taken inside the sand. Within the smaller collar, the circular motion of sand measured about 10 r.p.m'-. (94 inches/minute at the periphery). In the two-inch space below the inserted collar the -20- εpeed measured about 45 r.p.m. (636 inches/minute at the periphery). When lead shot was added to the sand, all the lead shot was recovered from the sand at the bottom of the fixed cylinder where the greatest velo- city was present. When the inserted smaller collar was • removed, the lead shot rose to the top one-quarter of the bed inside the cylinder.FIGS. 5- nd 6 illustrate how further physical elements can be made to react with the particle bed so as to obtain controlled flow of the particle mass.The plan view of FIG. 5 and the corresponding cross-sectional elevation view of FIG. 5A shows the loca¬ tion of flow controlling elements. A cylindrical col¬ lar or ring 51 extends upwardly from the center of the ~ ' particle supporting surface 50. This collar has a verticle gap 52 extending down to the surface 50, such that particles are free to enter the region inside the collar 51 through the gap 52, but not underneath the collar as in the embodiments of FIGS. 7-8. A second collar in the form of an annular ring 54 radially spaced from the collar 51 likewise extends upwardly from the particle-supporting surface. It will be understood that the top surface 50 of the plate 49 bounded by the collars 51, 54 includes the annular grooves or ridges ' (not, shown) of the type depicted in FIGS. 2A and 2B.Particles are added to the particle bed either at the center of the open collar 51, as illustra¬ ted by the designation X-, in FIG. 5A, or at the location designated X^, which is between the collar 51 and the ' annular ring 54. Particles added to the particle bed at either location assume a circular motion both in the . annular region at the interior of the ring 51 and in the annular region between the ring 51 and the ring 54, due to the eccentric gyratory motion of the surface 50 and rings 51, 54, which provide reaction surfaces to convert the particle spin energy into rotational translational energy of the particle mass. Any denser particles which are in the annular region between the rings 51 and 54 will tend to migrate toward the interior of the collar 51, and will do so upon reaching the gap 52.Thus, there is an exchange of dense particles for less dense particles at the center of the fluidized bed, with the result that denser particles trade positions with the less dense particles and tend to remain there. As more particles are added to the central portion of the particle bed, a point is reached when the less dense particles begin to overflow the impedi¬ ment of the annular ring 54. These overflowing parti- cles reach the annular region radially outside the ring 54, and, finally, the discharge opening 58 and the ex¬ tracting spout 60. Thus a continuous flow may be es¬ tablished by adding particles continuously to the cen¬ ter of the bed, and extracting the overflowing less dense particles from the spout 60. For continuous flow operation the diameters of the rings 51, 54 are selected as noted already so as to maintain a higher rotational particle flow inside the ring 51 than in the region be¬ tween rings. This flow relationship aids the tendency of particles to migrate toward the center of the bed where the dense particles may exchange position with the less dense particles and be collected. This inward migration that is aided by the circular flow relation¬ ship is caused by the angular displacement of the eccen¬ tric weight setting which, in all of the embodiments described herein, is 80°-90° lead to provide a net in¬ ward throw of the particles to the center. The par¬ ticle flow in the vertical plane from the central point, where particles are added-, to the extraction spout 60 is seen in the illustration of FIG. 5A, the black particles representing the densest particles and the white particles representing less dense particles. In the drawings the more dense particles are shown to he resting at the bottom of the bed. This is a simpli¬ fied case, and in practice the more dense particles may be suspended at levels below the surface due to the ef¬ fects previously noted, namely, the greater upwards inertia given the dense particles.In one embodiment, the various elements of the vibratory apparatus depicted in FIGS. 5 and 5A may have the following dimensions and characteristics:Collar 51 (diameter) 4 inches Opening 52 (width) 1-1/2 - 2 inches Annular ring 54 (diameter) 7 inches Plate 49 (diameter) 18 inches Outer frame 62 (height) As desired Motor hp 1/4Motor rpm 1140Weight lead angle 80°-90°The configuration of FIGS.. 5 and 5A was suc- cessfully used to obtain nearly 1007o recovery in two minutes' time of 35 No. 2 lead shot from one gallon of sand ranging in particle size from between 1/16 and 1/8 diameter. The shot, after separation, was con¬ centrated at the center of the fluidized bed in a volume of less than 57o of the volume of starting material add¬ ed to the fluidized bed.In the process which has been described, it is not absolutely essential that the annular regions defined by the rings be perfectly circular or that they have common centers. It should accordingly be under¬ stood that the term concentric , as used herein, desig¬ nates configurations wherein annular regions surround each other successively oμtwardly of the center of motion, FIG, 5, in conjunction with FIG. 5B illustrates yet another arrangement of elements by which a different effect of the fluidized bed may be realized. In FIG. 5, the phantom lines represent a further annular ring 63 generally concentric with the open ring 51 and close¬ ly spaced to this ring so as to form therewith a narrow annular channel 65.- The ring 63 extends only partially into the fluid bed so as to leave a narrow cylindrical gap between the bottom portion 63a of the ring and the surface 50 of the gyratory plate 49. More¬ over, the ring 63 is not affixed to the table element 63, but is loosely held in place by suitable means or spacers (not shown) . As a consequence, the ring 63 does not transmit energy to the particles; in fact, it ex¬ tracts energy from and slows down the particles bounded thereby. Particles are added to the particle bed at the interior of the open ring 51 (at point X-,) , as best seen in FIG 5B.The effect of the intermediate annular ring 63 is to induce a flow of the particles from the center of the ring 51, through the opening 52 in that ring, and thereafter underneath the intermediate ring 63 and into the annular region between the ring 63 and the ring 54. As before, denser particles tend to remain at the in¬ terior of the rings 51,54. Less dense particles, never¬ theless, are swept out through the op.ening 52, under- neath the ring 63, and over the collar 54. When opera¬ ted in this manner, the apparatus of FIG. 5 accomodates continuous feeding of particles to the particle bed at the center of motion and continuous extraction of the lighter (less dense) particles at the periphery of the particle bed. The close spacing of the rings 51 and63 (which may be in the range of .25 -.75 when handling particles up to .25 in diameter) appears to slow con¬ siderably the circular particle motion in the channel 65. reduction in the rotational velocity of particles in- side the ring 51 is also observed when the ring 63 is_ ιm_ inse ted.It is important to note that the floating ring 63 exerts yet another influence, and that is to slow down the particle velocity more at the upper level of 5 the bed than at levels immediately above the surface 50. The most dense particles tend to remain within the col¬ lar 54 at the bottom of the fluidized bed rather than being caught up in the overflow and swept out into the adjacent region outside the collar 54. It is according-10 ly possible to control the velocity gradient vertically in the fluidized bed by such means as the floating ring 63 or other selective energ -extracting elements which contact the particles.In FIG. 5B, as the spacing between the ring 6315 and the surface 50 is increased, there is a concomitant ~ lessening of drag and reduction of pressure in the annular channel 65; and a lesser rate of flow of par¬ ticles from the interior of the ring 51 to the exterior of the ring 63 occurs.20 At this juncture, it should be pointed out that the flow of particles in the bed can also be induced radially inwardly in the same manner. If, for example, the ring 63 were larger in diameter such that a narrow annular channel were formed adjacent the inner surface25 of the ring 54, particles would flow radially inwardly underneath the ring 63 and toward the center of the par¬ ticle bed. It has been found that, with the configura¬ tion of annular rings shown in FIGS. 5 and 5B, reason¬ ably good recovery of the densest particles is achieved.30 FIGS. 6 and 6A illustrate a different configu¬ ration of physical elements for controlling and direct¬ ing particle flow. In this configuration also, a plu¬ rality of generally concentric annular regions is estab¬ lished between the concentric rings 61, 66 and 68; how- >-> ever, the entire surface 50 is.provided with particle- reactioή projections of one of the types represented in FIGS. 2A, 2B, 3A and 4A. In one embodiment which was found to be effective, the rings 66, 68 were dimensioned so that the circular particle velocity progressively increases from the outer to inner regions of the bed. • The rings have respective openings in their vertical walls so as to permit radially inward migration of the particles in the- fluidized particle bed. Thus, the ring 51 is provided with an opening 52, the ring 66 has an opening 70 and the ring 68 has an opening 72 through which the particles may flow. The arrows in FIG. 6 outline the general flow pattern of particles within the particle bed. As best seen in FIG. 6A, particles are continuously added to the particle bed in the annular — region between the rings 51 and 66 (this location being designated by X in FIG. 6).The arrangement of open rings of the foregoing configuration results in a circular motion of the parti¬ cle mass within the annular region inside the ring 51, as well as within the regions be'tween the rings 51 and 66, between the rings 66 and 68 and between the ring 68 and the outer frame 62.In operation, with the configuration of ele¬ ments shown in FIGS. 6 and 6A, the relatively dense ' particles tend to migrate inwardly. The more dense particles collect inside of the ring 51, whereas less dense particles are displaced in the particle mass radially outwardly through the respective openings 52, 70 and 72 into the outer annular regions. If desired, the height of the rings 66, 68 may be reduced in order to facilitate removal of the less dense particles by permitting them to flow over the top of these rings. In one preferred configuration of elements following the arrangement of FIGS. 6-6A, five circular concentric rings were used. Each ring with the excep- BURE cTJ3 PI_ - - tion of the outer one, had a narrow vertical aperture serving as an area of communication between adjacent channels in the particle bed. The aperture in the center ring was 3/8 wide and 2 high; the apertures in the re- maining apertured rings were 3/8 wide and 1-1/2 high, • as measured .from the smooth floor of the plate 49, The dimensions of the rings were as follows:Diameter HeightInnermost ring #1 5 inches 7 inches Ring #2 7-1/2 inches 2 inchesRing #3 9-1/2 inches 2 inchesRing #4 11 inches 2 inchesRing #5 * 12 inches 2 inchesThe inter-ring spacing (i.e., transverse channel dimen- - sion) thus progressively increased from the outer peri¬ phery to the inner ring as follows: 1/2 inch, 3/4 inch, 1 inch, 1-1/4 inches.In several tests using a batch of 100 pounds of -30+15 mesh silica sand containing a few grams of .11 inch diameter lead shot, more than 907. of the lead shot was collected and recovered in less than 10 pounds of sand in the region inside the center ring, using a test flow rate (rate at which sand/lead shot mixture is added to the particle bed) of 30 pounds per minute. , The sand/lead shot mixture was added at the point illustrated in FIGS. 6-6A. To facilitate the addition of the particle mixture at this point, a har¬ row apron, extending horizontally from the center.ring at a height of 2-1/2 above the plate 49, was used to break the fall of particles into the particle bed. Means may be used to guide the particles onto the apron as, for example, a cylindrical collar affixed to and spaced outwardly from the center ring.In this five-ring embodiment, the mode of operation and the manner of separation occurred as des- cribed in connection with FIGS. 6-6A. The circular ve¬ locities of particle flow, however, were difficult to measure. There was an apparent counter-eccentric parti¬ cle flow in the channels at lower levels of the particle bed, to the extent that flow could be measured with a probe thrust into the bed. However, the surface of the particle bed in the channels between rings exhibited con¬ siderable agitation, or turbulence, and no reliable veloc¬ ity measurement could be made. In the center ring, how- ever, there was a counter-eccentric circular motion that was observably faster than the apparent circular velocity in the channel adjacent this ring.During operation, the apertures in the rings were below the surface of the particle bed, and less -_, ense particles flowed radially outwardly over the tops of the 2-inch high rings for continuous extraction of the less dense particles from the region defined between the non-apertured 12-inch ring and the rim 62.To achieve the rate of separation specified above, a Kason vibratory machine (similar to FIG. 1) was equipped with a 1/3 hp motor operating at 1140 r.p.m. , and with a weight setting of 90° lead loaded to capacity of the machine.Thus, in the embodiments of FIGS. 6, 6A, it will be seen that the flow of particles is generally radially inward. The migration of particles is restric¬ ted between adjacent annular regions except at peri¬ pherally displaced openings (72, 70, 52) between these adjacent regions. This configuration forces particles migrating within the fluidized particle bed from one annular region to another annular region to follow a circular path before reaching an opening interconnecting adjacent regions. As a result, the particles are given a longer residence time in the fluidized bed and, conse- quently, the more dense particles have adequate time to separate out as they travel progressively inwardly. - -The process of the invention is ideally suited not only for separating particles in a single operation, but also for separating particles in separate stages. One apparatus in which multi-stage separation can be accomplished is illustrated in FIG. 9. There, in two •separation stages 80, 81 are vertically superimposed so as to be agitated by a common eccentric agitator of the type described above in connection with FIG. 1. The first stage is comprised of the elements shown in FIG.6 and like numerals (followed with a prime mark) have been assigned to the various elements. In addition, the upper stage 80 is provided with a central opening 83 through the plate 49 for passing the separated heavy particles to a chute 85 leading to the second (lower) ~ stage 81, this stage including a pair of concentric rings 86, 87 extending upwardly from the bed-supporting plate 84 having circumferentially spaced vertical gaps 88, 89 similar in configuration and location to the rings 51, 66 in FIG. 6. Though not shown in FIG. 9, the central opening should be provided with a flow restric¬ tive element such as a low standpipe or collar such as shown in FIG. 8. Separation in the two stages takes place as described above in connection with FIG. 6.In order to extract the scalped waste material • fro the first stage, a domed plate 90 disposed under¬ neath the plate 49*receives less dense particles dis¬ charged from the openings through the plate 49 and leads them to the discharge spout 92. As clearly illustrated, the chute 85 passes through the sloping plate and de- posits the more dense particles from the first stage in the annular region between the rings 86, 87. The less dense particles and waste material from the second stage exit from the lower discharge spout 93.It will he understood that combinations of stages other than that shown for illustrative purposes - - can be effectively used, and that further separation of the extracted less dense materials can be similarly effected in the same manner in a second stage of separa¬ tion. Moreover, it is preferable that all particles in the particle bed be classified beforehand so that an evenness of particle size is obtained. This ensures that dense particles to be separated will have greater mass than the less dense particles. To that end, apparatus for carrying out the process may incorporate conventional separation screens.Although the invention has been described with reference to specific processes and apparatus which have been carried out successfully on a small scale using experimental apparatus, it should be understood that the process is not limited to any specific appara¬ tus for carrying out the invention. There are numerous ways in which a fluidized bed might be controlled for separating particles of specified relative density by the use of specially designed elements placed within the fluidized bed. For example, the flow-controlling ele¬ ments might be made sloping and may take forms other than those disclosed herein to fit particular needs. Addi¬ tionally, the bed-supporting surface need not be per¬ fectly planar, and might have the form of an inwardly or- outwardly sloping conical wall, or yet other types of sloping geometries for taking advantage of gravitational force on the particle mass. As a further example, the bed-supporting plate can be covered wit a resilient layer which can be depressed slightly by the weight of the particles thereon so as to obtain the desired con¬ version of spin into translational circular particle movement. .It-,should also be noted that while the inven¬ tion is ideally suited for separation in a dry particle bed, i.e., one in which no supplemental fluid flow is0MP_ -30- required, separation can be effected though the particle surfaces are wetted as long as particle mobility is not eliminated by such wetting. Furthermore, the term particle herein is not used in its strictly literal sense and does not necessarily connote minute or small particles, since the invention might be applied to separation and classification of fragmentary materials over a great range of sizes including stone, rock and minerals (e.g., coal) in chunk form. It should be un- derstood that where the term particle velocity is used, reference is being made to the velocity at levels below the surface of the particle bed. In some instances, for example, particles on the surface appear to flow in a direction opposite to particles below the surface. No attempt has been made to suggest all fore¬ seeable modifications and variations which might occur to those skilled in the art. Thus, for purposes of explanation, all embodiments and operative process modes described above have employed vibratory machines wherein the eccentric weights were set to provide a substantial lead angle. But other weight settings can be used. Thus I have also used a 0° lead angle to achieve separa¬ tion. In that case the dense particles collected in the outermost channel at the periphery of the particle bed'. Circular velocity of the particles could not be measured, and it is quite possible that the particles were influenced more by the net radially directed thrust imparted to them by the eccentric component of gyratory motion than by any forces the circular velocity may have exerted. All such modifications and variations are in¬ tended to be encompassed by the appended claims. | . process or separat ng part c es o se ecte relative density from an aggregated mass of particles of se¬ lected size having different densities, comprising the steps of: disposing the aggregated mass of particles upon a supporting surface to form a particle bed; agitating the supporting surface with a gyratory motion having a circularly eccentric motion component and an oscillatory vertical component suffi¬ cient to fluidize said bed and thereby substantially reduce the resistance of the particle bed to transla- tional movement of particles therewithin; contacting the particles in said bed with vertical reaction surfaces movable with the supporting surface and defining at least two annular regions within the bed, one of said regions forming a zone for the re¬ tention .of particles of relatively greater density said supporting and reaction surfaces providing areas of contact with said bed sufficient to impart to the par¬ ticles forces causing them to move in paths having a net radial direction component; providing a restricted area of communication through at least one vertical reaction surface between adjacent annular regions so as to permit particles in said fluidized bed to move across at -least a portion of the boundary between said annular regions, whereby par¬ ticles of greater relative density move through said restricted area of communication into one. of said annular regions for collection, particles of less rela¬ tive density being displaceable from said collection region into an adjacent annular region.2. The particle separation process of claim 1, further comprising the step of: extracting from the fluidized bed at least a portion of the^less dense particles at a given location within said adjacent region.3. The particle separation process of claim 1, further comprising:OMPI — -32- adding particles to said fluidized bed in one annular region while extracting less dense particles from said fluidized bed in a different annular region. 4. The particle separation process of claim1, wherein said adjacent region surrounds said collec¬ tion region, the process further comprising! adding particles to said fluidized bed in one of said annular regions, and extracting less dense particles from the bed in another of said annular regions, whereby particles of greater relative density collect in the fluidized bed in said collection region while particles of lesser rela¬ tive density tend to be displaced outwardly from said collection region into said other annular region for extraction.5. The particle separation process of claim 1, further comprising: adding particles to said fluidized bed whereby added particles of greater relative density tend to migrate into said collection region while particles of lesser relative density tend to be displaced therefrom by the particles of greater relative density and move into other annular regions, and , extracting particles of less relative density ' from one of said other annular regions.6. The particle separation process of claim 1, further comprising: adding particles to the fluidized bed in an adjacent region while• extracting particles from said collection region.7. The process of claim 1, wherein said collection region is located generally in the center of gyratory motion of the fluidized particle bed.OMPI- -33-8. The particle separation pi-ocess of claim 7,- further comprising: extracting particles of lesser relative den¬ sity from said fluidized bed at a radial location re- mote from said collection region.9. The particle separation process of claim 8, wherein: said extraction occurs at the periphery of the fluidized bed.10. The particle separation process of claim 1, wherein said collection region surrounds said ad¬ jacent region, the process further comprising: extracting relative less dense particles from said fluidized bed at a location in an adjacent region displaced inwardly from said collection region.11. The particle separation process of claimI, wherein: the reaction surface containing the restricted area of communication comprises an annular wall . substan- tially surrounding at least a portion of said fluidized bed.12. The particle separation process of claimII, further comprising: extracting at least some of the more dense particles from said collection region at a vertical level approximating the top of the fluidized bed.13. The particle separation process of claim 11, wherein: said restricted area of communication comprises a relatively narrow vertical opening extending through said annular wall.14. The particle separation process of claim 11, wherein: said restricted area of communication comprises a narrow horizontally extending opening at a level be- neath the surface of the particle bed.15. The particle separation process of claim 1, wherein: said vertical reaction surfaces define a plu- rality of annular regions, each reaction surface between adjacent annular regions being provided with a limited area of communication for the movement of particles within the bed from one annular region to another.16. The particle separation process of claim 15, wherein: each limited area of communication is circum- ferentially displaced from the limited areas of communi¬ cation in adjacent vertical reaction surfaces.17. The particle separation process of claim 15, wherein: the radial dimensions of said adjacent annular regions progressively increases in the radial direction toward said collection region.18. The process of claim 1, wherein: the eccentric motion component of gyratory motion is so characterized that a net radial 'inward thrust is exerted thereby upon the particle mass, and said collection region is located radially inwardly of at least one adjacent annular region. 19. The particle separation process of claim1, wherein: the eccentric motion component of gyratory motion is so characterized that a net radially outward thrust is exerted thereby upon the particle mass, and said collection region is located radially outwardly of at least one adjacent annular region.20. The particle separation process of claim 1, wherein: the characteristic of gyratory motion and the dimensions of said reaction surfaces are such as to in- -35- duce a circular translational motion of the particle mass in at least one of said annular regions at a greater rate than in an adjacent region, and wherein particles are induced to move radially in said 5 fluidized bed from a region having a relatively low rate of circular particle motion to an adjacent annular region having a relatively high rate of circular motion, the particles of relatively greater density accumulating in said annular region having a relatively high rate of 0 circular motion.21- -The particle separation process of claim 3 11 1, wherein: said vertical reaction surface having said limited area of communication laterally confines the I fluidized bed in said adjacent annular region such that particles therewithin form a particle- column, said limi¬ ted area of communication being at a lower level of the bed, the process further comprising: extracting particles reaching a. given vertical 20 location in said column above said limited communication area.22. The particle separation process of claim 21, wherein: said confining vertical reaction surface is 25 dimensioned to induce a circular translational motion of the particles in said column.23. The particle separation process of claim 21, wherein: said column is disposed generally at the center 30 of gyratory motion and particles of selected relative density will migrate thereinto, while particles of dif¬ ferent relative density remain outside of said column.24. The particle separation process of claim 21, further comprising:35 providing a particle extraction passage in -36- said column leading from a first level vertically above the bed supporting surface downwardly to a second level below said bed supporting surface; and permitting at least certain of the particles reaching said first level to enter and thereby be ex¬ tracted from said bed through said extraction passage.25. The particle separation process of claim24, wherein: said extraction passage is disposed generally at the center of said particle column,26. The particle separation process of claim21, wherein: said area of communication comprises a gap between the bed supporting surface and the vertically extending surface.27. The particle separation process of claim1, wherein: the gyratory motion is of such, nature and the vertical reaction surfaces are so dimensioned as to in- duce a circular translational motion of the particles in the fluidized bed within said collection region, whereby particles of relatively greater density are caused to move in a circular translational path within said collection region. 28. The particle separation process of claim 7, further comprising: extracting said particles of relatively great- er density from the upper level of the fluidized bed in said collection region. 29. The particle separation process of claim lλ wherein the oscillatory vertical component of gyra¬ tory motion imparts to the particles of greater relative density an upward movement sufficient to enable them to accumulate at a level of the fluidized bed above the supporting surface. 30. The particle separation process of claim 29, further comprising: extracting said particles of greater relative density at the upper level of the fluidized bed. 31. The particle separation process of claim• 1, wherein the supporting surface is substantially im¬ pervious to the passage therethrough of particles to be separated.-32. The particle separation process of claim 1, wherein: the fluidized particle bed is substantially dry.33. The process of claim l. wherein: individual particles in said fluidized bed tend to spin in the direction of said circular motion; said reaction surface includes portions having projection components normal to the bed supporting sur¬ face, and the particles at the bottom of the bed con- tact said portions so as to react with said spin ten¬ dency to cause said circular motion of the particle mass.34. The process of claim 33, wherein: said surface portions comprise a plurality of concentric circular deformations normal to the plane of the supporting surface upon which the particle bed is disposed.35. A process for separating particles of selected density from an aggregated mass of classified particles having different densities, comprising the steps of: disposing the aggregated mass of particles upon a supporting surface to form a particle bed; agitating the supporting surface with a gyra- tory motion having a circularly eccentric motion com- -38- ponent and an oscillatory vertical component suffi¬ cient to fluidize the particle bed and thereby to sub¬ stantially reduce the resistance of 'the particle bed to translational movement of particles therewithin; contacting the particles in said fluidized bed with a plurality of vertical reaction surfaces moveable with the said supporting surface and defining (a) an innermost collection region and (b) at least one annular region surrounding said collection region, said supporting and reaction surfaces, in combination with said gyratory motion, having a surface area of frictional contact with said bed sufficient to impart to the particles a net circular and radially inward movement toward said collection region; providing restricted areas of communication between adjacent regions so as to permit particles of greater relative density in said fluidized bed to move through said restricted areas of communication, whereby particles of greater relative density move into and accumulate in said collection region and whereby particles of lesser relative density may be displaced from said collection region into the said surrounding region.36. The particle separation process of claim 35, further comprising: extracting particles of lesser relative den¬ sity from one of said surrounding annular regions.37. A process of separating particles of selected relative density from an aggregated mass of classified particles having different densities, com¬ prising the steps of: disposing the aggregated mass of particles upon a supporting surface to form a particle bed; agitating the supporting surface with a gyra- tory motion having a circularly eccentric motion co po-_0MPI - - nent and an oscillatory vertical component suffi¬ cient to fluidize said bed and thereby substantially reduce the resistance of the particle bed to transla-. tional movement of particles therewithin; 5 contacting the particles in said bed with•vertical reaction surfaces associated with the support¬ ing surface and defining a plurality of annular regions in said fluidized.bed, said supporting and reaction sur¬ faces, in combination with said gyratory motion, ener- 10 gizing the particles in said annular regions to cause particles of relatively greater density to move in paths having a net circular direction component and a net radial direction component; providing restricted areas of communication 15 between adjacent annular regions so as to permit par¬ ticles to move through said restricted areas from one annular region to an adjacent annular region; and • . permitting particles of greater relative den¬ sity to move in said paths of motion through said res- 20 tricted areas of communication into one of said regions for collection, while permitting particles of rela¬ tively less density to move into another of said annular regions.38, The particle separation process of claim 25 37, further comprising: adding particles to said fluidized bed in one annular region and extracting relatively less dense particles from a different annular region. 30 39. The process of claim 37, wherein: the particle bed is maintained at a height at least as great as said vertical reaction surfaces, there¬ by to enable relatively less dense particles to move from one annulat region to the next over the tops of 35 said vertical reaction surfaces. BURHΛ___O P_ - -40. The process of claim 39. wherein said particles of greater relative density move in paths having a net inward direction component, the collec¬ tion region being the innermost annular region, and relatively less dense particles are displaced out- 'wardly, at least some of said relatively less dense particles being displaced outwardly over the tops of said vertical reaction surfaces.41. A process for the separation of particles of selected density from an aggregated mass of classi¬ fied particles having different densities, comprising: disposing the aggregated mass of particles upon a supporting surface to form a particle bed; laterally confining the particles in the bed with vertical reaction surfaces so as to establish a plurality of annular channels for the fluidized par¬ ticles; providing restricted areas of communication between adjacent channels; agitating the supporting and reaction sur¬ faces with a gyratory motion having a circularly eccen¬ tric component and an oscillatory vertical component, said motion being such as to fluidize the particle bed and ^hereby reduce the resistance of the particle bed - to translational movement of the particles therewithin, and to induce a net radial and lateral movement within the annular channels of particles of selected density; and permitting said particles of selected rela- tive density to pass, through said restricted areas of communication by virtue of said radial and lateral move¬ ment so as to accumulate in a collecton zone defined by one of said channels.42. The particle separation process of claim 41 t wherein: - - said collection zone is disposed at the center of motion of the supporting surface, and the net radial movement of the particles of selected density is inward. 43. The particle separation process of claim 1, further comprising: extracting from one of said annular channels particles having a density predominantly different from the selected density. 44. The particle separation process of claim41, wherein: particles are extracted from an annular chan¬ nel separated from the collection zone by at least one intermediate annular channel. 45. The particle separation process of claim41, wherein: particles of selected relative density which accumulate in the collection, zone are those of greater relative density. 46. The particle separation process of claim41. wherein: the collection zone is constituted of the out¬ ermost annular channel and the net radial movement of particles of selected density is outward. 47. Apparatus for separating particles of selected relative density from an aggregate mass of classified particles having different densities, com¬ prising: means providing a surface for supporting the aggregated mass of particles constituting a particle bed; means supporting said surface means for at least limited lateral and vertical motion; means for agitating said supporting surface with a gyratory motion having a circularly eccentric motion component in an oscillatory vertical motion compo- -42- nent sufficient to fluidize the particle bed and thereby substantially reduce the resistance of the particle bed • to translational movement of relatively more dense par¬ ticles therewithin; reaction surface means associated with the supporting surface defining a plurality of annular chan¬ nels, said reaction surface means and supporting means providing an area of frictional contact with the par¬ ticle bed sufficient to energize the relatively more dense particles so as to cause them to move through the bed in paths having a net circular component and a net .radial component; said reaction surface means providing res- . tricted areas of communication between adjacent annular channels and being so configured to permit said rela¬ tively more dense particles to pass therethrough into an adjacent channel and there displace particles of relatively less density.48. The apparatus of claim 46, wherein: said supporting surface means includes por¬ tions of the supporting surface having projection com¬ ponents in planes normal to the plane thereof and dimen¬ sioned to contact the particles.49. The apparatus of claim 48, wherein: said surface portions comprise a plurality of concentric circular deformations normal to the plane of the supporting surface.50. The apparatus of claim 47, wherein: said supporting surface is substantially im- pervious to the passage of particles therethrough.51. The apparatus of claim 47, further com¬ prising: means for continuously extracting particles reaching a predetermined location in one of said adjacent annular channels. -43- 52. The apparatus of claim 47, wherein: said reaction surface means comprise a plu¬ rality of generally concentric rings extending upwardly from the particle-supporting surface, 53. The apparatus of claim 47,. herein: said restricted areas of communication are circumferentially displaced.54. The apparatus of claim 47, wherein the ^reaction surface means includes: - at least one particle-confining surface ex¬ tending upward from the supporting surface at the boun- • dary between adjacent annular channels to define a collection zone at a central region within said con- . fining surface and having an opening therethrough for ~ the movement of particles between regions interior and exterior thereof.55. The apparatus of claim 54, further com¬ prising: a second particle-confining surface radially 0 spaced from said first confining surface so as to define therewith an annular particle flow channel whereby particles of relatively greater density are free to move circularly and radially within said annular channel and through said opening into the collection zone. 5 56. The apparatus of claim 54, wherein: said opening defines a generally horizontal gap of narrow dimension located adjacent the supporting surface, whereby particles may move through such gap into the annular region bounded by the particle-confining sur- 0 face.57. The apparatus of claim 47, further com¬ prising: particle confining means extending upwardly from a level near the supporting surface in one of said 5 annular channels and having an opening to permit par-_^BU E ^ O -=: 3 03 P It Tt t→- to cr σ* rtP- TJ rt P» P« to ro t a ro O P ft o ro 3 P r J cu cu 3 P tr a TJ cn P» rt ro a P01 cn ro P- t→ Hi 3 cu ro< to P* 01 P t→ to ro CO ro P Hi P1 o O v u rt 01 Q P« o ro Hi o Hi z rt rt 3 3 r ro rt OP- ) TJ P P CO < a trP l→ T) P. rt CO Ui o to 3 ro rt¬ ro 3 to 3 o P« P- TJ ro OO a P* ro rt ro rt OH rt¬ rt CO 01 to t→ • Hi u to rt rt ro <! ro rt Tt t P* o fc! rt ro fc! a P> cr ro rt r to a rt P a Hi CO O 01 VJ ro a CO 0P H. rt¬ PJ o t→ OP fc! P» to 3 rt t fc_ •• P ro a a 3 Hi h- P toP a t→ u OP P« O P* tr -u P* rt VJ 01 0P ro to cu rt VJ a4 P*P« 3 cn cu 3 P« cr ro to o P rt rt S TJ ro N ro 3 O rt P« a o Hi a4 3* a rt o t→ a to ro P o £ a_ ro X Tl 3 r cu rt Z a σ4<i 01 vj01 Hi o P> P CO rt to cu VJ3 P' ro 3 tJ* rt ro . D4 to rt ro rt rt a OP a VJ CO ro O cu P. TJ trHi fc! rt 0P OP CD cu rt P* 3 ro to a o rt Hi fc! VJ rt rt rt o 0P ro P. rt Hi to a ro rt ro ro Hi OP P- o o rt OP rt OP P- rt01 rt o 3 Hi 3 rt tr P- P tr rt rt¬ Hi rt T) ro o P» %3 ro 3 ro ro to rt tr to rt a ro o o u rt 3 tr ro rt ro 01 3<J TJ to ro ro rt P* rt OP to . to 3 a to P* P a tr Hi tr σ4 rt TJ to rt OP 01 a P rt rt t→ rt to CO 0P ro rt¬ P* O Q P- ro P- rt ' CO P. rt Tl ro ro o rt ro ro to rt p 3CO a_ 3 aOP rtZ P1 P* o 3 OP rt P- u a4 rt oP« . ro P Hi 01 to to o Hi cr rt 01 P» P« rt¬ Ct rt rt 01 ro rt tr ro TJ rt ro P- O to trP- to P- p. σ o 3 P- t ro rt a r rt 3 a Hi Cu to a4 ro rt 01 3 to rt rt ro rt cu P« to o 03 a O rt ro tr •• • o 01 Hi to Tt P« OP01 ro P» rt 01 P« 3 ro P P*3 ro tr TJ Cu TJ a P* oTJ cr CD ro O to J p. ro a1 ro Hi rt ro u 1 rt O aPof communication by virtue of said radial movement so as to establish particle flow from one of said adjacent annular channels to the other.59. The process of claim 58, wherein said restricted area of communication is a gap defined be¬ tween the bottom portion of the intermediate reaction surface and the supporting surface.60. In an apparatus for separating par¬ ticles of selected relative density from an aggregate mass of classified particles having different densities, the combination of: means providing a surface for supporting the aggregated mass of particles constituting a par¬ ticle bed; means supporting said surface means for at least limited lateral and vertical motion; means for agitating said supporting sur¬ face with a gyratory motion having a circularly eccentric motion component in an oscillatory vertical motion component sufficient to fluidize the particle bed and thereby substantially reduce the resistance of the particle bed to translational movement of rela¬ tively more dense particles therewithin; reaction surface means associated with the supporting surface defining an annular region, said reaction surface means and supporting means pro¬ viding an area of frictional contact with the particle bed sufficient to energize the relatively more dense particles so as to cause them to move through the bed in paths having a net radial component; intermediate surface means defining with said reaction surface means at least two adjacent annular channels for fluidized particles, said inter¬ mediate surface. means being movable independently of said reaction surface means; and -46- said intermediate surface means defining a restricted area of communication between adjacent annular channels and being so configured to permit said relatively more dense particles to pass through the boundary defined thereby from one adjacent channel into the other.61. The apparatus of claim 58, wherein said restricted area of communication is a gap defined between the lower portion of said intermediate surface Q means and said supporting surface. | HAIGHT W | HAIGHT W |
WO-1979000323-A1 | 1,979,000,323 | WO | A1 | EN | 19,790,614 | 1,979 | 20,090,507 | new | C25B9 | C07D303 | C07D303, C25B3, C25B9 | C25B 3/02, C25B 9/06B, C25B 9/18 | ELECTROCHEMICAL CELL AND PROCESS | An electrochemical cell comprises a housing (1, 2) divided by a perforated generally horizontal plate (3) into an upper chamber (4) and a lower chamber (5). Bipolar electrodes (19, 21) are disposed in the upper chamber (4) above perforations (23) in the plate (3), between electrolyte inlet and outlet weirs (11, 13) for flowing electrolyte over the plate (3). The lower chamber (5) is a gas-supply chamber for passing a gas, e.g. propylene, up through the perforations (23), so as to bubble the gas through electrolyte (e.g. NaBr solutions) on the plate (3) and into the upper gas-collection chamber (4). A reactor may be formed by stacking several cells with their electrolyte flows in cascade. The cell is particularly suitable for electro-organic syntheses involving a gaseous reactant. | ELECTROCHEMICAL CELL AND PROCESSTechnical FieldThe invention relates to electrochemical cells r particularly for carrying out electrochemical reactions involving a gaseous reactant or in which gas is supplied for another purpose such as purging or sweeping away a product of reaction, or as a buffering agent or to inhibit unwanted reactions.The invention is more specifically, but not exclusively, concerned with an electrochemical cell for electro-organic synthesis, for example the electro¬ chemical oxidation of unsaturated and poly- nsaturated hydrocarbons, The electrochemical production of propylene oxide is particularly interesting, and will be discussed in greater detail by way of example.Background ArtIn the electrochemical production of propy¬ lene oxide, propylene is converted to propylene halohydrin by reaction with, halogen generated ±n situ by the anodic oxidation of _.he halide salt of an alkali metal in aqueous solution. The propylene halohydrin is converted to propylene oxide by reaction with the hydroxyl group at the cathode from which hydrogen is -liberated. The general'scheme of reaction when sodium bromide is used as the electrolyte is:Anode 2 Br . 3r, + 2 eC 3_.H,6_ + Br2. + H2_0 + HBr Cathode 2 H-0 f- H- + 2 OH- - 2e , C3H6BrOH + OH *- C3K_0 + H„0 + Br Overall C3-H6- + H20 —^ C3-H6.O + H2In principle, only water, propylene and electrical energy are consumed in the formation of propylene oxide and hydrogen. The halide electrolyte, sodium bromide, is continuously oxidized and re¬ generated within the cell for further use, although losses of bromine may be caused by the formation of hypobromite and bromine gas.- The advantages of this electrochemical route, which obviates the production of waste calcium chloride encountered in the conventional chemical process, have long been recognized but attempts to implement it have not proved to be very effective.French Patent Specification No. 1,375,973 and ~i. German Auslegeschrift No. 1,258,856 proposed the use of diaphragm cells in which propylene halohydrin is . generated at a porous anode and passes through the diaphragm into an alkaline catholyte in a porous cathode where it is saponified to propylene oxide. However, these cells are complex and the efficiency low.U.S. Patent Specification No. 3,394,059 proposed carrying out the halohydrin process in a non- divided cell, preferably a flowing mercury cathode cell, in which propylene was simply bubbled into the electro- lyte. Again, the performance was poor and F. Beck (IUPAC XXIVth International Congress, Hamburg, 1973, Vol.5, Applied Electrochemistry , pages 111-136) has claimed an improved performance using a capillary gap cell. In this, propylene dispersed in a dilute NaBr electrolyte is supplied through a central hole 5 in a pile of electrode discs and flows radially out¬ wards between the discs. The gap between the elec¬ trode discs was made small CO•2 to 0.5 mm), to enable * low bromide concentrations to be handled with low ohmic losses. A current efficiency of 70% or just Q above and an energy consumption of Q.23 - 0.30 kwh/ gmol propylene oxide are reported for a small capillary gap cell, but scaling up this cell for- industrial production would involve difficulties. Fleischmann et al, (.Symposium on Electro- 5 chemical Engineering _I, Newcastle 1971, Editor J.D. Thornton) have studied the synthesis of propylene oxide using a bipolar packed bed cell. The cell consisted of a packed bed made up of a mixture of conducting and non-conducting particles. The Q conducting particles become bipolar by using dilute electrolyte in the cell and applying sufficient voltage gradient between the contact electrodes so as to over¬ come the resistance drop in the electrolyte. Using glass coated with graphite as the conducting particles 5 and glass beads as the non-conducting particles, all particles having a diameter of about.0.05 cm, the energy consumption o .such a cell was found to be high, in the range of 2.5 - 3 kwh/gmol propylene oxide. A bipolar rod flow cell was used by King et al, 0 CTrans. Inst. Chem. Eng. , 53, 1975) for the production of propylene oxide. The cell consisted of vertical rows of electrically—conductive rods, separated from one another by a small gap. The electrolyte was fed to the top rods, flowed downvmrds over the vertical 5 rows and was collected from the bottom rods for re- gUR£_ £^ circulation. The gaseous reactant, propylene, was passed up the space between the vertical rows, in continuous contact with the electrolyte film. The current efficiency of this cell was of the order of 70% and the energy consumption is estimated in the range 0.35 - 0.4 kwh/gmol propylene oxide.R.E. . Jansson et al. have developed a bipolar electrochemical pump cell for which an energy yield below 0.2 kwh/gmol of propylene oxide is claimed (Journal of App. Electrochemistry, 7, (1977) , 437-443) for trial experiments on a laboratory scale using a cathode rotating at 3000 rpm with an electrode gap of 0.25 mm. However, the structure is not easily scaled-up for industrial production.Various other cell structures designed to provide a gas supply to the electrolyte are also known. For example, in the electrowinning of metals such as copper, it is well known to supply a gas through bubble tubes situated below the electrodes in order to agitate the electrolyte (e.g. see U.S. Patent Specification No. 3,875,041 and the earlier patents referred to therein). Another suggestion made in U.S. Patent Specification No. 3,259,049 was to provide electrolyte agitation in an electroplating tank using a hollow, flat manifold which is placed in the electrolyte, under the electrodes, and has a perforated upper surface for bubbling gas up into the electrolyte, the gas being supplied to the manifold via a gas flow tube. In contrast to the fixed bubble- tube arrangements, the entire manifold structure was made removable to facilitate periodic cleaning to remove fragments which may block the perforations in the manifold.Disclosure of InventionAn object of the invention is to provide anB 0 i\ AΓ> ORIGINAL electrochemical cell specifically (but not exclusively) for the production of propylene oxide and which can be designed to meet up. to the following requirements better than the previously proposed cells:1) Simplicity of the mechanical construction;2) Good heat and mass transfer characteristics;3) Simplicity of operation and continuous operation;4) ' Good gas-liquid contact; and5) Good mixing of anolyte and catholyte products.0 According to the invention, in its simplest form, an electrochemical cell comprises electrodes disposed over a perforated generally horizontal plate, an electrolyte inlet and an electrolyte outlet spaced apart on opposite sides of the electrodes across the 5 perforated plate, and a cell housing which is divided by the perforated plate into an upper chamber and a lower chamber. The lower chamber is a gas supply chamber from which, in use, gas passes up through perforations in the plate and bubbles through electro- Q lyte on the plate to collect in the upper chamber.The electrolyte inlet and electrolyte outlet of the cell are each advantageously formed by a weir. The top of the inlet weir is higher than the top of the outlet weir which in turn is higher than the top of the 5 electrodes. Hence, by controlling the supply of fresh electrolyte to the inlet weir, the electrolyte is made to flow over the inlet weir and between the electrodes as it passes across the perforated plate, while spent or reacted electrolyte flows out over the outlet weir at a 0 chosen rate.' These weirs may be formed by upstanding plates integral with or fixed on the perforated plate.The electrodes, advantageously a bipolar array of vertical plate-like electrodes 'disposed in spaced parallel relationship to provide channels between the ^-^ -^ y- electrolyte inlet and outlet,, may rest on the perforated plate which.,, in this instance, will be made of electric¬ ally insulating material. The perforations in the plate can be arranged in rows each spaced about mid-way between 5 adjacent electrodes. Perforations in the form of gen¬ erally circular bores having a diameter of about 1 mm hav been found satisfactory, but- perforations of other form and size can be used.The bottom of the lower chamber of the cell Q housing can serve as a receptacle for a pool of spent or reacted electrolyte which flows via a downcomer tube leading from the aforementioned outlet weir into the*pool from which electrolyte is removed via an outlet and may be recycled. Fresh electrolyte can be supplied to 5 the aforementioned inlet weir via an incomer tube which extends down through the upper chamber of the cell housi into the electrolyte retained by the inlet weir.The upper and lower chambers may be formed by upper and lower sections of a box-like cell housing, the 0 sections being separated by .the aforesaid plate which is perforated only in the region under the electrodes. A• rectangular enclosure for the electrodes may thus be formed by the side walls of the upper housing section fitting against upstanding plates forming the inlet and 5 outlet weirs. These side walls can carry inset termina electrodes of the electrode array.The invention also concerns an electrochemical reactor formed by stacking several cells according to th invention in a column whereby the gas-collection chamber Q of each cell (except the top one) forms the gas-supply chamber for the cell above. In other words, the per¬ forated plate of each cell (except the lowest one) forms the top of the gas-collection chamber of the cell below. With this arrangement, in operation, gas passes up 5 througb. the cells from the bottom of the column to the top, bubbling through the electrolyte in each cell. Preferably, the electrolyte outlets and inlets of the successive cells are connected in cascade so that the electrolyte 'flows down the column from one cell to the 5 next, the electrolyte flowing across the perforated plate of each cell from the inlet to the outlet and then down to the inlet of the cell below. Each cell of such a reactor can have the aforementioned preferred features of a single cell unit, such as the electrolyte Q inlets and outlets being formed By weirs.Another aspect of the invention is a method of carrying out an electrochemical process or reaction using a cell according to the invention, this method comprising passing gas up through the perforations in 5 the plate s o that it bubbles into the electrolyte on the plate. Depending on the reaction, the method may be operated continuously, i.e. continuously, supplying gas, electrolyte and electric current, or discontinuously, i.e. with an intermittent supply of gas, electrolyte and/ 0 or current.Yet another aspect of the invention is a method of carrying out an electrochemical process or reaction using a reactor formed by a column of cells according to the invention, this method comprising flowing 5 electrolyte down the column from. one cell to the next and across -the perforated plate of each cell, and passing gas up through the perforations in the successive plates so that the gas bubbles through the electrolyte on each plate. This method may also be operated continuously Q or discontinuously.The gas may be a reactant or a mixture of reac.ants, or may serve another purpose, for instance an inert purge gas such as nitrogen may be used to sweep away a product of reaction, or a buffering agent such as 5 CO- or .NH_ may be used to control the pH of the electro--Bϋkt^OΛ1PI lyte, for example to inhibit unwanted reactions.In addition to the preparation of propylene oxide, the cell according to the invention could be used in the electro-synthesis of other products such as the formation of butylene oxide from butene.Another important application is the electro¬ chemical treatment of some effluent gases. Generally speaking, many applications concern the situation where one or more of the reactants is a gas and where mixing of anolyte and catholyte is advantageous or inconsequen¬ tial.Brief Description of DrawingsEmbodiments of the invention are shown, by way of example, in the accompanying drawings, in which:Fig. 1 is a cross-section of a cell along the line I-I of Fig. 2;Fig. 2 is a cross-section along the line II-II of Fig. 1;Fig, 3 is a sectional view of the cell of Figs. 1 and 2 along the line III-III of Fig. 1;Fig. 4 is a cut-away view similar to Fig. 1, of part of a column formed of several cells connected in cascade.Best modes for carrying out the InventionThe cell of Figs. 1 to 3 comprises a generally rectangular box-like housing composed of an upper section 1 and a lower section 2. A plate 3, fixed between flanges 34 of the upper and lower sections 1,2 divides the housing into an upper chamber 4 and a lower chamber 5. The joints between the flanges 34 and the plate 3 are sealed by gaskets 6. The upper chamber 4 has an electrolyte inlet section 7, an electrode section 8 and an electrolyte outlet section 9. • The inlet section 7 comprises an incomer tube 10 which passes through the top 35 of the 5 upper section 1 and extends down to near the plate 3, between an upstanding plate 11 and three side walls 36 -of the section 1. The plate 11, which is integral with the plate 3, extends across the width of the chamber 4 and forms an inlet weir which, in use, holds a pool of10 electrolyte at a level 12, this electrolyte being del¬ ivered via the incomer tube 10.The electrolyte outlet section 9 comprises an outlet weir plate 13 which also extends across the width of the chamber 4, but is formed by one wall of an15 enlarged square end 14 of a downcomer tube 15 which passes through a hole 16 in the plate 3. The square end 14 is fitted in a corresponding square recess defined by the side walls 36 of the upper section 1 and an upstanding plate 17 integral with the plate 3. The20. top of the outlet, weir plate 13, is lower than the top of the inlet weir plate 11 and, in use, it maintains electrolyte in the electrode section 8 at a level 18.In the electrode section 8 are disposed seven electrodes 19 in .the form of plates held in spaced25 parallel relationship in vertical grooves 20 in the plates 11 and 17. The electrodes 19 are disposed between two terminal electrodes 21 which are inset in the side walls 36 through which pass current leads 22. The plate 11 at one end of the spaced electrodes, and30 the plates 17 and 13 at the other end define, with the side walls 36 of the section 1, an electrolyte receptacle whose' bottom is formed by a perforated central part of the plate 3. The perforations in the plate 3, indicated at 23, are in the form of circular holes or bores having 35 a diameter of about 1mm, arranged in eight rows each of -10-seven equally-spaced holes disposed mid-way between the adjacent electrodes 19 or 19 and 21.The upper, housing section 1 also comprises, in its top 35, a gas outlet pipe 24 for the removal of 5 gas from the upper chamber 4.In the lower chamber 5, the downcomer tube 15 extends near to the bottom, below the level of an upstanding wall 30 which forms a trap or weir holding a pool of outgoing electrolyte at a level 31. In the 0 bottom of the lower section 2 is an outlet pipe 32 for removing the electrolyte which has flowed over the weir wall 3Q. The lower housing section 2 also has a gas inlet pipe 33 for delivering gas into the lower chamber 5. Electrolyte in the bottom of the chamber 5 prevents this15 gas from escaping via the outlet pipe 32 or the down¬ comer tube 15, so that the gas passes up through the perforations 23 in the plate 3 and bubbles into the electrolyte between the electrodes 19, and 19 and 21 in the electrode section 8.20. To operate the cell, the electrolyte outlet pipe 32 is connected to the incomer tube 10 by an electrolyte circulating system, and the gas outlet pipe 24 is connected to the inlet pipe 33 by a gas circula¬ ting system. The electrolyte is circulated at a chosen25 rate so that fresh electrolyte from the incomer tube 10 flows over the inlet weir, namely the plate 11, across the electrode section _, i.e. through the parallel channe defined between the electrodes 19, and 19 and 21, and out over the outlet weir plate 13. The gas is also cir-30 culated at a chosen rate, which can be adjusted independently of the electrolyte flow rate. It passes from -the lower chamber 5 up through the perforations 23 and bubbles through the electrolyte between the electrodes 19, and 19 and 21 into the upper or gas-collection chambe 35 4. When all of the flows have been set up, current is supplied to the electrodes 13 and 21. In some instances, i.e. when the gas is a reactant, current is supplied to the electrodes as the gas is supplied, and the operation -is advantageously continuous, i.e. with constant electrolyte and gas flowrates. In other instances, however, it may be advantageous to operate discontinuously, i.e. with an intermittent flow of electrolyte or .gas or both, with- current supply during the appropriate phase.- The product of the electro- chemical reaction may be taken off as a gas and removed from the gas stream before recirculating, or may be : taken off dissolved in the electrolyte, in which case it is removed from the electrolyte before recycling. For the production of propylene oxide, the product will partition itself between the electrolyte and the gas phase and may therefore advantageously be removed through- -the σas outlet pipe 24 and separated by conden¬ sation .Industrial applicabilityA cell as shown in Figs. 1 to 3 was used for the production of propylene oxide. The electrodes were plates of graphite each 6.3 cm high, 8.3 __. long and0.3 cm thick 'and spaced apart by ' a distance cf about 4 ___.The electrolyte, 5 litres of 0.2M or 0.2K aBr solution, was flowed at a constant rate, in the range from about 20 3 to 45 cm /sec. Propylene gas was also circulated, using a supply of fresh propylene at. a constant rate in the3 range from about 5 to 40 cm /sec. Before supplying a constant current (.at from 1 to 2A and a constant voltage from 25 to 4QV) , the propylene was circulated for several minutes, to remove air from the cell housing and to saturate the electrolyte solution. Operation was carried out at ambient temperature and atmospheric,. pressure and the pH of the electrolyte was maintained between about 11. and 12 by ^_V ^ adding HBr solution. Gas and liquid samples were checked at 1/2 hourly intervals. In some instances, a foaming agent (. Decon , Trademark) was added with a view to promoting rapid mass transport of the reactants to the electrodes, and to increase the solubility of propylene. The results showed a high current efficien about 80.%, and a low energy consumption, 0.2 to 0.3 kwh/gmol of propylene .oxide when operating at low temperature, low current and low gas flowrate using dilute NaBr. For the epoxidation of 1-butεne using th same cell, an energy consumption of 0.26 kwh/gmol of butylene oxide was achieved at a current efficiency approaching that obtained with propylene oxide. These performances may be improved by optimizing the cell dimensions and process conditions and, possibly, by operating at elevated pressures.As shown in Fig. 4, several cells similar to that of Figs. 1 to 3 can be stacked in a column with the electrolyte flow system connected in cascade. In Fig. 4, the same parts are designated by the same references as before, some parts of the intermediate cells -being designated by double references. The upper section 1 of the housing of the top cell and the lower section 2 of the housing of the bottom cell are exactly the same as the upper and lower sections 1 and 2 of Figs. 1 and 2. However, in the reactor column, the perforated plate 3 forming the bottom of one cell also forms the top of the gas collection chamber 4 of the cell below and its perforations 23 act as the gas outlet for that chamber; the downcomer tube 15 for the discharge of electrolyte from one cell forms the incomer tube 10 of the cell below; the gas collection chamber 4 of eac cell (except the top one), forms the gas supply chamber 5 for the cell above; and so- forth. In operation of this reactor column, gas is supplied at the bottom of the column, via the inlet pipe 33, passes up through the successive cells, bubbling up through the electrolyte in each electrode section 8, and is removed from the top of the column via the outlet pipe 24. Electrolyte is supplied at the top 35 of the column via the top incomer tube 10 and, as indicated by the arrow, cascades down from one cell to the next, flowing across the electrode section 8 of each cell, and is removed from the bottom of the column via the outlet pipe 32. As before, current is supplied to the electrodes of each cell and the operation may be continuous or discontinuous.Many variations may be made to the described embodiments. Various electrode materials can be used, depending on the reaction: ..in particular, dimen- sionally-stable metal electrodes will be preferred for some reactions. Also, the electrodes need not be bipolar. In some instances, spaced parallel electrodes can be disposed transverse to the general direction of flow of electrolyte across the perforated plate.Various shapes and sizes of perforations can be provided in this plate and, instead of being disposed between the adjacent electrodes, for certain reactions these per¬ forations could lead into porous or foraminous electrodes disposed on the perforated plate. Instead of the preferred electrolyte inlet and outlet weirs, other means could be provided to enable a flow of the electrolyte generally across the perforated.plate, while maintaining a given electrolyte level.OΛ.PI | CLAIMS1. An electrochemical cell, comprising electrodes disposed over a perforated generally hori¬ zontal plate, an electrolyte inlet and an electrolyte outlet spaced apart on opposite sides of the electrodes across the perforated plate, and a cell housing which is divided by the perforated plate into an upper chamber and a lower chamber, wherein the lower chamber is a gas supply chamber for passing gas via the perforations in the perforated plate through the electrolyte located above the plate in the upper chamber.2. The electrochemical cell of Claim 1, wherein the electrolyte inlet and the electrolyte outlet are each- formed by a weir, 3. The electrochemical cell of Claim 2, wherein the top of the electrolyte inlet weir is higher than the top of the electrolyte outlet weir which is higher than the top of the electrodes.4. The electrochemical cell of Claim 2 or 3, wherein the weirs are formed by plates upstanding from the perforated plate.5. The electrochemical cell of claim 1, comprising a bipolar array of vertical plate-like electrodes disposed in spaced parallel relationship to define channels between the electrolyte inlet and the electrolyte outlet.6. The electrochemical cell of claim 5, wherein the bipolar electrodes rest on the perforated plate, which is made of electrically-insulating material, and wherein the perforations in the plate are arranged in rows spaced about mid-way between adjacent electrodes.7. The electrochemical cell of claim 2, wherein a bottom part of the lower chamber forms a receptacle for a pool of reacted electrolyte, and a downcomer tube leads from the electrolyte outlet weir-~_ _} R EO to the bottom part of the lower chamber, for the delivery of reacted electrolyte to the pool.8. The electrochemical cell of claim 7, comprising an incomer tube extending down through the upper chamber, for the delivery of fresh electrolyte to the electrolyte inlet weir.9. The electrochemical cell of claim 1, wherein the upper and lower chambers are formed by respective separate upper and lower sections of a box-like cell housing, the housing sections are separated by and secured to the periphery of the plate and the per¬ forations are disposed in the plate only in the region under the electrodes.10. The electrochemical cell of claim 9, wherein the.upper housing section has facing side walls which fit against upstanding plates forming electrolyte inlet and outlet weirs to define a rectangular enclosure for the electrodes.11. The electrochemical cell of claim 10, comprising a bipolar array of vertical plate-like electrodes disposed in spaced parallel relationship to define channels between the electrolyte inlet and electrolyte outlet weirs, said electrode array including terminal electrodes inset in said facing side walls of the upper housing section.12. An electrochemical cell, comprising: a cell housing; a perforated generally horizontal plate dividing the cell housing into an upper chamber and a lower chamber; electrodes disposed in the upper chamber ~ over perforations in the perforated plate; and means defining an electrolyte inlet and an electrolyte outlet spaced apart on opposite sides of the electrodes across'_ _T EA7 the perforated plate to maintain electrolyte on the perforated plate at an intermediate level of the upper chamber so as at least partially to immerse the electrodes and define a gas-collection space in the upper chamber above the electrolyte; the lower housing chamber constituting a gas supply chamber for passing gas up through perforations in the plate so as to bubble the gas through the electrolyte on the plate and into the gas-collection space13. An electrochemical reactor comprising (I) a plurality of cells, each cell comprising (i) electrodes disposed over a perforated generally horizontal plate and (ii) an electrolyte inlet and (iii) an electrolyte outlet spaced apart on opposite sides of the electrodes across t perforated plate, and (.II) a reactor housing in which the cells are stacked in a columnar arrangement, the perfora- ted plates of the cells dividing the reactor housing into superimposed chambers, each perforated plate being dis¬ posed over a gas-supply chamber for passing gas up throug perforations in the plate to bubble through electrolyte on the plate and collect in the chamber thereabove and which (.except for that of the top cell) forms the gas- supply chamber for the cell above.14. The electrochemical reactor of claim 13, wherein the electrolyte inlet and the electrolyte outlet of each cell are formed by weirs. 15. The electrochemical reactor of claim 14, wherein the top of the electrolyte inlet weir of each cell -is higher than the top of the electrolyte outlet weir which is higher than the top of the electrodes. 26, The electrochemical reactor of claim 14 or 15, wherein the weirs are formed by plates upstanding from the perforated plates,17. The electrochemical reactor of claim 13, wherein each cell comprises a bipolar array of vertical plate-like electrodes disposed in spaced parallel relationship to define channels between the electrolyte inlet and the electrolyte outlet of the cell.18. The electrochemical reactor of claim 17, wherein the electrodes rest on the perforated plate of the associated cell, each plate is made of electrically- insulating material and the perforations in each plate are arranged in rows spaced about mid-way between the respective adjacent electrodes.19. The electrochemical reactor of claim 14, comprising downcomer tubes for delivering electrolyte from the electrolyte outlet weir of each cell (.except the lowest one) to the electrolyte inlet weir of the cell below.20. The electrochemical reactor of claim 19, wherein a bottom part of the lowest chamber forms a receptacle for a pool of reacted electrolyte and a further downcomer tube leads from the electrolyte outlet of the lowest cell to the bottom part of the lowest chamber, for the delivery of reacted electrolyte to the pool. 21. The electrochemical reactor of claim 2Q, comprising an incomer tube extending down through the top chamber, for the delivery of fresh electrolyte to the electrolyte inlet weir of the top cell.22. The electrochemical reactor of claim 13, wherein the respective sections of the reactor housing are separated by and secured to the periphery of the respective horizontal plates, which are perforated only in the regions under the electrodes of the respective cells of the reactor. 23. The electrochemical reactor of claim 22, wherein each housing section Cexcept the lowest one) has facing side walls which fit against upstanding plate forming electrolyte inlet and outlet weirs to define a rectangular enclosure for the electrodes of the respecti cell.24. The electrochemical reactor of claim 23,- wherein each cell comprises a bipolar array of vertical plate-like electrodes disposed in spaced parallel rela¬ tionship to define channels between the electrolyte inle and outlet weirs of the cell, each electrode array including terminal electrodes inset in the facing side walls of the respective housing section.25. An electrochemical reactor comprising: . a reactor housing; a plurality of mutually-spaced perforated generally horizontal plates disposed in superimposed relationship to divide the reactor housing into superimposed chambers; electrodes disposed in each chamber (.except the lowest one) over perforations in the respective plate; means defining an electrolyte inlet and an electrolyte outlet spaced apart on opposite sides of the electrodes across each perforated plate to maintain elec¬ trolyte on the perforated plate at an intermediate level of the respective chamb so as at least partially to immerse the respective electrodes and define a gas- ' collection space in the chamber above the electrolyte; each chamber (except the top one) con¬ stituting a gas-supply chamber for passing ga up through perforations in perforated plat at the top of the chamber to bubble the ga through the electrolyte on the plate and into the gas-collection space in the chamber thereabove and which (except for that of the top cell) forms the gas- supply chamber for the cell above; - and means connecting the electrolyte outlets and inlets of successive cells in cascade to flow electrolyte down the reactor from the electrolyte outlet of one cell to the electrolyte inlet of the cell below.26. A method of carrying out an electrochemical process or reaction in an electrochemical cell comprising electrodes disposed over a perforated generally hori- zontal plate, an electrolyte inlet and an electrolyte outlet spaced apart on opposite sides of the electrodes across the perforated plate, and a cell housing which is divided by the perforated plate into an upper chamber and a lower gas-supply chamber, the method comprising passing gas from the gas-supply chamber up through per¬ forations in the plate to bubble through electrolyte on the plate and collect in the upper chamber.27. A method of carrying out an electro¬ chemical process or reaction in an electrochemical reac- tor comprising (I) a plurality of cells, each cell comprising (_i) electrodes disposed over a perforated generally horizontal plate and (.ϋ) an electrolyte inlet and (iii) an electrolyte outlet spaced apart on opposite sides of the electrodes across the perforated plate, and (II) a reactor housing in which the cells are stacked in a columnar arrangement, the perforated plates dividing the reactor-housing into superimposed chambers, each perforated plate being disposed over a gas-supply chamber for passing gas up through perforations in the plate to bubble through electrolyte on -the plate and collect in the chamber thereabove and which (except for that of the top cell) forms the gas-supply chamber for the cell above, the method comprising flowing electrolyte down the columnar reactor from one cell to the next and across the perforated plate of each cell, and passing gas up through the perforations in the successive plates so that the gas bubbles through the electrolyte on each plate.28. The method of claim 26 or 27, wherein the gas is a reactant in the electrochemical reaction.29. The method of claim 26 or 27, wherein the gas is propylene and the electrolyte is a halide salt of an alkali metal in aqueous solution. | GOODRIDGE F; PLIMLEY R | GOODRIDGE F; PLIMLEY R |
WO-1979000325-A1 | 1,979,000,325 | WO | A1 | XX | 19,790,614 | 1,979 | 20,090,507 | new | G01V1 | null | G01V1 | G01V 1/133 | SEISMIC SOURCE FOR USE UNDER WATER | A seismic source (10) is described which drives one or more jets of high velocity water into an underwater environment and then abruptly terminates the jets. The momentum of the free jet columns generate vapor cavities in the water away from the housing (12) of the source which cavities collapse coherently to generate the seismic signal. A piston (22) and a valve sleeve (38) are slidably mounted in a cylinder (14) in the housing. The piston seals off a volume of gas on its rearward side. The forward side of the piston defines one surface of a chamber (24). The chamber receives high pressure water from an inlet. In its rearward position the valve sleeve seals a set of jet apertures (60) in the side of the cylinder. In its forward position the valve sleeve opens the apertures, exposing the chamber interior to the exterior underwater environment. With the valve sleeve in its rearward position with the apertures sealed, the high pressure water entering the chamber (24) moves the piston to its rearward position and compresses the gas. The sleeve (38) is hydraulically actuated upon command to abruptly open the jet apertures, enabling the piston to move forwardly under the pressure of the compressed gas, driving the water through the jet apertures so as to form the jets. The piston (22) enters the interior (40) of the sleeve (38) near the forward end of its stroke and, concurrently, abruptly terminates the jets. To re-arm the source, the sleeve is actuated to close the jet openings whereupon the high pressure water resets the piston (22). Upon the next command, the valve sleeve (38) is again actuated to open the apertures and the next seismic signal is generated. | DescriptionSeismic Source for Use Under WaterThe present invention relates to seismic sources and particularly to a seismic source of the type which generates seismic signals by means of the collapse of vapor cavities formed when a free jet column of water is launched into an underwater environment.The invention is especially suitable for use in providing an improved seismic source of the so-called water-gun type wherein a high velocity water jet is abruptly terminated, as it leaves the housing of the source, to generate a cavity or void away from the housing which cavity collapses to produce a pressure transient, providing a seismic signal. Water gun seismic sources which have heretofore been used require an air compressor which supplies compressed air to a fast-acting valve. When the valve is released, the compressed air is applied to drive a piston which forces water through a nozzle for developing the jet. The compressed air also cocks or resets the piston of the gun. The charge of compressed air for firing the gun is lost each cycle, leading to inefficient operation and long cycle times (i.e., low firing rates), for example, one shot every eight seconds for a large gun. In addition, the nozzle which forms the jet is located along the axis of the piston, the jet must be deviated by 90° into a number of secondary jets in order to minimize the recoil of the gun on firing. The deviation process leads to further inefficiencies in operation, -for example due to turbulent flow in the secondary jets. It is an object of the present invention to provide an improved seismic source of the type which develops one or more free jet columns of water in order to generate a seismic signal in which the fore- going disadvantages are obviated.It is a further object of the invention to provide an improved seismic source of the water gun type which is actuated by high pressure water rather than by compressed air as the energy source and thus provides higher operating efficiency than water gun sources which have heretofore been suggested.It is a still further object of the present invention to provide an improved seismic source of the water gun type which can provide opposed jets for recoil elimination without the need for jet deviation, thus affording more efficient operation than water gun type sources heretofore proposed. It is a still further object of the present invention to provide an improved seismic source of the water gun type which is precisely controllable in time of firing and may be used in arrays contain¬ ing a multiplicity of sources which can be operated simultaneously or in precise time sequence.Briefly described, a seismic signal source provided by the invention for use under water contains a housing having a cylinder. A piston is εlidably disposed in the cylinder for travel in forward and rearward directions and divides the cylinder into first and second chambers on the forward and rearward sides of the piston. The second chamber has a gas trapped therein which is compressed when the piston travels in the rearward- direction. High pressure water is supplied to the first chamber. A water jet forming aperture extends through the housing into the first chamber. This aperture may be one of a pair of apertures which are di_ aSm.etrically opposite each other. A valve member is slidably disposed in the first chamber in porting relationship with the jet aperture for opening the aperture to enable the pis- ton to travel under the force of the compressed gas in the forward direction to drive a jet of water through the aperture. No jet deviation is involved since the jet is developed in an aperture whose axis • is already at 90° to the direction of travel of the piston. The piston is also disposed in porting relationship with the jet aperture for closing the aperture, after the opening thereof by the valve member, to terminate the jet and generate a vapor cavity in the water outside the housing. The collapse of this cavity produces the seismic signal. To this end the* alve member may be a sleeve which receives the piston in sealing relationship such that the aperture is closed as the forward edge of the piston enters the sleeve. The valve member is actua- ted to close the jet aperture after the jet is termi¬ nated. This enables the pressurized water in the first chamber to drive the piston in the rearward direction thereby resetting the source. Upon command the valve is actuated to open the aperture and the next seismic signal is then generated.The foregoing and other objects and advantages of the invention as well as a presently preferred embodiment thereof will be more apparent from a reading of the following descriptions in connection with the accompanying drawings in which:PIGS. 1 through -4 are sectional views of a seismic source embodying the invention each showing the source in a different position during the cycle of operation thereof and FIG. 5 is a sectional view of the source shown in -FIGS. 1 through 4; the section being taken along the line 5-5 in FIG. 1.Referring more particularly to the drawings, the water gun 10 has a cylindrical housing 12 having a bore which forms a closed cylinder 11. The cylinder has regions of different diameter which forms steps 16 and 18. A cylindrical groove 20 is located in the inner wall of the cylinder 14 below the step 18. The step 18 is tapered in part and in part forms a li .A piston 22 is slidably disposed in the cylinder 14 and divides the cylinder into a first chamber 24 and a second chamber 26 on the forward and rearward sides thereof respectively. The outer wall of the piston has an inward taper 28 at the forward end 30 thereof. A 0 ring 32 seals the first chamber 24 from the second chamber 26. The rearward end of the piston has a large blind opening 34 therein for purposes of lightening the piston's weight. The step 16 serves as a stop for the travel of the piston in the rearward direction. A cylindrical stub 36 which extends upwardly from the bottom of the housing serves as a stop for the piston travel in the forward direction. A valve member 38 in the form of a cylindrical sleeve is slidably disposed in the first chamber 24 'and fits into the groove 20. The opening 40 in the sleeve valve member 38 is of the same diameter as the piston. The rearward portion 42 of the sleeve 38 is of larger diameter than the forward portion 44 there¬ of and forms a step 46. The outer diameter of the portion 42 has a sliding fit in the groove 20 and a seal is provided by an 0 ring 48. The forward portion 44 has a sliding fit with the cylinder 14 and a seal is provided by another 0 ring 50. A-BU EΛTΓOΛ.PI control chamber 52 is formed in the groove 20 between the wall of the housing 12 and the step 46 and outer diameter of the lower portion 44 of the valve sleeve member 38.5 Electrohydraulic control means for the source which operate to actuate the valve sleeve member 38 Is provided by an electrohydraulic valve 54. This valve may include a spool which Is moved by a solenoid 56 operated by electrical command signals10 applied thereto. The valve 54 switches pressurized hydraulic fluid between high and low pressures Indicated as Ps and PR into the control chamber 52. This fluid is preferably water and may be supplied from a pump. The pressure Pg is higher than the15 pressure of the ambient water at the depth of operation. A suitable pressure is 2000 Pg. The high pressure side provides the fluid at the supply pressure P _<_-> while th*e low pressure side or return pressure is PR. The return pressure may also come 20 from a reservoir which is connected to the return side of the pump.High pressure water, preferably at the same pressure Pg and suitably supplied from the same pump is continuously applied to the first chamber 24. A 25 conduit through the bottom of the housing 12 which extends through the stop 36 provides access for the high pressure fluid to the first chamber 24. The ~~ upper end of the stop 36 has a notch 58 to prevent the sealing off of the high pressure water supply 30 to the chamber 24 when the forward end 30 of the . piston moves up against the stop 36.Compressed gas, suitably air, is supplied to the second chamber 26. Preferably the chamber 26 is sealed as by a stop cock after being filled with 35 compressed air to the desired pressure. As will become more apparent as the description proceeds the compressed air is used only as an energy storage means. It may be noted that for deep water .operation the chamber 26 may be sealed at the surface. This will provide sufficient air pressure in the chamber 26 for energy storage and for developing compressed air forces on the piston when the source is fired. The energy for cocking the piston (viz, resetting it in the position against the stop 16 as shown in FIG.l) Is supplied hydraulically by the high pressure water at Pc. The high velocity jets are formed In apertures 60. These apertures are disposed at 90° to the direction of movement of the piston 22 (viz, perpendicularly to the axis of the cylinder 14). There are no apertures or nozzles to form the jet within the cylinder. The jet is formed at 90° to the direction of piston travel and jet deviation by 90° is not necessary. - The jet apertures 60 are disposed in pairs, two pairs being shown. The apertures are diametrically opposite to each other and the pairs of apertures are disposed with their axes in the same plane which is perpendicular to the axis of piston travel. The aperture 60 may be circular in cross section and typically may have areas in total of one- fourth to one-tenth that of the area of the forward end 30 of the piston 22. The major portion of the kinetic energy that is developed by the source 10 is in the jets, while only a small portion is associated with the motion of the piston 22. The configuration of -the source 10 provides for the generation of jet columns of desirably long lengths, since the forward stroke of the piston to the position where the jets are terminated may be made long. For example, the piston travel from the reset position shown in FIG.l to the jet orifices 60 may be several times the diameter of the piston. FIG. 1 shows the source armed for firing. The control valve 5 is not actuated (viz, the solenoid 56 has not received a command signal and is not pulled in). The spring 62 thus positions the valve so that water at supply pressure P„ is applied to the cavity 52. The valve member 38 is In Its rearward position with its rear end (the upper end as shown in the drawing) butted against the 'sealing lip 18 of the housing 12. Consider that the area of the upper end of the sleeve valve member 38 is about twice the area t_ of the lower end thereof within the cavity 24 and about twice the area of the step 46. Consider also a linear pressure drop across the sealing lip 18 when the valve is closed. Then the force due to the pressure on the lower end of the valve member and on the step 46 tending to close the valve is almost twice the force on the upper end of the valve member 38 tending to open the valve. The valve covers the jet orifices 60 and these orifices remain close until the valve 38 is actuated, upon command, in the forward direction. Prior.to such actuation, pressu¬ rized water has forced the piston 22 back against the stop 16 and the gas behind the piston in the chamber 26 is compressed. When a command signal is applied to the solenoid the valve 54 Is abruptly shifted to the position shown In FIG. 2. The pressure In the control cavity 52 then drops to PR. Even with a linear pressure drop across the sealing lip 18, large net forces in the forward direction are developed on the valve member 38 and It moves abruptly In the forward direc¬ tion (viz, downwardly) to the position shown in FIG. . The jet apertures 62 are opened. The piston accele¬ rates in the forward direction applying, approximately, the pressure of the compressed gas in the chamber 26 through the piston 22 to the water in the chamber 24. The water is driven through the jets and forms high velocity jet columns in the marine environment surrounding the housing 12. When the forward end 30 of the piston passes the jet apertures 60 and enters the opening 40 in the sleeve valve member 38 (see FIG. 3) the apertures 60 are abruptly closed due to the portingrelationship therewith of the piston 22. The jets are abruptly terminated, and free jet columns are launched into the water surrounding the housing 12. A set of vapor cavities is generated exterior to the outside wall of the housing 12. The coherent collapse of these cavities forms the pressure transient which provides the seismic signal.The taper 28 on the front edge of the piston is provided for controlling the deceleration of the piston as it enters the opening 4θ in the valve sleeve member 38. Accordingly, the deceleration is controlled and high pressures Inside the housing 12 are avoided. Since the piston 22 upon entering the valve sleeve opening 40 tends to seal off the region between the exterior walls of the piston which includes the apertures 60, the pressure on the upper end of the valve sleeve member 38 Is decreased below P„ enabling the valve to again close the aperture 60. Also the regions bounded by the apertures, the piston, the larger upper end of the valve member 38 and the portions of the housing 12 opposite to that upper end are at the pressure of the ambient sea water which is less than Pg. When Pg is applied to the step 46, the valve member 38 is easily actuated upwardly to effect such closure.As shown In FIG. 4, the valve 4 is permitted to return to Its initial position (viz, the solenoid 56'BU £ s is de-energized) . The pressure in the control chamber 52 returns to P-. Both the valve 38 and the piston 22 move rearwardl . The valve stops when its upper end butts against the sealing lip lδ. The piston travels along its return stroke until it reaches the step 16. The source is then armed and ready for firing to produce the next signal when the next command is applied to the solenoid 56 of the control valve 54. From the foregoing description it will be apparent that there has been provided an improved seismic source. By means of hydraulic actuation and control considerable efficiencies are obtained and rapid firing is made possible. Variations and odifi- cations in the herein described source will undoubt¬ edly suggest themselves to those skilled in the art. Accordingly, the foregoing description should be taken merely as illustrative and not in any limiting sense. | Claims1. A seismic signal source for use under water which comprises(a) a housing having a cylinder,(b) a piston slidably disposed in said cylin- der for travel in opposite directions and dividing said cylinder Into first and second chambers on opposite sides of said piston,(c) said second chamber having a gas trapped therein which is compressed when said piston travels in one of said directions,(d) means for supplying pressurized water to said first chamber,(e) a water jet forming aperture extending through said housing into said first chamber, (f) a valve member slidably disposed in said first chamber in porting relationship with said jet aperture for opening said aperture to enable said piston to travel under the force of said compressed gas in the other of said directions to drive a jet of water through said aperture, (g) said piston also being disposed in porting relationship with said jet aperture for closing said aperture after the opening thereof by said valve member to terminate said jet and generate a vapor.cavity in the water outside said housing, the collapse of which produces the seismic signal, and(h) means for actuating said valve member to -close said jet aperture after said jet is termi- nated to enable the pressurized water in said first chamber to drive said piston In said one direction to reset said source and for opening said aperture when the next seismic signal is to be generated. 2. The invention as set forth in Claim 1 wherein the axis of said jet aperture is disposed at about 90° to said direction of travel of said piston.3. The Invention as set forth In Claim 2 wherein at least a pair of said apertures are provided which are disposed diametrically opposite to each other.4. The invention as set forth in Claim 3 wherein said apertures are circular ports in the wall of said housing.5. The invention as set forth in Claim 1 wherein said valve member is movable in opposite directions over a stroke which is substantially smaller than the travel of said piston.6. The Invention as set forth in Claim 1 wherein said valve actuating means comprises fluid pressure operated means for developing hydraulic forces to move said valve member In said opposite directions, and electrohydraulic control means for controlling said fluid pressure means in response to command signals.7. The invention as set forth in Claim 6 wherein said fluid pressure operated means comprises a control chamber defined by said valve member and the wall of said cylinder on which said valve member is slidably disposed, said valve member presenting to said control chamber a first surface area In a plane normal to the direction of movement of said valve member on which'BυREΛ pressurlzed fluid forces are developed for moving said valve member, and said electrohy¬ draulic means comprising a valve for selec¬ tively applying pressurized hydraulic fluid at ' a higher and a lower pressure to said control chamber.8. The invention as set forth in Claim 7 wherein said higher pressure Is the same as the pressure of the water supplied to said first chamber, and said valve member having at opposite ends thereof In said first chamber surface areas In planes normal to the direction of movement of said valve member, one of which is larger than the other.9. The invention as set forth in Claim 8 wherein the larger end of said valve member is disposed adjacent to said jet aperture and Is disposed in overlapping relationship with said piston when said piston closes said jet aperture so as to define a region within said housing bounded by said aperture, said piston, said larger end of said valve member and the portion of said housing opposite to said larger end of said valve member, which region is at the pressure of the water surrounding said housing.10. The Invention as set forth in Claim 1 wherein said valve is a sleeve the outer wall of which is disposed In sliding relationship with said housing and the inner wall of which defines an opening which receives said piston with the outer wall thereof in sealing relationship with said inner wall when said piston travels In said other direction to close said aperture and terminate said jet. 11. The invention as set forth in Claim 10 wherein the cross sectional area of said cylinder and the circumferential opening defined by the rear end of said sleeve and the sealing lip of said cylinder when said valve is in its forward position is much larger than the cross section area of said aperture such that said jet of water is formed in said aperture.12. The invention as set forth in Claim 11 including means in said housing for limiting the travel of said piston in said one direction away from said valve member and in the opposite direction toward and into said valve member, said jet aperture being disposed between said limiting means such that the distance over which said piston travels to the position where it closes said aperture is at least about the diameter of said piston.13. The invention as set forth in Claim 10 wherein said housing has a groove in the inner wail thereof, said sleeve having an upper end of larger outer diameter than the lower end thereof, said upper end being disposed in said groove and defining a control chamber therein, said aperture extending into said groove above said control chamber, the- upper end of said groove defining a sealing lip which closes said aperture when said sleeve moves upwardly, and said valve member actuating means comprising means for applying pressurized fluid select¬ ively at supply and return pressures to said control chamber such that the net forces on said sleeve are in an upward direction or in a downward direction.-βUREΛϋ OMPI 14. The invention as set forth in Claim 13 wherein the area of the upper end of said sleeve In a plane normal to the direction of travel of said valve is about twice that of the lower end of said sleeve,the area In a plane normal to the direction of movement of said sleeve presented by said sleeve to said control chamber is about half said area of the upper end of said sleeve, and said pressure supplied to said first chamber and said supply pressure are about equal to each other. | HYDROACOUSTIC INC; HYDROACOUSTICS INC | BOUYOUCOS J |
WO-1979000326-A1 | 1,979,000,326 | WO | A1 | XX | 19,790,614 | 1,979 | 20,090,507 | new | A61F1 | A61F9, A61B17, A61F1 | A61F2 | A61F 2/16B, A61F 2/16C, K61F 2/00L2 | COATED INTRAOCULAR LENS AND THE LIKE | An intraocular lens or surgical tool used for eye surgery which is covered with a water-soluble adherent film coating (8, 17 and 18) that has a very slow dissolution rate which maintains at least 40% of the coating on the lens for at least 30 minutes, but not more than 24 hours, when submerged in an aqueous media simulating the surgical environment. Polyvinyl alcohol is an example of such coating that is dissolvable in water and provides swellable outer portions of the coating that are sluffable so as to be self-sacrificing in protecting against both static and sliding contact with a corneal endothelium. | DescriptionCoated Intraocular Lens and the LikeTechnical FieldThis invention relates to a specially coated intraocular lens that helps prevent damage to the corneal endothelium during surgical implantation.When the natural lens of the human eye becomes physically damaged or has some disease necessitating its removal, such as a cataract, it is often replaced with an artificial intraocular lens.During the process of surgically implanting such lens through an incision at the edge of the cornea, it has been found that static touching of the corneal endothelium with a polymethylmethacrylate (PMMA) lens or surgical tool, can permanently destroy a portion of the endothelial cells. It is generally recognized that the human endothelium, which is only one cell layer thick, cannot regenerate itself by producing additional cells. It appears that more damage is done to the corneal endothelium by a dynamic or sliding contact with such lens or tool during surgery as compared to a static or nonsliding contact with the endothelium. The corneal endothelium is very critical to the eye as it is a barrier between the outer layers of the cornea and the aqueous humor in the anterior chamber. After surgery, the location of the intraocular lens is such that, when in its proper position, it does not contact or damage the corneal endothelium.Background ArtIt has been suggested by others to coat the intraocular lens with methylcellulose (MC) or polyvinyl- pyrrolidone (PVP) . The following publications describe such coating.Kaufman, H.E. and J.I. Katz, Endothelial Damage From Intraocular Lens Insertion, Inv. Ophth. , Vol. 15(12), Dec. 1976, p. 996-1000Kaufman, H.E. , Jeffrey Katz, et al, Prevention of Endothelial Damage From Intraocular Lens Insertion, Tr. Am. Acad. Ophth. & Otol. , Vol. 83, Mar-Apr. 1977, p. 204-212Kaufman, H.E. and J.I. Katz, Pathology of the Corneal Endothelium, Inv. Ophth. Visual Sci., Vol. 16(4), April 1977, p. 265-268Fechner, P.U., Methylcellulose In Lens Implanta¬ tion, Jour. Amer. Intraocular Implant Society, Vol. 3(3 & 4), July-October 1977, p. 180-181Kaufman, H.E. , Jeffrey Katz, et al, Corneal Endothelium Damage with Intraocular Lenses: Contact Adhesion Between Surgical Materials and Tissue, Science, Vol. 198(4316), Nov. 4, 1977, p. 525-527.While the above coatings of MC and PVP helped protect the corneal endothelium during surgery, they had several shortcomings. A supply of methylcellulose used by Dr. Kaufman in the above publications was obtained from him and tested. It was found to be a very poor film former and tended to bead up on the PMMA lens exposing edges of the lens. It has been found that MC has a very fast dissolution rate. Dipping of lenses in MC or PVP is useful to protectOMPI the corneal endothelium. However, because of the fast dissolution rate of these polymers and the difficulty of placing a controlled amount of such polymers on the lenses, the extent and length of time of protection is uncontrollable. Because of the wet and slippery nature of lenses dipped during surgery, the lenses are difficult to handle and a portion of the coating may drip off. In addition, MC and PVP solutions must be sterilized prior to dipping. The amount and type of contact with the corneal endothelium varies with the skills and techniques of different ophthalmic surgeons. It is highly desirable to have a coating that protects against both static and dynamic sliding contact.Disclosure of InventionThe present invention overcomes the above problems by providing ah adherent film coating that dissolves very slowly in water. This coating is on an intraocular lens or ophthalmic surgery tool and is supplied in a dehydrated state to the ophthalmologist who rehydrates the coating immediately prior to surgery. This coating, such as polyvinyl alcohol, clings to the lens or the like and maintains at least 40% of the coating on the lens for at least 30 minutes when submerged in a water bath simulating the wet surgical site. The coating is dissolvable in approximately 24 hours or less after surgery so as not to remain on the lens.The present application deals with the the coated intraocular lens and surgical tools themselves. A related co-pending application by the same inventors entitled Method Of Treating Intraocular Lens Or The Like, filed in the United States of America on 30 November 1977, S.N. 855,962, deals with the method of coating, dehydrating, and rehydrating a lens or surgical tool.Brief Description of DrawingsFigure 1 is a rear prospective view of an intra- ocular lens coated according to this invention;Figure 2 is an enlarged sectional view taken along line 2-2 of Figure 1 showing the coating in a dehydrated state; Figure 3 is an enlarged sectional view similar to that of Figure 2, but showing the coating in a hydrated state; Figure 4 is a sectional view schemati¬ cally showing the intraocular lens implanted within an eye; and Figure 5 is a fragmentary prospective view of coated tip sections of an ophthalmic surgery forceps.Best Mode for Carrying Out the InventionFigure 1 shows the rear of a typical intraocular lens with an optic section indicated generally as 1. To this optic section are secured a pair of iris engaging retention loops 2 and 3 that include shank sections, such as 4, 5, 6, and 7 securing the loops to the optic portion of the lens.A lens coating shown as 8 covers the entire front surface of the optical portion 1 of the lens. It is the front surface of this lens that is most likely to contact the corneal endothelium during surgery. The coating covers a peripheral edge of the lens, as at 9, and can also include a circumferential band 10 on a back surface of the optical section 1, if desired. Thus, all portions of the intraocular lens that are likely to contact the corneal endothelium are adequately protected. The iris retention loops are not coated, because the coating bridges the loops and accumulates excessive material on the loops. It is desirable to keep the coating material to a minimum'BUR£40Λ1PI a ount so it does not biologically interfere with the function of the eye and can readily be absorbed by the body. It is believed that such coating of this invention is removed from the eye through the continuous biological flushing of the anterior chamber. The dissolved material is eventually excreted through the urine or metabolized.Figure 2 shows the coating after it has been applied and dehydrated to remove substantially all of the water in the coating during the application step. The lens with the dehydrated coating is encased in a microbial barrier package and then sterilized. Thus, the sterile precoated lens with its dehydrated protective layer can be stored and shipped to the ophthalmologist. Because many different types of packages could be used, it is not believed necessary to schematically illustrate a package nor to illustrate the sterilizing equipment.In Figure 3, the dehydrated coating 8 has been submerged in an aqueous medium, such as a balanced salt solution. After a few minutes in the aqueous media, the dehydrated coating rehydrates and swells to a thickness at least 1/3 greater than its dehydrated thickness. This swollen coating has a property of sluffing off outer portions of the coating during sliding contact with the corneal endothelium. It also protects the endothelium from contact with the len's optical section 1 during static touch contact to the endothelium. The sectional view of Figure 4 shows a schematic of a human eye with the optical section 1 implanted and retained by loops 2 and 3 which are secured behind the iris 11. In Figure 4, the optical section 1 is shown in the eye's anterior chamber. It is understood that this invention could be used on anterior chamber ienses, posterior chamber lenses, and lenses that use retention means other than iris loops.Once the intraocular lens is implanted, aqueous humor within the anterior chamber 12 protects the corneal endothelium layer 13 and provides a cushion between such endothelium and the optical element of the lens. The cornea, which includes the endothelium, is shown generally at 14. In Figure 4, the coating 8 has been completely dissolved off optical element 1 after implantation. It is estimated that this dissolu¬ tion takes place within about 2-24 hours.In addition to an intraocular lens, the coating can be applied to ophthalmic surgery tools, such as the tip sections 15 and 16 of a forceps. A typical forceps might be a Von Graefe iris forceps. In Figure 5, the coating on such forceps is shown at 17 and 18.The coating described above has a dissolution rate sufficiently slow so that at least 40% of the coating remains on the lens or the surgical tool for at least 30 minutes when submerged in a water bath simulating the surgical environment. During surgery, the lens is at approximately room temperature, although at times it might be slightly higher, i.e. at body temperature. This slight temperature change is believed to be insignificant because much of the time during surgery the lens and tools are exposed to air temperature. After the coating is applied to the lens or the like, it is dehydrated until it is substantially dry and has a thickness of from 5 to 300 microns. Very successful results have been obtained with coating of approximately 100 microns thick. Plural coatings can be applied to build up this thickness. Once rehydrated BTSREA!/-OMPI- by the ophthalmic surgeon, the coating swells to a thickness of from 10 to 1000 microns. The hydrated coating is preferably at least 1/3 thicker than the dehydrated coating. A test was performed to determine the dissolution time of various water-soluble polymers coated on a PMMA intraocular lens as a function of time in a volume of liquid approximating that of the anterior chamber. Percent of weight loss of the coating as a function of time in the volume of water was calculated. The procedure involved placing a coated lens into a volume of approximately 0.2 ml distilled water. After a specified time, the lens was removed and placed on a filter pad and dehydrated for 2 hours and weighed. Weight loss was calculated and the procedure repeated until the coating had completely dissolved. The water bath was replaced with clean water after 1 hour of accumulative soak time to simulate the biological flushing action of the eye. The representative cumulative weight loss percents were plotted against cumulative time in the water bath. The following are the test results.%_ Coating RemainingMaterial Thickness No. of Coats After 30 MinutesPVP 156 μ 2 • 25%PVA 108 μ 3 75%HPC 122 μ 4 50%HPMC 98 μ 4 50%Dextran 200 μ 1 0%HES 236 μ 1 0%MC Poor fi .1m former; beaded up to expose edges of lens; and dissolved very quickly.OMPI \\ In the above tests, the abbreviations are as follows:HPMC (hydroxypropyl methylcellulose) ; HPC (hydroxy- propyl cellulose) ; HES (hydroxyethyl starch) . Because methylcellulose as tested by Dr. Kaufman and other would not stick to the lens, it was disre¬ garded as a proper coating. It may be possible to blend methylcellulose with other adherent film formers or to specially treat the lens to get better adherents to approximate the coating film described in the present invention. It has been shown unaltered methylcellulose applied to an unaltered PMMA lens as in the work by Dr. Kaufman and others is a poor lens coating for the reasons specified above. While the most successful tests to date have been made with polyvinyl alcohol, other water-soluble and swellable polymers meeting the above criteria of the applicants could be used. Possible other polymers are hydroxypropyl methylcellulose, hydroxypropyl cellulose, and Jaguars. Jaguar is a trade name ofStein-Hall Specialty Chemicals for their guar gum and guar drivatives. It is also possible to use mixtures of materials to form a coating that is both (1) an adherent film former and (2) has a slow dissolution rate to maintain at least 40% of the coating on the lens or the like for at least 30 minutes according to this invention.During portions of the surgery, the coated intraocular lens or surgical tool is not in the wet surgical site, but is exposed to air. It is important that the coating in its swollen hydrated state does not quickly dehydrate when subjected to air. It is been found that the polyvinyl alcohol coating will maintain its swollen hydrated state for at least 20 minutes when exposed to ambient air. The intraocular lens or surgical tools can be conveniently coated by dipping into a 5% aqueous solution of polyvinyl alcohol. Preferably, two dip coats are applied allowing the lens or tool to air dry between dips.In the above description, a specific example has been used to illustrate the invention. However, it is understood by those skilled in the art that certain modifications can be made to this example without departing from the spirit and scope of the invention. | Claims1. A device having a surface likely to contact a corneal endothelium during ophthalmic surgery, characterized by: a water-soluble adherent film coating on such surface for protecting the corneal endothelium, and this coating has a dissolution rate sufficiently slow so that at least 40% of the coating is maintained on the device for at least 30 minutes when submerged in an aqueous media at room temperature that has a volume simulating that of aqueous humor.2. The device according to Claim 1, wherein the device is an intraocular lens and the aqueous media is approximately 0.2 ml of water.3. The device according to Claim 1 or 2, wherein the coating is in a dehydrated state with a thickness of 5 to 300 micron.4. The device according to Claim 3, wherein the dehydrated coating is sterile.5. The device according to Claim 1 or 2, wherein the coating is a swellable polymer.6. The device according to Claim 1 or 2, wherein the coating is in a swollen hydrated state with a thickness of 10 to 1000 micron and this swollen coating has a sluffable outer portion.7. The device according to Claim 6, wherein the coating is capable of maintaining its hydrated state for at least 20 minutes when exposed to ambient air.8. The device according to Claim 6, wherein the coating is dissolvable in the aqueous media in less than 24 hours to expose at least a portion of the underlying surface of the device.9. An intraocular lens with an optical section, and this lens is characterized by: a polyvinyl alcohol coating on at least a portion of the optical section.10. An ophthalmic surgery tool having a tip section, characterized by: a polyvinyl alcohol coating on at least a portion of the tip section. | AMERICAN HOSPITAL SUPPLY CORP | KNIGHT P; LINK W |
WO-1979000327-A1 | 1,979,000,327 | WO | A1 | XX | 19,790,614 | 1,979 | 20,090,507 | new | A61F9 | null | A61F2 | A61F 2/16B, A61F 2/16C, K61F 2/00L2 | METHOD OF TREATING INTRAOCULAR LENS AND THE LIKE | A method of treating and intraocular lens (1) or ophthalmic surgical tool with a water-soluble adherent film forming material such as polyvinyl alcohol, in a liquid media after which the liquid media is evaporatively removed to provide a dehydrated coating (5 of Figure 3) that is both water-soluble and liquid swellable. The device is packaged and sterilized, such as by ethylene oxide, and supplied to the ophthalmologist. Immediately prior to its use in surgery, the ophthalmologist rehydrates the coating by submerging in a sterile aqueous bath causing the coating to swell into a soft sluffable cushion (5 of Figure 5) for protecting a corneal endothelium during both static touch contact and dynamic sliding contact with the coated lens or tool. | DescriptionMethod of Treating Intraocular Lens and the LikeTechnical FieldThis invention relates to a method of coating an intraocular lens to protect a corneal endothelium during surgical implantation.Background ArtH. E. Kaufman, M.D. and others have identified a serious problem in intraocular lens implantation dealing with the destruction of corneal endothelium cells. It is generally recognized that the corneal endothelium will not regenerate itself and is extremely important as a boundary layer between the outer layers of the cornea and the aqueous humor in the anterior chamber of the eye. The corneal endothelium is. extremely delicate in that the endothelium is only one cell thick.The intraocular lenses commonly implanted ate of a polymethylmethacrylate (PMMA) material which has excellent optical qualities and biocompatibility once it is surgically implanted. Once implanted the location of the intraocular lens is such that, when in its proper position, it does not contact or damage the corneal endothelium. There is a continuous washing or flushing of the anterior chamber including the corneal endothelium.During surgical implantation of an intraocular lens, the cornea is surgically opened and the intra- ocular lens manipulated in place frequently with retention loops placed behind the iris. Sometimes the manipulation includes puncturing the iris with a minature saftey pin type prong or clip to attach the lens to the iris.During the surgical implantation and manipulation, it frequently happens that the corneal endothelium is staticly touched or dynamically scraped with a PMMA lens or surgical tool. Dr. Kaufman and others have recognized the problem of corneal endothelium damage during surgery and have proposed dipping the lens in a coating of methylcellulose (MC) or polyvinylpyrroli- done (PVP) . These coatings were applied by the ophthalmologist immediately prior to surgery as a wet and slippery coating on the lenses.Dipping of the lenses in MC or PVP is useful to protect the corneal endothelium. However, because of a fast dissolution rate of these polymers and the difficulty cf placing a controlled amount of such polymers on rhe lenses, the extent and length of the protection is uncontrollable. Because of the wet and slippery nature of the lenses dipped during surgery, the lenses are difficult to handle and a portion of the coating may drip off. In addition, MC and PVP solutions must be sterilized prior to dipping. Subsequently, Dr. Fechner (citation below) published , the results of a repeat of the Dr. Kaufman et al experiments with a complicated attempt to sterilize methylcellulose in very small quantities to keep it from coalescing and changing viscosity. In practice, the complicated procedure described for the sterile methylcellulose coating is not feasible for the ophthalmologist to perform in the operating room.The background publications by Dr. Kaufman et al explaining the corneal endothelium damage during intraocular lens implantation and experiments with methylcellulose and polyvinylpyrrolidone coating are as follows.OMP Kaufman, H.E. and J.I. Katz, Endothelial Damage From Intraocular Lens Insertion, Inv. Ophth. , Vol. 15(12), Dec. 1976, p. 996-1000Kaufman, H.E., Jeffry Katz, et al, Prevention of Endothelial Damage From Intraocular LensInsertion, Tr. Am. Acad. Ophth. & Otol. , Vol. 83, Mar-Apr. 1977, p. 204-212Kaufman, H.E. and J.I. Katz, Pathology of the Corneal Endothelium, Inv. Ophth. Visual Sci., Vol. 16(4), April 1977, p. 265-268Fechner, P.U., Methylcellulose In Lens Implanta¬ tion, Jour. Amer. Intraocular Implant Society, Vol. 3(3 & 4), July-October 1977, p. 180-131Kaufman, H.E., Jeffrey Katz, et al, Corneal Endothelium Damage with Intraocular Lenses:Contact Adhesion Between Surgical Materials and Tissue, Science, Vol. 198(4316), Nov. 4, 1977, p. 525-527.Disclosure of Invention The present invention includes a method of pre- coating an intraocular lens or surgical tool with a liquid media containing a water-soluble adherent film forming material, such as polyvinyl alcohol, and then removing the liquid media by evaporation. The lens or tool with its firmly adherent dry coating is then packaged and sterilized, such as by ethylene oxide.Immediately prior to its use in surgery, the ophthalmologist rehydrates the lens or tool simply by dipping it into a sterile liquid of normal saline or a balanced salt solution. This swells the coatingOKPI ' into a spongey sluffable protective layer that protects the corneal endothelium during static touch contact as well as dynamic sliding contact with the coated lens or surgical tool. After implantation, the continual flushing action of the anterior chamber of the eye removes the coating from the lens in a period of several hours.The present application deals with the method of treating the intraocular lens or surgical tool. A related application by the same inventors is entitled Coated Intraocular Lens anό the Like, filed in the United States of America on November 30, 1977, S.N. 855,961, relates to the coated lens and surgical tools themselves.Brief Description of DrawingsFigure 1 is a rear prospective view of an intra¬ ocular lens which has been coated according'to such process; Figure 2 is a schematic view showing the dip coating step of the process; Figure 3 is an enlarged sectional view of the lens after its coating has been dehydrated; Figure 4 is a schematic view showing the lens submerged in a liquid during the rehydrating step; Figure 5 is an enlarged sectional view showing the swollen coating in rehydrated state; and Figure 6 is a prospective view of an ophthalmic surgery forceps with the rehydrated coating on such tip sections.Best Mode for Carrying Out the InventionFigure 1 shows a typical intraocular lens with an optical section shown generally at 1 with a pair of looped sections 2 and 3 that are joined to the optical section by shank portions, such as at 4. The optical section 1 has a coating 5 that covers its•BURHOMPI. IA *yIΛ , WiPO entire front surface, its outer edge, and a circumfer¬ ential band 6 at its rear portion. If desired, circumferential band 6 could be eliminated with the coating covering only the optical section's front and peripheral edge.It is preferable that loop sections 2 and 3 not be coated, because such coating tends to bridge the loop sections and introduce more coating material into the eye than is actually needed. The front and peripheral edges of the optical section 1 are those areas of the intraocular lens most likely to contact the corneal endothelium.The method of making the intraocular lens of this invention includes forming the lens, and then dipping only that portion intended to be coated in a water solution of the water-soluble material. Excellent results have been obtained by dip coating the -lens in a 5% aqueous solution of polyvinyl alcohol. Although 5% concentration of polyvinyl alcohol (PVA) is used, the concentration could be varied from 1% to 60% depending upon the thickness of coating desired and the number of dips. Preferably two dip coats are applied with an air drying step between the coats.Once the complete coating has been applied, the water or other liquid media is removed by evaporative drying. A substantially dry very adherent film remains on the lens. It is important that the coating material be a good film former and not bead up to expose certain uncoated areas of the lens. Polyvinyl alcohol is an excellent film former.The lens as shown in Figure 3 with its substan¬ tially dry coating is then packaged and subjected to sterilization, such as by ethylene oxide. Because there are many different package designs that could be used, it is not believed necessary to schematically show a package nor to illustrate the equipment for sterilizing such packaged lens.The lens in its packaged sterilized form with its dehydrated coating is supplied to the ophthalmolo- gist. Immediately prior to insertion of the lens, the ophthalmologist rehydrates the lens by submerging it in a sterile liquid, such as normal saline or a balanced salt solution. After this rehydration step, which takes approximately 1 to 10 minutes at room temperature, the coated lens has a swollen cushion as shown in Figure 5. Good results have been obtained with rehydration for 5 minutes. It is estimated that the hydrated coating has a thickness of approximately 10 to 1000 microns, while the dehydrated coating has a thickness of approximately 5 to 300 microns.Once the intraocular lens has been surgically implanted, the continuous biological flushing action - of the aqueous humor in the anterior chamber dissolves the coating from the lens. The coating is believed to eventually be excreted through the urine.Figure 6 shows a rehydrated coating 7 and 8 on tip sections 9 and 10 of an ophthalmic surgery tool that is likely to contact the corneal endothelium. An example of such tool is a Hirshman spatula. Once the intraocular lens or surgical tool has been rehydrated as explained above, it is important that a rehydrated film does not quickly dehydrate when exposed to air. It is been found that the polyvinyl alcohol in rehydrated form will maintain its rehydrated state in a time range of 20 minutes to 1 1/2 hours. In a typical intraocular lens implant, the cornea is surgically opened for about 1/2 hour. Also during the surgery, the coated lens or tool is flushed with liquid and also in contact with the aqueous humor of the anterior chamber which tends to delay a dehydration of the coating by air drying.The polyvinyl alcohol coating is much superior to the previously proposed methylcellulose or polyvinyl- pyrrolidone coatings. A sample of methylcellulose used by Dr. Kaufman as the basis for his publications was obtained from him. Tests showed that this material beaded up and exposed edges of the lens. It also dissolved too quickly. A polyvinylpyrrolidone coated lens was submerged in approximately 0.2 ml of water simulating a surgical site. Approximately 25% of PVP remained after 30 minutes.The polyvinyl alcohol performs exceptionally well as a coating for intraocular lenses or the like. It is hydrophiiic, soluble in water, swellable upon rehydration, an excellent film former, performs well on both static touch and dynamic sliding tests on the corneal endothelium has slower dissolution rate than other materials previously reported. It also does not dehydrate in the operating room for a period of 20 minutes after it has been rehydrated, and is easily cleared from the anterior chamber of the eye through biological processes. When the PVA is submerged in a simulated anterior chamber, i.e. 0.2 ml of water, approximately 75% of the PVA remains on the lens.Other water-soluble polymers besides polyvinyl alcohol meeting the above criteria could also be used. Examples of such other materials are hydroxy- propyl methylcellulose, and hydroxypropyl cellulose which retain approximately 50% of the coating weight when submerged in a simulated ocular surgical site as explained above. In this invention, it is preferable that the coating retain at least 40% of its weight after such submersion for 30 minutes. Should different materials meeting the above criteria be used, they would still be processed through the dehydrating, sterilization, and rehydrating step to provide very convenient precoated intraocular lenses and surgical tools to the ophthalmologist. This method could be used with anterior chamber lenses, posterior chamber lenses, and lenses which use retention means other than iris loops.In the previous description, specific examples have been used to describe the invention. However, it is understood by those skilled in the art that certain modifications can be made to these examples without departing from the spirit and scope of the invention. | Claims1. A method of precoating a device having a surface likely to contact a corneal endothelium during ophthalmic surgery, characterized by: coating such surface with a liquid media containing a water-soluble adherent film forming material; and removing the liquid media from the surface to provide a substantially dry water-soluble film on the surface.2. The method according to Claim 1, wherein the method further includes enclosing the precoated device in a microbial barrier package and steril¬ izing such package and device.3. The method according to Claim 1, wherein the water-soluble coating is also water swellable, and the method further includes rehydrating the substantially dry water-soluble coating to a swollen state.4. The method according to Claim 3, wherein the rehydration step is accomplished by submersion of the substantially dry swellable film in an aqueous bath for a period of 1 to 10 minutes.5. The method according to anyone of Claims 1-4, wherein the precoating is performed on an intra- ocular lens for implantation in an anterior or posterior chamber of an eye.6. The method according to Claim 5, wherein the intraocular lens has an optical section and one or more iris retention loops, and a major portion of the iris retention loops are free of water- soluble coating.7. The method according to anyone of Claims 1-4, wherein the precoating is performed on an oph- thalmic surgery tool.8. The method according to anyone of Claims 1-4, wherein the film forming material is polyvinyl alcohol.9. A method of preparing a precoated device for ophthalmic surgery, characterized by: subjecting the device to an aqueous environment immediately prior to surgery to swell the coating into a soft cushion which firmly adheres to the device and has an outer sluffable portion; and removing the device from the aqueous environment for use in surgery.10. A method of treating an ophthalmic surgical device, characterized by: precoating at least a portion of the device with a water-soluble and water swellable adherent film forming coating material dissolved in an aqueous media; dehydrating the precoated device to remove the aqueous media to provide a substantially dry coating of the material on the device; enclosing the precoated device in a microbial barrier package; sterilizing the package and enclosed precoated device; removing the sterile precoated device from the package; and rehydrating the substantially dry film by subjecting the film to an aqueous environ- ment immediately prior to surgery.OMPI A . WϊPO | AMERICAN HOSPITAL SUPPLY CORP | KNIGHT P; LINK W |
WO-1979000331-A1 | 1,979,000,331 | WO | A1 | XX | 19,790,614 | 1,979 | 20,090,507 | new | B60S3 | B64F5 | B60S3, B64D15, B64F5 | B64F 5/00B | A DE-ICING AND CLEANING SYSTEM FOR AIRCRAFTS | The problem to be solved is to provide rapid, efficient and safe de-icing and cleaning of primarily aircrafts. The problem is solved by a de-icing and cleaning system comprising one or more devices for spraying the object in question, preferably aircrafts, with a liquid or gas or irradiating the object, and means for sensing the position of the object in relation to said devices, which means are disposed to control said devices to automatically start and stop the spraying and irradiation in response to the position of the aircraft in relation to the devices. | A de-icing and cleaning system for aircrafts .The factors defining the aerodynamic characteristics of an air¬ craft is on one hand the geometry of the supporting surfaces and on the other hand the surface smoothness of the supporting sur¬ faces . Rough surfaces may deteriorate the flying performance to a considerable degree . Ice and snow coatings may cause so rough surfaces that flying is rendered impossible . During flight the built-in de-icing system of the aircraft is sufficient but at ground intervals de-icing must be performed before start under unfavourable meteorological conditions .In certain cases it might be sufficient to sweep the wings clear of loose snow but more efficient actions are most often required. In general a hot mixture of water and gl col is sprayed, whereby the glycol provides a certain preventive effect, which is inten¬ ded to remain , until the aircraft has climbed into the air . Upon heavy snow fall the treatment must be performed immediately be¬ fore start. The spraying of the de-icing liquid is generally performed by a team consisting of a spraying machine operator and a driver , who drives the tank truck with the spraying machine . The spraying machine operator stands on a lifting platform, from v/hich he treats those portions of the aircraft which can be reached by the jet from the spraying machine . The truck is driven around the aircraft so that all portions of the aircraft can be treated.Under favourable conditions the aircraft is occupied for only about five minutes by the treatment but time studies have shown that on the average a team will work 45 minutes on each aircraft . It is not rare that .delays of air services occur because many planes are queueing to be de-iced. Th s , de-icing will frequent¬ ly cause a bottle-neck in the traffic capacity of the air port .The method has been critici zed, since excess glycol may penetrate into the ground and in the long run ruin the ground water.In order to reduce these risks special locations have been ar¬ ranged at 'the new air ports of Paris and Montreal , is to be performed. Through drainage sys tems the treatment liquid can be recovered and re-used . De-icinσ is performed by the aircraft by its own engines passing between two large scaffolds , on which 4 to 6 men are placed. By means of hand- operated jet nozzles the men spray the aircraft as it passes .In Sweden the authorities have developed an interest in the hea risks of the method for the s taff involved. Stricter safety dir tives have been issued. In US patent specification 791 024 a central de-icing installat is disclosed consisting of a pair of in the longitudinal direc¬ tion of the aircraft self-propelled towers on either side of th air-craft. Each tower is provided with a hinged boom, which ex¬ tends inwardly over the aircraft . By means of a plurality of hinges the boom is pivotable in the vertical plane . The boom carries a conduit with nozzles for spraying de-icing liquid or compressed., air. The installation is intended to operate so that the towers are driven in pairs externally of the wing tips alon the parked aircraft. The inwardly projecting boo'ms and their hinges are actuated so that the nozzles of the conduit are lo- cated adj acent and directed towards the surfaces to be de-iced. The purpose appears to have been to solve the problem of rapid¬ ly spraying the necessary surfaces of the aircraft. The Canadian patent specification 150 370 discloses an installa tion for recovering and re-using de-icing liquid and arrangeme for spraying de-icing liquid. .In a system of ducts on the parking ramp the de-icing liquid ru off from the aircraft , is then collected and conducted in pipes to a purification plant. After having been analyzed in respect of dilution the liquid can either be rejected (should tie glycol content be too low) or else be treated by freezing or destina¬ tion so that the concentration of glycol is increased. If re¬ quired, fresh glycol is added to the solution , which is finally heated and stored in a s torage tank , until it is to be used again . The inventor of this sys tem appears to presume that a de-icing liquid should be used consisting of a solution of app¬ roximately equal parts of water and glycol . For the spraying of the de-icing liquid it is indicated that two or four vehicles should be placed at strategical locations on the de-icing ramp . Each vehicle is provided with a two-part boom, which is moved inwardly towards the parked aircraft. The boom carries a conduit with a nozzle , through which the liquid is sprayed onto the aircraft .The object of the present invention is to provide a more rapid , efficient and safe de-icing at a lower cost and without risks for the staff and the environment. It is discussed below how the 10 present invention , in preferred embodiments thereof , will ful¬ fil these requirements in comparison with other types of instal¬ lations .A more rapid de-icing is attained by having the aircraft to pass through a stationary de-icing installation , all surfaces of the 5 aircraft being treated as they pass the spraying device . Without time delay also downwardly and laterally directed surfaces are de-iced . The treatment time will be a fu n ction of the velocity of the aircraft through the installation and will depend only on the fact that the aircraft must spend sufficient time to be 0 sprayed with the required amount of treatment liquid . The dimen¬ sions of nozzles , valves , pumps , etc. included in the spraying device will thus determine the treatment time . The costs for sufficient dimensions of these standard articles are trivial in this connection and will hardly form any restricting factor. 5 If it is assumed that the aircraft is driven through the plant or ins tallation at a velocity of 6 km/h (fast walking speed) the treatment time will be 42 sec . for an aircraft with a length of 70 m.In plants according to US patent specification 791 024 the treat- 0 ment time will be equal to the maximum time required, for either moving the arrangement along the length of the aircraft , or for the operator to actuate all booms and valves . To be capable of treating the largest commercial airplanes of today the two in¬ terconnected towers mus t have a dis tance of about 65 m between 5 the support points on the ground and a free internal height of about 21 m. . Since the structure also mus t carry s torage tanks for the treatment liquid , driving engines , pumps , cabins for_O.V.PI the staff, a plurality of large, movable booms, etc., it is evident that it will be of such dimensions that it cannot reas ably be moved as rapid as an airplane is running. The installa tion comprises a plurality of booms, which are to be moved and pivoted in a vertical direction at the same time as several te of valves are to be opened and closed. It is hardly possible f one operator alone to manage to perform all these operations w in a half minute or somewhat more, which are at disposition, i the plant is to be competitive.In installations according to the Canadian patent specificatio 150 370 a plurality of relatively conventional vehicles is use and the spraying is controlled manually. Consequently, the tre ment time will depend on the amount of vehicles and staff to b used. Said patent specification hardly provides any improvemen as compared with conventional methods in this respect.A more efficient de-icing is provided according to the present invention, on one hand, by the automatization of the spraying process and, on the other h-and, by the separation of the remed melting of snow and ice from the preventive spraying with glyc The automatization makes it possible for experts to define the absolutely most efficient treatment process in the form of a program and this process is then identically repeated at each treatment. The separation of remedying and preventive de-icing makes spraying of the airplane with concentrated glycol as the last treatment before start possible, concentrated glycol havin a longer remaining preventive effect than the 50% glycol soluti which is used at present and is supposed to be used according the two cited patents.Safety in flight will thus be increased both by the two feature of the present invention as mentioned above and by the rapidity of the process, which removes any temptation in situations hard to judge to refrain from de-icing for avoiding delays.The requirement of safer de-icing in this connection means that the process must not be dangerous to the aircraft and its cargo and that the operative reliability should be high. introduce any new type of risks for the aircraft . If the por¬ tals are made sufficiently wide , there will hardly be any risk of collision . The reliability in operation of the spraying de- vice will be high , since the number of movable parts is limited.The reliability of the apparatus recovering the treatment liquid will be high , since unmixed liquids are used, whereby simple and uncomplicated means can be utilized.Plants according to the US patent specification 791 024 are pro- vided ith a plurality of movable booms of subs tantial si ze , sup¬ ported by a movable structure . Since de-icing is to be performed immediately before start, the aircraft will be fully tanked and fully loaded when it is de-iced. A malfunction or an incorrect operation of any one of the many movable parts may therefor have disas trous consequences . Further , a large niamber of movable parts have an unfavourable influence on the reliability in operation .The Canadian patent specification 150 370 discloses a recovery- plant , the object of which is to analyze the treatment liquid which has run off and restore the glycol concentration to the values desired . All checking and control problems with the acco - panying risks of interruption of the service caused thereby are avoided by the use of unmixed liquids , which is according to the present invention .The total costs of de-icing can be separated into capital costs for the plant , operating costs in the form of staff costs , costs of material and other costs of operation and traffic costs for the aircraft treated.The sys tem according to the present invention affords lower . total cos ts than both methods presently used and the systems according to the mentioned patent speci fications for all airports , except poss ibly for such with the smalles t traffic .The sys tem according to the invention , due to the s tationary location and the simple design thereof , will be more economic to cons truct and maintain . The possibility of uti li zing the plants also for the cleaning of aircrafts will distribute the fixed • cos s s . ¬ duce the staff cos ts to a minimum. The recovery of the treatmen liquids will reduce both the consumption of liquids and the heating costs . The traffic costs for a treated aircraft can be assumed to be directly depending on the time during which the aircraft due to waiting or de-icing is prevented from performin useful traffic work . The great capacity of the system will keep these costs low . Finally , the improved safety in flight should be attached a considerable value , also in economic terms .Risks of health for the staff are eliminated, on one hand, by the automatization rendering all staff unnecessary , possibly with the exception of a supervisor, and, on the other hand , by the possibility of placing the staff indoors . The risks for the external environment are reduced, since all treatment liquid is circulating within a closed system.An exemplary , preferred embodiment of the invention will be des ribed below. The drawings comprise Fig. 1*, which shows a fronta view of the sys tem according to the invention . Fig . 2 , illustra ting a prinicipal sketch of a programming assembly in the syste according to the invention , Fig. 3 , which shows a cir c it dia¬ gram of a part of the programming assembly , and Fig . 4 a princi pal diagram of a wind compensator in the system according to th invention .The aircraft to be de-iced is running through one or more sta- tionary portals 1 , see Fig. 1. Each portal supports a conduit 2 which is provided with a plurality of nozzles 3 directed toward the aircraft 10 . Through the nozzles the treatment liquid is sprayed onto the aircraft. The spraying is individually control led by means of a remotely controlled valve for each nozzle .If several different types of aircraft are to be treated, the conduit 2 must be designed in such a manner that the largest ' aircraft 10 can pass unimpeded therethrough . If a small aircraf is treated the conduit in this case will be far away from the aircraft , which causes action of wind and cooling of the liquid jets to be considerable . In order to avoid this disadvantage , t portal 1 may. support a plurality of different conduits , which a designed so that they closely conform with the profile of the aircraft as seen from the front. These conduits can be lifted in the portal. The conduit designed for the largest type of air¬ craft is fixedly mounted and when it is to be used, all other conduits are lifted thereover, so that they do not impede the pas¬ sage of the aircraft. When a smaller aircraft is to be treated, the conduit designed therefor is lowered into operating position. Treatment liquid is sprayed only through those nozzles 3 that are mounted on the conduit used for the occasion.At present it appears to be conventient to use two portals 1, one for the spraying with hot water and one for the spraying with non- diluted glycol. At the first portal all snow and ice is washed off by hot water. An abundant spraying will secure a good result with¬ out other disadvantages than increased heating costs for the water.At the second portal 1 the aircraft 10 will receive a showering of concentrated glycol, which prevents coatings of snow and ice until the aircraft is airborne. A thrifty and accurately directed spraying is desirable in order to avoid a film of glycol on the windows and glycol in the engines and in air conditioning instal- lations.The system according to the invention may also be designed with only one portal 1, if it is to be used for the spraying of only one liquid or with three or more portals, if it is intended for spraying the aircraft with a corresponding number of different liquids.The portals 1 are disposed over a roadway 11 for the aircraft 10 prepared for this puspose. The roadway is provided with a system of draining ducts 4, 5 for each portal. The draining ducts collect the liquid sprayed beside the aircraft or having run off the air- craft. The treatment liquid is conducted to a collecting tank 6 and therefrom to an installation 7 for purification and possibly heating or destination, before it is pumped into a storage tank 8. From the storage tank the liquid is again pumped 9 into the con¬ duit 2, when the next aircraft is treated.The distance between the portals is determined by how long dis-OKPI tance the wind can force the jets of liquid . The portals should be so far from each other that the different treatment liquids not mixed on the ground. By using unmixed and non-diluted liqui and keeping them separated from each other the recovery process can be made simple .The aircraft is driven along the roadway by its own engines or drawn by a tractor or by the roadway being provided with such a inclination that the aircraft will run along the roadway by its own weight, whereby the engines need not be in operation .It is also possible to design the system so that the aircraft i stationary , while the portal is displaceable along the aircraft (e . g. , on rails ) .A plurality of position sensors for the aircraft are provided along the roadway a-p i Fig . 2. The object thereof is to record how far the aircraft has reached on its way along the roadway and to provide a signal to open those valves which the aircraft has reached and to close those valves which the aircraft has pa sed. The position sensors may comprise pressure responsive mean in the roadway or photoelectric cells , which Eeact , when the air craft interrupts a light beam transversally of the roadway or metal detectors embedded into the roadway , e . g. , of the type co sisting of a coil , supplied with a high- frequency A. C . When a m tal object, e . g . an aircraft wheel , appears sufficiently close to the coil , the inductance thereof will change . The position sensing may also be performed by means of a range finder, loca¬ ted in the extension of the roadway in a direction forwards or backwards . Each range finder controls the actuating current to relays , wh ich open and close the valves 31-49 to the nozzles in the conduit. When the nose of the aircraft 10 has arrived in under the portal , the first range finder is triggered , which closes the actuating current to the relays that open the val¬ ves being di rected towards the nose of the aircraft , whereby the treatment liquid is sprayed onto the nose of the aircraft. As the aircraft passes in under the portal , the position sensor are triggered one by one and the sprayinq from the various nozz les is s tarted and interrupted , as the aircraft s urfaces pass b( _ 0'V-PI e nozz es. or a conven e n a rc a r nozzles will be open and spraying all the time from the moment the nose tip arrives in under the portal until the most rear¬ ward tail tip has passed under the portal. The most external nozzles spraying the wing tips, on the other hand, will be open only from the moment the front edges of the wing tips pass the nozzles until the rear edges of the wing tips pass the nozzles.Which valves are to be opened or closed, when a certain position sensor is triggered, is determined by e.g. an electronic printed circuit card or the like, which is adapted to the type of air¬ craft to be treated. The printed circuit cards are made replace¬ able so that different types of aircraft can be treated.Fig. 3 shows in a section of a circuit diagram how the position sensors g,h, and i actuate the valves 31, 32, 33 and 34 through the- relays g31~, g32~, g33~, g34~, h31 , h32', h33~, h34 , i31~, i32 , i33* and 134 .The nose wheel of the aircraft triggers the position sensor h, whereby the control circuit is .closed and the actuating current passes from the current source 20 through the relays h34 , h33~ and h32'. Fine lines in Fig. 3 indicate leads for the actuating current, and thick lines symbolize the operating current. The re¬ lays h32 , h.33 and h34 then close the operating current from the source 22 of operating current to the valves 32, 33 and 34, which are opened so that the treatment liquid is sprayed through the nozzles.In the next moment the aircraft will leave the position sensor h, whereby the control circuit is opened and the relays h32~, h33'', and h34~ will then be without current and break the operating current to the valves 32, 33 and 34, which will thus stop the spraying of liquid through the corresponding nozzles. As the air¬ craft leaves the position sensor h, however, it will trigger the position sensor , which, according to the circuit diagram, will open the valves 31 and 32 via the relays i31 and i32 .The leads for the actuating current are assembled on a printed circuit card A and by means of contact members connected to the position sensors i ,h , g , the current source 20 and the relays i31'- 34 ' , h31 '- 34 , g31'- 34 ' in a pattern adapted to the type or aircraft to be treated.Fig. 2 shows the general design of the printed circuit card for a Boeing Model 747-200 with a span of 59 .64 m and a length of70 . 66 m. A McDonnell- Douglas DC-9-21 has a span of 28. 45 m. The wing tips thereof will reach just outside the inner engines of B- 747 , and therefore a printed circuit card for a DC-9-21 would not on any occasion switch on the valves 31 , 32 , 33 , 47 , 48 and 49 , since they are located outside of the wing tips . When side wind the condition may be changed by the wind compensator , see the description thereof . A DC-9-21 is 31. 85 m long , and therefo all spraying of liquid is terminated, when the nose wheel actua¬ tes the position sensor i , since the aircraft is then completel past the portal . When tail wind or headwind, however, the wind compensator may change this condi t ion .The wind may cause a drift of the liquid, which has a long dis¬ tance to pass between the nozzle and the aircraft. In order to secure a favourable result of the treatment, a plurality of . printed circuit cards may be formed for each type of aircraft, which are modified so as to compensate for different wind direc¬ tions and wind forces . If the distance between the position sen¬ sors is 1 m and so strong a wind is blowing straight from behin that the drift of the jet of liquid will be 1 m, a printed cir- cuit card is used, which is modi fied in such a manner that those valves that should have been opened and closed by a certain po¬ sition sensor are actuated first by the next position sensor . Measuring instruments for wind force and wind direction are used for controlling the selection of printed circuit cards .In the most primitive embodiment this is performed by the per¬ son operating the de-icing plant reading the wind force and wind - direction and selecting a printed circuit card for the type of aircraft , adapted to the wind conditions . In a more automati zed embodiment one set of printed circuit cards is provided for each type of aircraft , each individual card being adapted to a cer¬ tain wind direction as well as to a certain wind force . Wind di¬ rection indicators and anemometers connect that particular prin-' UR£ ted circuit card of the set which is adapted to the existing wind conditions. Such an arrangement would be capable of reac¬ ting to rapid variations of wind direction and wind force. The structural design of such a wind compensator is exemplified in Fig. 4.On the right hand side of Fig. 4 a wind compensator is shown, which comprises a wind direction indicator B and an anemometer C and a plate D supporting relays. On the left hand side of the figure there are shown two printed circuit cards, 0 and Nl, of totally thirteen printed circuit cards required in this example and the relay plate A with the relays h31' , h32', h33', g31', g32', g33'and g34'. To the far left the position sensors g,h, and i are shown. At the bottom of the illustration the valves 31, 32, 33 and 34 are shown.The wind direction indicator B comprises a centrally pivoted, rotatable contact arm 50 and a vane or the like (not shown) , which turns the contact arm a convenient number of contact plates 52, 54, 56, 58, one for each wind direction. In the Fig. 4 the use of four wind directions is shown, N,E,S and W but it is understood that more or fewer may be used. Via the contact arm an actuating current (fine, broken line) is supplied to one of the four contact plates and therefrom to the relay plate D.The anemometer C comprises a movable contact arm 60, a centri¬ fugal regulator or the like (not shown) , which moves the con- tact arm from one end position when no wind to the other end po¬ sition at maximum wind force, and a suitable number of inter¬ mediate contact plates, one for each wind force interval. In the embodiment illustrated four wind force intervals are used, 0 for no wind and III for maximum wind force, with the inter- mediate positions I and II, but more or fewer intervals can be used. Via the contact arm an actuating current (fine, continuous line) is supplied^ to one of the contact plates and from there to the relay supporting plate D.On the relay supporting plate D the two control currents from the wind direction indicator B and the anemometer C are combined at a number of connecting points. If all wind directions should be combined with all wind forces, 4 x 4 = 16 connecting points would be required, but since the wind direction is unimportant at the wind force = 0, only thirteen connecting points are re- quired in the example, viz.:Will, SHI, EIII, NIII, WII, SII, EII, Nil, WI, SI, El, NI, and . 0.In each connecting point two series connected relays 24, 26 are provided. One relay 24 is actuated by the control current from the wind direction indicator B and the second 26 by the anemo¬ meter C. In order to allow the operating current (thick, broken line) from the operating current source 28 to pass through the connecting point in question it is necessary that both relays are closed. In a cut out section in the illustration of the con tact point Nil it is shown that the control current from the sector N of the wind direction indicator has closed one 24 of the two relays, while the second relay 26 breaks the operating current, since the anemometer is not in position II but in posi¬ tion 0.Each connecting or contact point (i.e. Will, SIII, EIII,....NI and 0) on the relay supporting or contact plate D is connected to one particular printed circuit card. There are thus thirteen printed circuit cards in the set but only the cards 0 and NI are shown in the illustration. The remaining eleven have -been omitte for the sake of clarity.In Fig. 4 it is shown by means of small arrows how the system is working. The wind direction indicator B points towards N and control current is_ supplied to the contact points NIII, Nil and NI. The anemometer C, however, indicates 0, whereby the deffec- tion of the wind direction indicator is unimportant. Via the con tact point 0 the printed circuit card 0 is connected. Since the position sensor h is triggered, the control current will pass through the relays h34 ' , h33' and h 32 ' , which will open the valves 34 , 33 and 32 .If a blast of wind should move the contact arm 60 of the anemo¬ meter C into position I , the two series connected relays 24 , 26 in the contact point NI would close , the printed circuit card NI being connected. According to the printed circuit card NI the two valves 31 and 32 are connected , when the position sensor is in the position h . The two farthest nozzles 31 (and 49 ) in the por¬ tal , see Fig. 2 , are thus spraying treatment liquid, in spite of the wing tips having still not arrived under the nozzles . However , the blast of wind drives the jet of liquid in the direction S (it is presumed that the aircraft is moving in the direction N) , where¬ by the jet of liquid will hit the wing tip , before it has arrived in under the portal 1.The movement of the aircraft 10 relative the portal 1 can also cause to start and stop the spraying by means of a plurality of sensors , which actuate the valves to the nozzles directly without the assistance of any programming assembly . A system operating in this manner can be designed so that a number of light sources are placed in the jet direction of the nozzles , preferably in the ground but other locations may also be used. The light sources are formed and directed so that they emit a narrow light beam towards a photo-electric cell placed adjacent each nozzle . The photo-electric cell controls the electrically operated valve be- longing to the nozzle . As long as the light beam between the light source and the photo-electric cell is unbroken , the valve is kept closed by the photo-electric cell . When an object breaks the light beam, the photo-electric cell reacts and -opens the valve to the nozzle , whereby the de-icing liquid is sprayed onto the ob ject. When the object has passed the light source and the nozzle , the light beam will again illuminate the photo-electric cell , which will then cause the valve to be closed 'and the spraying to be ter¬ minated. The photo-electric cell assembly used may also be of the type having a light source and a photoelectric cell mounted ad- j acent each other , wherein the photo-electric cell reacts to light which has been radiated from the light source and has been ref¬ lected from, an object in front of the light source . In addition to light, sound can also be used for sensing the p sition of the aircraft. A device of this kind is preferably fo med so that the sound source and the sound receiver are locate in line with the jet direction of the nozzle , one beyond that of the room in which the aircraft will move and the other adja the nozzle . As long as the sound can pass unimpededly between sound source and the sound receiver, the valve to the nozzle i kept closed but when an object arrives in front of the nozzle thus deteriorates the sound transmission , the valve will be op and the spraying of treatment liquid starts .This way of controlling the treatment without using programmin assemblies enables the treatment of any type of aircraft witho any preparations , such as , e . g. production of printed circuit cards or selection of printed circuit cards . The advantage res in the fact that the system does not need to be supervised by person but can be made completely automatic, that the cost of gramming assembly is avoided and that all types of aircrafts ( all other objects ) can be treated without any preliminaries . T treatment liquid will in this system reach all parts of an air craft located in front of a nozzle , even those parts which it possibly desirable to avoid treating, e . g. , windows and air in lets . This disadvantage may be of minor importance , if a liqui is used, which is harmless to those parts of the aircraft, e . g hot water. If other liquids are used, the disadvantages can be eliminated by directing no nozzle towards the region in which e . g. , the windows of the aircraft will pass .Above it was indicated that one or more liquids are to be used as de-icing medium. However , under certain conditions gases ma be used with advantage , such as , e . g. , water steam or glycol s The advantages of using steam instead of liquid is that the he energy content per unit weight is higher in steam. Thereby the required quantity of energy for melting snow and ice can be tr ferred to the aircraft with a smaller weight of de-icing mediu Hereby the drainage installations can be designed with smaller dimensions or possibly be completely eliminated. The jet of ste has also more heat energy in relation to its kinetic energy th a jet of liquid has . If too much kinetic energy is trans ferred to the aircraft , mechanical damage will occur in the form of buckles in the sheet metal . By using jets of steam the risk of mechanical damage of the aircraft is thus reduced. As an alter¬ native it is possible , with the same risk of damage , to allow the aircraft to pass more rapidly through the portal and still receive the necessary amount of heat energy .In addition to liquid and steam it is also possible to use ra¬ diation energy for de-icing , e . g . *, light within or beyond the range of wave-lengths which are perceptible to the human eye . The use of radiation energy will eliminate the risk of mechani¬ cal damage of the aircraft . No arrangements are required for col¬ lecting and treating de-icing liquid or condensed de-icing steam. Only melted snow or ice may need to be removed. Energy losses to the atmosphere are reduced to a minimum.As a source of radiation may be used e . g . a heating lamp , a so called infrared radiator , laser or microwave generator or the type used in microwave ovens . The radiation can be controlled by means of position sensors and with or without a programming assembly in the same manner as described above for the spraying with liquid or steam.The description has so far only treated arrangements for the removal of snow and ice from aircraft. However, there is a further type of coating on the surfaces of aircrafts which con¬ stitutes an inconvenience , namely dirt . Dirt in the form of dust , soot, crushed insects , excrement of birds , etc . is deposited on all surfaces of the aircraft, both during flight and when the aircraft is standing on the ground. This process of making dirty generally proceeds rather slowly and , therefor , constitutes no risk for the safety in flight . However , the dirt impairs the sur- face smoothness of the aircraft and increases the air drag and thereby the fuel consumption . Regarding the commerci al air traf¬ fic , in addition dirt makes the aircraft look uglier , counter¬ acting the impression of perfection which every air line company are seeking .Before the accumulation of dirt has become too serious , the ai r¬ craft is therefor cleaned. This is usually performed by manual brushing of the aircraft with cleaning means and the aircraft is rinsed with clean water afterwards . The staff doing the job uses movable stairs and other staf foldings in order to reach al parts of the planes . These scaffoldings must be moved frequentl which together with the primitive cleaning methods cause the pr cess to be both time consuming and costly .The arrangements described above for ejecting de-icing liquids can also be used for ejecting cleaning liquids . It is preferabl to first have the aircraft sprayed in a first portal with a suitable cleaning liquid, which dissolves the dirt, and in the next portal the aircraft is then rinsed with clean water.The liquid is transferred to the aircraft by a jet. The kinetic energy of the jet of liquid provides a processing of the layer of dirt or ice . This processing is intensified by having the je of liquid pulsate or oscillate and by vibrating the layer of di or ice by exposing it to sound of proper frequency . The frequen of the sound is varied cyclicly for the purpose of effectively affecting the layers or coatings with different natural vibrati frequencies . The sound is transmitted to the aircraft through the liquid column which is formed through the air by the jet. T sound producing means are mounted adj acent the nozzles on the c duit for the liquid in the portal .In comparison with the manual method described above , the clean in the system according to the present invention can be expecte to be somewhat less efficient , since the mechanical treatment o the dirt layer with a brush is eliminated. However, since the method will only require a fraction of the time necessary for t manual method, it is possible to repeat the cleaning much more frequently at the same cos t and thereby attain an equal total effect or in any case extend the intervals between necessary manual cleanings .Roadway or driving path , portals , position sensors , programming assemblies , pumps , valves , no zzles , supply conduits and drainag ducts may be common for de-icing and cleaning liquids , while it might be preferable to provide separate collecting tanks , treat- ment tan s an s torage an s or eac n o qu use . system arranged in this manner can be used alternatingly for cleaning and de-icing or aircraft.By utili zing the system in this manner for two separate pur¬ poses the economy thereof will be improved .The system according to the invention has been described above as adapted for de-icing and cleaning of aircrafts . However , the prin¬ ciples of the operation of the sys tem can be used in any system which objects are to be exposed to spraying or radiation . Systems according to the invention can thus be designed for automatic sur¬ face treatment of objects in a sequence by e .g . , sandblasting , zinc spraying , ground coating , finishing lacquering and drying with heat radiation . De-icing systems may be located at s trategic points along a railway network for automatic operation when re¬ quired for melting away snow and ice accumulated on the bogies of the trains and threatening to cause interruptions of the service .O: PI | Claims .1. A de-icing and cleaning system for aircrafts, charac¬ terized in that one or more devices are provided to spray the aircraft with a liquid or gas or irradiate the aircraft and in that means are provided for sensing the position of the aircraf5 relative said devices, said means being disposed to control sai devices to automatically start and stop the spraying or irradia tion in response to the position of the aircraft relative the d vices.2. The system as claimed in claim 1, characterized in that10 said devices for spraying or irradiating comprise conduits, whi via valves are in connection with nozzles or other spraying mem bers, said conduits being supported by rigid frames, arranged i one or more portals. 3- The system as claimed in claim 1, characterized in that15 devices for spraying or irradiating comprise one or more radiat sources, which are supported by one or more rigid frames arrang in one or more portals.4. The system as claimed in claim 2 or 3, characterized in that the shape of the frames is adapted to the profile of the20 aircraft as seen from the front.5. The system as claimed in claim 4, characterized in that the frame or frames are movable in relation to the portal.6. The system as claimed in claim 2 or 3, characterized in that the number of portals is depending on the number of diffe-25 rent liquids, gases or irradiations, by which the aircraft is t be treated.7. The system as claimed in any of claims 1 through 3, char terized in that a programming assembly is provided for control ling said devices for spraying and irradiating the aircraft to30 duce a selectively controllable spraying of liquid or gas throu the different nozzles or a selectively controllable irradiation . the aircraft by the different radiation sources, said programmi assembly being responsive to said means for sensing the positio of the aircraft. _35 8. The system as claimed in any of claims 1 through 3, char terized in that said means for sensing the position of the air craft directly control the devices for spraying and irradiating the aircraft to cause a selectively controllable spraying of liquid or gas through the different nozzles or a selectively controllable irradiation of the aircraft by the different ra¬ diation sources-. 9. The system as claimed in claim 7 or 8, characterized by means for sensing the actual wind force and wind direction to control the spraying of liquid or gas or the irradiation in res¬ ponse thereto.10. The system as claimed in claim 1, characterized in that said means for sensing the position of the aircraft comprise pres¬ sure responsive elements.11. The system as claimed in claim 1, characterized in that said means for sensing the position of the aircraft comprise photo¬ electric cells. 12. The system as claimed in claim 1, characterized in that said means for sensing the position of the aircraft comprise me¬ tal detectors.13. The system as claimed in claim 1, characterized in that said means for sensing the position of the aircraft comprise sound producing and sound receiving elements.14. The system as claimed in claim 1, characterized in that said means for sensing the position of the aircraft comprise a range finding device located in the extension of the roadway along which the aircraft moves. 15. The system as claimed in claim 1, characterized by an in¬ clined roadway on which the aircraft moves, said inclination being such that the aircraft will be driven along the roadway by its own weight.16. The system as claimed in claim 1, characterized in that the roadway on which the aircraft moves, comprises one or more drainage systems for the collection of excess treatment liquid or condensed steam or melted snow or ice.17. The system as claimed in claim 16, characterized in that said drainage systems conduct the collected liquid to suitable arrangements for treatment or storage of the liquid, until it is used again.18. The system as claimed in claim 2, characterized in that sound generating means are disposed in the portal to detach coa¬ tings on the aircraft by transmitting sound of suitable frequency. | MAGNUSSON U; MAGSUSSON K | MAGNUSSON U; MAGSUSSON K |
WO-1979000332-A1 | 1,979,000,332 | WO | A1 | EN | 19,790,614 | 1,979 | 20,090,507 | new | H01M8 | null | C25B11, H01M8 | C25B 11/00, H01M 8/04 | FLUIDIZED-BED ELECTRODES AND RELATED APPARATUS AND METHODS | The current-carrying capacity of a fluidized-bed electrode is enhanced by imparting increased velocities to the particles (3) suspended therein while maintaining a relatively low degree of bed expansion or voidage. This is accomplished in one embodiment of the invention (Fig. 2) by means of pairs of opposing jets of electrolyte impinging against each other so as to effect a highly turbulent motion of the fluidized particles while the net flow velocity of the supporting electrolyte is kept relatively low. In a second preferred embodiment (Figs 3 and 4), the electrolyte flow velocity may be as high as desired, but its direction preferably horizontal, is reversed at frequent intervals. The suspended particules get thereby intermittently packed against and retained by filters (10, 11) at the alternating outlet walls (6, 7). The alternating packing and expansion result in improved charge and mass transport, and hence in improved electrode performance. The above improvement is especially applicable to fluidized beds of activated carbon particles and of other materials whose specific gravity is not much higher than that of the supporting electrolyte. | F3_UIDIZ--D-BED ELECTRODES D RELATED APPARATUS AND MEIHCDS --AQ OUND OF THE INVΣHTIQNThis invention relates to fluidized-bed electrodes, especially air-depolarized cathodes, and to related apparatus and methods.This is a (Xintinuation-in-part of my co-pending applicaτicn Se- rial Number 813, +83, filed July 7, 1977 (International Application No.PCT/US78/00030, filed 03 July 1978) which is incorporated herein by refer¬ ence. In said application, I have disclosed improved air-depolarized flu¬ idized-bed electrodes for use in various types of electrochemical process¬ es and apparatus, especially in power sources.One serious limitation of the fluidized-bed electrodes disclosed hereτofore is that the upward flow of the supporting electrolyte through the bed can not exceed a certain optimum value beyond which tne current- carrying capacity of the electrode decreases. This optimum flow corres¬ ponds to rather low bed expansions, usually about 10% or less. Higher bed expansions result in reduced interparticle contacts, and hence in re¬ duced charge transfer. To maintain the expansion sufficiently low and yet permit the electrolyte flow rate to be sufficiently high for adequate mass transDort, the specific gravity of the fluidized particles should prefer-3 ably exceed that of the supporting electrolyte by at least 2 gm/cm . This liπ tation would preclude the use of activated carbon and of other relative¬ ly light materials in fluidized-bed electrodes. Yet activated carbon has several most desirable features, including a high active surface area per u- nit weight, a high catalytic activity, and low cost, which make it an es¬ pecially outstanding candidate material for the fluidized particles in air cathodes.It is an object of iψ invention to overcome the afore-outlined lim¬ itations of present fluidized-bed electrodes, and thereby increase their CT- rent-carrying capacity. It is also an object of rπy invention to permit the use of activated carton as the chief component of the fluidized-bed electro- des, especially air-depolarized cathodes.SUMMARY OF THE INVENTIONBriefly, my invention consists of imparting the desired hijh velo-( _ ?MPI cities to the particles suspended in the fluidized-bed electrode while maintaining the bed expansion cr voidage optimally low. One way of a- chieving this is by causing opposing horizontal high-velocity inlet jets to impinge against each other, thereby causing their kinetic energy to be dissipated nto turbulent motions while the net vertical flew velocity of the supporting electrolyte is kept relatively low. ' An alternative way is to use a high unidirectional flow at any given time, but to reverse tne flow direction at frequent intervals. In tne latter case, the alternating inlets and outlets may extend over most of τhe length of the bed, so as to impart a substantially uniform average particle motion throughout the bed, and should comprise suitable filters to retain the fluidized particles with¬ in the electrode compartment. The rapid alternating flew causes intermit¬ tent partial packing of particles against the alternating outlets, and a rapid to and fro motion of the particles between the inlet and outlet sides. This yields frequent interparticle contacts and hence a high rate of mass and charge transfer.Since the particle velocities and interparticle contacts imparted by either of these types of flew do not determine the vertical bed expansion or the overall bed voidage, it thereby becomes practical to use activated car- bon and other relatively light materials as fluidized electrode catalysts. Tne high area/weight ratio of activated carbon is especially useful for ef¬ fecting adequate mass transport of oxygen in the fluidized-bed air cathode systems disclosed in my afore-cited co-pending application.BRIEF DESCRIPTION OF THE DRAWINGMy invention may best be understood with the aid of the drawing, in which:Fig. 1 is a partial schematic magnified cross-sectional view of an electrochemical cell comprising a fluidized-bed electrode;Fig. 2 is a partial schematic view of section S-S of Fig. 1 accord- ing to one embodiment of my invention;Fig. 3 is a partial schematic view of section S-S of Fig. 1 accord¬ ing to an alternative embodiment of my invention; andFig. . is a schematic diagram of a pump-and-valve system controlling the flow directions of Fig. 3. DESCRIPTION OF THE PREFERRED EMBODIMENTSIn Fig. 1 is shown an electrochemical cell 18 similar to those described in my afore-cited co-pending application. A single cαnpart- ment 28 comprises particles 3, preferably of activated carbon, in a flcw- ing electrolyte 16 contained between an outer air-permeable electrolyte- iEπper eable membrane 23 and an inner current-collecting grid 17. Near membrane 23, the surfaces of particles 3 become enriched with oxygen per¬ meating 1-hrough said membrane. This oxygen is electroreducεd as the particles approach grid.17.Electrolyte gap 19-, counter-electrode 20, insulating spacers 21, and end gaskets 22 substantially complete the electrochemical cell. As in πς. afore-cited co-pending application, electrode 20 nay be an anode consuming a hydrogen-rich fuel, a consumable metal anode forming part of a metal-air power source, or, in conjunction with a suitable diaphragm (not shewn) , an anode for the electro-oxidation of chloride ions in the r_-__nufacture of chlorine. According to one e_--oodi_τ_ant of my invention, the view of section S-S of Fig. 1, perpendicular thereto, would appear as indicated in Fig. 2. Jets of electrolyte, entering through pairs of opposite entrance nozzles 4 and 5 (situated at the eadwalls 6 and 7 of co-roartment 28)' along the directions indicated by the horizontal arrows 1, 2, impinge against each other, and their kinetic energy is thereby dissipated into a swirling mo¬ tion, of which only a minor component contributes to an upward flow. The bed expansion and voidage can therefore be kept at an optimal low value while the fluidized particles maintain the rapid motions required for high rates of mass and charge transfer.According to an alternative embodiment of my invention, the view of section S-S of Fig. 1, perpendicular thereto, would appear as indicated in Fig. 3. Here the end walls 6 and 7 of corrmartmsnt 28 comprise vertical e- lectrolyte channels 8 and 9 separated from compartment 28 by filters 10 and 11. The latter also serve as flow distributors. During the first portion of a cycle, the electrolyte flews from channel 8 through filter 10 into compartment 28, and thence through filter 11 into channel 9, as in¬ dicated by arrows 12, 13. 3 the second portion of the cycle, the flew is reversed, as indicated by-the arrows 14, 15. Although -the flow directions 12, 13 and 14, 15 are horizontal in Fig. 3, it is also possible to use a configuration in which the entire Fig. 3 is turned around by 90° so as to yield an approximate¬ ly vertical reciprocating upward and downward flow.The reversal of flow directions may be effected by a special reciprocating pump (not shown) or by a unidirectional pump 24 acting in conjunction with an electronically programmed solenoid valve 25, as shown in Fig. 4. In the first portion of a cycle, valve 25 keeps the solid lines 26 and 27 open and the dotted lines 29 and 30 closed, thereby causing the flow through compartment 28 to be from right to left. In the second portion of the cycle, the links 26 and 27 are shut while lines 29 and 30 are opened, whereby the flow through com¬ partment 28 is reversed.Although the embodiments described herein are concerned prima- rily with fluidized air-depolarized cathodes, the improvements dis¬ closed herein are obviously applicable to numerous other types of e- lectrochemical reactors utilizing fluidized-bed electrodes, as is well known in the art.There will new be obvious to those skilled in the art many mo- difications and variations of the above-disclosed embodiments, which, however, will fall within the scope of my invention if defined by the following | CIAIMS :1. Apparatus cαπprising a fluidized-bed electrode, and means for in¬ creasing the kinetic energy of the fluidized particles in said elec¬ trode without seriously affecting the average bed expansion or voidage.2. The apparatus of claim 1 wherein said means comprises pairs of op¬ posing jets of fluid impinging against each other and thereby impart¬ ing swirling motions to the particles of the fluidized bed.3. The apparatus of claim 1 wherein said means comprises a reciproca¬ ting flow system causing electrolyte to flow through said electrode in a to and fro motion with reversals in the direction of electrolyte flow occurring at frequent intervals in repeating cycles.4. Apparatus of claim 1 wherein said fluidized particles comprise ac¬ tivated carbon.5. Apparatus as claimed in claim 1, wherein aid fluidized-bed elec¬ trode is an air-depolarized cathode.6. A method of increasing the curirent-carrying capacity of a fluidized- bed electrode which comprises increasing the kinetic energy of the flu¬ idized particles in said electrode without seriously affecting the av¬ erage bed expansion or bed voidage.7. The method of claim S wherein said kinetic energy is increased by causing opposing jets of fluid to impinge against each other so as to impart swirling motions to the particles of the fluidized bed.8. The method of claim 6 wherein said kinetic energy is increased by effecting a reciprocating flew of electrolyte through said electrode, with the direction of said flow reversing at frequent intervals in re¬ peating cycles.9. The method of claim 6 wherein said fluidized particles comprise activated carbon.10. The method of claim 6 wherein said electrode is an air-depolarized cathode. .OMPI | ZAROMB S | ZAROMB S |
WO-1979000337-A1 | 1,979,000,337 | WO | A1 | EN | 19,790,614 | 1,979 | 20,090,507 | new | H01H35 | null | F15B15, H01H35 | F15B 15/10, H01H 35/26D | BELLOWS-OPERATED DEVICES | Bellows-operated device wherein a pressure to be controlled is applied to the interior of the bellows (30) which operates indirectly a push rod (34) which in turn may operate an electrical switch. In order to render the device fail-safe, the bellows (30) is secured to a pressure pad (32) which contacts a flexible diaphragm (37) The bellows (30) is mounted in housing (35) which is sealed by the diaphragm (37) which has a larger effective area than the bellows. Leakage of the bellows into the space there-around increases the overall pressure on the diaphragm which therefore tends to operate the push rod (34) to simulate an increase in the pressure being controlled. | BELLOWS OPERATED DEVICES This invention relates to bellows-operated devices. Bellows are prone to failure, particularly by starting to leak through cracks or pin holes, and it is known, for instance in German Patent Application No. 2,125,809, to attempt to make the bellows fail- safe by placing another bellows around the working bellows. Such an arrangement, however, effectively doubles the possibility of failure because the exterior bellows may also develop a leak which will have the same effect as a leak from the working bellows.This invention provides a bellows-operated device including a bellows having a fluid pre-s-sure connection to its interior and at one end contacting directly or indirectly a flexible diaphragm, and a closed housing surrounding said bellows and sealed by said diaphragm, the effective area of said diaphragm being larger than that of the bellows. The diaphragm may be connected to operate another device, ft.g. an electrical switch, in such a way that in normal operation increased pressure in the bellows places the switch in an 'off or safe condition. Should the bellows leak into said closed housing the increase .in pressure in the housing acts on the larger effective area of the diaphragm and tends to place said switch in said 'off or safe condition. , In a- preferred arrangement the closed housing is subjected to atmospheric internal pressure, so that should the diaphragm leak there is no appreciable effect on the pressure in the housing. • Two specific embodiments of the invention are shown in the accompanying drawings, in which:- Figure 1 is,a section through a irst embodiment of a bellows-operated switch in a normal operating position, Figure 2 is a section through the -switch of Figure 1 in a failed position, Figure 3 i-s a section through a switch arrangement of a second embodiment, and Figure is a section through a bellows-operated device for xise in the embodiment of Figure >. Referring first to Figures 1 and 2, the switch as shown has a microswitch 11 the button of which is operated by one end of a pivotted lever 12. A coil spring 13 opposes upv/ard movement of the lever, which movement tends to open circuit the switch 11. A pre-ssure tapping 15 i-s connected to the interior of a metal bellows 16, which thereby expands and contracts as the sensed pressure varies. The bellows carries a pressure pad 17, which contacts a flexible diaphragm 18, e.g., a textile fabric reinforced synthetic rubber diaphragm or'a metal diaphragm. On the other side of the diaphragm is an operating member 19 comprising a chamfered disc part 20 which contacts the diaphragm and a button 21 which contacts a depression in the lever 12. Increasing pressure in bellows 16 moves the pressure pad and diaphragm upwardly which in turn pushes the operating member 19 upwardly and operates the switch 11 to open a circuit. The switch may therefore be used to maintain a pressure b-stween limits, the pressure being produced by means (not shown) powered through switch 11.Pressure tapping 15 forms one end of a housing 23 surrounding the bellows 16. The other end of the housing is closed by the diaphragm 18, the edges of which are clamped onto the housing. The diameter of the diaphragm is approximately twice that of the bellows. A space 2k is thereby formed about the bellows and this space is subject to a pressure below atmospheric by evacuation. This reduced pressure tends to pull the diaphragm 18 down substantially into the position shown in figure 1*, the bellows moving the diaphragm upwardly to open the switch as described above, against the resistance of the diaphragm.Should the bellows fail by beginning to leak, pressurized fluid will escape into space 2k. The degree of vacuum therein will therefore be reduced, the downward pull on the diaphragm will be reduced, until the diaphragm eventually moves up into the failed position shown in Figure 2. In this position the switch 11 is . permanently open circuit so that the apparatus to which it is connected cannot be operated. Should the diaphragm leak, air will leak into space 2k and again the diaphragm will move into the failed position. The embodiment of Figures 3 and k is similar to that of Figures 1 and 2, but shows the construction in more detail. Figure k shows the bellows operator part of the device, which Figure 3 shows the electrical switch part, the bellows part fitting onto the underside 5 of the switch part.Referring first to Figure k-. a metal bellows 30 has means 31 for attachment of a pre-ssure line so that the pressure is applied to the interior of the bellows. A pressure pad 3-2 is secured to the top of the bellows to move therewith and has a slightly rounded upper surface.-10 ' A flexible diaphragm 37 iβ moved'by said pressure pad so as to apply pressure to an operating button 33 secured to a push rod J>k. As shown in the drawing the bellows is mounted in a housing 35 which provides a T-section opening such that the effective diameter of the diaphragm is greater than that of the bellows, in this case of the order of 3 ∑ 1-15 The housing 35 provides a space 36 around the bellows and on one side of the diaphragm and in this embodiment this space is not evacuated but normally subject to atmospheric pressure.Since the interior of the bellows is subjected to greater than atmospheric pressure, any leakage of the bellows into space 36 increases20 the pressure on the underside of the diaphragm. Since the effective area of the diaphragm is greater than that of the bellows, the net effect is that the diaphragm is urged upwardly in the failed condition.When secured to the electrical switch part of Figure 3t the push rod contacts a cranked lever kO pivotted at kΛ which may be rotated25 upwardly against spring k2. Lever --+0 moves an adjustable actuator kj> which contacts the end of a rod kk which moves a member **+5 carrying electrical contacts 46, k7. Movement of push rod J>k therefore makes and breaks the contacts. The point of making and breaking the contacts may be adjusted by adjusting the position of pivot point kΛ by manual30 rotation of knob k8 which thereby effectively selects the pressure at which the switch contacts change over.. While the invention has been described above as applied to a pressure-sensitive switch, it could equally well be applied to other devices, e.g. , pressure-operated valves. The pressure applied to the35 interior of the bellows may as described be a direct bleed from a pressurized line or it may be related to a temperature sensed for instance by a phial positioned at a location of which the temperature is to be controlled. | CLAIMS:1. A bellows-operated device of the kind having a bellows (16,30) with a fluid pressure connection to its interior characterized by said bellows contacting directly or indirectly a flexible diaphragm (18, 37) and having a closed housing (23, 35) surrounding said bellows and sealed hy -said diaphragm, the -pressure-effective area of said diaphragm being greater than that of the bellows.2. A bellows-operated device as claimed in claim 1, further characterized by the effective diameter of the diaphragm (18, 37) being of the order of 2 to 3 times that of the bellows 06, 30).3- bellows-operated device as claimed in claim 1 or claim 2, further characterized by said housing being evacuated.k. A bellows-operated device as claimed in Claim 1 or .claim 2, further characterized by said housing (.35) providing a T-section interior space (36), the diaphragm extending across the top of the Ti and the bellows extending down the centre limb of the T.5- A bellows-operated device as claimed in any of claims 1 to , further characterized by said diaphragm operating directly or indirectly a push rod (21, 3k) extending into an electrical switch compartment to operate switch means (11, 46, 47) therein.PR393OM $ mP | UNITED GAS INDUSTRIES LTD; UNITED GAS IND LTD | MCGOWAN E |
WO-1979000343-A1 | 1,979,000,343 | WO | A1 | EN | 19,790,614 | 1,979 | 20,090,507 | new | C22C19 | C22C19, C22C38 | C22C19, C22C38 | C22C 19/00, C22C 19/07, C22C 38/60 | IMPROVEMENTS IN OR RELATING TO NICKEL-,COBALT-,AND IRON BASED ALLOYS | The oxidation resistance and corrosion resistance of a nickel-, cobalt- or iron-based alloy can be improved by including in the alloy composition a platinum group metal, viz. osmium, iridium, platinum, ruthenium, rhodium, or palladium, and one or more platinum-complementing elements, viz. titanium, scandium, yttrium, lanthanum, hafnium, tantalum, zirconium, niobium and any of the lanthanide elements in balanced proportions. The resultant alloy composition consists of at least 5 weight percent of chromium, from 0 to 3 weight percent of carbon a component X, a component Z, and a balance of one or more of nickel, cobalt and iron together with incidental elements and impurities if any, wherein component X is one or more of (i) at least 2 weight percent in total of one or more of aluminium, titanium, tantalum and niobum; (ii) at least 5 weight percent in total of one or both of tungsten and molybdenum, and (iii) at least 60 weight percent of nickel, and component Z comprises m<up>u weight percent of one or more platinum group metals together with m<uc>u weight percent of one or more platinum-complementing metals with 0.1 </= m<up>u + m<uc>u </= 5 and 0.3 </= m<up>u/m<uc>u </= 20. The amount m<up>u of the platinum group metal is preferably from 50 to 95 percent by weight of the total (m<up>u + m<uc>u), and most particularly the amounts of the platinum group metal and the platinum-complementing metal are chosen to be in stoichiometric proportions with reference to intermetallic compounds which may be formed between them. The improved alloys are particularly suited to use for gas turbine engine components. | SItie: Nickel-, Cobalt- and Iron-based Alloys, 2his invention relates to nickel-, cobalt- and iron-based alloys comprising those suitable for use at high temperatures under oxidising conditions or corrosive conditions, and more particularly, but not exclusivelyj is concerned with directionslly solidified nickel-based alloys for use in these conditions.Alloys capable of resisting oxidation, corrosion &_\- high mechanical stresses at elevated temperatures are increasingly required, particularly in the gas turbine field. In these applications slight increases in permissible blade temperatures have a considerable and very favourable effect upon engine output and efficiency. It is an unfortunate characteristic of gas turbine alloy development, however, that changes in alloy composition which lead to improved high temperature strength tend also to reduce the oxidation resistance of the alloys. Many of the strongest gas turbine alloys presently known have a relatively low resistance to oxidation and corrosion, -~so that they must be protected against high temperature attack, ie corrosion and oxidation, by coatings which either remain on the surface of the alloy components or are caused to diffuse into the body of the components on which they are deposited. Is is a dis¬ advantage of the various coating processes employed that they are costly, and that they tend also to have a deleterious effect upon the high temperature mechanical properties of the components to which they are applied. 3his invention seeks to provide high temperature nickel, cobalt and iron-based alloys having oxidation and corrosion resistance made good by controlled alloying additions which do not have any substantial adverse effect on the high temperature mechanical strengtii of the alleys in which they are incorporated and which, at least in some cases, lead to enhanced oxide scale adhesion.According to a first aspect of the present invention there is provided on alloy consisting of at least wt % of chromium, from 0 to 3 wt of carbon, a component X, a component Z, and a balance of one or more of nickel, cobalt and iron together with incidental elements and impurities if any, wherein component X is one or more of;(i) at least 2 wt # in total of one or more of aluminium, titanium, tantalum and niobium, (ii) at least 5 wt % in total of one or both of tungsten and molybdenum, and(iii) at least 60 wt of nickel; and component Z comprises m wt % of one or more platinum group metals (as herein defined) together with mc wt of one or more platinum-complementing metals (as herein defined) with0.1 ^ a + ~~^^ 5 and0-3 z__Z p / mΛc^- 20According to a second aspect of the present invention there is provided a method of modifying the oxidation resistance and corrosion resistance of a nickel based, cobalt based or iron based alloy, which comprises including in the alloy composition an amount m wt of a platinum group metal (as herein defined) together with an amount m wt % of one or more platinum comple- c menting elements (as herein defined), and wherein with percentages being relative to the alloy composition which is the product of the method. _,'v- WIPO In this specification, the expression platinum group metal should be taken to mean one of osmium, iridium, platinum, ruthenium, rhodium and palladium, and the expression 'platinum-complementing element should be taken to mean one of the following:- titanium, scandium, yttrium, lanthanum, hafnium, tantalum, zirconium, niobium, and any of the lanthanide elements (Ce to u). Incidental elements and impurities can comprise elements such as silicon, manganese and boron or, to a lesser extent vanadium, which elements are usually found in commercial iron-based alloys, and will also generally comprise small amounts of oxygen, nitrogen, hydrogen, phosphorus and sulphur. Nickel-, cobalt- and iron-based gas turbine alloys depend for their high temperature strength on carefully controlled micro-structures which generally contain, among several other phases, carbides based on K.(Mo)C, !K.(Eb)C or other transition element compounds. Otherwise, the micro-structures may contain less stable components, such as Cr-C . (It has been proposed to provide C ^C- in a directionally solidified alloy in the form of slender reinforcing fibres). If these strengthening carbides are to retain their integrity and reinforcing ability at high temperatures, the matrix of the alloy must have a low affinity either for carbon or for the metal from which the carbide is formed. Certain metals known for their solution strengthening capabilities have a high affinity for one or the other of the components of these strengthening carbides. Bieir addition has been shown to render the rein¬ forcing carbides less stable. Ems zirconium, for example, which strengthens solid solutions very effectively in other alloy systems, cannot, in general, be added safely to superallojs because of its.,very high affinity for carbon, which tends to decompose any titanium or niobium carbides in its vicinity. It is well known that reactive metals such as Y and La, when present in suitable concentrations, can improve the high temperature oxidation and corrosion resistance of nickel-, cobalt- and iron-based alloys. However, these elements have, like zirconium, a high affinity for carbon, tvlien they are present above a critical concentration level they have a tendency to attack the reinforcing constituents of the alloy in which they are incorporated. For example, consider a Ni-Ni-Al-Cr-C directionally solidified eutectic alloy which depends for its high temperature strength upon fine longitudinal fibres of Cr_C , ϋhe Applicants have found that rare earth metals such as yttrium, when present in excess in the alloy, tend to decompose these reinforcing fibres, thus limiting the high temperature mechanical properties of this material, although its oxidation resistance is improved..Relatively small additions of one of the six platinum group metals (Os, Ir, Pt, Ru, Ki, Pd) are known by the present resistn ,c° Applicants to enhance the oxidation and corrosion/oi specific nickel-, iron- and cobalt-based alloys, particularly when the alloy to which additions are made is one of those which form a protective layer of aluminium oxide. Substantial additions of platinum group metals can rarely be made to such materials, however, because these metals have a tendency to decompose any carbides upon which the superalloy depends for mechanical reinforcement. This decomposition is caused, not because of the affinity of the platinum metals for carbon, which is very small, but because of their exceedingly high affinity for the metals which form stable carbides. Itis known, for example, that platinum and iridium are capable of decomposing lanthanum carbide at temperatures as low as 1000 C. When platinum additions are made, therefore, to the directionally solidifiedNi-Ki_Al-Cr,C_ eutectic composite mentioned above, the alignedCr-Cp reinforcing fibres are partly decomposed and carbon isOMPI ' 5 released in the form of graphite flakes. Biis leads to a deterioration in mechanical properties.Considerations such as those outlined above appear there¬ fore, at first glance, to preclude the use of the strongly 5 carbide-forming elements and of the carbide-decomposing elements as beneficial additions to existing high temperature nickel-, cobalt- and iron-based alloys.It has been found that, in accordance with the present invention, the above-mentioned carbide-forming and carbide-10 decomposing groups of metals can in certain circumstances be jointly added to εuperalloys in quantities up to a total of 5% by weight without any deleterious effect upon structure or mechanical properties, and with some improvement in their resistance to oxidation and corrosion at high temperatures.15 It is thought that this is possible because the platinum group (carbide-decomposing) metals have an affinity for the carbide- orming elements which is comparable to and in most instances higher than the affinity of these carbide-forming elements for carbon. The strengthening carbides can thus remain20 stable, and the platinum group metals can therefore be safely added without detriment to the high temperature properties of nickel, cobalt- or iron-based alloys, provided that they are suitably associated with one or more of the platinum complement- - ing elements titanium, scandium, yttrium, lanthanum, hafnium,257 tantalum, zirconium, niobium and any of the lanthanide elements-N (Ce to u).While the most beneficial effects are obtained when the composition of the component Z is stoichiometrically adjusted to provide for example the compounds listed below in ϊfeble 1,30 precise adjustment is not essential, and preferably component Z contains between 50 and about 93# b weight of the platinum group metals. In any case, there must be more than about 0.025 wt % of a platinum group metal present in component Z (corres¬ ponding to a lower limit of 0.3 in the quantity ra » given a3-5 lower limit of 0.1 in the σ tuantity (mp + mc). c TABLE IOMPl uhe present invention will now be illustrated by the followingExamples:-EXAMPLE 1 3b an alloy having a nominal composition (expressed in wt #) as set out below (incidental elements and impurities amounting to 1 wt #) various additions were made to give alloys A, B, C and D as shown in ϋ ble 2.TABLE 2 8Alloys C and D are according to the invention. Ihe basic alloy and alloys A and B are for comparison.3-he observations set out below were made on the ive alloy compositions given in .Cable 2. Kiσrostructure.Directional solidification of the basic alloy at a rate of 30Qnii--/hour in a temperature gradient of about 13°K m~ produced an ingot in which were present Cr- fibres well aligned within a gamma nickel matrix which contained equi-axed particles of gamma prime (Ni_Al). The alloys A and D contained yttrium in excess of that required for the formation of Pt_Y and, in addition to the phases mentioned above, these two alloys also exhibited an elongated eutectic-like constituent which tended to run parallel to the aligned carbide fibres. ϊhis irregular constituent is thought to contain an yttrium-carbon compound.Die alloy to which 1.96$ by weight of platinum(alloy B) had been added contained a quite different irregular phase. -Biis phase is thought to be pure graphite deposited due to the release of carbon on the formation of a highly stable platinum-chromium compound. {No additional phases or micro constituents were observed in the alloy to which the platinum and yttrium in the ratio needed to form the compound PtςY (alloy C) had been added. (If the compound PtςY retained its separate identity when added to the alloy it must, presumably, have been in the form of a dispersion too fine to resolve with the optical microscope). Ihe alloy displayed a regular aligned eutectic structure with thin fibres of Cr,C supported in a matrix consisting of nickel containing finely distributed particles of the compound Ni_Al. Oxidation Resistance.She basic alloy to which no addition had been made had a relatively poor resistance to oxidation when exposed to air at high temperatures either cyclically or under isothermal conditionsO ϊhe initially formed scale of A1 3., εpalle-d readily and oxida¬ tion continued with the formation of Cr,,0_, nickel-chromium e- 3 spinels, and with internal oxidation. he addition of yttrium alone (alloy A) improved the oxidation resistance significantly by stabilising the layer ofAl-,0- which formed initially. Even so, the A1_0_ scale which . 5 <_ $ formed was not completely tenacious, and cpalling occurred under tests carried out in a high velocity gas stream approxi¬ mating in composition and speed to the hot gas passing over the first stage blading in a gas turbine, when the alumina scale was removed as rapidly as it was formed leaving behind the more tenacious skin of nickel-chromium oxide. ϊhe alloy to which the εtoichio etrically adjusted Pt_Y addition has been made (alloy C) developed on oxidation testing in air a protective skin of alumina which was resistant to spa-i.li.ng when cycled in temperature and also when handled at room temperature. After exposure to air at atmospheric pressure for 1000 hours at 1000°C no measurable oxide skin was observed and the carbide fibres retained their integrity to the specimen surface.Hot salt corrosion resistanceSpecimens (in the form of cylinders 6mm dia x kh mm) of alloys A and C and of the basic alloy were tested in a gas burner rig in conditions of hot salt corrosion at a temperature of 850 C. A commercial superalloy designated IN 713 kO was also tested for purposes of comparison. Two specimens of each alloy were tested, ϋhe principal impurities in the fuel used in the burner were 0.15pp∑n sulphur and 50ppm sodium, the latter being introduced in the form of sodium carboxylite. In addition 50 aι of sodium chloride was injected into the air feed in the form of sea water, he specimens were removed and examined at 2k hr intervals and the tests were run for a total of 300 hrs. 10 At the end of the tests all the alloys showed distint evidence of attack although all of the eutectic-baεed alloys retained a more regular cylindrical shape than the IN 713 LC spec¬ imens, ϊhe latter was subject to internal attack along grain boundaries giving both more rapid and irregular corrosion than with the former which degraded by regular surface attack, ϊhe depths of penetration of the corrosion products, determined from transverse sections of the specimens are given in Table 3 below, from which it will be seen that the most corrosion resistant alloys are the basic (eutectic) alloy and the alloy C according to the invention.TABLE 3Creep BehaviourTable 2 above shows the results of creep tests performed in air on the various alloys at 1000 C under a direct tensile stress of lOOmPa. ϊhe alloy C retained the mechanical properties of the yttrium doped alloy (alloy A) and both were substantially stronger containing ° at high temperatures than those/either Pt or Y (alloys B and D respectively) above the level required to form stoichiometric ~~ X.OMP• IP 11 EXAMPLE 2 3-he nominal compositions of the alloys studied are shown in Table 3« Alloy K is according to the invention and the remaining alloys are for comparison.TABLE ?Alloy Cr Al Pt Wt t %J 10 11 1 - )K 10 11 0.9 0.3)L 10 11 - - )H 10 11 - 1 )N 10 11 - 0.3) balance cobaltOxidation experiments were carried out in static air at 1 sphere pressure in a horizontal tube furnace, ϋheraogravi- metric measurements were performed in a Sartorius automatic recording raicrobalance at 1100 C. Eeεults are as set out below and as shown in Table k. Alloy MicrostructureNo microstructual differences between alloys J and L were observed. In alloy J, neither electron probe micro-analysis or optical examination were able to detect any intennetallics containing platinum. Alloy K (containing 0.3 Hf - 0.9 Pt) had a grain size smaller than alloy L and similar to that in Hf- containing alloys with no platinum (alloys M and N). Again, no platinum-containing intermetallics could be detected in alloy K and it would appear that the hafnium and platinum additions were both completely soluble in the alloy, at least at the concentrations used here. On oxidation of the samples of alloy , the hafnium usually oxidised internally, but there was no apparent segregation of the platinum. 12Oxidation Kinetics.Figures 1 and 2 of the accompanying drawings show the effect of Pt and Pt + Hf additions on the rate of weight gain of the basic Co-lOCr-llAl alloy L under isothermal oxidising conditions at 1100°C. Figure 1 shows that the addition of 1 #?t (alloy J) results in a slight decrease in the isothermal oxida¬ tion rate. Figure 2 is a plot of wt gain versus time each on a logarithmic scale. When measured over the period 10 to 100 h to avoid the initial transient stages of oxidation, the slope of the curve for alloy L has a value of 0.51 corresponding almost exactly to a parabolic rate law. 33ιe slope is reduced to 0.4 for the Co-lOCr-llAl-lPt alloy J. .For the alloys containing 0.3 wt Hf (alloys and N) the situation was rather different. Neither conformed to a parabolic rate law, the Co-10Cr-llAl-0.3Hf alloy N had a slope of 0.28 whilst for the alloy containing 0.9 P (alloy K) the elope was O.lδ. I addition, Figure 1 shows that the initial stages of oxidation of alloy K were terminated more rapidly than in alloy N, and that with both these Hf-containing alloys the transient stage was shorter than with the Hf-free alloys J and L. As indicated previously, it is difficult to define precisely the end of the transient stage, but typically it lasted for • -! h. Table h compares the weight gains of the four alloys after this period (1 h) and after 120 h exposure. Also included for comparison are the data for an alloy K known to the Applicants to have a particularly low overall weight gain under these conditions. Biis alloy R is Co-10Cr-llAl-0.3Hf internally oxidized for 300 h at 1200°C.OMΛ,- WIP 13 TABLE kWeight Gain Data at 1100 C ; Isothermal ExposureWeight GainAlloy mg cm1 h 120 hL *. Co-lOCr-llAl 0.15 0.9 5 J : Co-lOCr-llAl-lPt 0.16 0.72N : Co-10Cr-llAl-0.3Hf 0.2 0.53 K : Co-10Cr-llAl-0.3Hf-0.9Pt 0.1 0.2 R : Co-10Cr-llAl-0.3Hf 0.09 0.18 (internally oxidized 0 300 h at 1200°C).Scale MorphologyShe A1„0, scale which formed on the alloy Co-lOCr-llAl-lPt^ o(alloy J) after 265 h oxidation at 1200 C was not adherent and spalled from the alloy on cooling, ϊhe oxide was multi-layered 5 in many locations, particularly at the corners of the sample, and the outer layer of oxide at the gas/scale interface was heavily wrinkled. Similar features were observed with the ternary Co-Cr-Al alloy (alloy L) oxidized tinder similar conditions. 0 - Surface examinations of the alloy Co-lOC-r-llAl-O.3Hf-O.9pt ...' alloy K) after oxidation at 1200°C revealed features similar to• s those of the alloy Co-10Cr-llAl-0.3Hf (alloy N). ϊhe A1«0, scale was tightly adherent to the substrate and spalled during cooling only from small discrete areas, ϊhe major difference 5 between the two alloys was that, with the Pt-free alloy N, the substrate surface appeared to be more heavily convoluted than with the Pt-containing alloy K.-gUREATTOMPI | uWHAT WE CLAM IS:1. An alloy consisting of at least 5 weight percent of chromium, from 0 to 3 weight percent of carbon, a component X, a component Z, and a balance of one or more of nickel, cobalt and iron together5 with incidental elements and impurities if any, wherein componentX is one or more of:(i) at least 2 weight percent in total of one or more of aluminium, titanium, tantalum and niobium;(ii) at least 5 weight percent in total of one or both10 of tungsten and molybdenum; and(iii) at least 60 weight percent of nickel; and component Z comprises m weight percent of one or more platinum group metals (as herein defined) together with ra weight c percent of one or more platinum - complementing metals (as herein 15 defined), where0.1--^^ mp + rac <^-» 5 and 0.3 ^^ mp/*mc ^-. 20 all the weight percentages being relative to the total weight of the alloy.2. An alloy according to claim 1, vherein component Z contains 20 from 50 to 95 by weight of one or more platinum group metals.3. An alloy according to claim 2, wherein component Z contains substantially stoichiometric quantities of a platinum group metal and a platinum - complementing metal corresponding to the composition of a compound of the metals.25 . An alloy according to any of claims 1 to 3» wherein component X comprises at least6θweight percent of nickel. 5. An alloy according to any of claims 1 to 3, wherein component X comprises at least 5 weight percent in total of one or both of tungsten and molybdenum. 156. An alloy according to any of claims 1 to 3, wherein component X comprises at least 2 weight percent in total of one or more of aluminium, titanium, tantalum and niobium.7. A method of modifying the oxidation resistance and corrosion resistance of a nickel-based, cobalt-based or iron-based alloy, which comprises including in the alloy composition an amount m weight percent of a platinum group metal (as herein defined) together with an amount ra weight percent of one or more platinum c complementing elements (as herein defined), and wherein 0.1 π + m <r 5 with percentages being relative to the alloy composition which is the product of the method.8. A method according to claim 8, wherein m comprises from 0 to 9 $ of the total additive ( + m ). p c 9.. A method according to claim 9 wherein a platinum group metal and a platinum complementing metal are added in stoichiometric quantities corresponding to the composition of a compound of the metals./KC LOO | DARLING A; MCLEAN M; SECR DEFENCE; SECRETARY STATE FOR DEFENCE | DARLING A; MCLEAN M |
WO-1979000351-A1 | 1,979,000,351 | WO | A1 | XX | 19,790,628 | 1,979 | 20,090,507 | new | H04J3 | null | G08C15, H04J3, H04L7, H04Q9 | G08C 15/12, H04J 3/06C1, T04L 7/00B | CONTROL SYSTEM USING TIME DIVISION MULTIPLEXING | A control system for selectively communicating a plurality of sensors (17) with associated remote control devices (19, 20) includes a Master Synchronizer (10), a transmitter (11, 12) for each sensor and a receiver (13 14a) for each control device. A single signal line (14) is connected to all transmitters (11, 12) and receivers (13, 14a), and a single synchronization line (15) couples the Master Synchronizer (10) to all transmitters and receivers. The Master Synchronizer (10) generates a time frame signal which has a reset portion for resetting all transmitters and receivers synchronously at the start of each frame, and a periodic portion which determines the time slots for each frame and which decrements counters (31, 38) in all transmitters and receivers synchronously. A time division multiplex system is used to communicate each transmitter with one or more associated receivers during a predetermined time slot of a periodic time frame determined by the Master Synchronizer. | CONTROL SYSTEM USING TIME DIVISION MULTIPLEXING BACKGROUND AND SUMMARYThe present invention relates to control systems; and more particularly, it relates to control systems wherein a number of individual sensors (a thermostat, for example) are used, and it is desired to selectively communicate each sensor with one or more control devices associated with that sensor. Control systems of this type may be used, for example, in large buildings where it may be desired to integrate all of the heating, ventilating, cooling, and even secto ity systems into a single master system.The present invention includes a transmitter for each sensor, a receiver for each control device and a Master Syncronizer. A single signal line is connected to all trans¬ mitters and receivers; and a single synchronization line couples the Master Synchronizer to all transmitters and re¬ ceivers. The Master Synchronizer determines the overall time frame or operating cycle of the system, and the signal it transmits includes a periodic signal portion and a reset signal portion. Each cycle of the periodic signal defines a time slot in the time frame, and the reset signal portion is used to reset the Master Synchronizer and all transmitters and receivers at the same time, thereby achieving overall synchronization. Each transmitter and one or more associated receivers are allocated a predetermined time slot of the time frame, during which time slot the transmitters communicate with their associated receivers.A decrementing counter is provided for each trans¬ mitter and each receiver. At the beginning of each frame, these counters are set to a predetermined number representa¬ tive of the time slot allocated to those units. When the counter is decremented to zero, a time slot is defined for communicating a transmitter with its associated receivers. Thus, a transmitter is permitted to send a signal along the signal line to all receivers associated with it, and this signal causes a response only in those receivers whose counters have been decremented to zero during the same time slot. In the preferred implementation, this communica¬ tion occurs once every time frame.The Master Synchronizer also includes a decrementing counter, and when it reaches zero the transmission of syn¬ chronization ( sync for short) signals to all transmitters and receivers is inhibited for a predetermined time. Thus, the absence of sync pulses is used as a reset signal to reset the Master Synchronizer and all transmitters and receivers once each time frame. An energy-containing signal, rather than the absence of a signal, is required to actuate a control device. This reduces error in the event of line interruption or power failure.THE DRAWINGFIG. 1 is a functional block diagram of a system incorporating the present invention;FIG. 2 is a circuit schematic diagram, partly in functional block form, of a Master Synchronizer used in the system of FIG. 1;FIG. 3 is a circuit schematic diagram, partly in functional block form, of a transmitter in the system of FIG. 1;FIG. 4 is a schematic diagram of circuitry which interfaces a control input with the transmitter of FIG. 3;FIG. 5 is a circuit schematic diagram, partly in functional block form, of a receiver for actuating a control device in accordance with FIG, 1; andFIG. 6 is a timing diagram illustrating various operating waveforms in the system,DETAILED DESCRIPTIONReferring first to FIG. 1, the system includes a Master Synchronizer which is enclosed within the dashed line 10, a plurality of transmitters, two of which are shown and enclosed within the dashed lines 11, 12, and a plurality of receivers, two of which are shown and enclosed within the dashed lines 13, 14 respectively. Persons skilled in the art will appreciate that the system is not limited to any particular number of transmitters or re¬ ceivers, and that the number of transmitters may be differentξ* * tA~0,' PI than the number of receivers, A signal line 14 is connected to all of the transmitters and receivers; and a sync line 15 is connected to the Master Synchronizer 10 and all of the transmitters and receivers.As will be more fully explained below, the Master Synchronizer 10 generates a synchronization and timing sig¬ nal which is coupled to all of the transmitters and all of the receivers. This synchronization and timing signal in¬ cludes a reset portion and a periodic portion, both of which form a complete cycle or frame . The reset signal portion of the signal is used to reset the Master Synchronizer and all transmitters and receivers at the beginning of each frame; and the periodic portion of the signal is used to define time slots within the frame. Each transmitter and its associated receiver or receivers is assigned or allocated a particular time slot during which time that transmitter communicates with all of its associated receivers via signal line 14. For example, the Master Synchronizer may define 256 time slots each frame, and by convention, these are numbered 0 through 255. The last time slot, namely 255, is reserved for system protection and utilization by the Master Synchronizer for frame detection. Supposing, then, that transmitter 11 in FIG. 1 is assigned time slot 0, then during that time slot it would communicate with as many receivers as may be desired by means of an information signal transmitted along the signal line 14. This transmitter and all of its associated receivers obtain common timing information from the sync line 15. Another transmitter and its associated receiver or receivers may be assigned time slot 1, and so on, up to transmitter No. M designated 12 in FIG. 1. Each of the transmitters has associated with it a sensor device, and these are designated 17 and 18 in FIG. 1 respectively for the transmitters 11, 12. Further, each of the receivers is connected to a control device, and these are designated 19 and 20 respectively for the receivers 13, 14.Each of the transmitters is similar in structure and operation, as is each of the receivers. The only dif¬ ference in transmitters is the information or signals stored__Oi\\Pl - wip to identify its time slot, and the same is true for receivers, hus , a complete understanding of the invention can be ob¬ tained from a description of only one transmitter and one receiver.Still referring to FIG. 1, the Master Synchronizer includes a master encoder22 having a plurality of binary - outputs defining the number of time slots in a frame. These outputs are connected In parallel to the inputs of a decre¬ menting counter 23. A master oscillator 24 generates a periodic signal coupled through a line driver circuit 29 to the sync line 15. The sync signal is received (after suit¬ able filtering) by a clock flip flop 25 and a reset timer 28. The clock flip flop 25 divides the frequency by two and generates a signal labeled CLK on line 26 to decrement the counter 23. The output of the reset timer is used to load the contents of the master encoder 22 into the counter 23 at the beginning of each time frame. Briefly, the Master Synchronizer operates as follows. The output of the master oscillator 24 is coupled to the flip flop 25 (via the sync line) which is used as a divide by two circuit to decre¬ ment the counter 23. When the contents of the counter 23 is decremented to zero, an output signal from the counter is used to inhibit the master oscillator 24 from producing further timing pulses . The absence of timing pulses on the sync line over a predetermined period is sensed by the reset timer 28, and at the end of that predetermined period, it generates a signal which loads the contents of the master encoder into the counter 23. thus releasing the master oscillator and initiating a new frame.Turning now to the transmitter 11, it includes an encoder 30, having its ouptuts connected in parallel to the Inputs of a decrementing counter 31. The signal from the sync line 15 is coupled to the clock input of a CLK flip flop 32 and to a reset timer 33. Persons skilled in the art will appreciate that suitable filtering, well known in the art, may be used at all locations where signals are derived from either the signal line 14 or the sync line 15. The 1 output of the flip flop 32 is used to decrement the counter 31; and complementary outputs from the flip flop 32 are connected to gate circuits 34. The output of the reset timer 33 is used to load the contents of the encoder 30 into the counter 31 at the beginning of each frame. The output of sensor 17 is connected to the gate circuits 34, and the output of the gate circuits is coupled through a line driver 35 to the signal line 14.Briefly, the transmitter operates as follows. The sensor 17 generates a binary signal—that is, the output of the sensor 17 is in one of two states. In its more general aspects, however, the invention is not limited to the use of binary sensors, but most sensors in commercial use for which the invention is presently intended fit this category. The output signal of the sensor 17 (in complementary form) is fed to the gate circuits 34 and is present at all times. The absence of pulses on the sync line 15 defines the reset signal portion of the sync signal; and the reset timer 33 detects this reset signal portion of the sync signal, and loads the contents of the encoder 30 into the counter 31. The contents of the encoder 30, as mentioned above, is a ' binary word representative of the time slot allocated to transmitter No. 1. After the counter 31 is loaded and sync pulses are transmitted on the sync line 15, the CLK flip flop 32 decrements the counter 31. When the counter 31 reaches a count of zero, an enable signal is fed to the gate circuits 34. The output of the flip flop 32 is combined in the gate circuits 34 with the output of the sensor 17 and enabled by the output of the counter 31 to transmit an ON signal during the CLK (true) period and an OFF signal during the CLK (not) period. In this manner, a failure that would cause the sensor signal to be high during both CLK and CLK period- will result in an OFF signal to the load or control device. In other words, ambiguous signals result in an off condition at the control device. Further, the absence of a signal during both the CLK and CLK periods does not affect the existing state of the control device--if it is on, it stays on; and if it is off, it stays off. Referring now to the receiver 13, it Includes an encoder 37 similar to the previously described encoders 22 and 30, and having a plurality of outputs connected in par¬ allel to the inputs of a decrementing counter 38. The coun¬ ter 38 generates a signal when its contents is decremented to zero, and this signal is fed to the inputs of gates 39, 40, the outputs of which feed respectively the JK inputs of a flip flop 41. The output of the flip flop 41 is used to activate the control device 19. The receiver 31 includes a reset timer 42 which is responsive to the reset signal por¬ tion of the sync signal for loading the contents of the encoder into the counter 38. The receiver also includes a CLK flip flop 43 which is responsive to the periodic signal portion of the sync signal for decrementing the counter 38 and for feeding a strobe signal generator 45. The comple¬ mentary outputs of the flip flop 43 are also fed to the gates 39, 40 respectively, as illustrated.The receiver operates as follows . The reset timer 42 is responsive to the reset signal portion of the sync signal for loading the contents of the encoder 37 into the counter 38. Thereafter, the periodic portion of the sync signal is fed to the flip flop 43 to decrement the counter 38. When the counter 38 is decremented to zero, it sends an enable signal to the gates 39, 40. The actuation signal on the signal line 14 is also coupled to the gates 39, 40, and at the appropriate time (determined by strobe generator 45) during the time slot allocated to Receiver No. 1, the signal on line 14 is gated through the gates 39, 40 to the flip flop 41 from which it is used to activate the control device 19. The strobe signal is derived by delaying the sync signal, as will be explained. As a result, If both inputs to flip flop 41 are low at strobe time, its output remains unchanged. If gate 39 is enabled at strobe time, flip flop 41 is set; and if gate 40 is enabled at strobe time, flip flop 41 is reset. The control device 19 is controlled accordingly.The counters of the Master Synchronizer and all transmitters and receivers are reset at the beginning ofOΛ-PIA -. VV1JPPOO each time frame; and in the preferred embodiment, this is accomplished by sensing the absence of periodic synchroniza¬ tion signals. If it is desired to have the control device 19 actuated by sensor 17, then the contents of encoder 30 and the contents of encoder 37 are made identical. The con¬ tents of these two encoders may be established by direct wiring, the use of manually controlled switches, semiconduc¬ tor switches, or any number of other techniques. It will also be appreciated that any number of receivers may be allotted to the same time slot and thereby controlled by the same sensor. One advantage of the present invention is that a given receiver may be assigned to a different transmitter simply by changing the contents of its encoder. Conversely, a given transmitter may be assigned to a different receiver in the same manner.Referring now to FIG. 2, the master oscillator includes a comparator 50 having its output connected to the clock (C) input of a flip flop 51. A 5 kHz sync signal is fed through a filter section 55.The discharge path of a capacitor 61 includes a resistor 59 since the diode 63 is reversed-biased. Hence, the charging time of the capacitor 61 is much shorter than its discharge time. The output of the comparator 62 is a signal referred to as JAM; and this signal is coupled to the counter 23 to load the contents of the master encoder 22.The signal INIT is used to hold the counter 23 and the oscillator 24 for an initial period of time (tl on line L7 of FIG. 1) until the power supply levels have sta¬ bilized. When the signal INIT goes low, the signal OSCN also goes low and the signal OSCP goes high. The oscillator 24 will not commence oscillation for a second time delay identified as time T2 in line L2 of FIG. 6. The output signal from the counter 23 which is fed to the NAND gate 73 is generated when the counter is decremented to zero and it is a low signal which changes the states of OSCN and OSCP, thereby terminating operation of the oscillator 50 when the counter 23 is decremented to zero. The number of time slots in a given frame is deter¬ mined by the master encoder 22. In the event that the master encoder 22 is inoperative, resistor 79 will force the coun¬ ter to the maximum count of 256, and the system will still operate.The signal OSCN is used to reset the flip flop 51, and It is also coupled through a delay circuit comprising resistor 76 and capacitor 77 which determine delay time T2 of line L2 of FIG. 6 (as well as the frequency of oscilla¬ tion) , to the oscillator 50 to commence oscillation. The signal on line L3 of FIG. 6 is the shaped sync signal at the output of comparator 58. Flip flop 25 ignores the first clock signal and it is held with the CLK output high because the JAM signal causes it to remain in the set condition. The JAM signal is therefore released as shown in line L4 of FIG. 6 after a time constant T4 defined by the values of resistor 60 and capacitor 61. The JAM signal will remain low as long as incoming pulses are received to charge capa¬ citor 61 at a rate faster than charge leaks off the-- capaci¬ tor. This will cause the plus input of comparator 62 to remain higher than the V-n fed to the negative input. The resulting JAM signal, when it occurs as indicated in line L4, causes the counter 23 to be loaded with the contents of the master encoder 22.With the JAM signal thus released after the first positive excursion of the output of the comparator 58, the flip flop 25 will respond to subsequent positive-going lead¬ ing edges to generate the CLK signal seen in line L5 of FIG. 6. The CLK signal thus corresponds to the sync signal counted down by a factor of 2. The CLK signal from the flip flop 25 is, as mentioned, coupled via line 26 to decrement the counter 23. When counter 23 Is decremented to zero, the signal DECODE goes low. This signal, inverted, is shown on line L12 of FIG. 6; and when it goes low, it changes the output state of gate 73, thereby changing the states of signals OSCN and OSCP. This action terminates operation of the oscillator 50 and immediately resets the flip flop 51, thereby causing the 5 kHz sync signal to go negative as indicated at 86 on line L2. Then the signal JAM will go low, to re-load the contents of the master encoder 22 into the counter 23. This longer delay is defined as time constant T5 in FIG. 6. At the same time, the output of the gate 66, namely the signal JAM inhibits operation of the flip flop 25 for the first cycle of the next frame. The JAM signal sets the CLK flip flop in transmitters and receivers, as well, for these reasons: (a) if the CLK is falsely triggered, the JAM signal brings it back into synchronism with the rest of the system on the next frame; (b) to insure that the CLK flip flop is in a known state when power is turned on; and (c) the first sync pulse derives the strobe for CLK true DECODE 0 to protect against ambiguities that would occur if the transmitted signal remained high.Turning now to FIG. 3, the transmitter is similar in operation to the master encoder just described in many of its aspects.. The absence of sync pulses permits capacitor 112 to discharge, and after a predetermined time, the JAM signal will go low, thereby loading the contents of the encoder 90 into the counter 91. The signal CLK is used to decrement the counter 91 after it is loaded with the contents of en¬ coder 90; and when the counter 91 is decremented to zero, it generates the signal DECODE, and this signal is used to generate an enable signal to the gates 95, 96. 'If the sig¬ nal SWON is positive, then the one output of flip flop 98 is positive and during the positive half cycle of CLK, the gate 95 will generate a pulse such as the one shown (inver¬ ted) on line L7 of FIG. 6 during the first half cycle of the CLK signal during the time slot associated with that parti¬ cular transmitter. If the output of the sensor is a zero or low signal, then the zero output of the flip flop 98 is high. During the next cycle of the signal CLK,the gate 96 will generate a pulse such as the one shown (also inverted) on line L8 of FIG. 6.FIG. 4 shows a circuit schematic diagram for the logic power supply. Turning now to FIG. 5, the receiver receives the 5 kHz sync signal from the sync line 15. The output of com¬ parator 156 comprises the signal JAM for the transmitter.The delay circuit 159 delays the input to the com¬ parator such that the strobe signal occurs at approximately the 40% point of the CLK and CLK periods, see line L9 of FIG. 6. This timing may be compared with the CLK signal of FIG. 5 since even though the CLK signal is locally generated in the Master Synchronizer, each transmitter and each re¬ ceiver, these signals will nevertheless all be in synchronism because they are derived from the same Incoming sync pulse on the sync line 15.If the input signal is true or one as indicated on line L7 of FIG. 6, then a strobe pulse such as the one designated 190 occurring in the first half cycle of the local clock signal will cause the one output of the flip flop 176 to go high as at 191 on line L10. Similarly, If the input signal had been false or zero as indicated on line L8 of FIG. 6, then the zero output of flip flop 176 will go high when the strobe pulse 192 clocks the flip flop 176, the output being indicated on line Lll, and going high at 193.In either case, as Indicated above, an energy- containing pulse is required toactuate the flip flop 176, as well as the photocouple 179. In operation, when an in¬ coming signal causes the photocouple to conduct, SCR 191 also conducts. This, in turn, will cause current to flow through bridge 192 and resistor 197 to apply a gate voltage to cause the triac 194 to conduct, thus connecting the load to the ac source. | CLAIMS1. In a multiplex system for communicating a sensor device with a remotely located control device including a synchronization line; and a signal line; the improvement characterized by master synchronization circuit means for generating a synchronization signal coupled to said synchro¬ nization line, said synchronization signal being generated each time frame and including a periodic signal portion and a reset signal portion, each cycle of said periodic signal portion defining a time slot in said time frame; a plurality of transmitters, each including trigger- able counter circuit means and being connected to said synchronization line and said signal line and responsive to said reset signal portion of said synchronization signal for loading a predetermined count representative of an assigned time slot into said counter means, said synchronization sig¬ nal portion being operative to trigger all transmitter coun¬ ter circuit means simultaneously, each transmitter further including gating circuit means responsive to said counter circuit means reaching a predetermined count for coupling an output signal of said sensor to said signal line; and a plurality of receivers, each including triggerable counter circuit means and being connected to said synchroni¬ zation line and said signal line and responsive to said reset signal portion of said synchronization signal for load¬ ing a predetermined count representative of an assigned time slot into said receiver counter means, said periodic signal portion being operative to trigger all of said receiver counter circuit means simultaneously, each receiver further including output circuit means responsive to said counter circuit means reaching a predetermined count for coupling a signal on said signal line to an associated control device during the time slot associated with that receiver.2. The apparatus of claim 1 wherein said master synchronization circuit means includes oscillator circuit means responsive to a control signal for generating said periodic signal portion when said control signal is in a first state and for generating said reset signal portion when said control signal is in a second state, said synchronization circuit means further including triggerable counter circuit means for generating an output signal when the contents thereof reach a predetermined count at least as great as the number of time slots in a frame; reset circuit means responsive to the absence of an output signal from said oscillator means for a predetermined time for loading said counter circuit means to a predetermined count for initiating an operation of said oscillator circuit means; circuit means for triggering said counter circuit means responsive to the periodic signal portion of said synchro¬ nization signal, the output signal of said counter circuit means inhibiting further operation of said oscillator cir¬ cuit means until said counter circuit means is re-loaded by said reset by said timer circuit means.3. The apparatus of claim 2 wherein said reset signal portion of said synchronization signal consists of the absence of periodic signals from said oscillator circuit means.4. The apparatus of claim 2 wherein each of said transmitters and receivers further includes reset timer circuit means responsive to said reset signal portion of said synchronization signal for re-loading associated coun¬ ter circuit means, the reset signal time of said Master Synchronizer being longer than the reset signal time of said transmitters and receivers.5. The apparatus of claim 1 wherein said system includes a plurality of sensor devices capable of generating a binary signal having first and second states, and a plu¬ rality of control devices capable of responding to a binary signal having first and second states, each transmitter including clock circuit means responsive to said periodic signal portion of said synchronization signal for generating a clock signal; output gate circuit means responsive to the output signal of said transmitter counter circuit means and to the binary output signal of an associated sensor device and to said clock signal for generating a first output pulse signal on said signal line during one portion of said clock signal if said sensor device is in a first binary state andO for generating a second output pulse signal on said signal line during a second portion of said clock signal if said sensor device is in said second binary state.6. The apparatus of claim 5 wherein each of said receivers includes clock circuit means for generating a clock signal; strobe generator circuit means responsive to said clock signal for generating a strobe signal a pre¬ determined time after said clock signal; output gating cir¬ cuit means responsive to the output signal of said receiver counter circuit means and the receiver clock signal and the signal on said signal line from an associated transmit¬ ter; and output circuit means responsive to said gating circuit means and to said strobe signal for generating a first signal if the sensor of an associated transmitter is in a first binary state and a second signal if the sensor associated with said transmitter is in a second binary state.7. The apparatus of claim 1 wherein each of said master synchronization circuit means includes decrementing counter circuit means; encoder circuit means for storing signals representative of the number of cycles desired in said periodic signal portion of said synchronization signal; master oscillator circuit means for generating an oscilla¬ tory signal only when said counter circuit means is not decremented to zero; reset timer circuit means responsive to the absence of an output signal from said master oscil¬ lator circuit means for a predetermined time for re-loading the contents of said encoder circuit means to said counter to re-initiate a time frame; and clock circuit means res¬ ponsive to the output signal of said master oscillator means for decrementing said counter means. | CONTROL JUNCTIONS; CONTROL JUNCTIONS INC | MORELAND C |
WO-1979000355-A1 | 1,979,000,355 | WO | A1 | EN | 19,790,628 | 1,979 | 20,090,507 | new | H02P7 | B60L15 | B60L15, H02P7 | B60L 15/08, H02P 7/28B | CONTROL SYSTEM FOR A D.C. MOTOR | A d.c. motor control system, intended primarily for use in battery powered vehicles, includes a control switch (RLa, RLb) for varying the connections of the motor field winding (24) to determine the mode of operation of the motor and speed interlock means for preventing said control switch being operated to change the motor mode whilst the motor is actually running. Instead of using a mechanical speed transducer the speed interlock means includes means for supplying current to the motor field winding (24) when current would not otherwise be flowing therethrough and means (BR1, T<u1>u, P<u16>u etc.) connected to detect the voltage across the armature which occurs in these circumstances if the motor is in motion. | Technical fieldThis invention relates to a control system Tor a d. c . motor .Background ArtControl systems nave previously been proposed for electric vehicle motors in which there are interlocks bet-ween various driver operable controls and control devices in the control system to prevent damage to the system. For example , one such interlock may be provided to prevent a control device in the form of a contactor controlling' the connection of the motor for reverse ajad forvard motoring from being operated except when the vehicle is at rest . Such, an interlock, which vill be re erred to hereina ter as a speed interlock , necessitates the provision of means determining whether or not the vehicle is in motion.In the previous proposals the control system has in¬ cluded a speed transducer which is used both for providing logic signals for use in the speed interlock functions and for providing analog signals for the control system. T e speed transducer was a mechanical device driven by the • traction motor and producing a puls e train, the frequency of which was proportional to speed. Such a transducer added considerably to the cost and complication of the con¬ trol system and, being a mechanical device , required main¬ tenance .It is an object of the invention to provide a control system for an electric vehicle traction motor incorporating at leas t one spe ed interlock function but no me chanical speed transducer .Dis cloaurs of inventionIn accordance with the invention there is provided a control system for d. c sαtor comprising control means for varying the connections of the motor armature winding and/ field winding so as to enable the motor to operate in a pi rality of different modes, and speed interlock means for preventing operation of said control means to change the motor connections from at least one mode to at least one other mode whilst the motor is running characterised in th said interlock means is sensitive to the voltage across th armature winding of the motor and means are provided for supplying a field current to the field winding when said interlock means is required to be operative.Thus, when a change over from forward drive to revers- drive is demanded, for example, the speed interlock means will be required to be operative at a time when the field and armature currents would otherwise be zero. When it is required for the speed interlock means to be operative a current pulse is applied to the field winding. If the moti is at rest the voltage across the armature winding will be zero. If, on the other hand, the motor is running, a voltai signal will be generated by the motor which signal is detβc ted and used to prevent the change-over.Alternatively it can be arranged for the field curreni to have a predetermined minimum level below which it is never allowed to fall.Brief Description of DrawingsAn example of the invention as applied to an electric¬ al vehicle d.c. traction motor control system is shown in the accompanying drawings in which, 'Figure 1 is a block diagram of the armature and field winding current controls, Figure 2 is a block diagram of a logic circuit associated with the circuit of Figure 1, Figure 3 is an electrical circuit diagram of the armature current control portion of Figure 1, Figure k is an electrical circuit diagram of an armature chopper circuit and current signal generator circuit forming pa-rt of Figure 1, Figure 5 s an electricaJ circuit diagram of a field current conrrol circuit portion of Figure 1, Figure 6 is an electrical circuit diagram of_ a field chopper circuit fprming part of Figure 1, and Figures z. f 7TD and c_ together make up the electrical circuit diagram of the logic circuit of Figure 2.Best Mode of Carrying Out The InventionReferring firstly to Figure 1, the armature current control makes use of an armature chopper circuit 10 which is shown in detail in Figure k . Three thyristor drive circuits 11, 12, 13 control the chopper circuit 10, these drive circuits deriving their input rom1 a Schmitt bistable circuit 1^. This Schmitt bistable circuit 1 receives its input from a difference amplifier 15 which receives at one input terminal a signal representing the instantaneous armature current demand and at its other input terminal a current feedback signal from a current signal generating circuit l6.' The current demand signal is generated by selecting the larger of two voltages on the sliders of two potentiometers 17, 18 operated respectively by accelerator and brake pedals controlled by the driver of the vehicle in which the system is installed. Such selection is carried out by a comparator circuit 19 • The. potentiometers 17, 18 are connected between respective output terminals of a demand shaping circuit 20 intended to reduce the maximum possible demand . signals with increasing vehicle speed. In fact such shaping is carried out without the use of a mechanical speed transducer, signals already present in the system being used instead. This arrangement is described in detail in copending application number 51066/77 Q£ even date to which reference may be had for a full description of the circuit 20. A demand detector circuit 21 is also connected to the sliders of the potentiometers 17, 18 and provides a control signal to the field current control as well as an input to the logic circuit of Figure 2. The field current control includes a field chopper circuit 22 which supplies current via a forcing and reverε ing relay network 23 to the motor field winding 2k , The field chopper circuit 22 is connected to a Schmitt bistabl circuit 25 via an βpto-isolator 26. The Schmitt bistable circuit receives a linear aignal from a field current com- paratβr 27 which receives one input from a field current demand signal generator 28 and another from, a field curren signal generator l6ει. The field current demand signal generator 28 has inputs from the output of the comparator from the demand detector 21, from various points in the logic circuit of Figure 2 and also from a field weakening difference amplifier 9. This latter amplifier 2$ receive inputs from a start up circuit 2>0 and from a further amplifier A5 which is operative during braking to compare the output of amplifier 15 with a fixed reference value.Before turning to the detailed circuit diagrams the block logic diagram of Figure 2 will be briefly explained. Basically the function of the logic circuit is tβ control relays RL1 axd RL2 in the field current control and a contactor RL3 in the armature current control, and also tα control the sequence of events when the system is switched on and off, so that a properly controlled power up and pow eff sequence occurs. An ignitiβn switch circuit kO contra the supply of power to a power relay k-3. which controls the supply of current to regulators 2 for supplying regulated voltages to the electronic control and logic circuits and also to a main isolator & (shown in- Figure h ) . There are also various interlocks controlling the energising and de- energising of the power relay k-1. such interlocks ensuring that the system cannot be brought into operation when the vehicle battery is on charge , when the 12V auxiliary battery is discharged, when the vehicle is moving or when there is sin armature current demand signal present. - -A block 43 in Figure 2 represents a logic circuit (controlling the relay RLl) which is effective during change over between the various motor operating modes i.e. forward motoring, reverse motoring and braking, and serves tβ ensure that the field current is rapidly reduced to zero, before the newly selected mode is brought into opera¬ tion. A logic circuit 44 controls the relay KL2 and the contactor RL3 and also provides inputs to phase check gates • k-5 which are responsible for bringing the field forcing logic into operation. These gates detect the condition vhich occurs when the driver has selected a new mode of operation but the various conditions required for change-over have not yet been met.For providing a speed logic input to the interlock circuit' 3a and the logic circuit 44 there is an armature voltage detector 46 (shewn in Figure 7£.) vhich is used instead of a speed transducer.Finally Figure 2 shows a demand clamping circuit 7 which receives inputs from the field force logic 43, the logic circuit 44 and from proving contacts on the contac¬ tor RL3» to control demand clamping signals applied to the comparator circuit 19» and the field current demand signal generator 28, during changes in mode of operation of prevent demand signals being generated at these times.Turning now to Figure 3, the armature, current control circuit includes the demand shaping circuit 20 which applies a maximum voltage appropriate to the existing vehicle speed to the non-earthy ends of the potentiometers 17 and 18. The comparator circuit 19 includes an operational amplifier Al (vhich is a current differencing type operational amplifier such as ■£• National semiconductors type LM 3 00) • The sliders of the two potentiometers 17, 18 are connected by respective resistors R , R^ to the inverting and non- inverting input terminals' of ampli ier A... Hysteresis is provided by a feedback resistor R_ to the non-inverting input terminal. The output terminal of amplifier A. is connected to a teππ±nal marked MTR/BK which is connected to the logic circuit 44 and is at high voltage when the voltag on the slider of the brake potentiometer is higher than tha on the slider of the accelerator potentiometer.The demand detector 21 of Figure 1 is represented by a npn transistor N. with its base connected to the common point of two resistors R and R- connected in series betwee the sliders of the potentiometers 17 and 18. The emitter of the transistor N_ is connected to the earth rail of the supply and it is biased so as to be just non-conductive whe: there is a zero voltage at the sliders of both potentiomete: 17, 18. The bias circuit for the transistor N., consists of a pair of resistors R^, R_ in series between the base-, of the transistor N_ and the +8v supply rail, a resistor E„ connecting the base of the transistor N_ to the earth rail and a diode D. with its anode connected to the common point of resistors R,-, R,^ and its cathode connected to the earth rail. A capacitor C. is connected between the base of the transistor N. and the earth rail. A very small voltage on the slider of either potentiometer 17 or 18 will suffice to turn on transistor N which has its collector connected to the +8v rail by two resistors Rq, R..Q in series. The common point of these resistors R_, R_ _ is connected to the base of a pnp transistor P. which has its emitter connected te the +8v rail and its collector connected to a terminal marked D>0 which is connected to interlock circuit 4l. A diode D„ connects the collector of the transistor N_ to a terminal marked b_ (see Figure $ ) .The motor/brake comparator circuit 19 also includes an arrangement whereby only the larger of the two voltages at the sliders of the two potentiometers 17, 18 is passed on to the amplifier 15. This arrangement includes a pair of npn transistors N^, N_ with their bases connected by respective resistors R , R.. „ to the sliders of the poten¬ tiometers 18 and 17 respectively. The emitters of these transistors N_, N are connected together and a common resistor R_ _ connects them to earth. A pair of capacitors C_, C_ connect the bases of the transistors ϊl„ , N to the earth rail and the collectors of these transistors are connected together and via a common resistor R_ to the cathode of a diode D , the anode of which is connected to the +8 rail.It will be appreciated that only the transistor N_ or N_ which has its base at the higher voltage will conduct at any given time and that transistor will then act as an emitter follower, so that the voltage on the resistor R_ „ will be just one V below the voltage at the slider of the appropriate potentiometer. The resistors R _ and R_ ? and the capacitors C2, C„ act to limit the rate of change of the output voltage of the circuit, each R-C circuit having a time constant of some JOuiS . These also act as noise filters .Two terminals M and B of the demand clamp circuit 7 (see also Figure 7 b) are connected directly to the bases of the transistors N„ and N so that when the signals at these terminals are both low, the transistors are turned off. There are two output terminals c_ and e^ shown in Figure 3» Terminal c is connected to the emitters of the transistors Np and N_ and also to the field current control (Figure 5)* Terminal _ is connected to the collector of a pnp transistor P« which has its base connected to the collectors of the transistors N≥ and N„, its collector connected to the +8v rail by a resistor R.. r- and its emitter connected to the same rail by a resistor ^--, 7 ' Terminal _e_ provides an input to the field current demand signal generator 28 (see also Figure 5) anc* acts as a current source providing a current with a minimum level determined by R and increasing lin¬ early with the voltage at the emitter of the transistors N2 and N .The amplifier 15 which is another integrated .circuit current differencing operational amplifier (eg -J- LM 390°) is connected to operate as a linear difference amplifier. To this end the non-inverting input terminal of the amplif 15 is connected by a resistor R_ g to the output of an R.C. filter circuit R-< QJ C. across the resistor Rη _ , and is als. connected by a resistor R,,-. and a variable resistor R? in to the +8v rail (to provide bias current). The inverti: input terminal of amplifier 1 is connected by a bias resistor R„2 to the +8v rail and by a resistor R„_ to a terminal marked I . from the current signal generatorSZ g circuit l6 (see also Figure 4). The output terminal of th' amplifier 15 is connected by a capacitor C to the earth rail and also to the anode of a diode D.. The cathode of the diode D, is connected by a feedback resistor R_. to th< inverting input terminal of the amplifier 15.The amplifier 15 produces an output signal which is linearly related to the error between the demanded armaturt current and the actual armature current as measured by circuit 16.This error signal is applied via a resistor R2 to thi inverting input terminal of an operational amplifier A_ on which the Schmitt bistable circuit l4 is based. The non- inverting input terminal of the amplifier A„ is connected • the +8v rail by a bias resistor „, and normal feedback is provided via a resistor R„_ between the output terminal of the amplifier A_ and its non-inverting input terminal to provide hysteresis (ie to set the switching threshold voltages above and below that determined by the biasing resistor R„g). The Schmitt bistable circuit has outputs to the three thyristor drive circuits 11, 12 and 13. The output to the thyristor drive circuit 11 is taken from the common point of the two resistors R π and Q in series bβtween the earth rail and one side αf a capacitor C >- . The other side of capacitor C^ is connected to the collector of a pnp transistor P vhich has its emitter connected to the +8v rail, its collector connected by a load resistor R_Q to the earth rail and its base connected to the common point of two resistors R__ , R~2 connected in series between the +8v rail and the output terminal of the amplifier A . The transistor P turns on when the output of the amplifier A2 is low so that there is a positive going output pulse delivered to drive circuit 11 when the output of amplifier A2 goes low. This occurs when the actual armature current falls below the demand current by more than the' margin established by the hysteresis of the Schmitt bistable.The input to the drive circuit 13 is taken from the common point of two resistors R,,~ Ξnd R„(ι connected in series between the earth rail and one side of a canacitor C„. The( other side of the capacitor C is connected to the collector of a pnp transistor P> , the emitter of which is connected to the +8v rail and the collector of which is connected by a load resistor R to the earth rail. The base of the transistor P. is connected to the common point of two resistors tween the +8v rail and the collector of an npn transistor ^, the emitter of which is connected to the ground rail. The base of the transistor N. is connected to the common point of two resistors R 0, _0 connected in series between the earth . ° y rail and one side of a capacitor C„, the other side of whicα is connected to the output terminal of the amplifier ~ .Said one side of the capacitor C„ is also connected to the cathode of a diode D_, The anode of which is connected to_> the earth rail.The transistors . ' and P, turn on for a time dependent on the time constant of the cauacitor C~ with the resistor8R o, R (typically about 0.7ms) when the output of the amplifier A2 goes high. At the same time a short duration positive going pulse is passed to the drive circuit 13.The capacitor Cg and resistors R g, R_ provide part of a ττHτHτπ-nm off-time circuit which is associated with the Schmitt bistable circuit l4. The remainder of this minimun off-time circuit is provided by a resistor Rrn and a diode I. J- in series between the collector of the transistor P. and the non-inverting input terminal of the amplifier 2. These components ensure that, however the input to the Schmitt bistable circuit behaves immediately following the output of amplifier - going high, the output of amplifier A will not go low agai for a preset time, i.e. until transistors P^ and N switch off when capacitor C„is charged up, because of the additional heavy position feed¬ back to the amplifier 2# The input to the drive circuit 12 is derived from the signal at the collector of the transistor P^ via a mono- stable delay circuit based on an operational amplifier A_. The collector of the transistor P, is connected via a capacitor CQ and a resistor R^, in series to the inverting input terminal of the amplifier A_. The non-inverting inp terminal of this amplifier is connected by a bias resistor R.2 to the +8v rail and by a positive feedback resistor R^, to the output terminal of amplifier A-. A diode D_ has its anode connected to the output terminal of the amplifier A_ and its cathode connected by a resistor R, . to the inverting input terminal of the amplifier A_ to provide negative feedback when the output of amplifier A is high, a capacitor Cη_ connecting the cathode of the diode D to the earth rail.When transistor P^ turns on the output of the ampli ie A goes low until capacitor C has discharged through the resistor R. , . The output of amplifier A_ then goes high again the capacitor C having meanwhile become fully charge and remains high until transistor P,, turns on again. TheBUKEA output terminal of amplifier is connected to the earth rail via a capacitor C _ and two resistors and the input to the drive circuit 12 is taden from the common point of these resistors.The armature chopper circuit shown in Figure 4 includes a mai thyristor THI, a coπnπutating thyristor TH2 and a ring-round thyristor TH3, which are connected to be triggered by the dr±ve circuits 11, 12 and 13 respectively. The main thyristor TΞl has its cathode connected via a main fuse 50 to an earth conductor and its anode is connected to one end of the armature winding 51 of the motor. The other end of the armature winding $1 is connected via a contact RI 33- of the contactor RI 3 to a high voltage positive supply conductor, the positive and negative supply conductors being connected by the isolator contacts 48 to the terminals of a high voltage (e.g. 200-300 volts) battery. A power diode Dg has its cathode connected to said other end of the armature winding 51 and its anode connected by an auxiliary fuse 2 to the earth conductor. This diode is operative during braking, when the contact Rl 3a is open. A further power diode Dq has its anode connected to the anode of the thyristor THI and its cathode connected to the supply rail. This further diode is operative to conduct decaying armature current each time the main thyristor THI is turned off. A resistor R_n and a capacitor C-2 are connected in series between the anode and cathode ef the thyristor THI. The commutating thyristor TH2 has its anode connected to the anode of the main thyristor THI and its cathode connected by a fuse 53 and an inductor 4 to one side of a commutating capacitor C „, the other side of vhich is connected to the earth conductor. Said one side of the canacitor C,_ is also connected via a resistor R_„ and a 1 _sl diode D _ in series to the supply rail. The ring-round thyristor TH3 has its cathode connected to the earth con- ductor and its anode connected via an inductor _05 to said one side of the capacitor C _. Vhen thyristor THI is fired current flows through the armature 1 and the relay contact L3 (assuming this to b« closed). Vhen the armature current reaches a sufficiently high level for the output of the amplifier A2 (Figure ) tc be driven high, the thyristor TH3 is fired immediately and the thyristor TΞ2 is fired after the delay mentioned above. The capacitor C_- is positively' charged at this time, charg having been maintained if the thyristor TΞl has been conducting for a long period by current trickling into the capacitor C _ via the resistor R .. Vhen thyristor TH3 fires, the capacitor C _ commences discharging through the inductor 55 , peak current being reached as the capacitβr C. becomes completely discharged. Current continues to flew in the inductor 55 > however, charging capacitor C_ _ to a peak reverse voltage at which thyristor TE3 ceases to con¬ duct. The delay set by the delay circuit constituted by the monostable circuit A is longer than the time taken by this ring-round βperation. Vhen thyristor TH2 is fired, however, the armature current is diverted in the now rever¬ sed charged capacitor C_„, allowing thyristor THI to turn off. This diverted armature current continues to flow unti the capacitor C_ „ again becomes fully charged in the origin sense whereupon thyristor TH2 turns off and the continuing armature current (new decaying) flows through the diode DQ. Vhen the armature current has fallen low enough to cause the output of amplifier A2 to go low again thyristor THI is fired. In this way the armature current is kept between predetermined limits relative to the demanded armature current.Figure 4 also shows the current signal generator 16 ofFigure 1, which includes an operational amplifier A, with its inverting and non-inverting input terminals connected by resistors i_ ~ nd R ;_?2? aand R_ „ 3_j„ to the output terminals of a Hall plate device 56 energised by two resistors R.^, R_^ connecting it to the +8v and earth rails respectively. A resistor Rςg connects the non-inverting input terminal of amplifier A. to the earth rail and an npn transistor N is connected as an emitter follower to the output terminal of the amplifier A.. A resistor R and a diode D in series connect the collector of the transistor N_ t* the +8v rail and the emitter of this transistor is connected by two resistors R g and R - in series to the inverting input terminal of the amplifier i. so that this operates as a difference amplifier. The emitter of the transistor N- is connected by a temperature compensation network to the ground- rail, such network consisting of two resistors Rg0, Rg, in series and a thermistor RT. connected across the resistor gn« The output to the difference amplifier 15 is taken from the junction of the resistors RgQ» Rg-i • To provide a logic output when there is no difference input to the amplifier ^ (i.e. when the armature current is zero), a -DUΌ transistor P_ has its base connected to the collector of the transistor N_,its emitter connected to the +8v rail and its collector connec¬ ted to the motor/brake logic circuit 44 (see Figure 2 and Figure 7b) .Turning now to Figure * the field current control circuit includes the start up circuit 30 based on an npn transistor __!>_■ which has its emitter connected to the ground rail and its base connected to the common point of two resistors Rg^, 'h. across a capacitor C. - connected at one side to the ground rail and at the other side by a resistor ^_ to the output terminal of the amplifier A (Figure 3). A capacitor C. ,- connects the collector of the transistor -. r to the ground rail such collector being also connected by a resistor R D,-O,- to the outnut terminal of the difference a nlifier 15 (see Figure 3)« The transistor ^ isD normally on, capacitor C . _ charging up whenever the output of amplifier A is high and discharging only slowly vhen the.BUR A iT - 1k-output of amplifier A„ ±s lov (i.e. vhen thyristor THI is on) » Should the output of amplifier A_ remain lov for an extended period (indicating- that the demanded current cannot be achieved) transistor N,- turns off, permitting it collector to follov the signal at the output of the difference amplifier 15•The collector of the transistor Ng is connected to th anode of a diode E,-,j the cathode of vhich is connected by a resistor R_0 to the inverting input terminal of the difference amplifier 9 (Figure l). The non-inverting input terminal of amplifier 2 is connected by a bias resistor R__ to the +8v rail and a feedback resistor Re¬ connects the output terminal of the amplifier 2 to its inverting input terminal. The ripple rejection circuit shorn in Figure 1 is constituted by a resistor -.^.- and a caυacitor C,,„ in series betveen the cathode of the diode . 11/D _ and the non-inverting input terminal of the amplifier .Current can flov into the inverting input terminal of the amplifier 29 via the diode D__ vhenever the signal at the output terminal of the amplifier 15 is high and the transistor ^ has turned off. These conditions occur only during forvard motoring. Alternatively current can flov into the inverting input terminal of the amplifier 29 via a diode E... from the output terminal of an amplifier A_ connected- as an inverting amplifier producing an output dependent on the difference betveen the signal at the of the amplifier 15 and a reference value (set by a resistor R connecting the non-inverting input of the amplifier A., to the +Sv rail) . The a olifier A_ has its inverting terminal connected bv a resistor R I.„f 4, to the terminal A and by a resis tor R„ „ _ to its out-out terminal .■i- iThis current flov- o ccurs only during braking . In e ither^ R EA event, vhen the c-urrent loving into the inverting input terminal of amplifier 29 rises above that floving into the non-inverting input terminal, the output of the amplifier 2 vill fall linearly belov a normal high value.The output terminal of the amplifier 29 is connected by tvo resistors R__, R_.g to the +8v rail. Three further resistors -y Ryg aod R__ in series connect the junction of the resistors R~,-» ^- £_ *° kke ground rail. The junction of the resistors ^t ^rp. ^-s connected to the cathode of a diode E__, the anode of vhich is connected to the output terminal of an operational amplifier Ag. The inverting input of this amplifier A,- is connected to its output terminal by a resistor ao and to the +8v rail by a resistor .. The non-inverting input of the amplifier Ag is connected by a resistor RR2» ^° *^-e emitter of the transistor N_, N„ (Figure )* Amplifier Ag acts as a non-inverting amplifier of the voltage on the resistor R (Figure 3) to boost field current at high armature current demand levels.The junction of the resistors R„ ( oo» ∑ Qy is connected bv a resistor RQ_ to the base of an nun transistor N_ the emitter of vhich is connected to the eart rail viά. a resistor and the collector of vhich is connected to the collector of the transistor P (Figure 3) vhich is on vhenever a demand for motoring or braking is present.The transistor N can be turned off either by the signal t a terminal F (see Figure 7b) going lcrv or an npn transistor N„ being turned on. Transistor „ has its emitter connected to the ground rail, its collector connec¬ ted to the base of the transistor X_ (and to terminal F) and its base connected to the junction of tvo resistors ts0 - 8;-? and Ro(- vhich are in series betveen a terminal F' (Figure 7JD) and the ground rail. Terminal F1 is also connected to the anode of the diode D (Figure 3) so that transistor No can turn on only when the signal at the terminal F' is high and transistor N (Figure ) is off (indicating that neither brake nor accelerator pedal is depressed).The transistor N_ acts (vhen transistor P„ is on) as an emitter follower and its emitter is connected by a resistor RθP_ to the non-inverting incut terminal of the field current difference amplifier 27, vhich terminal is also connected to the +8v rail by a resistor Rfi„. A resistor RQ. connects the inverting input terminal of amplifier 27 to the +8v rail and another resistor RQn connects this terminal to the output of the field current signal generator 29 vhich is similar to the armature current signal generator l6 (shown in detail in Figure k ) _ Feedback around the amplifier 27 is provided by a resistor RQ_ and a capacitor C in parallel vith each other between the output and inverting input terminals of the amplifier 27.The Schmitt trigger bistable circuit 25 of Figure 1, i constituted by an operational amplifier A vith a resistor R „ connecting the output term n l of amplifier 7 to the inverting input of amplifier A_« The non-inverting input o amplifier A_ is connected by a resistor R_- to the +8v rail and by two resistors RQL » RQ- in series to the output- terminal of amplifier A_, a capacitor C.g being connected across the resistor Rqt-»The output of amplifier 27 rises and falls linearly vith the error between the demanded field current and the actual field current. ∑n steady state conditions RQ. , RQE- ^ r> _z> provide a small positive - feedback current which establishes hysteresis in the oneration of amtilifier „ so that the i output of amplifier A goes low when the output of amplifier 27 rises above one set level and goes high when the output aurolifier 27 t falls below a lower s et leve The capacitor C-o introduces additional positive feedback for a short period immediately following each change in level of the output of amplifier A_, thereby inhibiting a further change in level for this period, irrespective of how the output of amplifier 2 behaves.The output terminal of amplifier A^, is connected by a resistor _ to the base of an npn transistor Ng which has its emitter connected to the earth rail and its collector connected by a resistor Rq_ to the +8v rail. A further npn transistor Nq has its base connected to the collector of the transistor Nr>, its emitter connected to the earth rail and its collector connected by a resistor RQo and the light-emitting diode of the opto-isolator 26. ,Turning now to Figure 6 it will be seen that the photo-transistor of the opto-isolator 26 has its base connected by a resistor R..OQ to the earth rail and its emitter connected directly to the same rail. The collector of the photo-transistor is connected by a resistor R-,Q-. to a +12v rail connected to a tapping on the traction battery and is also connected to the base of .an npn transistor N_ _ which has its emitter connected to the negative supply rail and its collector connected by a resistor R,n2 to the +12v rail. The collector of the transistor N. _. is connected to the base of an npn transistorN_ . the emitter of which is connected to the earth rail.An npn transistor N. ? has its collector connected to the base of the transistor N. - and its emitter connected to the earth rail. The base of the transistor N_2 is connected to the collector of an npn transistor N. „ which has its emitter connected to the earth rail and its collector connected by a resistor R ±-,πJj~ to the ÷12v rail. The base of the tran- sistor N is connected by a resistor Rιn^, to the earth rail and by two resistors , R g to the anode of a zener diode ZΩ. , the cathode of which is connected to the +12v rail. The collector of the transistor N__ by a resistor R-_,- is connected to the junction of the resistorsR105 aDd R106'The collector of the transistor N._ is connected to the cathode of a diode D2 » ^B anoc β 0 vhich is connected by a resistor R_ __, to the cathode of a diode D2_ , the anode of which is connected to the +12v rail. The cathode of the diode D21 is connected by a capacitor C to the earth railThe cathode of the diode D20 is connected by two resistorsR-0Q, K-irjq i21 series to the +12v rail. The anode of the diode D_0 is connected by two resistors R _ and R_ _ in series to the earth rail. An npn transistor N. has its base connected to the junction of the resistors R..Q andR_ _ , and a τmτι transistor T? _- has its base connected to the J. JL ~ o junction of the resistors R. _ and R-__. The transistors N-i and Pg have their emitters connected respectively to the negative supply rail and the +12v and their collectors interconnected by a resistor R- „.The collector of the transistor P,- is connected by a resistor R... _ and a capacitor C_. in parallel to the base of an npn transistor N the emitter of which is connected to the base of an npn transistor N.g the emitter of which i connected to the negative supply rail. The collectors of the transistors N_ and N.. - are connected together and a diode D22 has its cathode connected to the base of the transistor N. _ and its anode connected to the base of the transistor -N-g. The collectors of the transistors N.._, N.g are connected to the normally closed contact of a change¬ over contact set R 2a of the relay RL2 and also to the normally open contact of a change-over contact set RL2b of the relay R 2. The other contacts of these two contact set are connected together and via a normally closed contact RLla of relay RL1 to a high voltage supply via a filter „. The field winding 2k is connected between the common terminals of the contact sets RL2a, R 2b. The collectors o transistors N.ς, N.. r are also connected by a diode D2 to the output of the filter F , a further diode D ■ connecting the said other contacts of the contact sets R 2a, RL2b to the negative supply rail. In addition, a capacitor C22 connects the collectors of the transistors N.„, N_g to the anode of a diode D?_ the cathode of vhich is connected to the negative supply rail. A resistor R . r is in parallel vith the diode B2ς* A resistor R-j.77 in series with a capacitor C?_ connects the cathode of diode D2 to the cathode of diode D? }, * a. diode D2g bridging the resistor1/ / •Referring now to Figure z__t the +12v supply is connectec to one side of an ignition switch kθ . The other side of the switch 0 is connected to the common pole of a three way direction selector switch 6θ having reverse, neutral and forward contacts. The reverse and forward contacts are connected to the anode of two diodes -D-,0 J D_. which have their cathodes connected together and, via a resistor R- nπ to the cathode of a zener diode ZD„ the anode of which is connected to the earth rail. A t>air of resistors R,201 and R^o? connect the reverse contact of the selector switch 6θ to the earth rail, the junction of these resistors being connected to the base of a npn transistor N. _ which has its emitter connected to the earth rail and its collec¬ tor connected to a terminal marked g (see Figure 7^,) • The neutral contact is connected to the anode of a diode D„2 the cathode of which is connected via the power relay winding 0 to the collector of an npn transistor N „• The. relay kl has normally open contacts k±z which control the supply of power to all the control circuits. For energising the relay θ there is a further diode D _ which has its anode connected to the +12v supply rail controlled by the contacts 1^ and its cathode connected to the cathode of the diode D 2* ^ reew el diode D , is connected across the relay winding *+l. The base of the transistor N _ s connected by a resistor R-0„ to the earth rail and by two resistors R2θ ' ^20^ ^ 3 er^e s ^° th.e cathodes of two diodes D _ and zVi c . The anode of the - diode D__ is connected to the3° 35 neutral contact of switch 60, and the anode of the diodeD_g is connected to the collector of a pnp transistor P . The emitter of the transistor P_ is connected to the +12v and its base is connected to this same rail by a resistor 20g and by two resistors R207> &208 ^n ser es ^° ii β collector of an npn transistor N . A capacitor C__ connet the common point of resistors ea t rail and a capacitor C__ connects the junction of the resistors R207 and 20o to the +12v rail.A diode D has its anode connected to the collector c the transistor P and its cathode connected by two resistoiR2θq, R210 i21 series to the earth rail and by two resistorsR2^ _ , R2-ι2 in series to the +12v rail. A capacitor C_2 is connected between the earth rail and the common point of tl resistors R2Qq , R21Q which point is also connected to the cathode of a diode D 3_°0 the anode of which is connected to the cathode of the zener diode ZD2< Two resistors R2To ancR_ . a1*8 connected in series across the capacitor C 2 and their junction is connected to the base of the transistor N q. A pnp transistor P^ has its base connected to the common point of the two resistors ^211 ^212' *^e ecιi k','er c the transistor P„ being connected to the +I2v rail and its collector being connected via a resistor R-21g to a terminal f (see figure 7b).A further diode D has its anode connected to the common point of the resistors ^?0q» ^210 axLC ^~ts ca'<;^l-0ie connected to the collector of an npn transistor „ and also connected to the anodes of two diodes D^_ and D.. the cathodes of which are connected to two interlock functions, one being a switch contact in a charger plug and the other being a contact which is normally held open when the battei-y voltage is not too low for satisfactory operation. The emitter of the transistor N„n is connected to the earth rail and its base is connected to the common point of two resistors R„ . „ f R2,o i series between the collector of an npn transistor N2- and the earth rail. The emitter of the transistor N2_ is connected to the earth rail and its base is connected to the common point of two resistors „ Q and H._20 in series between the switch 0 and the earth rail, The collector of the transistor N2_. is connected by a resistor R221 to the +5 supply rail. A resistor RZ2and a capacitor C__ are connected in series between the base of the transistor N2n and the +5v rail. The collector of the transistor N20 is connected by a resistor R22-ι o *ke cathode of a diode D.2 the anode of which is connected to a terminal h (see Figure 7^,) •An npn transistor __ has its emitter connected to the earth rail and its collector connected to the cathode of the zener diode ZD„ . The base of the transistor N2_ is connected by a resistor R22£, to the earth rail and is also connected to the cathode of a diode D> > • The anode of the diode D.. is connected by two resistors 22ς and 22f to two terminals marked SP>0 (see Figure 7_c) and D 0 (see Figure 3). A resistor R„„ and a capacitor C_. in series connect the anode of the diode D.. to the +5 rail. A diode D. has its anode connected to the anode of the diode D.. and its cathode connected to the collector of the transistor N Q.Turning now to Figure 7b_, the terminal h is connected to the .base of a pnp transistor Pq which has its emitter connected to the +5V r il The base of the transistor P.9 is connected by a resistor 2Λ0 to the +5v rail and by two resistors R^^ and 2^2in series to the output terminal of an exclusive OR gate Gl (■- of a TT integrated circuit type7^86). The junction of resistors f,-, »R2£ιois connected by a caDacitor C^_ to the earth rail. The anode of a diodeD, r- is connected to the collector of the transistor PQ and its cathode is connected by three resistors R-2Λ-,> ^2kk and R_ι _ in series to the rail, a capacitor C ,- being connected between the junction of resistors R_. _, . anc the earth rail. The junction of the resistors R„L. > ^- k *. ^ 3 coπnecte to the base of an npn transistor N2_ which has its emitter connected to the earth rail and its collector connected to the terminal F (See Figure 5).The collector of the transistor Pq is connected by two resistors A ' ^2*-7 ^ seI iΘS o the earth rail, the commo point of these resistors being connected to the base of a transistor N„^, which has its emitter connected to the eart rail and its collector connected by a resistor R O to the +5v rail. An npn transistor N2_ has its base connected to the collector of the transistor N2^, its emitter connected to the earth rail and its collecter connected by the windin of the relay RL1 to the +12v rail, a freewheel diode D2_ being connected across this winding.The collector of the transistor N, is also connected to the cathβde of a diode B..7' the anode of which is connec ted by three resistors R_. , R2e.Q and 2-, in series to the +5V rail. A capacitor C__ is connected between the common point of resistors ^2,q» 2ςn and the +5 v rail and the base of a pnp transistor P,Q is connected to the common point of the resistors R2c0 and R2c-t • T^e emitter of the transistor P is connected to the +5 rail and its collector is connected by two resistors 2c2» R2=;? ^ n series to the earth rail. The base of an npn transistor N2g is connected to the common point of the resistors R_ _ , R?,„ and its emitter is connected to the ea_rth rail. The collectβr of t transistor N2g is connected by a resistor Rp-j, to the +5v rail and also by a capacitor C_0 and a resistor R_ _ „ in3« 25 series to the base of the transistor P,n. The base of the transistor N2g is connected by two resistors R ς and R2r7 in series to the terminal marked ϋ>0 (see Figure k ) and a capacitor 0 39 is connected between the junction of these resistors and the earth rail. The collector of the transistor P _ is connected by a resistor R2gQ to the cathode of a diode D O* the anode of vhich is connected to the collector of a pnp transistor P which has its emitter connected te the +5v rail. A resistor R2£ι connects the base of the transistor P.. to the +5v rail and a resistor R-2g2 connects the same base to the output terminal of another exclusive OR gate G2. The anode βf the diode D. « is also connected to the anode of a diode Ω^q, the cathode «f vhich is connected by three resistors R2g^» R 6 and R2 *5 in series o the earth rail* A capacitor C. _ is connected between the earth rail and the junction of the resistors R2g~ and ^2g.. A diode D _ nas its cathode connected to the cathode of the diode D, q and its anode connected to the N terminal of the switch 60 (Figure 7^ ) * -A. further diode D-, has its cathode connected to the junction of the resistors R^,, and R^^-j, and its anode connected via a resistor R-2gg to the anode of the diode Djifi* The junction of the resistors R^c and R2gc is connected to the base of an npn transistor N2_ vhich has its emitter connected to the earth rail and its collector connected to the terminal M (see Figure _> ) . __ pair of resistors &2g7 and R-2gg are connected in series between the earth rail and the junction of the resistor R2g and .R2 ι * -An npn transistor N2„ has its base connected to the junction of these resistors R2£7 and R268' :^s e itter connected to the earth rail and its collector connected to the terminal BK (see Figure 3)«the cathode of a diβde D.„, the anode of which is connected to the collector of a pnp transistor P,?. The emitter of the transistor P 2 is connected to the +5v rail and its base is connected by a resistor R -Q to the +5v and by a resistor R„„~ to the collector of a tinp transistor P^ ( 0 - ^ 13The emitter of the transistor P is connected to the +5v rail and its base is connected by a resistor ^ to the +5 rail and by a resistor R2„2 to the output terminal of a further e clusive OR gate G3. The collector of the -2k-transistor P._ is connected by a resistor R27-, to the earth rail and also by a resistor 27 to the terminal F' (see Figure 5).An npn transistor N2q has its emitter connected to the earth rail and its collector connected by a resistor R27ς tβ the +5v rail and also connected to one input terminal of the gate G2. The base of the transistor N2q is connected by a resistor R27g to the earth rail and by two resistors R and R27o i series to the +5v rail. The junction of tϊ resistors 277 and R27g s connected by a contact RI 3b, of the contactor RL3 to the earth rail and also via a resistor R2_q to the anede of a diode D _ whose cathode is connected to the base of the transistor N2_. The collector of the transistor N_q is connected to the anode of a diode D-^, the cathode of which is connected by a resistor R R to the base of the transistor N_„.The relay winding RL2 is connected between the +12v rail and the collector of an npn transistor N__., the emittε of which is connected to the earth rail, a diode D2Q being connected across this winding. The base of the transistor N_n is connected by a resistor R2o-ι to the earth rail and by a resistor R2o2 to the collector of a pnp transistor P_2,» the emitter of which is connected to +5v rail. The base of the transistor P.κ is connected by a resistor R.„, to the +5v rail and by a resistor R2o , to the Q output terminal of a bistable latch circuit L (which may be of a TTL integrated circuit type 7^75).. The DATA input of the latch ..is connected to the output terminal of another exclusive OR gate G , and its CLOCK input terminal is con¬ nected to the collector of the transistor N2f-. The DATA input terminal of the latch L and its Q output terminal arε connected to the two input terminals of the gate Gi.BU tA The gate G has one input terminal connected by a resistor R_g to the +5v rail and also connected to the collector of an npn transistor N 1 , the emitter of which is connected te the earth rail. The base of the transistorU is connected by a resistor R„gg to the earth rail, by a resistor 2g7 to the terminal MTR/BK (see Figure 3) and by a resistor R2 o to the cathode of a diode D_„, the anode of vhich is connected to the earth rail. The cathode of the diode p m is also connected by a capacitor C. _ to the cathode of a diode D, τ which cathode is connected to the ground rail by a resistor R2g « ^ caPacit°r C^2 connects the cathode of the diode D_^ to the cathode of a diode D__ ° 51 which is also connected to the earth rail by two resistorsR_qo, and R2Q-, in series, the anode of the diode D _ being connected to the earth rail. An npn transistor N_2 has its base connected to the junction of the resistors R2qf.,R2q_ and also to the resistor R2l (see Fi ure 7a.) via terminal f. The emitter of the transistor N _ is connected to the ground rail and its collector is connected to the cathodes of two diodes D_0 and _„,, the anode of the diode D_0 being connected to the terminal F' and the anode DO of the diode D_q being connected via two resistors R^a * 2q^ in series to the earth rail. The anode of the diode D is also connected by a resistor R29 *° tlιe ajαode ° the diode Ω m r- , vhich is also connected to the collector of a pnp transistor P. _. The emitter of the transistor P-_ is connected to the + rail, and its base is connected to this rail by a resistor R2q_. A resistor R2q connects the base of the transistor P.. _ te the Q. output terminal of a bistable latch circuit L2 which has its CLOCK input connected to the collector of the transistor _, and its DATA input connected to the collector of the transistor N-... The Q, output termin¬ al of the latch 2 is also connected to an input terminal of the gate G2, via terminal m.The other input terminal of the gate G is connected to the Q output terminal of a third bistable latch circuit which has its DATA input terminal connected by a resistorR 97 to the +5v rail and also connected to the collector of thβ transistor N (see Figure a . The CLOCK input tβrmi al of the latch L_ is connected by a resistor ~0 to the +5 V rail and is also connected to a terminal n_ (see Figure 7£.).The junction of the resistors ∑ Q?and R2 T is cormβc ed to the base of an npn transistor N„_ vhich has its emitter connected to the earth rail and its collector con¬ nected by a relay vinding RlΛ to the +12v rail, the relay RlA having a normally open contact controlling the contact RI 3. The relay vinding RlΛ is bridged by a free-wheel diod D?Q and a capacitor G _k bridg ng i*s normally open contactTurning finally to Figure 7c, a bridge rectifier BR1 has its input terminals connected to opposite ends of the motor armature vinding. The negative output terminal of the bridge rectifier-is connected by a rail 70 to one end a transformer primary T_ . The positive output terminal of the bridge rectifier is connected by a resistor R.,nn ^° the cathode of a zener diode ZD_, the anode of vhich is connected to the rail 70. A capacitor C nis connected acπ the zener diode ZD . The unijunction transistor TJ. , has its base 1 connected to the rail 70» i^3 base 2 connected by a resistor R„π- to the cathode of the zener diode ZD_ a: its emitter connected by a resistor R„n? to the cathode of the zener diode ZD_ . A capacitor C__ is connected betveen the emitter of the unijunction transistor TJ. and the other end of the primary winding T_ , a diode D^n being connectec across the vinding T..The secondary vinding T_ of the transformer is conneci at one end to the +5^ rail. Its other end is connected by resistor -,Q-, to the anode of a diode D^-1 and the cathode c a diode Dg,» the cathode of the diode D^ being connected to the +5^ rail. The anode of the diode D-„ is connected o«c ιy a capacitor C to t5 tne + 3 rail and by a resistor R„Ok to the base of a ΌΠD transistor P. _, . A resistor R„__ lb 305 connects the. base of the transistor P ,- to the +5v rail and - the emitter .of this transistor .is connected to the same rail. The collector of the transistor P,/- is connected to the terminal marked SKXD and is also connected by a resistor - r to the base of an npn transistor N„. » the emitter of vhich is connected to the earth rail. A resistor R connects the base of the transistor N.,^, to the earth rail and the collector of the transistor N_ is connected by a resistor R o8 to the base of the transistor P g to provide latching action. The collector of the transistor N . is connected to the terminal n and is also connected by a capacitor C _ and a resistor ~0q in. series to .the base of a pnp tran¬ sistor R-i rγ * The emitter of the transistor P _ is connected to the +5 v rail and its collector is connected by a resistor R_10 to the base of the transistor . • The base of the transistor P._ is connected by a resistor R_.. to the +5v rail and by tvo resistors R^12» Rτ-π ^n seτ±es to the anode of a diode Dg„, the cathode of vhich is connected (via a terminal p) to the output terminal of the gate G3. A capacitor C_, connects the junction betveen the resistors R,..,2, ϊ ., to the earth rail.Having, thus, described the various components shown in Figures a. to 7c and the connections betveen them, the operation of the logic circuits vill nov be explained in detail.At start up, vhen the ignition svitch kO is closed and the svitch SO is in neutral position the transistor N „ can turn on, being supplied vith base current through the diode D and the resistors ^Qk nd ■R20 '* Current can then flow through the diode D„. and the relay coil kl . The contacts of this relay provide power to the circuits and also relay ' latching current via the diode D . Initially, the tran¬ sistor P is turned on via resistors R„. _ , R n , R so that its collector is high. The caDacitor C, _ charges up via the diode D_Q and the resistor R2g3 from the neutral contact of the svitch 6θ. Capacitor C/ιn holds on both'kO ttrraannssiissttoorrss NN„„__,, aanndd NN22gg vvhhiicchh aacctt ttoo clamp the motoring and braking demand signals to zero. When the svitch 6θ is moved to, say, the forward position, the transistor N__ receives base current via diodes D„Q and D_g and resistors R200a-nd R2lV T an.sistoN_Q conducts and causes transistor P to turn on via the resistors R20o a & ^217*r^3-^-s i-3 a latching arrangement and transistor N q is held on via diode E 7» and resistors o „ however, loses its supply of base current because the transistor P_ collector has gone high and PQ therefore tur7 o off, the function of which will be explained hereinafter.Also transistors N„_ and N2Q turn off after a delay whilst the capacitor C. _ discharges, since base current via the neutral svitch position has been lost, 'so that an armature current demand can now be made.There are certain restrictions and conditions govern± the selection of forward and reverse drive for safety reasons. Firstly, the transistor 2_ is turned on by a +12v. supply from the vehicle ignition switch kO through the resistor R21_. This keeps the junction of the resisto: R2.._ and R221 normally low (and transistor therefore of. except when first powering up the circuit when the +5v supply rises rapidly and transistor N2Q is turned on via tJ capacitor C_^ and resistor R.,22w^--^-s't capacitor C is charging up. Transistor -N.. turns on the transistor P through the resistor R.,2~ and the diode D, „ during this pe: od (approximately 25 S) for reasons explained hereinafter. At the same time another capacitor/resistor combination C_. and R -?7 kold the transistor N on for about 150π3. Transistor N_ prevents transistor ιq from turning on during this time because of the connection of the collector' Rt of transistor N2 to the junction- of resistor R on ajac^ diode D_Q. These delays ensure -correct starting up of the circuit when switching on and immediately selecting forward or reverse drive. There are also four interlock signals which prevent forward or reverse being selected, these being the charger plug interlock and auxiliary battery low cut-out vhich when low (Ov) hold the cathode of diode D low via diode D. or D. and prevent transistor N from turning on. The other two interlocks are provided by the D>0 and SP>0 signals, vhich, when high, turn transistor N22 on and also prevent transistor N „ turning on, so that if transistor N-Q is on these two signals can have no effect because transistor N22 is held off by the diode D- _ and the transistor N.q.Vhen the ignition switch θ is opened transistor Η„ loses its base drive and turns off, so that transistor N2_ turns on and removes the base current from the transistor N q via diode D « After a delay of about 200mS, while capacitor C-.. discharges, the transistor P turns off and transistor P„ turns on. This makes the collector of transistor Pg go high vhich is used, as explained hereinafter to make the contactor RI } open. The transistor P has previously turned on and clamped all the demand signals by turning on transistors N__, N2_ and N2g so that no current will be floving in the armature and field windings. After a further delay of about 150mS vhilst capacitor C_Q is discharging .the transistor Nlg turns off causing the relay kl to drop out and remove pover from the entire circuit. The vehicle can also be shut down by taking either of the interlock diodes D. Q, D^. to Ov, the same sequence than taking place. Vhen the vehicle is actually being driven forward (or is in the fox-ward drive connection mode and at rest) and reverse drive is required, svitch 6θ is operated to select reverse drive. In this reverse position base current for the transistor N._ is provided by resistor S-201 and transistor N._ therefore holds the DATA input of the latchL low. The latches can only change state vhen the signal at their CLOCK inputs are high and in the case of the lateL , this can only occur if the vehicle is not moving, movement being detected by sensing the voltage across the motor armature vith a small field current flowing. If a voltage is present the motor must be rotating, the bridg rectifier BR1 detecting such voltage (the polarity βf whic will depend on whether motoring or braking mode is in operation) . The output of the bridge rectifier BR1 is dropped by the resistor R,QO and the zener diode ZD to+15v. Capacitor C_0 provides smoothing during chopping when the armature voltage varies. The voltage across the caoacitor drives an oscillator based on the unijunctio transistor T , and the pulses generated by the oscillator transferred to the remainder of the circuit through the pulse transformer T_, T,,. The diodes -Dg-< » D >r2, the re¬ sistor R«,„„ and the canacitor C_„ form a diode punro circui303 D2- which acts to turn on the transistor P g via resistor R 0ΛThe transistor R,g turns on transistor N„. and also holds the CLOCK input of the latch L_ low to prevent change over of the latch.Yhen a change from forward to reverse is demanded the following sequence occurs:- The demanded change is detected and a small field current is applied to the motorAfter a delay, if no armature voltage has been detected, t change over is allowed. Normally the output of gate G3 is lov because both of its inputs are the same. Transistor and resistor enting the change over of latch 3.' Vhen the direction change is demanded the DATA input to latch L„ goes high, so that one input of gate G3 alse goes high as does the output of gate G3. Transistor P.„ turns off and transistor P _ turns on thereby clamping the armature demand via trainsistors ?_ and N2g« Transistor P__ turning off removes the supply of the base of transistor N„ (Figure 5) v a resistors 27L and Rg_ (Figure 5)« This releases the base of transistor N (Figure 5) so that a τm'τHπmτn field current demand is applied to the field chopper. A back emf is therefore generated if the motor is rotating. During this time the diode g_ has become reverse biased and capacitor C . discharges through the resistor R„ 2 into the base of transistor P__ and after a delay of about lOOmS transistor P__ turns off and transistor N_, also turns off, provided that transistor P..g is not on. Turning off of transistors P__ and N- is speeded up by the capacitor C__ and resistor R„oq providing positive feedback, thereby ensuring ά. fast edge to the signal at the CLOCK input of the latch L which is desirable for inter erence-free operation. The latch L_ can now change to the required state and its Q output is compared by gate G with the motor/bra-ke demand signal from the collector βf the transistor N„ . The output of the gate G goes to latch L_ whose output drives the field reversing relay RL2 via resistor i resistor R2g2 ωd transistor N__. This circuit arrangement gives the required field current directions for forward and reverse, motoring and braking as shown, in the following table:-•BU 1 ' -32-The relay RL1 is arranged to be operated for a suffici¬ ent time when a changeover is demanded to ensure reduction of the field current to zero. Thus the reversing relay RL2 is never required to break any current which could damage it: contacts. The change-over sequence is as follows :-The output of latch L_ changes as described above and the change passes through the gate Gk to the. latch L. DATA input. However, latch L.. cannot change immediately because transistor N26 is held on by transistor P 10■ ' and transistorN 2_. The demanded change is detected by gate Gl whose outpui goes low and turns on transistor Pq which turns on transistor 2 . The demand clamping transistors 2_, 2_ and N2„ are also turned on by the gate Gl output, thereby ensuring that there are no field or armature current demands , The tran¬ sistor 2j, clamps the base of transistor 2_ to Ov and therefore de-energises the relay RL1 so that its contacts open and the field current decays rapidly to zero. After a delay somewhat longer than that required to reduce the field current to zero (about 75∑πS), the capacitor C37 dis¬ charges and transistor P10 iurns off. Thus transistor N26 loses its base current from resistors R and also turns252Oil so that the latch CLOCK input goes high and latch Lχ ca change te its new state. Gate Gl then changes back to it normal high output state, the relay RLl is re-energisβd and the clamping transistors are turned off after short delays produced by capacitor C g with resistor R2j,£, and capacitor C^0 with resistors R (7,k εmd ^-2.6 ^° a^-^-ow ^kθ relays to attain their correct conditions. The vehicle is then drivable in the required direction. The same sequence of events occurs in the opposite direction of change over, except that the latches and gates end up in the required state as shown in the table above.Field forcing also occurs on switch on by the turning on of the transistor Pq via transistor 2n to ensure that nβ field or armature current demand is made before the relays have settled in their normal operating positions. At shut down a similar sequence occurs when the ignition svitch is opened or one of the interlock diodes D^Q, D,, . is taken low.The change over from motoring to braking is very similar to the forward-reverse change over. In motoring the MΓ /E selector (i.e. the output of amplifier A_ Figure 3) i-3 high so that transistor N__ is on and the output of latch 2 is low. Vhen the MTR/BK signal goes low, the DATA input of latch L2 and one input of gate G change state,latch L. therefore changes when transistor ^26 ^varΩ-s °££ as described above, also latch 12 changes at the same time. Thus transistors P. _ and N turn off, gate G2 detects the change (because of the delay in contactor RL3 operation). Transistor N„Q turns off and causes N2_ to turn on via resistors R-„o t 270and- diode D (in braking) or transistor 2g to turn on via resistorR275 and R280 a Ld diode Dc 2-11 motoring. This ensures that the braking demand is clamped in motoring a.nd vice versa. Vhile the Q output signal of larch L and the signal at the collector of transistor N„Q are out of phase, the output of the gate G2 is lov and the transistor P holds he transistors N „ and N„g on. These demand clamps are- t releas ed after the contactor RL3 has reached its new position, that is transistor P.. _ has turned off and removed drive to transistor N__ and the relay RL , so that the brake contact RL3 is in its de-energised state which is the normally open (braking) position. There are two further safety interlocks to protect the contactor:- namely on I 0 signal from the current transducer to tran¬ sistor N2g to prevent the latch changing if an armature current is flowing and transistor P.. conducts during chang' over to hold transistor N2g on so that the latch cannot change back to its original state until braking has been obtained and transistor P _ turns off. These interlocks ensure that there is no possibility of breaking a fault current.Because of residual magnetism in the motor it is desirable to ensure that the field current is reversed be¬ fore the contactor RL3 is closed into the motoring position to prevent large uncontrolled currents being generating in the armature 51 2-nd recirculating diode D_ . The I>0 interlock then prevents changing back into braking unless the motoring field is applied to reset the magnetic circuit in the motor. By resetting the field before closing the contactor, the problem is avoided. During braking, when change over to motoring is demanded the MTR/ BK signal goes high so that the collector of transistor N_1 goes low, the field reversal process takes place exactly as described above through gate G and latch L. after a delay for field forcing. The latch L2 also changes at the same time and transistor P turns on so that its collector goes high. This positive-going edge is transmitted through diode D ,- , capacitor C.2 επd resistor R2Qn to turn on transistor N„„ which removes the base drive to tran- sistor N_„ through diode D so that transistor N„_ cannot turn on. The relay RlA therefore stays de-energised and the contactor RL3 stays in the open (braking) condition until capacitor , ^ charges up and transistor N turns off. During this delay, .the Q output of the latch L,, and the contact RL3b are out of phase so that gate G2 output is low and the armature demand is clamped by transistor P.. supplying base current to transistor N2 and N2g. The field reversing relay has already changed and a reset signal is τjrovided by holding off the field claπro via diode D_05o and transistor N__ so that transistor 0 turns off and 2 o allows a small field demand to be made at the emitter of transistor N_ (the demand is for a current of approximately 2 amps). Because the transistor N_2 serves the dual role of holding the contactor in braking and allowing a field - current to flow in the correct (motoring) direction, the field resetting pulse must always occur at the right instant, i.e. after the field has reversed, but before the braking contact RL3 closes. Vhen the transistor N_2 goes off, the brake contactor RL3 closes, the output of gate G2 goes high and the armature demand clamps are released after capacitor CL. has discharged. The vehicle is then in the motoring mode with the magnetic circuit set in the right direction so that the recirculating diode DQ is reverse biased. To ensure that the field pulse always occurs correctly, the duration of the motoring signal at transistor N_. should be longer than the time required to change from braking to motoring. This is achieved by another capacitor-resistor network C^, , R-„o connected to the base of transistor N_. to hold that transistor on when the collector of transistor P. goes high until the capaci¬ tor C.. is charged. This delay is made slightly longer than the contactor hold-off delay produced by capacitor C.2 and resistor R2q_, so that rapid changes from motoring to braking and back again do not interfere with the oueration of the field reset circuits. The diodes D_„ andD D D__ and the resistor R2gg also contribute by allowing capacitors Ct, . and C^„ to discharge quickly after selecting braking ready for the next change into motoring. An extra function of these components occurs on start up. In neutral transistor Pg is on and holds transistor N 2 on via the resistor R21g . This holds the contactor in its braking condition and produces a small field current. If the vehicle is moving transistor P ,. will turn on transistor 2„ and prevent either forward or reverse being selected.U R E | CLAIMS1. A control system for a d.c. motor comprising control means for varying the connections of the motor armature winding and/or field winding so as to enable the motor to operate in a plurality of different modes, and speed interlock means for preventing operation of said control means to change the motor connections . from at least one mode to at least one other mode whilst the motor is running characterised in that said interlock means is sensitive to the voltage across the armature winding of the motor and means are provided for supplying a field current to the field winding when said interlock means is required to be operative.2. A control system as claimed in claim 1 further charac¬ terised in that said interlock means includes a rectifier BRl connected to the armature and a means sensitive to the d.c. output of the rectifier.3» A control system as claimed in claim 2 .in .which said means sensitive to the d.c. output of the rectifier includes an oscillator TJ. , Rm.Q tc--ιa isolating trans¬ former T_ , T2 having its primary vinding connected to the oscillator and a detector circuit ^η , D,-2, C_2, P f- connected to the secondary winding T„ of the isolating transformer. k m A control system as claimed in any preceding claim characterised in that the means for supplying current is required to be operative supplies a fixed length current ■Dulse of predetermined magnitude thereto.BURE4 | CAMPBELL G; LUCAS INDUSTRIES LTD; LUCAS IND LTD | CAMPBELL G |
WO-1979000367-A1 | 1,979,000,367 | WO | A1 | XX | 19,790,628 | 1,979 | 20,090,507 | new | C08G79 | C08K5, C08L85 | C08G79, C08J3, C08L85 | C08G 79/02B, C08J 3/07+L85/02, C08L 85/02 | POLYPHOSPHAZENE AQUEOUS SUSPENSIONS AND HALOGEN-FREE COPOLYMERS USEFUL THEREIN | Aqueous dispersions of polyphosphazene polymers are prepared by dissolving the polymer in a volatile organic solvent, then combining with water under agitation and heat to evaporate solvent leaving the aqueous dispersion for use in coatings and impregnations. Nonionic or anionic dispersing agents improve stability, preferably phosphate esters of polyoxyethylene for fire-retardancy. Halogen-free polyphosphazene copolymers having a phenoxy group and either a phenyl phenoxy or naphthoxy group or both are provided as aqueous dispersions for coatings on metal or glass with superior adhesion and freedom from halogen fumes when subject to burning. Preferred copolymers have molecular weight of 100, 000 or more, ratio of phenoxy groups to the other groups of 30:70 to 95:5 and up to 10% of the groups being such as methoxy phenoxy, vinyl phenoxy or allyl phenoxy, and are mostly amorphous with Tg of at least O` C. | HAZE E UEOU SUSPENSIONS AND HALOGEN-FREE COPOLYMERS USEFUL THEREINDESCRIPTIONTechnical FieldThe present invention relates to polyphosphazene polymers and copolymers in aqueous suspension, and partic- ularly to certain halogen-free polyphosphazene copolymers which are particularly adapted to form aqueous suspensions which will air dry to form continuous coatings.Background ArtPolyphosphazene polymers and copolymers are known, but these have not been provided in aqueous suspension which is a particularly desirable form when it is desired to use the polyphosphazene for a coating or impregnating purpose. Most polyphosphazene polymers are not suited for coating application and this may partially account for the fact that coating concepts have received little attention by the art. It is particularly desired to provide such aqueous suspensions and coating compositions containing the same using halogen-free polyphosphazene copolymers which are highly soluble in organic solvents, and exhibit good film properties and which coalesce at low temperature. The absence of halogen eliminates the generation of halogen-containing fumes when the coatings are subjected to burning. Better adhesion to metal and glass substrates is also obtained. Disclosure of InventionIn accordance with this invention, a polyphospha¬ zene polymer or copolymer, and preferably a halogen-free polyphosphazene copolymer containing at least one phenoxy substituent and a second substituent selected from phenyl phenoxy, naphthoxy, and mixtures thereof, is dissolved in a volatile organic solvent to form a solvent solution. This solvent solution of polyphosphazene polymer or copolymer is dispersed in water (containing a surfactant where suspension stability is desired) and all or a portion of the volatile solvent is removed by vaporizing the same with heat. This provides an aqueous polymer suspension which is useful as a coating composition. The preferred copolymers are mostly amorphous and have a T of at least 0°C. which confers desirable physical characteristics. So long as the T is not excessive, coatings of the aqueous suspension will air dry to form a continuous film. Relatively high T is a feature of this invention, and when the T is too high for air dry, baking can be used. While useful results can be obtained regardless of how high the T is, it is preferred that the T not exceed 50°C. to maximize the flexibility of the film.T denotes the glass transition temperation of a polymer and is a well known physical parameter.While polyphosphazene polymers and copolymers are broadly known, the specific halogen-free polyphosphazene copolymers described above are new and confer better film properties than the known halogen-free materials. Superior hardness, solubility, and impact resistance are particularl contemplated. These new copolymers are thus a feature of this invention.Referring more particularly to the new copolymers, the production of polyphosphazene polymer is a matter of common knowledge. In this invention, the halogen groups in the polymer obtained by polymerizing phosphonitrile chloride trimer are replaced with phenoxy groups in part and most of the balance of these halogen groups are re¬ placed by phenyl phenoxy, naphthoxy, or mixtures thereof. Any remaining halogen groups, up to 10% of the initially present halogen groups, may be replaced by diverse groups, such as methoxy phenoxy groups, vinyl phenoxy groups, allyl phenoxy groups, and the like. 4-phenyl phenoxy is the preferred phenyl phenoxy group, and 2-naphthoxy is the preferred naphthoxy group. The ratio of the phenoxy groups to the other groups in the final copolymer may range from 30:70 to 95:5, but the two types of substituents are preferably in a ratio of 40:60 to 80:20. Particularly with the phenyl phenoxy group, flexibility is maximized with a ratio of 60:40 to 80:20. The copolymers which are preferred for use herein are of high average molec¬ ular weight, normally 100,000 or higher. Molecular weight is measured by gel permeation chromatography and low molecular weight fragments are present in the mix¬ tures which are produced.The volatile organic solvent is subject to consid¬ erable variation for it will be appreciated that it is only a temporary carrier and all or most of this solvent is vaporized out of the final aqueous suspension. Aro¬ matic- hydrocarbons, such as toluene or xylene, are partic¬ ularly preferred for these have reasonable solvency capacity for the polyphosphazene polymer or copolymer, and they are of low cost and not unduly toxic. Relatively water immiscible solvents are preferred, but are not essential.The solvent solution of polymer is preferably added to the water with the addition being in increments with removal of solvent by vaporization either after addition is complete and the particle size established by agitation, or as the addition continues. Some of the water may also be removed to increase the solids content. In these ways, the solids content of the suspensions which are produced may exceed the solids content of the solvent solution which is used to produce it. It is also possible to add the water to the solvent solution, but this makes it more diffi¬ cult to obtain a uniform suspension.One can produce the suspension in water with continual agitation and use this suspension before it settles. On the other hand, suspension stability is frequently import¬ ant, in which case surfactants, and especially nonionic and anionic surfactants, may be incorporated in the water to provide a more stable suspension. The proportion of the surfactant in the aqueous medium is conveniently from 2-10% by weight, preferably from 3-8%, based on the weight_ OMPI■ - of the copolymer to be added. Usually, thickeners may also be present in the water since it is known that these can help to stabilize suspensions of water immiscible materials and to provide appropriate viscosity for coating. Carboxy methyl cellulose will illustrate an appropriate thickener.A mixture of sodium lauryl sulfate and cetyl alcohol provides a very effective surfactant action, especially when ultrasonic agitation is used to provide the finest particle size. Much of the solvent and part of the water may be removed after agitation to provide the desired solids content, as by heating under vacuum, preferably in a rotary evaporator. From the standpoint of the fire retardancy, the preferred surfactants have the formula: where x and y are each at least 1 and total 3, Z is selected from hydrogen and alkali metal, n is a number from about 5 to about 60 and R is a hydrocarbon- substituted phenyl group in which the hydrocarbon substit¬ uent contains from 6-22 carbon atoms. The preferred hydro carbon substituent is a saturated hydrocarbon containing from 8 to 9 carbon atoms. The phosphate acids and salts are of about equal value, sodium and potassium salts being illustrative. An illustrative material used hereinafter is Wayfos M-60 (Wyandotte Chemical Company) which consti¬ tutes a preferred commercially available phosphate ester of the general type described above. In this product, and with reference to the structural formula, R=nonyl phenol; n=10; x=l, y=2, and Z=H.It is stressed that the polyphosphazene copolymers are poorly soluble in organic solvents. As a result, it is essential in order to have sufficient solids content for normal coating use in the absence of excessive-ftU , 7A . vicsosity, to employ the polyphosphazene polymer in a suspension form, and water is of special value in this capacity. At least 15%, preferably at least 207„ solids is preferred, and from about 30% to about 40% gives best results.It is particularly pointed out that the presence of a relatively small proportion of the phenyl phenoxy or naphthoxy group considerably improves the flexibility of the polyphosphazene copolymer. Thus, in a coating pigmented with a 1:1 ratio of titanium dioxide pigment: copolymer, the phenoxy ho opolymer failed a 1/4 inch mandrel flexibility test while, with a ratio of from 20% to 407o and 4-phenyl phenoxy or 257o to 60% 2-naphthoxy groups in the phenoxy copolymer, the pigmented coatings passed a 1/8 inch mandrel flexibility test. This is particularly surprising for the 4-phenyl phenoxy copoly¬ mer where the presence of this group also increased the hardness of the coatings. When the phenoxy group is also replaced, as in the 4-methoxyphenoxy-4-phenyl-phenoxy copolymer, -flexibility is very poor.The invention is illustrated in the following examples which show the production of an appropriate polyphosphazene copolymer, its provision in toluene sol¬ ution, the production of a typical water suspension and the formation of a film therefrom.All parts herein are by weight unless otherwise stated.Best Mode of Carrying Out the InventionExample 1 Phosphonitrile chloride trimer in a sealed container is heated at 250°C. for 30 hours to obtain a solid poly¬ phosphazene polymer. The polymer is placed in a dry nitrogen atmosphere and charged with 3 parts of toluene to dissolve each part of polymer. The polymer dissolves at room temperature to provide a solution.In a separate flask charge 650 ml diethylene glycolOMPI dimethyl ether, 23 grams sodium metal, 0.94 moles of 4-phenyl phenol and allox-7 to stand overnight to provide sodium 4-phenyl phenylate.In another flask mix 650 ml diethylene glycol dimethyl ether, 23 grams sodium metal and 0.94 moles of phenol to provide sodium phenylate.Charge the sodium 4-phenyl phenylate solution to the polyphosphazene polymer solution and heat to 100°C. and then charge the sodium phenylate solution and heat to 125°C. for 24 hours. The two sodium derivatives are present in equimolar proportion and in stoichiometric balance with the chloride in the polymer. Sodium chloride is the by-product of the reaction. The temperature is then reduced to 115°C. and held for another 24 hours. The reaction product is poured into 4 liters of methanol tp precipitate a copolymer in which the poly¬ phosphazene is substituted with a 50:50 ratio of phenyl and 4-phenyl phenoxy substituents, and this copolymer is removed and dissolved in 1 liter of tetrahydrofuran to provide a solution which is mixed into 4 liters of a water and methanol mixture (50/50) to precipitate the substituted polyphosphazene copolymer and this process of dissolution and precipitation is repeated 4 or 5 times to obtain a reasonably pure copolymer which is dissolved in toluene to form an 11% by weight solution. The sodium chloride by-product is removable by water washing alone,, but the repeated precipitation procedure used in this example also removes low molecular weight fractions, and is preferred for that reason. Use a solution of sodium lauryl sulfate and cetyl alcohol (50:50) in deionized water containing 3% thereof based on the weight of the copolymer to be added and add the copolymer solution to enough water to provide 3 parts of water per part of added copolymer with vigorous agitation to provide a dispersion. The toluene is vola¬ tile so heat is applied and the toluene is distilled, away to provide an aqueous dispersion of apparently solid polymer particles (2-3 micron particle size) having a solids content of about 25%. Industrial Applicability The dispersion product is a mildy white suspension. The suspension is drawn down on an aluminum panel and dried at room temperature to produce a continuous film. The film is soft, opaque and generally white in color.The polyphosphazene copolymer is itself fire resist- ant and the film under consideration is halogen-free. Best Mode for Carrying Out the Invention (Continued)In preferred practice the vigorous agitation is supplied using an ultrasonic call disruptor for 5 to 15 minutes using 150 watts to operate the ultrasonic agita- tor. Average particle sizes of less than about 1 micron are consistently obtained in this way.The preferred procedure for dispersing the polymer solution is to add a solution of copolymer in toluene (140 g, 7.5% by weight) to a solution of the surfactant (6% on the basis of the dry copolymer) in deionized water. The mixture is blended at high speed for 30 minutes in a high speed blender and is then transferred into a 2 liter beaker and further dispersed with an ultrasonic cell dis¬ ruptor for 5 to 15 minutes at 150 watts. During the soni- fication, periodic microscopic observations are made to determine the particle size. Sonification is stopped when no significant change in particle size is noted. In most cases dispersions are allowed to stand overnight at room temperature. If there is no separation of immis- cible layers, the dispersion is put into a 2 liter flask along with 6-8 drops of a defoamer, toluene, and portions of water are removed by distillation under reduced pres¬ sure (60-70 mm of mercury) . Best results are obtained by using a rotary evaporator. The defoaming agent can be constituted by any commercial defoamer and is merely used as a matter of convenience since foam production does not prevent the formation of a- useful suspension.Example 2 Poly(dichlorophosphazene) 440 g (7.1 moles) is dissolved in 3200 ml of dried and distilled toluene in a 5 liter flask under a nitrogen blanket. Complete dissolution of the polymer is achieved in 24 hours and the solution is transferred into a 24 liter flask fitted with a stirrer, reflux condenser, and an addition funnel. A solution of sodium-4-phenylphenoxide obtained by reacting 48 g (2.08 g-atoms) of sodium with 389 g (2.29 moles) of 4-phenyl phenol in 2600 ml of dried and dis¬ tilled diethylene gl col dimethyl ether is slowly added to the polymer solution over a period of 1 1/2 hours. The temperature is raised to 100°C,. and a solution of sodium phenoxide, obtained by reacting 143 g (6.23 g- atoms) sodium with 650 g (7.0 moles) phenol in 2600 ml dried and distilled diethylene glycol dimethyl ether is then added over a period of 1 1/2 hours. The reaction mixture is heated to 125°C. for 24 hours and to 115°C. for an additional 24 hours and then cooled to room temper¬ ature and poured into 16 liters of methanol to give a gummy solid. The polymer was purified by dissolving it in tetrahydrofuran and reprecipitating it into water (4 times) and methanol (2 times) . The polymer product is then cut into small pieces, and dried under vacuum at room temperature for two days followed by two additional days at 120°F. The intrinsic viscosity of the polymer is 1.3 dl/g in tetrahydrofuran at 30°C. The phenoxy and 4-phenyl phenoxy substituents are present in approxi¬ mately a 3:1 ratio and the phosphazene copolymer has aT of 17°C. and forms a continuous film upon coalescence g at room temperature.Using the commercially available phosphate ester surfactant Wayfos M-60 (Wyandotte Chemical Company), 133 grams of a 7.5% by weight toluene solution are added to_, _ l' i OM 400 grams.of water containing 0.6 grams of the phosphate ester surfactant. After completion of the sonic disper¬ sion and subsequent vaporization of the toluene and some of the water, a reasonably stable suspension containing 25% by weight of nonvolatile solids is obtained. The particle size is in the range of 0.5-1 micron and the suspension is substantially unaltered after storage for 2 weeks.OMPI lO | (received by the International Bureau on 29 May 1979 (29.05.79))WHAT IS CLAIMED IS:1. Water having stably suspended therein particles of polyphosphazene polymer or copolymer having a molecular weight of at least 100,000 and a T of at least 0°C. up to 50°C.2. A water suspension as recited in claim 1 in which said polyphosphazene polymer or copolymer is present in an amount to provide a solids content of at least 15%. 3. A water suspension as recited in any of claims 1 or 2 in which said polyphosphazene is a halogen¬ free copolymer having at least one phenoxy substituent and a second substituent selected from phenyl phenoxy and naphthoxy in a ratio of 30:70 to 95:5. 4. A water suspension as recited in claim 3 in which the two named substituents are present in a ratio of 40:60 to 80:20.5. A water suspension as recited in claim 4 in which a surfactant is present to stabilize the suspension.6. A water suspension as recited in claim 5 in which said surfactant is present in an amount of from 2-10%,, based on the weight of said polyphosphazene polymer or copolymer. 7. A water suspension as recited in claim 5 in which said surfactant has the formula:R -ξ-(0CH2CH2 (- OZ)y where x and y are each at least 1 and total 3, Z is selected from hydrogen and alkali metal, n is a number from about 5 to about 60, R is a hydrocarbon-substituted phenyl group in which the hydrocarbon substituent contains from 6-22 carbon atoms.8. A water suspension as recited in claim 7 in which said hydrocarbon substituent is a saturated hydro- carbon containing 8 or 9 carbon atoms. 9. A water suspension as recited in claim 4 in which the particles of polyphosphazene polymer or co¬ polymer have an average particle size of less than about 1 micron and are present in an amount to provide a solids content of from about 30% to about 40% by weight.10. A water suspension as recited in claim 1 in which a thickener is present to help stabilize the suspension and provide appropriate viscosity for coating.11. A process of producing the water suspension of any of claims 1 or 2, comprising dissolving polyphos¬ phazene polymer or copolymer in a volatile organic solven to form a solution, and combining said solution with water using agitation and heat to evaporate at least some of said solvent and produce a suspension of poly- phosphazene polymer or copolymer in an aqueous continuum.12. A process as recited in claim 11 in which said organic solvent is an aromatic hydrocarbon solvent.13. A process as recited in claim 12 in which said solvent is selected from toluene and xylene. 14. A process as recited in claim 12 in which said solution is added progressively with removal of solvent so that the aqueous suspension will have a higher solids content than the solution used to produce it.15. A process as recited in any of claims 12-14 in which some of said water is evaporated so that the aqueous suspension will have a higher solids content than the solution used to produce it.16. A halogen-free polyphosphazene copolymer useful in the water suspension of claim 1 having at least one phenoxy substituent and a second substituent selected from phenyl phenoxy, naphthoxy and mixtures thereof in a ratio of 30:70 to 95:5. 17. A polyphosphazene copolymer as recited in claim 16 in which the two named substituents are present in a ratio of 40:60 to 80:20, and the copolymer is mostly amorphous. 18. A polyphosphazene copolymer as recited in any of claims 16 or 17 in which the two substituents are phenoxy and 4-phenyl phenoxy.19. A polyphosphazene copolymer as recited in claim 16 in which the two substituents are phenoxy and 2-naphthoxy, these two substituents being present in a ratio of 75:25 to 40:60. | CHATTOPADHYAY A; ROSE S | CHATTOPADHYAY A; ROSE S |
WO-1979000377-A1 | 1,979,000,377 | WO | A1 | EN | 19,790,628 | 1,979 | 20,090,507 | new | G02B5 | null | G01B11, G01D5, G01H9, G01K1, G01K11, G01L1, G01L11, G02B6 | G01B 11/18, G01D 5/353, G01K 1/02C, G01L 11/02B, G02B 5/16C, G02B 6/14, G02B 6/28B10 | OPTICAL SENSING APPARATUS AND METHOD | A sensor for measuring stress, temperature, pressure, sound, etc. comprising an optical fiber waveguide (24 of Fig. 6), a light source (22) which injects light (30) into one end of the waveguide, a deformer (27) contacting and deforming the waveguide to cause light to couple from originally excited modes to other modes, and an optical detector (29) to detect the change in light coupling caused by deformation of the waveguide. | DescriptionOptical Sensing Apparatus and MethodTechnical FieldThis invention relates to a device which responds to an external stress. It employs an optical signal to detect the change in mode-coupling properties of an optical (including infrared, visible and near-ultra¬ violet) waveguide when subjected to a mechanical de¬ formation caused by external stress. We call this device a stress sensor even though it can be used to measure temperature and strain in addition to force, weight, pressure and sound intensity.Background ArtDynamic pressure sensors for use in air, i.e., microphones, and in water, i.e., hydrophones, for the detection of sound pressure variation have been mainly of the piezoelectric, electrostrictive and magneto- strictive type. Depending on the application and its requirements, i.e., bandwidth, ruggedness, operation in varied environments, etc., some types of sensors are capable of detecting, pressures less than 10 -9 bar,(1 n bar) . Static sensors are capable of pressure measurement ranging from less than a nanobar to mega- bars. With these usual types of detectors it is difficult to obtain small size for use in arrays, to achieve protection from electrical noise and crosstalk and to obtain satisfactory operation in hostile environments. Disclosure of InventionThe stress sensor disclosed here overcomes many of the disadvantages of the sensors presently in use. This device has a sensitivity which equals or exceeds those discussed above and depending on the environ¬ mental conditions has many advantages including: 1) freedom from electrical noise and crosstalk; 2) with¬ standing of high and low temperature environments (e.g., temperatures ranging from less than 0°C to more than 700°C) ; 3) withstanding of corrosive environ¬ ments; 4) having the d-c to wide band capabilities required of multi-signal sources; 5) capability of being easily coupled to fiber optic links for long distance remote sensing; 6) lightness of weight; 7) ruggedness; 8) small size.Some of the suggested uses of our stress sensor are a) as a hydrophone which may be used singly or in an array at shallow as well as extreme depths of the ocean; b) an opto-acous ic microphone for high sensi- tivity wide band capability; c) a static pressure sensor able to operate over large pressure ranges yet capable of long lifetime under pressure cycling; d) an optic barometer and manometer; e) a displacement or proximity sensor for measurement of displacements less than 1A, (10 —8 cm) ; f) an optic seismic detector; g) a flame detector based on displacement; h) a thermometer; i) a pressure switch; and j) an optical switch. The use of the stress sensor is especially desirable for the above application where extreme environments exist and/or elimination of electrical wire-type transmission lines is desirable since this permits elimination of electromagnetic interference while allowing for considerable reduction in detector s ze.To better understand this invention we introduce some fundamental ideas about mode propagation in optical waveguides. Optical waveguides can be planar or cylindrical. The small diameter cylindrical optical waveguides are generally called fibers and usually consist of two concentric dielectric cylinders, the core and the clad. As long as the dimensions of the optical waveguide in which the light signal travels are much larger than the light wavelength, the light can be considered as propagating in the form of rays or beams which are reflected or transmitted at the various boundaries of the waveguide. Even though this ray description is not exact, it is frequently used since it is more intuitive than a wave description.The geometry of the core and clad of the waveguide, as well as the refractive indices of the core, clad and the surrounding media define the boundary conditions which determine the possible paths that a wave or ray may take in the waveguide. The specific paths consist¬ ent with these boundary conditions are called modes. Which modes are excited, i.e., in which modes light propagates, depends upon the way that light is injected into the waveguide. Individual modes are distinguished by the different angles their ray paths make with the waveguide axis.The ray picture of the modes is further illustrated in Figures 1-5 where we have shown several of the mode types important to our discussion of the invention. We have shown the bound core, refractive, leaky, and clad modes schematically in Figures 1-4 respect¬ ively and have shown the relation between a high and low order mode in Figure 5. In Figures 1-5 the refractive indices of the core3. clad 5, and surrounding medium 7 are n , n -, n ' co cl m respectively.To maintain most of the light guided within the waveguide core, the refractive index of the core is made larger than the refractive index of the clad, that is, nco > ncl._. in Fig3ures 1-5.As shown in Figure 1, a bound core mode 9 is represented by a ray propagating at such an angle with respect to the waveguide axis that it is totally internally reflected at the core clad interface. The propagation angle is less than some critical angle determined by the core and clad refractive indices. The light which propagates at angles greater than the critical angle with respect to the axis can: a) As illustrated in Fig. 2, be incident at the core-clad interface at such an angle that it is partially refracted and then is again partially refracted at the interface between the clad and the surrounding medium where only the refractive paths have been shown. Such a mode is called a refractive mode 11.b) As illustrated in Fig. 3 for the case of a cylindrical waveguide or fiber propagate in a skew path, i.e. such that the ray representing the path never passes through the axis of the fiber. Such a mode is called a leaky core mode 13 but can be trapped in the fiber for some distance before its power is radiated away.c) As illustrated in Fig. 4, propagate at such an angle that at the core clad interface it is partially refracted and partially reflected and at the clad surrounding medium interface it is totally internally reflected. For the sake of clarity, only the part of the ray 17 which is partially reflected is indicated. Such a mode is trapped in the core clad system and is called a clad mode 15.The bound core modes may also be further charac¬ terized by the angle at which they propagate with respect to the waveguide axis. As this angle increases from zero to the critical angle, these modes change from lower order modes to higher modes. This is shown in Fig. 5 where the mode labeled 21 is a higher order mode than the mode labeled 19. The total number of possible bound core modes increases as the diameter of the core increases and as the refractive index difference between the core and clad increases. If the diameter of the core is small enough, and the refractive index difference between the core and clad is small enough, then only one mode can be supported in the waveguide. Under this condition, the waveguide is called a single mode waveguide, in contrast to the ease of a multimode fiber, where up to several thousand modes can be supported. The invention disclosed here is based on our dis¬ covery that extremely small deformations of the wave¬ guide will cause significant amounts of light to couple from the originally excited modes to other modes and that by monitoring the intensity of light in one or more groups of modes but not the total light in 'the waveguide, a device highly sensitive to waveguide deformation and thus to surrounding pressure, tempera¬ ture, etc. can be made. The main components of the sensor are the source system, the sensing system, and the detection system. The source system comprised of (a) an optical source which generates light, (b) a means of injecting the light into the modes desired, and (c) in some embodiments a transmitting waveguide. The means for appropriately injecting the light into the modes will be described later on in terms of (a) the injection angle of light from the optical source into the waveguide, and (b) removing the energy from specific modes just before the sensing system. The sensing system comprised of (a) the region of a wave¬ guide section which is deformed and called the sensing region, (b) a device which amplifies the effect of applied stress, called the deformer . The detection system consists of (a) a means for selectively col- lecting the light from one or more groups of modes which will be described later on, and (b) an optical detector for measuring the light from these modes.We have invented a stress sensor consisting of at least one optical (including infra-red, visible and near ultra-violet) waveguide, having at least two groups of modes denoted as A and B , each group containing at least one mode. Light emitted from an optical source is injected into the waveguide. Stress on the waveguide results in a change in deformation of the waveguide. This change in deformation introduces a change in the coupling of light among the modes; in this way some of the light is redistributed among these modes. The light power in B modes, measured using an optical detector, is a sensitive measure of the extern- al stress.Preferably the stress is transmitted to the wave¬ guide via a device which we denote as a deformer and which enhances in some region of the waveguide the effect of the external stress on the change in deform¬ ation of said waveguide.When the sensor is to be used to measure tempera¬ ture the preferred embodiment involves at least two materials, one of which could be the waveguide itself, with dissimilar expansion coefficients which are con¬ figured to produce a deforming stress on the waveguide upon a change in temperature of the region surrounding the sensor.When the sensor is used to measure pressure the preferred embodiment comprises using an enclosure which converts external pressure changes into deformational changes of the waveguide.In another embodiment of the sensor the sensitive region of the waveguide is predeformed and the applied stress to be measured causes a change in the amount of this deformation.In a preferred embodiment of this invention the waveguide is an optical fiber. Preferably when a fiber optic waveguide is used the A modes are chosen to be higher order bound core modes or leaky core modes. Brief Description of DrawingsFig. 1 shows one bound core mode in an optical waveguidFig. 2 shows one refractive mode in an optical waveguidFig. 3 shows one leaky core mode in a fiber optic wave¬ guide.Fig. 4 shows one clad mode in an optical waveguide.Fig. 5 shows two bound core modes in an optical wave¬ guide.Fig. 6 is a schematic diagram showing a source system, sensor system, and the detector system.Fig. 7 is a schematic diagram showing stripping of clad modes and sensor system.Fig. 8 shows coupling of a leaky core mode to a clad mode by action of a deformer.Fig. 9 shows coupling at a bound core mode to a clad mode by action of a deformer.Fig. 10 shows a sensing system with an enclosure.Fig. 11 shows a sensing system having a cylindrical enclosure.Fig. 12 shows a sensing system for measurement of temperature.Fig. 13 shows a multi-piece deformer with waveguide attached at two points.Fig. 14 shows a one piece deformer with waveguide attached at two points.Fig. 15 shows a schematic diagram showing a predeform¬ ed fiber.Fig. 16 is a diagram showing source system exciting a bound core mode of sensing system.Fig 17 is a diagram showing source system exciting- a'JOMPIS ΛΓATI leaky core mode in the sensing system.Fig. 18 is a schematic diagram showing generation of a a leaky core mode from a bound core mode by necking down the diameter of the optical fiber. Fig. 19 shows a near field detection system.Fig. 20 shows a far field detection system.Fig. 21 shows a method for detection of clad modes.Fig. 22 is a schematic showing coupling of a clad mode of one fiber to a bound core mode of another fiber.Fig. 23 shows a multi-sensor system with a return fiber to the detector from each sensor. Fig. 24 shows a multi-sensor system with return fibers coupled to a common fiber. Fig. 25 shows a multi-sensor system where the common return fiber is coupled to the source system fiber. Best Mode for Carrying Out the InventionA stress applied to an optical waveguide will cause power to be coupled among the modes of the wave¬ guide. We have discovered that this fact can be used to make an extremely sensitive stress sensor. This sensor consists of three parts: the source system, the sensing system, and the detector system which are described with their preferred embodiments below. It is to be noted that by proper design of the sensing system the stress sensor may be used as a device to measure static pressure, dynamic pressure, temperature, weight displacement or parameters which may be convert¬ ed to a stress by any means.Referring to the drawing, one embodiment of our stress sensor is illustrated in Figure 6. The princi¬ pal elements of the system comprise a light source system 23, a sensing system 28, and a detection system 29. As illustrated schematically in this Figure, light 30 from an optical source 22 is focused by a' lens 20 into an optical fiber called the transmitting waveguide 24 which has a core 3 and a clad 5. The light is injected such that most of the light energy is in the bound core modes called A modes and substan¬ tially less energy is in the clad modes called B modes. One core mode 9 is shown for illustration. Over some short section within the enclosure 25 a mechanical deformation is applied to the waveguide by the deformer 27, which is in the form of two steel pieces having corrugated like surfaces with interleaving ridges form- ing a vise which would be used to squeeze and thus deform the fiber. For the sake of clarity in the drawings the deformers are shown spaced from the wave¬ guide. It will be appreciated that in is contact during deformation. The deformation causes the light to couple among the various core and clad modes of the fiber. One clad mode 15 excited by the action of the deformer is shown for illustration. The intensity of the clad modes increases at the expense of the core modes.We have discovered that a very small strain or deformation of the fiber can be detected by monitoring the intensity of the light in the clad modes with a detector 32. The deformation of the fiber is related to the applied pressure on the deformer and we have discovered that the configuration shown schematically in Figure 6 becomes an extremely sensitive static or dynamic pressure sensor, with modification of the enclosure. The sensor may also be of such an arrange¬ ment as to respond to a displacement, strain or temperature rather than pressure or sound intensity.Source SystemIn all embodiments of this invention a system is provided to inject light into the sensing system of the •stress sensor. This source system consists of a light source, a means of transmitting the light to the sensing system and a means of selectively exciting the modes of the sensor waveguide.Three embodiments of the source system are de¬ scribed here to define terms and to clarify the follow¬ ing discussion. The first and simplest embodiment consists simply of a light source and appropriate optics to inject light into the waveguide of the sensing system. The second embodiment consists of a light source and appropriate optics to inject light into the transmitting waveguide. The transmitting waveguide and the waveguide of the sensing system are, in the embodiment, parts of the same waveguide. A device to remove or strip i.e., remove energy from the B modes of the waveguide before it enters the sensing system may be present. The third embodiment is identical to the second embodiment with the exception that the transmitting waveguide and the waveguide of the sensing system are not parts of the same waveguide and a coupler is employed. The purpose of the coupler is to couple light from the transmitting waveguide to the waveguide of the sensing system and in some cases to physically join the transmitting waveguide to the * sensing system.The light source can be any device for generating light including incoherent and coherent sources. For efficient light coupling to waveguides it is preferred that the device have a high radiance. Suitable devices would include lasers, light emitting diodes, arc lamps and filament lamps. For high reliability, low cost, small size and for coupling to a multimode waveguide, a light emitting diode is preferred. For coupling to a single mode waveguide, for ease of control of the modes excited or where high light intensity is desired a laser is preferred such as the argon laser of exam- pies.5, 6, 7 and 8. For low cost a semi-conductor laser is preferred. For high intensity a neodinium laser is preferred.The light source can be either of the continuous wave CW types, or it can be pulsed. A pulsed optical source is preferred when many sensing systems are to be used along an optical waveguide. In this case the detected light from different sensing systems has different propagation times and therefore, it can be separated in time. The minimum resolvable distance between sensing systems and/or the maximum transmissible data rate through a fiber is limited by the width of the light pulses and the dispersion of the transmitting waveguide. The light source capable of emitting narrow pulses of the order of 1 nsec or a fraction of a nano¬ second wide is a semi-conductor laser such as GaAs or InPAsGa lasers and are preferred when maximum band width is required.In the simplest embodiment of this invention, the light source injects light directly into the waveguide of the sensing system. If it is desirable to locate the sensing system in an inaccessible or a hostile environment, e.g., at high pressure, temperature, etc. or to avoid the presence or necessity of electrical devices near the area where the sensing system is located, it is preferred to transmit the light from source to sensing system by an optical fiber waveguide. In general for efficiency of injecting light it is preferred that the transmitting fiber have a core di- ameter and a numerical aperture less than or equal to that of the -waveguide in the sensing region. However, in certain situations increased sensitivity is attained by not following this teaching. For example if one wishes to inject light into leaky core modes of the sensing waveguide the numerical aperture of the sensing waveguide should be less than that of the transmitting fiber. In practice it may be part of the same or an identical fiber. If a low cost sensor is desired, a multimode step index fiber is preferred because of its relatively low cost and because it can be used with low cost LED light sources. Other reasons for pre¬ ferring multimode waveguides is that coupling of light between them is relatively easy and low cost connect¬ ors can be employed. This type of waveguide suitable for static stress measurements as well as many dynamic measurement applications. When the transmit¬ ting fiber is long and when a high data rate is main¬ tained utilizing pulse techniques a graded index fiber is preferred because of its greater band width. This fiber also can be obtained with a relatively large core to facilitate coupling between waveguides and is suitable for use with LEDs, as well as with lasers. If the greatest dynamic frequency range of stress signals is to be measured or in the case of closely spaced sensor arrays where the data rate will be high, a single mode fiber is preferred.In many embodiments of this invention stress applied to the waveguide in the sensing system couples light from one mode or group of modes call A into a second mode or group of modes called B . The B modes are ultimately detected by the detector system.In an embodiment of the invention light is coupled into the waveguide of the sensing system with both types of modes, A and B, excited. To improve sensiti¬ vity it is preferred to make the power in the B modes less than 1% and preferably less than .1% of the power in the A nodes before entering the waveguide of the sensing system. This may be accomplished by injecting light directly into the waveguide of the sensing system or into the transmitting waveguide at such an angle or range of angles with respect to its axis that no B modes are excited. If the transmitting waveguide is perfect, and subject to no deformations, the light will remain in the original excited modes. If the waveguide is not perfect some light will invariably couple to the B modes which must then be stripped. If the B modes are clad modes, they may be stripped as illustrated in Fig. 7 where 33 is the stripper and 35OMPI WIPO is the stripped clad mode. For example, stripping may be accomplished by immersing the waveguide in a liquid having the same or higher refractive index or by coat¬ ing the waveguide with an absorbing jacket of higher index of refraction. If the B modes are leaky modes they can be attenuated by employing a suitable length of transmitting fiber to attenuate these modes. The suitable length must be determined for each transmit¬ ting fiber and different light injecting conditions. if the B modes are certain types of bound core modes, they may be stripped by different means, depending on their order. If they are high order modes they may be stripped by employing a fiber section with a decreased core diameter. This will convert these high order B modes to leaky, clad or refractive modes depending on the type of waveguide, which modes will then be attenu¬ ated by a suitable length of reduced core diameter fiber or by stripping. As an example of such an embodi¬ ment a multimode fiber is considered, which can support few core modes, e.g., eleven. Light is injected into these eleven bound core modes. Before the deformer the fiber is necked down, i.e., a small section of the fiber is heated and stretched so that a neck is formed in which the fiber diameter- decreases slightly and then increases to its previous value. If the thinner fiber can support only ten modes, the light from the eleventh mode would couple to clad modes and it can be stripped before the deformer. Next as the fiber diameter increases to its previous value, the eleventh mode can be supported again. In this case all the light would propagate in the ten modes, or modes A, while the eleventh mode, or mode B, would be dark. If the B modes are low order modes, they may be stripped by suitable design of the fiber core. For greate -16-effectiveness it is preferred that the stripping of B modes be done as close to but ahead of the deformer as is practical. In practice the stripping could be done within the physical structure of the sensing system. To inject light into the A modes of the waveguide of the sensing system the simplest embodiment as in Fig. 16 where the A modes are bound core modes or in Fig. 17 where the A modes are leaky core modes is when the light is injected directly from the light source 79 employing suitable lenses and apertures 81 so that light enters the sensing waveguide only at angles that result in excitation of the A modes.In a second embodiment a transmitting fiber is used where the simplest arrangement would have the sensing waveguide be a part of the transmitting wave¬ guide and stripping is performed as described above to eliminate any B modes. A third embodiment would employ a coupler having suitable lenses and apertures and treating the transmitting fiber as the light source of the first embodiment described above. If the modes excited in the transmitting fiber correspond to the A modes for the waveguide of the sensing system a simple coupler may simply butt the two waveguide ends together. To improve the coupling efficiency it is preferred that index matching material be used between the two waveguide ends. Depending on the desired sensitivity and on the type of transmitting and sensing waveguides employed, different types of A modes are preferably excited. For most applications it is preferred that the A modes be core modes because of their lower attenu¬ ation than clad or refractive modes. We have found that light from high order core modes couples to clad modes more easily due to deformation than that from low order modes. Thus if the B modes are to be clad modesf OMPI it is preferred that the A modes be high order core modes which are excited by injecting light into the sensing waveguide at angles with respect to its axis near the critical angle. Included in the high order core modes are bound core and leaky core modes. If the A modes are to be transmitted a large distance, i.e., greater than 10 meters, it is preferred that the A modes be bound core modes due to their low attenuation. The leaky core modes can be excited by using the following techniques:(a) the light from an incoherent light source is coupled into the waveguide by a high numerical aperature microscope objective;(b) the colli ated light from a laser is coupled into the waveguide at an angle outside the numerical aperture of the waveguide;(c) the light from a laser is incident from the side of a tapered core section of a fiber immersed in a fluid whose index of refraction is higher than that of the waveguide core;(d) bound core modes may be converted to leaky core modes by decreasing the core diameter of the wave¬ guide.Sensing System The sensing region is a section of an optical waveguide arranged in an enclosure in such a fashion that an external stress will cause it to be deformed. Preferably a device we call a deformer is present whose purpose is to enhance the deformation resulting from a given external stress. In the most general case the deformer is any object or group of objects which apply a stress to the waveguide. The design of the deformer depends on the parameter to be measured and several embodiments are discussed below. One embodiment of this sensing system is shown in Fig. 10 and Example 8. The deformer is made of two pieces, 27. The upper piece, is firmly connected to the enclosure 43 by support 42. The lower piece is attached to an elastic membrane, 45. When either a static pressure or dynam¬ ic time varying pressure (sound wave) reaches the membrane, it deflects pushing the lower deformer piece, toward the upper deformer piece, thus deforming the optical fiber 1 which is held against the ridges of the deformer.In another embodiment of the invention as shown in Fig. 11, the enclosure is a cylindrical flexible outer jacket, 53. The deformer is composed of two half-cylindrical solid parts, 51, which when a pres¬ sure external to 53, is applied, move toward each other to deform the optical waveguide. Region 49 is a fluid space which is not at the external pressure and thus allows a net force to be exerted on the deformer.In many embodiments of this invention the sensor detects a displacment of the deformer pieces relative to one another which sets up a stress in the fiber and thus causes a deformation. Depending upon which embodiment of this invention is used, the displacement can be caused by different effects either singly or simultaneously. In each case, however, a force must be applied to the deformer to displace it. In one embodiment the side of the deformer away from the wave¬ guide, but not the waveguide itself, is exposed to. a region whose pressure one wishes to measure. The force applied to the deformer, which is pressure timesOMPI exposed area of deformer, causes the deformer to dis¬ place deforming the waveguide. In this embodiment we have a pressure sensing device. This can be used for example in altimeters, for static pressures and in hydrophones for dynamic pressures. If one part of the deformer is connected to an object which is dis¬ placed, then a displacement sensor is attained. In another embodiment, a weight placed on the deformer causes' displacement. In this case the sensing element is a weight scale. In another embodiment, one part of the deformer is attached to a bi-metallic strip or other system with two materials with dissimilar thermal expansion coefficients which, when the temperature changes, exerts a force on the deformer and the device becomes sensitive to temperature. If desired a combination of effects can be detected. Such a sensor is illustrated in Fig. 12. The material of the deform¬ er pieces 55 and 57 has a different expansion coef¬ ficient from the connecting posts 59. A change in temperature will cause a change in stress on the wave¬ guide due to the deformer pieces.The optimum configuration of the deformer depends on the geometry of the optical waveguide and the desired use of the sensor. For planar or cylindrical waveguides, the deformer could be as shown in Fig. 7 a simple set of two flat plates 31 between which the fiber is sandwiched. This configuration results in a large shear component in the strain deformation, on application of an external force. Stress amplification which enhances the sensi¬ tivity of the sensor, results when one of the two pieces has at least one ridge. The application- of ex¬ ternal forces in this case causes both shear and co pressional strain in the neighborhood of the ridge. The amplification is preferred when increased sensiti¬ vity is desired. The edges of the bottom plate can be rounded to keep strains to a defined region. When even higher sensitivity is preferred, the number of ridges should be increased, say to at least 5, as shown in Fig. 9, where 41 is the ridged piece and 39 is the flat piece.A different method of straining the optical fiber, which enhances the sensitivity, is achieved by flexural deformation. This is accomplished as shown in Fig. 6 by corrugating both plates 27 and sandwiching the fiber in such a way as to allow the ridges to interleave if the fiber is removed. Such a configuration is prefer- red when high sensitivity is desired. For the case of interleaving corrugations, the spacing of the corruga¬ tions may vary from as low as 0.1 millimeter to over one centimeter depending on the sensitivity desired. A variation of this deformer can be obtained by use of points instead of ridges.In another embodiment the deformer is, as shown in Fig. 13, composed of two half cylinders 61 and 63 joined along a portion of the flat face by an elastic material, 65. The fiber is fixed at two points 67 so that a change in separation of the cylinder halves will deform the fiber and cause coupling between modes A and B. In a similar embodiment depicted in Fig. 14, a cylinder 69 is partially split along a diame±er with a small wedge shaped region removed. The fiber is attached to the cylinder at points 67 or in another embodiment the fiber is wound around the deformer and held by friction and any opening and closing at the gap would result in a stress on the fiber causing■ OMPI y )*- WIPO ' coupling between modes A and B.The deformer could be a braided or a fibrous cable jacket surrounding the optical fiber. Such a deformer is preferred as more compact and convenient than plates. In this configuration longitudinal as well as transverse stresses on the cable would intro¬ duce flexural strains which in turn would cause mode coupling. In another possible configuration the deformer is of the form of a ridged cylinder and split sleeve, and the fiber is wound around the deformer in the shape of a solenoid coil. Such a configuration is preferred when long sensing elements should be utilized. As it was mentioned above, torsional strain can cause mode coupling. In this case the deformer is arranged to cause a twisting of the optical fiber. This is preferred in cases where small angular displacements need to be measured. In a more general case, any combination of the various deformers discussed above can be utilized. In other embodiments of the invention the optical waveguide 72, in the sensor is predeformed as is illu¬ strated in Fig. 15. This may be accomplished for example by irregularly curing a plastic jacket, or by inserting the waveguide into a predeformed but flexible jacket, or other such suitable means. In this embodiment the application of external stress changes the amount of deformation. The example illustrated in Fig. 15 is a strain gauge based on this embodiment. The strain between two points, 77 on the object 71 is measured by attaching the predeformed waveguide 72 via supports 73 and 75 to the object. A change in dist¬ ance between points 77 causes a change in deformation of the waveguide. The optical signal is brought into-BU EAITOMPI f*-, W1PO - -*V the waveguide via the transmitting fiber 74 and then goes to the detector via the receiving fiber 76.The enclosure must serve at least two functions. One is to maintain the relative positions of the de- former and the waveguide yet allow one part of the deformer to be free to move relative to the other part. A second function of the enclosure is to allow a net force to appear across the deformer parts so that they will move relative to each other -upon application of external stress. For example, when an external pressure is applied, the enclosure must be designed to insure that the pressure on one side of the move¬ able part differs from that on the other side so that a net force exists. When pressure is to be measured the enclosure can be designed to separate out the low frequency compon¬ ents from the high frequency components of the extern¬ al pressure by using appropriately designed ports which would pass low frequency pressure variations but not high frequencies and vice- ersa. A simple sensor configuration for pressure measurement is shown in Fig. 10. The enclosure is constructed with rigid walls 43. In one of the walls a flexible diaphram 45 is installed; which responds to the pressure dif- ferential that develops between the external medium and the fluid (gas, liquid, and elastomer) enclosed within the enclosure. In another wall a port 47 is installed which allows the fluid to be exchanged between inside and outside of the enclosure. The deformer 27 is attached to the flexible diaphram and responds within limits to any pressure difference between the inside and outside of the enclosure. The deformer used in this case is comprised of a set of corrugated plates 27 with one plate attached rigidly to a wall, the other is attached to the moveable di¬ aphram. The fiber 1 is passed thru the enclosure via small holes in opposite walls and then between the ridges of the deformer.Another useful configuration would have the fluid enclosure separate from but adjacent to the deformer. In these arrangements if the port were closed the system could be used to measure the total external pressures including both static and dynamic. With the 'port open this system will respond only to time varying pressures:,--.- for a given port size external pressure variation below some frequency depending on the port size may maintain an approximate equilibrium with the internal pressure resulting in near zero differential force on the deformer, and hence no change in deforma¬ tion of the fiber. The port can thus be used as a frequency filter. If one is interested in audible acoustic frequencies, the port should substantially attenuate frequencies below 1 Hz, while permitting the measure of high frequencies, that is, frequencies above 20 Hz. The upper limit of the sensor response is due to the elastic and inertial properties of the fiber, deformer, and enclosure configuration. The upper limit frequency cut off can be adjusted as desired. In the case of audible frequencies the maximum cutoff should be greater than 25 KHz.Depending on the configuration of the enclosure and the low frequency pressure transmitting device 47, the sensor could be made to operate as a barometer. In this case the port would be closed; or in another case the sensor with an open port could operate as a hydrophone or microphone.Under certain conditions itwould be preferable to have the waveguide, the source and the detector placed within the enclosure.We now consider the types of modes one can choose to use for various embodiments of the sensing system. If a fiber optic waveguide is used in the sensing system, light can propagate in three types of modes: bound core, leaky core, and clad modes. Monitoring of any one of these types of modes is a measure of the deformation of the fiber and thus the external stress can be found.In one embodiment light is injected into one or more of the above mentioned mode types and the light in at least one of the modes is monitored as a function of the waveguide deformation. However because of higher scattering at the clad surface, the light in the clad modes is attenuated more than the light in the core modes. Thus, it is preferred to inject the light in the bound core modes, which we label modes A in this case. On the other hand, the clad modes are dark, i.e., having very little light, and we label these modes B. Any small additional light coupled into the clad modes from the light in the core modes by a deformer would signifi¬ cantly change the light power in the clad modes. Under these circumstances, the detection of the light in the clad modes is preferred. When higher sensitivity is preferred, the clad modes should be stripped, before entering the deformer region as shown for example in Fig. 7. We have found that light from high order bound core modes couples to clad modes more easily due to deformation than that from low order modes. Thus, in order to enhance the sensitivity of the sensor, it is preferred that modes A be substantially high order bound core modes. In another embodiment the A modes are the bound core modes and the B modes are the leaky modes. In one such embodiment the leaky modes may be excited by necking down a section of the fiber by heating and drawing it out. This is shown schematic¬ ally in Fig. 18 where 85 is the necked down region of the fiber.In the case of a single mode fiber light can propagate in only one core mode, mode A. In this case modes B can consist of any mode different from mode A propagating forwards, or any mode propagating backwards.A multimode fiber, has higher input coupling efficiency than a single mode fiber. When the light source is a light emitting diode, the use of a multi- mode fiber is preferred.In a multimode fiber, modes A can also be some lower, order core modes, while modes B can be any com¬ bination of the higher order bound core modes. For example, light is injected into only the lower order (e.g. the first 10) modes of the sensing waveguide. The higher order modes to be monitored are kept dark. The light in these latter modes is enhanced by deform¬ ation of the waveguide which causes light to couple from the lower to the higher modes. The light inten- sity in the higher order modes is thus a measure of the deformation of and thus external stress on the optical waveguide.In another embodiment of the invention we have found that light from the leaky core modes can easily couple to the clad modes of an optical fiber. In practice the bound core and leaky core modes may both be excited as A modes with the clad modes being B modes but .it is preferred in this embodiment that the sensor consist of an optical fiber carrying lightOMPI WiPO « substantially in the leaky modes. After distortion of the fiber by the deformer, light in the leaky core modes is found to couple to the clad modes. The reverse coupling has also been found to occur after deformation of the fiber.In still another embodiment of this invention we have found that light from the leaky core modes can couple to the bound core modes and more easily to higher order bound core modes when the fiber is deform- ed. Thus if the bound core modes are kept dark (modes B) and the leaky core modes are excited (modes A) the strain of deformation of the fiber can be measured by monitoring the light coupled to the bound core modes. A preferred embodiment of this is when the high order bound core modes and leaky core modes are the A modes. This can be utilized as follows. Assume that light is injected into the fiber in all core modes. After some long distance and before the deformer, the fiber is necked down by heating and stretching a small sec- tion. This would allow light to propagate in all core modes except the highest ones which are now kept dark. At the deformer, light from the lower order bound core and leaky core modes would couple to the higher order core modes. These high order core modes could then be separated out be spatial filtering of the light coming from the end of the fiber and then detecting this light.A fiber can have a multistructure configuration with more than one clad. Since such a fiber suffers less attenuation due to microbending, it is desirable to use a multicladding fiber when such losses are of major consideration. Also a fiber can have more than one core surrounded by the same clad. In this case, modes A can be in one core, while modes B can be in another core.A deformation of a fiber applied by a deformer will cause a redistribution of light among various modes. In particular, some of the light in the core modes propagating in the forward direction will be coupled to the light in the .core modes propagating with backward direction, i.e., from the deformation back to the light source. This light can be detected by putting a beam splitter, e.g., a half-silvered mirror at 45° with respect to the fiber axis, between the light source and the front end of the fiber. Even though the sensitivity of .such a sensor is expected to be reduced, such a system is preferable under conditions of large fiber deformations, because it is simpler and less expensive since only one fiber is used.Most types of optical waveguides can be used in this invention. For example, the optical waveguides can be planar with two or more dielectric layers. In this case, integrated optics techniques could be used for manufacturing such a waveguide. Light can be injected into certain modes A, e.g., the first 2 guided modes. The remaining guided modes B, are kept dark. Any deformation of the waveguide could couple light from bound core modes A to modes B, i.e., from the first two bound core modes to, for example, the third bound core mode. Note this example shows that one need not couple between two different types of modes but one can couple between lower and higher order modes of a single type. The power of the light in modes B, i.e., the third mode, is finally detected by an optical detector. If a compact sensor is desir¬ ed, then the source, the waveguide, and the detector can be fabricated on a single substrate.Detector SystemThe purpose of the detector system is to monitor the changes in the power in the B modes. The actual form of the detector system will depend on the type of B modes to be monitored, the sensitivity required and the use of the sensor. The detector system consists of a means to isolate the B modes, a means for trans¬ mitting them to an optical detector and the optical detector.The means for isolating the B modes depend on the type of B modes to be detected and the distance by which the detector system and the sensing system are to be separated. In the simplest embodiments the detector system is located within 10 meters of the sensing system but preferably as close as is practical to the sensing system. In these embodiments if the B mode or modes are specific bound core modes, they can be isolated by observing the far field intensity directly with a detector. For example if the waveguide is capable of supporting 11 modes and the 10th and 11th modes are the B modes the optical power in these modes is separated from that of the other modes in the far field radiation pattern. As illustrated schematically in Fig. 20 the power in these two modes indicated by the rays 107 and 109 may be monitored by placing optical detectors 115 and 117 in the areas in the ob¬ servation plane 111 which contain power from the B modes. If in any embodiment the B modes are leaky modes they may be observed by monitoring the near field power distribution of the radiation from the end of the fiber. It is preferred that for this embodiment that a step index fiber be used. In this case the power in the leaky modes appears superimposed on a constant background of power from the bound core modes and thus the contribution from each type of mode is easily sep¬ arated in the near field pattern. If in any embodi¬ ments the B mode or modes are clad modes they may be detected by observing the near or far field power distribution. In the near field the light in the clad modes such as 91 and 93 forms a ring around the light from the core modes such as 87 and 89 and is thus detected as illustrated in Fig. 19 by a suitable geometric arrangement of optical detectors 101 within the ring formed by the light from the clad modes. A similar arrangement was used for detection of the clad modes in example 1. A ring-shaped detector could be used for the detection or the center of the light distribution can be blocked and then the ring can be focussed down onto the surface of an optical detector. In another embodiment where. the B modes are clad modes, the detector as illustrated in Fig. 21 may consist of an integrating cell 119 filled with a medium having index equal to or greater than that of the waveguide clad. In this case the clad modes are stripped by the index matching medium and are detected within the integrating cell. ; If the B modes are to be detected at a large dist¬ ance from the sensing system it is preferable to couple the B modes to the bound core modes of another fiber waveguide, called the detection waveguide, for sub¬ sequent detection by the detector. The detector could be (a) more than 10 meters from the hostile location of the deformer, e.g., at high temperature and/or pressure; (b) more than 500 meters from the location of the deformer in the case where central location for col¬ lection of information is desireable, e.g., acoustic detection for security purposes in a bank; (c) further than one kilometer from the inaccessible location of the deformer, e.g., deep in the ocean.As in the case of a remote source, choices of the detector waveguide for remote detection would be similar to those for the transmitting waveguide. Depending on the type of B modes, various methods of coupling to the bound core modes of the detector waveguide are preferred They may be coupled out of the core of the sensing wave¬ guide into the core of the detector waveguide by cou¬ pling the fields of the leaky modes to the core of the detector waveguide. In one embodiment the waveguide could have a section with two parallel cores. The first core would contain the B modes which can couple through their evanescent fields to the bound core modes of the second core. In a second embodiment a prism coupler could be used to couple power from the leaky modes of ■ the sensor waveguide to the bound core modes of the detector waveguide.If the B modes are clad modes, they may be coupled to the bound core modes of the detector waveguide.' This can be done for example by fusing or glming a small sec¬ tion of the clad of the sensor fiber to the core of the return fiber as is illustrated in Fig. 22 where 121 is the core and 123 the clad of the return fiber and 125 is a core mode of the return fiber. In another embodiment the clad modes could continue to propagate in the clad if an outer clad of lower index than the inner clad is provided for the return fiber. As an example the outer clad could be a low index plastic. If the B modes are high order bound core modes they may be transmitted to t detector through the detector waveguide with no changes. ' OMPI There are many types of detectors that can be used. If cost is of major consideration, an inexpensive silicon diode is preferred as a detector. Moreover, a silicon diode has optimum detectivity in the range of wavelengths of 0.8 to 0.9 um where an optical fiber could have very small loss. Such a diode is a silicon PIN diode which has linear responsivity over a wide range of optical power. Thus, when a detector with linear responsivity is desired, a silicon PIN diode is preferred. On the other hand, a silicon avalanche diode can detect lower light power than a PIN diode. Therefore, when very low light power is to be detected, a silicon avalanche diode is preferred. Another detector very sensitive in the region of wavelengths less than 0.7 μm is a photo-multiplier. Such a detector is preferred when maximum sensitivity is desired.Dual Nature of SensorThe invented sensor can be used for measuring force, as well as displacement; when the force is in the form of weight on the deformer as in Example 1 the sensor can be used to measure weight. When the deformer is exposed to a pressure a total deforming force equal to the pressure times area of deformer is transmitted to the fiber. To understand this dual nature of the sensor a simple example is considered. A section of an optical fiber is supported by two ridges, while a force is applied to the fiber by a third top ridge, which interleaves the bottom two ridges. It can be shown that the displacement, y, of the fiber is given in terms of the force F applied to the upper tooth by the following equation:Y = where L is the distance between the two supporting ridges, E, is Young's Modulus of Elasticity of the optical fiber material, and d is the fiber diameter.Using a typical set of numbers, e.g. L = 0.3 cm, F = 10 —3 dynes, E = 7.3 x 1011 dynes/cm2, and d = 0.01 cm (= 100 μm) , the value of the displacement is found to be:—8 y = 0.2 x 10 cm = 0.2 A.-3 That is, a force of 10 dynes would result in a dis- placement of 0.2 A.In order to estimate the highest frequency range over which the sensor is effective, one should calculate the resonant frequency of the waveguide. It can be shown that the fundamental resonant frequency f.. of the system above is given byE_ fl = 81/ P where p is the density of the fiber material. Using the same numerical values listed above with p = 2.23 gm/cm it is found that f1 - 25 KHzThis value for the fundamental resonant frequency can be increased by decreasing L.In considering the response of the sensing element, one should consider the mass of the deformer, other resonances of the system, etc. However, the fundament¬ al limitation comes from the waveguide, as it was dis¬ cussed above. For frequencies low compared to the fundamental resonant frequency, f, the response of the sensor is a weak function of the frequency. For higher frequencies the response of the sensor would exhibit peaks at the resonant frequencies of the waveguide. Multiple SensorsPressure sensors discussed above may be arranged in a spatial array to provide information such as bearing of a sound source. A line configuration of sensors along a long cable can be used for passive sound detection. The number and spacing of sensors will determine the directivity of. the array. At some distance from the source of light, a set of pres¬ sure optic sensors are arranged in a series connected by an optical fiber waveguide with spacing between sensors depending among other things on the wavelength of the sound to be detected. An essential feature of this system is that the light injected in A modes suffers little attenuation as it propagates along the fiber and past the sensors. At each sensor, where the waveguide deformation takes place, only a small fraction of the light is coupled to mode B, the dark mode. Such an array may be fixed in place with the signals monitored from a fixed station in which case the transmitting and detector cables need only be long enough to reach from the monitoring station to the area in which the. sensors are arrayed or they may be towed from a moving station such as a ship. In the case of a towed array it may be necessary that the sensor array be separated by some distance from the towing station to avoid the detection of noise from the towing station. In this case it is preferred that the sensor array be a distance of the order of 1 km from the towing station. An optical fiber is a relatively inexpensive opti¬ cal waveguide. Therefore, the use of an optical fiber is preferred when cost is of major consideration. Moreover, an optical fiber is available in various lengths, up to some kilometers. After each deformer jUREAOMPI the light in modes B can couple into another fiber which is connected to a detector. This is illustrated schematically in Fig. 23 where 133, 13-5 and 137 are fibers returning signals from sensing systems 127, 129 and 131 to their respective detectors. This is pre¬ ferred since it allows the use of more than one deformer on a single long length of optical fiber waveguide. Moreover, when a pulsed laser is used as the light source, the optical fibers carrying light from modes B are preferred to couple to one common return fiber since this reduces the cost of the pres¬ sure sensor. This is illustrated schematically in Fig. 24 where 133, 135 and 137 are fibers connecting the sensing systems 127, 129 and 131 to the return fiber 139. In the case of a common return fiber the light from different sensors can be separated by the time delay introduced because of spatial separation between the sensors. In fact this common return optical fiber when preferred can be the main fiber. Such an embodiment is shown in Fig. 25 where the fiber section 139 is joined to the main fiber 141. In this case, in the main fiber there would be light propagat¬ ing in both directions.In some cases various parameters of a system should be monitored as a function of time, e.g., in a drilling well it is desirable to know temperature, pressure, etc., at the same time. In such a case it is preferred to use different deformers for different uses. In one embodiment the sensor array would consist of temperature and pressure sensors spaced as desired along the waveguide. In other cases one parameter of a system should be monitored as a function of another parameter, e.g., with a sensor in the form ofEATOMPI a long array in the ocean, temperature can be monitored as a function of depth. This can provide various information, e.g., about ocean currents useful for fishing, etc. As a further illustration of multiple sensors, consider a simple array with many deformers along a straight fiber. They are spaced for determining the direction of a source producing sound waves, e.g., a ship in the ocean. Let us now suppose that the light in B modes is coupled to a common return fiber as in Fig. 24. Additionally we suppose that the sensing regions are separated by .375 meters (which is 1/4 wavelength of sound in water at 1 K Hz) . The differ¬ ence in arrival times of the light coming from two neighboring deformers is t = 3.7 nsec. (Note this includes the fact that light arrives later in the sensing region .375 meters further away from the source.) In order to resolve such a time difference, a GaAs laser should preferably be used as the light source. On the other hand, a Nd:YAG laser can be used when the deformers are considerably further apart, since usually it emits pulses 90 nsec or more wide, but has more power. Moreover, due to pulse dispersion the light pulses become broader as they propagate through the fiber. Thus, in the present embodiment if the deformers are at a distance of, say, 300 meters or more from the light source, a step fiber cannot be used because the light pulses would overlap, and therefore, they could not be resolved. In this case a graded index fiber of a single mode fiber should be used since these will in general have the necessary band width to propagate a 1 nsec pulse.*BUREATT„_OMPI ExamplesIn all the following examples the optical wave¬ guide was a step profile, multimode optical fiber consisting of a core and a clad without any coating. The fiber was made by the molecular stuffing process (U.S. Pat. No. 3,938,974). It had a 96% silica clad and a core doped with cesium oxide. The numerical aperture of the fiber was 0.22. The core diameter was ~75 μm and the core plus clad diameter was -105 μm. The attenuation of the fiber was found to be ~22 dB/km at 0.9 μm wavelength and full numerical aperture.As a figure of merit for comparing different em¬ bodiments of this invention it is useful to define a quantity we label the force mode coupling sensitivity K. This is defined as. P_ - P K = -* 2PAF where Pβ is the total optical or infrared power in the normally dark modes B including that due to deformation of the optical waveguide; F is the force on the deform¬ er, P is the background optical power in modes B and P_ is the optical power in modes A. In the examples below PB_ = Pcl, the p^ower in the clad, and PA_ =* Pco. the power in the core.Static Pressure Example 1In the example the light source was a xenon lamp emitting incoherent light in the visible and infrared wavelength region (.4NM) which was chopped and focused by a 2Ox microscope objective on the end of the fiber forming a cone. The axis of this cone was in line with the fiber axis. A 5 cm section of a 2 meter long fiber was subject to pressure applied by a deformer. TheBU EΛOMPIAl/ - WΪPO deformer consisted of matched steel pieces having corrugated or sawtoothlike surfaces with interleaving ridges having a period of 1 mm and with edge sharpness of 25 μm. A magnified image of the fiber output face is formed at the image plane of a 2Ox microscope objective and a projection lens. A silicon PIN diode detector was arranged to scan the image field trans¬ versely. The output of the detector was fed into a lock-in amplifier and then to a computer for analysis. Such a detection system permitted us to study separate¬ ly the light in B modes or clad modes, with power Pβ, and the light in modes A, core modes with power P .The top piece of the deformer weighed 45 grams. On top of this piece weights were added. Thus, P /P was studied as a function of applied weight. In the limit of small weights we found:PB - PQ = (1.6 + .3) x IO 4 PA/gm (1) where P is the power of the background light which will be discussed later. Thus for this embodiment of the invention the force mode coupling sensitivity-4 K = (1.6 + .3) x 10 /gm. For weights greater than45 gm the sensitivity decreased, indicating non-linear behavior.Propagation of light in the clad modes is depicted in Figure 4. As it can be seen, clad modes propagate both in the core and in the clad. The ratio of the intensities between the reflected and refracted beam at each interface is a complicated function of the incident angle, the change in index of refraction and the polarization of the ray. However, a substantial part of thepower of the clad modes propagates in the core. Thus, when we detect the light in the B modes, which in this case are clad modes, using near field imaging of the fiber end, we substantially underesti¬ mate the sensitivity of the sensor. If a coupler was built that could extract substantially all the power in clad modes, the sensitivity could possibly be increased by a factor of two or more.Example 2In this example the periodicity of the inter¬ leaving ridges of the two corrugated pieces of the deformer was 0.3 mm while all the other components and dimensions were the same as in Example 1. The force mode coupling sensitivity, K, of the sensor was found to be (1.4 +_ .4) x 10 -4/gm, similar to that found for Example 1, Eq. (1) , for weights up to~50 gm, while for bigger weights it was found to be smaller.Example 3In this example, the shape of the two pieces of the deformer were different from the case of Example 1, while all other components were the same as in Example 1. Two different experiments were done in thisExample. In the first experiment, the top piece of the deformer was flat while the base piece was corrugated with a ridge period of 1 mm. The force * mode coupling sensitivity of the sensor in this case was found to be (2.0 + .4) x 10 /gm. This is approx¬ imately 8 times less than the sensitivity of the sensor in Example 1. However, the response of the present sensor was found to be a linear function of weight up to or more than 450 gm. Thus, even though such a sensor has smaller sensitivity than the sensor in Example 1, it could be useful when linear responsivity over a larger dynamic range is desired. In the second experiment, the deformer consisted of two flat pieces. In this case the force mode coupling sensitivity was found to be appreciably lower than the sensitivity of the sensor using one flat and one corrugated surface.Example 4In this example every component was the same as in Example 1. The only difference was the way that the light from the light source was focused on the end of the fiber in such a way that the axis of the cone of light was at an angle with respect to the axis of the fiber. When the angle of the.-light cone is very small, the light is injected into the first or lower order bound core modes. As the angle of the light cone increases, the light intensity in the higher order bound core modes plus leaky core modes will be increased. This is the present case: the optical axis of the light injected into the fiber was 10° with respect to the fiber axis. In this case the sensitivity of the sensor was found to be about 50% higher than in Example 1. Thus a deformation of the fiber appears to result in stronger coupling of light from the leaky core modes to clad modes than from the bound core modes.The main conclusion of this example is that the force mode coupling sensitivity of the sensor can be enhanced by injecting the light in A modes where A modes are high order bound core modes, or even better, leaky core modes.Example 5This example is similar to Example 1, with respect-B _ϋ0RMtP1<_ur to how the light couples from modes A to modes B. However, the light source and the detector used here are different from the case of Example 1. This example allows a measure of the dependence of the results found in Example 1 upon the type of light sources and detectors used. In this experiment, the light source was an Argon-ion laser emitting 1 watt coherent light at .5145 μm wavelength. The coherent light was passed through a coherence scrambler con- sisting of a rotating transparent plastic disc which makes the light incoherent. The incoherent light was then focused by a 20x microscope objective on the end of the fiber. A 5 cm section of a 10 meter long fiber was subject to deformation due to the deformer. The deformer was identical to the deformer of Example 1. Weights were added to the top piece during the experiment. A magnified image of the fiber output face was formed by a 20x microscope objective and a projection lens in a plane of a pinhole with an 0.5 mm diameter. As in Example 1, the light in modes A and B could be detected separately. The light transmitted through the pinhole is then focused at the photo-cathode of the photomultiplier. The output of the photomultiplier was preamplified, amplified, discriminated, and then counted by a linear ratemeter, whose output was recorded. The force mode coupling sensitivity of this Example was found to be (2.0 + 0.4) x 10 -4/gm, within experimental error the same as the results of Example 1. This indicates the results are independent of the types of light sources and detectors used. In particular, since the light source used in Example 1 was a Xenon lamp emitting light in a wide wavelength region, fromOMPIWIPO 0.4 to 1.1 μm, while the light source in this Example was an Argon-ion laser emitting light at 0.5145 μm, the fact that the results were found to be similar shows that the invented sensor is not strongly wave- length dependent.The above experiment was repeated with the periods of the interleaving ridges of the two corrugated pieces of the deformer of 0.3 mm and 3 mm. The results were found to be similar to the case of the 1 mm period for small weights (up to 50 gm) . The force mode coupling sensitivity was found to be (1.4 + 0.7) x 10 -4/gm for a period of 0.3 mm and (1.6 HH 0.3 )~ x 10-4/gm for a period of 3 mm. For heavier weights the sensitivity of the sensor with 0.3 mm period was found to be smaller than with 1 mm period in agreement with Example 2.Example 6In this Example coherent light was used, which is in contrast to all other examples where the light was incoherent. From the comparison of the results of this example to the other examples, we can see how the responsivity of the invented sensor changes when an incoherent light from a lamp or a light emitting diode is used versus the coherent light from a laser. In this experiment the light source was an Argon- ion laser emitting coherent light at 0.5145 μm wave¬ length. The light was focused by a 2Ox microscope objective on the end of the fiber. A 5 cm section of the fiber was subjected to deformation due to the deformer. The deformer of Example 1 was used. After the deformer at a short distance, ~20 cm, the fiber passed through two pinholes located on two opposite3 surfaces of a 1 cm cube. The inside surfaces of the-BΪ3REΛLT-OMPI - < > -W1PO-. ^ cube were covered by 6 photocells whose output was measured by a digital millivoltmeter. The cube was full o glycerine which, having a refractive index higher than that of the fiber clad, coupled out the light from the clad modes, which then was detected. The light in the clad modes, modes B, were the result of coupling from the core modes, modes A, by the deformation. The total power of the light in the core modes was found by bringing the end of the fiber inside the cubic detector. Thus, the ratio of the light power in the clad modes to the core modes was determined as a function of the applied weight on the deformer. The force mode coupling sensitivity was found to be 1.2 x 10 -4/g . This sensitivity is lower than the one given by Eq. (1) , Example 1. This discrepancy should be attributed to an experimental difficulty of detecting all the clad light after the sensing element. The reason for this is that the section of the fiber between the sensing element and the cubic detector was bent. This bending caused some light in.the clad modes to radiate away from the fiber before it was detected.From the results of this example in relation to other examples, we conclude that there was no signi- ficant difference in the responsivity of the sensor when coherent or incoherent light was used.Summary of Examples 1-6From the comparison of the above static pressure examples we can conclude the following when multimode fibers with a step index profile are used.(a) The force mode coupling sensitivity of the invented sensor is substantially independent of the optical source. A xenon lamp or laser gave about the same results. This shows that the sensor does not depend strongly, if at all, on the wavelength of light and on the coherent or incoherent nature of lgiht. In selecting the optical source, the important considerations would be: its cost, its light power, and collimation of the light beam.(b) The force mode coupling sensitivity of the sensor is also independent of the detector. An inexpensive silicon diode, a cubic photocell, or .a more sensitive photomultiplier have the same results. On selecting the detector, the important considerations would be: its cost, its response time, light sensi¬ tivity for the particular optical source used, and how conveniently and easily the detector can be adapted to the geometry.(c) The shape of the deformer plays an important role in determining the force mode coupling sensitiv¬ ity of the sensor. We found that an improved coupling was achieved when the deformer was a set of two cor- rugated plates with interleaving ridges. When one of these plates was flat the sensitivity decreased by almost one order of magnitude. This shows that for a given applied force, bending the fiber introduces more light coupling than squeezing the fiber. The optimum period of the ridges seems to be of the order of 1 mm, even though it was found that the mode coupling of the sensor was not a strong function of the period, for periods from 0.3 mm to 3 mm.Displacement Example 7The previously described experiments were made to measure static pressure in the form of applied weights on the fiber. The purpose of this example is to find the responsivity of the invented sensor when one of the two pieces of the deformer is displaced relative to the other.In this experiment thelight source used was an Argon-ion laser emitting light at 0.5145 μm wavelength. The coherent light became incoherent by passing through a scrambler, i.e., a rotating transparent plastic wheel. Then the light was focused by a 2Ox microscope objective on the end of the fiber. A 5 cm section of the fiber was subject to deformation due to the deformer. The deformer was a set of two plastic pieces of a corrugated form with interleaving ridges with period of 3 mm. The top piece was attached to a micrometer which could move vertically. The bottom piece was rigidly mounted on a fixed base. Thus, by moving the top piece, the fiber could be deformed by a known amount. A magnified image of the fiber output face was formed by a 20x microscope objective and a projection lens in a plane of a 0.5 mm diameter pinhole. The light transmitted through the pinhole was then focused at the photocathode of a photomulti¬ plier, whose output was amplified, counted and then recorded. It was found that for a thousandth of an inch displacement of the top piece with respect to the lower piece of the deformer:or where P is the power of the background light and K1 is the displacement mode coupling sensitivity.Dynamic Pressure Example 8In the above examples, the pressure or displace¬ ment applied to the sensor was static in time. In this example, the pressure applied to the deformer changed periodically in time with some frequency.This resulted in a periodic deformation of the optical fiber, which in turn caused periodic coupling of the light from A modes to B modes. In this experiment, light from an Argon-ion laser was made incoherent before injection into the fiber, in a way similar to ■Example 7.. A 5 cm section of the fiber was subject to deformation due to the deformer. The deformer was a set of two plastic pieces with corrugated ridges with interleaving ridges having a period of 3 mm. The top piece was attached to the end of a micro¬ meter which could move vertically. The bottom piece was glued to the center of a stretched drum head. Beneath the drum a speaker was placed in an enclosure. Th -speaker was driven from a sinusoid signal gener- ator at 70 Hz. When the speaker vibrated, the air coupled the vibrations to the drum which in turn vibrated the bottom piece of the deformer, thereby deforming the fiber.As in the previous example. Example 7, a magnified image of the fiber output face was formed in the plane of the pinhole. The light transmitted through the pinhole is then detected by the photomultiplier. In this experiment, the output of the photomultiplier was amplified and applied to a low pass filter which eliminated all signals at frequencies higher than 1 KHz. The analog output signal and the signal from the signal generator were viewed on a double trace oscilloscope. The detected signal was found to be sinusoidal with the same frequency as the driver-BϋR A TOMPI RNATIO ' generator.Example 9The purpose of this experiment was twofold: first, to check the efficiency of stripping the clad modes before the sensing element and, second, to compare the near field detection system, which was utilized in Example 7 and shown schematically in Fig. 19, with the total scattering detection system utilized in. Example 6 and shown schematically in Fig. 21. The source system was the same as the one used in Example 7. The deformer was a 5 cm. long set of two vertically placed corrigated plates with interleaving ridges with period 1 mm. A 90 cm fiber section before the deformer section of the 3 meter long fiber was stripped by a black paint. This stripping was found to reduce the initial background light power by as much as 50 times.The light power in modes B before deformation was less than 0.1% of the light power in modes A. The fiber passed vertically through the deformer without any bending of the fiber before or after the deformer and then through the cubic detector which was partly filled with glycerine. The result of this experiment was that the sensitivity K1 measured, K1 = 1.2 x lθ 4/μm. was approximately equal to that of Example 7.Calculations of Minimum Detectable Signal PowerThe following theoretical calculations are present¬ ed here for the purpose of emphasizing the sensitivity of the invention which is such that its limits could not be accurately measured by the instrumentation employed in the examples, but could be measured by more sensitive commercially available means. We offer these calculations for illustrative purposes and do not wish to be bound by the veracity of this theoretical approach.From the results of the above examples and from the knowledge of the characteristics of the commer¬ cially available components, the minimum detectable signal of our sensor can be calculated. The minimum detectable signal power is defined as the signal power which is equal to the total noise power. To calculate this sensitivity, the signal, i.e., the power of the light in modes B, should be compared with the various noises present. The minimum detectable power is then related to the minimum detectable pressure, force, or other parameter being measured.The main steps of these calculations are: (a) expression of the signal power as a function of the light power in modes A. (b) estimation of the noise due to the background light in B modes in the sensing element.(c) estimation of the minimum detectable light power by the detectors.A. Signal Power in the B Modes The signal light power P-τ^ in the B modes is given by the following expressionPSIG β PB Po * KPAF (1) where P. 13. is the power in the clad modes, PO is the background power in modes B, K is the force coupling coefficient, P, is the power in the bound core modes and F is the applied force.For the configuration of Example 1, Eq. (1) the fU E^OMPI o -7 value of K is found to be 1.6 x 10 /dyne,B. Noise in the B ModesAny fluctuation in the background light, P , present in the clad of the sensor element is noise. This is minimized by stripping the light in the clad which comes from sources outside the sensing region. This stripping is done just before the sens¬ ing element. The main noise power in the clad is main¬ ly caused by Rayleigh scattering, S, out of the core in the region L of the sensing element. This noise power, which is the fluctuation in S, we denote as N . Eor a fused silica core we have found that theRayleigh scattering loss S = 1 dB/km for wavelength—6 of .9 μm. Thus, S - 2 x 10 /cm. However, we have found that the angular distribution of the Rayleigh scattering is proportional to 1 + cos θ, where θ is the angle of observation from the forward direction. Thus, we see that only a fraction, denoted by f, of the-light power Rayleigh scattered from the bound core modes will become light propagating forward as clad modes. It can be shown that when the surrounding medium is air f - 0.2. By utilizing other surrounding media f can be reduced at least one order of magnitude. The noise power N_ associated with the D. C. background of power P is determined from the relation¬ shipN iBs. = {P O t/ (hv) } 1 / 2 x hv/t ( 2) where the radical is a measure of the number of photons and hv/t is power per photon, where h is Planck's constant, t is the time interval, and v is the frequency of the light. P is given by the following equation: Po = PASfL • (3) where L is the length of the sensing region.The light signal is detected by an electronic device which has its own noise characteristics, thus from Eqs. 1, 2 and 3 we have the signal-to-noise ratio:signal KPA.F(4)Total Noise (PASLfhv/t) x 2 + N,If N, . is taken to be the noise-equivalent power for a silicon PIN detector we have i •,u*, „N 10 11* watts d,et. = ■ sFor a 1 cps bandwidth, we haveNdet = IO 1 watts (5)In order to calculate N we specify the various para¬ meters shown in Eq. 2 and 3. For L = 5 cm, t = 1 sec,15 v = c/λ where c - 3 x 10 cm/sec is the velocity of light in vacuum and λ - .9 μm is the light wavelength used in these experiments and S « 2 x 10 /cm. If the fiber is surrounded by air, then we get f = .2. If PA = 10 milliwatts which is a typical light power20 for an inexpensive light emittingdiode or a GaAs laser, we haveNR = 6.64 x IO-1 watts (6)Recognizing that NR is proportional to the square root of P then the light power P could be reduced to25 0.25 mwatts before detector limitation would begin to dominate (i.e., N_. > N ) .The minimum detectable force Fmm. can be determined by equating signal power, P . - , to total noise power in Eq. (4) , and using K given in Example (1) . We find F . = 5 x 10-5 dyne. If the area where this force mm J 2 is applied is 10 cm then the corresponding pressure—6 ~ . is 5 x 10 bars, mFor higher light power P A,.. Fmm. and ~mm. decrease, Thus, if Pj. = 1 watt, which corresponds to the case of a gas or a Nd:YAG laser, we find F —6 mm. = 5 x 10 dyne.This would correspond, if the device were to be used as a weighing scale, to 5 x 10 -9 gm. Assuming an area2 of 10 cm ,_7 ~mm. = 5 x 10 μbars.In general, since N, . is not a limiting factor for light powers higher than a milliwatt, from Eq. (4) and the λ -4 dependence of Rayleigh scattering we haveFmin β l/K[(SfhcLλJ)/(.tPAλ5)]l/2 (7) From this equation we see that in order to increase the sensitivity of the invented sensor, i.e., to lower Fmm. , we can:(a) decrease f by minimizing the difference between the refractive indices of the medium surround- ing - the fiber, nm, and the clad,' ncl, ,(b) increase PΆ, the light power injected in the fiber core,(c) increase K, the coupling sensitivity. This last one can be done by proper design of the deformer, or by proper light injection of the light in the fiber, i.e., by having modes A to be high order guided modes or leaky modes.C. DisplacementWorking in a similar way as before, we can rewrite Eq. (1) as Psi.gnal. = PB_ - Po = KlPA_D ; where K1 = 10~4/'μ^m and D: is the relative displacement of the deformer. This equation is similar to Eq. (1) if we substitute F forD and K for K1. Then if we substitute F . for D . mm mm in Eq. (7) and K for K1, we have where Dmm. is the minimum detectable displacement,If we use the same values for the various parameters in Eq. (8) for the static pressure case, we can find that with 10 mwatt of core power we can measure dis- placements of less than 1 A (i.e., 10 —8 cm). | Claims1. A sensor comprising an optical waveguide having at least two groups of modes denoted as A and B, each group containing at least one mode, an optical light source injecting light into said waveguide, deformer means for applying stress to a region of the waveguide resulting in a deformation of said region of said waveguide to produce a change in the coupling of light between A modes and B modes, 0 a^d an optical detector to detect said change in the coupling of light.2. A sensor as in claim 1 further comprising means to cauHe light entering said region to be in both A and B modes, and said optical detector having 5 means to detect the light in B modes only.3. A sensor according to claim 1 further comprising optical means to cause light entering said region to be substantially in A modes, and said optical detector having means to detect the light in B20 modes only.4. A sensor according to claim 3 wherein said A modes are lower order bound core modes and said B modes are higher order bound core modes.5. A sensor according to claim 3 wherein said A modes 25 are bound core modes and said B modes are leaky core modes.6. A sensor according to claim 3 wherein said A modes are bound core modes and said B modes are clad modes.307. A sensor according to claim 6 wherein said bound core modes are high order bound core modes. 8. A sensor according to claim 3 wherein said A modes are bound and leaky core modes and said B modes are clad modes. 9. A sensor according to claim 3 wherein said A modes are leaky core modes and said B modes are bound core modes. 10. A sensor according to claim 3 wherein said A modes are leaky core modes and said B modes are clad modes.11. A sensor according to claim 3 wherein said A modes are clad modes and said B modes are bound core modes.12.. A sensor according to claim 3 wherein said A modes are clad modes and said B modes are leaky core modes.13. A sensor according to claim 3 wherein said A modes are clad modes and said B modes are leaky and bound core modes..14. A sensor according to claim 3 further comprising means to remove light from said B modes before entering said region so that the amount of light in said B modes in said region is less than 1% of that in said A modes.15. A sensor according to claim 1 wherein said deformer means comprise at least two objects in contact with the waveguide. 16. A sensor according to claim 15 wherein at least one of said objects has a rough surface in contact with the waveguide.17. A sensor according to claim 15 wherein at least one of said objects has at least one ridge on its surface in contact with the waveguide.18. A sensor according to claim 17 in which each of said objects has a set of ridges and said sets interleave each other.19. A sensor according to claim 1 wherein said gURcaTTOMPI deformer means is a deformable object attached to at least two points of the waveguide.20. A sensor according to claim 15 further comprising a pressure sensitive enclosure connected to said deformer means so that a change in pressure at the enclosure causes a change in deformation of said region of said waveguide whereby said sensor measures.' pressure.21. A sensor according to claim 20 further comprising a low frequency pressure transmitting device extending through the wall of the enclosure which allows the pressure inside the enclosure to be essentially equilibrated with low frequency com¬ ponents of the pressure external to the enclosure so that the change in deformation of the wave¬ guide is determined only by high frequency components of said external pressure, whereby said sensor measures the high frequency component of the external pressure. 22. A sensor according to claim 21 wherein said low frequency components are less than 1 Hertz, and said high frequency components are greater than 20 Hertz.23. A pressure sensor according to claim 20 wherein said sensor is a hydrophone.24. A sensor according to claim 15 in further com¬ prising means connected to said object such that deformation of said region is proportional to acceleration. 25. A sensor according to claim 1 wherein the deformer means comprises at least two materials having dissimilar thermal expansion coefficients and configured to cause a change in deformation of said region of said waveguide upon change in temperature, whereby said sensor is used to measure temperature.26. A sensor according to claim 1 in which the optical waveguide is predeformed.27. A sensor according to claim 1 which further comprises means to cause said light source to be amplitude modulated.28. A sensor according to claim 1 wherein said optical light source is a semi-conductor laser.29. A sensor according to claim 3 wherein said A modes in said region are bound core modes, and wherein said optical means maintains the numerical aperture of the light entering said region below the numerical aperture of said region.30. A sensor according to claim 3 wherein said A modes in said region are low order bound core modes, and wherein said optical means maintains the numerical aperture of the light entering said region sub- stantially below the numerical aperture of said region.31. A sensor according to claim 3 wherein said wave¬ guide is an optical fiber waveguide, said A modes in said region are bound and leaky core modes, and said optical means includes a reduced diameter portion of said optical fiber waveguide between said light source and said region.32. A sensor according to claim 3 wherein said A modes in said region are bound and leaky core modes, said waveguide is an optical fiber waveguide, and said optical means include means causing the numerical aperture of the light to be greater than the numerical aperture of said optical fiber waveguide, and means for removal of clad modes.33. A sensor according to claim 14 wherein the means to remove enough light from said B modes comprises a medium surrounding the waveguide, said medium5 having an index of refraction greater than or equal to the index of the outer surface of said waveguide.34. A sensor according to claim 1 wherein said light source is separated from said region by an optical10 fiber waveguide.at least 10 meters in length.35. A sensor according to claim 1 wherein said optical detector is separated from said region by an optical fiber waveguide at least 10 meters in length.15 36. A sensor according to claim 1 wherein said optical detector is a silicon diode optical detector.37. A sensor according to claim 3 wherein said means to detect the light in said B modes allow light to radiate from the end of the waveguide, said20 optical detector being positioned in such a fashion as to detect only certain angular com¬ ponents of the light from the end of the waveguide.38. A sensor according to claim 3 wherein said means to detect the light in said B modes comprise25 optical means for imaging in a plane the light from the end of said waveguide, and means to detect light only in certain regions of the image on said plane.39. A sensor according to claim 3 wherein said B30 modes are clad modes, and said optical detector comprises a medium surrounding said waveguide and having an index of refraction equal to or greater than that of the outer surface of saidOMPI_ waveguide providing means to detect light leaving said clad.40. A sensor according to claim 1 further comprising a section of an optical fiber waveguide for transmitting light from said B modes connected to and extending between said waveguide and said optical detector.41. A sensor according to claim 1 comprising one said optical light source, more than one said region, 0 more than one said deformer means, and more than one said optical detector.42. A sensor according to claim 1 comprising one said optical light source, more than one said region, more than one said deformer means, and one said 5 optical detector.43. A sensor according to claim 42 wherein said wave¬ guide comprises an optical fiber waveguide extend¬ ing from said light source and including each of said light regions.20 44. A sensor according to claim 41 wherein at least one said region and the respective deformer means is sensitive to pressure, and at least one said region and the respective deformer means is sen¬ sitive to temperature.25 45. A method comprising injecting light into an optical waveguide having at least two groups of modes A and B each group containing at least one mode, applying stress to a region of the waveguide causing a deformation of said region to produce30 a change in the coupling of light between A modes and B modes, and detecting said change in the coupling of light. 46. A method as in claim 45 comprising injecting light into said waveguide in both A and B modes and detecting the light in B modes only. 47. A method as in claim 45 comprising injecting light into said waveguide substantially in A modes, and detecting the light in B modes only. 48. A method as in claim 47 further comprising remov¬ ing light from said B modes before entering said region so that the amount of light in said B modes in said region is less than 1% of that in said A modes. 49. A method as in claim 45 wherein stress is applied by compressing the waveguide between two objects at least one of which has a rough surface.50. A method as in claim 45 further comprising enclos¬ ing said region of the waveguide with a pressure sensitive enclosure which allows the external pressure to cause the deformation of said region whereby pressure is measured.51. A method as in claim 50 further comprising equili¬ brating the low frequency components of the external and internal pressure whereby only the high frequency components of the external pressure are measured.52. A method as in claim 50 where the pressure is measured in water. 53. A method according to claim 45 wherein stress is applied to more than one said region of said wave¬ guide for the purpose of making a plurality of measurements.IJO EATTOMPI^SNATlO | LITOVITZ T; MACEDO PEDRO; MACEDO P | LAGAKOS N; LITOVITZ T; MACEDO P; MEISTER R; MOHR R |
WO-1979000379-A1 | 1,979,000,379 | WO | A1 | XX | 19,790,628 | 1,979 | 20,090,507 | new | B23P1 | null | B23H1 | B23H 1/02C | IMPROVEMENTS IN METHODS AND APPARATUS FOR ELECTRICAL DISCHARGE MACHINING | A method and apparatus for use in EDM are described. Known EDM techniques require the voltage applied between the electrode (11) and the workpiece (10) to be removed either periodically or after a predetermined integrated current has passed and the resulting interruptions add to the time required for machining. In the present invention the voltage is applied until an arc is imminent or is detected and then the voltage is removed for a time sufficient to allow de-ionization of the gap between the electrode (11) and the workpiece (10) to occur. | - i IMPROVEMENTS IN METHODS AND APPARATUS FOR ELECTRICALDISCHARGE MACHINING The present invention relates to methods and apparatus for electrical discharge machining (EDM) otherwise known as spark erosion machining.EDM machining according to known techniques has proceeded n the basis that once sparking has been initiated in the gap between the electrode of an EDM machine and a workpiece, the sparking inevitably degenerates into arcing miless the discharge is interrupted for example by removing the voltage applied across the gap for a time sufficient to allow de-ionization in the gap. Thus the voltage is applied as a series of pulses which are usually of predetermined duration or the pulse continues until the integrated gap current has reached a predetermined value.The time taken for any machining operation is therefore considerably longer than theoretically necessary, since machining is not carried out in the intervals between voltage pulses.An object of the present invention is to reduce the time required to carry out EDM machining operations. According to a first aspect of the present invention there is provided an EDM machine comprising monitor means for providing a monitoring signal indicating the degree of sparking which occurs, during machining, in the gap between an electrode of the0MP1 machine and a workpiece, characterized in that the machine comprises control means for repeatedly carrying out first and second operations, the first operation being the substantially continuous application of a voltage between the electrode and the workpiece to provide sparking in the gap, and the second operation, commencing when the monitoring signal indicates a low degree of sparking, being the removal of the said voltage for a time at least approaching that required for de-ionisation in the gap. According to a second aspect of the present invention there is provided a method of electrical discharge machining comprising deriving a monitoring signal indicating the degree of sparking which occurs, during machining, in a gap between an electrode and a workpiece, characterized in that the method comprises repeatedly carrying out first and second operations, the first operation being the substantially continuous application of a voltage between the electrode and the workpiece to provide sparking in the gap, and the second operation, commencing when the monitoring signal indicates a low degree of sparking, being the removal of the said voltage for a time at least approaching that required for de-ionisation in the gap.The present inventors have carried out photographic observations on electrical discharge in machining and have discovered that the discharge between the electrode and the workpiece during a voltage pulse is made up of a plurality of separate sparks during good machining and that machining deteriorates when a voltage pulse includes a period of arcing.Previously, it was thought that each pulse started with a spark which gave way to an arc. The inventors' discovery allows the continuous application of a voltage between the electrode and the workpiece, to be interrupted following the occurrence of arcing as indicated by monitoring.Monitoring the discharge in the gap may be carried out by sensing energy emitted from the gap, for example by light radiation, or electromagnetic radiation (that is comprising the induction field and the radiation field) or as represented by the electrostatic or magnetic fields associated with voltages across, DΓ currents in, the gap, provided, of course, that the signals derived by sensing in these ways distinguish between arcing and sparking. Where electromagnetic radiation is sensed an antenna in the vicinity of the gap may be used, and signals in the frequency ranges 16 to 24 MHz and 26 to 60 MHz, at least, have been found to provide a good distinction between arcing and sparking since the amplitude of the signals received is much higher during sparking than during arcing, and falls as sparking approaches arcing.The differences in electromagnetic and light radiation from the gap are thought to be due to two mechanisms: firstly sparks are of comparatively short duration compared with arcs so that the rate of change of current in the gap is higher during sparking: and secondly, when iόnisation takes place in arcing and sparking the energy levels of electrons concerned change in different ways. With arcing, where a comparatively large amount of energy is supplied, more and greater energy level changes take place, re-combination takes place less frequently and with electrons taking up an intermediate state more often than in sparking. More energy level changes, as occur in sparking where less energy is supplied, mean greater magnitude and higher frequency electro-magnetic radiation, while more electrons taking up an intermediate energy level, as occur in arcing, mean more light emitted and light of different frequencies.In addition while during arcing light is generated substantially continuously, during sparking generation is intermittent and corresponds with the sparks. Thus the inter- mittent nature of light emission during sparking can be used to generate a monitoring signal.As another alternative in monitoring the discharge in the gap, a circuit may be connected directly or indirectly to the electrode and/or the workpiece to sense radio frequency signals in the voltage across the gap or the current in the gap. The amplitudes of signals in the ranges 5 to 10 MHz and 25 to 30 MHz have been found to be much higher during sparking than during arcing, and again these amplitudes fall as sparking approaches arcing. Other ways of distinguishing between sparking and arcing may be used, for example the voltage across the gap may be_0MPI monitored since there is a small reduction in this voltage when a change from sparking to arcing takes place.Certain embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Figure 1 is a block diagram of some electrical circuits of an EDM machine according to the invention, andFigure 2 shows waveforms appearing in the circuit of Figure 1. In Figure 1 an antenna 30 is located in the region of the gap 25 between an electrode 11 and a workpiece 10 of an EDM machine, or around a, tank which contains dielectric liquid in which the electrode and workpiece are submerged. The antenna is coupled by way of an amplifier 40 to a detector 4l which may simply comprise a series diode and a shunt capacitor. The amplifier 40 has an output signal amplitude dependent on input signal amplitude and preferably has a linear gain characteristic. The amplifier is frequency selective and is tuned to accept signals at about 30 MHz. The detect r 4l is coupled to one input of a comparator circuit 5 which also receives an adjustable reference level derived from a potentiometer 53- The output of the comparator 5 is connected by way of an OR gate 71 to a drive circuit l8' for a group of transistors 18 which when conductive apply current and voltage from a d.c. power supply 17 to the gap 25- An optionalIJUREAITOMPI , fa W1P0 ,Λ, rectangular waveform oscillator 19 is also shown in Figure 1 but the function and operation of this oscillator is described later.The output of the comparator 52 is also connected by way of an inverter 59 to trigger a pulse generator 70, which 10 milliseconds after receiving an input from the inverter 59 passes a pulse to the OR gate 71•In operation when machining is to be carried out, there is no spark across the gap and therefore practically no radiation at 30 MHz is received by the antenna 30. Thus the output of the comparator is zero and after a 10 millisecond delay the generator 70 is triggered to provide a pulse, which reaches the drive circuit 18' by way of the OR gate 71 and causes the transistor group 18 to conduct. Thus if conditions are correct for sparking, r.f. radiation at a high level commences and a signal from the comparator 5 maintains a signal causing the transistors of the group 18 to continue conduction. ' Sparking continues in the gap until, for example, an arc occurs at a time 73 in Figure 2 which is a waveform at the output of the OR gate 71• The signal from the comparator then ceases and the transistor group 18 immediately ceases to conduct. The waveform of Figure 2 now falls to zero and a ten millisecond interval ensues for the arc ionisation channel to disperse, the start of this interval being triggered by the comparator 52 by way of the inverter 59 and ending when the pulse generator 70 applies a start pulse to the OR gate 71- This process is continuous as indicated in Figure 2 where the level at the output of the OR gate 7 during sparking is designated 'sparking'. A further arc occurring at a time 74 is also shown together with the subsequent cessation and re-appearance of sparking.Clearly the advantage of the arrangement of Figure 1 is that very high machining efficiency can be obtained since there are no interruptions in sparking until arcs occur and then the interruptions are just sufficiently long for ionisation channels to disperse. The waveform shown inFigure 2 is by way of illustration and in fact, of course, sparking would occur for a much greater portion of any machining time. Provision is made for flushing the gap if arcing cycles of short period occur continually. Coarse and fine machining used at the beginning and end of a machining operation are often controlled by using long machining pulses to start and short pulses at the end. This adjustment is not available in the arrangement of Figure 1, since drive is applied at all times in which sparking occurs. However coarse and fine machining is achieved by adjustment of the power applied to the gap, for example by controlling the number of transistors in operation in the group l8.The arrangement of Figure 1 may include the oscillator 19 which has a rectangular output waveform. The function of this oscillator is to superimpose an oscillatory voltage, for example in the frequency range 50 to 100 KHz, on the gap voltage with the object of supporting the sparking condition. Since the oscillator 19 is connected in series with the group of transistors l8, it applies its output voltage to the gap 25 only when voltage from the supply 17 is also applied to the gap. In a typical arrangement the voltage applied across the gap by the d.c. supply is 85 volts and the superimposed voltage has an amplitude of 1 volts.The arrangements of Figure 1 can be further modified by replacing the d.c. supply 17 and the groups of transistors 18 and 19 by an SCR bridge (not shown) with an a.c. supply connected across two terminals and the electrode and workpiece connected across opposite terminals. The four SCRs of the bridge are then directly triggered by the output from the gate 7 b way of a drive circuit but of course only those correctly poled by the supply at that time conduct. The SCRs can be replaced by SCSs with the advantage that arcing can be made to cease directly it is detected by switching off those SCSs which are conducting. It will be appreciated that while specific embodiments of the invention have been described the invention can be put into practice in many other ways, for instance by using different circuits to distinguish between sparking and arcing and to control the application of voltage across the gap.0MPI rfa W1P0 | CLAIMS1. An E.D.M. machine comprising monitor means for providing a monitoring signal indicating the degree of sparking which occurs, during machining, in the gap between an electrode of the machine and a workpiece, characterized in that the machine comprises control means for repeatedly carrying out first and second operations, the first operation being the substantially continuous application of a voltage between the electrode and the workpiece to provide sparking in the gap, and the second operation, commencing when the monitoring signal indicates a low degree of sparking, being the removal of the said voltage for a time at least approaching that required for de-ionisation in the gap.2. An E.D.M. machine according to Claim 1 wherein the monitoring signal indicates when sparking has ceased, the second operation commences when sparking has ceased, and the said time is at least sufficient to allow de—'ionisation in the gap. 3* An E.D.M. machine according to Claim 1 or 2 wherein the monitoring means comprises an antenna positioned to receive electromagnetic radiation from the gap, and means for deriving the monitoring signal from signals received by the antenna.• 4. An E.D.M. machine according to Claim 1 or 2 wherein the monitoring means comprises an electrical connection to the electrode and/or the workpiece, and means for deriving the monitoring signal from signals received by way of the said electrical connection. 5. An E.D.M. machine according to Claim 1 or 2 including a d.c. supply connected, in operation, by way of switching means across the gap, characterized in that the control means comprises a comparator for providing a first contr signal when the monitoring signal is above a predetermined level, a pulse generator which, in operation, is triggered by the absence of the first control signal to generate a second control signal after a predetermined interval equal to the said time, and OR-gate means connected to receive the first and second control signals as inputs and to cause the switching means to conduct only when the first or second control signals are present.6. An E.D.M. machine according to .Claim l .or.*2 including a d.c. supply connected, in operation, by way of switching means across the gap, the control means controlling conduction by the switching means in accordance with the monitoring signal, characterized by comprising means for superimposing an oscillatory voltage on the voltage applied across the gap, the amplitude of oscillatory voltage being small compared with the magnitude of the voltage applied across the gap by the d.c supply.7. An E.D.M. machine according to Claim 6 wherein the repetition frequency of the oscillatory voltage is in the range 50 to 100 KHz.0 8. A method of electrical discharge machining comprising deriving a monitoring signal indicating the degree of sparking which occurs, during machining, in a gap between an electrode and a workpiece, characterized in that the method comprises repeatedly carrying out first and second operations, the first operation' being the substantially continiious application of a voltage between the electrode and the workpiece to provide sparking in the gap, and the second operation, commencing when the monitoring signal indicates a low degree of sparking, being the removal of the said voltage for a time at least approaching that required for de-ionisation in the gap.9. A method of electrical discharge machining according to Claim 8 wherein the monitoring signal indicates when sparking has ceased, the second operation commences when sparking has ceased, and the said time is at least sufficient to allow de-ionisation in the gap. | BHATTACHARYYA S; EL MENSHAWY M; NAT RES DEV; NAT RES DEV CORP | BHATTACHARYYA S; EL MENSHAWY M |
WO-1979000391-A1 | 1,979,000,391 | WO | A1 | XX | 19,790,712 | 1,979 | 20,090,507 | new | E04H12 | null | E01F9, E04H12 | E01F 9/018H | POST MOUNTING | This invention relates to a device for mounting posts or poles in a foundation. As shown in Figure 1c one design consists of supports (2) attached both to the casing (3) and to the flange of the post (1). Figure 1a shows the extra bend or bends (4) with which the supports are provided, one or more of which are stretched when the casing of the post is demolished by a vehicle. The invention is of particular advantage when applied to yielding posts or poles of thin sheet metal which are normally cut off when hit by a vehicle, the supports stretching and restraining both the post and the vehicle. | Post MountingPosts for lighting and road signs at the side of the roads are exposed to the risk of being hit by vehicles. This relates to the road environ¬ ment and its influence on damage in run-off accidents, for example. Lately, impact absorbing posts have been introduced, posts that are sufficiently soft or which break away and thereby reduce the collision forces that cause damage to road-users and vehicles.It has, however, been observed that objects hit by a vehicle can da¬ mage following vehicles if the object is torn loose and flung about out of control. Furthermore, a driver who has just hit a post is most often so shocked that he can hardly steer the vehicle if it continues to move on. It would, therefore, be of great advantage if the object that was hit could relatively gently restrain the vehicle. The area of application could be expanded and eventually go so far as to the placing of such yielding and restraining posts along the central reservation of highways without a need for guard rails.The present invention is a mounting device especially suited for yiel¬ ding posts, for example lamp posts,' but also suited for other posts located in the road environment.The post mounting is in itself able to yield (either by means of short bent supports, 'or supports going through the post, or by means of an energy-absorbing attachment such as a friction attachment,) so that for¬ ces occurring when a vehicle hits the post become as small as possible.Should a collision occur, the post casing becomes particularly heavily deformed at its base. Special measures are required to ensure that the post is not snapped off. The alternative of using a stronger design for the post itself is unsatisfactory, as the yielding of the post to the vehicle becomes too low. By anchoring the casing in supports or similar devices that in turn can yield under balanced resistance, it is possible to restrain both the post and the vehicle at the base of the post. The following describes a flange mounting of the post. When hit, the casing of the post is bent ~bγ the. vehicle to a flat shape along the ground, where the relatively thin shell of the casing splits and the post becomes partly or fully loosened at its base. The pre-shaped supports are fastened to the casing and readily follow the bending of the casing, but provide resistance when they are stretched lengthwise. They can therefore be designed to retain the post at its base even after the casing has been torn off by the vehicle.The supports serve as an anchoring device between the foundation and the torn-off post, with the result that both the post and the vehicle hitting it are retained.A variation of the energy-absorbing support can be obtained by using a tie plate perforated in a certain pattern. The pattern is made allowing the plate to be torn crosswise in certain parts, not completely, but so that untorn sections of the material retain the post at its base. This effect can for example be obtained by making rows of holes across the tie plate and alternatively omitting the last hole or holes in each row so that no rupture of the material occurs at these points. The distanc between the edges of the holes is relatively small and the plate breaks there when strained. A zig-zag shaped rupture pattern occurs. By adjust ing the accumulation of material, it is possible in this manner to ob¬ tain supports that moderate forces. Slots can be punched in the materia instead of the rows of holes. The tie plate can furthermore be designed as a tube-shaped support along the whole of the inside of the post.Figures 1 - 5 show supports for the connection between a flange 1 and the base of a post 3. 'Figures 6 - 9 show supports for mounting a post set in a foundation.Figure 10 shows a support device with perforated tie plate. Figure 11 shows an expanded support (as in Figure 1θ). Figure 12 shows a friction attachment at the foundation. Figure 1 shows supports fabricated from steel straps which are then welded to the inside of the casing at their upper ends and to the under¬ side of the flange at their lower ends. The support is formed with a special bend 4, in accordance with the concept of the invention. Figure 1a shows an individual support. Figure -1 b shows a support mounted on the flange 1 and Figure 1c shows six supports mounted in a post.Figure 2 - 4 show variations of the shaping of supports in the form of iron rods, fastened at one end to the inside of the casing and at the other in special holes in the flange.Figure 5 shows a variation consisting of a relatively thin tube 5 which is pressed together in its axial direction as a bellows 6. It is then fastened to the inside of the casing and to the flange. Its energy-absor¬ bing capacity is based on stretching of the tube in its axial direction.Figure 6 shows the same type of support as in Figure 1. The post is, how¬ ever, not provided with a flange, but is intended for bedding in a founda¬ tion. The supports are therefore fastened to a section 3 above ground on the casing, and a section 7 below the ground, and are bent in one or more i curves' etween these sections.Figures 7 - 8 show designs corresponding to Figure- 6, but using rod supports.Figure 9 shows the same design as in Figure 5, but with a compressed, slotted tube fastened to a section above ground and to a section below ground.Figure 10 shows a support device with tie plate 10 and rows of holes 11 which have the last hole omitted alternately. This provides a greater amount of material 12 at those points. The rows of holes can be replaced by slots.Figure 11 shows a support which has been stretched as the result of an accident. The material 13 between the rows of holes has ruptured, except at point 12 where the material was more solid. The tie plate has been stretched and constitutes an energy-absorbing anchor between the founda¬ tion and the casing of the post. Figure 12 shows an example of a post support with a continuous casi extending to the bottom of the foundation. The casing 3 of the post is slightly tapered and when stretched, an interaction occurs betwe the flange 1 and a core 14 set in the foundation.The designs shown here are by no means the only ones satisfying the concept of the invention. Variations can be made, for example, the supports can be located on the outside of the casing, they can be fastened by screw connections so that an energy-absorbing effect is obtained by means of friction, or they can be provided with some so of springs dimensioned for the purpose. | PATENT CLAIMS1. Mounting for hollow posts, poles and the like, placed at a roadside or similar location, characterized by yielding tensile strain supports (2), which are bent, shaped or friction bonded, and which are placed between a section of the casing (3) above ground and its flange attach¬ ment (1) or another section of the casing (7) below ground.2. Mounting according to Claim 1 , characterized by an arrangement of friction and profile locking connections that deform the casing when it is drawn out of the foundation.3. Mounting according to Claim 1. characterized by steel plates or rods welded to a section of the casing located above the ground and with one or more extra bends reaching down to the flange attachment, where the plates or rods are fastened by welding, or as an alternative, reaching down to a section below ground where they in like manner are welded to the casing.4. Mounting according to the former Claims, characterized by the fastening of an inner support arrangement consisting of a thin-walled tube (5) or other profile, to a section of the inner casing of the post above ground, and, with one or more corrugations (6), peripheral channels, slots (11)- or the like, extending to the flange attachment (1 ) to which the tube is then fastened, or alternatively, extending to a section (7) below ground and there fastened to the casing of the post, or forming the casing of the post below ground. | HASSELQVIST S; HELENELUND P; SCANOVATOR HANDEL; THORESON A; SCANOVATOR HANDELSBOLAGET | HASSELQVIST S; HELENELUND P; THORESON A |
WO-1979000402-A1 | 1,979,000,402 | WO | A1 | EN | 19,790,712 | 1,979 | 20,090,507 | new | B60S1 | null | B60S1 | B60S 1/38B2, L60S 1/38B2, L60S 1/38F4D | DE-ICING DEVICE FOR WINDSHIELD WIPERS | A device for de-icing windshield wipers and the like, and takes the form of an electric heating element (10) shaped as an elongate strip with substantially the same outside dimensions, and also to advantage with the same resiliency characteristics, as one of the spring strips normally inserted in longitudinal grooves on either side of a wiper blade to give it the necessary lateral stiffness and vertical springiness. This strip-like electrical heating element is intended for inserting in one of said grooves in the blade instead of the normal spring strip. The heating element is built up from an outer metal casing (13) having said strip shape and resiliency characteristics, and being provided with an internal axial duct in which an insulated (12) electric resistance wire (11) is disposed. At its one end, this resistance wire is connected to an electric supply lead at one end of the casing, while at its other end the wire is electrically connected to the casing in the vicinity of the other end of the latter, so that the casing can function as ground or return lead for the heating element. The outer metal casing can to advantage consist of a metal tube flattened to the rectangular shape of a normal strip. | DE-ICING DEVICE FOR WINDSHIELD WIPERSThe present invention relates to a device for de- icing windshield wipers of the kind disclosed in the preamble to the accompanying claim 1.The problem of removing ice from windshields on cars and other vehicles has been satisfactorily solved in the majority of cases a long while ago, usually by hot air being blown against the inside of the wind¬ shield. It is, however, well known that under certain weather conditions there is often heavy ice formation on the wipers, partly on the wiper blade of rubber or similar material, and partly on the articulated holder retaining the wiper blade along its spine and which is attached to the wiper arm. This ice formation causes the wiper blade itself to become stiff and to loose its required flexibility, deterioration in the necessary articulation of the holder, and deterio¬ ration in the necessary mutual ovability between wiper blade and holder in the longitudinal direction of the blade, all of this leading to the wiper blade no longer shaping itself to the windshield surface, which is usually curved, and the function of the wiper thus being seriously deteriorated. It may also occur that the iceformation on the wiper blade is so heavy that the latter is completely or partially lifted up from the windshield surface, the wiper function thus being disabled. It is also well known that the wiper blades on a stationary vehicle often freeze solid against the windshield. If the driver then loosens the frozen-on blades by hand before starting, it often occurs that the narrow edge of the blade is damaged, with sub¬ sequent deteriorated wiper function.A very large number of devices have been suggested for de-icing windshield wipers, primarily by using electrical heating. These previously proposed devices are burdened with many serious disadvantages, however, and none of them appears to have been put to any practical use either. 5.. In some of the previously proposed devices (those of the US Patent specifications 2 865 040, 3 201 818 and 3 428 993, for example) one or more electrical resistance wires are molded into .or inserted in longitudinal ducts inside the wiper blade itself. 0 This arrangement makes the manufacture of the wiper blades more complicated and thereby more expensive, which is a substantial disadvantage, since these blades are a consumption part which usually needs replacing comparatively often. The resistance wires 5 molded or inserted into the wiper blade also reduce the flexability of the wiper blade, which is necessary for a good wiping function. A device of this kind also results in that the heat is generated inside the blade itself, which is not what is really desired, 0 and which can also disadvantageously affect the rubber material in the blade.In other previously proposed devices (those in accordance with the US Patent specifications 2 686 247. 2 746 007 and 3 530 525, for example) insulated 5 electrical resistance wires or the like are fitted in exterior grooves on the wiper blade or on different parts of the holder means for the blade. These devices are, however, comparatively complicated to install, and they are furthermore easily subjected 0 to damage due to the small dimension of the resistance wires, especially when replacing a wiper blade which, as pointed out above, must take place relatively often and which is something that should preferably be possible for the vehicle owner himself to do. It has further been proposed in the German Published Specification 2 309 902 that the metal spring strips, which in a very common type of wiper blades are inserted in grooves formed on either side of the wiper blade along its spine in order to provide the blade with sufficient lateral stiffness and required springiness in height, are also utilized as electrical heating elements by having a current passed directly through these strips. Such an arrangement is not practically realizable, however, since it is difficult to. provide the necessary electrical insulation of these spring strips in a way that is simple and reliable at the same time. Furthermore, these strips have an electrical resistance which is much too low for them to be used as electrical resistance-heating elements. If the strips are con¬ nected to the normal voltage supply on the vehicle, which is usually 6 or 12 volt, very large current values are obtained and the generated power will be many times greater than what is necessary for the purpose.The object of the present invention is therefore to provide an improved device for de-icing a wind¬ shield wiper, which has a wiper blade of rubber or similar material and of the very usual type which is provided with a groove on either side of its spine, these grooves being intended to accommodate spring strips, substantially rectangular in cross section, for giving the wiper blade the necessary lateral stiffness and necessary vertical springiness.What primarily distinguishes the device in accordance with the invention is apparent from the characterizing portion of the accompanying claim 1. Advantageous embodiments and improvements of this device have the characterizing features disclosed in claims 2-13.The invention is thus based on the idea that at least one of the spring strips normally inserted in the grooves on either side of the wiper blade along its spine is exchanged for a strip-shaped electric heating element having substantially the same outside dimensions as said spring strip, and having the structure disclosed in the claims with a central, insulated electric resistance wire disposed in an outer strip-shaped metal sleeve or casing, which is preferably electrically connected at one end to the adjacent end of the resistance wire and which serves as a mechanical protection against damage to the insulated resistance wire and also as a ground or return conductor for the current through the resistance wire. Such a heating element in accordance with the invention can be manufactured very simply and cheaply and is also very resistant to outside damage. It is also just as easy to mount and remove as the normal spring strip which it is in¬ tended to replace, the exchange of wiper blades thus not being made more difficult in any way. If so desired, during seasons when there is no danger of ice formation, the heating element can easily be removed and the normal spring strip inserted instead. The heating element in accordance with the invention will also have such a location on the wiper that the heat generation occurs at the desired place, i.e. on the outside of the wiper blade and close to the most adjacent portions of the blade holder. The heating element can be easily manufactured in dimensions suited to different wiper blades, and by selecting the area of the resistance wire, it is easy to adjust the resistance of the element to a desired value. The invention will now be described in detail with reference to the accompanying drawing, on which there are shown as examples some embodiments of the invention, and whereFigure 1 is a schematic side view, of a common design of a windshield wiper,Figure 2 shows a portion of the wiper in Figure 1 to a larger scale,Figure 3 is a section along the line III-III in Figure 2, Figure 4 is a -side view of an embodiment of a heating element in accordance with the invention,Figure 5 is a sectional perspective view showing the construction of the heating element accord-. ing to Figure 4,Figure 6 is an axial section through one end of the element in Figure 4 at a certain stage of its manufacture,Figure 7 is an axial section through the other end of the heating element in Figure 4, at a certain stage of its manufacture,Figure 8 is an axial section similar o the one in Figure 7, but showing a somewhat different arrangement of the connections for the • current supply lead and the ground lead,Figure 9 is a schematic side view of another embodi¬ ment of a heating element in accordance with the invention, in which embodiment the metal casing is formed from two halves joined together, one of these halves being removed on the drawing, Figure 10 is a cross section through a heating element according to Figure 9 , with both halves of the outer metal casing shown spaced apart,Figure 11 is a view similar to the one in Figure 9 illustrating a further embodiment of the invention, and Figure 12 is an axial section through one end of a heating element in accordance with the invention, with a suitable form for the connection between the current supply lead and the resistance wire. Figures 1-3 show by way of example a very common design of a windshield wiper. This wiper comprises an elongate wiper blade 1 of soft rubber or similar material, and a holder assembly generally designated by the numeral 2, which is attached to the outer end of the wiper arm 3, only partially shown in Figure 1, and which retains the blade 1 along its spine. The holder 2 usually comprises, as in the example shown, a number of yokes 4 hinged to each other. The number of yokes can vary and is essentially dependent of the length of the blade 1. The outermost of these yokes 4 are provided with claws 5 grasping round the rear edge or spine of the blade 1, and with their tips gripping into two grooves 6 formed on either side of the blade 1. So that the very soft and easily deformable wiper blade 1 will have sufficient lateral stiffness, i.e. in the direction of the arrow 7 in Figure 3, and at the same time the necess¬ ary springiness or resiliency in vertical direction, i.e. in the direction indicated by the arrow 8 in Figure 3, there are two elongate spring strips 9 of substantially rectangular cross section and usually made of metal, inserted in corresponding grooves on either side of the blade 1 in the vicinity of its spine. These strips 9 have substantially the same length as the blade 1. In order that the blade 1 will be able to adopt itself to the varying curva¬ ture of the windshield when the wiper is in operation, so that the blade has the total length of its scraping edge engaging against the windshield the-whole time, the blade 1 must be movable in its longitudinal direction relative to all the claws 5 on the yokes 4 with the exception of one such claw. The blade 1 is usually formed with stops filling out the groove 6 at one end, these stops coacting with the claw 5 at the same end of the blade so that the blade is kept in place in its longitudinal direction at this claw. The blade 1 is freely movable in its longitu¬ dinal direction relative to all the remaining claws 5. In a corresponding way, the grooves in the-blade 1 accommodating the spring strips 9 are formed with a tap or the like which coacts with a notch in the strips 9, so that the strips are locked in their longitudinal direction. The strips are otherwise loose in their grooves in the blade 1 and are retained in these grooves by their being surrounded by the holder claws 5.In a de-icing device in accordance with the invention, at least one of said strips 9 is replaced by an elongate strip-like electric heating element 10, having substantially the same outside dimensions as the spring strip 9.Figures 4 and 5 show a first embodiment of such a heating element as an example. This element 10 consists of a central electric resistance wire 11 surrounded by an insulation consisting in the illu¬ strated 'embodiment of a tube 12 of a pliant plastic material, e.g. polytetrafluorethene, and an outer flattened metallic casing 13. All these parts of the - heating element extend for substantially the whole length of the element. At one end 10a of the ele¬ ment 10, the resistance wire 11 is electrically connected to the outer metallic casing 13. At the other end 10b of the element, the resistance wire 11 extends together with the insulation tube 12 out of the casing 13 for being connected in a suitable way (not shown in the drawing) to the supply lead from a current source. At this end 10b of the element there is also a return or ground lead 14, which is inserted into the end of the casing 13 between it and the insulation tube 12, and is in electrical contact with the casing 13, as will be more closely described in the following. At the end 10a, the element 10 can be formed with a notch 10c for fixing the position of the element in the groove in the wiper blade 1 in the same way as is described hereinbefore with respect to the normal spring strips 9. The desired resistance value for the heating element, and thus the value of the current flowing through it and its generated power, is determined by selecting the area of the resistance wire in re¬ lation to the length of the heating element, i.e. the length of the appropriate wiper blade. The di¬ mensions of the outer flattened metal casing 13 are selected so that the cross-sectional form of the heating element 10 substantially coincides with that of the normal spring strip 9, which the heating element is intended to replace. The casing 13 should naturally consist of a metallic material which is a good heat conductor and -also a good electrical conductor. Practically all conceivable metallic materials are satisfactory from this point of view. The casing 13 should further consist of a metallic material which is sufficiently resistant to corrosion, or alterna¬ tively it can be provided with a corrosion resistant surface layer. The casing 13 can to advantage be manufactured from a resilient metallic material so that the heating element 10 is given substantially the same resiliency characteristics as the normal spring strip 9 which the element is intended to replace. If only one spring strip 9 in the wiper blade 1 is replaced by a heating element in accord¬ ance with the invention, which in most cases is sufficient for the de-icing, the casing 13 in the heating element does not necessarily need to consist of a particularly resilient material, since the remaining normal spring strip 9 in the wiper blade will provide it with the necessary resiliency, and the casing 13 can consist of a comparatively pliant and flexible metallic material, advantageous from other points of view, such as aluminium.The heating element according to Figures 4 and 5* can to advantage be manufactured such that a resistance wire 11 is thrust into an insulation tube 12 so that one end of the resistance wire 11 projects a distance outside one end of said tube'. The resist¬ ance wire 11 together with the insulation tube 12 is then thrust into a circular metallic tube of a length corresponding to the finished length of a heating element and with a suitable diameter and wall thick¬ ness , it being ascertained that the uninsulated end of the resistance wire 11 is within one end of the metal tube while the other end of the resistance wire 11 together with the insulation tube 12 projects out from the other end of the metal tube. The metal tube is then flattened along its entire length into the cross-sectional shape desired for the heating element, so that the resistance wire 11 together with the insulation tube 12 are clamped inside the flatten¬ ed metal casing 13 and so that the uninsulated end* of the resistance wire 11 is brought into electrical contact with the casing 13 at one end thereof.As illustrated in Figure 6, before compressing the casing 13 a short piece of metallic tube 14 can be pushed into said end of casing 13 round the un¬ insulated portion of the resistance wire 11. At the subsequent compression of the casing 13 this tubular piece 14 contributes to a secure electrical contact between the resistance wire 11 and the casing 13. The outer end 10a of the heating element 10 is furthermore reinforced by this means, so that the notch 10c shown in Figure 4 can be cut out of the heating element without detriment. At the other end of the heating element, an end of the return or ground lead 14, from which the in¬ sulation has been removed, can be thrust into the outer casing 13, between it and the insulation tube 12 surrounding the resistance wire 11, before com- pressing the casing 13 so that when this compression subsequently takes place the ground lead 14 is clamped firmly and brought into secure electrical contact with the casing 13. It will be observed that the outer metal casing 13 of the heating element will serve as a return conductor for the current through the resistance wire 11. Since the resistance of the casing 13 is very much less than the resistance of the resistance wire 11, the voltage drop across the casing 13 will be very small, and therefore electrical insulation of it is not required.- The casing 13 will naturally be able to come into contact with* the retaining claws 5 on the yokes 4 which are generally made of metal. There will thus be a certain amount of current flowing from the casing 13 to the retainer claws 5 and the holder yokes 5, but this does not constitute any essential disadvantage. For secure grounding of the casing 13 and secure return flow of the current through the heating element, it is, however, prefer¬ able that said element is provided with a return or ground lead 14 connected to the casing.In the embodiment of a heating element in accord- ance with the invention shown in Figures 4, 5 and 7 and described above, there is a certain risk of mechanical damage to the insulated wire 11/12, and even to the ground lead 14 at the end of the casing 13, since the resistance wire 11 and the ground lead 14 are subjected to such fatigue stresses due to vibrations that rupture or at least insulation damage may occur. This risk is substantially reduced in the embodiment schematically shown in Figure 8, where the outer metal casing 13 is not flattened into the shape of the flat strip over a short portion 13B outermost at the end 10B of the heating element, where the casing 13 is thus allowed to retain its substantial¬ ly circular cross-sectional form. Within this end postion 13B of the casing 13, the resistance wire 11 is joined in a suitable way, e.g. by soldering with an insulated electric supply lead 15 of a conventional kind, which extends a dis- tance into the end of the casing 13. The joint bet¬ ween the resistance wire 11 and the supply lead 15 can to advantage be insulated by a sleeve of plastics tube 16, as in the illustrated embodiment, and this tube can extend a distance outside the end of the casing as shown on the drawing, whereby the plastics sleeve 16 will serve to protect against mechanical damage and as an insulation reinforcement at the outer end of the casing 13, where the risk for insu¬ lation damage and fatigue rupture to the electrical conductor is greatest.In this embodiment of a hetaing element in accordance with the invention, the ground lead 14 is attached in a suitable manner, e.g. by soldering or welding, to the outside of the casing 13 close to its end, so that both electrical leads 14 and 15 for the heating element can be extended parallel and together from the wiper blade.In the embodiments of a heating element in accord¬ ance with the invention described above, the outer metallic casing has consisted of a metal tube, which has been flattened to the desired strip shape after insertion of the insulated resistance wire. This appears to be a simple and advantageous method of manufacturing a heating element according to the in- vention. However, there is nothing to prevent the outer metal casing of a heating element in accordance with the invention being manufactured with the desired strip shape from the beginning, it then being provided with one or more internal axial ducts in which the insulated resistance wire is inserted. Such a strip¬ like metallic casing could be manufactured by ex¬ trusion, for example. It is also possible to form the outer strip- shaped metal casing from two halves which are put together as shown by way of example in Figures 9 and 10. In the embodiment of a heating element in accord¬ ance with the invention shown here as an example, the outer metal casing consists of two strip-shaped halves 13a and 13b, which can be joined in the way shown in Figure 10, and of which at least one is formed with a groove 17 to provide an axial duct when both strip halves are put together, in which duct the insulated resistance wire 11, 12 can be inserted. Both strip halves 13a and 13b can further¬ more be formed with complementary recesses and pro¬ jections 18 as well as guide pins 19 and mating holes, which facilitate the assembling of the strip halves. They can be kept together by welding or by glueing. As shown in Figure 11,. a heating element of this kind can also be provided with a notch 10c at one end, for locking the heat element in the wiper blade groove. Figure 11 also shows how the electric supply lead 15 can project a distance into the central duct 17 in the outer strip-shaped metal casing and be joined here to the electric resistance wire 11.Figure 12 shows schematically how the junction 19 between the lead 15 and the resistance wire 11 can be accommodated in an expanded portion 13B of • the strip-shaped casing 13. This expanded portion 13B can be formed in one piece with the two strip halves 13a and 13b. Other embodiments of a heating element in accord¬ ance with the invention are naturally possible further to those described hereinbefore. Thus, the materials for the resistance wire 11, the resistance wire insulation 12 and the casing 13 can be varied and selected differently depending on different require¬ ments. One can naturally use an electric resistance wire which has already been provided with suitable insulation during manufacture. A device in accordance with the invention can of course also be used for de-icing wiper blades on headlights, vehicle rear windows and the like. | C L A I M S :-1. A device for de-icing a windshield wiper, which has a wiper blade (1) made from rubber or similar material and formed with two grooves substantially extending the entire length of the blade one on either side thereof, in which elongate spring strips (9) with a substantially rectangular cross section are intended to be inserted for providing the blade with sufficient lateral (7) stiffness and sufficient vertical (8) resiliency, said device comprising an electric heating element (10) which can be mounted on the wiper blade (1), characterized in that said heating element (10) is formed as an elongate strip having substantially the same outside dimensions as said spring strips and intended for insertion in one of said grooves in the wiper blade (1) instead of such spring strip, this strip-shaped heating element (10) being built up from an outer metallic casing (13) with said strip-shape, said casing having at least one interior duct extending axially at least over the greater portion of the casing length, in said duct there being disposed an electric resistance wire (11) provided with insulation (12), said wire being electrically connected at one end to an electric supply lead (15) and at its other end to a ground connection.2. A device as claimed in claim 1, characteriz¬ ed in that the outer metal casing (13) consists of a resilient metal material so that it has substantial the same resiliency characteristics as said spring strip (9). 3. A device as claimed in claim 1 or 2 , characteriz¬ ed in that the resistance wire (11) is electrically connected to the electric supply lead (15) at, or in the vicinity of, one end (10B) of the outer metal casing, while at its other end it is electrically connected to the casing (13) at the other end ( 10A) thereof, so that the casing serves as a part of the ground connection.4. A device as claimed in any of claims 1-3, characterized in that an electric ground lead (14) is connected to the outer metal casing (13) at its said one end (10B).5. A device as claimed in any of claims 1-4, characterized in that the casing consists of a metal pipe (13) flattened to a substantially rectangular cross sectional shape after inserting the insulated resistance wire (11).6. A device as claimed in claim 3 or 5, characteriz¬ ed in that the electrical connection between said second end of the electric resistance wire (11) and the outer metal casing (13) at said other end (10A) of the latter consists of a short piece (14) of metal pipe surrounding the uninsulated end of the resistance wire, said pipe piece (14) being inserted and firmly clamped in the end of the casing (13).7. A device as claimed in claim 5 or 6 , characteriz¬ ed in that an electric ground lead (14) is inserted a distance into the outer metal casing (13) at said one end (10b) of the latter and clamped firmly therein.8. A device as claimed in any of claims 1-4, characterized in that the outer metal casing is put together from two strip-shaped halves (13a, 13b) substantially rectangular in cross section, of which at least one is formed with a longitudinal groove (17) in its flat side facing towards the other half, said groove (17) forming said duct for the insulated (12) resistance* ire (11).9. A device as claimed in claim 8, characterized in that both strip halves (13a, 13b) are formed in their opposing and connected sides with complementary recesses and projections (18) engaging each other and contributing to the union of both strip halves.10. A device as claimed in any of claims 1-9, characterized in that the insulation of the resistance wire (11) consists of a tube (12) of plastics material surrounding said wire.11. A device as claimed in any of claims 1-10, characterized in that said one end of the insulated resistance wire (11) extends out from the outer metal casing (13) at said one end (10B) of the latter and is electrically connected to the electric supply lead outside the casing.12. A device as claimed in any of claims 1-10, characterized in that the electric supply lead (15) projects a distance into the outer metal casing (13) at said one end (10B) of the latter, and is electircal- ly connected to said one end of the resistance wire (11) inside the casing (13). 13. A device as claimed in claim 12, characterized in that the inner duct in the outer metal casing (13) has an expanded portion (13B) therein accommodating the joint between the resistance wire (11) and the electric supply lead (15). | OHLSSON A; OLANI L | OHLSSON A; OLANI L |
WO-1979000406-A1 | 1,979,000,406 | WO | A1 | EN | 19,790,712 | 1,979 | 20,090,507 | new | D06P1 | C08J3, C08L67, C08K9, C08L95 | C08J3, C08K9 | C08J 3/22L, C08K 9/00 | MASTER BATCH TO BE ADDED TO A THERMOPLASTIC RESIN | Master batch to be added to thermoplastic resin, which can be used universally. Additive particles are dispersed in a vehicle comprising an aromatic resin which can be dispersed in the thermoplastic resin, and/or a modified alkyd free from oil. | MASTER BATCH TO BE ADDED TO A THERMOPLASTIC RESINThe present invention relates to a master batch to be added to a thermoplastic resin, including additive particles dispersed in a vehicle- Regarding such a master batch supplied in pelleted or granulated form, the requirement is that the master batch has a granular size which is commensurate with the granular size of the thermoplastic resin (basic raw material) which the master batch is to be mixed with.The reason for the requirement of the same granular size as that of the basic raw material is i .a. that granules of smaller size than the granules of the basic raw material fall through in the material magazine of the machine wherein the material is being used such as an injection moulding machine or an extruder and thus provide a higher concentration of the additive in the lower portion of the magazi ne .than in the upper portion thereof. The material falling through in this way is due to movements of the material in the magazine during the supply thereof to the plasticizing unit of the machine as well as occurring shaking and vibration of the machine.Another requirement regarding the master batch is that it should be possible to use it not only together with basic raw materials of an arbitrary granular size but also together with different types of thermoplastic resin. The master batches made to-day are intended for a specific type of thermoplastic resin the adjustment of the master batch to different types of thermoplastic resin being made by using different types of vehicles in the master batch. It is common that the thermoplastic resin used as vehicle in the master batch is the same as that which the master batch is to be mixed with. Thus, if a product is to be made of PVC this material is also-BU REA UO.V.PI used as vehicle in the master batch, and if the product is to be made of polystyrene or polyolefine the vehicle used is polystyrene and polyolefine, respectively, and so on. Accordingly, a big selection of master batches is required in order to cover the different needs that may arise in the production of thermoplastic resin products, i.e. one type of master batch for each type of thermoplastic resin, and con¬ sidering the fact that there is a choice of several different thermoplastic resins when manufacturing products of different types, this means that the plastic manufacturers have to keep a stock of different types of master batch the number of which is the same as the number of thermoplastic resins used. Confusion may easily occur and may be fatal because a master batch having a vehicle of a specific thermoplastic resin cannot be mixed with other thermo¬ plastic resins.The invention relates particularly to a master batch in the form of a toner including colour pigment particles as an additive said particles being dispersed in the vehicle. Other examples of additives or fillers which can be included into the master batch are UV stabilizers, lubricants, organic peroxides, pi asticizer heat stabilizers and flame-resistant agents. Particularl as far as additives are concerned, which are of the typ having two or more components, such as foaming agents, it may be important that at least one of the components is supplied and added as a master batch. Several additives can appear in one and the same master batch, e.g. colour pigments in combination with other fillers.Master batches in the form of a toner are manu¬ factured in such a way that there is added to the vehicl which thus has been chosen with regard to the intended use of the toner, between 20 and 50 per cent by-BOR i. weight colour pigment particles together with certain lubricants. This mixture is plasticized in an extruder and is pelleted or granulated to a toner (master batch) intended especially for the thermoplastic resin included in the toner. The toner thus produced is then used for colouring the thermoplastic resin used as a basic raw material in the plastic product factory where the final product is being manufactured the toner being added in an amount of 1 or 2 per cent in order to obtain the desired colour shade of the final plastic product. It should be mentioned here that besides the • colouring of the basic raw material by the use of a toner including colour pigment particles dispersed in a vehicle the .so-cal 1 ed dry colouring exists which implies that colour pigment particles are added in the plastic product factory directly to the thermoplastic resin used as basic raw material , by means of a mixer so that the comminuted colour pigment adheres to the granulated plastic resin. However, this method is objectionable from an environment point of view because the colour pigment creates an unhealthy dust emission. A supply of the colour pigment to the basic raw material , which is completely free from dust, therefore is aimed at to-day and in this respect the use of a toner of the type referred to herein has proved to be preferable.As would be clear from the discussion above there is, however, a need for a master batch, e.g. a dust- -free toner, which can be used universally for different types of thermoplastic resin s.o that the many different types or qualities which exist now can be reduced to a single type and quality. The requirements that have to be set regarding the vehicle of such a master batch that can be used universally as an additive to thermo¬ plastic resins are primarily as follows: l . The vehicle should be able to absorb additive par-OMPI tides up to 50 - 70 per cent of its own weight.2. The vehicle should have a pi asticization temperature below the plasticization temperature of the thermoplastic resin used as basic raw material , and latest at a temperature at the plasticization temperature of the basic raw material it should have a lower viscosity than the basic raw material.3. The vehicle should be able to supply the additive to the basic raw material and should be able to be dispersed therein without appreciable effect on the physical or chemical properties of the final product.4. The vehicle should have a coherent structure in cold condition so that the product can be pelleted or granulated to the same size as the basic raw material.5. The vehicle, moreover, should have a lubricat¬ ing or stabilizing effect. According to the invention, it has been found that a master batch which can be universally used as an additive to thermoplastic resin can be obtained, compris ing additive particles dispersed in a vehicle, wherein the vehicle provides the five properties listed above, if the vehicle comprises an aromatic resin which can be dispersed in the thermoplastic resin, or a resin modifie alkyd which can be dispersed in the thermoplastic resin, of the nature otherwise appearing from the characterizin cl ause of claim 1. The invention will be described in more detail belo with reference to illustrative examples.EXAMPLE 1 A suitable vehicle in a toner according to the invention as far as dark colour shades are concerned is the aromatic resin marketed by AB Nynas-Petrol eu under the registered trademark Nyomer. This aromatic resin is manufactured by the method described in the Swedish patent specification 7406252-2 and the addition thereof 7512352-1 , and it has such a molecular composition that it can be dispersed to the necessary extent in the great majority of thermoplastic resins presently known without significantly impairing the original properties of the basic raw material wherein the toner containing Nyomer is being dispersed. In producing the toner according to the invention colour pigment particles of the desired colour are dis¬ persed in a vehicle comprising Nyomer in a conventional manner the colour pigment comprising 50 to 70 per cent of the weight of the vehicle depending on the shade desired. The mixture of colour pigment and vehicle is plasticized in an extruder and pelleted or granulated in a conventional manner. The toner thus obtained has been found to have a dispersing, lubricating and stabilizing effect when added to the thermoplastic resin used as basic raw material .Nyomer per se is dark brown and therefore the use thereof as a vehicle for colour pigment particles is limited to dark colour shades. On the other hand, it then provides a reduction of the costs thanks to the fact that it contributes to the colouring the consump¬ tion of expensive colour pigment material thus being reduced .A prob.lem encountered in outdoor use of e.g. brown colour shades is the limited resistance of the plastics material to heat due to sun radiation. The increased heat absorption of the plastics material i.a. if it has a brown tint provides plastic movements in the material so that the product often will change its form due to equalization of inherent strains in the material . One reason for form changes at sun radiation particularlyUU EAZΓOMPI of products having a brown tint is the fact that iron oxide pigments are included. Plastics material coloured with brown toner according to the invention, which does not contain iron oxide but is given its colour solely by the vehicle comprising Nyomer, has been found to be shape-permanent for outdoor use and, moreover, the colouring of the plastics material obtained by such a toner is light-proof. The toner according to the invention thus is a good UV stabilizer against bleaching of given colour shades due to the ultraviolet rays con- • tained in the sunlight.Nyomer has a further property when used as vehicle in a toner i.a. as far as rigid PVC is concerned. In that case, the vehicle constitutes a so-called high- -molecular plasticizer, which means that the vehicle has the property of plasticizing rigid PVC at the plasticization temperature without a corresponding plasticity arising in cold condition. Rigid PVC thus remains rigid at normal temperatures of use but the vehicle has the ability to plasticize the PVC in the stage of plasticization at the plasticization temperatur which facilitates the supply of the colour pigment and also facilitates the plasticization of the basic raw material without the final product being plasticized. Because rigid PVC definitely is most difficult to handle of modern thermoplastic resins presently known and because Nyomer influences rigid PVC as men¬ tioned above it can be concluded therefrom that the function is the same as far as most other thermoplastic resins are concerned.Summarizing, it thus can be established that the use of Nyomer or other similar aromatic resin within the scope of the invention as defined in the claims provides a dust-free toner which can be used universally and in which the vehicle constitutes an internal as well as an external lubricant when the toner is supplied and dispersed. The toner, moreover, operates as a stabilizer against deterioration of the final product in some cases and as strain equalizing stabilizer in other cases in order to relieve strains that otherwise could be embodied in the product proper during the transition thereof from plastic condition to cold condition. Moreover, the vehicle operates as a high-molecular plasticizer, particularly in connec- tion with rigid PVC.EXAMPLE 2 In a toner according to the invention in case of light and snow-white colour shades where Nyomer cannot be used the resin-modified alkyd which is marketed by Bergviks Hartsprodukter AB under the trademark Berigid 100 is a suitable vehicle. This resin-modified alkyd is produced by the method described in the Swedish patent specification 356,060 and although it has been developed primarily to be mixed with polyvinyl chloride material it has been found that it is suitable also for addition to entirely different plastics materials such as polystyrene and polyethylene.For example a white pigment can have the following composition when Berigid 100 is used: White colour pigment, Ti O 30 % Berigid 100 35 % Tall oil 10 % EVA 20 %Stearic acid 2.5 % Calcium stearate 2.5 %The stearic acid prevents the thermoplastic resin from adhering in the machine in which it is worked. The stearate which can be e.g. calcium, zinc or aluminium stearate improves internal and external lubrication of the thermoplastic resin. The production of the toner by applying this recipe can be performed in the same manner as described above in connection with the use of Nyomer.Berigid 100 per se has a plasticization temperatur of about 110°C and can be modified as stated below in order to obtain different plasticization temperatures: For plasticization temperature 71°C Berigid 100 70 % Tall resin 20 % Tall oil 1 0 %For plasticization temperature 67°C Berigid 100 67 . 5 % Tall resin 20 % Tall oil 1 2 . 5 % For plasticization temperature 62°CBerigid 100 65 % Tall resin 20 % Tall oil 1 5 %To the mixtures listed above there can be added colour pigment particles in a concentration which is more than 50 per cent. If required, also some wax can be added.Berigid 100 can also be modified in order to chang the plasticization temperature thereof by adding ethyl- vinyl acetate (EVA) or a similar polymer. For example EVA can be obtained from Du Pont de Nemours under the trademark Elwax in different variants which influence the plasticization temperature in different ways. For example the following modifications of Berigid 100 can be obtained:For plasticization temperature 80°CBerigid 100 70 %Elwax 220 30 % For plasticization temperature 110 CBerigid 100 70 %Elwax 150 30 %For plasticization temperature 130°C Berigid 100 70 %Elwax 240 30 %In these modifications the change of the plasticization temperature obtained is dependent on the ratio between ethyl and vinyl in the ethylvinyl acetate polymer (Elwax).Berigid 100 and Nyomer have such properties that they can be mixed with each other as far as specific colour shades are concerned. To a toner which is based on Berigid 100 Nyomer thus can be added in order to obtain a darker colour shade. It may be of interest to add to a toner which is based on Nyomer, Berigid 100 in order to obtain a higher finish, improved gelation effect and increased capacity. In the latter case it is sufficient with an addition of 5 to 30 per cent to the total Nyomer recipe which then may contain up to 50 per cent carbon black. At such a high toner con¬ centration gelation aid is of extremely great importance.The modified mixtures with Berigid 100, mentioned above also lower the plasticization temperature of Nyomer in case it is included in the toner, the property of Nyomer acting as a universal vehicle being maintained.By the master batch according to the invention the following advantages are obtained:1. The master batch can be used universally in known thermoplastic resins.2. By the addition of the master batch the surface finish of the final product is improved because the surface will be smooth and brilliant due to the fact that the thermoplastic resin flows more easily. The surface obtained is-BUREAU_ 01ΪLF5 well suited for heat embossing and screen printing.3. By the addition of the master batch the - strength and other physical properties of the final product are improved due to an improved mixing and gelation of the thermo¬ plastic resin.4. The master batch has a rheol ogy-i proving effect, i.e. it facilitates processing. 5. The vehicle is non-toxic because it does not contain heavy metals or other constituents which are known to be toxic.6. The water absorption of the final product is reduced, which in turn involves an improved cold resistance.7. The final product has improved shape perma¬ nence.8. The final product has improved durability due to reduced outward migration of additive and thereby is better suited for contact with food-stuffs and less dangerous for those who work with the product e ve ry day (some additive can be toxic per se) .9. A product which has been coloured with a toner in the form of a master batch according to the invention does not give its colour off. 10. The master batch can be used in regenerating plastics scrap in order to improve the proper¬ ties of the generate by having a positive influence on the reconstruction of the polymer or the polymers of the plastics scrap, probabl by initiating a polymerization or in similar ways . The master batch according to the invention can include any additive for the addition of these additives-^UO to a thermoplastic resin, but the invention primarily has been developed for master batch in the form of a toner wherein the additive comprises solely a colour pigment or a colour pigment combined with other additives for influence on the properties of the thermoplastic resi n. BU EAUOMPI | CLAIMS1. Master batch to be added to a theromopl astic resin, which can be used uni versal ly, compri si ng additive particles dispersed in a vehicle, c h a r a c t e r - i z e d in that the vehicle comprises an aromatic resin which can be dispersed in the thermoplastic resin and is produced of an oxidized mineral oil distillate and/or an oxidized solvent extract of mineral oil distillate including aromatically bound carbon, the ' content of the aromatic compound corresponding to a minimum VGC value (VGC = Viscosity Gravity Constant) according to ASTM D 2140 of 0.85 and having an average molecular weight of 150 to 600, and/or an alkyd free from oil and modified by esterifi cation of resin acids, which has been produced of a resin material including more than 95 per cent by weight of free resin acids, and which has a minimum plasticization temperature of 90°C as measured according to the ball-and-ring method.2. Master batch according to claim 1, c h a r a c t e i z e d in that the amount of additive particles comprises 5 to 80 per cent, preferably 30 to 70 per cent, of the vehicle weight.3. Master batch according to claim 1 or 2, c h a r a c t e i z e d in that it is granulated to a granular size which is substantially commensurate with the granular size of the thermoplastic resin to which the master batch is to be added.4. Master batch according to claim 1 wherein the vehicle comprises the modified alkyd, c h a r a c t e r i z e d in that the alkyd is mixed with ethyl vinyl acetate polymer or a similar polymer for controlling the plasticization temperature of the alkyd.5. Master batch according to any of claims 1 to- -■4, c h a r a c t e r i z e d in that it has the fo of a dust-free toner including colour pigment particles BUO as additive, for colouring the thermopl astic resi nIJUREIΓOMPI | AKESSON T; ROSEN K | AKESSON T; ROSEN K |
WO-1979000411-A1 | 1,979,000,411 | WO | A1 | EN | 19,790,712 | 1,979 | 20,090,507 | new | F16F9 | B60G11 | B60G11, F16F9 | B60G 11/27, F16F 9/05, L60G 202/143, L60G 202/152, L60G 204/4502 | AIR SPRING ASSEMBLY | A heavy duty rolling lobe air spring (12), especially for trucks and trailers, which has an open hollow piston (32) providing a reservoir (34) and an outer surface on which the lobe of a flexible sleeve (18) rolls. The surface includes a horizontal top (42), a gently curved outer surface (43) joining an inverted frustro-conical side (44) and terminating in an outwardly flared bottom portion (48). Previous rolling lobe air springs adapted for heavy design loads have a high spring rate which fails to provide a soft, smooth ride only achieved in air springs having a low spring rate. The rolling lobe air spring (12) achieves a low spring rate providing a soft, smooth ride for heavy design loads. The side surface (44) has an angle with respect to the axis of the piston (32) of about 23`. The volume of the piston (32) and sleeve (18) of 850 to 1500 cu. in. (13,900-24,600 cu. cm.) and the angle of the frustro-conical surface (44) are such that the effective area of the sleeve (18) decreases under jounce and the spring rate is in the range of 100 to 300 pounds per inch (17.5-52.5 KN/m) at a design load in the range of 1000-8000 pounds (454-3629 kg). | AIR SPRING ASSEMBLYTechnical FieldThis invention relates to air springs. In one of its aspects, the invention relates to an air spring of the rolling lobe type wherein flexible sleeves are expanded to the maximum diameter under load and deflections due to bumps and the like are taken up through rolling of an end of the sleeve on a piston or pedestal which telescopes within the sleeve.Background ArtAir springs are well known in suspension systems for vehicles, especially heavy duty trucks and trailers. One particular type of air spring, known as the rolling lobe air spring, is disclosed in the Hirtreiter U.S. patent No. 3,043,582 issued July 10, 1962. This type of an air spring includes an expandible fabric sleeve which is expanded to a predetermined maximum diameter under load and a piston or pedestal, which is secured to one end (usually the bottom end) of the sleeve, tele- scopes within the sleeve. The sleeve is made of a plural¬ ity of ply of rubber and crossed sets of inextensible cords which run the length of the sleeve but are at an angle with respect to the axis of the sleeve. As the sleeve is expanded, the crossed sets of cords pantograph to an equilibrium angle of about 54°.Normally, under load, the sleeve is pressurized to a pressure of, for example, 30-50 psig (2.2 - 3.4 atm.) so that the load is supported through the sleeve assembly. A portion of the sleeve expands to the equilibrium angle of the cords and the piston or pedestal telescopes into an end of the sleeve, thereby forming a lobe which rolls on the pedestal when the spring is compressed. In this type of air spring, the spring rate, i.e. the change in the load per unit of deflection, is controlled by the shape of the pedestal. Hirtreiter discloses, for example, pedestals which have cylindrical sides, inverted frustr conical shapes and hourglass shapes.In the air spring assemblies incorporating those pedestals which have a decreasing diameter lobe rolling surface, the effective diameter of the air spring de¬ creases under compression, thereby providing a lower spring rate and a smooth ride. Generally, the lower the spring rate, the softer the ride. Thus, the softes ride would be achieved by a spring having a very low spring rate at design load. Spring rates at or near 0, or even negative spring rates, are theoretically possible but are not preferred because of the control systems which are used to pressurize the springs to maintain a design height. Certain rolling lobe air springs (for example GY 1100, assembly part No. 566-22-2-005) manufactured and sold by Goodyear Tire and Rubber Company of Akron, Ohio U.S.A. , have hourglass type of pedestals through which the effective area of the spring is decreased during compression. Further, the pedestal is open to the interior of the cylinder to provide an additional volume for the air spring. However, the spring rate is fairly high, for example, 1275 pounds per inch (22.30 KN/m) at 7200 pounds (3260 kg), and the load to spring rate ratio is about 5.6 in. (14.2 cm). Generally it is desirable to achieve a much lower spring rate, generally in the range of 100 to 300 pounds per in. (17.5 - 52.5 KN/m) and to achieve higher loads to achieve optimum operating conditions in heavy duty trailer and truck tractors. Heretofore, spring rates and ratios of load to spring rate in these ranges for heavier loads have not been obtained and wer thought to be unattainable, although theoretically poss ble for rolling lobe air springs. Another type of air spring purported to attain a minimum spring rate is a reversible diaphragm air sprin disclosed in the U.S. patent to Bank, 3,078,085, issued February 19, 1963. This type of air spring has a reser at the top and a flexible sleeve secured at an upper por¬ tion to the reservoir and at a lower portion to an hour¬ glass shaped pedestal. The lower portion of the sleeve is of a smaller diameter than the upper portion so that it telescopes therethrough during normal operation. The maximum inward convergence angle of the Bank pedestal is purported to be 19°. However, the effective area of the spring decreases during deflection at design loads so that a relatively low spring rate is achieved. However, the lobe of the Bank sleeve changes in size under compression because the sleeve is not fully expanded under load. The Bank spring is made for a relatively small load, for example, 1000 to 2000 pound range as would be provided in automobiles. in order to achieve the higher loading capabilities with the Bank type of spring, the size of the spring would have to be increased so that the volume is also increased. However, the volume of the spring has profound effects on the spring rate at higher loads and thus merely increasing proportions of the Bank spring will not necessarily result in the attainment of the same characteristics as in the smaller proportioned spring.Disclosure of Invention I have now discovered an air spring of the rolling lobe type which is adapted for heavy loads, for example, 5000 to 10,000 pounds (2268 - 4536 kg) but nevertheless achieves spring rates in the range of 100 to 300 pounds per inch (17.5 - 52.5 KN/m) with load-to-spring rate ratios in the range of 20 to 120 inches (50 - 300 cm) for these loads.The invention is applicable to those types of air springs wherein a hollow elastic sleeve is made from a plurality of ply of elastic material with sets of crossed inextensible cords which limit the expansion of the sleeve through pantographing movement to an equilibrium angle at a design load. The air springs have means for securing an upper end of the sleeve to a vehicle frame and a hollow piston adapted to be secured to a vehicle axle*and mount- ing a lower end of the sleeve. The piston provides an outer surface on which the lower end of the sleeve rolls in compression and rebound. Further, a reservoir in communication with the interior of the hollow sleeve is formed within the interior of the hollow piston.The invention is also applicable to air springs which have an expandable rubber sleeve which is otherwise restrained at a maximum diameter, as for example, by a metal sleeve.According to the invention, the exterior surface o the piston provides an outwardly extending top surface, adjoining a relatively large radius, downwardly curved surface on which the lobe of the hollow sleeve rests during normal loading condition. An inverted frustro- conical surface extends downwardly from the downwardly curved surface and provides an area of increasingly reduced diameter for the rolling lobe of the hollow sleeve during jounce. The angle of the frustro-conical surface and the volume of the air spring (including the hollow piston) are such that the ratio of load to spring rate of the air spring is the range of 20 to 120 inches. To achieve this range, the angle of an element of the frustro-conical surface with respect to the axis of the piston is greater than 20°, and preferably about 23°.In order to achieve the required volume for the ai spring, the interior of the piston is open to the interio of the flexible sleeve. Desirably, the volume of the piston is in excess of 100 cu. in. (1639 cu. cm) and the combined volume of the piston and sleeve is in the range of 850 to 1500 cu. in. (13,900 - 24,600 cu. cm) under design loads. Desirably, spring rates in the range of 100 to 300 pounds per inch (17.5 - 52.5 KN/m) at design loads in excess of 5,000 lbs (2268 kg) are achieved with the invention.The piston further comprises an outwardly tapered surface joining the bottom of the frustro-conical surface to provide an area of larger diameter, thereby increasing -5- the effective area of the air spring in the event that compression is significant .enough to drive the lobe past the minimum diameter of the piston. Further, a plate with an opening in the top thereof is provided at the top por- tion of the pedestal and a rubber bumper is secured at an upper portion of the sleeve to prevent compression of the sleeve past a predetermined point.Brief Description of the Drawings The invention will now be described with reference to the accompanying drawings in which:Figure 1 is a side elevational view in section of an air spring assembly according to the invention shown under normal loading conditions; Figure 2 is a view similar to Figure 1 showing the air spring under jounce condition;Figure 3 is a composite graph showing the relation¬ ship between deflection and the effective area and between deflection and load at various pressures.Best Mode for Carrying Out the InventionReferring now to the drawings, and to Figure 1 in particular, there is shown an air spring assembly 12 secured at an upper portion to a vehicle frame 14 and at a lower portion to a vehicle axle assembly or trailing arm 16. The air spring assembly comprises a rubber flexible sleeve 18 secured at an upper portion thereof to an upper retainer 20 and bumper 22 and at a lower portion to a piston member 32. Bolts 24 and 26 secure the air spring assembly through the upper retainer 20 to the vehicle frame 14.The rubber flexible sleeve is tubular shaped and is constructed from laminated rubberized fabric having inextensible cords crossed with respect to each other in the manner described in the U.S. patent to Hirtreiter, 3,043,582 (issued July 10, 1962). The inextensible elements are positioned at an angle of about 30° with respect to the axis of the tubular flexible sleeve 18 -6- in unexpanded condition such that, upon expansion of the flexible sleeve 18, the angle between the cords and the axis of the flexible sleeve expands to about 54°. In • this condition, the flexible sleeve 18 achieves its maximu diameter. The sleeve 18, itself, is conventional and sleeves of this nature are commercially available from Goodyear Tire & Rubber Co.At an upper portion, the rubber flexible sleeve 18 has an annular wire ring 28 through which it is secured to the retainer 20. In like manner, a lower wire ring 30 at the lower portion of the flexible sleeve 18 is provided for securing the sleeve 18 to the piston 32 between a reservoir can 34 and the piston 32. As illustrated in Figure 1, the upper wire ring 28 has a greater diameter than the lower wire ring 30. The reservoir can 34 is secured to the axle 16 through a bolt 36 and provides a sealed interior chamber for the piston 32. A sealing compound or sealing washer (not shown) is provided for bolt 36 to maintain the reservoir can 34 air tight. A retainer plate 38 having an opening 40 is secured to the top of the reservoir can 34 through welding or other suit¬ able fasteners to provide an abutment surface for bumper 22 under very high jounce conditions.The piston 32 has a shape which is very important to the operating characteristics of the air spring assembly.. It has an outwardly extending top portion 42 having a relatively large radius, downwardly curved surface 43 which smoothly joins an inverted frustro- conical surface 44. An outwardly extending lower portion 48 joins the inwardly directed surface 44 at a minimum diametrical area 46. As seen in Figure 1, the diameter of area 46 is greater than that of the lower ring 30 but significantly less than that of the outer portion of surface 43. The outer surfaces of the piston 32 are smooth and circular in any horizontal section taken therethrough. The piston is conveniently cast from any suitable cast- able material and the outer surface can be machined s ooth, if desirable. The casting is desirably hollow, having an interior surface 50 shown in phantom lines in Figures 1 and 2, and has strengthening ribs 52 spaced at appropriate locations within the casting. The operation of the air spring under jounce, i.e. when the vehicle hits a bump, is illustrated in Figure 2. The lower portion of the flexible member 18 will roll along the surface 44, thereby decreasing slightly the effective area within the spring. In addition, the piston is dimensioned so that the spring rate is sub¬ stantially flat, i.e. in the range of 100 - 300 lbs/in. (17.5 - 52.5 KN/m) during the roll of the flexible member along the surface 44. However, when the flexible member 18 reaches the minimum diametrical, area 46, the effective area of the spring will increase rather quickly, thereby increasing the spring rate to stop the jounce before the spring bottoms out on the bumper 22.The angle of surface 44 with respect to the axis of the piston is quite important with respect to the opera- tion of the spring. This angle is measured by taking a section through the central axis of the piston 32 which is shown as phantom line 54 in Figure 1. The central axis 54 is perpendicular to the base of piston 32. The inter¬ section of the plane taken through the central axis 54 with the surface 44 forms an element of surface 44. An extension of an element is shown as phantom line 56 in Fig. 1. Thus, the angle between the surface 44 and the axis of the piston 32 is measured between phantom lines 54 and 56. Desirably, this angle is greater than 20°, preferably about 23°, but not more than 30°.The diameter of the piston with respect to the air spring is also of some considerable significance. The piston diameter must be small enough to permit rolling of the lobe on the relatively large return angle frustro- conical surface 44 without collapsing of the lobe.Typically, for a 13-in. (35.4 cm) diameter air spring, the diametrical difference between the air spring ID and the piston OD must be at least 3 in. (7.6 cm) andT RE__0MPI_ ' -8- preferably about 3.4 in. (8,6 cm). Diametrical differ¬ ences would be slightly greater for larger air springs and slightly smaller for smaller air springs.An air spring according to the invention was constructed with the following approximate dimensions: Sleeve - Goodyear sleeve part No. AS4-26-3-017Max. diam. 336.6 mm (13.25 in.) PistonHeight - 132.0 mm (5.20 in.) Maximum diameter atCurved surface 43 - 244.0 mm (9.61 in.) Radius of curved surface - 27.0 mm (1.06 in Height of area 46 - 33.0 mm (1.30 in.) Radius of surface - 24.0 mm (0.94 in.)Volume at area 46 - 1968 cm3 (120 in.3) Air spring assemblyDesign height - 304.8 mm (12 in.) Diam. of sleeve 18 - 336.6 mm (13.25 in.) Volume - 13880 cm3 (970 in.3)The effect of jounce in terms of effective area an deflection for the air spring of the example is illus¬ trated in Figure 3 to which reference is now made. At the upper portion of Figure 3 there is shown the rela- tionship between the effective area of the air spring sleeve and deflection in inches with 12 inches being the design height. Under jounce, the effective area actually decreases for about 2 inches and then increases significantly. At rebound, the effective area increases to dampen the oscillation of the air spring.In the lower portion of Figure 3 there are illus¬ trated curves showing the relationship between load on the air spring and deflection. At the design height, the spring rate is positive but only slightly so compared with the spring rate at higher jounce deflections. Note that the spring rate around the design height is rela¬ tively constant regardless of the degree to which the spring is loaded.0Λ1P The following data was obtained from tests on an air spring according to the invention:Spring Spring rate Load/Pressure at design height FN spring rate30 psi (207K PA) 200 lb/in (35KN/M) 66 CPM 7.5 in(183 mm) 50 psi (245 KPA) 240 lb/iri (42 KN/M) 50 CPM 14.1 in(344 mm)70 psi (43 KPA) 260 lb/in (45.5 KN/M) 43 CPM 19.2 in(468 mm) 90 psi (621 KPA) 130 lb/in (22.8 KN/M) 26 CPM 51 in(1243 mm)In an air spring constructed according to the invention, the reservoir 34 is significant in maintaining a relatively constant volume under jounce conditions.Desirably, the reservoir has a capacity in excess of 1003 cu. in. (1639 cm ) and preferably about 120 cu. in.(1965 cu. cm) . The total volume of the air spring including the reservoir is preferably in the range of 850 cu. in. (1390 cu cm) .to 1500 cu. in. (2460 cu. cm), desirably at about 1000 cu. in. (16,390 cu. cm) . Thus, the reservoir adds significant volume to the air spring to assist in reaching the relatively small spring rate and the relatively large load to spring rate ratios. The air spring according to the invention provides a ride that is very smooth over rough roads so that very little shock is transmitted to the vehicle frame when the vehicle hits a bump. The .invention is particularly adapted to heavy loads such as carried by vehicles in the trucking industry. The smooth ride is the result of a low spring rate at design height. This spring rate has not been heretofore achievable in other designs at the higher loads.Reasonable variation and modification are possible within the scope of the foregoing disclosure and drawings without departing from the spirit of the invention which is defined in the accompanying claims._0 j Wipo- | -10-~CLAIMS1. In an air spring of the rolling lobe type wherein a hollow elastic sleeve is restrained from expanding past a predetermined diameter at a design load; wherein means are provided for securing an upper end of the sleeve to a vehicle frame; a hollow piston adapted to be secured to a vehicle axle mounts a lower end of the sleeve and provides an outer surface on which the lower end of the sleeve rolls in jounce and rebound; means are provided for securing the sleeve to an upper portion of the piston; and means provide an open communi cation between the interior of the hollow sleeve and the interior of the hollow piston whereby the interior of th piston provides a reservoir for the air spring; the improvement which comprises: the exterior surface of the piston providing an outwardly extending top surface joining a relative large radius downwardly curved surface on which the lobe of the hollow sleeve rests during normal loading and an inverted frustro-conical surface extending downwardly from the downwardly curved surface and providing an area of increasing reduced diameter for the rolling lobe of the hollow sleeve during jounce, the angle of the frustro-conical surface and the volume of the piston and sleeve being such that the spring rate is in the range of 100 - 300 lbs/in. (17.5 KN/m - 52.5 KN/m) at loads above 5,000 lbs (2268 kg.) .2. An air spring according to claim 1 wherein th angle of an element of the frustro-conical surface with respect to the axis of the piston is greater than 20°.3. An air spring according to claim 2 wherein th angle of the frustro-conical surface with respect to the axis of the piston is about 23°,4. An air spring according to claim 2 and furthe -11- comprising a plate secured to an upper portion of the piston and an opening in the plate providing communication between the interior of the hollow sleeve and the interior of the piston; and a resilient bumper secured to the upper sleeve end securing means and adapted to strike the plate at extreme deflection positions of the air spring.5. An air spring according to claim 4 wherein the piston further comprises an outwardly flared surface join- ing the bottom of the frustro-conical surface and provid¬ ing an area of larger diameter to increase the effective area of the air spring and retard further deflection thereof as the rolling lobe in deflection reaches the outwardly flared surface and prior to the striking of the plate by the resilient bumper.6. An air spring according to claim 5 wherein the volume of the piston reservoir is in excess of 100 cu. in.(1639 cu. cm. ) .7. An air spring according to claim 6 wherein the volume of the interior of the piston and hollow spring under load is in the range of 850 to 1500 cu. in. (13,900 - 24,600 cu. cm. ) .8. An air spring according to claim 7 wherein the volume of the interior of the piston and hollow spring under load is about 1000 cu. in. (16,390 cu. cm.) .9. An air spring according to claim 8 wherein the piston shape, the volume of the air spring and the piston are such that the ratio of load to spring rate for the air spring is about 20 in. (50.8 cm.) for loads in excess of 5,000 lbs (2268 kg.) .10. An air spring according to claim 1 wherein the volume of the piston reservoir is in excess of 100 cu. in. (1639 cu. cm.) . 11. An air spring according to claim 10 wherein the volume of the interior of the piston and hollow sleev under load is in the range of 850 to 1500 cu. in. (13,900- 24,600 cu. cm.) .12. An air spring according to claim 1 wherein th piston further comprises an outwardly flared surface ad¬ joining the bottom of the frustro-conical surface and providing an area of larger diameter to thereby increase the effective area of the sleeve and retard further deflection of the air spring as the rolling lobe of the sleeve reaches the outwardly flared surface.13. An air spring according to claim 1 wherein th volume of the interior of the piston and hollow sleeve under load is in the range of 850 to 1500 cu. in. (13,900- 24 , 600 cu. cm. ) . | LEAR SIEGLER INC | PIERCE W |
WO-1979000416-A1 | 1,979,000,416 | WO | A1 | EN | 19,790,712 | 1,979 | 20,090,507 | new | F16B7 | G05G5, E21D15, F16H27 | F16B7 | F16B 7/10B | A LOCKING DEVICE FOR LOCKING TWO RELATIVE EACH OTHER MOVABLE PARTS | A locking device for locking two relative each other movable parts (1, 2) in one of their directions of motion and releasing in the opposite direction of motion, at which one of the parts (1) is provided with teeth or similar and the other part (2) supports a spring-loaded retaining member (6) cooperating with the teeth. The purpose of the invention is to provide a simple and reliable locking device. This has been achieved by the fact that the retaining member (6) is freely swingably mounted and that the teeth-provided (3) part (1) is designed with at least two spaces of tooth (8), one at each end of the toothed path, with a depth exceeding the radial length of the retaining member (6), said spaces of tooth serving as turning stations for the retaining member. | A LOCKING -DEVICE FOR LOCKING TWO RELATIVE EACH OTHER QVEABLE PARTSBackground of the inventionThe present invention refers to a locking device for locking two relative each other moveable parts in one of their directions of motion and releasing in the opposite direction of motion, one of the parts being provided with teeth or similar and the other part supporting a spring-loaded retaining member coopera¬ ting with the teeth.Locking devices of the above mentioned kind are re¬ quired for many purposes, but thev have hitherto been relatively complicated or not completely reliable.Summare of the inventionThe purpose of the present invention is to provide a locking device which is characterized bv its simple construction and its reliable operation. This has been achieved by the fact that the retaining member is freely swingablv mounted and that the teeth-provided part is designed with at least two spaces of tooth, one at each end of the toothed path, with a depth exceeding the radial length of the retaining member, said spaces of tooth serving as turning stations for the retaining member.Brief description of the drawingsThe invention will now be further described with refe¬ rence to the accompanying drawings , which show some embodiments.: *r j. BAO Figure 1 is a side view of a locking device accordi to the invention applied to telescopic tubes, Figure 2 shows on a larger scale a section accordin to the line II - II in figure 1, 5 Figure 3 is a longitudinal section through the lock device according to figure 2,Figure is a longitudinal section through a modifi embodiment of the invention with the locking device placed within one of the telescopic tubes,10 Figure 5 is a section analogue with figure k but wi the locking device in turning position, Figure 6 is a section through a locking device appl to a device with an arc-shaped toothed path, Figure 7 shows the device according to figure 6 in15 a position for turning the retaining member, andFigure 8 is a section through a further embodiment of the invention.Description of some Dreferred embodiments20The locking device according to the invention compr two relative each other moveable parts 1 and 2, the first part 1 of which being provided with teeth 3 o similar along one side edge, while the second part 25 2 is provided with a locking device h comprising a retaining member 6 . which is freely swingably mount about an axle 5 and which by a spring 7 is brought to engage the teeth 3 of the first part 1.30 In the embodiment shown in the figures 1-3 the part 1 and 2 comprise two telescopic rods or tubes, at which the teeth-provided rod 1 is displaceable in the tube 2. The rack 1 is at each end of the toothe path 3 provided with a space of tooth 8 with a dept35 exceeding the radial length of the retaining memberBADORiatNAt/ _O y VVI 6, so that i*he retaining member in cooperation with said space of tooth 8 can be brought to turn. In such cases where several turnings are desired spaces of tooth can be arranged also between the end turning stations 8. In the embodiment shown the axle 5 is supported by a loop 9, which is fixed to the outer telescopic tube 2 and is situated just in front of a recess 10 in said tube. 'In the embodiment according to the figures and 5 the outer telescopic tube 2 is along one edge side provided with inwards directed teeth 3 cooperating v/ith the locking device . which is arranged at the inner tube 1. The inner tube 1 has a U-shaped cross- section and is so arranged in the outer tube 2 that the teeth 3 are located between the shanks 11 of the inner tube 1. In the shanks 11 recesses for the axle 5 are arranged, said axle serving as a pivot for the freely swingable retaining member 6 in the same way as in the embodiment described above. The retaining member 6 is pressed against the teeth-provided inside of the outer tube 2 by means of the spring 7, which is so arranged that v/hen the retaining member 6 is located in a space of tooth 8, as is shown in figure 5, the retaining member 6 will take a position between its two end positions. The spring 7 is preferably held by a clip 12 at the retaining member 6 and a clip 13 at the middle portion I k of the U-shaped inner member 1.The devices according to the figures 1-5 work in the following wav . In one position, e.g. when the inner rod 1 is drawn out of the outer tube 2 the retaining member 6 will against the action of the spring 7 snap over the teeth 3 at the same time as the retaining member prevents the inner rod from being pushed back- wards. When *he retaining member 6 is in front of a space of tooth 8, the retaining member can be swung so much that it changes position and the inner rod 1 can be pushed back without the retaining member 6 offering any appreciable resistance. At the opposite end position the retaining member 6 will again snap into a space of tooth 8, so that the retaining member is turned back to its first starting position.In the embodiment according to the figures 6 and 7 the toothed path of one of the parts 1 is arc-shaped, while the other part 2 is pivotallv mounted in the centre of the arc-shaped toothed path about a pivot pin 15. The retaining member 6 of the locking device ■■ is in the same way as above freely swingably mounted about an axle 5. At both end portions of the toothed path 3 a deeper notch or a space of tooth with a large depth than the length of the retaining member 6 is arranged. The device works in the same wav as the earlier described embodiments. In this embodiment e.g. one part 1 can be moveable, while the second part 2 is fixed at a structural part.In the embodiment according to figure 8 the toothed path is arranged at the fixed part 2, while the moveabl part 1 supports the locking device k .The embodiments which have been shown and described are only to be regarded as examples and a number of modifications are possible v/ithin the scope of the claims. Thus the retaining member can have a different design as well as the spring 7, which also can be placed in a different way than is shown in the drawings.O VI | C L A I S1. A locking device for locking two relative each other moveable parts in one of their directions of motion and releasing in the opposite direction of motion, one of the parts being provided with teeth or similar and the other part supporting a spring- loaded retaining member cooperating v/ith the teeth, c h a r a c t e r i z e d i n, that the retaining member (6) is freely swingably mounted and that the teeth-provided (3) part (1) is designed with at least two spaces of tooth (8), one at each end of the toothed path, with a depth exceeding the radial length of the retaining member (β), said spaces of tooth serving as turning stations for the retaining member.2. A locking device according to claim 1, c h a ¬ • r a c t e r i z e d i n, that the spring (7) of the retaining member (6) is arranged to keep the retaining member in a position between its two end positions in the unaffected position of the retaining member.3. -A. locking device according to claim 1 or 2, c h a ¬ r a c t e r i z e d i n, that the teeth-provided (3) part (1) is provided with one or several spaces of tooth between the end position spaces of tooth.*J. A locking device according to any of the preceding claims, c h a r a c t e r i z e d i n, that the parts (1, 2) consist of telescopic rods or tubes.5. A locking device according to any of the preceding claims, c h a r a c t e r i z e d i n, that one of the parts (1 and 2 resp. ) comprises an arc-shaped toothed path, while the second member is ivotallv mounted in the centre of the arc-shaped toothed path.BADQBJGiNAt | AKSELSEN O; OTTAR INNOVATION HANDELSBOLAG; OTTAR INNOVATIONER HANDELSBOLAG | AKSELSEN O |
WO-1979000428-A1 | 1,979,000,428 | WO | A1 | XX | 19,790,712 | 1,979 | 20,090,507 | new | H02J5 | null | C25D5, H02J1, H02M7, H02P13 | C25D 5/18, H02P 13/06 | SUPPLIER OF DIRECT CURRENT WITH SUPERIMPOSED ALTERNATING CURRENT | A power supply and a method for providing in a convenient and inexpensive way an unlimited range of directs currents with superimposed alternating sinusoidal or non-sinusoidal currents to a single load or to a number of loads in parallel. A novel power supply derived from a conventional one by purposely unbalancing AC potentials of load terminals so that an additional AC voltage drop appears across the load. This unbalancing is accomplished through changing AC potentials of one or both load terminals (48, 49) by connecting one of the terminals to different points along a special unbalancing transformer winding (40) and/or by connecting a capacitor (50) between a load terminal (48) and different points of this unbalancing winding. | SUPPLIER OF DIRECT CURRENT WITH SUPERIMPOSED ALTERNATING CURRENTTECHNICAL FIELDThis invention relates to supplying of electrical energy and particularly to supplying an unlimited range of direct currents with superimposed sinusoidal and non- sinusoidal alternating currents.BACKGROUND ART There are a number of methods for providing direct current (DC) with a superimposed alternating current (AC). In each of these methods it is necessary to provide isola¬ tion between the DC and AC sources. A typical method of such decoupling is illustrated by a diagram in Fig. 1. An inductance 3 blocks the flow of alternating current into a DC source 1 while a capacitor 4 prevents an AC source 2 from short circuiting the DC power supply. A power supply of this type which provides an AC current superimposed on DC current to a load 5, however, becomes unwieldy in applications where large currents (of the order of thousands of amperes) are required as in the case of some electrochemical installa- tions. In such. cases the values of inductance 3 and capaci¬ tance 4 become quite large and proh biti ely expensive,A method that provides a partial solution to these problems is illustrated by a diagram in Fig. 2. Alternating current is provided by a transformer 11 with a center tap 12. A DC power source 13 is connected between the center tap 12 on the transformer and the common point 14 of two loads 15 and 16. If the loads are identical, then AC voltage across the DC supply 13 is zero and no inductance is required to prevent the alternating current from flowing through the DC source. Also no capacitor is required in this circuit. The main disadvantage of this approach is the requirement that the two loads be identical. The need for balanced loads creates a number of difficulties in practica applications and has the effect of increasing the cost of industrial.processes which require the use of such supplies.DISCLOSURE OF INVENTIONIn brief, the present invention overcomes most of the problems encountered in the existing methods for supply ing direct current with a superimposed alternating current. The new power supply does not use blocking inductive ele¬ ments, requires no blocking capacitors and can work with single loads. For these reasons the supply provides a con- venient and inexpensive method and system of generating an almost unlimited range of currents from very small to ex¬ tremely large values.In all conventional rectifier circuits one end of a load (which will be referred to henceforth as the first load terminal) is essentially connected to a rectifier cir¬ cuit element or to a common point of several such elements. The other end of the load (which will be referred to hence¬ forth as the second load terminal) is connected to a trans¬ former winding or to another rectifier circuit element or to another common point of several such elements. In the case where a filter capacitor is connected across the load, the filter capacitor terminal which is connected to the first load terminal is designated the first capacitor__0ΛJ 3 terminal , and the capacitor terminal connected to the second load terminal is designated the second capacitor terminal. A conventional rectifier circuit is designed to have AC potential difference between the first and second load terminals equal or nearly equal to zero. We will consider this case as one when AC potentials of the load terminals are balanced. In a full-wave center tapped rectifier, for example, balancing is achieved by connecting the second load terminal and the second capacitor terminal to the center tap of the transformer.According to the invention, superposition of AC voltage on DC voltage is obtained through purposely unbal- ancing AC potentials of the load terminals by changing AC potential of the first load terminal and/or of the second load terminal so that an additional difference between these potentials will appear across the load. This change in AC potentials may or may not be accompanied by a change in DC potentials of the load terminals depending on the method used for varying the AC potentials.If the second load terminal is connected to the center tap of the transformer winding, the AC potential of only this terminal may be changed, and subsequently the un- balancing will follow, by disconnecting the terminal from the center tap and connecting said terminal to other points along the winding. A transformer winding which is used for unbalancing will hereinafter be referred to as the un¬ balancing winding. The position of capacitors initially shunting the load should remain unaltered; i.e., the capaci¬ tor should remain connected between the first load terminal and the center tap of the transformer in this case. No change of DC voltage across the load will be observed here since the AC potential of the first load terminal remains unchanged.A change in AC potential of only the first load terminal may be accomplished by connecting one or more coupling capacitors between the first load terminal and different points along the unbalancing winding. These capacitors may initially shunt the load or they may be specially added to change the potential of the first load terminal. Since the AC potential of the first load ter¬ minal changes, the AC voltage across the rectifier elements also changes. This process in turn alters the magnitude of the rectified DC voltage.The same method may be used to change the AC potential of the second load terminal when this terminal is connected to a common point of several (at least one) rectifier circuit elements. It is understood that AC and DC potentials of both load terminals may be changed simultan¬ eously to obtain the desired value of AC and DC voltages across the load.If the input voltage of the new power supply is sinusoidal and capacitors used in the circuit are big enough, the waveform of the AC component across the load is sinusoi¬ dal too. This waveform will vary, depending on the waveform of the input voltage or on the magnitude of capacitors used. Also, the waveform of the AC component may be changed with the help of thyristors used as rectifier circuit elements.A non-sinusoidal AC waveform may also be acquired even when the capacitors in the circuit are big enough and normally provide sinusoidal waveform. The non-sinusoidal waveform in this case is formed by introducing another non¬ linear element into the circuit (the first non-linear element being diodes or thyristors). This non-linear circuit ele¬ ment may be, for example, a saturable core reactor used for voltage control in the primary of the transformer. Likewise semiconductor controlled rectifiers may be used at the input of the system for voltage control providing non-sinusoidal waveform of AC component across the load.The new method of superimposing alternating cur- rent on direct current provides an unlimited ratio of AC to DC voltage from zero to infinity.The invented method and system are valid for a rectifier circuit with an arbitrary number of rectifier cir-OΛΪPI 5 cuit elements.If the use of the invented method results in the appearance of an excessive magnetic flux in the transformer, various existing flux compensating methods can be used. These methods may include sectionalizing of the transformer windings or providing an additional compensating winding, etc.The new power supply may be considered as a source of a modulated voltage, wherein the DC voltage is a carrier and the sinusoidal or non-sinusoidal component is a modulating voltage. The voltage instead of current approach is important particularly when the load is non-linear and the voltage waveform, which may be more easily controlled, substantially differs from the current waveform.BRIEF DESCRIPTION OF DRAWINGSThe invention will be more readily understood from the following detailed description taken in conjunction with the drawings in whichFig. 1 is a diagramatic representation of an example of prior art and shows separate DC and AC supplies; Fig. 2 is a diagramatic representation of another example of prior art and shows a DC supply with a center tapped secondary transformer winding; Fig. 3 is a schematic block diagram which illus¬ trates the invented method and system for providing an AC voltage superimposed* on a DC voltage across a load; Fig. 4 is another block diagram which illustrates the invented method and system for providing an AC voltage superimposed on a DC voltage; Fig. 5 shows a circuit diagram for a DC + AC power supply based on a full wave center tapped rectifier and illustrates the invented method of unbalancing AC poten¬ tials at the load terminals; Fig. 6 is a graphic representation of different types of voltages across the load with a large capacitor 50 in the circuit of Fig. 5 connected to the center tap; Fig. 7 is a view similar to that of Fig. 6 but with no capacitor used in the circuit;Fig. 8 is a view similar to that of Fig. 6 but with the second capacitor terminal 52 connected to different points along an unbalancing winding;Fig. 9 shows a circuit diagram for a DC + AC power supply based on a halfwave rectifier circuit and illustrates the invented method of unbalancing AC potentials at the load terminals;Fig. 10 shows a circuit diagram for a DC + AC powe supply based on a fullwave rectifier and illustrates the invented method of unbalancing AC potentials at the load terminals; Fig. 11 shows a circuit diagram for a DC + AC powe supply based on a multi-phase rectifier and illustrates the invented method of unbalancing AC potentials of load termi¬ nals;Fig. 12 shows a circuit diagram of a DC + AC power supply based on a three-phase rectifier and illustrates the invented method of unbalancing AC potentials of load termi- ' 'nals.DETAILED DESCRIPTION OF THE INVENTIONThe present invention will hereinafter be describe in detail.Fig. 3 illustrates one of the principles of the invention. An AC power source 21 supplies at least a single phase sine wave voltage at frequencies up to kilohertz and more but preferably at a conventional 60Hz through a suit¬ able voltage-control device 22 such as a saturable core reactor, semiconductor control rectifiers, or an autotrans- former. If desired, the voltage-control unit may be elimin- ated where a constant voltage is needed at the output of the system. The primary 23 of a single phase or a multi-phase transformer is coupled with the voltage-control unit. The windings of the primary may be star-connected. The connec- 7 tion of windings is ordinarily preferable since it brings about a more even distribution of currents in the phases of the power supply 21. The secondary 24 of the transformer has two types of windings: ordinary and unbalancing wind¬ ings. All these windings are star-connected. An ordinary winding is used exclusively for supplying AC voltage to a system 25 of rectifier circuit, elements, whereas an un¬ balancing winding is used mainly for supplying an unbal- ancing AC voltage to terminals 27 and 28 of a load 26, though this winding may also be used for supplying voltage to the rectifier system. The first load terminal 27 is connected to a system of rectifier circuit elements 25 and the second.load terminal 28 is directly connected to the secondary of the transformer so that a DC voltage is pro¬ vided across the load. If a minimum value of AC voltage component is desired across the load, the second load terminal is connected to the point of star connection of the windings. In this case, AC potentials of the load terminals are balanced. An additional AC voltage is introduced across the load when the second load terminal is connected to dif¬ ferent points of the unbalancing winding which provides unbalancing of AC potential of the second load terminal. The AC potential of the first load terminal 27 may be also altered with the help of a coupling capacitor 29 connected to the unbalancing winding. This capacitor affects also the waveform of the AC voltage component across the load even if it doesn't change the AC potential of the first load terminal which occurs when the second capacitor ter- minal is connected to the point of star-connection of transformer windings.The schematic block diagram represented in Fig. 3 illustrates a plurality of power supplies wherein one of the load terminals (namely the second terminal) is connected directly to a transformer winding.If both load terminals are connected to different points of a system of rectifier circuit elements, another block diagram applies. This diagram is represented in Fig. 84, and the same elements as those of Fig. 3 are used here except that two coupling capacitors 39 and 40 may be em¬ ployed, one for changing AC potential of the first load terminal 37 and/or another for changing AC.potential of the second load terminal. It is understood that the value of these capacitors affects the waveform of the additional AC component across the load 36.The principles of the invention disclosed in Fig. 3 and 4 will be further illustrated by a number of pre¬ ferred embodiments. These embodiments mainly differ by circuits connected to the secondary winding of the trans¬ former.In the case of a two-phase power supply, usually known as a full-wave center tapped rectifier installation depicted in Fig. 5, a two-phase transformer secondary com¬ posed of two windings 40 and 41 with a center tap 42 is in circuit with two rectifier elements 43 and 45. These cir¬ cuit elements have a common point 46 which is a first out- put terminal of the rectifier system. Both rectifier elements have the same direction with respect to the output terminal 46 and, of course, with respect, to terminals of the transformer windings 40 and 41 to which they are con¬ nected. Under the term rectifier circuit elements we mean hereinafter diodes and/or thyristors. A load 47 is connected by its first terminal 48 to the first output ter¬ minal and by its second terminal 49 to the center tap 42 of the transformer secondary. A capacitor 50 with its first terminal 51 and a second terminal 52 is connected respec- tively to the first load terminal 48 and to the center tap 42 of the transformer. As long as the second load terminal and the second capacitor terminal are connected to the transformer center tap only, direct current with a ripple dependent on the value of the capacitor 50 will flow through the load. In this case an AC voltage component across the load is minimal and AC potentials of the load terminals may be considered as being balanced. If capaci¬ tance C of the capacitor 50 is very large (tending to infinity), a pure DC voltage with no AC component will be applied to the load (see Fig. 6a). This DC voixage is equal to a half of the amplitude A of the AC voltage across the transformer secondary which includes two windings 40 and 41.According to this invention an additional AC voltage component will be introduced across the load 47 when the second load terminal 52 is moved from the center tap and is connected to different points along either transformer winding, whereas the second capacitor terminal is still connected to the cente tap. Different posi¬ tions of the second load terminal are schematically indi¬ cated by dotted arrows. When the second load terminal moves along the winding 40, AC potential of this terminal changes and'becomes unbalanced with respect to the AC po¬ tential of the first load terminal. Thus, the transformer winding 40 is called unbalancing winding . The unbal¬ ancing winding plays a dual role here: it changes the AC potential of the second load terminal and also supplies voltage to the rectifier circuit element 43. If the second load terminal 49 is connected to an intermediate point along the unbalancing winding 40 and capacitance C of the capacitor 50 is large, and also a sine wave voltage is applied to the input of the transformer, the waveform of additional component across the load is sinusoidal too.This component has an amplitude which is intermediate be¬ tween zero and A/2, whereas the DC voltage is the same as it was initially, i.e., before moving the second load ter¬ minal (see Fig. 6b). When the second load terminal reaches the end of the unbalancing winding, the amplitude of the AC component equalizes with the DC voltage (see Fig. 6c). A dramatic change of the AC component waveform will accrue from diminishing the capacitance of the capaci¬ tor 50 provided all other conditions remain unaltered. In the extreme when the capacitor 50 is disconnected (capaci¬ tance C = 0), the waveform of the voltage across the load will be as depicted in Fig. 7a if the second load terminal is connected to the center tap. When this terminal is connected to an intermediate point along the unbalancing winding, the waveform is as in Fig. 7b, and, at last, as in Fig. 7c when the terminal reaches the end of the winding. It should be noted that the average value of the voltage appearing across the load remains constant for all positions of the load terminal and will be equal to A/τr.A similar effect would occur if winding 41 rather than winding 40 were used as the unbalancing winding. So far we have discussed the method and system for unbalancing the AC-potential of the second load termin¬ al which has the reference number 49 in Fig. 5. It is also possible to unbalance the AC potential of the first load terminal 48, -which may be accomplished by connecting the second capacitor terminal 52 to different points of either winding 40 or 41 , leaving the second load terminal 49 con¬ nected to the center tap 42.The capac tor 50 in this case w ll act as a coupling capacitor transferring different AC potentials along the unbalancing winding to the common point 46 of the rectifier circuit elements. Since the AC voltage difference across the rectifier elements changes, it causes a change of the DC voltage component. Fig. 8 illustrates this phenomenon. When both second load and second capacitor terminals are connected to the center tap 42, the DC compo¬ nent is equal to A/2 and no AC component across the load exists, provided the capacitance C is large enough (see Fig. 8a). If the second capacitor terminal 52 is con¬ nected to an intermediate point of the unbalancing winding and the load terminal 49 remains connected to the center tap 42, the DC voltage increases and a sinusoidal component appears across the load. In the extreme, when the second capacitor terminal reaches the end of the unbalancing wind¬ ing, the DC component is equal to A and the amplitude of the AC component is equal to A/2 (see Fig. 8b).It is also possible to unbalance the AC poten¬ tials of both load terminals si ultaneously by moving the second load and the second capacitor terminals along one or BUR £O PI two unbalancing windings. An additional AC voltage com¬ ponent will appear across the load, provided the second load and capacitor terminals are not connected to the same point. In the extreme, when these terminals are connected to the opposite ends of the windings 40 and 41 , the DC voltage is equal to A and the amplitude of the AC voltage component is also equal to A (see Fig. 8c). The connection of the second capacitor terminal to different points of the winding is schematically shown in Fig. 5 by dotted arrows .It should be noted that none of the described waveforms reverse the polarity of the potential across the load, a situation which may be essential for many electro- chemical and other applications of the invented AC + DC power supply.A half-wave recti fier -circuit and a method repre¬ sented in Fig. 9 form a special case because in th s circuit the sinusoidal AC component may exceed the DC component across load 65. It will happen only if the AC potential of the first load terminal 66 is unbalanced, which may be accomplished by connecting second capacitor terminal 70 to different points of unbalancing winding 61 , leaving the second load terminal 67 connected to end 62 of the winding. The coupling capacitor 68 will transfer an AC voltage to the first load terminal 65, reducing the AC voltage drop across rectifier circuit element 64, thus resulting in diminishing the DC voltage rectified by this element. When the second load terminal reaches the end 63 of the unbalancing winding, the DC voltage across the load reduces to zero and the ratio of AC to DC components is equal to infinity.No change of the DC component will happen if the AC potential of the second load terminal 67 is unbalanced by moving this terminal along the unbalancing winding 61 while the capacitor 68 remains connected to the rectifier circuit element 64 with the first capacitor terminal 69 and remains connected to the end 62 of the winding 61 with the second capacitor terminal 70. In this case the value of only the AC component will change. The amplitude of this- - component reaches A when the second load terminal is con¬ nected to the end 63 of the unbalancing winding. The wave¬ form of the voltage across the load 65 in this case is ade- quate to that of Fig. 8c which referred to the full-wave center-tapped system as depicted in Fig. 5. Moreover these two diagrams provide identical AC + DC voltages across the load not only in the previously discussed case. Identical voltages will also appear if in the circuit of Fig. 9 the second load terminal 67 is connected to the center point 71 of the winding 61 and the second capacitor terminal 70 moves along this winding in the direction of its end 62. The iden¬ tity of the voltages will also occur in the opposite situa¬ tion when the second capacitor terminal 70 remains connected to the point 71 and the load terminal 67 would move to the end 62.It means that a half-wave system of Fig. 9 may be represented in the majority of cases by a full-wave center- tapped system of Fig. 5 with one of two rectifier elements disconnected. Suppose the circuit element 45 is discon¬ nected; then the ordinary phase winding 40 is used exclu¬ sively for rectification whereas the second phase winding 41 is used exclusively for unbalancing. The idea of pro¬ viding a special winding which is used exclusively for un- balancing is very beneficial for multi-phase systems, as will be discussed below.In systems of Fig. 5 and Fig. 9 the second load terminal is connected directly to the transformer winding in compliance with the principle disclosed in Fig. 3, where- as the first load terminal is connected to at least one rectifier circuit element. According to the principle dis¬ closed in Fig. 4, the second load terminal may also be con¬ nected to at least one rectifier circuit element which is different from the element connected to the first load terminal. This may happen, for instance, in a system which is based on a full-wave rectifier bridge represented in Fig. 10. Four rectifier circuit elements 74, 75, 76 and 77 forming a bridge rectifier circuit are connected to one-■^UR£4 phase transformer secondary 71. Two of these elements, viz. 74 and 75, constitute a first group having a common -point 78 which is a first output terminal of the rectifier system. Both these elements have the same direction with respect to this output terminal. A second group includes elements 76 and 77 having a common point .79 which is a second output terminal of the rectifier system. The elements of the second group have the same direction with respect to the second output terminal but this direction is opposite from that of the elements of the first group. Therefore, DC potentials of the first and second output terminals are of opposite polarity. A load 80 is connected with its first terminal 81, to the first output terminal and with its second terminal 82. to the second output terminal. AC po¬ tentials of load termianls are in this case balanced and an AC ripple voltage across the load is minimal. The un¬ balancing of AC potential of the first load terminal is accomplished with the help of a first coupling capacitor 83 connected to the first load terminal 81 with a first capacitor terminal 84 and connected to any point of the unbalancing winding 71 with a second capacitor terminal 85. The same method may be used to unbalance AC potential of the second load terminal. A second coupling capacitor 86 is used respectively for this unbalancing with its first terminal 87 connected to the second load terminal and a second capacitor terminal 88 connected to any point of the unbalancing winding albeit different•f om the point of con¬ nection of the terminal 85. A multi-phase embodiment of the present invention is illustrated in Fig. 11. A secondary of the multi-phase transformer is formed by six star-connected windings with reference numbers from 91 to 96. Four of these windings, namely 93, 94, 95 and 96 , are ordinary windings which are used exclusively to supply voltage to rectifier circuit elements 99, 100, 101 and 102 which have a common point 103, this point constituting the first output terminal. The remaining two windings 91 and 92 are unbalancing windings and each of them plays a dual role: it unbalances AC po¬ tential of one of the load terminals and also supplies voltage to a rectifier circuit element which is 98 for the winding 91 and 110 for the winding 92. A load 104 is con¬ nected to the first output terminal 103 with a first load terminal 105. A second load terminal 106 is connected directly to any point of the unbalancing winding 92, thus introducing an additional AC voltage component across the load. Evidently, no additional voltage will be introduced if the second load terminal is connected to a point 97 of star connection of the windings. The unbalancing of AC potential of the first load terminal 105 is accomplished in the manner described in previous embodiments: a couplin capacitor 107 is used, this capacitor being connected to th first load terminal with a first capacitor terminal 108 and to the unbalancing winding 91 with its second terminal 109. It should be pointed out that the use of a special unbal¬ ancing winding 91 for changing AC potential of the first load terminal is gratuitous. In this case the same unbal¬ ancing winding 92 which is employed for changing AC poten¬ tial of the second load terminal may be used. It is eviden that if the second capacitor terminal 109 is connected to the point 97 of star connection of the windings, no unbal- ancing of the first load terminal will occur. But the role of the capacitor 107 is still important here since it essen tially affects the waveform of the AC component across the load, this component being introduced by connecting the second load terminal 106 to different points along the unbalancing winding. If the windings of the transformer secondary provide sine form voltage and the capacitor 107 i large enough, ie.e,, it has a large capacitance C, the wave¬ form of the AC component across the load is sinusoidal too. Being connected to the point 97 of star-connection, the coupling capacitor 107 becomes a wave shape forming only.As such, it has a minimal AC voltage drop and gives the ad¬ vantage of employing the least expensive electrolytic type capacitors which cannot be otherwise employed as coupling capacitors when a substantial AC voltage is applied across their terminals.It is not crucial for the unbalancing winding to supply a voltage for a rectifying system along with supply- ing the unbalancing voltage. The last function of the wind¬ ing may be the only one. In this case the rectifier circuit element 110, which is shown by dotted lines in Fig. 11, is disconnected.Another preferred embodiment of the present inven- tion, which is depicted in Fig. 12, is a particular case of the just now described multi-phase system. It is a three- phase system where a sine form voltage of industrial fre¬ quency, predominantly of 60 or 50 cycles per second, is applied from a source 110 to a transformer primary through a voltage-control system which here is a saturable core reactor with three windings 111, 112, and 113.The three-phase transformer primary consists of threeΔ -connected windings 114, 115 and 116. The Δ-connec- tion is preferable since the source appears to be more evenly current loaded therein. Still, a Y-connection may also be employed here. A saturable core reactor is purpose¬ ly chosen in this system for voltage control to provide the following two additional functions: it assists in equaliz¬ ing line currents and also changes the sine form voltage at the input into non-sinusoidal waveform at the output of the reactor to secure a non-sinusoidal waveform of voltage .component across a load. This waveform is very important in some applications, for instance when the load is an aluminum anodizing installation. Of course, other types of voltage control, such as an autotransformer or semi¬ conductor control rectifiers, may be used too. An auto¬ transformer would not change the waveform of the controlled voltage, whereas semiconductor control rectifiers do change this waveform but would not provide the same equalizing effect for the line currents as the saturable core reactor does. Three phase windings of the transformer secondary, namely 117, 118 and 119, are star connected in a point 120. Windings 118 and 119 are ordinary windings and are used BUR£4^ OMPr exclusively for supplying voltage to rectifier circuit elements 121 and 122, both elements being connected to a common point 123 and having the same direction with respect to this point. The winding 117 is an unbalancing winding and is used here exclusively for supplying voltage to change AC potential of a second terminal 125 of a load 124 which is connected to the first output terminal 123 with its first terminal 126. The unbalancing of the second load terminal is accomplished by connecting this terminal to different points of the unbalancing winding 117 which is indicated schematically in Fig. 12 by several dotted arrows. A capacitor 127 is connected to the first load terminal with a first capacitor terminal 129 and to the point of star connection 120 with the second capacitor terminal 128. An electrolytic capacitor or a plurality of capacitors con¬ nected in parallel may be used as a capacitor 127. The higher the capacitance of this' capacitor, the closer to a sinusoid will be the waveform of AC component across the load, provided the sine voltage is applied to the secondary windings of the transformer. Disconnecting the capacitor or diminishing its value would greatly affect the waveform of the AC component unless the load itself has capacitive,- reaction and the capacitance of the load is high enough. The last two embodiments of Fig. 11 and Fig. 12 represent a multi-phase system implemented in compliance with principles of the block diagram in Fig. 3, where one of the load terminals is directly connected to a winding o-f the transformer secondary and the other load terminal is connected to at least one rectifier circuit element. A multi-phase bridge rectifier system known to the skilled in the art may also be employed for a DC + AC power supply. In this system both load terminals are connected to dif- ferent groups of rectifier circuit elements according to principles of the block diagram in Fig. 4, and AC poten¬ tials of load terminals are altered in this case with the help of coupling capacitors. A Δ*-connection instead of a_OMpj Y-connection of windings of the transformer secondary may be used in this system.Although certain embodiments of the invention have been shown in the drawings and described in the specification, it is to be understood that the invention is not limited thereto, is capable of modification, and can be arranged without departing from the spirit and scope of the invention. | 1. A DC + AC power supply comprising:(a) a transformer having at least two star-connected phase windings in the secondary, at least one of these windings being an ordinary winding used exclusively for supplying an AC voltage to a rectifier system, and at least one of these windings being an unbalancing winding used for supolying AC voltage component across a load;(b) a rectifier system having at least two rectifier circuit elements, each circuit element having two ter¬ minals, one terminal being connected to any phase- winding of the secondary of the transformer, the other terminal being connected to a first output terminal, all rectifier circuit elements having the same direction with respect to said first output terminal, whereby each of the phase-windings is connected to a corresponding rectifier circuit element;(c) a load having a first and a second terminal, the first load terminal being connected to the first output terminal, and the second load terminal being connected to any point of the unbalancing winding, said point being different from the point of star connection of trans- former windings, whereby an additional AC voltage com¬ ponent is introduced across the load, said AC voltage being superimposed on a DC voltage across said load.2. A DC + AC power supply of Claim 1 further comprising(d). at least one capacitor, each capacitor having a first and a second terminal, the first capacitor ter¬ minal being connected to the first load terminal and the second capacitor terminal being connected to the point of star connection of transformer windings, said capacitor being used for changing a waveform of the AC voltage component across the load.'BU R £4 3. A DC + AC power supply of Claim.2 further comprising:(e) means for voltage control coupled with a primary of the transformer, said means including a saturable core reactor.4. A DC + AC power supply comprising:(a) a. transformer having at least three star connected phase-windings in the secondary, at least two of these windings being ordinary windings used exclusively for supplying an AC voltage to a rectifier system, and at least one of these windings being an unbalancing winding used for conducting a DC current to a load and also-for providing an additional AC voltage com¬ ponent across the load;(b) a rectifier system, having at least two rectifier circuit elements, each circuit element having two ter¬ minals, one terminal being connected to any ordinary phase-winding of the secondary of the transformer, the other- terminal being connected to a first output ter¬ minal, all rectifier circuit elements having the same direction with respect to said first output terminal, whereby each of the phase-windings except unbalancing winding is connected to a corresponding rectifier circuit element;(c) a load having a first and a second terminal, the first load terminal being connected to the first output terminal, and the second load terminal being connected to any point of the unbalancing winding, said point being different from the point of star connection of the transformer windings, whereby an additional AC voltage component is introduced across the load.5. A DC + AC power supply of Claim 4 further comprising (.d) at least one capacitor, each capacitor having a first and a second terminal, the first capacitor ter¬ minal being connected to. the first load terminal, and the second capacitor terminal being connected to the point of star connection of transformer windings, said capacitor being used for changing the waveform of the AC voltage component across the load.6. A DC + AC power supply of Claim 5 further comprising:Ce) means for voltage control coupled with a primary of the transformer, said means including a saturable core reactor.7. A DC + AC power supply comprising:(a) a transformer with at least one phase-winding in the secondary, each phase winding being an unbalancing winding used for supplying AC voltage to a rectifier system and also for providing an additional AC voltage component across a load;(b) a rectifier system having at least two rectifier circuit elements, each circuit element having two ter- minals, one terminal being connected to any unbalancing phase-winding of the transformer, the other terminal being connected to a first output terminal, said two rectifier circuit elements having the same direction in respect to said first output terminal, whereby each of the unbalancing windings is connected to a corresponding rectifier circuit element;(c) a load having a first and a second terminal, the first load terminal being connected to the first output terminal, and the second load terminal being connected to any point of any unbalancing winding, whereby an additional AC voltage component is introduced across the load;(d) at least one capacitor, each capacitor having a first and a second terminal, the first capacitor ter¬ minal being connected to the first load terminal, and the second capacitor terminal being connected to any point of any unbalancing winding, except the point to which the second load terminal is connected, whereby an additional AC voltage component is introduced acrossO m , the load.8. A DC + AC power supply comprising:(a) a transformer with one phase-winding in the secondary, said winding being an unbalancing winding used for supplying AC voltage to a rectifier system and also for providing an additional AC voltage com¬ ponent across a load;(b) a rectifier system, having at least one recti¬ fier circuit element, each circuit element having two terminals, one terminal being connected to the.un¬ balancing phase-winding of the transformer, the other terminal being connected to a first output terminal, all rectifier circuit elements having the same direc¬ tion,in respect to said first output terminal;(c) a load having a first and a second terminal, the first load terminal being connected to the first output terminal, and the second load terminal being connected ■έo any point of the unbalancing winding;(d) at least one capacitor, each capacitor having a first and a second terminal, the first capacitor ter¬ minal being connected to the first load terminal, and the second capacitor terminal being connected to any point of the unbalancing winding, except the point to which the second load terminal is connected, whereby an additional AC voltage component is introduced across the load.9. A DC + AC power supply comprising;(a) , a transformer with at least one phase-winding in the secondary, each phase-t-winding being an unbalancing winding used for supplying AC voltage to a rectifier system and also for providing an additional AC voltage component across a load;BUR£4^> (b) a rectifier system, having two groups of recti¬ fier circuit elements, the first; group consisting of at least one rectifier circuit element, each circuit element having two terminals, one terminal being con- nected to any unbalancing winding, the other terminal being connected to a first output terminal, all recti¬ fier circuit elements of this group having the same direction in respect to the terminals of the windings to which they are connected, the second group consisting of at least two rectifier circuit elements, each cir¬ cuit element having two terminals, one of said terminals being connected to any unbalancing winding, the other terminal being connected to a second output terminal, so that each end terminal of the transformer windings is connected to a corresponding rectifier circuit ele¬ ment of the second group, all rectifier circuit ele¬ ments of the second group having the same direction in respect to the terminals of the windings to which they are connected, the direction of rectifier circuit ele- ents of the second group being opposite from the di¬ rection of the first group circuit elements, whereby DC potentials of opposite polarity are provided to the first and second output terminals respectively;(c) a load having a first and a second terminal, the first load terminal being connected to the first output terminal, the second load terminal being connected to the second output terminal;(d) at least one first capacitor, each capacitor having a first and a second terminal, the first capaci- •tor being connected to the first load terminal, and the second capacitor terminal being connected to any point of any unbalancing transformer winding, whereby an additional AC component is introduced across the load.O PIWΪPC 10. A DC + AC power supply of Claim 9 further comprising: Ce) at least one second capacitor, each capacitor having a first and a second terminal, the first capaci¬ tor terminal being connected to the second load ter- minal, and the second capacitor terminal being con¬ nected to any point of any unbalancing transformer winding except the point to which the second capaci¬ tor terminal of the first capacitors is connected, whereby an additional AC component is introduced across the load.ll.. A method for providing an AC voltage superimposed on a DC voltage, the method comprising the steps of:(a) supplying an at least one-phase voltage to a modifying transformer with star-connected phase windings in the secondary;(b) modifying said AC voltage into a first and a second voltage with the help of said transformer, the first voltage being an at least one-phase voltage and being created with the help of at least one ordinary winding of the secondary of said transformer, said first AC voltage being used for supplying an AC current to a system of rectifier circuit elements, the second voltage being an unbalancing voltage and being created by one of the ordinary phase windings which is also an unbalancing winding, said second voltage being used for changing the AC potential of one terminal of a load;(c) rectifying said first voltage with the help of rectifying circuit elements for providing a rectified voltage across the load;(d) changing the AC potential of the second load ter- minal by connecting said terminal to any point'of the unbalancing winding whereby* an additional AC. voltage superimposed on the DC. voltage is introduced across the load, said AC voltage being changed as the second load terminal is connected to different points along the unbalancing winding.12. The method as defined by Claim 11, which further com¬ prises the step of coupling terminals of at least one capaci¬ tor with the transformer and rectifier circuit elements, so that one capacitor terminal is connected to the point of star connection of the transformer secondary, and the other termin¬ al is connected to the same point of the rectifier system to which the first load terminal is connected, whereby the wave¬ form of the AC component across the load is changed as capaci¬ tance of the capacitor increases.13. A method for providing.an AC.voltage superimposed on DC voltage, the method comprising the steps of:(a) supplying an at least one-phase AC voltage to a modifying transformer with star-connected phase windings in the secondary;(b) modifying said AC voltage into a first and a second voltage with the help of said transformer, the first voltage being an at least one-phase voltage and being created with the help of at. least one ordinary winding of the secondary of said transformer, said first AC voltage being used for supplying an AC current to a system of rectifier circuit elements, the second voltage being an unbalancing voltage and being created by one of the phase-windings of the secondary which is an unbal¬ ancing winding, the second voltage being used for changing the AC potential of one terminal of a load;(_c) rectifying said first voltage with the help of rec¬ tifying circuit elements for providing a rectified vol¬ tage across the load;(d) coupling a first load terminal with rectifier circuit elements and a second load terminal with a point of star connection of the secondary of the transformer,OMPl whereby a DC voltage with a minimum AC ripple voltage is introduced across the load;e) changing the AC potential of the second load ter¬ minal by connecting said terminal to any point of the unbalancing winding whereby an additional AC voltage superimposed on* the DC voltage is introduced across the load, said AC voltage being changed as the second load terminal is- connected to. different points along the unbalancing winding,14. The method as defined by Claim 15, which further com¬ prises the step of coupling terminals of at least one capaci¬ tor with the transformer and rectifier circuit elements, so that one capacitor terminal is connected to the point of star connection of the transformer secondary, and the other terminal is connected to the same point of the rectifier system to which the first load terminal is connected, whereby the waveform of the AC component across the load is changed as capacitance of the capacitor increases.15. A method for providing an AC voltage superimposed on a DC voltage, the method comprising the steps of:(a) supplying an at least one-phase sinusoidal AC voltage to a saturable core reactor;(b) modifying said sinusoidal voltage into non- sinusoidal voltage with the help of said reactor and also controlling the value of said non-sinusoidal voltage by said reactor;(c) supplying said non-sinusoidal voltage to a modi¬ fying transformer with star-connected phase-windings in the secondary;Cd modifying said AC voltage into a first and a second voltage with the help of said transformer, the first voltage being an at least one-phase voltage, and BUR£4 being created with the help of at least one ordinary winding of the secondary of said transformer, said first AC voltage being used exclusively for supplying an AC current to a system of rectifier circuit ele- ents, the second voltage being an unbalancing vol¬ tage and being crea ted by one of the phase windings of the secondary which is an unbalancing winding, the second voltage being used for changing the AC poten¬ tial of one terminal of a load;(e) rectifying said first voltage with the help of rectifying circuit elements for providing a rectified voltage across the load;(f coupling a first load terminal with rectifier circuit elements and a second load terminal with a point of star connection of the secondary of the trans¬ former, whereby a DC voltage with a minimum AC ripple voltage is introduced across the load;(g) changing the AC potential of the second load ter¬ minal by connecting said terminal to any point of the unbalancing winding whereby an additional AC voltage superimposed on the DC voltage is introduced across the load, said AC voltage being changed as the second load terminal is connected to different points along the unbalancing winding;(h) coupling terminals of at least one capacitor with the transformer and rectifier circuit elements, so that one capacitor terminal is connected to the point of star connection of the transformer secondary, and the other terminal is connected to the same point of the rectifier system to which*the first load terminal is connected, whereby the waveform of the AC component across the load is changed as capacitance of the capacitor increases. 16. A method for providing an AC voltage superimposed on aDC voltage, the method comprising the steps of;(a) supplying an at least one-phase AC voltage to a modifying transformer with star connected phase wind-' ings in the secondary;(b) modifying said AC voltage into a first, a second and a third voltage with the help of said transformer, the first voltage being an at least one-phase voltage and being created with the help of at least one ordin¬ ary winding of the secondary of said transformer, said first AC .voltage being used for supplying an AC current to a system of rectifier circuit elements, the second voltage being an unbalancing voltage and being created by one of the ordinary phase windings which is also an • unbalancing winding, the second voltage being used for changing the AC potential of one terminal of a load, the third voltage being another unbalancing voltage and being created by one of the ordinary phase windings which is also an unbalancing winding, the third voltage being used for changing the AC potential of the other terminal of the load;Cc) rectifying said first voltage with the help of rectifying circuit elements for providing a rectified voltage across the load;(d) coupling a first load terminal with rectifier cir¬ cuit elements and a second load terminal with a point of star connection of the secondary of the transformer, whereby a DC voltage with a minimal AC ripple voltage is introduced across the load;(e) changing the AC potential of the second load ter- minal by connecting said terminal to any point of the unbalancing winding, whereby an additional AC voltage superimposed on the DC voltage is introduced across the load, said AC voltage being changed as the second load terminal is connected to different points along the unbalancing winding; fU E Cf) changing the AC.potential of the first load ter¬ minal by connecting one terminal of at least one capa¬ citor to. said first load terminal and connecting another capacitor terminal to any point of the unbal- 45 ancing winding, this point being different from the point of connection of the second load terminal, whereby an additional AC voltage superimposed on the DC voltage is introduced across the load, said AC voltage being altered while said other capacitor terminal is con- „ 50 nected to different points along the unbalancing winding.,17.. A method for providing an AC voltage superimposed on a DC voltage, the method comprising the steps of:(a) supplying an at least one-phase AC voltage to a modifying transformer with electrically connected5 phase-windings in the secondary;(b) modifying said AC voltage-into a first and a second voltage with the help of said transformer, the first voltage being an at least one-phase voltage and10 being created with the help of at least one ordinary winding of the secondary of said transformer, said first AC voltage being used for supplying an AC current to a system of rectifier circuit elements, the second voltage being an unbalancing voltage and being created15 by one of the ordinary windings which is also an unbal¬ ancing winding, the second voltage being used for changing the AC potential of one terminal of a load;(c) rectifying said first voltage with the help of 20 rectifying circuit elements for providing a. rectified voltage across the load;(d) coupling a first and a second load terminal with the system of rectifying circuit elements so -' hat a DC'25 voltage with a minimal AC ripple voltage is introduced across the load; BUR. _0M (e) changing the AC potential of the first load ter¬ minal using at least one capacitor connected to the first load terminal with one capacitor terminal and to any point of the unbalancing winding with the other capacitor terminal, whereby an additional AC voltage superimposed on the DC voltage is introduced across the load, said AC voltage changing while said other capaci¬ tor terminal is connected to different points of the unbalancing winding. | FRUSZTAJER B; LERNER M | FRUSZTAJER B; LERNER M |
WO-1979000429-A1 | 1,979,000,429 | WO | A1 | EN | 19,790,712 | 1,979 | 20,090,507 | new | F24H9 | null | B65D90, F24H1 | B65D 90/08, F24H 1/18B | STORAGE CONTAINER FOR HOT CONSUMPTION WATER | A storage container for hot consumption water. In such containers corrosion will occur which necessitates replacement. According to the invention special materials (1, 2) are recommended for such containers and a special type of supporting structure (3) which can be used in connection with the materials. | STORAGE CONTAINER FOR HOT CONSUMPTION WATERThe invention relates to a storage container for hot consumption water which container is of a circular- cylindrical shape with more or less flat end plates.Such containers have up to now been made primarily of metal plates which as known have the unfortunate charac¬ teristic that they are exposed to galvanic corrosion and other corrosion. Therefore, such containers must be regu¬ larly replaced. In order to avoid this the container may be lined with a corrosion resistant material. However, this is a complicated and costly procedure.The invention sets out to provide a container where these disadvantages are overcome. This object is attained by constructing the cylindrical part of a solid, electrically non-conductive material, using the same material for the end plates, and by supporting the end plates on the outer side by means of reinforcing elements, for example made of iron, and by designing the parts attaching the end plates to the cylindrical part in such manner that they connect the cylindrical part to the reinforcing elements.By making the cylindrical part of solid, electrically non-conductive material it is possible to avoid a costly lining of the container with such a material. Admittedly, the inside of the plates must consist of such a material, but as these plates are flat it will not mean any conside¬ rable increase in costs.By supporting the cylindrical part along its two edges by means of reinforcing elements and connecting parts, it is possible to obtain a suitable distribution of stress in the cylindrical part, as this will primarily consist in a circular stress caused by the internal pressure in the container. It has thus been possible to construct a container according to the invention with a reasonably low thickness of plate at the same time as observing the official safety requirements.The container may, however, be characteristic in that the reinforcing elements are made of circular iron plate which may be reinforced by means of ribs on the outside. This provides for a very simple and inexpensive construc-/,, W tion .A preferred embodiment of the invention is characteristic in that the electrically non-conductive material is as- bestos cement.When the reinforcing elements at each end consist of a circular iron plate, the container may, finally, be cha¬ racteristic in that the inlet and outlet are fitted to the end plates through holes in the iron plates, primarily by means of corrosion-proof fittings. In this way the risk of galvanic corrosion may be further reduced at the same time as it is ensured that the container will be water¬ tight.The invention will be further described in the following with reference to the accompanying drawings wherefig. 1 shows part of a section through one end of a container according to the first embodiment of the invention,fig. 2 the same in a second embodiment of the inven¬ tion,fig. 3 the same in a third embodiment of the inven¬ tion,fig. 4 a section in part of the end of a container according to the embodiment in fig. 1 or 2, in which there is a pipe fitting, andfig. 5 one embodiment of the container according to the invention, seen from the end on a reduced scale. Pig. 1 shows a cylindrical body 1 of asbestos cement, an end plate 2, also made of asbestos cement, a circular iro plate 3 , reinforced by means of U-irons welded on to it. The end plate 2 is fixed to the circular end opening of 5 the cylindrical body by means of threaded pins 5, which are screwed and possibly glued to the bottom holes along the edge of the cylindrical body 1, and the nuts 6. The joint is sealed by means of a gasket 7, which may for example consist of neoprene.10Pig. 2 shows the container in a second embodiment of the invention in which the joint between the cylindrival body 101 and the end plate 102 is made in another manner. In¬ stead of a flat gasket, a gasket ring 107 is used which15 is placed in an inside recess in the cylindrical body 101.In a third embodiment shown in fig. 3, the end plate 202 is reinforced and supported by a heavier solid, circular iron plate, which is not, however braced. The gasket ring 20 107 is in this embodiment placed in a groove 9 in the end plate 202.Pig. 4 shows part of an end plate 302 and the outside part of a circular iron plate 3 - These parts are provided with25 concentric holes 30 and 304, and concentrically herewith a cylinder-shaped reinforcement 305 is welded on to the circular iron plate 3. In the hole 303 is screwed a pipe 307 with a thread 306, consisting of stainless steel, more over, the pipe can be glued to the end plate 302. The pipe30 307 is, moreover, fixed in position by two nuts 308 and 309. Furthermore, the pipe 307 is connected at the inside, by welding, to an inside heating coil 310 of a non-corro¬ sive material, of which only a part is shown. The pipe 307 is connected at the outside to a pipe which is not35 shown._OM Pig. 5 shows one end of a container with a circular iron plate 403 fixed by screws 404 to the cylindrical part of the container, as described in fig. 1-3, however, only one screw is shown on the drawing. The circular iron plate 403 is provided with holes 405-410 for the connection of pipes, as shown. These connections are placed in the end plates which consist of the solid, electrically non-conduc¬ tive material, but the position of the holes 405-410 does not constitute part of this invention. The circular iron plate 403 is reinforced with U-irons 4ll-4l8 that are welded on to the circular plate.EXAMPLEA cylindrical container according to the invention may be ' constructed according to one of the embodiments shown in the drawings and have the following dimensions:Inside diameter = 500 mm Outside diameter = 5^3Inside length = 765Outside length = 810Thickness of end plates = 20Thickness of the cylindrical part = 3135 -The end plates are fixed by means of 24 pieces of 10 mm set screws placed in equidistant positions along the circumference. The reinforcing elements consist of circular plates. 5 mm thick that .are each reinforced by means of ribs in the shape of two set of U-irons 40 x30 x 3 mm that run at right angles to each other, welded on to the circular plates and placed as shown in fig. 5. The cylindrical part and the end plates are made of asbestos cement which is sold under the trade mark ETERNIT, pressure pipes, type 55 from Dansk Eternit- Pabrik A/S, 9000, Aalborg, Denmark. | C L A I M S1. Storage container for hot consumption water of a circular-cylindrical shape with more or less flat end plates, c h a r a c t e r i z e d i n that the cylin¬ drical part (1) consists of a solid, electrically non- conductive material, that the end plates (2) consist of the same material, that the end plates (2) are supported at the outside by reinforcing elements (3) for example made of iron, and in that the parts (5, 6), fitting the end plates (2) to. the cylindrical part (1), are so de- signed that they connect the cylindrical part (1) to the reinforcing elements (3).2. Container according to claim 1, c h a r a c t a r i - z e d i n that the reinforcing elements (3) at each en consist of a circular iron plate which may be reinforced by outside ribs (4).3. Container according to claim 1 or 2, c h a r a c t a r i z e d i n that the electrically non-conductive material is asbestos cement.4. Container according to claim 2 or 3. c h a r a c t a r i z e d i n that the inlet and outlet are fitted to the end plates through holes in the iron plates, primaril by means of corrosionproof fittings.OM IP | VOHNSEN V | VOHNSEN V |
WO-1979000431-A1 | 1,979,000,431 | WO | A1 | EN | 19,790,712 | 1,979 | 20,090,507 | new | C21B7 | C21B7 | C21B7 | C21B 7/10, C21B 7/16 | COOLED COMPONENTS FOR FURNACES | To improve the resistance to abrasion during use of cooled components, such as tuyeres and stack and bosh coolers, in furnaces a refractory or a metal with greater abrasion resistance than the metal, which is normally copper or copper alloy, used for the main body of the component is introduced during casting into the cast walls of the components. The added material may be in the form of one or more segments, a mesh, or in discrete particles and is located at or just below the surface at the nose (24) of the component. Examples of the materials which may be used are particles (44, 48) of so-called hard metals which comprise hard sintered carbides, such as tungsten carbide; stainless steel meshes and expanded elements (10, 40, 42) of varying thickness; and various compressed refractories capable of withstanding the thermal shock in a matrix of copper. | Cooled components for furnaces TECHNICAL FIELDThis invention relates to cooled components used in furnaces, particularly blast furnaces. BACKGROUND ARTAmongst the cooled components used in blast furnaces are the coolers, such as stack and bosh cool¬ ers, which are built into the refractory lining of the furnace, and tuyeres. These components are normally castings of copper or copper alloy.The noses of tuyeres and coolers inevitably be¬ come exposed to erosion by the burden of ore, coke, limestone, etc., in the blast furnace, the exposure becoming progressively greater as the furnace lining wears away.DISCLOSURE OF INVENTIONThe object of the present invention is to improve the resistance to abrasion during use of cooled compon¬ ents for furnaces. For this purpose according to the present invention there is introduced into the cast walls of such components during casting a refractory or a metal with greater abrasion resistance than the metal used for the main body of the component. The added material may be a refractory or a metal in the form of one or more segments, a mesh or in discrete particles and is located at or just below the surface at the nose of the component. The materials which may be used include(a) so-called hard metal which comprises hard sintered carbides, such as tungsten carbide,(b) stainless steel meshes of varying thickness, and(c) various compressed refractories capable of with- standing the thermal shock in a matrix of copper.The materials concerned are introduced into the casting by locating them in position in the mould before casting is commenced.A particularly suitable element is expanded metal from stainless steel or heat resistant steel. An ex¬ panded metal element has a certain amount of depth as well as length and breadth and the spaces between the steel strips can be varied to give the desired gap, filled with the cast copper or other material, thus providing the desired good heat conduction from the exterior of the element to the cooling medium.BRIEF DESCRIPTION OF THE DRAWINGSVarious forms of the invention will now be further described with reference to the accompanying drawings in which :Fig. 1 is part of an expanded steel element which can be used for the purposes of the invention;Fig. 2 is a side view of a blast furnace cooler according to the invention; Fig. 3 is a section on a larger scale taken on the line III-III of Fig. 2; Fig. 4 is a similar part section showing a differ¬ ent type of abrasion resistant material; andFig. 5 is a section through a tuyere according to the invention. BEST MODE OF CARRYING OUT THE INVENTIONFig. 1 of the drawings shows part of an expanded stainless steel element, generally designated by the reference numeral 10. This has been made in the usual way by cutting and expanding a sheet of stainless steel to give a lattice of strips 12 adjoined by flat nodes 14 which, as they are twisted out of the plane of the paper as seen in Fig. 1, give some depth to the structure as well as length and breadth. Spaces 16 between the strips 12 and nodes 14 will be filled by the cast metal in the finished article and will allow good conduction of heat to the surface of the cast component.The expanded sheet 10 can be cut to size and bent round very easily to form a curved or cylindrical shape.Suitable gauge for the stainless steel sheet from which the element 10 is made is 20 gauge (0.91 mm), and the stainless steel may be, for example, according to BS1449 EN58B.Figs. 2 and 3 show, on a smaller scale than that used in Fig. 1, a cooler, such as a bosh cooler, for a blast furnace. The cooler shown has a main cooling compartment 18 with inlet and outlet apertures 20 and 22, the nose end 24 of the cooler being cooled by means of a cast-in water pipe 26 having separate inlet and outlet 28 and 30. The characterising feature of the cooler is the expanded stainless steel element 10 which is included in the casting by locating it in position in the casting mould and casting the copper of the cooler round it. As shown in Fig. 2 it extends at length across the whole width of the nose of the cooler just underneath the surface and has been bent to go round the cast-in pipe 26 as shown in Fig. 3.In Fig. 4 can be seen the nose of a cooler in which, instead of using an expanded steel element 10, the abrasion resistant material consists of particles 48 of hard metal, i.e. mainly sintered tungsten carbide, such as is used for carbide tips of cutting tools. No parti¬ cular size or shape is needed for this particulate material and the particles may in fact be waste hard metal from the manufacture of carbide tips or used tips. The material 48 is embodied in the cooling element by placing it at the bottom of the mould or attached to the surface of the mould when the cooler is cast, so that the elements are embodied in the cast copper.Fig. 5 shows a tuyere of the sort having a main cooling chamber 30 surrounding an air-passage 32. The cooling chamber 30 has inlet and outlet apertures 46. The nose 34 of the tuyere is cooled by a separate cooling pipe 36 having an inlet pipe 38 leading thereto and a similar outlet pipe not seen in the section of Fig. 5. The nose is reinforced with two rings of expanded metal, an inner ring 40 which is inside the nose cooling pipe 36 and an outer ring 42 which surrounds the said pipe. Additionally hard metal particles 44 are embedded in the copper of the tuyere forwardly of the cooling pipe 36. It will be understood that any constructional form of cooler or tuyere can be used, the essential feature according to the invention being the provision of the abrasion resistant material at the nose of the device.Instead of using stainless steel, another form of heat-resistant steel could also be used, for example, according to AISA 430/S15.% J ric.A ( ' | CLAIMS :1. A cooled cast component for a furnace having a nose which, when the component is in position, is directed towards the interior of the furnace characterised in that there is introduced into the cast metal at the nose of the component a material with greater abrasion resistance than the metal used for the main body of the component.2. A component as claimed in claim 1 being a cooler for the wall of a blast furnace.3. A component as claimed in claim 1 being a tuyere. 4. A component as claimed in claim 1 wherein the said material comprises a refractory material.5. A component as claimed in claim 1 wherein the said material comprises a metallic element.6. A component as claimed in claim 5 wherein the said material comprises a stainless steel element.7. A component as claimed in claim 5 wherein the said material comprises a heat resistant steel element.8. A component as claimed in claim 5, 6 or 7, wherein the said element is a mesh or an expanded element. | BROWN & SONS LTD JAMES; WIDMER C; BROWN & SONS LTD J | WIDMER C |
WO-1979000434-A1 | 1,979,000,434 | WO | A1 | EN | 19,790,712 | 1,979 | 20,090,507 | new | B41M1 | B41N1, G03F7 | G03F7 | G03F 7/115 | SHALLOW RELIEF NON-BOTTOMING PHOTOPOLYMER PRINTING PLATE | A shallow relief non-bottoming printing plate is disclosed having a polymerized layer (12) of less than about 0.020 inch supported on a substrate (20). It includes a plurality of dispersed particles (18) interposed between the substrate (20) and the polymerized layer (12) sufficient to create small protuberances in non-image or background areas to prevent bottoming. The dispersed particles (18) are present in a size and concentration sufficient to create an array of selected protuberances in the background areas of the plate. Photopolymerizable elements, as well as processing techniques, are also disclosed for making such printing plates. | DescriptionShallow Relief Non-Bottoming Photopolymer Printing PlateTechnical FieldThe present invention relates generally to photo- polymerizable printing plates useful, for example, in letter¬ press and related printing operations, and more particularly to shallow relief, non-bottoming photopolymer printing plates and methods for making and using such plates.*Background Art Photopolymer printing plates have found widespread and successful use in letterpress printing processes, particularly in the newspaper industry. Conventional photo¬ polymer plates hold many advantages over prior art, metal etched printing plates. The time required to make the photopolymer plates, for example, is considerably shorter and, with the introduction of water developable photopolymers, problems relating to environmental contamination have been significantly reduced. In addition, photopolymer plates are much easier to handle and can be more readily and efficiently developed and processed than metal etched plates.Despite their widespread acceptance in the industry, however, photopolymer plates do suffer from the disadvantage of being relatively expensive, particularly when compared to the plates used in stereotype systems utilized by some of the large newspapers. Thus, there is a need in the industry for a less expensive photopolymer printing plate which will enable photopolymer printing systems to more efficiently compete with existing stereotype systems.Conventional photopolymer printing plates utilize photosensitive materials which are deposited on a supporting substrate such as 'metal or plastic. Experience has shown that acceptable printing quality can often only be accomplis when such photopolymer plates utilize photosensitive layers having a thickness greater than 0.020 inch. Without such relatively thick photopolymer layers, and the resultant high relief image areas that they produce, bottoming, e.g., the unwanted printing on white or non-image background areas, often results when thinner plates are used in letterpress machines.Although a number of techniques have evolved in an effort to solve this bottoming problem, none has proven to be entirely satisfactory. Obviously, the use of thick photopolymer layers of 0.020 inch or more is undesirable because of the added expense that is caused through use of more photopolymer. In some cases, ink repellant materials or even separate layers of ink repellant compositions have been incorporated in thinner photopolymer plates so that the non-image, background areas after development tend to reject any unwant accumulation and subsequent deposit of ink in white or background areas. The disadvantage of such techniques, of course, is that significant additional expense is added to the resultant plate (even where thinner photopolymer layers can be employed) because of the special ink repulsive layers, additional materials and additional manufacturing cos that are required.In other cases, highly expensive special printing press and extreme care in printing are required to minimize the bottoming problem. Attempts have even been made to overcome the bottoming problem by depositing a thin layer of photopoly exposing the first layer of photopolymer with a screen dot negative to create a series of small polymerized areas for background, and then depositing a second layer of photopolyme material over the first layer for use in creating image areas Such techniques, although partially useful in reducing the overall thickness of the resultant photopolymer layer, have the disadvantage of adding significant expense and of unnecessarily complicating the plate manufacturing process. Finally, grained substrates have heretofore been used in the printing arts for purposes other than the prevention of bottoming in photopolymer plates, but these teachings are of little or no value in the context of the present invention. Grained substrates have been used in lithographic plates, for example, to aid in making improved water receptive surfaces. Similarly, grained substrates have been used to strengthen metal printing foils or the like so that localized deformations caused by means of a typewriter, pen, pencil, embossing plate or the like will not cause the foil to be split, torn or creased.The problem, of course, with all such prior art techniques is that: (1) they fail even to recognize the nature and extent of bottoming problems that can occur in relatively thin photopolymer plates, and (2) they fail to provide a practical, inexpensive solution to the bottoming problem, and more specifically a solution that permits careful, but simplified, control over the height, size, density and spacing of background protuberances which applicants have found useful in eliminating the bottoming problem.Disclosure of InventionIn accordance with the present invention, therefore, a photopolymer printing plate is provided having a photopolymer layer that is substantially less thick, and thus far less expensive, than prior art photopolymer printing plates. Moreover, the printing plates of the present invention can not only be easily manufactured without adding significant time and expense to normal manufacturing techniques, but can be used on letterpress machines to produce printing material of high quality without unwanted bottoming occuring in back¬ ground areas.The present invention, therefore, is generally directed to shallow relief, non-bottoming photopolymer printing plates comprising (a) a substrate, (b) a binder layer coated on the substrate having a plurality of selected dispersed particles that create an array of selected pro¬ tuberances in the background areas of the plate, and relatively thin photopolymer layer that is coated on the binder layer, which upon development, provides the desired raised image or relief areas of the resultant plate. The present invention is further directed to photopolymerizable elements, to methods for making and processing such elements to provide the desired shallow relief, non-bottoming printin plates, and to printing processes which advantageously utili the shallow relief, non-bottoming plates of the present invention.Brief Description of the DrawingsThe novel features which are believed to be characteris of the present invention are set forth in the appended claims The invention itself, however, together with further objects and attendant advantages thereof, will be best understood by reference to the following description of various embodime of the invention taken in connection with the accompanying drawings, in which:FIGURE 1 is an enlarged cross-sectional view of a shallow relief, non-bottoming printing plate made in accordance with the present invention; andFIGURE 2 is a cross-sectional view of a photo¬ polymerizable element which may be utilized in accordance wit the present invention to provide a shallow relief, non- bottoming printing plate. It should be noted that FIGURES 1 and 2 are primarily illustrative representations, and the sizes and shapes of the various layers, substrate particles, and other components shown therein are not intended to limit the scope of the invention as further described hereinbelow and as set forth in the appended claims.Best Mode for Carrying Out the InventionThe shallow relief, non-bottoming printing plates of the present invention comprise a substrate, a binder layer carried by the substrate which imparts a controlled degree of surface roughness to the background areas of the developed plate, and a photopolymerized layer of photopolymer carried by the binder layer which upon development accounts for the raised image of relief areas of the plate. As set forth in greater detail hereafter, the non-bottoming characteristics of the shallow relief printing plates of the present invention result from the surface roughness characteristics of the back¬ ground areas of the developed plate, which, in turn, are carefully controlled through and dependent upon the size, density, spacing and type of particles dispersed in the binder layer, and the thickness and character of the binder layer itself.As shown, for example, in FIGURE 1, the shallow relief, non-bottoming printing plate 10 of the present invention has a photopolymer layer 12 which has been photopolymerized and developed with a suitable solvent to provide raised image areas 14. In accordance with the present invention, the back¬ ground areas 16 of the developed plate include a plurality of dispersed particles 18 that are held in place on substrate 20 by means of a separate binder layer 22. Substrate 20 can be a metal, such as aluminum, tin or steel, a synthetic polymer, such as a polyester, a paper sheet or other materials known to those skilled in the art.Binder layer 22 desirably has a balance of particular properties useful in the practice of the present invention. It is preferably compatible with the particular photopolymer 12 used, it readily adheres to both the substrate and photo¬ polymer; it secures the dispersed particles 18 in a fixed position and it does not wash away when the photopolymer layer 12 is developed, e.g., is substantially insoluble in the solvent used to develop the photopolymer. Although any material which meets the above-mentioned criteria could be used in formulating the binder layer, the following compositions, among others, have been found to be particularly advantageous when the photopolymer layer is a highly desirable water-developable photopolymer of the type disclosed in U.S. Patent No. 3,801,328: polyesters, polyurethanes, polyethylene-butadiene copolymers, polyvinyl acetate derivates, polyamides, epoxy resins, styrene-butadiene copolymers, mixtures of such copolymers and U E partially hydrolyzed polyvinyl acetate, unsaturated polyeste made, for example, from diethylene glycol, maleic anhydride phthalic anhydride, mixtures of such polyesters and partiall hydrolyzed polyvinyl acetate, and mixtures of glyoxal and partially hydrolyzed polyvinyl acetate.The particles 18 that are dispersed in the binder layer 22 are desirably of relatively uniform size and should be sufficiently large to impart the desired surface roughness, but not so large as to make the resultant printing plate too thick (and thus unnecessarily expensive) or so large that they are incapable of being firmly held in a secure position by a relatively thin layer of binder. It has been determine that generally spherically-shaped particles having an averag diameter (e.g., particle size) of between about 5 to 70 micr and preferably 20 to 40 microns, provide the desired array o selected protuberances and surface roughness when dispersed a binder layer having an overall thickness less than the ave height of the dispersed particles. The use of particles hav particle sizes in the desired ranges tend to create a plural of spaced protuberances in the background areas of the devel plate between 5 and 70 microns, and most preferably between 20 and 40 microns. Although any number of particle materials are suitable for use in the present invention, gla Teflon polytetrafluro-ethylene, and alumina beads have bee found to be particularly suitably, and Teflon most suitabl because of its ink repellant characteristics.It should be noted that the undesired bottoming is effectively eliminated in the printing plates of the pres invention because of the surface roughness characteristics created in the background areas of the developed plates by reason of the selected particles dispersed in the binder laye The use of ink repellant particles, of course, enhances this non-bottoming effect by preventing ink from depositing on the surfaces 24 of the particles, and instead accumulating, if a all, in the recess areas 26 between adjacent particles 18.OMP The spacing or average distance between particles 18 , therefore, is most preferably controlled in the practice of the present invention because the spacing or average distance between dispersed particles 18 also affects the extent to which the unwanted bottoming can be eliminated. It has been found, for example, that when the spaced d between adjacent particles is too large, ink which accumulates between the particles can transfer to paper during printing to cause bottoming. On the other hand, if the concentration of particles is too high, and the resultant spacing d too small, binder 22 is incapable of keeping the particles in place.A number of competing considerations, therefore, determine the ideal density and concentration of dispersed particles 18 for any given application. The particles should be sufficiently close to permit surface tension effects to hold accumulated ink between adjacent particles, rather than transferring to paper during the printing cycle. At the same time, the spacing should not be so close as to eliminate the effect of antihalation materials dispersed in the binder layer 22 or so close that the binder 22 is incapable of holding the dispersed particles in place.It has been determined for most applications that the average distance d between the dispersed particles 18 should desirably be maintained between about 5 microns to 1,000 microns, and most preferably between about 30 microns and 400 microns in order to achieve the desired balance of properties set forth above. The average distance between dispersed particles and the height of the desired protuberances (e.g., surface roughness) can be effectively measured using a surface profile meter which scans the surface of the plate before application of the photopolymer layer and provides a plot of the height and spacing of surface protuberances. For any given selection of particles, binder and photopolymer, therefore, the most effective density of particles to eliminate bottoming can be selected in accordance with the present invention.As noted above, antihalation compositions, such as red iron oxide, can also be dispersed in binder layer 22 togethe with the dispersed particles 18 used to eliminate the* bottoming problem. By incorporation of such antihalation compositions directly into the binder layer, the cobtly.and time consuming dichromate treatment or other forms of anti¬ halation treatment of the substrate 20 can be eliminated, thus reducing overall plate manufacturing time and cost.Further savings can be achieved through the present inventi because relief image 14 of lesser height than conventionall required to eliminate bottoming is required, and thus, a lesser amount•of photopolymer 12 is required to manufacture each plate. In that regard, photopolymer layers 12 in the range of about 9 to 16 mils, as contrasted with equivalent lay of 20 mils in conventional photopolymer plates, have been foun to be suitable for use in letterpress applicantions without the adverse effects of bottoming occuring in background areas. The substrate 20 is typically between about 8 to 10 mils in thickness, . and the binder layer 22 between about 5 to 60 microns in thickness, with the particles 18 projecting above the binder layer as discussed above.Because the printing plates of the present invention are less thick and utilize less photopolymer than conventiona photopolymer printing plates, they can be more readily processed in lesser time than is required to process conventio photopolymer plates. Indeed, it has been determined that printing plates manufactured in accordance with the teachin of the present invention can be exposed, washed-out, and drie in as little as 4 1/2 minutes per plate, in comparison to 7 or more minutes per plate for conventional photopolymer plates, which results in a substantial savings to persons employing such plates in their printing operations. in order to produce the photopolymerizable element 30 shown in FIGURE 2, selected quantities of antihalation and non-bottoming particles (e.g., iron oxide and glass, Teflo or alumina beads) are dispersed in the binder and coated onto substrate 20. Then after drying a suitable photopolymer layerf O 12 is cast onto the plate over binder layer 22, smoothed and then dried.It should be appreciated that the present invention is not directed to any specific photosensitive composition, binder composition, support material or combinations thereof; rather, the present invention is directed to the utilization of any or all conventional photosensitive compositions and substrate materials in the manner disclosed herein to provide shallow relief, non-bottoming printing plates. In addition, other conventional techniques such as the use of separate antihalation and adhesive layers, the etching or abrasion of substrate surfaces, the use of bump exposure or C02 condition- ing, and post exposure curing and treatment of the resultant printing plates may be used in conjunction with the shallow relief, non-bottoming printing plates disclosed herein and their methods of production and use.Practical embodiments of the present invention are illustratively shown in the following examples, wherein all percentages and parts are by weight unless otherwise indicated.Example 1A. Partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 82.0 mol%)(14 parts) is added to 86 parts of water at 60°C under stirring Temperature is raised to 90°C and the solution is stirred for one hour.B. Red ' iron oxide (PN 5097, Pfizer Co. ) (50 parts) is mixed well by means of ball-milling with 50 parts of 20 percent of partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 82.0 mol%) in water for 24 hours.Example 2Carboxylated styrene-butadiene copolymer emulsion (Dow Latex SD-655 solids percent 44%) (20 parts) is added slowly to 67 parts of partially saponified polyvinyl acetate solution which is described in Method A under stirring, and0MP1 W1P0υ agitation is continued for 30 minutes. Then, 3 parts of red iron oxide solution which is described in Method B, and 10 parts of Teflon powder (maximum particle size, 30 microns) are added to the resulted solution and the solution is stirred for 30 minutes. This solution is cast on an oil-free 10-mil thick aluminum plate and dried for 2 minutes at 180°C to form th2 layer 35 microns in thickness.Example 3Carboxylated styrene-butadiene copolymer emulsion (Dow Latex SD-655) (17 par,ts) is added slowly to 75 parts of partially saponified polyvinyl acetate solution which is described in Method A under stirring, and agitation is continued for.30 minutes. Then, 3 parts of ed iron oxide solution which is described in Method B, and 5 parts of Glass beads (maximum particle size, 50 microns) are added to the resulted solution and the solution is stirred for 30 minutes. This solution is cast on an oil-free 6.5-mil thick Tin plate and dried for 2 minutes at 180°C to form the layer 35 microns in thickness.Example 4Methylated me'thylol melamine in water (commercial name; Resloom M-75, solid 60%, by Monsanto Co.) (0.5 part) is added to 87 parts of 20 percent of partially saponified polyvinyl acetate (average polymerization degree, 500; saponifi cation degree; 88.0 mol%) in water, and 3 parts of red iron oxide solution which is described in Method B and 10 parts of Teflon powder are added to this solution. After 30 minutes agitation, 0.2 part of p-Toluene sulfonic acid is added to the resulted solution and the solution is stirred for 15 minutes. This solution is cast on an oil-free10-mil thick aluminum plate and dried for 2 minutes at 160°C to form the layer 35 microns in thickness.Example 5Red iron oxide solution (3 parts) which is described in Method B and 3 parts of dispersible Alumina (commercial name: Dispal M, by Philadelphia Quartz Co.) are added to 65f OMPI parts of 20 percent of partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 82.0 mol%) , and the solution is stirred for 30 minutes. Twenty-nine parts of Glyoxal (40%) is added to the resulted solution under stirring and the solution is stirred for 15 minutes. This solution is cast on an oil-free 10-mil thick aluminum plate and dried for 3 minutes at 180°C to form the layer 50 microns in thickness.Example 6 Diethylene glycol. (23 parts) , aleic anhydride (10 parts) and phthalic anhydride (15 parts) are added into four-necked flask and materials arc heated slowly to 150°C under Nirtogen atmosphere and the temperature is raised to 190°C. After the mixture is reacted at 190°C for 1 hour, unreacted materials are evaporated under reduced pressure (150mm Hg) . Hydroquinone (0.002 part) is added to the reactants at 100°C. Molecular weight of this unsaturated polyester is 1000 and acid value is 20.Thirty-six parts of the unsaturated polyester which is mentioned above and 5 parts of styrene are dissolved in 55 parts of xylene and 0.1 part of benzoin iso-propylether is added to the resulted solution. After the solution is stirred for 15 minutes, 4 parts of Glass beads (maximum particle size, 50 microns) is added and agitation is done for 15 minutes. This solution is cast on a cleaned 7-mil thick polyester film and dried for 5 minutes at 130°C to form the layer 55 microns in thickness. After the film was dried, this is exposed to U.V. light (medium pressure Hg lamp; distance 4 feet) for 1 minute.Example 7A mixture of partially saponified polyvinyl acetate (average polymerization degree, 500; saponification degree, 82.0 mol%) (35 parts), water (30 parts) and Rose bengal (50 ppm of all components by weight) is kneaded in a kneader at 80°C to 90°C for 30 minutes. Then, this mixture is cooled to 60°C and a mixture of diethylene glycol dimethacrylateIΓUR T (10 parts) , B-hydroxyethyl methacrylate (24 parts) , hydroquinone (0.1 percent of total monomer by weight) and benzoin iso-propyl ether (1.0 part) is added and stirred for 30 minutes. The resulted photopolymerizable composition is cast on the plate which is described in Example 2. A polyester sheet is placed thereon and the resulted piled produce is passed between two rolls. After cooling, the polyester sheet is peeled off and the plate and dried in a dryer at 75°C for 30 minutes to form a photosensitive layer 11 mils in thickness.Example 8Polyalkyleneoxide which includes at least one ethylenic unsaturated group (XD-8753 by Dow Chemical) (100 parts) , diacetone acrylamide (15 parts) , pentaerythritol tetraacrylate (5 parts) , benzoin iso-propylether (2 parts) and p-benzoquinone (0.02 part) are mixed and heated to 70°C. Then, 16 parts of glyoxal (65%) which is preheated to 70°C is added to the mixture and followed by quick mixing. The resulted mixture is immediately coated on the plate which is described in Example 3 with a doctor blade and the plate is dried in a dryer at 70°C for 15 minutes to form photosensitive layer 10 mils in thickness.Example 9The unsaturated polyester (80 parts) which is prepared by the method in Example 6, 10 parts of diacetone acrylamide 10 parts of B-hydroxyethyl methacrylate, 15 parts of styrene are mixed well at room temperature. Two parts of Benzoin isopropylether and 0.02 part of p-benzoquinone are added to the mixture and the resulted solution is stirred for 30 minutes. This photosensitive material is poured on the plate which is described in Example 6 before processing. The photosensitive composition is squeezed with a doctor blade to form photosensitive layer 16 mils in thickness. A negative film is placed thereon and the resulted piled material is exposed to a 3,000 watt high pressure mercury arc for 50 seconds from a distance of 20 inches. After exposure, the negative film is strippedOM from the plate and the unexposed material is washed away with 0.2% caustic soda (temperature, 40°C) under the pressure of 30 psi for one minute and followed by drying for 2 minutes at 120°C to give a relief 11 mils in thickness. The printing was carried out with a Vandercook letterpress printing machine (Universal III) using an ink for letterpress (Flint Ink Co.), and showed excellent image quality without any smutting on non-image area.Example 10 The photopolymer plate made according to Example 7 is placed in a vacuum frame and exposed to a 3,000 watt high pressure mercury arc for 3 seconds from a distance of 20 inches. Then, a negative film is placed on the photopolymer plate and the plate is exposed to same actinic light through the negative film for 35 seconds. After exposure, the negative film is stripped from the plate and the unexposed material is washed away with water (temperature, 45°C) under the pressure of 40 psi for 2 minutes. The printing plate is dried at 120°C for 2 minutes to give a sharp relief printing plate.The printing was carried out with a Vandercook letter¬ press printing machine (Universal III) using an ink for letterpress (Flint Ink Co.) and showed excellent image quality without any smutting on non-image area.Example 11A negative film is placed on the photosensitive plate made according to Example 8 and the plate is exposed to a 3,000 watt high pressure mercury arc for 2 minutes from a distance of 20 inches. After exposure, the negative film is stripped from the plate and the unexposed material is washed away with 0.3% caustic soda (temperature 40°C) under the pressure of 30 psi for one minute. The printing plate is dried at 120°C for 2 minutes to give a sharp relief printing plate. The printing was carried out by the same method as described in Examples 9 and 10, and showed excellent image quality without any smutting or bottoming on non-image area. Example 12The average distance between dispersed particles and the height of protuberances for printing plates made in accordance with Examples 1-11 are measured using a surface profile meter (Dektak by Sloan) . The 1cm x 1cm sample is put on a sample holder and the surface is scanned at the speed of O.lcm/min. The correlation of the nature of non-bottoming and the distance between dispersed particles or size of particles was investigated using different concentrations of particles and different sizes of particles. The suitable range of average distance between two particles is 5 microns through 1,000 microns, preferably 30 microns through 400 microns. On the other hand, the range of height of protuberance is 5 microns through 70 microns, preferably 20 microns through 40 microns.Average Distance Between Two ParticlesRange (microns) over5-30 30-400 400-1000 1000Nature ofNo non-bottoming Fair Good Fair GoodAverage Height Of ProtuberanceRange (microns) over5-20 20-40 40-70 70Nature of NoNon-bottoming Fair Good Fair Good^BUO Of course, it should be understood that various changes and modifications to the preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made with¬ out departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifica¬ tions be covered by the following claims. | Claims1. A shallow relief printing plate comprising a photopolyme layer supported on a substrate, and a plurality of dispersed particles interposed between said substrate and photopolymer layer, said photopolymerized layer having raised image areas, said dispersed particles being present in a size and concentration sufficient to create an array of selected protuberances in the background areas of said plate.2. The printing plate of claim 1 -wherein said protuberances present in the background areas of said plate are of a height less than that of the raised image areas.3. The printing plate of claim 1 wherein said photopolymeriz layer has a thickness less than about 0.020 inch.4. The printing plate of claim 3 wherein said photopolymeriz layer has a thickness of about between 0.009 and 0.016 inch.5. The printing plate of claim 1 wherein said dispersed particles are carried by a binder layer which is compatible with both said substrate and said photopolymerized layer and which secures said dispersed particles in a fixed position.6. The printing plate of claim 5 wherein said binder layer is selected from the group consisting of (a) styrene-butadien copolymers, (b) polyesters, (c) glyoxal, and mixtures (a), (b) , or (c) and partially hydrolyzed polyvinyl acetate.7. The printing plate of claim 1 wherein said dispersed particles have an average particle size of between about 5 to 70 microns and are present in a concentration sufficient to provide an average distance between particles of between about 5 to 1000 microns. AD ORIGINALOMPI 8. The printing plate of claim 1 wherein said dispersed particles have an average particle size of between 20 to 40 microns and are present in a concentration sufficient to provide an average distance between particles of between about 30 to 400 microns.9. The printing plate of claim 8 wherein said particles are ink repellant.10. The printing plate of claim 2 wherein said protuberances present in the background areas of said plate are of a height between about 20 to 40 microns.11. The printing pl-ate of claim 1 wherein said dispersed particles are dispersed in a binder layer, have an average particle size of between about 20 to 40 microns and are present in said binder layer at a concentration sufficient to provide an average distance between particles of between about 30 to 400 microns.12. The printing plate of claim 11 wherein said dispersed particles are selected from the group consisting of glass beads, polytetrafluoroethylene powder or alumina powder.13. The printing plate of claim 12 wherein antihalation composi¬ tions are dispersed in said binder layer.14. The shallow relief, non-bottoming printing plate comprising a water-developable photopolymerized layer having a thickness less than 0.020 inch and supported on a substrate, and a binder layer carrying a plurality of dispersed particles interpose between said substrate and said photopolymerized layer, sai photopolymerized layer having raised image areas, and said dispersed particles being present in said binder layer in a 5 size and concentration sufficient to create an array of protuberances in the background areas of said plate having an average height between about 5 to 70 microns and an aver distance between protuberances of between about 5 to 1000 microns.10 15. A relief photopolymerizable element comprising a laminate of *photosensitive composition supported on a sub- strate, and a binder composition carrying a plurality of dispersed particles interposed between said substrate and said photosensitive composition, said dispersed particles 15 being present in a size and concentration sufficient to create a plurality of protuberances in the background areas of said element after exposure and development of said photosensitive composition to create a relief image.16. The photopolymerizable element of claim 15 wherein sai 20 plurality of protuberances have an average height between about 5 to 70 microns and an average distance between protuberances of between about 5 to 1000 microns, and where said photosensitive composition has a thickness less than 0.020 inch.25 17. The photopolymerizable element of claim 15 wherein the said binder layer is selected from the group consisting of (a) styrene-butadiene copolymers, (b) polyesters, (c) glyoxal, and mixtures (a), (b) , or (c) and partially hydrolyzed polyvinyl acetate.30 18. The photopolymerizable element of claim 15 wherein said dispersed particles have an average particle size of between 20 to 40 microns and are present in a concentration sufficient to provide an average distance between particles of between about 30 to 400 microns.'BL 19. The photopolymerizable element of claim 18 wherein said dispersed particles are selected from the group consisting of glass beads, polytetrafluoroethylene powder or alumina powder.20. The photopolymerizable element of claim 19 wherein antihalation compositions are dispersed in said binder layer.21. The photopolymerizable element of claim 15 wherein said photosensitive composition is in a layer having a thickness in the range of about 0.009 to 0.016 inch, and said binder composition and dispersed particles are in a layer having a thickness in the range of about microns.22. A process for making a photopolymerizable element which upon development will provide a photopolymer printing plate having raised image or relief areas and recessed background areas, comprising: applying to a substrate a layer of binder composition having a plurality of dispersed particles contained therein of a size and concentration sufficient to create an array of preselected protuberances in the background areas of said printing plate after development; and applying a layer of photosensitive composition having a thickness less than 0.020 inch over said layer of binder composition and dispersed particles.23. The process of claim 22 wherein said dispersed particles are preselected to have an average particle size of between about 5 to 70 microns and are present in a con¬ centration sufficient to provide an average distance between particles of between about 5 to 1000 microns. 24. The process of claim 22 wherein the surface characteris of said background area are controlled by the average particle size and concentration of dispersed particles adde to said binder layer. | NAPP SYSTEMS INC | HALLMAN R; KOICHI K; SAKUO O |
WO-1979000441-A1 | 1,979,000,441 | WO | A1 | XX | 19,790,712 | 1,979 | 20,090,507 | new | H02P7 | B60L15 | B60L15, H02P7 | B60L 15/08, H02P 7/28B | CONTROL CIRCUIT FOR A D.C.MOTOR | A motor control circuit includes a chopper circuit (11) including a main switching element (14) which is connected in series with the motor armature (12). The chopper is controlled by a Schmitt bistable circuit (34) which operates to switch the main switching element on when the actual motor current falls more than a set amount below a demanded level and off when the actual motor current rises more than a set amount above the demanded level, the demand level is determined by the driver's pedal controlled potentiometers (37, 38) but is required to be modified in accordance with the motor speed. Instead of using a mechanical speed transducer, the present invention includes a circuit (40) which is connected to the output of the bistable circuit (34) and produces a signal varying in accordance with the ratio of the on and off times of the main switching element. | - -TECHNICA FIELDThis 'invention relates to a control circuit for a d.c. motor.BACKGROUND ARTKnovn circuits have often included means sensitive to the speed of the motor in the form of a transducer mechani¬ cally driven by the motor (or by the vehicle transmission). Generally speaking the transducer produces an a.c. signal ■which varies in frequency with the speed of the motor. Such .a transducer is, however, considered to be an undesira¬ bly expensive component of the control system and it is an object of the invention to provide a control system of the general kind referred to in which no mechanical speed transducer is utilized.DISCLOSURE OF INVENTIONIn accordance with the present invention a d.c. motor control circuit includes a chopper circuit with a main switch element arranged to be turned on or off to control the supply of power to the motor and speed sensitive means including means sensitive to the ratio of the on and off times of the main switch element of the chopper circuit.The invention is particularly, but not exclusively, applicable to control circuits of the known kind in which there is a motor current demand signal generator which generates a demand signal, a feedback circuit for producing a feedback signal corresponding to the actual motor current and means for switching the main switch element on when the feedback signal falls more than a set amount below the demand signal and for switching the main switch element off when the feedback signal rises more than a set amount above the demand signal. In such a circuit the speed sensitive means may provide an input to the demand signal generator to vary the demand signal independently of a demand input to the demand signal generator from a driver's acceleratorO. PI pedal device or the like.Ivhere the motor is of the type having separate armatur and field windings, it is known to provide a separate chopper circuit for the field winding, so as to enable the field current to be reduced when the vehicle speed reaches a level that the armature back e.m.f. becomes such that the demanded armature current cannot be achieved. In such a system the signal which is generated to control the reducti of field current may also be employed as a signal which is indicative of speed.BRIEF DESCRIPTION OF PRAT-TINGSAn example of the invention is shown diagrammatically in the accompanying drawings in which:-Figure 1 is a block diagram of the control system,Figure 2 is a circuit diagram of an armature chopper circuit included in Figure 1,Figure 3 is a circuit diagram of a part of the control system of Figure 1, andFigures k to 6 are graphs showing the speed/maximum armature current characteristics of the control for forward motoring, braking and reverse motoring modes respectively.BEST MODS FOR CARRYING OUT THE INVENTIONReferring firstly to Figure 1 the system, which is for the control of a d.c. traction motor, with separately ex¬ cited field winding 10, makes use of an armature current chopper circuit 11 which controls the current flowing in the motor armature 12. A Hall-effect current sensing circuit 13 is used to produce a feedback signal correspond¬ ing to the actual current flowing in the armature.As shown in Figure 2 the chopper circuit 11 includes a main thyristor 14, a commutating thyristor 15 and a third thyristor iβ. The thyristor l connects one terminal of the motor armature 12 to a negative supply rail 17 via a mainOMPI fuse 18, the anode-cathode of the thyristor 2.h being shunted by a resistor 19 and a capacitor 20. The other terminal of the armature 12 is connected via a contact 21 to a positive supply rail 22. This other terminal of the armature 12 is also connected by a diode 23 and fuse 2. in series to the rail 17 to provide a current path for armature current during braking i.e. when the contact 21 is open. A recir- culation diode 25 connects the first-mentioned armature terminal to the rail 22 to provide a current recirculation path to carry continuing (but decaying) armature current when the thyristor 1 is not conducting.The thyristor 15 has its anode connected to the anode of the main thyristor Ik and its cathode connected via an inductor 26 to one side of a commutating capacitor 27 the other side of which is connected to the rail 17. The third thyristor 16 has its cathode connected to the rail 17 and its anode connected via a further inductor 28 to said one side of the capacitor 27.The armature current chopper circuit operates as follows:- When increased current flow is required in the armature, the main thyristor l^f- is fired. 1-Jhen reduced current is required, the thyristor l6 is fired and then, after a fixed delay, the thyristor 1 is fired. Before the capacitor lβ is fired, said one side of the capacitor 27 is at a positive voltage relative to the rail 1 . On firing of the thyristor iβ the capacitor 2 discharges through the inductor 28 and when it is fully discharged current continues to flow in inductor 28, reversing the voltage on capacitor 2 . The thyristor iβ automatically turns off when the capacitor 2 is fully reverse^charged. The delay before firing of the thyristor 1 is arranged to be long enough to ensure that the thyristor 16 has switched off* T/hen thyristor 15 is fired, since the capacitor is reverse charged armature current will flow through the inductor 26 into the capacitor 27, diverting all current from the thyristor lk and thereby allowing this to turn off. Current continues to flow into the capacitor2 until this is fully charged whereupon thyristor 15 turn off, armature current then being diverted through the diode 25.Figure 2 also shows a diode 30 and resistor 2 in ser between the rail 22 and said one side of the capacitor 27. These components serve to maintain the positive voltage on the capacitor 27 should the main thyristor l4 remain on fo a long period.Returning now to Figure 1, it will be seen that there are three drive circuits 30» 31 and __)2. which are respectiv associated with the thyristors 14, 15 and l . These circuits are described. in detail in British Patent Applica tion No. 5 /76 together with a delay circuit 33 whi triggers the drive circuit 31 a predetermined time interva after circuit 32 has been triggered.The drive circuits 30 and J2 are triggered by falling and rising edges respectively of the output signal of a Schmitt bistable circuit _\k with a minimum off time feed back circuit 35> also described in application no. 5459/7The input to the Schmitt bistable circuit 3 is from a differential amplifier 36* which is connected to compare voltage signal representing the demanded armature current and a voltage signal from the current transducer circuit 1 The amplifier __\6 produces an output proportional to the difference between these voltage signals. The armature current demand signal is produced in a demand signal generating circuit which includes two pedal- actuated potentiometers 37 and 38, operated by the driver' accelerator and brake pedals respectively. The signals from sliders of these potentiometers are applied to a motor/brake comparator circuit 39 which compares the two -5-signals and connects that which has the greater magnitude to be applied to the amplifier 36. The circuit 39 also provides a number of logic outputs which are used in a logic circuit (not described herein) controlling various contactors which determine the mode of connection of the field winding and the armature winding that provide the forward and reverse motoring and braking conditions. One such logic output 3 a provides a logic signal which is high when the motoring signal exceeds the braking signal.Two separate circuits 40 and 4l are used to determine the magnitude of the voltages which are applied to the potentiometers 37 and 38 and which therefore define the maximum demand signal. One such circuit 40 has an input from the output of the Schmitt bistable circuit 34, the mark-space ratio of the output of which is substantially proportional to speed at low speeds (i.e. up to the base speed at which the back e.m.f. of the armature is equal to the main battery voltage. The other circuit 4l is controlled by the circuits which cause weakening of the field current above this speed. These circuits include a differential amplifier 42 (operative during braking) which receives an input from the differential amplifier __\6 and compares this with a fixed level, a start up circuit 43, which prevents any signals reaching the amplifier 45, unless the output of the Schmitt trigger circuit 34 has been low for more than a predetermined time interval. The greater of the output signals from the amplifier 42 and the circuit 43 is applied, via a ripple rejection circuit 44 to a fur¬ ther differential amplifier 4 which produces 'the signal controlling circuit 4l and also controlling a field weaken¬ ing circuit 46. For the purposes of the present description no mention need be made of other control circuits 4 , 48, which are associated with the circuit 46 and act to boost weaken, or totally remove the field current demand signal produced by circuit 46, such circuits being described in - -detail in the aforesaid application no. 45459/7^. The output of the circuit 46 is applied to one input of a differential amplifier circuit 50 which compares it with a voltage signal from a field current transducer 1» The output of amplifier 50 is applied to another Schmitt bi¬ stable circuit 52 which has a minimum on-and-off time feed¬ back circuit 53• Th-e output of the circuit 2 is applied via an opto-isolator circuit _>k to the field current choppe circuit 35 which supplies current to the field winding 10 via a so-called forcing and reversing circuit 56 which controls the mode of connection of. the field winding.Turning now to Figure 3» it will be seen that the low speed demand shaping circuit 4θ includes an operational amplifier A., which is of the current differencing type (e.g. a National Semiconductors L 3900 integrated circuit operational amplifier). The amplifier A., has its inverting input terminal connected via a resistor R_ to the output terminal of the Schmitt trigger circuit 34 and its non-in¬ verting input terminal connected via a resistor R„ and a variable resistor R„ in series to a positive supply rail +V. Feedback around the amplifier A. is provided by a resistor R. and a capacitor C. in parallel and the output terminal of the amplifier AY. is grounded by a capacitor C„. The output voltage of the amplifier A., is thus linearly related to the mark-space ratio of the output of the Schmit bistable circuit 34. At very low speeds, when the mark-spac ratio is small, the output of the amplifier will be at a maximum, but at a mark-space ratio determined by the settin of resistor the output will start to fall linearly and eventually reaches zero when the output of the Schmitt bistable circuit 3 is continuously high (i.e. at the base speed refexred to above).OMPI The start-up circuit 43 of Figure 1 is represented in Figure 3 by the circuit surrounding the transistor _. This npn transistor has its emitter grounded and its base connected to the common point of two resistors R_ and R/- connected in series with a third resistor R_ between the ground rail and input terminal B (which is the output of the Schmitt bistable circuit 34). A capacitor C„ is connec¬ ted between the junction of the resistors R_ and R_ and the ground rail and the resistor R_ and capacitor C form, in combination, a delay circuit which prevents the transistor - from turning on unless the output of the Schmitt bistable circuit has been low for more than a predetermined length of time. The collector of the transistor Q- is connected via a resistor R<-, to the terminal A which is at the output of the amplifier 42 and a further capacitor C, connects the collector of the transistor . to ground.The differential amplifier circuit 42 of Figure 1 is represented by the circuit surrounding the amplifier A„ in Figure 3„ This amplifier A_ (which is again a current differencing integrated circuit operational amplifier, as are all the amplifiers shown in Figure )s has its inverting input terminal connected via a resistor RQ to the terminal A and its non-inverting input terminal connected by a resistor R_Q to the -t-Vrail. A feedback resistor R... connects the output and inverting input terminals so that the output of amplifier A„ falls linearly with increasing input to terminal A.The ripple rejection circuit of Figure 1 is represented in Figure 3 by a resistor R_ „ and canacitor C_ connected in . __> series between the cathode of a diode D. , with its anode connected to the output of the amplifier Λ , and the non- inverting input terminal of an amplifier A„ representing the amplifier circuit 45 of Figure 1. A further diode D? has • its cathode connected to the cathode of the diode D__, and its anode connected to the collector of the transistor Q . The cathodes of the diodes D. , D2 are connected by a resistor R._ to the inverting input terminal of the ampli fier A_ which has a feedback resistor R . between its output terminal and its inverting input terminal. A resistor R_ _ connects the non-inverting input terminal of the amplifier A„ to the +V supply rail.During motoring, at below base speed, the transist Q.. , will be on so that no signal can pass from terminal A the inverting input terminal of amplifier A_. At base sp and above, the transistor Q.. remains off and the current applied to the inverting input terminal of amplifier A„ exceeds the bias current to the non-inverting input termi ssoo tthhaatt tthhee oouuttppuutt ooff aammpplliiffjier A„, falls linearly with rising voltage at terminal A,The output of amplifier A is connected by a resisto R-g to the non-inverting input terminal of an amplifier A. which has a feedback resistor R._ connected between its output terminal and its inverting input terminal. The no inverting input terminal of amplifier A. is also connecte via a resistor R „ and a variable resistor R..q in series to the +V supply rail and the terminal 39 _ is connected v aa rreessiissttoorr RR„„00 <a•nd a diode D„ in series to the non-invert input terminal.The output terminal of the amplifier A. is connected by a resistor R_. to the base of an npn transistor 0_ whi has the accelerator pedal potentiometer 37 connected betw its emitter and ground a resistor „ is connected betwee the collector of the transistor Q2 and the ÷V rail, and a resistor „„ and a variable resistor „, in series are connected between the base of transistor Q and the groun rail. A resistor connects the output terminal of the amplifier A_ to the base of the transistor Qp.OM Similarly, for the brake pedal potentiometer 38, there is another npn transistor Q„, the potentiometer 38 being connected between the emitter of this transistor Q and the ground rail. The base of the transistor Q is connected to the output terminal of amplifier A. by a resistor » to the +V rail by a resistor R 7 and to the ground rail by a resistor 2g and a variable resistor Rpo in series.The circuit described thus far operates as follows :-In forward motoring, at the lowest end of the speed range the output of amplifiers A_ and Ar are both high so that a maximum demand signal range is available. As speed increases the average value of the signal at terminal C increases and finally reaches the point where the current flowing into the inverting input of the amplifier A. exceed that flowing into the non-inverting input and the output begins to fall, thereby reducing the current in resistors R2 » *^2anci thus reducing the voltage at the emitter of transistor Q.2# Such reduction commences at point B__. in Figure 4 and the slope -S of the falling characteristic depends on the gain of the amplifier A1_ and the relative values of the resistors R„.__,, and ^2 + ^24* ^ben. the output of the amplifier A reaches zero, the voltage at the emitter of transistor Q7 is deter¬ mined by the resistors ^. and Jl__ ÷ 2Λ» This occurs at point B in Figure 4.As speed continues to increase the voltage at the output of amplifier A falls. ntil the current flowing into the in-verting input terminal of the amplifier A ~,,r is greater than that flowing into the non-inverting input hereo , whereupon the output of amplifi2r A,, starts to fall. This occurs at the point B i Figure 4, the slope S0 for speeds above this point being determined by the gains of amplifiers A„ and A^ and the relative values of the resistors ?.m_ . and ?;„ -*- R„-, . - -In braking mode the signal on the potentiometer 38 is reduced in similar fashion but there is only one break¬ point Bj, , since amplifier A. takes no part in the generatio of this signal. In braking mode amplifier A? comes into effect and amplifiers A„ and A with their' surrounding components determine the break point B.. Since, in braking the battery voltage may rise to a much higher level than in motoring, less field weakening is required and the break point B. may therefore occur at much higher speed. To compensate for this, the connection from terminal 39a, to th amnlifier A, provides extra bias current during motoring, which is not present during braking.Figure 3 also shows a circuit arrangement which limits speed when reverse motoring has been selected. This arrang ment includes an amplifier A_, the inverting input terminal of which is connected by,two resistors R __. and R 2 in serie to the terminal C. A resistor „„ connects the non-inverti innut terminal of the amplifier A_ to the +V rail and feed- back is provided by a resistor R , and capacitor C,- in parallel so that the amplifier operates as an averager like amplifier A . The output terminal of the amplifier A_ is connected to the cathode of a diode D, , the anode of which is connected to the base of transistor Q .To disable the amplifier A_ except during reverse motor ing, a transistor Q., has its emitter grounded and its collector connected via a diode D_ to the common noint of s the resistor R ±. and j><-. The transistor is switched on whenever reverse motoring is not selected y an output D from a direction selection logic circuit 6θ (see Figure l) , the base of transistor -,,r being connected to the common point of two resistors R connected in series between terminal D and ground , l-.Tien transistor Q^ is off, i.e. in reverse motoring mode, the output of the amplifier A_ falls steeply for speeds above the required limit (set by the choice of resistor R_„) as shown in Figure 6. hen transistor Q, is on, the output of amplifier A is high and diode D. prevents it having any effect on the control._QMP1 | AMENDED CLAIMS (received by the International Bureau on 2 May 1979 (02.05.79))1, A motor control circuit including a chopper with a main switch element arranged to turn on and off repeatedly to control the motor current and incorporating a speed sensitive means, characterised in that said speed sensitive means includes means (4θ) sensitive to the ratio of the on and off times of said main switch element (l4) and provides an output varying with speed which is used to modify a demand signal controlling the chopper,2, A motor control circuit as claimed in claim 1 further characterised by comprising a motor current demand signal generator, a feedback signal generator for generating a feedback signal related to the actual motor current and a control circuit for causing the main switch element to be turned on when the feedback signal falls more than a set amount below the demand signal and for causing the main switch element to be turned off when the feedback signal rises more than a set amount above the demand signal.3» A motor control circuit as claimed in claim 2 further characterised in that .said ratio sensitive means is connected to the output of the control circuit.4. A motor control circuit as claimed in claim 3 further characterised in that the ratio sensitive means is an operational amplifier ( - or A ) with an input resistor (R__. or R.-) and a feedback circuit consisting of a resistor (R. or R^j.) and a capacitor (c. or C^) in parallel,, STATEMENT UNDER ARTICLE 19Claim 1 has been amended to make it clear that the speed sensitive means produces an output signal which is used to modify a demand signal controlling the chopper. This is clearly disclosed in the specification as filed . see page paragraphs 2 and 3«<aS | BOXER T; LUCAS INDUSTRIES LTD; LUCAS IND LTD | BOXER T |
WO-1979000449-A1 | 1,979,000,449 | WO | A1 | EN | 19,790,726 | 1,979 | 20,090,507 | new | H05B37 | H05B41, H05B39 | G05F1, H05B41 | H04B 41/392V, H05B 41/04B2C, H05B 41/28, H05B 41/288K | VARIABLE INTENSITY CONTROL APPARATUS FOR OPERATING A GAS DISCHARGE LAMP | In a gas discharge lamp, when the current through the inductor (17) has increased to a point where the voltage drop across the resistor (15) exceeds the voltage of the reference source (23, 24), the comparator amplifier (20) triggers the monostabile multivibrator (18) causing the solid state switching device (14) to be turned off. This acts to collapse the magnetic field in the inductor (17) thereby causing a large flyback voltage to appear across the lamp (11) sufficient to light the lamp. At the end of the predetermined time period of the low output state of the monostabile multivibrator (18), its output turns the solid state switching device (14) on, allowing current to flow from the power supply (16) through the inductor (17) and the lamp (11), thereby maintaining the lamp in the lit state and increasing the magnetic field in the inductor (17). The current flow through the lamp, when the solid state switching device (14) is on, is in the opposite direction from the current flowing through the lamp when the solid state switching device is off. | VARIABLE INTENSITY CONTROL APPARATUS FOR OPERATING A GAS DISCHARGE LAMP Back-groung and Summary of the Invention Field of the Invention. This .invention relates to apparatus for operating a gas discharge lamp, such as a fluorescent, a mercury vapor lamp, a sodium lamp, or a metal halide lamp.(A) Variation of Lamp Intensity l. Prior Art BackgroundControl circuits for gas discharge lamps are known which obviate the need for the usual heavy and expensive series ballast devices, corresponding to the inductor in this device. in such circuits, switching elements are provided to periodically switch the direction of current through the lamp to reduce the deterioration or errosion of electrodes, and to ensure a high enough frequency of switching to reduce the requirement for the size of the ballast. Such circuits generally require two switching elements for each direction of the current.Attempts' have been made to fabricate the same type of circuit using only a single switching element to cause current reversal on the lamp.For example, the U.S. patent to D. B. ijsboom, No. 3,906,302, is directed to such an arrangement and incorporates an inductor in parallel with the lamp, which lamp is in series with a switching device. Such a switching device is generally operated at relatively high frequencies, such as 20 kHz. A significant disadvantage of this prior art device is that its control circuitry does not provide for varying the intensity of the lamp.2. Invention SummaryThis disadvantage is eliminated in this invention, in which, a gas discharge lamp and an inductor or choke coil are connected in parallel with one another. One side is 5 connected to a power source and the other side is connected to the collector of a transistor switch. The emitter of the transistor is connected to one end of a resistor, and the other end of the resistor is connected to10 ground. The base of the transistor is connect to the output of a monostable or one—shot multivibrator. The input to the one-shot multivibrator is connected to the output of a comparator amplifier. The multivibrator15 operates in such a way that when the input to the multivibrator is high, th-e multivibrator i triggered and its output goes low for a predetermined amount of time, after which its output returns to the high state. The two20 inputs to the comparator amplifier are connect in such a way that one input is connected to the emitter of the transistor and the other input is connected to a selectively variable reference voltage source. The circuit25 components and the time delay of the multivibrator are chosen in such a way as to provide a relatively high rate of switching on the base of the transistor, approximately 2 to 40 kHz.30 The alternating current flowing through th gas discharge lamp has no direct current component. As a result, the usual life of the lamp is increased by maximizing the life of the electrodes since a direct current componen35 of lamp current causes excessive cathodic heating of one of the two electrodes and reduces the life of that electrode.A significant feature of this invention is that the intensity of the lamp may be varied 5 by varying the reference voltage at the input of the comparator amplifier. In one embodiment this function is provided by a potentiometer connected between the reference voltage and the input to the comparator amplifier. In10 another embodiment, a photo conductive resistor is used in the voltage dividing input circuit- to the comparator amplifier to automatically vary the intensity of the gas discharge lamp in response to the ambient light intensity.15 A further aspect of this invention features the use of multiple lamps, instead of just one gas discharge lamp with no increase in the ignition voltage of the circuit. In order to ignite such lamps in sequence, for example in20 the case of two lamps, a capacitor is connected in parallel with one of the lamps. This capacitance acts to short out one lamp while the first lamp is ignited. After the first lamp is ignited, all of the ignition voltage supplied25 by the coil will appear across the second lamp, and cause the second lamp to ignite. After the second lamp is ignited, the capacitor has a comparatively high impedance, and is therefore effectively out of the circuit.30 Another feature of this invention features the use of a Zener diode, metal oxide varistor, or similar device connected across the transistor collector and ground. This varistor protects the transistor from35 transient surges in electrical power in the circuit by shorting out any transient voltages which exceed the magnitude of the brea down^rr^' ^- voltage of the varistor.In an additional embodiment of this invention, a low voltage power supply suitab 5 for powering the one shot multivibrator and comparator amplifier as well as supplying th reference voltage to the input of the comparator amplifier is supplied by a step-d transformer having as its primary winding th10 choke coil connected in parallel with the ga discharge lamp. According to this aspect of the invention a diode is connected between t secondary winding and a capacitor. The low side of the secondary winding and the other15 of the capacitor are connected to ground. T polarity of this diode is such that the volt supplied to the capacitor is independent of transient voltage which occurs in the induct during periods when the transistor is turned20 off.According to a further aspect of this latter embodiment, the electrodes of the gas discharge tube are preheated prior to igniti thereby extending the usable life of the gas 5 discharge tube. This is accomplished by connecting one of the lamp electrodes across minor portion of the high side of the choke winding. The other electrode is connected across a minor portion of the low side of th30 choke winding. This will ensure that a smal current flows through both electrodes just before the lamp is ignited, allowing the electrodes to warm up to a temperature close to the temperature achieved after ignition o35 the lamp.(B) High Power Factor Lamp Circuit^S 1. Prior Art BackgroundThe prior art lamp control circuits typically operate from a DC source, either from batteries or from a rectified and filtered AC source. In the latter instance, the filtering required results in a poor power factor, making the circuits unacceptable in certain applications. 2. Invention SummaryThis problem is solved in a second verion of the invention in which the two inputs to the comparator amplifier are connected in such a way that one input is connected to the emitter of the transistor and the other input is connected to the AC power supply. The circuit components and the time delay of the multivibrator are chosen in such a way as to provide a relatively high rate of switching on the base of the transistor, approximately 20 to 40 kHz.A significant feature of the second version of this invention is that the current of the lamp is varied precisely in relation to the AC line voltage, so that the power factor of the circuit is high.A further aspect of the second version of this invention features the use of a secondary winding on the lamp ballast which,, through a diode, charges a capacitor. This capacitor is isolated from the rectified AC power line by a diode. When the AC power voltage crosses zero volts, that is, when the rectified AC voltage is near its null point, the isolation diode becomes forward biased, and the charge on the capacitor prohibits the rectified AC voltage from nulling. Because a gas discharge lamp increas.es in resistance at a power voltage null, the capacitor used to prohibit nulling 5 avoids this high- resistance load characterist and thus protects the solid state switching device.In one embodiment of this second version this invention, a low voltage power supply 0 suitable for powering the one-shot multivibra and comparator amplifier may be supplied by a second step-down transformer having as its primary winding the choke coil connected in parallel with, the gas discharge lamp. 5 (C) Starter Aid Circuit1. Prior Art BackgroundAnother problem with prior art circuits h been that the fly back voltage during current reversal required to ignite the lamp when the ^ circuit is first activated must be large enou to generate a sufficiently strong .voltage gradient in the lamp to ionize the gas. This causes a large voltage to appear across the switching device which can damage the device ^ during ignition, thereby limiting the reliability of the control circuit.A further problem has been that it is oft necessary to reduce the voltage supplied to t circuit in order to ensure that only the opti 0 lamp voltage is supplied to the lamp. It has been found that such a reduction in supply voltage decreases the voltage gradient in the lamp for starting ignition of the lamp during current reversal. Therefore, with the 5 introduction of a step down auto transformer, the fly back voltage of the circuit must be increased to provide a sufficient voltage gradient in the lamp. Such an increase in fly back, voltage increases the wear in components in the circuit and a consequent loss of 5 reliability.2. Invention SummaryThese problems are solved in a third version of this invention in which one electrode of a gas discharge lamp is connected to the tapped 0 output of a step down auto transformer. One end of the auto transformer is connected to a rectified power source and the other end is connected directly to the collector of a transistor switch and to the other electrode of 5 the gas discharge lamp. The emitter of the transistor is connected to one end of a resistor, and the other end of the resistor is connected to the AC power supply return. The base of the transistor is connected to the output of a 0 onostable or one-shot multivibrator. The input to the one-shot multivibrator is connected to the output of a comparator amplifier. The two inputs to the comparator amplifier are connected in such a way that one input is connected to ^ the emitter of the transistor and the other input is connected to a voltage source which may be varied or controlled. A starter aid conductor is mounted adjacent the lamp and connected to the power supply return. Operation 0 of the circuit is the same as described above.A significant feature of the third version of this invention is that the voltage gradient in the lamp during ignition may be maximized without regard to the step down ratio of the 5 auto transformer, while the fly back voltage required for lamp ignition may be decreased. This reduces the fly back voltage across the transistor and therefore enhances the reliability of the circuit, while permitting the use of an auto transformer with, any desired step down ratio. (D) Symmetrical Lamp Voltage Regulation 1. Prior Art BackgroundYet another problem encountered in the prior art has been that the illumination intensity of the lamp for a given amount of power consumed is maximized only if the switching device operates to provide a symmetric voltage wave from the lamp. Typically, the magnitude of the voltage supplied the lamp determines the shape of the voltage wave form supplied to the lamp. As a result, in general, there is a .specific voltage which must be supplied through the circuit to the lamp in order to provide a symmetrical voltage wave form. The applicant has emperically found that the power efficiency of the lamp is maximized only when a symmetrical voltage wave form is supplied to the lamp, and that, for a high intensity mercury vapor lamp connected to a control circuit having a single switching element, a voltage supplied to the lamp of approximately 130 volts DC when warmed up, or 20 volts DC when cold, results in a symmetrical wave form. The problem of maximizing the efficiency of the lamp by providing a fixed supply voltage which ensures a symmetrical voltage wave form in the lamp is compounded because, if the control circuit is designed to provide the requisite 130—volt DC value for a symmetrical voltage wave* form in the lamp after warm up, then the time require to warm up the lamp after initial turn-on would be extended to become excessively long, and it is even possible that the lamp, after initial turn-on, would never reach its normal operative mode.Another problem is that, even though the control circuit may be designed to apply the • requisite voltage to ensure a symmetrical voltage wave form in th-e lamp, the requisite voltage may change during the life of the lamp due to change in lamp characteristics, and is different from lamp to lamp due to manufacturing tolerance variations. Furthermore, changes in lamp characteristics may result in a change in load impedance presented to the power supply, which may cause a change in the voltage output of the power supply, further complicating the task of attempting to supply the requisite voltage required to ensure a symmetrical voltage wave form in the lamp. Furthermore, power loss in the power supply itself occurs if the power supply input' impedance is reactive. Finally, even if the power supply is designed to provide the requisite voltage to the lamp for corresponding to a symmetrical voltage wave form in the lamp, variations in the voltage in in the power line supplying power to the power supply may cause the power supply to vary its voltage output from the desired requisite voltage. 2. Invention SummaryThe foregoing problems are solved in the fourth version of this invention in which a supply voltage feedback control loop including a power oscillator and a symmetry detector to 1Q control the voltage supplied to the control circuit so that it is maintained at a value which causes the on—time of the transistor to 5 equal its off—time, resulting in a symmetrica voltage wave form supplied to the lamp, maximizing the efficiency of the lamp. In or to prevent variations in lamp intensity cause • by variations in power line voltage, this10 invention uses a reference voltage feedback control loop to control the reference voltage supplied to one input of the comparator amplifier which minimizes variations in lamp intensity due to variations in power line15 voltage, while permitting the controlled variation of the reference voltage by the use in order to vary lamp intensity in a desired manner. The supply voltage control feedback loop and the reference voltage control feedba20 loop are combined in a voltage regulator whic is connected between the lamp control circuit and a constant current source providing 60-He alternating current. The voltage regulator provides further improvements in the efficien2 use of power by the lamp and its associated apparatus by presenting an input impedance to a 60-Hertz power source which is non-reactive, a feature facilitated by the power oscillator of the supply voltage feedback control loop.30 shut-down circuit is provided to temporarily shut down the voltage regulator before the occurrence of an over-voltage condition in or to protect certain components in the circuit.The advantages of the fourth version of t 5 invention are immediately apparent in that th supply voltage feedback control loop will alw assure a symmetrical yoltage wave form supplied to the lamp even if lamp characteristics change during the life of the lamp and even if different lamps are substituted having different characteristics, without necessitating any changes in the parameters of the components of the voltage regulator and control circuit of this invention. Thus, the efficient use of power for a given illumination intensity in the lamp is maximized because the voltage wave form supplied to the lamp is constrained to be symmetrical and because the voltage regulator presents an average input impedance to the power line which is non-reactive, thereby substantially eliminating reactive power losses in the voltage regulator. (E) Capacitive Discharge Ignition Circuit And Constant Power Regulation 1. Prior Art BackgroundThe problem of igniting the lamp becomes particularly acute when a high intensity high pressure gas discharge lamp is used, since such lamps require very high ignition voltages. One solution to the problem of providing a high voltage to ignite the lamp is to use a step-up voltage transformer connected to a capacitive discharge device which provides sufficient voltage for a short period of time to ionize the lamp without requiring the flyback voltage of the control circuit to be large. However, this creates further problems because the step-up transformer must be connected in series with the lamp, and, after the lamp circuit has assumed normal operation, the large winding ratio of the transformer will cause signi icant current to flow in the primary winding with- consequent power losses. This additional problem may be alleviated by opening up the primary winding after the lamp has ignited. However, this creates further problem because the secondary winding of the step-up transformer now acts as a second inductor in the lamp control circuit, impeding current flow10 through the lamp during flyback and further increasing the flyback voltage across the switching device, which may damage the switching device.Another problem in the prior art has been15 that when a high pressure sodium lamp is used with the lamp control circuit, its resistance is well known to increase during the life of th lamp, which increases power consumption of the circuit, and decreases the efficiency of the20 lamp circuit.2. Invention SummaryThese problems are solved in a fifth versio of the invention which includes the novel featu of a step-up pulse transformer having its 5 secondary winding connected in series with the lamp and its primary winding driven by a capacitive discharge circuit, the combination providing very high ignition voltage to the lamp, but including additional means preventing30 the inductance of the secondary winding from affecting the operation of the lamp circuit after the lamp is ignited and the lamp circuit is operating in its normal mode. This feature is provided by a rectifier diode connected35 across the secondary winding of the step-up transformer having its polarity oriented so that U ^:3> it provides an alternate current path when the switching device causes the voltage in the lamp control circuit to fly back. This invention further includes means for delaying the operation of the multivibrator in the lamp control circuit after power is first applied in order to permit the capacitive discharge device to become fully charged. This invention also includes a novel feature which makes the power consumed by the lamp control circuit independent of the effective lamp control circuit independent of the effective lamp resistance. This is accomplished by providing another transformer having its primary winding connected in series with the lamp and its secondary winding wound to an opposite polarity to provide a voltage proportional to the lamp current but of opposite polarity. This opposite polarity voltage is applied to one input of the comparator amplifier. As a result, the comparator amplifier senses only the voltage drop caused by the current through the primary winding of the inductive device. Thus, the lamp current does not affect the operation of the comparator amplifier, and thus the comparator amplifier is permitted to control current through the lamp circuit independently of the actual current to the lamp. This renders the power consumption of the circuit independent of effective lamp resistance. Brief Description of the Drawings The invention will be described in detail with reference to the accompanying drawings in which:Figure 1 illustrates a preferred embodiment of a-B 3 ΛZTO PI P control circuit for a gas discharge lamp shown in simplified form fox facilitating an understanding of the overall function of the control apparatus? Figure 2 illustrates a modified form of the circuit of Figure 1, in which the modification provides for automatically controlling the intensity of the lamp in response to variation in the intensity of the ambient illumination; Figure 3 shows four waveform plots labeled 3A, 3B,3C, and 3D which are characteristic of the control circu illustrated in Figure 1. Figure 3A is a plot of the current through the gas discharge lamp as a function of time, Figure 3B is a plot of the current through the choke or inductor as a function of time, Figure 3C is a ' plot of the collector current of the transistor as a function of time, and Figure 3D is a plot of the voltage across the gas discharge lamp as a function of time. In all of these plots, time is plotted on the horizontal ax and the voltage or current is plotted on the vertical axis;Figure 4 illustrates another modified form of the invention in which a single control circuit is effective to control a pair of gas discharge lamps connected in series;Figure 5 illustrates another modified form of the invention in which the choke or inductor windings are us as the primary windings of a step-down transformer which supplied power for the one-shot multivibrator and the comparator amplifier as well as the reference voltage to the input of the comparator amplifier. Figure 5 also illustrates the use of the primary coil as an auto transformer to supply current to the electrodes of the g discharge lamp as a source of preheating current prior t ignition of the lamp;Figure 6 illustrates a detailed circuit schematic including provision for (a) a step-down voltage supply to tlie lamp for matching the line voltage to the optimal lamps operating voltage and (b) a thermistor connected between the two inputs to the differential amplifier for sensing the temperature of the varistor device and protecting the varistor and transistor from destructive effects of transient power surges in the circuit;Figure 7 illustrates another modified form of the invention in which the reference voltage for the comparator circuit is derived directly from the output of a bridge which supplies the circuit with rectified AC power;Figure 8 shows two waveform plots labeled 6A and 6B, which are characteristic of the control circuit illustrated in Figure 7. Figure 8A is a plot of the current drawn by the lamp circuit from the full-wave rectifier showing both the instantaneous current levels and the average current level. Figure 8B is a plot of the current, both instantaneous and average, drawn by the full-wave rectifier from the power line;Figure 9 illustrates a modified form of the circuit of Figure 7 in which a capacitor is charged by a secondary winding on the lamp ballast and is utilized to prohibit the output of the rectifying bridge from reaching a null so that the lamp will not exhibit high resistance characteristics;Figure 10 is a detailed circuit diagram, similar to the circuit of Figure 6, but implementing in that circuit the additional features illustrated in the schematic circuit of Figure 9;Figure 11 shows three waveform plots labeled 11A, 11B, and 11C, which are characteristic of the control circuit illustrated in Figure 10. Figure 11A is a plot of the line voltage supplied to that circuit. Figure 11B iΞ a plot of the voltage at the output of the rectifying bridge and Figure 11C is a plot of the current drawn from÷ξVR bAl *JPMPJL - . W1PO ^ fl the power lines by the circuit of Figure 10;Figure 12 illustrates a detailed circuit schematic including provision for (a) a step down voltage supply to the lamp for matching the line voltage to the optimal lamp operating voltage and (b) a starting aid adjacent the gas discharge lamp;. Figure 13 illustrates the preferred embodiment of this invention in which the connection of the gas10 discharge lamp and the connection of the starter aid maximizes the starting voltage supplied to the lamp;Figure 14 is a schematic illustration of the progressive ionization of the gas in the gas discharge lamp during start up; 15 Figure 15 is a schematic diagram of an embodiment of this invention which includes a symmetry regulated supply voltage feedback control loop;Figure 16 illustrates time domain plots of the chok current and lamp voltage wave forms, similar to the 2 wave forms of Figures 3B and 3D, respectively, and showi by way of comparison the effect of the introduction of the symmetry regulated feedback control loop of Figure 15, in which:Figure 16A is a time domain plot of the choke current for setting X of potentiometer 23, corresponding to the plot of Figure 3B,Figure 16B is a time domain plot of the choke current corresponding to the setting X of potentiometer 23, but which is symmetry regulated,•3(1J Figure 16C is a time domain plot of the choke current for a setting Y of potentiometer 23 corresponding to the plot of Figure 3B,Figure 16D is a time domain plot of the choke current corresponding to the setting Y of JJ • potentiometer 23, but which is symmetry regulated,Figure 16E is a time domain plot of the symmet regulated lamp voltage wave form corresponding to the symmetry regulated choke current wave form of Figure 16B., andFigure 16F is a time domain plot of the symmetry regulated lamp voltage wave form corresponding- to the symmetry regulated choke current wave form of Figure 16D; Figure 17 is a schematic diagram of another embodiment of this invention including the symmetry regulated control loop of Figure 15 and further including a selective current regulating control loop and a protective shut-down circuit;Figure 18 is a schematic diagram of the quasi divider circuit used in the circuit illustrated in Figure 17;Figure 19 is a schematic diagram of the current convertor and power oscillator of this invention;Figure 20 includes time domain plots of various voltage and current wave forms in the circuit illustrated in Figure 19 wherein:Figure 20A is a time domain plot of the wave form of the input current I at the input to the current convertor of Figure 19,Figure 2OB is a time domain plot of the voltageV at the return terminal of the diode bridge of the current convertor of Figure 19,Figure 20C is a time domain plot of the rectified voltage Vn at the output of the diode bridge of Figure 19,Figure 20D is a plot of the total current output of the diode bridge of Figure 19, andFigure 20E is a time domain plot of the input voltage across the diode bridge of Figure 19; Figure 21 includes time domain plots of voltage and current wave forms in the power oscillator of Figure 19, wherein : Figure 21A is a time domain plot of the input current I similar to the plot of Figure 20A, but having its time scale considerably expanded, Figure 21B is a time domain plot of the collector voltage across the oscillator transistor of Figure 19,Figure 21C includes superimposed plots of V72Λ, the 20 kHz voltage in the power oscillator of Figure 19 Vg20 the 60-Hertz output voltage at the output of the diode bridge of Figure 19, and V_, the total voltage at the output of the diode bridge of ;Figure 19 including the 20-kHz ripple voltage superimposed upon the 60-Hertz output voltage,Figure 21D is a time domain plot of the voltage V_ at the negative input to the comparator amplifier of Figure 19, and V , the positive feedb to the comparator amplifier of Figure 19, Figure 21E is a time domain plot of lg20' ^e current through the snubbing capacitor at the diod bridge output of Figure 19, and of L,-, the curre through the inductor of Figure 19,Figure 2IF is a time domain plot of the curre through the power oscillator transistor of Figure Figure 21G is a time domain plot of the curre through the output diode of the power oscillator o Figure 19; •Figure 22 is a schematic diagram-of the voltage regulator of this invention which includes the current convertor of Figure 19;Figure 23 is an overall schematic block diagram of the preferred embodiment of this invention including th symmetry regulated control loop of Figure 15, the curre regulator control loop of Figure 17, a protective shut- circuit similar to that illustrated in Figure 17, and t voltage regulator of Figure 22; Figure 24 is a detailed schematic layout diagram of the circuit of Figure 23;Figure 25 is a block diagram of the shut-down protective circuit of Figures 23 and 24;Figure 26 is a schematic diagram of a lamp control circuit similar to that of Figure 1, but including a stap-up transformer having its secondary winding connected. in series with the lamp and its primary winding connected to a capacitive discharge device, in which the inductance of the secondary winding interferes with the - normal operation of the lamp control circuit;Figure 27 is a simplified schematic diagram of one embodiment of this invention including a step-up transformer having its secondary winding connected in series with the lamp and its primary winding connected to a comparative discharge device and further including means preventing the inductance of the secondary winding from interfering with the normal operation of the lamp control circuit;Figure 28 is a schematic diagram of another embodiment of this invention in which a transformer having one of its windings connected in series with the lamp facilitates regulation of the current consumption of the lamp control circuit independently of the effective lamp resistance; andFigure 29 is an overall detailed schematic diagram of the preferred embodiment of the control circuit of the invention including the features of Figures 27 and 28.Description of the Preferred Embodiment (A) Variation of Lamp IntensityReferring to the circuit illustrated in Figure 1, a gas discharge lamp 11, typically a low-pressure mercury vapor fluorescent lamp, having two electrodes 12 and 13, has its electrode 13 connected to an electrnoic switch shown as an NPN transistor 14, the collector of which is connected to electrode13, and the emitter connected to a resistor 15. The other end of the resistor 15 is connected to ground. The other electrode of the gas discharge tube 12 is connected to a DC power supply. This • supply will normally be a rectified AC source but is shown for simplicity in this figure as a batter 16 whose positive terminal is connected through on-off switch 19 to electrode 12 and whose negativ terminal is connected to ground. A choke or induc 17 is connected in parallel with the electrodes of the gas discharge lamp 12 and 13. The base of the NPN transistor switch 14 is connected to the output of a one-shot multivibrato 18. The monostable multivibrator operates in suc a way that when the input to the multivibrator is low its output is high, and when its input is high, the monostable multivibrator is triggered such tha its output goes into the low state for a predeterm finite length of time, after which the output of t multivibrator returns to the high state. The inpu of the multivibrator is connected to the output of comparator amplifier 20. The positive input of th comparator amplifier is connected through a conductor 21 to the emitter of the NPN transistor14, and the negative input of the comparator ampli is connected through a conductor 22 to a potentiom 23. Potentiometer 23 is connected to the positive end of a DC power source 24, and the negative end of the DC power source 24 is connected to ground.The operation of the circuit of Figure 1 is a follows. When the switch 19 is first closed, the current passes through the switch 19 and through t inductor 17. No current passes through the gas discharge lamp 11 because, until it is ignited by high voltage, th-e lamp remains nonconductive. The current through the inductor passes through the NPN transistor switch 14 and through the resistor 15 to ground. The current through the inductor 17 rises as a function of time until it reaches a level at which the voltage drop across the resistor 15 exceeds the voltage on the conductor 22. The voltage on the conductor 22 is determined by the potentiometer 23. When the voltage drop across the resistor 15 exceeds the voltage on the conductor 22, the comparator amplifier 20 senses a positive difference between its inputs and the output of the comparator amplifier 20 changes from the low to the high state. In response to the high output of the comparator amplifier 20, the one-shot multivibrator 18, is triggered and provides a low output for a short predetermined length of time. Thus, the transistor switch 14 will be turned off for the short period of time during which the base of the transistor received a low level signal from the multivibrator 18. The magnetic field in the choke 17 then collapses, resulting in a voltage potential across the electrodes 12 and 13 of the gas discharge lamp 11. This potential is sufficient to ignite the lamp and the lamp begins to conduct current.After the above-mentioned short predetermined length of time, the one-shot multivibrator output returns to its normally high level state, thereby turning the transistor switch 14 back on. At this instant in time, current begins to flow from the source 16 through the electrodes 12 and 13 of the gas discharge lamp 11 in the opposite direction to the current supplied before by the choke 17. TheOMPI^BRNATC^ magnetic field in the choke 17 also begins to buil up again as does the current through- the choke 17. This results in a rise in the collector current of the transistor 14 and an equal rise in current through the resistor 15. This rise in current wil cause the voltage drop across resistor 15 to rise • until the conductor 21 again exceeds the voltage on conductor 22. Again, the comparator amplifier will give a high output when this condition is reached, causing the output of the multivibrator 1 to go into the low state for the finite period of time thereby turning off the collector current of transistor 14. The magnetic field in the choke 17 will collapse at this time, thereby causing a curr to flow between the electrodes 12 and 13 of the gas discharge lamp 11 in a direction opposite to t direction traveled by the current when the transistor 14 was on. This condition will continu until the multivibrator output returns automatical to the high state.As may be seen from this description, this process will continue to repeat itself as the transistor 14 continuously is switched on and off until steady state conditions are achieved. One or more cycles of operation may be required to ionize the lamp and cause it to ignite.A varistor or high voltage zener diode 27 is connected between the collector of the NPN transis and ground, and serves to protect the transistor 1 from destructive breakdown in the event of lamp failure causing an open circuit between its terminals, or inadvertent unplugging of the lamp when the power switch 19 is closed. When the lamp itself is defective and causes an open circuit or when the lamp is removed, the voltage rise at the collector of transistor 14 produced by collapse of the magnetic field in the inductor 17 will be limited to the breakdown voltage of the varistor, a value selected to be within the safe limits of the collector- base junction of the transistor switch 14.A significant feature of the invention is that the varistor 27 serves the additional function of preventing ignition of the lamp until the lamp electrodes have been warmed up over a time period which is long compared to the operating period of the control circuit. Thus, the control circuits of this invention, without the varistor, would typically supply on the order of 1000 volts across the lamp in the fly back mode. Such high voltage applied to the lamp filaments when they are cold would be extremely deleterious since the electrodes would undergo a very high rate of change of temperature. The varistor is selected such that it breaks down for voltages exceeding 500 to 600 volts. At these lower voltages, the lamp 11 will not ignite until after the cathodes have been heated. Typically, a time delay of 3/4 second to one second is the amount of time needed to heat up the cathodes sufficiently for the lamp to ignite when supplied with 500 to 600 volts.Figures 3A, 3B, 3C, and 3D are plots of the steady state response characteristics of the circuit for two different levels of input power to the gas discharge lamp.Figure 3A is a plot of a single cycle of current through the gas discharge lamp as a function of time. The current is plotted on the vertical axis and the time is plotted on the horizontal axis. It will be understood that the current alternates through the lamp in a repetitive cycle. ' In the region of Figure 3A, denoted A , the transistor switch- 14 is in th-e off state and the collapsing field in the inductor 17 is forcing a current thro 5 the gas discharge lamp. The region A covers a period of time between tine T and time T . This time period is equal to the unstable period of multivibrator 18. In the region in Figure 3A deno B , the transistor switch 14 is on. The region B10 lies between the time T and the time T , after which the cycle repeats itself.In Figure 3A, the magnitude of the lamp curre in region A is shown to be roughly equal to the magnitude of the current in region B. Since, for15 reasons described above, there is no net DC curren through the lamp, the respective areas under the curves in regions A and B are equal. Thus, in the circuit operating mode illustrated by Figure 3A, the duration of the time periods A and B are rough20 equal. The operational mode shown in Figure 3A having approximately equal current flows in region A and B is advantageous since it maximizes the efficiency of the lamp and also minimizes the curr handling requirements for the switch transistor 14.25 This operating mode is achieved for a fairly narro range of DC voltage output of the power source 16 for a given lamp. The circuit of Figure 6 describ below provides a means for matching a given DC voltage to a plurality of lamp or lamps having30 different optimum voltages.Figure 3B is a plot of the current through th choke or inductor 17 as a function of time. The current through the choke is plotted on the vertic axis, while time is plotted on the horizontal axis.35 in the region of Figure 3B denoted A , at time T the transistor has been turned off and the current through- the ..choke is decaying as a unction of time until time T» . At time T , the transistor is turned on. The current through the choke in the region of Figure 3B denoted E increases until time T_ ___>, at which, time the transistor is turned back off, and the cycle repeats itself. The behavior of the circuit thus alternates between the behavior plotted in region A and the behavior plotted in region B.Figure 3C is the plot of the collector current of the transistor plotted as a function of time. The collector current amplitude is plotted on the vertical axis and time is plotted on the horizontal axis. In the region denoted A of Figure 3C, the transistor is off and therefore the collector current remains zero, from time T_. to the end of region A at time T,. In the region deonted B in Figure 3C, at time the transistor is turned on and remains on until time T_., which defines the end of region B. During this time, the collector current continually increases. At time T_ the transistor is again turned off and process repeats itself. Thus, the collector current is periodic in time. The current level indicated by the plot is equal to the voltage on the conductor 22 of Figure 1 divided by the resistance of the resistor 15 in Figure 1.Figure 3D is a plot of the voltage across the gas discharge lamp as a function of time. It is identical in shape to the lamp current shown in Figure 3A at the operating frequency of the circuit, i.e. the frequency at which the transistor switch 14 is switched on and off. This frequency is chosen so that its period is short compared to the ionization time of the lamp. A representative operating range is from between 20 to 40 kHz. At this high, frequency, the lamp appears electrically to be a resistor. Since the current through a resistor is linearly proportioned to the voltage across it, the lamp voltage and current wave forms are identical in shape.This high frequency operation has the ' significant advantage that the weight of the choke, shown in figure 1 as 17, may be considerably reduc below the weight of the typical chokes found in the usual fluorescent lamp circuits using 60 Hz AC sources. By way of specific example, a choke suitable for use at 20 kHz will weight on the order of 4 or 5 ounces whereas the corresponding choke for use at 60 Hz will weight 4 or 5 pounds. A significant feature of the invention is the selectively variable control over lamp intensity which potentiometer 23 provides. The power input t the lamp ( and the resultant lamp intensity ) are approximately proportional to the average magnitude of the lamp current, which is plotted in Figure 3A. This plot shows the current reversal during periods when the transistor is turned off, which occurs, for example, at time T_-.. Assume that a particular setting X of the potentiometer 23 in Figure 1, the voltage on conductor 22 in Figure 1 is lower than the voltage on the conductor at another setting Y of the potentiometer 23. The corresponding changes in the waveforms in Figures 3A, 3B, 3C, and 3D between the two settings of the variable resistor for effecting different levels of the lamp intensity are illustrated in these figures. In each figure, the waveform on the left is denoted setting 'X' and the waveform on the right in each figure is denoted setting Υ« .The manner in which this control is achieved with potentiometer 23 is as follows:The peak lamp current always occurs whenever the transistor is turned off, corresponding to times Ω and TR. This occurs whenever the sum of the choke current and lamp current passing through the resistor/ denoted 15 in Figure 1, causes a voltage drop across this resistor equal to the voltage on the conductor, denoted 22 in Figure 1. As states above, this occurrence causes the comparator amplifier, 20 in Figure 1, to give a positive output to the multivibrator, which in turn causes the multivibrator to turn the transistor off.The current passing through the resistor, 15 in Figure 1, is the collector current of the transistor. This current is plotted in Figure 3C, as the sum of the lamp current and choke current in region B.The peak collector current level is equal to the voltage on the conductor 22 in Figure 1 divided by the resistance of the resistor, 15 in Figure 1. When the voltage on the conductor 22 is increased or decreased, the collector current peak level will increase or decrease, respectively. Because the decay time of the current between time T_ and time T, is. slways the same, the minimum value of the collector current will also increase or decrease, respectively. Thus, the entire waveform of the collector current will be shifted either up or down, respectively, of which two exemplary waveforms are plotted for the two different potentiometer settings X and Y . The waveforms of the choke current and the lamp current will also be shifted up or down, respectively, as shown. This effect is the result of the fact that the collector current through the transistor is the sum of the choke current and lamp current, and the fact that the lamp current is proportional to the choke current.Thus, it may be seen that the lamp intensity, which is proportional to lamp current, is10 proportional to the voltage on the conductor 22. By changing the resistance of the potentiometer 23 - in Figure 1, the current supplied to the lamp 11 will change.The useful life of the gas discharge lamp is15 increased in this invention since the net DC component of current through the lamp during continued operation is approximately zero. This is achieved by virtue of the parallel inductance which has the property of maintaining a zero DC2 voltage drop across its terminals. Since this zero DC voltage is also maintained across the lamp, the DC current through the lamp will also be zero.Although the' circuit is particularly suited for use with low intensity, low pressure mercury25 vapor fluorescent lamps, it can equally well be used to control various other types of gas discharg lamps such as high pressure mercury vapor, high or low pressure sodium, and metal Halide lamps.Figure 2 illustrates a modified form of the invention effective to automatically control the intensity of the lamp, causing the intensity of illumination of the lamp 11 to be automatically controlled inversely proportional to the ambient illumination. This circuit is similar to that ofOJ ■ Figure 1 and similar reference numerals are provided for similar components in Figure 2 and succeeding figures. In lieu of the optentiometer 23 of Figure 1, a photosensitive resistor 25 or/ , similar photoresistive device is connected in series with- resistor 26 between the voltage source 24 and the differential amplifier 20.Alternatively, and infrared sensing device (not shown) capable of varying its electrical . resistance in proportion to the amount of infrared rays intercepted thereby, could be substituted for the photoresistor 25 to detect the presence of a human being in the vicinity of such sensor to cause illumination of the lamp 11 when the human being moves into the area adjacent the lamp.Figure 4 illustrates another modified form of the invention in which two gas discharge lamps 28 5 and 29 are connected in series with each other in a circuit otherwise similar to that of Figure 1. Herein, the lamps 28 and 29 are of similar capacity and typically low pressure mercury vapor fluorescent lamps of 22 watts each. The electrode 30 of lam ° 28 is connected directly to the electrode 31 of lamp 29. A capacitor 33 is connected across the electrodes 31 and 32 of lamp 29.When the lamps 28 and 29 are de-energized, they present a relatively high resistance thereacross. 5 Thus, capacitor 33 initially presents a short across lamp 29 at the operating frequency of the circuit, e.g., 20,000 cycles per second. Therefore, when starting, the voltage from inductor 17 is initially applied through the capacitor 33 and across the lamp 28 to ignite the same. After lamp 28 has become ignited, its resistance drops considerably and most of the voltage across inductor 17 now appears across lamp 29, causing it to likewise ignite. The resistance of lamp 29 is relatively small compared 5 to the reactance of capacitor 33 so that the latter has essentially no effect on the circuit during normal operation.The above arrangement minimizes the breakdown voltage requirement of the transistor switch 14, thereby enabling a relatively small and inexpensive transistor to be used.Figure 5 illustrates a further modified • embodiment of the invention in which a gas discharg lamp 35, typically a low pressure mercury vapor fluorescent lamp of approximately 22 watts, is provided. The electrodes 38 and 40 are of the heated type. Power is derived from a DC voltage source 16.An inductor 37 is connected in series with the transistor 14 and resistor 15 across the power supp 36. The electrodes 38 nd 40 of lamp 35 are tapped into sections 41 and 42 of the winding of inductor 37 to preheat such electrodes prior to ignition of the lamp. The inductor 37 also acts as the primary windi of a transformer and has an iron core 39 and a step down secondary winding 43 associated therewith. The winding 43 is connected in circuit with a diode 44 across a capacitor 45. The diode 44 is also connected through line 46 to the power input terminals of the comparator amplifier 20 and multivibrator 18. It is also used to supply the reference voltage to the potentiometer 23.The sections 41 and 42 of the winding of induc 37 enable the electrodes 38 and 40 to become heated before the lamp is ignited. This arrangement maximizes electrode life and prevents damage to the electrodes 38 and 40 due to the otherwise excessive rise of temperature at the start of a lamp operation.The polarity of the winding 43 is preferably such that the capacitor 45 is charged only when the transistor 14 is conducting. This arrangement insures that the particular voltage on capacitor 45 is independent of the variable flyback voltage developed by the inductor 37 when the transistor 14 is cut off.Figure 6 illustrates a detailed circuit schematic showing a number of circuit elements which were deleted from the simplified circuits described above to facilitate understanding of the overall operation of the invention. In addition, this figure illustrates several significant additional features of the invention. The circuit of Figure 6 is designed to operate from a standard 120 volt AC line connected to terminals 50 and 51. These terminals respectively connect to on-off switch 19 and current limiting resistor 52 to a full wave diode bridge rectifier 53 comprising diodes 54, 55, 56, and 57. The DC output of this rectifier is connected across a wave smoothing capacitor 58. The negative bridge terminal is connected to ground and the positive bridge terminal is connected to one end of an auto- transformer winding 59 having a magnetic core 60, and secondary winding 61.In the illustration, winding 59 functions as a voltage reducing auto-transformer with one of the lamp electrodes connected to respective mid taps 65 and 66 and the other lamp electrode connected to taps 67 and 68 located at the end of the winding. The purpose of the auto transformer is to match the DC power supply with the optimum voltage characteristic of the lamp. For example, the output of the diode bridge 53 is approximately 168 volts DC with 120 volt AC input. The optimumΪ E I OfΛPI & voltage for a 22 watt fluorescent lamp is, however, typically only 55 volts. Accordingly, the auto- transformer winding is selected so that the step down turns ratio is 168 divided by 55. It will be understood that if the optimum lamp operating voltage is larger than the DC power source voltage, • a step up auto transformer would advantageously be used to supply the stepped up voltage in the same manner.The collector of NPN switch transistor 14 is connected to the end terminal 68 of the auto- transformer winding 59. Its emitter is connected through a pair of diodes 69 and 70 and resistor 15 to ground. A capacitor 71 parallels the series connected diodes 69 and 70. Capacitor 71 is charge during steady state operation such that the combination of the capacitor 71 and diodes 69 and 70 back bias the transistor emitter.Integrated circuit 75, diode 76, resistor 77 and capacitor 78 comprise one shot multivibrator 18. The power supply for this one shot multivibrat is provided by the secondary winding 61, diode 44 and capacitor 45 as described above with reference to the circuit of Figure 5.The base of transistor switch 14 is connected to the output of the one shot multivibrator 18 through parallel connected resistor 80 and diode 81. Resistor 80 serves as a base current limiting resistor and shunting diode 81 serves to short out this resistor and provide a low impedance path for the charge stored in transistor 14 when the transistor is turned off. The base is also connected to ground through diode 82.Comparator amplifier 20 comprises transistor 85 whose emitter is connected to the junction of diode 70 and resistor 15 through, an RC filter comprising resistor 86 and capacitor 87. Its base is connected to potentiometer 23 and its collector 5 is connected to the input of one-shot multivibrator18 through resistor 88.Potentiometer 23 is connected in series circuit • with the resistor 90 and diodes 91, 92, 93, 94 and 95. ■ Resistor 90 reduces the sensitivity of ° potentiometer 23. Diodes 91 through 94 protect the circuit against transients when the on-off switch -19 is initially closed and diode 95 compensates for the base-emitter drop of comparator transistor 20. As in the embodiment of Figure 4, the reference 5 voltage for potentiometer 23 is provided by the output of secondary winding 61. The RC filter comprising resistor 86 and capacitor 87 serves to prevent a voltage or current transient from affecting comparator transistor 20 and inadvertently 0 triggering the one-shot multivibrator 18. A resistive path directly connecting the positive terminal of the diode bridge 53 to the power supply provided by secondary winding 61 is provided by resistor 100. This resistor serves as a current bleeder resistor to provide start up power when the on-off switch 19 is initially closed.Capacitor 105 and resistor 106 function in parallel with varistor 27 as a snubber protective circuit for protecting the transistor 14 from the ° inductive auto-transformer load when the transistor is being turned off.Another significant feature of the circuit of Figure 6 is the inclusion of thermistor 110 electrically connected between the input of one 5 shot multivibrator 18 and the positive side of the power supply capacitor 45. The thermistor is mechanically and thermally attached to the varistor 27 as indicated by the dotted line. The varistor has a negative temperature coefficient selected such that when a transient surge in the circuit causes the varistor to begin to overheat, the thermistor will become highly conductive and act to hold the input of the one shot multivibrator high, thereby maintaining the transistor 14 in the off state. Thus, the circuit illustrated in Figure 6 will remain effectively shut down until such time - as the varistor 27 has a chance to cool. Accordingly it will be seen that thermistor 48 prevents overheating of the varistor 27. An exemplary circuit for operation of a 22 watt fluorescent lamp from 120 volt AC power constructed in accordance with Figure 6 included the following circuit components:Transistor 14 MJE 13004 (Motoro Resistor 15 2.2 ohmPotentiometer 23 200 ohm Varistor 27 V27S 20 (General Electric) Resistor 52 1.5 ohm Diodes 54-57 IN 4003Capacitor 58 100 Micro faradWinding 59 - 263 + 6 + 150 + 6 turnsCore 60 Ferroxcube 376U25-3c8 and 376B250-3c8Winding 61 41 TurnsDiodes 69, 70, 76, 81, 82, 91-95 In4148Capacitor 71 10 Micro faradIntegrated Circuit 75 NE 555 VResistor 77 ■ 10K ohm Capacitor 78 .0033 Micro faradResistor 80 '■ 200 ohmTransistor 85 2N 3904Resistor 86 22 ohmCapacitor 87 .1 Micro faradResistor 90 1.3K ohmResistor 100 2OK ohmCapacitor 105 560 pico faradResistor 106 220 ohmThermistor 110 4C5002 (WesternThermistor) (B) High Power Factor Lamp CircuitThe circuit of Figure 6 may be used in those circumstances wherein the power factor of the entire lamp circuit is not critical. Thus, it will be understood by those skilled in the art that the wave smoothing capacitor 58, connected across the full-wave rectifier bridge 53, while being used to provide essentially a DC signal level to the circuit, nevertheless reduces the power factor of the circuit substantially. This is a result of the phase difference between the current and voltage at the terminals 50, 51 caused by the impdeance of capacitor 58. Such a power factor reduction is not permissible under certain circumstances.The second version of this invention, an embodiment of which is illustrated in Figure 7, provides a solution to this power factor problem. The circuit still operates from a 60-cycle alternating current source, but in this second version of the invention, the power factor is near unity. This is accompished by connecting the potentiometer 23 which, provides the reference signal level for the comparator 2Q through- a resistor 101 to the rectified AC voltage from the diode bridge 53. Thus, the circuit of Figure 7 is similar in operation to that of Figure 6, except that the reference voltage for the comparator/amplifier 20 is derived through the potentiometer 23 from a varying AC voltage rather than a fixed DC level, as was the case in Figure 6. This varying reference level provides, 'in accordance with- the waveforms ofFigure 3, a varying transistor switch current (Figure 3C) which is programmed, or fluctuates, in accordance with th-e 60 Hz input AC signal level. This fluctuati is shown in Figure 8A and the resulting line current drawn at the bridge 53 is as shown in Figure 8B, that is, the unrectified equivalent of Figure 8A. It will be seen from Figures 8A and 8B that the comparator 20 has been provided with a fluctuating threshold voltag which forces the current level through the resistor 15 to cyclically vary in a cycle which is precisely in phase with the applied voltage from the 60-cycle source. In each of Figures 8A and 8B, the average current 13 and 15, respectively, is shown for the resistor 15 and the input power terminals 50 and 51. This average current 13, 15 is precisely in phase wit the applied voltage, since the individual 20-40 kiloHertz peaks 17 and 19, respectively, of Figures 8A and 8B, have been programmed to be proportional to the applied voltage. Since the average current 15 is in phase with the applied voltage, the power factor of the circuit of Figure 7 is essentially unity. Thus, it has been found that, by using the circuit of Figure 7, the large wave smoothing capacitor 58 of Figure 6 may be eliminated from the circuit and the threshold voltage of the comparator 20 may be made to follow the 60-cycle AC line voltage by connecting the potentiometer 23 through a resistor 101 to the input rectified line source.The arrangement described improves the power factor of this lamp circuit so that it may be applied in most circumstances to standard AC line sources. It does, however, produce an additional problem not ■ present in the circuit of Figure 6. Specifically, it has been found that the resistance of the lamp 35 becomes very high each time that the applied AC line voltage at terminals 50,51 crosses zero volts.The relatively high resistance of the lamp.35 which is experienced at each zero crossing of the line voltage may be explained as follows. A gas discharge lamp 35 may be characterized as a resistor for frequencies whose period is small compared to the ionization time constant of the lamp. This is true for the ballast oscillation frequency of 20-40 kHz but not for the power line frequency 60 Hz. Thus, the ionization time constant of a 22-watt Circline fluorescent lamp, for example, is .4 milliseconds. Consequently, the effective resistance of the lamp will Vary during the 60-Hz line cycle. This resistance is greatest right after a zero axis crossing and decreases as the cycle progresses, reaching a minimum value approximately 60 electrical degrees before the next zero axis crossing.This high resistance of the lamp 35 causes the frequency of oscillation of the ballast circuit to decrease. Thus, while the normal frequency of oscillation is chosen to be above the audible range, the frequency may periodically drop down into the audible range after each line voltage zero axis crossing, which may prove annoying to persons near the lamp. In addition, and of more importance, is the fact that, after each zero axis crossing of the AC line voltage, an extremely high voltage will appear at the collector of the transistor 14, when the transistor 14 turns off. As was explained previously, if the lamp 35 is removed from the5 circuit, the collector of the transistor 14 is subjected to the extremely high fly back voltage o the ballast 17. This same affect occurs after eac zero crossing of the applied line voltage, since the effective resistance of the lamp 35 is very10 high. The repetitively applied high voltage at the collector of the transistor 14 may damage the transistor 14. Even if a protective clamping devi is employed, this device may itself overheat.The simplified circuit of Figure 9 provides a15 solution to this resistance problem without substantially degrading the circuit's power factor. The circuit of Figure 9 is similar in operation to that of Figure 6, except that it incorporates the 60 Hz input to the comparator/amplifier 20 describ20 in reference to Figure 7. In addition, a secondar winding 107 has been added to the inductor 17, thi winding being connected to a series combination of a diode 109 and capacitor 111. In addition, the junction between the diode 109 and the capacitor 125 is connected by a diode 113 to the output line 115 from the bridge 53. In addition, a filter circuit in the form of a series inductance 117 and shunt capacitor 119 is added between the line input terminals 50,51 of the full-wave rectifying bridge30 53.The capacitor 111 is relatively large, having enough capacity to maintain the lamp voltage durin zero axis crossing of the AC power line voltage at terminals 50,51. The turns ratio defined by the 5 secondary winding 107 is preferably less than one so that the voltage of the capacitor 111 is maintained at a lower value than the peak value of the line voltage on line 115.This circuit operates as follows. The secondary winding 107, capacitor 111, and the diode 109 form a positive DC power supply, charged periodically by the rectified voltage on line 115. This DC power • supply is only connected to supply power to the winding 59 when the AC line voltage on line 115 drops below 0 the voltage to which their capacitor 111 is charged. At this time, the capacitor 111 supplies current through the diode 113 to the lamp 35 inductor 17. - The diode bridge 53, during this same time period, disconnects the lamp 35 and inductor 17 from the AC power lines, since the diodes 51—57 within the bridge 53 are reversed biased. Thus, the line current drops to zero.The capacitor 111 continues to supply the ballast current until that point in the next half cycle when the line voltage on line 115 reaches the voltage level of the capacitor 111. At this time, the diode 113 becomes reversed biased, and the AC power line 115 supplies power to the lamp 35 and inductor 17. 5 The inductor 117 and capacitor 119 may be selected to filter out the 20-40 kHz variations of Figure 8B without substantially effecting the 60-Hz power factor.Figure 10 is a detailed schematic diagram of a•_> r, circuit similar to that of Figure 9, and including the circuit elements of Figure 6.Waveforms for the circuit of Figure 9 are shown in Figures 11A, 11B, and 11C, wherein Figure 11A is the applied AC line voltage at terminals 50 and 51, 3 showing the location of the zero crossing point,Figure 11B is the voltage at line 115 of Figure 8 showing that the voltage is the rectified equivalent of the yoltage of Figure 11A, except that the yoltage is held up or supported at a level 121 by the capacitor 113 at each zero crossing location. This, of course, prohibits a nulling at the lamp 35 so that the effective resistance of the lamp 35 never increases to a level which would generate excessive voltages at the transistor 14. Likewise, the voltage is maintained at a level which prohibits the lamp resistance 35 from lowering the frequency of the ballast circuit into the audible range.Figure 11C shows the line current drawn by the entire circuit at the AC line junctions 50 and 51. This current is filtered by the inductor 117 and capacitor 119 so that only the low frequency compone remain. From Figure 11C, it can be seen that no cur is drawn during those periods of time when the capacitor 111 supports the ballast current. In addition, Figure 11C shows small current pulses 123 which occur at the peaks of the AC line voltage and reflect the additional current utilized in charging the capacitor 111 at this time when the output of the transformer 107 exceeds the voltage of the capacitor 111. While it can be seen that the current waveform of Figure 11C is not a perfect sinusoid, it nevertheless is in phase with the voltage waveform of 11A and is sufficiently smooth and uniform so that the power factor is still near unity. The circuit of Figure 11 thus provides a high power factor lamp circuit which utilizes a small ballast and provides for a programmed current level for the lamp wherein each current peak at the 20-40 kHz rate is programmed to reach a level which is in a predetermined proportion of the line voltage determined by the potentiometer 23. At that same time, 'excessive voltages on the switching transistor 14 and reductions in the frequency of the entire circuit are eliminated through the use of the capacitor 111 which supports the line voltage level to prohibit a nulling of the rectified voltage.(C) Starter Aid CircuitFigure 12 illustrates a circuit similar to the circuit of Figure 6 but further including a starter aid 210. in the circuit of Figure 12, the fly back voltage across the electrodes 200, 201 caused by switching. the transistor 14 off must be sufficiently high to. light the lamp when the switch 19 is first closed.The voltage occurring in the circuit when the transistor 14 is first turned off, corresponding to time TR in Figure 2a, will be referred to as the fly back voltage. Ignition of the lamp requires that the fly back voltage between the two electrodes200, 201 in the lamp 35 be sufficiently high, and the distance between the electrodes 200, 201 be sufficiently small so that the resulting voltage gradient in the lamp 35 has sufficient magnitude to cause the gas inside the lamp 35 to ionize. The term voltage gradient is understood to be the voltage drop per unit distance. It is well known that, for a gas which may be used in a gas discharge lamp, there is a threshold voltage gradient below which ionization of the gas cannot be achieved. The voltage gradient near the electrode 201 at ignition of the lamp is proportional to the fly back voltage across the two electrodes 200, 201 divided by the distance between the electrodes 200,201. The large fly back voltages which are typically required may have deliterious effects upon the transistor 14, and therefore upon the reliability of the circuit of Figure 12. It is this concern for the reliability of the circuit of Figure 12 that prompts the use of varister 27, the thermister 110, and the capacitor 105.As mentioned above, it is well known that commercially available gas discharge lamps operate most efficiently at a certain optimum supply voltag In order to match the line voltage with this optimu lamp voltage, an auto transformer may be used as10 shown in Figure 12. The auto transformer 59 has a step down ratio which is proportional to the number of turns in the winding of the auto transformer 59 between the taps 66 and 67 divided by the total number of turns in the entire winding. 1 Introduction of the auto transformer 59 causes a reduction in the fly back voltage between the electrodes 200, 201. Therefore, in order to provid a threshold voltage gradient in the lamp 35 suffici to ignite the lamp when the switch 19 is first clos20 the fly back voltage must be increased. This increase in fly back voltage may be achieved by increasing the breakdown voltage of the varistor 27. Otherwise, when the switch 19 is closed, the lamp 35 may not ignite. This increase in fly back25 voltage, however, increases the likelihood of harm to the transistor 14 and decreases the reliability of the circuit of Figure 12.In the third version of this invention, these difficulties are overcome by connecting a starter30 aid 210, as shown in Figure 12 to ground 231, and locating the starter aid 210 adjacent the lamp 35. The starter aid 210 is merely an elongate conductor which is preferably mounted parallel to and within one inch of the lamp 35. It may, for example, be35 a thin strip of metal mounted on the outside of the lamp 35. The starting aid 21Q acts to increase the voltage gradient near the electrode 201 when the transistor 14 is first opened to produce a fly back voltage in the circuit. Because this fly back voltage is the largest voltage in the circuit, it is used to ignite the lamp. In the absence of the starter aid conductor 210, the voltage gradient created in the lamp by the fly back voltage is inversely proportional to the distance between the electrodes 200 and 201. However, when the starter- aid conductor 210 is connected to ground 231 and held adjacent to the lamp 35, it provides a voltage gradient between the electrode 201 and the starting aid conductor 210. This voltage gradient is much larger than the voltage gradient created in the absence of the starter aid conductor 210 between the electrode 201 and the electrode 200 because the distance between the electrode 201 and the starting aid conductor 210 is much less than the distance between the electrode 201 and the electrode 200.When the switch 19 is closed, the transistor 14 is first closed and then opens to cause the fly back voltage in the manner described earlier in this specification. The fly back voltage between the terminal 68 and ground 231 results in a large voltage gradient between the electrode 201 and the starter aid conductor 210. Of course, another voltage gradient will appear between the electrode 200' and the starter aid conductor 210, but because the fly back voltage at the electrode 200 is reduced by the step down transformer 59, the voltage gradient in the vicinity of the electrode 201 is larger.Preferably, the maximum voltage gradient which appears at the electrode 2Q1 is just sufficient to ionize the gas in the vicinity of the electrode 201 However, because this maximum yoltage gradient is restricted to a limited vicinity around the electro 201, ionization will occur in this limited area onl However, during subsequent operation of the circuit the vicinity of ionization will progressively expan • as best illustrated in Figure 14. Referring to Figure 3, assuming that the transistor 14 has opene to cause the fly back voltage at time T of Figure the transistor will again close at time T and the - fly back voltage will disappear. The transistor again opens at time T- a. and a fly back voltage again appears. The ionized gas which was created by the first fly back voltage at time T does not totally deionize between T and time T , the interval betwe fly back voltages, but substantially remains in the vicinity of the electrode 201, which is illustr in Figure 6 as the outlined region designated R O.During the next fly back voltage at T_, the ionized gas in the region Rfi acts substantially as a conductor. Therefore, a large voltage gradient is created by the fly back voltage at time T„ ____> and appears between the entire region RQ and the starte aid conductor 210. This large voltage gradient is sufficient to cause further ionization, and this causes the region of ionization to expand from the smaller region Rn to the larger region R^. Aga the cycle repeats itself, and this time the fly back voltage gradient appears between the conductin ionized gas in the expanded region R_ and the starter aid conductor 210, which causes the region of ionized gas to further expand until it encompass the region R .It is seen that, through successive cycles, th region of ionized gas expands progressively, . beginning in the smaller region RQ, then regions R^, R^, R^ and finally encompasses the region R„ which includes the second electrode 200 and establishes a conducting ionized gas electrical current path between the electrodes 200 and 201, at which time the ignition of the lamp 35 is complete. It may also • be seen that the fly back voltage of the terminal 68 required to ignite the lamp may be relatively small to increase the reliability of the circuit.It is significant that in the circuit of Figure 12, the location of the taps 65, 66, 67, and 68 on-the auto transformer 59 is arbitrary, and the electrodes 200,201 may be connected across any segment of the auto transformer 59 which gives the proper step down ratio without affecting the operation of the lamp 35 after ignition. For example, the lamp 35 may be connected across the top half of the auto transformer, or the lamp may be connected across the intermediate 0 segment of the auto transformer 59. However, as pointed above, the auto transformer 59 causes a reduction in the fly back voltage between the electrodes 200,201. A similar reduction in fly back voltage between the electrode 201 and ground 231, 5 which generates the starting voltage gradient between the electrode 201 and the starter aid conductor 210, is present in the circuit of Figure 12 due to the step down auto transformer 59. It is desirable to eliminate any reduction of the voltage between the electrode ° 201 and the conductor 210 by the auto transformer 59, so that the voltage gradient near the electrode 201 may be maximized when the transistor 14 first opens to create a fly back voltage to ignite the lamp 35.The circuit of Figure 13 eliminates any reduction 5 of the voltage gradient between the electrode 201 and the conductor 210 by the auto transformer 59. The operation of the circuit of Figure 13 is similar to that of Figure 12 except that the corresponding voltage gradient at the electrode 201 caused by th fly back voltage between the electrode 201 and the5 conductor 210 is maintained at the threshold level required for ignition without regard to the select of the step down ratio of the auto transformer 59. The electrode 201 in Figure 13 is connected direct to rhw terminal 68 connecting the transistor 14 to the auto transformer 59 while the other electrode is connected to a mid-tap on the auto transformer such as the mid-tap 66. Such a direct connection prevents the fly back voltage between the starter 210 and the electrode 201 from being reduced by th15 step down auto transformer 59.Unless the electrode 201 is connected to the collector of the transistor 14 as shown in Figure and the starter aid conductor 210 is used, the lar voltage gradient inside the lamp 35 at ignition is20 approximately proportional to the fly back voltage appearing across the terminal 68 and ground 231 reduced by the auto transformer 59 and divided by relatively large distance between the electrodes 2 200. It is now apparent that introduction of the25 starter aid conductor 210 permits a much smaller f back voltage to be used which can nevertheless cau a sufficiently large voltage gradient between the electrode 201 and the starter aid conductor 210 to achieve ionization of the gas in the lamp 35 and30 ignition of the lamp when the switch 19 is first closed. Furthermore, through proper connection of auto transformer to the lamp, as shown in Figure 1 an auto transformer of any step down ratio may be without affecting this voltage gradient. It shoul35 be recognized that a step up auto transformer for increasing the voltage supplied to the lamp 35 may also be used in place of the step down aut transformer 59 of Figure 13. (D) Symmetrical Lamp Voltage Regulation.The control circuits described above are particularly suited for use with low intensity, low pressure mercury vapor fluorescent lamps.However, -when used to control various other types of gas discharge lamps such as high pressure mercury•vapor, high or low pressure sodium, and metalHalide lamps, significant problems may arise. The efficiency of such lamps has been found to be maximized only when the lamp voltage waveform ofFigure 3D is symmetrical. |Referring to Figure 3D, it should be recognized that if the time interval between TQ and T is equal to the time interval between T A, and T oD, the voltage waveform supplied to the lamp, illustrated in Figure 3D, will have a generally symmetrical form. It has already been seen that the time interval between TΛ 0 and TA. is determined by-* the time delay of the one-shot multivibrator18 during which it remains in its low state before switching to its high output state. The time interval between T A, and T_B, is a function of the voltage supplied to the control circuit from the voltage source 16. Thus, if a symmetrical voltage waveform is to be supplied to the lamp 11, the voltage source 16 must supply a voltage having a magnitude which causes the time interval betweenT A,. and T a-,, illustrated in Figure 3D, to be equal to the fixed time interval between n and defined by the low output state of the multivibrator 18. If the lamp 11 in Figure 1 is a high intensity mercury vapor gas discharge lamp and a control circuit similar to the simplified circuit illustrated in Figure 1 is employed,. it has been found that a voltage supplied by the source 16 equal to 130 volts will cause a symmetrical voltage wavefo to be supplied to the lamp 11 in which the time interval between n and is equal to the time interval between T and T and the lamp voltage waveform as illustrated in Figure 3D.It is apparent that an obvious technique for providing a symmetrical voltage in the lamp 11 of Figure 1 is to' select a voltage source 16 which provides an output voltage of 130 volts DC. However as illustrated in Figure 3D, the symmetry or assymme' of the voltage waveform supplied to the lamp is not only a function of the magnitude of the voltage supplied by the source 16, but is also a function of the voltage supplied by the potentiometer 23 as a reference voltage to the comparator 20. Thus, even though the voltage from the source 16 will provide a symmetrical voltage waveform in the lamp 11 for one setting of the potentiometer 23, suc as setting Y of Figure 3D, changing the potentiome 23 to another setting, such as setting X of Figure 3D, will alter the lamp voltage waveform so that it is no longer symmetrical. Therefore, using this simplified technique, the symmetrical voltage waveform cannot be maintained if the setting of the potentiometer 23 is to be permitted to change.Another problem is encountered when the lamp 11 is a high intensity mercury vapor discharge lamp. If the voltage source 16 supplies the requisite 130 volts which results in the* control circuit providing a symmetrical voltage waveform in. the lamp 11, when the switch 19 is first closed and the lamp 11 is cold, the mercury vapor in the lamp 11 ionizes- very rapidly so as to cause the multivibrator 18 to change state to turn off. the transistor 14 prematurely before the current through the inductor17 has increased sufficiently. As a result, the warm-up period of the lamp 11 may be extended, and it is even possible that the lamp 11 and the associated control circuit will never reach the normal operating mode. This is a result of the fact that the voltage corresponding to a symmetrical waveform in the high pressure mercury vapor lamp, or symmetry voltage V , is 130 volts when the s lamp is warm but only 20 volts when the lamp is cold. Thus, the symmetry voltage changes as the lamp temperature changes during the entire time that the switch 19 is closed. Therefore, a single supply voltage from the source 16 will not always provide a symmetrical voltage waveform within the lamp. Furthermore, even if the magnitude of the voltage supplied by the source 16 is selected to equal the symmetry voltage of the lamp when warmed up, the lamp characteristics may change during the life of the lamp; or, if the lamp is itself exchanged for another lamp, the voltage supplied by the source 16 will no longer be the requisite symmetry voltage.If, on the other hand, symmetry is imposed by holding the on time of transistor 14 to a constant volue, for example, by use of a bi-stable multivibrator having fixed on and off time periods which are equal, it would no longer be possible to vary or select the lamp illumination intensity in the manner described above in connection with Figure 1. Figure 15 is a simplified schematic diagramIJU EALT_0MPI_ sΛ . iPO -* of an embodiment of. this invention in which the- foregoing problems are solved. A voltage regulator 300 supplies voltage to the gas discharge lamp 11 connected in parallel across an inductor 17. The parallel combination of the lamp 11 and inductor 17 is connected in series which a transistor 14 and a resistor 15 which is connected through ground to the voltage regulator return 330. A comparator amplifier 20 and an astable multivibrator 18 are connected between the transistor 14 and the resistor 15 in the same manner as discussed above in connection with Figures 1 and 3. The comparator 20 receives a reference signal from a reference voltage source 24 connected across a potentiometer 23. tThis invention includes the novel feature of a symmetry detector 355 having its input 360 connected to the collector of the transistor 14 and its output 365 connected- through an amplifier 370 and a stabilizing network 375 to a feedback reference input 380 of the voltage regulator 300. The symmetry detector 355, the amplifier 370, the stabilizing network 375, and the feedback reference input 380 form a supply voltage feedback control loop which maintains the supply voltage at the lamp 11 at the symmetry voltage V . The symmetry detector is a circuit that produces a DC voltage at its output 365 proportional to the difference between the on-time of the transistor 14, corresponding to the interval between T and T of Figure 3, and the off-time of the transistor 14, corresponding to the time interval between T and T of Figure 3. Therefore, in one embodiment the output 365 of the symmetry detector 355 is positive if the on-time of the transistor 14 exceeds its off-time while the output 365 of the symmetry detector 355 is negative if the on-time of the transistor 14 is less than its off-time.The stabilizing network 375 is included in the feedback loop to achieve stability against oscillation. It may be a simple low-pass filter including a resistor 385 and a capacitor 390. The operation of the feedback loop controls the output voltage V, of the voltage regulator 300 to be at or near the symmetry voltage V , which causes the on and off times of the transistor 14 to be equal, corresponding to a symmetrical voltage waveform to the lamp 11. A description of the operation of the feedback loop may begin with an assumption that the voltage V, supplied by the voltage regulator 300 to the lamp 11 is greater than the requisite symmetry voltageV , causing the on time to be shorter than the off time of transistor 14. This would cause the output 365 of the symmetry detector 355 to be negative. This negative output of the symmetry detector is amplified by the amplifier 370 and the resulting voltage is then applied to the feedback reference input 380 of the voltage regulator 300 as negative feedback. The voltage regulator 300 responds to this negative feedback by reducing voltage V, at the output 301 of the voltage regulator 300. For very high loop gains, the voltage supplied to the lamp 11 will be reduced by feedback from the symmetry detector 355 until it nearly equals V , at which time the output of the symmetry detector 355 will approach zero.At this point, a symmetrical voltage waveform will be applied to the lamp 11. It should be apparent that, while the symmetry voltage V may change due to temperature changes in the lamp 11 or due to aging of the lamp 11, the symmetry detector355 will cause the voltage supplied to the lamp to be maintained at or near the symmetry voltageVs, regardless of variations in Vs. The stabilizing network 375 prevents rapid changes in the feedback signal provided by the amplifier 370, thus increasin the stability of the supply voltage feedback control loop.The effect of the symmetry regulation loop of Figure 15 is best seen by reference to the time domain plots of the current through the choke 17 in Figure 16. Figures 16A and 16C are time domain plots of the choke current in the absence of symmetry regulation in a control circuit such as the circuit illustrated in Figure 1. The plots of Figure 16A and 16C are for two settings, X and Y , respectively, of the potentiometer 23 of Figure 1, and these plots are seen to correspond to the two time domain plots of Figure 3B. The effect of the introduction of symmetry regulation into the circuit is illustrated in Figure 16B and 16D. Figure 16B is a time domain plot of the symmetry regulated choke current for the setting X of the potentiometer 23 in the circuit of Figure 15 corresponding to the setting X of potentiometer 23 in Figure 1 and Figure 16D is a time domain plot of the symmetry regulated choke current for setting Y of potentiometer 23 in the circuit of Figure 15 corresponding to the setting Y of potentiometer 23 in Figure 1. Turning to the graph of Figure 16A and referring to the description of the circuit ofFigure 1, if the potentiometer 23 has a setting of X , the control circuit of Figure 1 will cause the time domain waveform of the choke current illustrated in Figure 16A to have a peak valueIvX. During3 the time interval from TO_. to T, , the choke current decreases as the flyback voltage in the choke 17 decreases. The time interval between T and T is a fixed interval determined by the duration of the astable state of the multi¬ vibrator 18. At time T, , the transistor 14 is turned on, the choke current increases until, at timeT a_., it reaches its peak value Ix--. At this time, the setting X of potentiometer 23 causes the circuit to flyback. If the supply voltage from the source 16 is of sufficient magnitude, the choke current will increase very rapidly, so that the time period from to T , required for the choke current to increase to its peak value, after the transistor 14 is turned back on, may be quite short with respect to the period from to of the astable state of the multivibrator 18. Therefore, in the absence of symmetry regulation, it is seen that the charging portion of the choke current waveform between TA.- and TB_ is much shorter than the flyback portion of the choke current between time Tn and a. This corresponds to an on-time of the transistor 14 which is much shorter than its off-time.If the symmetry regulated feedback control loop of Figure 15 is introduced into the lamp control circuit, as illustrated in Figure 15, the voltage V, supplied to the control circuit will be decreased by the symmetry control loop. As a result, after the transistor 14 s turned back on at time A, a much greater length of time is required for the current in the choke 17 to increase to its maximum peak value Iy determined by the setting X of potentiometer 23. The on-time of the transistor is increased as a result of the decrease in supply voltage, as illustrated in Figure 16B. Note that the slope of the top of the positive portion of the choke current waveform in Figure 16B is much more gradual than the corresponding portion in Figure 16A . This is a direct result of the decrease of the supply voltage V, impressed across the choke 17. The symmetry regulation feedback control loop of Figure 15 decreased the supply voltage V, from the voltage regulator 300 of Figure 15 to increase time TR to time TR, precisely so that(Tβl - TA) = ( A - TQ) . As a result, the corresponding symmetry regulated voltage waveform of Figure 16E is exactly symmetrical.If the setting of the potentiometer 23 of Figure 1 is changed from setting X to a higher setting Y , the peak current through the choke 17 will increase from I to I . The choke current will decrease during the time interval from T to to a value Iγγ/ as illustrated in Figure 16C. When the transistor 14 is turned back on at time T , the choke current will increase from I back to its maximum peak value Iγ determined by the setting Y of the potentiometer 23. If the voltage furnished by the source 16 in the absence of symmetry regulation is not very large, a long period of time corresponding to the interval T to T in Figure 166CC will be required for the current in the choke 17 to increase from I YY to Iγ. Therefore, the increasing portion of the choke current waveform of Figure 16C will last for a much longer period of time, T A. to T- a,, than the decreasing portion of the choke current waveform of Figure 16C as defined by the time interval T0~ to TA,. if the symmetry regulation control loop ofFigure 15 is now introduced into the control circuit as illustrated in Figure 15 while the potentiometer 23 has a setting of Y , the symmetry control loop of Figure 15 will cause the voltage supplied V, to the lamp circuit to increase. As a result, a shorter period of time will be required for the current through the inductor 17 to increase from I γ to I . This current increase occurs, as shown in Figure 16D, between time Ά and time T_, . Note that the slope of the top of the positive portion of the choke current waveform of Fibure 16D between time T A,. and T DD is much steeper than the corresponding portion of Figure 16C. This corresponds to the increase in the voltage V. impressed across the choke 17. With the increased setting Y of potentiometer 23, the introduction of the symmetry regulation control loop causes the time at which the lamp voltage reaches its peak value determined by the setting Y of potentiometer , 23 to decrease from time T--. in Figure 16C to time T_2 in Figure 16D. The symmetry regulation control loop causes the voltage supplied V, to the lamp control circuit from the voltage regulator 300, to be increased precisely so that the interval defined by T and T 2 equals the interval defined by T and T A, . As a result,' the on-time of the transistor14 equals its off-time and the lamp voltage waveform becomes symmetrical, as illustrated in Figure 16F. •Figure 17 shows a circuit similar to the circuit illustrated in Figure 15 but including, in addition, a reference voltage feedback control loop and a protective circuit to protect the transistor 14 in the event that the lamp is removed from the circuit. The reference voltage control loop minimizes variations in lamp intensity due to changes in supply voltage, and includes a divider circuit 400 having one of its inputs 405 connected to the output 301 of the voltage regulator 300 and its other input 410 connected to a variable reference voltage source 415. The output 420 is connected to a voltage limiter 425, which, in turn, is connected to one input of the comparator 20. Voltage Vτ -Li at the output 420 of the divider circuit 400 is proportional to the difference between reference voltage V_- of the reference source 415 and output voltage V, of the voltage regulator 301 connected to the inputs 410 and 4^05, respectively, of the divider 400.The divider 400 is shown in detail in Figure 18 as including a differential amplifier having its negative input 435 connected through a resistor 440 to the input 405 and also connected through resistor 445 to the input 410. The positive input 450 of the differential amplifier 430 is connected to the ground 325. Feedback resistor 455 provides scaling of the input voltages V and V, and the output voltage Vτ . The operation of the reference voltage'BΛJR.OMPI^RNAT feedback control loop (Fig. 17) is as follows: The variable reference voltage source 415 may be varied to select voltage V~ at the reference input of the comparator 20 so that the lamp 11 produces the illumination intensity desired by the user, as described above in connection with Figures 1, 2 and 3. If the output voltage V, of the voltage regulator 300 is reduced, the output voltage V of the divider 400 will be increased. This is because the voltage difference between the inputs 410 and 405- will have been increased due to the reduction in V« . The resulting increase in V will cause a corresponding increase in the voltage V? at the reference input to the comparator 20. As described above in connection with Figures 1, 2 and 3, the increase in V~ will cause a corresponding increase in the current flowing to the lamp 11. The resistors 440, 455, and 455 (Fig. 18) are selected so that the change in V_ precisely makes up for the change in V, to maintain the power supplied to the lamp 11 at a nearly constant value. The output voltage V_. of the regulator 300 may also increase after the reference voltage VD has been selected by the user. In this case, the difference between the voltages at the inputs 405 and 410 sensed by the divider circuit 400 will be smaller, which will result in a decrease in Vτ and a corresponding decrease in v at the input of the comparator 20. This will result in a decrease in current supplied to the lamp 11 in the manner described above in connection with Figures 1, 2 and 3.The voltage limiter 425 prevents excessive current from flowing through the lamp 11. It has already been pointed out that, if a high intensity mercury vapor lamp is used as the lamp 11, voltage initially applied to the lamp will cause it to ionize rapidly, causing an excessively large current to flow through the lamp while the lamp is still cold, which may damage the lamp 11. In order to prevent such an occurrence, the voltage limiter 425 clips the voltage Vτ supplied from the output 420 of the divider 400 to the reference input of the comparator 20. It has already been seen that the current rhough the lamp 11 is controlled by the voltage V supplied to the reference input of the comparator 20. Thus, the limiter 425 prevents excessive currents from flowing to the lamp.11 by limiting the value of the V~ • The voltage limiter 425 may, for example, be a zener diode 425A connected between the output 420 of the diviver 400 and ground. The voltage limiter 425 would thus clip the voltage V ± at the output 420 to a maximum value equal to the breakdown voltage of the diode 425A.When the gas discharge lamp 11 is in the warmed-up state and is momentarily extinguished due to power interruption, the voltage necessary to resta it is very large. Therefore, flyback voltage from the inductor.17 will cause the collector voltage on the transistor 14 to rise until the breakdown voltage rating of the transistor 14 is exceeded, causing damage to the transistor. In order to prevent damage to the transistor 14 in this manner, a protective circuit is provided which includes a metal oxide varistor 27 connected between the collector of the transistor 14 and input 465 of a comparator amplifier 470. Another input 475 of the comparator amplifier' 470 is connected to a reference voltage source 480, and output '.485 of the comparator amplifier 470 is connected to input 490 of an astable multivibrator 495. The .output 500 of the multivibrator 495 is connected to shut-down terminal 505 of the voltage regulator 300. If the flyback voltage of the inductor 17 0 exceeds the breakdown voltage of the varistor 27, the varistor 27 causes a current to flow through resistor 461, and thus a voltage to appear at the positive input 485 of the comparator 470. The voltage of the reference source 480 is selected to be less than the voltage at the input 465 which occurs at breakdown of the varistor 27. Therefore, the comparator amplifier 470 senses a positive difference between its positive input 465 and its negative input 475 and therefore causes a positive n υ signal to appear at its output 485 and at the input 490 of the one-shot multibibrator 495. This causes the multivibrator 495 to change state to produce a negative signal to appear at its output500 for a predetermined length of time. This 5 negative signal is conducted to the shut-down input 505 of the voltage regulator, which causes the voltage regulator 300 to turn off so that its output voltage V. goes to zero. At the end of the fixed time period of the multivibrator 495, the 0 multivibrator 495 changes to its stable output state, and consequently the voltage regulator 300 again supplies power to the lamp 11. This cycle will repeat itself if, for example, the lamp 11 is disconnected or fails to ignite. The breakdown 5 voltage of the varistor 27 is preferably selected to be less than the breakdown of the transistor 14, thus preventing damage to the transistor 14. This protective circuit is necessary because the voltage required to ignite the lamp 11 is much greater when the lamp is warm than when it is cold. Therefore, if the lamp is turned off, it is usually necessary to permit it to cool before reigniting. Thus, during the fixed time period set by the duration of the astable state of the multivibrator 495, during which the voltage regulato 300 is shut down, the lamp 11 is permitted to cool down. Thus, when the regulator 300 is again permitted to turn on, the lamp 11 will ignite and begin to conduct before the flyback voltage of the inductor 17 reaches the breakdown voltage of either the varistor 27 or the transistor 14. On the other hand, if the lamp 11 is either too hot or s not connected, the shut-down cycle of the protec¬ tive circuit will repeat itself.The voltage regulator 300 of Figure 17, include an AC current converter shown in block diagram form in Figure 19. Power is supplied to the current converter from a 60 Hertz current source to the inputs 600, 605 of the converter. A diode bridge 610 rectifies the €0 Hertz alternating current from a constant current source connected to inputs 610A, 610B- to produce a reactified 60 Hertz current at outputs 610C, 610D. As will be seen in the explanation that follows, the current converter, illustrated in Figure 19 regulates the power into a load 665 while presenting a purely resistive input impedance to 60 Hertz alternating current across the input terminals.600, 605. The current converter of Figure 19 includes a power oscillator comprising a choke 615, a capacitor 620, a transistor 625, a comparator amplifier 630, and a power amplifier 635. The inductance of the choke 615 and the capacitance of the capacitor 620 are preferably selected so that the power oscillator oscillates to switch the transistor at a frequency of approximately 20 kiloHertz.A sinusoidal 60 Hertz rectified current is produced at the output terminals 610C, 610D of the diode bridge 610. Current flows from output terminal 610D, charges capacitor 620, and flows through inductor 615. If the transistor 625 is on, the current flows from the inductor 615 to ground 640 where it returns through ground 645 and resistor 650 to the terminal 610C. If, on the other hand, the transistor 625 is off, the current flows through diode 655 and is divided between capacitor 660 and the load 665. The current returns from ground 670 to ground 645, through resistor 650, and back to the diode bridge terminal 610C. It may be seen that the proportion of the current flowing from the diode bridge terminal 610D through the load 665 is determined by the duty cycle of the transistor 625. Thus, the current converter controls the amount of current supplied to the. load 665 by controlling the duty cycle of the transistor 625.The base voltage of the transistor 625 is controlled by a comparator amplifier 630 through an inverting amplifier 635 connected to the base of the transistor 625. The negative input 675 of the comparator amplifier 630 is connected to the outputBITREAO PI fe/?NATlθg> terminal 610D through voltage divider resistors680, 685. The positive input 690 to the comparator amplifier 630 receives positive feedback from the output 695 of the comparator amplifier through voltage divider resistors 700, 705. The comparator amplifer 630 has a saturated output voltage which shall be denoted Vp. If the voltag^e VA, on the negative input 675 exceeds the voltage VD -D on the positive input 608, the comparator amplifier 630 wil saturate to its maximum negative output, -V by virtue of the positive feedback to the input 690.Thus, the voltage at the output 695 will be equal to -Vp. On the other hand, if the voltage VA_ at the negative input 675 is less than the voltageVR at the positive feedback input 690, the comparator amplifier 630 will saturate to maximum positive output so that the voltage at its output+ 695 will be +V . The output voltage -V of the comparator amplifier 630 is inverted and amplified by the amplifier 635 and applied to the base of the transistor 625. The positive feedback voltage applied to the positive input 690 is divided its most positive and most negative output voltages +V and -V , whenever the voltage V at the negative input 675 is equal to V (R705/(R700 + R7Q5)). If the power oscillator is to oscillate by switching the transistor 625 at a frequnecy of 20 kilohertz, the output of the comparator amplifier 630 at its output terminal 695 must switch back and forth between +V and -V at the same frequency. This in turn, requires that the voltage at the negative input terminal 675 must oscillate at a frequency of 20 kilohertz between +Vp (R_7-n05c /' (R_7_A0Λ0 +OMPI wipo and -V ( R705 ^R7 Q O + R705^ * Therefore , it is seen that the voltage at the negative input terminal675 averaged over one oscillation period must be zero. From this, it follows that the input impedance presented to the 60 Hertz current source across the input terminals 600, 605 is purely resistive, which shall be shown as follows.The current flowing through the diode bridge 615 between its terminals 610D and 610C shall^ be defined as I-N,. The value of the resistors 680,685 is preferably much larger than the value of the resistor 650 or the resistance of the load 665. Furthermore, the capacitor 620 is preferably selected so that it offers a very high impedance to the 60 Hertz rectified current flowing from the terminals 610D. Therefore, it is seen that voltageV , at the terminal 610C may be defined as follows:VC = R650 VIt has already been seen that the voltage supplied to the negative input terminal 675 averaged overa a 20 kilohertz oscillation cycle must be zero, and therefore voltage V-.-, at node 715 must be zero when averaged over an oscillation period. If the voltage at the output terminal610D is defined as V , it may be easily shown from the- foregoing that:VD = R650 IN<(R68θ/R685)+1)Defining the input voltage between the input terminals 600, 605 to be V.τ, it is seen that: From this it follows that:VN = ∑N R650 ((R680 R685} + 1 ] Recognzing the ratio of V^ to I-_ as the resistance between the terminals 600, 605, it is BJRt-Aϋ OMPI _. seen that the current converter of Figure 8 offers a purely resistive input impedance to the 60-Hertz current source connected to the input terminals 60 605, and that this reisstance is determined by the resistance of the resistors 650, 680, and 685. This feature is particularly advantageous in the voltage regulator 300 because it substantially eliminates the occurrence of reactive power losses typically present whenever reactive components, su as inductors or capacitors, change the phase of the current with respect to the voltage, resulting in inefficient use of the electrical power.From the foregoing, it may be easily shown that the power consumed by the voltage regulator300 incorporating the current converter of Figure is:2EN XN = ∑ R650 {(R680 R685} + 1] 'From this it is seen that the power consumed the current converter is independent of the resistance of the load 665, and thus the current converter of Figure 19 regulates the power consume > and prevents changes due to load resistance variations. Figure 20 illustrates various current and voltage waveforms in various points in the current converter near the diode bridge 610. The input current I supplied to the input terminals 600, 605 is illustrated in Figure 20A as a 60 Hertz sinusoid. In Figure 20B, the voltage at the terminal 610C, V , which has been seen to equal -I xR^..-.., is plotted as a rectified 60-Hert sinusoid of negative polarity. As discussed above, VD is equal to 2^ R65Q ( (R^/R^) +1), an - VD is plotted in Figure 20C as a 60-Hertz sinusoid of positive polarity. The current flowing from the terminal 610D to the terminal 610C is a function of I and is plotted in Figure 20D as a 60-Hertz rectified sinusoid of positive polarity. Figure 20E is a plot of V , as it appears across the inputs 600, 605. It is significant that the waveform of the plot of Figure 20E is in phase with the waveform of the plot of Figure 20A- because the input voltage and the input current are in phase with one another. This in-phase relationship is a result of the fact that input impedance presented by the current converter of Figure 19 to the 60-Hertz input current at the input terminals 600, 605 is purely resistive. This assures maximum efficient use of power by the current converter and prevents reactive power losses. A description of the operation of the power oscillator of the current converter of Figure 19 may begin with a current I flowing from the terminal 610D and a voltage V at the negative input 675 to comparator 630 which is greater than the positive feedback voltage V_ at the positive input terminal 690. The comparator 630 will sense a negative difference at its inputs and produce a negative output voltage -V ar its output 695. The amplifier 635 will invert the V output voltage to a positive voltage and this positive voltage will be applied to the base of the transistor 625. The transistor 625 responds to the positive voltage at its base- by turning on and conducting current to ground 640. Thus, the current I will flow through the transistor 625 to ground 640. This current returns through ground 645 through resistor 650 to the return terminal 610C. The capacitance of the capacitor 620 is preferably selected to operate a high impedance to the 60-Hertz current but provides some cmoothing to the 60-Hertz ripple in IM. Thus, the 60-Hertz I essentially does not flow through the capacitor 620. Because the transistor 625 has been turned on, the current I„ is permitted to bypass the resistance of the load 665, and is offered a lower resistance path directly through the resistor 650 and back to the return terminal 610C. As a result, the current through the inductor 615 increases, causing the capacitor 620 to discharge through the inductor 615 to contribute to the increased current drawn through the inductor 615. As a result, the potential across the resistor 720 decreases and becomes negati as the capacitor 620 discharges. Likewise, the voltage at the negative input 675 to the comparator decreases and becomes negative. The negative voltage at the input 675 will continue to increase in magnitude until it equals the negative voltage supplied through the feedback resistor 700 to the positive terminal 690, -V ^705 ^700+ R_nι.))» As soon as the comparator 630 senses that the voltage at its two inputs 675, 690 are equal, it switches to its most positive input voltage,+V . The positive output voltage V is inverted and amplified by the amplifier 635 and applied to th base of the transistor 625. The resulting negative voltage causes the transistor 625 to turn off, thereby forcing the current through the inductor 615 to be divided between the capacitor 660 and the load 665. !BUR O At this point, the current flowing from the terminal 61OD through the inductor 615 is now presented with a higher resistance, and it therefore begins to decrease over a period of time at a rate controlled by the inductance of the inductor 615. As a result of this decrease in current, the capacitor 620 •no longer discharges but instead begins to be charged by current flowing from the terminal 610D. As a result, the voltage across the capacitor 620 begins to increase. This causes an increase in - voltage across the resistor 720 and an increase in the voltage V at the terminal 610D. The voltage V at the -negative input 675 of the comparator 630 begins to increase, and continues to increase until it equals the voltage VR at the positive feedback terminal 690. As soon as the voltage at the negative input 675 has increased to equal the voltage at the positive feedback input 690, the comparator 630 changes state so that its output saturates to -V , and the entireP cycle repeats itself. The comparator 630 switches its output between +V • and -V at a frequency of approximately 20 kilohertz, which is a frequency controlled by the inductance of the inductor 615 and the capacitance of the capacitor 620. The frequency of the oscillation, while preferably near 20KHz, is also proportional to the 60Hertz input current IN flowing from the terminal 610D. Thus, the power oscillator will oscillate in the above-described manner at a frequency slightly less than 20 KHz when the 60 Hertz currentI,Nτ nears its minimum value and will oscillate at a frequency somewhat greater than 20KHz when IfjURtAtT O PI reaches its peak value. Thus, the oscillation frequency of the power oscillator is slightly modulated by the 60 Hertz line frequency cycle. Figure 21A is the same plot as Figure 20A except that the time scale is greatly expanded so that the 60 Hertz sinusoid appears to be a straight line. Figure 21B illustrates the voltage across the transistor 625. The waveform of the transistor voltage is a nearly square wave having a frequency of 20 kilohertz corresponding to the frequency of the power oscillator. Figure 21C illustrates three plots. The jlot labeled 72_, Fig. 21C, is a plot of the voltage across the resistor 720 as a function of time. This clearly shows that when the transistor is turned on at time T_, the current discharging through the capacitor 620 causes the voltage V__n across the resistor 720 to decrease and become more negative until the comparator 630 switches at time T, . At time T. , the transistor is turned off, and the capacitor 620 begins to charge, causing the voltage V720 across the resistor 720 to increase until it becomes positive. As is apparent in Figure 21C, the voltage V--^ increases until the comparator 630 switches back to its negative output state. As previously discussed, the capacitance of the capacitor 620 is preferably selected so that variations in voltage across the capacitor are minimal and the capacitor offers insignificant impedance to the 20 KiloHertz oscillating current. Accordingly, in Figure 21C, the plot of the voltage across the capacitor, labeled V,---., appears as a straight line. Another plot in Figure 21C is labeled V , the voltage at the output 610D. V is the sum of the voltage across the capacitor, Vf-2Q Plus the voltage across the resistorV__n and is superimposed on the two plots, V7-n5 and V _. in Figure 21C.The plot of Figure 21D illustrates the voltageVA at the negative input to the comparator 630 and the voltage V_ a at the positive terminal 690 of the comparator 630. VR alternates between -V 0 ( R705ΛR700 + R705)) and +Vp(R705/(R700+R705) } 'V must oscillate between these same two limits. Figure 21D clearly shows that the comparator630 changes state only when V A.. = V_is, which occurs alternately at the upper and lower peak voltages 5 of V B_. This,r it is ap trptrarent t;hat VA_- is constrained to the upper and lower limits of V_. It may be easily shown that the positive and negative peak values of the voltage V7~Q are plotted in Figure 21C are constrained to + —Vp ( R-/-Ur.-./(R_/UΛU_ + R_/UΛb_)) 0 ((R680 + ^SS^SS* 'Thus, the magnitude of the oscillation of the power oscillator is controlled by the maximum voltage output V of the comparator 630. The resulting current waveforms are illustrated in 5 Figure 2IE. The plot labeled in Figure 21E as ,-Ig~20 is defined as the current through the capacitor 620. As already discussed, the capacitor 620 presents a very high impedance to the 60 Hertz input current I„ but presents a very low impedance to the 20 kilohertz oscillating current. Therefore, the current I£20 through the capacitor 620 oscillates at a frequency of 20 kilohertz about zero. The current I,, _ through the choke 615 is equal to the difference between the input current I„ D flowing through the output terminal 610D aNnd the current lg2o fl°win9 through the capacitor 620. Therefore, the plot labeled Igl5 in Figure 21E may be derived by subtracting the plot of in Figure 2IE from the plot of the current I5 in Figure 21A. Figure 21E shows that while the current I,,, to the inductor 615 is always positiv the 20 kHz oscillation in I 6,115C causes the currentI -n through the capacitor 620 to oscillate about zero current.10 Figure 21F is a plot of the current through the transistor 625, and it is seen that during the time that the transistor 625 is turned on, between time n and T, , the current through the transistor 625 follows the current Iβ1-. through the inductor15 615 plotted in Figure 2IE.. The current through th diode 655 is plotted in Figure 21G and it is seen that the current through the diode 655 follows the current I-.,(_ through the inductor 615 while the transistor 625 is turned off. The current20 through the diode 655 is divided between the load665 and the capacitor 660. Because the relationshiEΛ = J 2 R450 (( R480/R485 } + 1) WaS estabHshe supra, defining the input power, and because it ca be shown that the losses in inductor 415,25 transistor 425 and diode 455 are small, and relatively constant, it follows that the output power is constant and the output current I, and voltage V, may be controlled by controlling the resistance of Rb,-0o1-. In fact, the resistance Of may be varied in a feedback control loop designed to control the output current or voltage of the current converter of Figure 19. Such a concept is illustrated in Figure 22.In Figure 22, the resistor 685 is replaced instead by a field effect transistor 740. In the exemplary embodiment of Figure 22, the transistor 740 is an N-channel field effect transistor. The feedback control loop consists of a differential amplifier 745 having its negative input 750 connected to output 755 of the current converter of Figure 19. Positive input 760 of the amplifier 745 is connected to a reference voltage V . The output 770 of the amplifier 745 is connected to the gate of the field effect transistor 740. The current converter of Figure 19 together with this feedback loop comprise the voltage regulator 300 of Figure 15. The feedback' loop, including the amplifier 745 acts as a supply voltage feedback control loop and controls the output voltage V, at the output of the voltage regulator of Figure 22. The operation of the feedback loop is as follows.If V, exceeds V_, the amplifier 745 will sense a negative difference between its inputs 750, 760 and will produce a negative voltage at its output 770 proportional to the difference between Vg and V, . This negative voltage is applied to the gate of the field effect transistor 740, which causes the resistance of the transistor 740 to increase. This is equivalent to an increase in the resistance of Rj-oc in Figure 19. The peak value of lgτς being inversely proportional to fioc:' will be decreased. Likewise, if the output voltage V1 is less thanVc, the amplifier 745 will sense a positive differe between its inputs and apply a positive voltage to the gate of the field effect transistor 740, thereby causing a decrease in the resistance of.the field effect transistor 740. This will cause a consequent increase in the power delivered to the load 465.. It has already been seen that this power varies according to the ratio of 1/Rg8-.. Variation in the resistance of the field effect transistor740 are equivalent to the variation in the r-sistan of Rgoς* Thus, it is seen that the output power an consequently the voltage V 1 supplied to the load 665 are readily controlled by controlling the resistance of the field effect transistor 740 in the supply voltage feedback control loop.A high frequency symmetry regulated lamp control circuit illustrated in Figure 24 has been built to include the foregoing featues, and Figure 23 is a simplified block diagram of that circuit. Essentially, the circuit of Figure 23 includes the circuit illustrated in the block diagram of Figure 17 in which the voltage regulator of Figure 22 is used as the voltage regulator 300 of Figure 17.Thus, the circuit of Figure 23 is a combination of -the circuits illustrated in Figures 15 and 22, and includes, in addition, an over-voltage detector 800 which protects the electrolytic capacitor 600, and a 6 volt DC power supply 805 to operate the electronics in the various components of the circui in the block diagram of Figure 22.BU A OMPI sfa, WIPO In Figure 23, the supply yoltage feedback control loop includes a symmetry detector 355 having its input 355a connected to the collector of transistor 14 and its output 355b connected to the gate of the field effect transistor 740. As discussed above, in connection with Figures 19 and 22, the field effect transistor 740 replaces the resistor 685 of Figure 19 to provide variable control over the value of the output voltage V, . ■ It will be remembered that the value of V-, is controlled by the ratio(R680 + R685) / R685* The Value of R685 is controlled by changing the resistance of the transistor740. The details of the symmetry detector 155 are best seen by reference to Figure 13. Figure 13 shows that the symmetry detector 155 includes an amplifier circuit 610 having its input 610a connected to the collector of the transistor 14. Output 610a of the amplifier circuit 610 is connected through resistor 615 to resistor and capacitor pairs 620, 625 and 630, 635. Both capacitor resistor pairs, 620, 625, and 630, 635 are connected between ground 640 and the positive input to amplifier 645. The output of amplifier 645 is connected across capacitor 650 to the gate of the field effect transistor 540.The amplifier circuit 810 produces an output voltage of plus 6 volts at its output 810b whenever the transistor 14 is off, and produces an output voltage of minus 6 volts at its output 810b whenever the transistor 14 is on. The current flowing from the output 810b charges the capacitors 825, 835 to a positive or negative voltage depending upon the polarity of the voltage at the output 810b. It follows that the magnitude and. polarity of the voltage on the capacitors 825, 835 is determined by the difference between the off. time of the transistor 14 and its on time. Thus, if the on time of the transistor 14 is greater than its off time, the voltage across the capacitors 825, 835 will be negative, since a negative charge will be accumulated at the ungrounded plates of the • capacitors 825, 835. On the other hand, if the off time of the transistor 14 exceeds its on time,10 a net positive charge will be accumulated at the ungrounded plates of the capacitor 825, 835, and a- positive voltage will appear across these capacitor The voltage appearing across the capacitors 826, 835 is amplified and scaled by the amplifier 845. 15 The output of the amplifier 845 is applied across the capacitor 850 to the gate of the field effect transistor 740. If the off time of the transistor 14 exceeds its on time, it is seen that the output of the amplifier 845 will be positive, and will20 cause the voltage across the capacitor 850 to increase to a higher positive value. The transisto 740 in the embodiment of Figure 24 is preferably a P-channel field effect transistor. Therefore, the increasingly positive voltage across the capacitor25 850, which is applied to the gate of the transistor 740 causes the resistance of the transistor 740 to increase. As discussed above, the output voltage V, of the voltage regulator 300 is controlled by the resistance of the transistor 740, and therefore30 V, will decrease. The on time of the transistor 14 will begin to increase, causing a corresponding decrease in the positive voltage across the capacitors 825, 835 and a corresponding decrease in the positive output voltage of the amplifier 845.35 Thus, the rate at which the capacitor 850 is charge slowly decreases until the on time of the transisto 14 is nearly equal to its off time. At this point, the net charge accumulated on the capacitors 825, 835 is almost zero. Thus, the amplifier 845 no longer increases the voltage across the capacitor 850 and therefore the voltage applied to the gate of the transistor 740 becomes constant. This stabilizes the transistor 740 and stabilizes the output voltage V, of the voltage regulator 300. At this point, V, equals V , the symmetry voltage of the lamp.Conversely, if the on time of the transistor - 14 is greater than its off time, a negative voltage will begin to appear across the capacitor .825, 835, causing the output from the amplifier 845 to become negative. Thus, the amplifier 845 begins to decrease the voltage across the capacitor 850 and continues to do so until the resistance of the transistor 745 has increased sufficiently to cause the output voltage V-, of the voltage regulator 300 to decrease, causing a corresponding increase in the on time of the transistor 14. The feedback loop is stabilized as soon as the on time has increased to equal the off time of the transistor 14. At this point, the net voltage across the capacitor 825, 835, is null, and, as a result, the amplifier 845 no longer reduces the charge on the capacitor 850. Thus, the voltage at the gate of the transistor 740 and the corresponding resistance of the transistor 740 is stabilized corresponding to a stabilized value of the output voltage V-. which is equal to the symmetry voltage V of the lamp.A shut-down circuit is illustrated in the detailed schematic in Figure 24 and includes a comparator circuit 900, a reference voltage source 901, a varistor 902, a multivibrator circuit 903 connected to amplifier circuit 635, and is somewhat different from the shut-down circuit discussed above in connection with Figure 17. As discussed above in connection with Figures 19 and 22, the 5 output of the comparator 630 is conditioned by the amplifier circuit 635 to control the transistor 625. As discussed above in connection with Figure 17, the shut-down circuit operates to shut-down the output of the voltage regulator 300. The10 shut-down circuitry of Figure 24 is shown in simplified block diagram form in Figure 25. The varistor 902 is connected between the collector of- the transistor 14 and the input to the multivibrat circuit 903. The output of the multivibrator circ15 903 is connected to the amplifier 635. Another in to the multivibrator circuit 903 is controlled by the output of the comparator 900. One input of th comparator amplifier 900 is connected to the outpu 755 of the voltage regulator 300. The other input20 to the comparator amplifier 900 is connected to th reference voltage source 901. The shut-down circuit illustrated in Figure 14 will null the out voltage V-, at the output 755 of the voltage regulator 300 'for a duration of predetermined leng25 if either the output voltage V-, of the voltage regulator 300 exceeds a magnitude defined by. the reference voltage source 901 or if the collector voltage of the transistor 14 exceeds the breakdown voltage of the varistor 902. The operation of the30 shut-down circuit is as follows. The comparator amplifier 900 produces a voltage output which is proportional to the voltage difference between its two inputs. If the output voltage V-, of the voltage regulator 300 exceeds the magnitude define35 by the reference voltage source 901, the comparato amplifier 900 will output a positive voltage to th input of the multivibrator circuit 903. The:^RE multivibrator circuit 903 will respond by changing state to produce an output signal to the amplifier 635 which causes the ampli er 635 to hold the voltage at the base of the transistor 625 to a positive value in order to hold the transistor 625 on. At the end of a predetermined length of time, • the multivibrator returns to its original state, so that the amplifier 635 no longer holds the transistor 625 in its on state. While the transistor 625 is held in its on state, all the current flowing through the inductor 615 is returned to ground through the transistor 625, thereby causing the output voltage -V, of the voltage regulator 300 to drop to zero. Thus, the output voltage is nulled during the predetermined length of time defined by the astable state of the multivibrator circuit 903. Similarly, if the collector voltage of the transistor 14 exceeds the breakdown voltage of the varistor 902, the varistor 902 will break down causing this voltage to appear at the input to the multivibrator circuit 903. Again, the multivibrator circuit 903 will switch to its astable state and cause the output voltage V, to be zero for a predetermined length of time in the same manner. The comparator amplifier 900 prevents the output voltage V, from exceeding the capacity of the capacitor 660, thereby protecting the capacitor 660. This is an important feature because the capacitor 660 is preferably a large electrolytic capacitor which smooths the output voltage V-, of the voltage regulator 300. The** varistor 902 prevents the collector voltage on the transistor 14 from exceeding the breakdown voltage of the transistor. Preferably, the breakdown voltage to the varistor 902 is less than the breakdown voltage to the transistor 14. This feature is useful because, if the lamp 11 were to be monetarily disconnected then reconnected, the re-ignition voltage of the warm lamp 11 would 5 exceed the breakdown voltage of the transistor 14. The shut-down circuit of Figure 25 causes the voltage regulator 300 to turn off before the . collector voltage can damage the transistor 14. It shuts the voltage regulator 300 off for the10 predetermined length of time defined by the multivibrator circuit 903 during which the lamp 11 has an opportunity to cool. When the lamp 11 . has sufficiently cooled, its re-ignition voltage i less than the breakdown voltage of the transistor15 14, and the voltage regulator 300 may then be turned back on. The shut-down circuit may cycle several times while the lamp 11 has a chance to cool sufficiently.While Figure 24 illustrates the currently20 preferred embodiment of the invention, it should be recognized that the invention may be implemente in a number of different ways to provide a symmetr regulated voltage source. For example, in the embodiment of Figure 24 the field effect transisto25 740 is a p-channel FET, whereas, if the output of the symmetry detector 355 is inverted, the transistor 740 may be an N-channel FET.3035 E. CAPACITIVE DISCHARGE IGNITION CIRCUIT AND CONSTANT- POWER REGULATION The control circuit of Figure 1 is particularly suited for use with low intensity, low pressure mercury vapor fluorescent lamps. However, when used to control various other types of gas discharge lamps such as high pressure mercury vapor , high or low pressure sodium, and metal Halide lamps, significant problems may arise.One problem with the lamp control circuit of Figure 1 is that, if the lamp voltage illustrated in' Figure 3D during the flyback mode of the circuit from TQ to is of insufficient magnitude to ignite lamp 11 'when the switch 19 is first closed, then other means must be provided to furnish a sufficiently high voltage to ignite the lamp when the circuit is first activated. A typical high intensity discharge lamp such as a 400-watt high pressure sodium lamp, requires approximately 2500 volts across the lamp in order to ignite the lamp. One solution may be found by looking to prior art fluorescent lamp ballasts which operate at 60-Hertz and which must of necessity use very large and heavy inductors. In these prior art ballast circuits, the common technique for igniting the fluorescent lamp is to connect the secondary winding of a step-up transformer in series with the lamp, and connect the primary winding to a capacitive discharge device. Such a scheme presents insignificant problems in these prior art heavy ballast circuits because the additional inductance of the secondary winding is small compared to the inductance already present in the ballast. Furthermore, these prior art 60-Hertz ballast circuits do not fly back, as does the 20-kHz lamp circuit of this invention. As will be seen in a later portion of this description, the flybac cycle of the lamp control circuit of this inventio creates special problems when the step-up5 transformer is introduced.Figure 26 illustrates a circuit which provide the ignition voltage of 2500 volts in a lamp contr circuit similar to the control circuit as illustrated in Figure 1 but using a high voltage10 ignition circuit similar to that used with prior art lamp ballast circuits. The high voltage ignition circuit includes a step-up transformer 950 having a primary winding 951 and a secondary winding 952. The secondary winding 952 is15 connected in series with the gas discharge lamp11 while the primary winding 951 is connected to a pulse voltage source 953, which may, for example, a capacitive discharge device. Control circuit 949 of Figure 26 includes the control components of20 Figure 1 including the multivibrator 18, the comparator amplifier 20, the potentiometer 23, and the reference voltage source 24.The pulse transformer 950 has a step-up ratio which is sufficient to provide 2500 volts to25 the lamp 11. Thus, when it is desired to ignite the lamp 11, the capacitive discharge device 953 provides a high voltage pulse to the primary windi 951, which is stepped up by the pulse transformer 950 to approximately 2500 volts across the seconda30 winding 952. This 2500 volts appears across the lamp 11, and causes the gas inside the lamp 11 to begin to ionize. If the first voltage pulse from the capacitive discharge device 953 is insufficien to completely ignite the lamp, the process will be35 repeated until ionization in the lamp is complete the lamp 11 begins to conduct. At this point, the remainder of the control circuit may begin to func as described above in connection with Figures 1, 2 , and 3.Unfortunately, the control circuit of Figure 26 has the disadvantage that, after the lamp 11 has ignited, current through the lamp 11 will cause a current to be induced through the primary winding 951 having a large magnitude corresponding to the large step-up ratio of the transformer 950. As a result, a significant power loss will occur through the transformer 950. This will decrease the efficiency of the control circuit of Figure 26 significantly. A solution to this problem is to provide a switch 954 which may be opened to prevent current from flowing through the primary winding 951. However, after the switch 954 has been opened, the secondary winding 952 now acts as a large inductor in series with the lamp in addition to the inductor 17. At this point, the undesirability of applying the starting circuit used in prior art 60-Hertz lamp ballast circuits to the high frequency switching circuit of Figure 1 is apparent. One significant feature of the high frequency switching circuit of Figure 1 is that the circuit flies back at a frequency of 20-kiloHertz , and as a result the inductance of the inductor 17 may be very small in comparison with the large inductors typically used in prior art 60-Hertz lamp ballast circuits. Because the lamp ballast circuits of the prior art typically ■ ■ have large inductors, introduction of the secondary winding of the step-up transformer of the ignition circuit did not represent a significant increase in the inductance of the circuit, and therefore, introduction of the high voltage ignition circuit into the prior art ballast circuits did not change the operation of these circuits significantly. In contrast, the addition of the secondary winding 952 to the 20-kiloHertz lamp control circuit of Figure 26 represents a significant increase in the5 inductance in the circuit because the inductor 17 is relatively small. Furthermore, unlike the 60-Hertz ballast circuits of the prior art, the 20-kiloHertz control circuit of Figure 1 flies back each 20-kiloHertz cycle. This creates10 special problems in introducing the step-up transformer 950 in series with the lamp 11 which are peculiar to the 20-kiloHertz control circuit of Figure 26, and which were not encountered with the prior art 60-Hertz ballast15 circuits. During the flyback cycle of the20-kiloHertz control circuit of Figure 26, when the transistor 14 is turned off, the flyback voltage of the inductor 17 must cause a reversal of the direction of the current in the lamp 11. The magne20 field in the secondary winding 952 opposes the current flowing through the lamp 11 during this flyback cycle, thereby increasing the impedance to the current flowing through the lamp 11, thus reducing the efficiency of the control circuit of25 Figure 26. Furthermore, the inductance of the secondary winding 952 represents a significant increase in the total inductance of the control circuit of Figure 26, which corresponds to a significant increase in the flyback voltage30 impressed across the transistor 14 and the varistor 27. This increase in flyback voltage causes the varistor 27 to conduct more current to ground durin the flyback cycle of the circuit of Figure 26, representing a further loss in efficiency of this35 circuit of Figure 26. Thus, it is apparent that introduction of the high voltage ignition circuit used in prior art 60-Hertz ballast circuits into the 20-kiloHertz lamp control circuit of Figure 1, as illustrated in Figure 26, significantly reduces the efficiency of the 20-kiloHertz lamp control circuit. The circuit of Figure 27 illustrates an embodiment of the invention in which the foregoing problems are solved. The control circuit of Figure 27 includes a lamp control circuit similar to the lamp control circuit of Figure 1, and further includes a pulse transformer 950 having its primary winding 951 connected across a pulse voltage source 953 such as a capacitive discharge device and a secondary winding 952 connected in series with the lamp 11. In addition, the circuit includes a rectifying diode 955 connected across the secondary winding 952, and a control circuit 956.The diode 955 may be any rectifying means, and has its polarity disposed so as to permit current flowing from the inductor 17 to the lamp 11 when the transistor 14 is turned off to flow through the diode 955 and bypass the secondary winding 952 and provides an alternate path for current flowing in the secondary winding 952 during the flyback cycle. The diode 955 maintains a substantially constant current through the secondary winding 952 so that the winding 952 does not present any substantial impedance or energy loss during the charging cycle of the circuit. This feature substantially prevents the inductance of the secondary winding 952 from affecting the operation of the lamp control circuit during its normal operating mode after the lamp 11 has been ignited.A control circuit 956 controls the operation of the pulsed voltage source 953. The control circuit 956 has one of its inputs 956a sensing the collector voltage on the transistor 14, while its other input 956b senses the output from the control circuit 949 to the base of the transistor 14.5 Operation of the circuit of Figure 27 is as follows. When the circuit is first activated and the lamp 11 is to be ignited, a large flyback voltage appears across the transistor 14 as discussed above in connection with Figures 1, 2,10 and 3. Input 956a and the control circuit 956 sense that the lamp 11 is off by sensing this large collector voltage, which means that the voltage sou 953 must be activated to ignite the lamp. The control circuit 956 will activate the pulse voltage15 source 953 only after the transistor 14 is turned back on, in order to prevent the large ignition voltage from the pulse transformer 950 from imposin a large collector voltage on the transistor 14. When the transistor 14 is on, this is sensed at the20 input 956b of the control circuit 956 by sensing the output voltage of the control circuit 949 to th base of the transistor 14. At this time, the contr circuit 956 causes the pulsed voltage source 953 to impose a voltage in the primary winding 951, which25 of sufficient magnitude to cause an ignition voltag of 2500 volts on the secondary winding 952. This ignition voltage causes the gas 'in the lamp 11 to begin ionization. If this ionization is not comple then during the next cycle of the lamp control circ30 the control circuit 956 will again sense that the l is still nonconducting by a high collector voltage of the transistor 14 sensed at input 956a. Again, soon as the base voltage of the transistor 14, sensed by input 956b, indicates that the transistor35 1 is on, the control circuit 956 will reactivate the pulsed voltage source 953 causing the pulse transformer 950 to produce a 2500-volt ignition pulse for a duration determined by the pulsed voltage source 953. This cycle will repeat itself until the lamp 11 has ionized sufficiently to permit a normal driving of the lamp 11 with only the driving circuit 949.This circuit has the advantage that, after the lamp 11 is ignited, the inductance of the secondary winding 952 does not affect the operation of the lamp control circuit. The operation of the circuit of Figure 27 when the lamp 11 is ignited is as follows: After ignition of the lamp 11, the control circuit of Figure 27 assumes its normal oprating mode similar to that described above in connection with Figures 1 and 2, and the secondary winding 952 effectively becomes an inductor, as the control circuit 956 opens the primary winding 951 to effectively take it out of the circuit. During the charging portion of the 20-kiloHertz cycle of the control circuit of Figure 27, when the transistor 14 is on, current flows from the power supply 16 and is divided between the inductor 17 and the lamp 11. Part of the current flows through the inductor 17 and the transistor 14 to ground, while the remaining current flows through the lamp 11, the secondary winding 952, and the transistor 14 to ground. During this charging cycle, the current through the transistor 14 will increase as the magnetic fields in the inductor 17 and the secondary winding 952 increase. During the flyback portion of the 20-kiloHertz cycle of the control circuit of Figure 27, when the transistor 14 is off, the current flowing through the inductor 17 flows through the diode 955 and the lamp 11, thereby completely bypassing the secondary winding 952. As a result, the magnetic field in the secondary winding 952 cannot oppose the current flowing through the lamp 11 during the flyback cycle. Furthermore, the diode the current flowing in the secondary winding 952, thereby preventing this current from affectin the operation of the control circuit of Figure 27. 5 As a result, the current through the secondary winding 952 does not significantly decrease during the flyback cycle. Therefore, when the transistor 14 is again turned back on, the current supplied from the power source 16 flowing through the lamp10 11 is not required to significantly change the current flowing through the secondary winding 952. As a result, current in the secondary winding remai fairly constant and the secondary winding 952 does' not present a significant impedance to the current15 flowing through the lamp 11 during the charging portion of the 20-kiloHertz cycle. Therefore, the secondary winding 952 does not absorb significa power from the power source 16.It is now apparent that the shunting diode 95520 prevents the inductance of the secondary winding 95 from affecting operation of the control circuit of Figure 27 during either the charging portion or the flyback portion of the 20-kiloHertz cycle. Furthermore, because the diode 955 shunts the curre25 across the secondary winding 952 during the flyback cycle, the inductance of the secondary winding 952 does not contribute to the flyback voltage across the transistor 14. Instead, only the inductor 17 contributes to the flyback voltage across the30 collector of the transistor 14, as in the circuit of Figure 1, even though the circuit of Figure 27 includes the pulse transformer 950 in series with t lamp 11 having a very high step-up ratio. This invention thus includes a source producing a high35 ignition voltage across the lamp 11 which does not increase the flyback voltage in the lamp control circuit. Another problem inherent in the control circuit of Figure 1 is that the power consumed by the circuit is dependent upon .the effective resistance of the gas discharge lamp 11. It is well known that if the control circuit oscillates at a high frequency, the lamp 11 may be characterized as a resistor. For high pressure mercury vapor lamps, this equivalent resistance is relatively' constant over the life of the lamp. The problem arises when a high pressure sodium lamp is used as the lamp 11 in the circuit of Figure 1. The resistance of high pressure sodium lamps increases over the life of the lamp. For example, if the lamp 11 in Figure 1 is a high pressure sodium lamp, and if the potentiometer 23 of Figure 1 is first adjusted so that the control circuit of Figure 1 furnishes 400 watts of power to the lamp 11, the voltage drop across the lamp when new would be approximately 95 volts. However, during the life of the lamp, this voltage can increase to 135 volts. This is because the lamp control circuit maintains a constant current through the lamp and choke parallel combination even though the- lamp resistance increases. For example, as the lamp resistance increases, the control circuit of* Figure 1 will increase the lamp voltage, plotted in Figure 3D, so that the current through resistor 15, plotted in Figure 3C, does not change. This voltage increase corresponds to an increase in the power consumed; and a significant increase in the cost of operating the lamp control circuit.Figure 28 illustrates another embodiment of the invention in which the foregoing problems are solved. The current regulation circuit ofFigure 28 comprises another transformer 960 connected in series with lamp 11 in a lamp control circuit similar to the lamp control circuit of gure 1. In the circuit of Figure 28, the power consumed is independent of the equivalent resistance of the lamp 11. Therefore, if the lamp 11 in Figure 285 is a high pressure sodium lamp, the power . consumed by the lamp control circuit will remain constant, even though the equivalent resistance of the lamp 11 may increase significantly.The transformer 960 has its primary winding10 961 connected in series with the lamp. Secondary winding 962 of the transformer 960 is wound to provide a reversed polarity with respect..to the primary winding 961, so that the current flowing from the voltage source 16 through the' lamp 1115 while the transistor 14 is on produces a negative voltage and reverse current in the secondary winding 962. Isolation diodes 963 and 964 are provided on the ungrounded side of the secondary winding 962.20 The negative voltage in the secondary winding causes a negative voltage to appear across the resistor 965 which is proportional only to the current through the lamp 11. Resistors 966 and967 are connected to form a summing node 968 for 25 the voltage across resistor 965. As discussed9 above in connection with Figures 1 and 3, the voltage across the resistor 15 is a function of the current through both the lamp 11 and the inductor 17. This voltage is applied to summing30 node 968 through summing node resistor 966. The negative voltage across resistor 965 is applied to. summing node 968 through summing node resistor 967. The resistance values of resistors 15,965,966,967 are preferably selected so that the contribution35 to the voltage across resistor 15 by current throug the lamp 11 is precisely nulled at the summing node968 by the negative voltage across the resistor 965. As a result, the voltage at the summing node 968 applied to the negative input 20a of the comparator 20 is a function exclusively of the current through inductor 17, and is independent of the current through the lamp 11. As a result, the comparator amplifier 20 will control the multivibrator 18 and transistor 14 independently of changes in the equivalent resistance of the lamp 11. Thus, the control circuit of Figure 28 does not increase the voltage applied to the lamp 11 as the lamp resistance increases. Therefore, the power consumed by the circuit of Figure 28 will not increase with lamp resistance as does the power consumed by the circuit of Figure 1.The lamp control circuit illustrated in the detailed schematic diagram of Figure 29 includes a combination of the features discussed above in connection with Figures 1, 27, and 28. Thus, the circuit of Figure 29. has a basic lamp control circuit including a gas discharge lamp 11, a switching transistor 14, a resistor 15, a multivibrator 18, and a comparator 20. However, the inductor 17 of Figure 1 is replaced instead by a transformer 970 having primary and secondary windings 971,972, respectively. The transformer 970 transforms the voltage from the voltage source 19 to the optimum operating voltage of the lamp 11. The basic lamp circuit including the lamp 11, the transistor 14, and the resistor 15, the multivibrator 18, the comparator 20, the potentiometer 23, and the transformer 970 operate in the manner described above in connection with the lamp control circuit of Figure 1. The high ignition voltage circuit of Figure 27 is included in the circuit of Figure 29 as the pulse transformer 950 having its primary winding 951 connected to discharge capacitors 953a,953b, and to controller 956. The diode 955 is connecte across the secondary winding 952 in the circuit5 of Figure 29 and prevents the inductance of the secondary winding 952 from affecting the operatio of the basic lamp control circuit, in the same manner as described above in connection with the pulse transformer circuit of Figure 27. The10 controller 956 is preferably a silicon controlled rectifier. The gate of the silicon controlled rectifier is connected to the multivibrator circuit 18. When the multivibrator circuit 18 turns the transistor 14 on, it simultaneously15 causes a voltage at the gate of the silicon contr rectifier 956 to turn the silicon control rectifi 956 on. This completes the circuit between the discharge capacitors 953a,953b, and the primary winding 951 of the pulse transformer 950. As20 described above in connection with Figure 27, thi generates a 2500-volt ignition voltage across the secondary winding 952, which drives the lamp 11. After ignition of the lamp, even though teh S.C. 956 continues to fire each time transistor 14 tur25 on, the 20-kHz switching frequency of transistor prevents significant voltage from building up in capacitors 953a,953b so that they no longer have any effect in the circuit.The current regulation circuit described abo30 in connection with Figure 28 is also present in t circuit of Figure 29, and includes the transforme 960 having its primary winding 961 connected in series with the lamp 11, and its secondary windin 962 wound with opposing polarity and connected35 through isolation diode 963 to resistor 965.Summing node 968 sums the voltage across resistor 15 through summing resistor 966 and the voltage across resistor 965 through summing resistor 967 and applies the resultant voltage to the input 20a of comparator 20. This current regulation circuit operates in the same manner described above in connection with the current regulation circuit of Figure 28.The circuit of Figure 29 also includes a delay circuit 980 connected to shut-down input 18a of the multivibrator circuit 18. The delay circuit 980 shuts down the multivibrator circuit 18 by applying a signal to shut-down input 18a as soon as power is first applied from the voltage source 19 in order to allow the discharge capacitors 953a,953b to have enough time to charge up to a sufficient voltage to ignite lamp 11. After a predetermined length of time, the delay circuit 980 no longer shuts down the multivibrator circuit 18, and the lamp control circuit of Figure- 29 begins to operate. The metal oxide varistor 27 is connected to the collector transistor 14 in the same manner as described above in connection with Figure 1. However, a second shut-down circuit 990 is provided which shuts down the multivibrator circuit 18 for a. predetermined length of time whenever the varistor 27 senses a high enough voltage across transistor 14 to break down. The low side of varistor 27 is connected to the input of the protective shut-down circuit 990.The output of the second shut-down circuit 990 is connected to the shut-down input 18a of multivibrator circuit 18. The second shut-down circuit 990 includes an astabile multivibrator 991. Breakdown of the varistor 27 causes the multivibrator 991 to change state and issue a signal to the shut-down input 18, which holds the multivibrator circuit 18 shut down for a predetermined length of time determined by the duration of the astabile state of the multivibrator 991. This arrangement permits repeated pulses to be produced for starting the lamp if ionization is not complete after the first pulse, by allowing the capacitors 953a and 953b sufficient time to recharge. Again, after the capacitors 953a,953b have recharged, the S.C.R. 56 again fires to cause a high voltage pulse across the lamp.10 | AMENDED CLAIMS(Received by the International Bureau on 22 May 1979 (22.05.1979)1. A circuit for energizing a gas discharge lamp comprising: first means (.17) for storing magnetic energy conne in parallel combination with the electrodes of the gas discharge lamp (11) ; second means (14) for connecting a power supply (1 to said parallel combination to provide a current flow in a first direction through said lamp; and third means- C18, 20) operatively coupled to said second means for interrupting the connection between sa power supply and said parallel combination for a predetermined length of time whenever the current through said parallel combination has increased to a predetermined level so that the current through said lamp is reversed to flow in a second, opposite directio for said predetermined length of time.2. The circuit of Claim 1 including means (23, 24) for varying said predetermined level of current for varying the intensity of the lamp.3. The circuit of Claim 1 comprising means (27) for protecting said second means against excessive voltages if said lamp is removed or fails and becomes an open circuit.4. The circuit of Claim 2 further including means (25) for varying said predetermined level as a function of ambient illumination.5. The circuit of Claim 1 wherein there is zero DC current through the electrodes of said gas discharge lamp.6. The circuit of Claim 1 comprising means (33) controlling more than one gas discharge lamp such that the required voltage supplied to the lamps by the circuit to ignite the lamps is not increased above the voltage required in the circuit to ignite one of said gas discharge lamps. 7. The circuit 'of Claim 1 wherein said second means comprises a means (.14) for switching said current and whereon current flows from said power supply (16) through said lamp (11) in one direction when saidOΛIPIA., —wiPo switching means (14)- is on and flows from said means (17) for storing magnetic energy through said lamp (11) in the opposite direction when said switching means (14) interrupts the connection between said power supply (16) and said parallel combination (11,17).8. The circuit of Claim 1 including an auto- transformer (59) having the dual functions- of said first- means and providing a step-up or step-down voltage to said lamp.9. The circuit of Claim 1 wherein said first means comprises a transformer (37,39) having a secondary winding (43) thereon for supplying power to said third means (18,20) . 10. The circuit of Claim 1 wherein said second means comprises a switching device (14) and a resistor (15) connected in series with said switching device (14) and wherein said third means comprises: a cne-shot multivibrator (18) having a first fixed time output state and a second variable time output state; means connecting the output of said multivibrator (18) to said switching device (14) to close said switching device during said first output state and to open said switching device during said second output state; and means responsive to a rise in voltage across said resistor (15) for triggering said multivibrator (18) to said second state. 11. The circuit of Claim 3 further comprising: means (110) for sensing the temperature of said protecting means (27) and operatively coupled to said third means (18,20) to maintain said second means (14) open when said protecting means (27) exceeds a predetermined temperature.12. A circuit for energizing a gas discharge lamp as defined in Claim 1, wherein said power supply comprises a rectified alternating current power supply (53) and wherein said predetermined length of time is shorter than the period of said AC power supply (53) , said circuit further comprising: fourth means (101,20) for programming said predetermined level to vary in accordance with the voltage of said rectified AC power supply (53) .13. The circuit of Claim 12 additionally comprising: fifth means (23) for varying said predetermine ratio.14. A circuit for energizing a gas discharge lamp as defined in Claim 12 further comprising a resistor (15) connected in series with said parallel combination (11,17), and wherein said second means (14) comprises a switching device (14) and wherein said third means comprises: a one-shot multivibrator (18) having a first fixed time output state and a second variable time ouptut state; means (80) connecting the output of said multivibrator to said switching device to close said switching device during said first output state and to open said switching device during said second output state; and means (20) responsive to a rise in voltage acr said resistor (15) and to the output of said rectif AC power supply (53) for triggering said multivibra (18) to said second state. 15. Apparatus as defined in Claim 14 wherein said triggering means comprises: means (20) for comparing said rise in voltage and said rectified AC power supply output and for triggering said one-shot multivibrator (18) to said first state when said rise in voltage reaches a predetermined fraction of said.JC power supply output. 16. Apparatus as defined in Claim 14, additionally comprising: means (111,113) prohibiting the rectified AC _. 5 voltage in said circuit from reaching a null.17. Apparatus as defined in Claim 16 wherein said prohibiting means comprises: a capacitor (111) connected to provide current to said lamp when the voltage of said capacitor 10 exceeds the voltage of said AC power supply output; and means (107) charging said capacitor from said AC power supply (53) .18.' A circuit for energizing a gas discharge lamp 15 as defined in Claim 1, wherein at least a portion (65-68) of said first means (59) is connected in parallel combination with the electrodes (200,201) of said gas discharge lamp (35) , the extent of said portion defining a voltage transforming ratio, said circuit further 20 comprising : fourth external conductor means (210) for increasing the voltage gradient inside said lamp during ignition of said gas discharge lamp independently of said voltage transforming ratio. 25 19. A circuit for energizing a gas discharge lamp as defined in Claim 18 wherein: said power supply has two terminals (215,231); said second means comprises a switching device (14) connected in series with a resistor (15) ; 30 said first means comprises an inductor (59) having two connection ends; said third means comprises: a one-shot multivibrator (18) having a first variable time output state and a second 35 fixed time output state; means (80) connecting the output of said multivibrator to said switching device to close said switching device during said first outpu state and to open said switching device during said second output state; and means (20) for putting said multivibrator in said second state when the voltage across said resistor (15) reaches a predetermined level; said circuit further comprising: means connecting said inductor (59) , sai switching device (14) and said resistor (15) in series across said two terminals (215,231), said switching device (14) connected between said resistor (15) and said inductor (59) , sai two terminals connected to said resistor and said inductor, respectively; means (65,68) connecting said pair of electrodes (200,201) in parallel combination with at least a portion of said inductor; and a starter aid conductor (210) located adjacen said lamp, extending parallel to the gap between said two electrodes, said conductor connected to one of said terminals (231) of said AC voltage supply. 20. An apparatus for energizing a gas discharge lamp, as defined in Claim 19, wherein : said portion (65-68) of said first means (59) which is connected in parallel combination with said pair of electrodes (200,201) includes the end of said inductor (59) which is connected to said switching device (14) .21. A circuit for driving a lamp as defined in Claim 1 wherein said second means comprises switching circuit means (14) having first and second switching states, said predetermined length of time corresponding to said first switching state, said circuit further comprising:- U EOMP «NA symmetry corrective means (355,370,375,380) connected to sense the difference between the time durations of said first and second states and also connected to vary the output of said power supply (300) in proportion to said difference.22. A circuit for driving a lamp as defined in Claim 21 wherein said power supply (300) comprises power oscillator means (615,620,625,630,635) for generating said output of said power supply (300) and for maintaining a constant and exclusively resistive input impedance at a frequency lower than the frequency of said oscillator means.23. A circuit for driving a lamp as defined in Claim 22 further comprising shut-down protective means comprising: means (27) for sensing voltage at said switching circuit means above a predetermined threshold voltage; means (470,495,505) responsive to said sensing means for applying a voltage to said power oscillator means to arrest said oscillator means.24. A-circuit for driving a lamp as defined in Claim 1, further comprising: regulating means (400,20) for changing said predetermined level in response to changes in the output of said power supply, said regulating means maintaining a substantially constant current flow through said lamp independently of fluctuations in the output of said power supply.25. A circuit as defined in Claim 25 further comprising: voltage limiting means (425) for limiting said predetermined level to a predetermined maximum value.26. A circuit as defined in Claim 1, further comprising:■ ^U E ?OMPI^ WIPO _& §»?NATiq§∑ means (950,953) for inducing a high voltage igniting pulse on said lamp, said means connected in series with said lamp. 27. A circuit for energizing a gas discharge lamp as defined in Claim 26, further comprising: means (955) preventing the impedance of said high voltage means from affecting operation of said second and third means (14,18,20) and lamp (11) upon ignition of said lamp.28. A circuit as defined in Claim 1, further comprising: means (960,965,968) for preventing increased lamp resistance from causing an increase in the power consumed from said supply.29. A circuit as defined in Claim 1, further comprising: means (960,965,968) for operating said second and third means (14,18,20) independently of current through said lamp.30. A circuit as defined in Claim 29 wherein said operating means senses current through said storing means (17) exclusively. | DATAPOWER; DATAPOWER INC | FELPER G; GERHARD F; HANDLER H; NELSON A |
WO-1979000454-A1 | 1,979,000,454 | WO | A1 | XX | 19,790,726 | 1,979 | 20,090,507 | new | A61K7 | A61K31 | A61K8, A61K31, A61P1, A61Q11 | A61K 8/58C, A61Q 11/00 | COMPOSITIONS AND METHODS FOR INHIBITING PLAQUE FORMATION | A dentifrice composition which inhibits plaque formation over an extended period of time. Said composition contains an effective amount of plaque-inhibiting quaternary organosiloxane of the formula (FORMULA) wherein R<s1>s is a alkoxy group having from 1 to 5 carbon atoms. R<s2>s is an alkylene group having from 1 to 25 carbon atoms and R<s3>s R<s4>s and R<s5>s are, individually, alkyl groups of from 1 to 25 carbon atoms, and X is an anion and iodine. | DESCRIPTION *Compositions and Methods for Inhibiting Plaque FormationTechnical FieldThis invention relates to compositions and methods useful in inhibiting the growth of cariogenic bacteria and the formation of plaque on teeth in an oral environment. The prevention of the formation of dental plaque is a highly desired result. Dental plaque results vhen cariogenic bacteria (e.g., Streptococcus utans) collect in colonies on the surface of teeth and form a tenacious deposit thereon. The presence of both the bacteria and the deposits is extremely detrimental to the health of the teeth because if the bacteria and plaque formation are not checked they may result in infected gingival tissue, the forma'tion of dental caries and periodontal disease. In extreme cases they may ultimately result in the loss of teeth.Background ArtMany attempts have been made to control cariogenic bacteria and plaque formation on teeth. For example, treatment with fluoride solutions or gels have been used to render the tooth enamel more resistant to the acid action caused by plaque.J These treatments are typically performed in a dental office at periodic, but not frequent, intervals. Such treatments do not, however, result in plaque control for an extended period.Even when the frequency of application of such treatments is increased only partial control has been shown. For example, studies wherein a fluoride-containing solution {1% fluoride concentration) was applied four to five times in the course of a year demonstrated only limited success due to the rapid re- establishment of plaque in the oral cavity. Additionally, the daily application of a fluoride gel by means of a custom-fitted vinyl mouthpiece for a period of twenty-one months showed no substantial change in plaque formation among treated and un-Λ treated patients. See Clinical Anicaries Effect of Repeated Topical Sodium Fluoride Application by Mouthpiece , Journal of the American Dental Association, V. 75, No. 3, September, 19β7, pp. 638-61.U.Other attempts at inhibiting the formation of plaque have also been made. For example, U.S. Pat. No. 3,733,399 describes toothpaste compositions which contain the enzyme invertase as the active ingredient. Another approach is disclosed in U.S. Pat. No. 3,89 ,li7 wherein the application to teeth of a • dialkyl pyrophosphate having from about 8 to k carbon atoms in the alkyl groups is described as useful in inhibiting plaque formation. However, these approaches require frequent (e.g., daily) use, in order to effectively control the cariogenic bacteria and inhibit the formation bf plaque over an extended period of time.Disclosure of InventionIn accordance with the present invention there is provided a dentifrice composition which contains a quaternary ammonium organosiloxane having the formula _ wherein R is an alkoxy group having from 1 to 5 carbon atoms, . R is an alkylene group having from 1 to 25 carbon atoms, andR 3, R k and R5 are, individually, alkyl groups of from 1 to 25 carbon atoms, and X is an anion, preferably selected from chlorine, bromine, fluorine and iodine. Preferably, composi- tions of the invention contain at least about 0.05 by weight,OΛiPIA * vvipo ' and most preferably from about 0.25$ to 1% by weight, of the quaternary ammonium organosiloxane.In another embodiment of the present fnvention there is provided a method for inhibiting plaque formation which com- prises contacting teeth with an effective amount of the above- described, composition.As it is used throughout this specification the term dentifrice refers to compositions for topical application to the teeth. Representative of such compositions are outh- washes or rinses, toothpastes, toothpowders, gels, etc.The present invention provides compositions and processes which are useful in controlling cariogenic bacteria and in¬ hibiting the formation of plaque over an extended period of - time despite relatively infrequent application of the compo- sitions to teeth.Best Mode for Carrying Out the InventionThe dentifrice compositions of the invention may be applied to the teeth by techniques such as painting or brushing, spraying, bathing and rinsing. Other means of application are also possible and will be. obvious to those in the art as a result of this disclosure. After application to the teeth it is preferred that a short period of time (e.g., one minute) pass before the user eats or drinks.The organosiloxanes useful in the present invention are known materials that may be prepared by simply agitating a warm mixture1 2 1 2 and an appropriate silane (e.g., [R ] -Si-R X where R , R andX are as described above). In the present invention it is preferred that R be a2 methoxy group (i.e., CH 0-); R be an alkylene group having1 to 10 carbon atoms (most preferably a prop^lene group, i.e.,-CH -CH -CH -); R be an alkyl group having from 10 to 20OMPI - It -carbon atoms (most preferably an octadecyl group, i.e., C. QH__) l 5 lo 37 •R and R each be methyl groups (i.e., CH -) and. X be chlorine.Thus, the most preferred siloxane may be represented by the formula:This compound may also be referred to as 3-(trimethoxysilyl)- propyl-dimethyloctadeeyl ammonium chloride. It may be obtained from Dow Corning Corporation as 9-5700 as a 0$ by weight solution of the siloxane in methanol. When provided in solution form, dentifrices of the present invention typically comprise a solution of the organosiloxane in water or a mixture of water and an alcohol. Typically the alcohol is a lower, non-toxic alkanol (e.g., ethanol, propanol, etc.). Liquid solutions of the siloxane are particularly use- ful in mouthwashes or rinses.A variety of other ingredients may be added to the denti¬ frices of the present invention. Thus, for example, prophy¬ lactic agents (e.g., supplemental caries-preventing aids) may be included. Moreover, polishing agents, soaps or detergents, flavoring and sweetening agents, thickening agents and humec- tants may also be included. Preferably these other ingredients are free from polyvalent metal such as calcium and magnesium. Representative of suitable prophylactic agents are sodium fluoride, stannous fluoride, potassium fluoride, hexylamine hydrofluoride, myristylamine hydro luoride, betaine fluoride, glycine potassium fluoride, etc. A particularly preferred pro¬ phylactic agent is sodium fluorine. Typically the fluoride prophylactic agents are present in sufficient concentration so as to provide an available fluoride ion concentration of up to about 2% by weight, and preferably in the range of about 0.5-2$ by weight, of the dentifrice composition.Representative of suitable polishing agents are abrasiveO- materials such as insoluble condensed phosphates such as calcium pyrophosphate, insoluble calcium polyphosphate (also known as . calcium polymetaphosphate) and highly polymerized sodium poly¬ phosphate (also known as sodium polymetaphosphate); and water- impervious cross-linked thermosetting resins such as the conden- sation products of melamine and urea with formaldehyde. Other suitable polishing agents will be obvious to those skilled in the art as a result of this disclosure.Preferably the polishing agent is not so abrasive so as to scratch or unduly abrade the tooth surface or the dentin.Rather it only cleans the tooth surface. The polishing agents may comprise up to 95$ by weight of the dentifrice composition. Representative of suitable soaps or detergents are the soaps of high molecular weight fatty acids such as sodium and potas- siu soaps of myristic, stearic palmitic acids and fatty acid mixtures of palm oil and coconut oil. Typical useful synthetic detergents include alkyl sulfates and sulfonates having alkyl groups of rom about 8 to 18 carbon/ atoms, such as sodium eauryl- sul ate, the sulfated fatty alcohols derived from coconut oil and palm oil, etc. These materials may comprise up to about 5% by weight of the dentifrice composition.Representative of suitable flavoring and sweetening agents are the oils of wintergreen, peppermint, spearmint, sassafras and anise. Additionally small amounts of sweetening agents such as saccharin, dextrose, levulose, etc. may also be em¬ ployed. These flavoring and sweetening agents may comprise up to about 5% by weight of the dentfifrice composition.Representative of suitable gelling or thickening agents are water-soluble salts of cellulose ethers such as sodium carboxy- methyl cellulose and sodium carboxy methyl hydroxy ethyl cellulose; natural gums such as gum karaya, gum arabic, and gum tragacanth; and colloidal magnesium-aluminum silicate or finely divided silica. Such thickening agents may comprise up to about 5% by weight of the dentifrice composition. Representative of suitable humectants are glycerine, sorbitol, other polyhydric alcohols. The.. umectants may com¬ prise up to about 35$ by weight of the dentifrice composition. Tests which demonstrate the effectiveness of the present 5 invention in inhibiting the growth of plaque were performed on Rhesus Monkeys. The teeth of the monkeys were clinically preconditioned to a plaque-free state by ultrasonic cleaning and subsequent dental prophylaxis using a soft rubber prophy¬ laxis cup and standard pumice-filled prophylaxis paste. The 0 teeth were then treated in various- fashions and the effect of the treatment upon the formation of plaque was observed.The effectiveness of plaque inhibition was measured by means of a plaque index number. Plaque index was determined by applying erythrosine B dye (FD&C Red dye #3, Color Index No. _ 5*i-30) to the teeth. This dye stains plaque but not tooth enamel. The stained plaque was visually observed and assigned a rating number using the following scale.0 No plaque0.25 Light plaque covering about l/ of tooth 0 surface0.5 Light plaque covering about 1/2 of tooth surface0.75 Light plaque covering about 3 of tooth surface 5 1.0 Light plaque covering entire tooth surface1.25 Heavy plaque on l/k of tooth surface, light plaque on remainder1.50 Heavy plaque on 1/2 of tooth surface, light plaque on remainder 0 1-75 Heavy plaque on 3 of tooth surface, light plaque on remainder2.0 Heavy plaque on entire tooth surfaceThe plaque was observed visually and rated periodically for the duration of the test. The ratings for each monkey were then 5 averaged to obtain the reported plaque index for each monkey.'BURE OMPI A solution containing 3-(trimethoxysilyl)-propyldimethyloc- tadecylammoniumchloride ( 9-5700 ) was ^applied to the upper incisors of the test monkeys. Solution A comprised 50$ Q9-5700 and 50$ methanol by weight. Solutions B & C each comprised 1$ 9-5700 , 1$ methanol and 98$ deionized water by weight. Different lots of 9-5700 were employed in Solutions B & C. The untreated teeth of the monkeys served as a control. They received no preventative treatment during the tests. The 'monkeys were fed twice a day with a diet which en¬ couraged plaque formation. The diet consisted of about 135(R) (R) grams of Purina^ New World Monkey Chow which had been softened with 200 milliliters of distilled water and to which118 grams of sugar had been added. The Monkey Chow (^R) is com- mercially available from Ralston Purina Co. and has a guaran¬ teed analysis ofCrude protein not less than 25-0$Crude fat not less than / 5-0$Crude fiber not more than 3-5$ Added minerals not more than 3.0$Ash not more than 6.0$ ■■ The ingredients in the Monkey Chow (Dwere ground yellow corn, soybean meal, ground wheat, corn gluten meal, dried skimmed milk, animal fat preserved with BHA, sucrose, brewers' dried yeast, salt, dehydrated alfalfa meal, vitamin B supplement, riboflavin supplement, calcium pantothenate, niacin, choline (source of vitamin D_), vitamin E supplement, iron oxide, iron sulfate, manganese sulfate, calcium iodate, calcium carbonate, dicalcium phosphate, anganous oxide, copper oxide, cobalt carbonate, zinc oxide.The results of the tests are as set forth in the following table: PLAQUE INDEX# OF DAYS TREATED CONTROLM0NKEY# SOLUTION TREATMENT TEST LENGTH TEETH TEETH1 A 1 1 .270 1.582 B 1 11. •35 1.253 C 1 12 •50 1.00 c 2 12 .187 1.312 h c 3 12 .281 1Λ315 ' c k 12 .56 1 36 c 1 12 1.625 1.75 c 5 9 .312 >2.07 c 2 9 •375 • 1.875TREATMENT1. On day 1 the solution was brushed onto the teeth with a paint brush and air dried for 2 minutes. There was no further treatment for duration of the test.2. The teeth were brushed daily ■wi.th the solution.3. On day 1 the solution was brushed onto the teeth with a paint brush, air dried for 2 minutes. Thereafter the treated teeth were brushed daily with deionized water. h . On day 1 the solution was brushed onto the teeth with a paint brush, air dried for 2 minutes. Thereafter the treated teeth were brushed daily with a composition of 1$ by weight in deionized water.5. The teeth were rinsed daily with lcc of the solution.Monkey 6 salivated excessively. Hence the single application of Solution C was rinsed away. However, when Solution C was later applied to the same monkey each day for 9 days it provided effective plaque control. Similar plaque control is achieved when the methanol employed in the solutions is removed or is replaced with a non-toxic alcohol such as ethanol. | - 9 -CLAIMS1. A dentifrice composition which contains a quaternary ammonium organosiloxane having the formula wherein R is an alkoxy group having from 1 to 5 carbon atoms-,-R,2~ is an alkylene group having from 1 to 25 carbon atoms and3 - 5 R , , RR aanndd RR5 aarree,, iinnddiivviidduuaallllyy,, aalllkyl groups of from 1 to 25 carbon atoms, .and X is an anion.2. A dentifrice composition in accordance with claim 1 wherein X is selected from chlorine, bromine, fluorine and iodine.3. A dentifrice composition according to claim 2 wherein said composition contains at least about 0.05$ by weight of said quaternary ammonium organosiloxane.A dentifrice composition according to claim 3 wherein R2 is methoxy, R is an alkylene group having from 1 to 103 carbon atoms, R is an alkyl group having from 10 to 20 5 carbon atoms, R and are, individually, methyl groups, and X is chlorine.A dentifrice composition according to claim k wherein R3 is a propylene group and R is an octadecyl group.6. The method of inhibiting plaque formation by contacting teeth with an effective amount of a dentifrice composition which contains a quaternary ammonium organosiloxane com¬ pound having the formula wherein R is an alkoxy group having from 1 to 5 carbon2 atoms, R is an alkylene group having from 1 to 25 carbon atoms, and R 3, R and R5 are, individually, alkyl groups•» of from 1 to 25 carbon atoms, and X is an anion.7. The method of claim 6 wherein X is selected from chlorine, bromine, fluorine and iodine.1 2 8. The method of claim wherein R is methoxy, R is an3 alkylene group having from 1 to 10 carbon atoms, R is k an alkyl group having from 10 to 20 carbon atoms, R and R are, individually, methyl groups, and X is chlo¬ rine.9- The method of claim 8 wherein R is a propylene group3 and R is an octadecyl group.10. The method of claim 6 wherein said teeth are contacted by a composition comprising at least about 0.05$ by weight of said quaternary ammonium organosiloxane compound. | MINNESOTA MINING & MFG; MINNESOTA MINING & MFG CO | ENGLE M; FLEUR L; LUCAS A; WEN R |
WO-1979000455-A1 | 1,979,000,455 | WO | A1 | XX | 19,790,726 | 1,979 | 20,090,507 | new | A61K7 | null | A61K8, A61Q11 | A61K 8/70, A61Q 11/00 | COMPOSITION AND METHOD FOR INHIBITING PLAQUE FORMATION | The object of the invention is to provide a dentrifice composition for inhibiting plaque formation on teeth. Said composition contains a compound having the formula (R<uf>u)<um>u YX wherein R<uf>u is a fluoroaliphatic radical having from about 4 to 16 carbon atoms, Y is a calcium-complexing moiety, X is a terminal group which does not interfere with the complexing ability of said calcium-complexing moiety, and m is an integer of at least one. | DescriptionComposition and Method for Inhibiting Plaque FormationTechnical Field This invention relates to compositions and methods useful in inhibiting the growth of cariogenic bacteria and the formation of- plaque on teeth in an oral envi¬ ronment.Background Art The prevention of the formation of dental plaque is a highly desired result. Dental plaque results when cariogenic bacteria (e.g., Streptococcus Mutans) col¬ lect in colonies on the teeth and form a tenacious de¬ posit thereon. The presence of the bacteria and the deposits is extremely detrimental to the health of the teeth because if left unchecked they may cause infec¬ ted gingival tissue, the formation of dental caries and peridontal disease. In extrene cases they may ul¬ timately result in the loss of the teeth. Many attempts have been made to control the forma¬ tion of plaque. Thus, fluoride solutions and gels have been used. Such are typically performed in a dental office at periodic, but not frequent, intervals so as to render the tooth enamel more resistant to the acid action caused by plaque. Such treatments do not, however, result in plaque control for an extended per¬ iod of time.Even when the frequency of application of such so¬ lutions and gels is increased only partial control has been shown. For example, studies wherein a fluoride- containing solution (1% fluoride concentration) was ap¬ plied four to five times in the course of a year demon¬ strated only limited success. Moreover, the daily ap¬ plication of a fluoride gel by means of a custom-fitted polyvinyl mouthpiece for a period of 21 months also showed no substantial change in plaque formation among treated and untreated patients. See Clinical Anti- caries Effect of a Repeated Sodium Fluoride Application by Mouthpiece , Journal of the American Dental Associa- tion, V.. 75, No. 3, September, 1967, pp. 638-644.Other attempts at inhibiting the formation of plaque have also been made. Thus British patent 1,319,247 de¬ scribes dental compositions which comprise a dental ve¬ hicle and a zinc, copper or zirconium complex of a fluorinated beta-diketone. These compounds are said to reduce the solubility of tooth enamel in the acids pro¬ duced by bacteria in the mouth.Disclosure of InventionThe present invention provides a dentifrice composi- tion, substantially free from materials containing++ ++ polyvalent metal elements (e.g. Ca , Mg , etc.) which contains a fluorochemical material having the formula (R£ t)mYX. In this formulaRf is a fluoroaliphatic radical having from about 4 to 16 carbon atoms;Y is a calcium-complexing moiety which has a forma¬ tion constant in the range of about 0.5 to 8, wherein said calcium complexing moiety forms a complex struc¬ ture with calcium, which structure contains up to about 20 atoms in its backbone;X is a terminal group which does not interfere with the ability of said complexing moiety to form';• said complex structure with calcium; and m is an integer of at least one.Preferably compositions of the present invention comprise at least about 0.05%- by weight, and most pre- ferably from about 0.1% to 1% by weight, of the fluoro- chemical compound.In another embodiment of the present invention there is provided a method for inhibiting plaque for¬ mation which comprises contacting teeth with an ef- fective amount of the above-described dentifrice compo¬ sition.As it is used throughout the specification, the term dentifrice refers to compositions for topical application to teeth. • Representative of such composi- tions are liquids (e.g. mouthwashes and rinses, etc.) and toothpastes (in the form of gels, powders or pastes) etc.Best Mode for Carrying Out the Invention The dentifrice compositions of the invention may be applied to teeth by a variety of techniques including, for example, painting or brushing, spraying, bathing and rinsing. Other means of application are also pos¬ sible and will be obvious to those skilled in the art as a result of this disclosure. Fluorochemical materials, useful in the invention have the formula set forth above. In this formula Rf is a fluorinated, saturated, usually monovalent, ali¬ phatic radical. The , radicals are stable, inert, nonpolar moieties which can be both olephobic and hy- drophobic. They can be straight chain or branched chain radicals. Additionally, if the radicals are sufficiently large, they may be cyclic or combinations_0MPI__ of cyclic, branched and straight chain (e.g. alkyl- cycloaliphatic radicals) . The skeletal chain of the Rf radical can include catenary oxygen and/or trivalent nitrogen hetero atoms bonded only to carbon atoms. Such hetero atoms provide stable linkages between fluorocarbon groups and do not interfere with the in¬ ert character of the radical.R_ has from about 4 to 16 (preferably from about 6 to 12) carbon atoms. Additionally the Rf radical is preferably fully or substantially fully fluorinated. Thus the preferred Rf radicals are perfluoroalkyl groups (e.g. C F_ .-i-)- Moreover, the terminal portion of the _e group preferably contains a -CF, group, and most preferably the terminal .portion also has at least three fully fluorinated carbon atoms (e.g. CF3CF2CF2-) .Generally the Rf radical contains about 40-80 per¬ cent by weight (preferably 50-80 percent by weight) fluorine. As a result, the corresponding fluorochemi- cals contain from about 4 to 70 percent by weight fluorine.Complexing moieties (Y) useful in the present in¬ vention may be mono- or polyderitate. The fluorochemi- cals form complex (e.g. chelate) structures with cal- cium through the Y group. These complex structures may contain up to about 10 atoms in their backbone. Preferably they contain from about 5 to 6 members therein. Additionally, the calcium complexing moi¬ eties have a formation constant within a defined range. This constant is expressed in terms of log,0K. Useful calcium complexing moieties have a formation constant in the range of about 0.5 to 8. Values of more than 8 indicate very strong calcium chelators. Such chelators are undesirable because they decalcify the tooth (i.e. withdraw the calcium from the tooth) thereby weakening its resistance to disease and wear. The formation constant is based upon a complex formed between the fluoroche ical and an organic li- gand. The value is determined at about 25°C. and an ionic strength approaching 0 from the following: M + L t~== ML In these formulae [M] represents the concentration of the complexing agent; [L] represents the concentration of the organic ligand; and [ML] represents the concen¬ tration of the complex at equilibrium.The chelate structure formed between the fluoro- chemical and calcium of the tooth may be represented by the general structure:r wherein Rf, Y, X and m are as described above. For purposes of discussion the Y group is hereinafter some¬ times represented by the formula -A-Z-A-. Thus struc¬ ture I_ may also be represented by- --C *-,a++ ' ~ - wherein each Rf, R and m are as described above; each A is an electron donating moiety that may be the same or different and is selected from (i) hetero atoms se¬ lected from oxygen, nitrogen and sulfur, provided that when- A is nitrogen it is either a primary or sec¬ ondary nitrogen; and (ii) groups which contain said oxygen, nitrogen and sulfur hetero atoms; and Z is a connecting group which does not interfere with the for- mation of the chelate structure.Representative examples of useful A groups are ke- tone groups, hydroxyl groups, carboxyl groups, amino groups, sulfhydryl groups, thionogroups, thiologroups, mercapto groups, etc. Fluorochemicals which contain more than one of these A groups are also useful (e.g. hydroxy-carboxylic, sulfhydryl-carboxylic, sulfhydryl- thiolo, sulfhydryl thiono, amino-mercapto, etc.).Representative examples of useful Z groups include alkylene radicals containing from about 1 to 20 carbon atoms; and arylene radicals of from about 5 to 20 car¬ bons. Hetero atoms (e.g nitrogen, oxygen and sulfur) may appear in the Z groups. However they must not in¬ terfere with chelation of the calcium.Still other Y groups useful in the present inven- tion comprise quaternary nitrogen groups. These groups may be represented by the formulaR6 ΘN - R5wherein R 4 and R5 are methyl and R6 is -fCHpthW wherein b is an integer of from about 1 to 6 and is selected from the group consisting of hydrogen, hydroxyl andTypically the quaternary nitrogen moieties are as¬ sociated with an anionic moiety. ex¬ amples of such anionic moieties -NO- (r). Still other anionic moieties are also usefulO - as will be understood by those skilled in the art.X groups useful in the fluorochemical materials do not interfere with the ability of the Y group to form complex structures with calcium. Representative ex- amples of suitable X groups are hetero atoms such as hydrogen and alkali metals (e.g. potassium and sodium) , alkyl radicals, especially those containing from about 1-4 carbons, carboxyl and sulfonate radicals, aryl radicals (e.g. those- containing from about 5 to 6 car¬ bon atoms), ammonium radicals and heteroatoms.In an alternative embodiment of the present inven¬ tion the fluorochemical material may be represented by the formula (Rf) QYZ wherein Rf, Y, X and m are each as described above and wherein Q is a polyvalent (i.e. at least divalent) linking group through which R^ and Y are bonded together. Representative examples of use¬ ful Q groups include polyvalent aliphatic; polyvalent aromatic, oxy, thio, carbonyl, sulfone, sulfoxy, imino, and combinations thereof such as oxyalkylene, iminoal- kylene, iminoarylene, sulfonamideo, carbonamido, sul- fonamidoalkylene, carbonamidoalkylene, urethane, etc. Representative examples of polyvalent aliphatic Q groups include -CH2-CH2~ and -CH2C (CP20)2~. Repre¬ sentative examples of polyvalent aromatic Q groups in- eludeRepresentative examples of imino Q groups include -NH- and -N(C„H5)-. Representative of suitable urethane Q groups include -CH2CH2OCONH- and, _O PI_ Specific examples of fluorochemical materials which conform to the formulae described previously are set forth in Table 1. The specific formula and the portion of each material attributable to each element of the generic formula are given. TABLE 1SPECIFIC FORMULACQF1[C8F[C8FTABLE 1 (continued)SPECIFIC FORMULA R* QC8F17S02 (CH2)10COOH •SO. ■tl(CH2)10•C S-0C8F17CQF17SO2N(C2H5)CH2CO2H(COCH2CH2)3N 02- -H(H0CH2CH2)3NC8F17 SO, -N(C2H5)CH2COther ingredients may also be added to the compo¬ sitions of the present invention. Thus, for example, prophylactic agents, polishing agents, surfactants, flavoring and sweetening agents, thickening agents and humectants may be included using techniques which are known to the art.Such other ingredients must be substantially free of polyvalent metal (e.g. calcium, magnesium, etc.). The presence of such metals in these ingredients pre- vents the compositions of the invention from exhibit¬ ing the desired control over cariogenic bacteria and plaque formation. While the reason for this is not fully understood, it is believed that these metals interact with the fluorochemical materials before ap- plication of the composition to teeth thereby prevent¬ ing them from interacting with the calcium of the teeth. Thus while these ingredients may contain a minor amount of polyvalent metal, the total amount of such ions present must not prevent the fluorochemical materials from interacting with the teeth. Preferably these other ingredients are completely free from any polyvalent metal.Representative prophylactic agents include supple¬ mental caries-preventing materials such as sodium flu- oride, stannous fluoride, potassium fluoride, hexyl- amine hydrofluoride, myristylamine hydrofluoride, be- taine fluoride, glycine potassium fluoride, etc. A particularly preferred fluoride is sodium fluoride. Typically the prophylactic agents are present in suf- ficient concentration so as to provide an available fluoride ion concentration of up to about 2% by weight, and preferably in the range- of about 0.5-2% by weight, of the dentifrice composition. Suitable polishing agents include, for example, water-impervious cross! inked thermosetting resins such as the condensation products of melamine and urea with formaldehyde. Other suitable polishing agents will be obvious to those skilled in the art as a result of this disclosure. Preferably the polishing agent is not so abrasive so as to scratch or unduly abrade the surface or the dentin. Rather it only cleans the tooth surface. The polishing agents may comprise up to 95% by weight of the dentifrice composition.Surfactants may also be employed in compositions of the invention. Suitable surfactants include, for example, detergent materials and are preferably non- ionic. Representative examples of useful surfactants include lauric onoethanol ami de , 1 aur c-myristic mono- ethanolamide, ricinoleic al kanol mides , fatty acid al kanolamides (e.g., coconut diethanolamide) , lauryl . dimethyl amine oxide, glycerol monolaurate, glycerol monostearate, pentaerythri tol monooleate, sorbitan monooleate, ethoxylated castor oil, nonyl phenol ethoxolate, etc. The surfactants typically comprise up to about 5% by weight of the dentifrice composition. Suitable flavoring and sweetening agents which may be employed in compositions of the invention include, for example, the oils of wintergreen, peppermint, spearmint, sassafras and anise. Additionally small amounts of sweetening agents such as saccharin, dex¬ trose, levulose, etc. may also be added to such compositions. These flavoring and sweetening agents may comprise up to about 5% by weight of the denti¬ frice composition.Suitable gelling or thickening agents which may be employed in compositions of the present invention in¬ clude, for example, natural gums such as gum karaya, gum arabic and gum tragacanth; and finely divided silica. Such thickening agents may comprise up to about 5% by weight of the dentifrice composition.Suitable humectants which may be employed in compo¬ sitions of the invention include glycerine, sorbitol, and other polyhydric alcohols. The humectants may com¬ prise up to about 35% by weight of the dentifrice com¬ position.The effectiveness of the present invention in inhib- iting the growth of plaque was demonstrated by both in vitro and in vivo tests. These tests are described more fully in the following examples.Example 1 In vitro tests were performed on plaque-free bovine teeth. The teeth were dipped into a composition of the invention for 30 minutes and then air dried for 30 min¬ utes. Untreated teeth were used as controls. The treated and untreated teeth were then suspended in tubes of a test media comprising 18 milliliters of ac- tinomyces broth, 2 milliliters of a 20% aqueous su¬ crose solution and 0.2 milliliters of a 24 hour viable culture of Streptococcus utans. The teeth and test tubes were incubated at 37°C. for 24 hours, after which the teeth were transferred to new test tubes of fresh test media and again incubated at 37°C. for 24 hours. The procedure was repeated for three days or until attachment of plaque to the control teeth was noted.The compositions used to treat the teeth comprised 1% by weight fluorochemical and 99%. by weight deionized water. Compositions containing the following fluoro- chemicals, each of which had a formation constant in the range of about 0.5 to 8, were found to prevent the formation of plaque in this test: C8F17SO2- -CH2COOHEt[C8F1 )2]N0Θ3Example 2In vivo tests were performed on Rhesus Monkeys. Each monkey received a complete dental prophylaxis wherein their teeth were ul trasonically cleaned and then polished using a soft rubber prophylaxis cup and standard pumice-filled prophylaxis paste. The test compounds were applied to the upper central and medial incisors of each monkey by brushing about 0.5 cc. of a solution of the fl uorochemical material in deionized water and allowing the teeth to air dry for about 30 seconds. Various concentrations of the fluoroche - icals were employed in the solutions tested. The lower central and medial incisors of the monkeys served as control teeth. Except for the initial dental prophylaxis, the control teeth received no treatment during the tests-. The teeth were observed for up to 14 days to determine the effect of the treatment upon the formation of plaque.The monkeys were fed twice a day with a diet which encouraged plaque formation. Each feeding consisted of about 135 grams of Purina R New World Monkey Chow R which had been softened with 200 grams distilled water and to which had been added 118 grams of sugar. The- R3 Monkey Chow is commercially available from RalstonPurina Co. It has a guaranteed analysis of:Crude protein not less than 25.0%Crude' fat not less than 5.0%Crude fiber not more than 3.5% 0 Added minerals not more than 3.0%Ash not more than 6.0%The ingredients in the Monkey Chow were ground yellow corn, soybean meal, ground wheat, corn gluten meal, dried skimmed milk, animal fat preserved with BHA, su- 5 crose, brewers' dried yeast, salt, dehydrated alfalfa meal, vitamin B,„ supplement, riboflavin supplement, calcium pantothenate, niacin, choline chloride, men- adione sodium bisulfite (source of vitamin K activity) , folic acid, pyridoxine hydrochloride, thia in, ascor- 0 bic acid, vitamin A supplement, D activated animal sterol (source of vitamin D~), vitamin E supplement, iron oxide, iron sulfate, manganese sulfate, calcium iodate, calcium carbonate, dicalcium phosphate, man- ganous oxide, copper oxide, cobalt carbonate and zinc 5 oxide.The effectiveness of plaque inhibition in this test was measured by means of a plaque index number. The plaque index was determined by applying Erythrosine B dye (further identified as FD&C Red dye #3, Color In- Q dex No. 45430) to the teeth. This dye stains plaque but not tooth enamel. The stained plaque was visually observed and assigned a number using the following scale. PLAQUE SCALE0 No plaque0 , . 25 Light plaque covering about 1/4 of tooth surface0. , 5 Light plaque covering about 1/2 of tooth surface0. , 75 Light plaque covering about 3/4 of tooth surface1 . , 0 Light plaque covering entire tooth surface1 . . 25 Heavy plaque on 1/4 of tooth surface, light plaque on remainder1.50 Heavy plaque on 1/2 of tooth surface, light plaque on remainder1.75 Heavy plaque on 3/4 of tooth surface, light plaque on remai nder2.0 Heavy plaque on entire tooth surfaceThe teeth were stained and observed visually periodi¬ cally throughout the test. The ratings were average to form the reported plaque index. The results of these tests are set forth in Table The fluoro- chemical materials employed were[C8F1 )2]N0 Θ3[CgFn 2]H,P0 Θ CgF17S02(C2H5)CH2C02H (H0CH2CH2)2N TABLE 2FLUORO¬ PLAQUECONCEN¬ TEST INDEX CHEMICAL APPLICATION TRATION LENGTH, TREATED CONTROLMONKEY MATERIAL METHOD ( t. %) (Days) TEETH TEETH1 A * 2 14 0.25 1.6872 A * 1 14 0.125 1.3753 A * 0. 5 14 0.125 3.4374 A * 0. 25 14 0.50 1.3755 A * 0. 125 14 0.666 2.5010 1 A ** 1 13 0.35 1.151 A ** 1 8 0.333 1.756 , A ** 1 10 0.375 1.317 A ** 1 10 0.187 1.568 A ** 1 12 0.4 1.359 A ** 1 8 0.166 2.01 B * 1 14 0.70 1.606 B * 1 8 0.5 2.07 B * 1 8 0.208 1.5010 B * 1 10 0.125 1.31252 C * 1 10 0 1.1252 C * 1 14 0.1 1.35TABLE 2 (continued)FLUORO¬ CONCEN¬ TEST PLAQUE INDEXCHEMICAL APPLICATION TRATION LENGTH TREATED CONTROLMONKEY I MATERIAL METHOD ( t. &) (Days) TEETH TEETH10 C * 1 14 0.416 1.584 D * 1 14 1.083 1.87511 D * 1 13 0.11 1.3912 E * 1 10 0 1.00Application Techniques* Daily brushing with fluorochemical solution ** Daily rinsing with fluorochemical solution * -*I | Claims1. A dentifrice composition, substantially -free from polyvalent metal, which composition contains a fluorochemical compound having the formula (Rf) YX whereinR is a fluoroaliphatic radical having from about 4 to 16 carbon atoms;Y is a calcium-complexing moiety which has a formation constant in the range of about 0.5 to 8, wherein said calcium complexing moiety forms a complex structure with calcium, which structure contains up to about 20 atoms in its backbone;X is a terminal group which does not inter¬ fere with the ability of said calcium complexing moiety to form said complex structure with calcium; and m is an integer of at least one.2. A composition in accordance with claim 1 wherein said fluorochemical comprises at least about 0.05% by weight of said composition.3. A composition in accordance with claim 2 wherein Rf comprises perfluoroalkyl groups.4. A composition in accordance with claim 3 wherein laid fiuόr&ehemical forms a chelate structure with 5. A composition in accordance with claim 1 wherein Y comprises a quaternary nitrogen group. 6. A composition in accordance with claim 1 wherein X is selected from the group consisting of alkyl radicals containing from about 1 to 4 carbon atoms, carboxyl radicals, sulfonate radicals, aryl radi- cals containing from about 5 to 6 carbon atoms and heteroatoms selected from the group consisting of hydrogen and alkali metals.7. A composition in accordance with claim 1 wherein said fluorochemical has the formula CoFl,_/S0 ΔNjCH 2.COOMC2H5 wherein M is selected from the group consisting of hydrogen, alkali metal and ammonium radicals.8. A composition according to claim 1 wherein said fluorochemical has the formula9. A composition according to claim 1 wherein said fluorochemical has the formula C7FlcCCH C-0 O10. A composition according to claim 1 wherein said fluorochemical compound has the formula (Rf) QYX wherein Q is a polyvalent linking group through which R- and Y are bonded together and which does not interfere with the calcium-complexing ability of Y. 11. The method of inhibiting plaque formation compris¬ ing contacting teeth, in an oral environment, with an effective amount of a dentifrice composition, substantially free from polyvalent metal ions, which composition contains a fluorochemical com¬ pound having the formula (Rf) YX whereinRf is a fluoroaliphatic radical having from about 4 to 16 carbon atoms;Y is a calcium-complexing moiety which has a formation constant in the range of about 0.5 to 8, wherein said calcium-complexing moiety forms a complex structure with calcium, which structure contains up to about 20 atoms in its backbone;X is a terminal group which does not.inter- fere with the ability of said calcium complexing moiety to form a complex with calcium; and m is an integer of at least 1. | MINNESOTA MINING & MFG; MINNESOTA MINING & MFG CO | CHANG R; ENGLE M; FLEUR L |
WO-1979000458-A1 | 1,979,000,458 | WO | A1 | EN | 19,790,726 | 1,979 | 20,090,507 | new | A01K29 | null | A01K1 | A01K 1/01B1 | DOG'S SANITARY BOX | An animal toilet including a cabinet (1) adapted to be made from different materials including a sloping flour (2) and a drain (3) for removing waste. The floor (2) is covered by removable iron bars (4). The cabinet (1) has side walks (9) provided with depressions (19) that serve as shelves. Suitable piping (12), (13) is mounted on the cabinet (1) providing hot water and cold water, respectively. A small post (21) is positioned in the cabinet for attracting an animal into the same. | -DOG'S SANITARYBOXTITLE OF INVENTIONDescriptive report of invention of patent of DOG'S SANITARY BOX . The present invention concerns a dog's pre-manufactured box of fiber glass, plastic, stainless steel, enamel melted iron, plastic recovered, - of brick with internal and external walls built with internal and external -walls built with tiles or ceramic or even yet with some other adequated materials, trying to solve definitively the prlblem envolving the excrements of dog's which are daily deposited on the street walking side, squares and other public places, mainly on the beaches, gardens - and even in the apartments service areas, garages and residences, which change the salutar habits of walking or strolling in a constant worry of observing and looking the street's ground . This fact doesn't only disturbs us as it also constitutes a case of public health, once that the dog's excrements are transmissors agents of verminousis and other - equally contact and undesirable diseases, the above mentioned dog's sanitary boxes, can be correctly installed inside the apartments, building common areas, garages, residences, life save areas, gardens, squares, considerably reduced the excrements quantity with its negative load of contagious diseases and with all sorts of inconveniences - resulting of this ambiental polution. Dogs are, save few exceptions, cleavers and they do rapidly assimilate new systems and habits in order to satisfy their phisiological needs. By the drawings, in Figure 1, dog's sanitary boxes can be seen as a drawing and in Figure 2, a cut in a longitudinal vertical position. - As one can deduce by looking at the two Figures, the sanitary box is made out of a cabinet (1) of brick material which has its internal and exterior parts covered with vitrified tiles, or, manufactured or in a pre-manufactured fiber glass welding, plastic or steel plate, or byOMPI/»_,__ WIPO any other suitable material, a self siphoned circulated basin (2 _ 3) which has as floor melted iron or other kind of material which is recovered by one or more bars (4) even of iron, which can be removed, articulated in a hinge joint leaded (5) and hplden on supports (6) and - (7) presenting an opening properly connected with the sewerage (3) of the basin (2) in order to rely on them, dogs in the act of making their phisiological needs, the excrements will reach the sewerage without touching them. On the walls (9) of adequated thickness is located the connection of pipping (10) with water net of the area in - which the box will be built, and the ramifications (11) referring to the exits for adaptations of small showers of hot water (12) , and cold water (13) connected to plastic hose (14) of proper lenght, and also a general water register and a discharge box (16) and its starting botton (16a) with pipping (17) of discharge valve hydraulic-basin (2) - the set is integrated by a register (18) for a siphon (3) with view in case of obstruction by things occasionally dropped in. The cabinet walls will have depressions (19) with shalves, making small and useful closets in order to keep bath articles, medicines and other equipage (5). The set is completed by a system of sanfonated curtains - (20) and also an independent element, representing a small post or a water tap miniature or even a trunk tree (21) which will function as a motivation for the male animals for urinating, since female dogs do not need such an estimulation. These pre-manufactured cabinets are built on the planned areas, in the building projects, on which foreseen - pipping of water and sewerage feeding can be installed, or in buildings already built or under construction, will be build or installed in the service areas near to sinks for clothes' washing or maid's W.C., in order to use the already existing pipping. In houses, garages, basements, public and private gardens, in service areas of apartments - buildings under construction, or already built, it can be installed two or more boxes in order to serve as public or collective sanitary .C. for the dogs which live in the building. | C A I M S1 - DOG'S SANITARY BOX is characterized by having pre-manufactured cabinets or having them built on the chosen area, having as floor a self-siphoned basin with sewerage, which is recovered - by removable iron bars, provided with an opening coinciding with the basin connected with the sewerage and having walls provided with depressions with shalves, composing closets to keep hygienic articles or dogs' medicines, also integrated with pipping connection for water and sewerage distribution net. - 2 - DOG'S SANITARY BOX , comprehending all details included on the claim 1, and being characterized by presenting a finishing, sanfonated curtains and also internally having: water discharge box connected with a floor basin, and registers for adaptations for corresponding hoses which correspond to small showers - of hot and cold water, being the whole' set integrated by an element reproducing the characteristics of a post miniature, water tap made out of metal or plastic, or even a trunk tree for motivating male animals.OMPI | MARTI R | MARTI R |
WO-1979000475-A1 | 1,979,000,475 | WO | A1 | EN | 19,790,726 | 1,979 | 20,090,507 | new | C07G7 | G01N31 | C12N9, C12Q1, G01N33 | C12N 9/16, G01N 33/573 | PROSTATIC CANCER DETECTION | An immunochemical method for detecting prostatic acid phosphatases has been developed which is useful in clinical laboratory testing for prostate cancer and in enzyme and protein determinations. An isoenzymatically homogeneous prostatic acid phosphatase antigen is prepared by isolating purified acid phosphatase from cancerous human prostate tissue. The antigen stimulates the production of diagnostic antibodies which are highly specific, do not cross-react with other acid phosphatase isoenzymes and can be used in countercurrent immuno-electrophoresis (showing a sensitivity of 0.4 I.U. of enzyme activity or 20 ng/ml enzyme protein) and in a solid phase fluorescent immunoassay (showing a sensitivity of 60 pg/ml enzyme protein with excitation of the alpha-naphthol hydrolysis product at 340 nm and emission at 465 nm) with no false positives and few false negatives in diagnosing cancer of the prostate. | PROSTATIC CANCER DETECTIONDESCRIPTION OF THE INVENTION This application is a continuation-in-part of copending, commonly assigned U.S. Patent Application Serial No. 866,918 filed January 4, 1978. This invention was supported in part by Grants No. CA-15126, CA-15437 and CB-43977 from the National Cancer Institute, U.S. Public Health Service.Technical Field This invention relates to a diagnostic reagent and method for the immunochemical detection of serum prostatic acid phosphatase. More particularly, this invention relates to a purified isoenzyme antigen and antibodies specific thereto which are suitable for use in prostatic cancer detection by laboratory methods.Background Art Acid phosphatases are enzymes capable of hydrolyzing phosphate monoesters in an acid medium at around pH 5. Human acid phosphatases are normally found in virtually all human tissues, e.g., the prostate, bladde'r, kidney, liver, spleen, platelets, erythrocytes brain, bone marrow, lung, intestine and testicles. Originally believed to be a single enzyme, human acid phosphatases all share the common enzymatic property of hydrolyzing phosphate esters in an acid medium but are now known to exist in a plurality of at least fifty biochemically distinct forms. For example, erythrocyte acid phosphatase is a protein having a molecular weight of about 20,000 daltons while prostate acid phosphatase is a glycoprotein having a molecular weight of about 100,000 daltons and which, in samples extracted from cancerous prostate tissue, exists in at least eight electrophoretically separable isoenzy e forms as recently reported by Chu et al. in Cancer Treatment Reports 6_1: 193 (1977) , the contents of which are incorporated by reference herein.The elevation of serum acid phosphatase activity in patients having metastasized prostate carcinoma was first reported by Gutman et al. in J. Clin. Invest. _l_ι 473 (1938). In cancer of the prostate, prostatic acid phosphatase is released from the cancer tissue into the blood stream with' the result that the total serum acid phosphatase level greatly increases above normal values. Numerous studies of - this enzyme and its relation to prostatic cancer have been made since that time, e.g., see the review by Yam in A er. J. Med. 5j5: 604 (1974). However, the measurement of serum acid phosphatase by conventional spectrophotometric methods often fails to detect prostatic cancer in its early stages. In general, the activity of serum acid phosphatase is elevated in about 65-90% of patients having carcinoma of the prostate with bone metastasis; in about 30% of patients without roentgenological evidence of bone metastasis; and in about only 5-10% of patients lacking clinically demonstrable metastasis.Shinowara et al. reported a method for determining serum acid phosphatase in J. Biol. Chem. 142: 921 (1942) which employs glycerophosphate as the enzyme substrate and spectrophotometrically measures the product of enzyme reaction, phosphate ion, as a colored phosphomolybdate complex. Since serum normally contains an appreciable quantity of phosphate ions and that released by the acid phosphatase is small in relation thereto, it is necessary to carry out a blank determination of normal serum phosphate content for each sample being tested and to carefully determine the difference in total phosphate content between the blank control and the actual test containing additional enzyme-released phosphate.Babson, U.S. Patent 3,002,893, the contents of which are incorporated by reference herein, describes a method for determining serum acid phosphatase which employs the buffered salt of an alpha-naphthyl phosphate as the enzyme substrate. While initially believed specific for the detection of acid phosphatase released by the prostate gland, subsequent investigators have reported difficulties in realizing this objective. For example, fairly cumbersome inhibition techniques, e.g., with tartrate or formalin, must generally be' employed to satisfactorily mask interfering activity of erythrocyte acid phosphatase. Furthermore, this substrate has about the same activity for platelet acid phosphatase as for prostatic acid phosphatase, which cannot be eliminated by the use of such inhibition techniques.Roy et al., U.S. Patent 3,823,071, the contents of which are incorporated by reference herein, describes the use of water-soluble metal salts of thymolphthalein monophosphate as substrates which exhibit improved specificity in comparison with beta-glycerolphosphate and alpha-naphthylphosphate in the detection of prostatic acid phosphatase. However, Ewen et al. have reported in Clin. Chem. ^22: 627 (1976) that thymolphthalein monophosphate is a non-specific substrate for prostatic acid phosphatase, cross-reacting with a large number of other acid phosphatases.The aforementioned attempts to develop a specific test for prostatic acid phosphatase have met with only limited success because techniques which rely on enzyme activity on a so-called specific substrate cannot take into account other biochemical and immunochemical differences among the many acid phosphatases which are unrelated to enzyme activity of prostate origin. In the case of isoenzymes, i.e. genetically defined enzymes having the same characteristic enzyme activity and a similar molecular structure but differing in amino acid sequences and/or content and therefore immunochemically distinguishable, it would appear inherently impossible to distinguish different isoenzy e forms merely by the choice of a particular substrate. It is therefore not surprising that none of these prior art methods is highly specific for the direct determination of prostatic acid phosphatase activity; e.g. see Cancer 5_: 236 (1952); J. Lab. Clin. Med. 2: 486 (1973); Clin. Chem. Acta. 44: 21 (1973); and J. Physiol. Chem. 56. 1775 (1975).In addition to the aforementioned problems of non-specificity which appear to be inherent in many of the prior art reagents employed for the detection of prostate acid phosphatase, there have been reports of elevated serum acid phosphatase associated with other diseases, which further complicates the problem of obtaining an accurate clinical diagnosis of prostatic cancer. For example, Tuchman et al. in Am. J. Med. 2__ι 959 (1959) have noted that serum acid phosphatase levels appear to be elevated in patients with Gaucher's disease.Due to the inherent difficulties in developing a specific substrate for prostate acid phosphatase, several researchers have developed immunochemical methods for the detection of prostate acid phosphatase. However, the previously reported immunochemical methods have drawbacks of their own which have precluded their widespread acceptance. For example, Shulman et al., in Immunology 9_3: 474 (1964) described an immunodiffusion test for the detection of human prostate acid phosphatase. Using antisera prepared from a prostatic fluid antigen obtained by rectal massage from patients with prostatic disease, no cross-reactivity precipitin line was observed in the double diffusion technique against extracts of normal kidney, testicle, liver and lung. However, this method has the disadvantages of limited sensitivity, even with the large amounts of antigen employed, and of employing antisera which may cross-react with other, antigenically unrelated serum protein components present in prostatic fluid.Foti et al. reported in Cancer Research ^5: 2446 (1975) the use of radioimmunoassay (RIA) techniques for measuring serum acid phosphatase. Using a similarly obtained prostatic fluid antigen for the production of antisera, preliminary clinical trials showed that patients having advanced prostatic cancer exhibited elevated acid phosphatase levels. The RIA technique is extremely sensitive, but takes several days to perform and requires sophisticated equipment and highly trained personnel. This method has the further inherent disadvantages of a short useful shelf life of only about one month for the reagents employed due to the brief half-life of radioactive iodine 125 and of a false positive rate of about 14% as reported recently in Clin. Chem. ___ .- 95-99 (1977).Thus, there is still a need for simple, reliable, sensitive and specific reagents and techniques to measure prostatic acid phosphatase with acceptable diagnostic accuracy and without the aforementioned difficulties of the prior art. The present, invention fills such needs.Disclosure of the InventionIt is a general object of the present invention to provide an improved diagnostic reagent suitable for the immunochemically specific detection of cancerous prostatic serum phosphatase isoenzyme patterns.Another object of this invention is to provide a rapid and simple method for the early detection of prostatic cancer.A further object of the present invention is to provide a highly specific and sensitive immunochemical technique and reagents useful in the early detection of prostatic cancer An additional object of this invention is to provid an immunochemical test and kit for the early detection of prostatic cancer.Upon further study of the specification and appended claims, other objects, features and advantages of this invention will become apparent to those skilled in the art.Best Mode for Carrying Out the Invention Briefly, the above and other objects, features and advantages of the present invention are attained in one aspect thereof by providing immunoprecipitating antisera which are highly specific to cancerous prostatic acid phosphatase isoenzyme patterns and which do not immunochemically cross-react with acid phosphatases originating from other tissues.In a second aspect of the present invention, there is provided an immunochemical method for the detection of cancerous prostatic acid phosphatase isoenzyme patterns which exhibits high sensitivity, good specificity and substantially no false positive results in the detection of prostatic cancer.According to the present invention, antigenic preparations from cancerous human prostate tissue or fluid are purified to obtain a purified prostatic acid phosphatase preparation consisting essentially of the isoenzymes associated with prostatic cancer. These antigenic preparations are employed for immune-logical vaccination and diagnostic procedures, particularly for immunoprecipitin testing. While not wishing to be bound by any theory of the present invention, it is postulated herein that greatly improved antigenic preparations are obtainable by isolating and purifying prostatic acid phosphatase from cancerous human prostate, so that the characteristic isoenzyme pattern thereof corresponds to that associated with carcinoma of the prostate rather than the isoenzyme pattern of normal prostate tissue or fluid, which have generally been employed in the prior art. Furthermore, it has now been found that the human prostatic acid phosphatase isoenzymes associated with prostatic cancer appear to have different sites for antibody binding and for enzyme activity. Therefore, immunoprecipitin antigen-antibody complexes such as are obtained in immunoelectrophoresis continue to exhibit the enzyme activity characteristic of prostatic acid phosphatases so that a combination of immunological and enzymatic techniques can now be applied for the detection of acid phosphatases, thereby greatly enhancing the combined sensitivity and specificity of previous methods. This is the basis for the development of both the counterimmuno- electrophoresis technique as well as the solid-phase fluorescent immunoassay of this clinically important enzyme.Anti-prostatic acid phosphatase not only separates prostatic acid phosphatase from other phosphatases and serum proteins, but also stabilizes the enzyme. Subsequently, the activity of prostatic acid phosphatase is measured by the hydrolytiσ product, which can be quantitated with great sensitivity. Preferably, either the prostatic acid phosphatase substrate or its corresponding hydrolytic product is fluorogenic, so that the enzyme activity can be readily determined with great sensitivity by spectrofluorometric techniques. Suitable such substrates are well known in the art and described, e.g. by M. Roch in Fluorometric Assay of Enzymes appearing in Methods of Biochemical Analysis 7: 189 - 285 (1969) and by Lowry et al. in A Flexible System of Enzymatic Analysis published in New York by Academic Press, Inc. (1972) , the contents of which are incorporated by reference herein. Presently preferred are substrates whose hydrolytic products are chromogenic while the unhydrolyzed substrate is not. Such compounds are likewise well known in the art and include but are not limited to alpha-naphthyl phosphate; beta-naphthyl phosphate; 4-methyl-umbelliferyl phosphate; and 6-bromo- 2-hydroxy-3-naphtholyl-o-anisidine phosphoric acid. Human prostatic . carcinoma tissues are minced, homogenized, dialyzed and concentrated using conventiona tissue extraction techniques. The crude extract i separated from extraneous water-insoluble cellular material and other proteins and then precipitated, e.g. b salting out such as with ammonium sulphate. Preferably, the partially purified isoenzymes are passed through phosphorylated* ion exchange column to increase th specific activity of the prostatic acid phosphatases. Th activated enzyme is dialyzed and acid phosphatase elute in a major and minor fraction, with the major fractio (having greater specific enzyme activity) being subjecte to further purification, e.g. by gel chromatography.The molecular weight of prostatic acid phosphatase ha been determined to be around 100,000. The other protei component, with a molecular weight of around 65,000 daltons, was not included in the, present study. Becaus acid phosphatase is biochemically a glycoprotein, one ca alternatively use an initial affinity chromatography, e.g. of Con A-Sepharose, for its purification. Subsequen chromatographies on a DEAE ion-exchange column an Sephadex G-100 gel filtrations result in a homogeneous protein preparation exhibiting acid phosphatase activity. This purified protein preparation was used for Experiment 11-24 in this study. For the _ preparation of immunogens suitable for preparing diagnostic antibodies against the carcinoma- associated isoenzyme pattern in laboratory animals, conventional vaccine preparation techniques can be used. Preferably a non-antigenic adjuvant, e.g. alum, Freund's complete adjuvant, saponin, a quaternary ammoniu surfactant, an alkyl amine, etc. is admixed with th purified isoenzyme proteins in a suitable immunologicall acceptable, non-antigenic carrier and the resultan mixture can be sterilized, e.g. by filtration.The vaccine can be administered parenterally followin regimens already known for immunization with other proteins to stimulate the formation of immunoprecipitating antibodies, with the primary inoculation being preferably followed up by at least one additional injection one to ten weeks later. Good results have been obtained in rabbits using four booster injections at two week intervals one month after the primary immunization. The protein content per injection in rabbits, goats and other mammals can be varied, but is generally about 100 micrograms of protein per kg. of body weight. The antibodies can be collected and worked up using methods well known to those skilled in the art of immunochemistry, and provide a useful reagent for the immunological detection of prostatic acid phosphatase cancerous isoenzyme patterns in a variety of immunochemical procedures, e.g., immunoprecipitin, fluorescent antibody, serum neutralization, etc. Such antibodies are useful as a control reagent in the diagnostic test for prostatic cancer described more particularly below. While in principle applicable to a variety of immunological tests currently in use , immunoprecipitin and fluorogenic tests represent a presently preferred embodiment and accordingly will be discussed in detail.The simplest immunoprecipitin test involves capillary tube precipitin testing, wherein separate antibody and antigen solutions are allowed to react at a common interface in a capillary tube and a positive reaction is indicated by the formation of a precipitate at the interface. This method is relatively insensitive and inaccurate due, inter alia, to unavoidable diffusion of the two solutions across the interface, and furthermore the final test results cannot be preserved.Agar gel diffusion is the simplest method which avoids these drawbacks. A solution of the antigen (or serum sample) is placed in a central well punched in a continuous agar gel and appropriate dilutions of the serum containing antibodies thereto are placed in wells concentrically surrounding the center well. A positive reaction is noted by the formation of the precipitin lin between one or more of the concentric wells and th central well. This method is relatively insensitive an fairly slow, requiring 1 to 4 days to read the tes results.Radioimmunoassay (RIA) , e.g. radioimmunoprecipiti tests, are extremely sensitive (by several orders o magnitude over older methods) but take several days t perform and require sophisticated equipment and highl trained personnel not always widely available. Countercurrent electrophoresis is a widely use immunoprecipitin method which takes only about an hour t perform and which is considerably more sensitive than aga gel diffusion. Reactive components are placed in opposin wells cut into an agar gel and a small electrical curren applied thereto, causing both the antigen and the antibod to migrate towards each other. While almost al immunoelectrophoresis is conducted at an alkaline pH of a least 8, it has been found that prostatic cance isoenzymes used in the present invention becom irreversibly denatured at this pH and must be run at. a p of less than 7.0, preferably 6.5 or lower. At pH 6.5 purified prostatic acid phosphatase moves towards th anode, while purified rabbit IgG moves towards th cathode. Therefore, by placing acid • phosphatase in th cathodic well at the cathodic side and rabbit antisera i the anodic well, the enzyme and its antibody meet betwee the wells during electrophoresis. A positive reaction i indicated by the formation of a precipitate at th antigen-antibody interface. Since this test method i reasonably reliable, readily available and inexpensive, i represents the presently preferred embodiment of thi aspect of the present invention. For purposes of immunoelectrophoresis testing, th diagnostic antibody preparation of the present inventio when used without purification is generally diluted wit phosphate buffered saline in a volume ratio of 1:10 t 1:500, generally 1:50 to 1:250, depending on the antibody titer thereof. The limiting factor at the lower end of the range is the degree of distinction achieved in the precipitin lines, which is a function of the antibody content in the total protein present. Purified antibody preparations can of course have lower total protein concentrations, and the protein content of even the unpurified preparations can be varied to sϋϊt the particular immunochemical test to be employed, the optimal amounts being determined, e.g. by testing simple serial dilutions. In a preferred, further aspect of the present invention, circulating prostatic acid phosphatase can now be detected at the nanogram level by immunochemical techniques, preferably by protein staining . of the antibody-enzyme precipitin complex. Using the aforementioned antisera specific to prostatic acid phosphatase and coupling this with a conventional staining reagent to detect enzyme activity of the antigen-antibody complex, it is now possible to immunochemically separate the specific prostatic acid phosphatase isoenzyme pattern associated with prostate cancer from a serum sample and to detect it by the enzyme activity thereof.The antigen-antibody complex can be stained by a number of known histoche ical staining techniques, e.g. fluorescent antibody, thymolphthalein monophosphate, napthyl phosphates, phosphoric acids, etc. to increase the sensitivity of this method to 10-20 ng/ml of prostatic acid phosphatase protein, which is comparable to that obtained in r ioimmunoassay techniques. Alternatively, one can use radioactive antibody for the assay, which not only provides a better quantitative value but may also further increase the sensitivity of the assay. If desired, a second enzyme, e.g. beta-galactosidase, can be coupled with purified prostatic acid phosphatase antibodies for use in an enzyme-linked immunoassay, e.g. using techniques analagous to those described by Kato et al. in J. Immunol. 116: 1554 (1976) , the contents of which are incorporated by reference herein.In order to c >nserve diagnostic antibodies against the isoenzyme pattern of prostatic acid phosphatase which is associated with prostatic cancer, it is preferable to bind these antibodies onto a water-insoluble support for use in the enzyme assay. Many suitable such supports and techniques for binding proteins thereto are well known in the art and include inorganic as well as organic supports. Presently preferred are those water-insoluble supports which can be activated with a cyanogen halide, preferably cyanogen bromide, prior to the covalent bonding of the antibodies thereto, e.g. as taught by Axen et al. in U.S. Patent 3,645,852, the contents of which are incorporated by reference herein.The presently preferred solid-phase fluorescent* immunoassay technique for human- prostatic acid phosphatase employs this further advantage and primarily involves the immunological specificity of prostatic acid phosphatase and the inherent fluorescent property of alpha-naphthol, the enzyme hydrolysis product of prostatic acid phosphatase. Unlike other - sensitive immunoassay techniques, such as the enzyme-linked immunoassay or the double antibody radioimmunoassay, this technique does not require the application of a second enzyme or antibody.Further, the quantitation of prostatic acid phosphatase in this assay is based upon the catalytic activity of the enzyme and therefore differs from that of radioimmunoassay, which measures the mass of the enzyme protein. The specificity of this assay is provided by the antiprostatic acid phosphatase, raised against the purified enzyme from the prostate, which specifically binds the prostatic acid phosphatase; the assay is further characterized by the fluorescence of enzyme hydrolysis product, which permits quantitation with a very sensitive spectrophotofluorometric technique. It therefore combines an immunological and biochemical as well as a chemical approach to enzyme quantitation. ^&VR( __0M >- WΪP The sensitivity of this solid-phase immunofluorescent assay for prostatic acid phosphatase is 60 pg/ml of serum under the experimental protocol described. If a greater sensitivity is .needed, it can be accomplished by increasing the volume of specimen assayed. The sensitivities of the counter immunoelectrophoresis and the ra ioimmunoassay techniques are 20 and 10 ng/ml, respectively. Immunofluoroassay, therefore, provides a more sensitive tool for serum prostatic acid phosphatase determinations. This procedure is reliable, as supported by reproducibility studies of within-assay and between-assa . The solid-phase IgG (anti-prostatic acid phosphatase)-Sepharose can be reused. Furthermore, this assay, does not require the use of an isotope. The standard curve of this assay extends from 60 pg to 912 ng per ml of specimen, so that it covers a much broader range than the radioimmunoassay.Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative and not limitative of the remainder of the disclosure in any way whatsoever. All temperatures are set forth uncorrected in degrees Celsius; unless otherwise indicated, all pressures are ambient and all parts and percentages are by weight.EXAMPLE 1 Extraction of Crude Material Human prostatic tissues and other human tissues (kidney, lung, liver etc.) were collected during autopsy or surgery. All tissues were used immediately after collection or stored immediately after collection at -75 C. until used. Normal male and female sera were donated by volunteers. Sera of patients with histologically proven prostatic carcinoma and the sera of patients bearing other cancers were obtained from the Roswell Park Memorial Institute and the National Prostatic Cancer Project chemotherapy participating institues; Mount Sinai School of Medicine provided sera from patients with Gaucher 's disease. The clinicial stage of patients with prostate cancer was determined by the system of Whitemore described in Cancer 16_: 1119 (1963) and summarized as follows: Stage A - tumors confined to the prostate and not palpable; Stage B - tumors confined to the prostate but palpable, no metastasis; Stage C - locally invasive tumors, induration extending beyond the capsule of the prostate; and Stage D - distant metastases, e.g. bones or soft tissue.The1, tissues were weighted, minced and mixed with 0.02M sodium .'acetate buffer, pH 5.2 containing 0.1% of Tween 80 (3 ml/g tissue) . Homogenization was carried out with an Omni-mixer. Tissues in the homogenizer were subjected to 5 minutes blending, three times, at a blade speed of 25,000 rpm with intermittent cooling times of 3 minutes. The homogenates were stirred overnight, then centrifuged at 10,000 x g for 20 minutes. The supernatant was dialyzed overnight against 0.02M sodium acetate buffer, pH 5.2. The dialyzed supernatant was concentrated to desired volume in a concentrator fitted with a Diaflo PM 10 ultra-filter under nitrogen pressure. The extracts of other tissues were dialyzed against water for 2 days with 3 changes of water at 12 hour intervals. This entire operation and all other experiments were carried out at 4°C. The dialyzed materials were then concentrated to about 15-30 mg/ml protein.EXAMPLE 2 Initial Purification of Acid Phosphatase The crude extract which was obtained in Example 1 from 130 g of tissue was passed through 0.5 x 6 cm column of agarose: 5*-(p-nitrophenyl phosphate) uridine-2' (3 ') phosphate (commercially available from Miles Laboratories, Elkhart, Indiana) to - remove ribonuclease and otherOΛIPJ proteins. Ammonium sulphate was added to the effluent (containing acid phosphatase) to 75% saturation. After 12 hours, the mixture was centrifuged and the pellet dissolved in a minimum amount of 0.01M phosphate buffer, pH 6.0, and dialyzed overnight against the same buffer.EXAMPLE 3 SpecTfic~Act yrty Ehhancement of Acid Phophatase The solution from Example 2 was passed through 2.5 x 46 cm phosphocellulose column equilibrated with 0.02M phosphate buffer, pH 6.0. Acid phosphatase was not adsorbed on this column, but the specific activity of the enzyme (enzyme activity per unit weight of protein) was increased approximately 60-100% by this step. The resultant effluent was dialyzed against 0.02M phosphate buffer, pH 7.0 and applied onto a 2.5 x 35 cm DEAE-Sephadex A50 column pre-equilibrated with the same buffer. The column was first washed ., with 300 ml of buffer, followed by a convex gradient of 0 to 0.5M NaCl in 0.02M phosphate buffer, pH 7.0 to 6.0 with 400 ml of 0.02 M phosphate buffer pH 7.0 in the reservoir and 200 ml of 0.02 M phosphate buffer, pH 6.0 containing 0.5 M NaCl, in the mixer. Acid phosphatase was eluted out in one. major and one minor fraction.. Only the major fraction with a <■ greater specific enzyme activity was subjected to further purification.EXAMPLE 4 Purification of Activated Acid Phosphatase Eluates containing acid phosphatase were pooled and dialyzed overnight against 0.02M phosphate buffer, pH 7.0. The dialyzed enzyme solution was concentrated by adsorption on a small column (1.8 x 6 cm) of DEAE-Sephadex A50, followed by elution with 0.02M phosphate buffer, pH 6.0. A concentrated solution (20 ml) was applied to a Sephadex G-200 column (3.5 x 106 cm) and the column was eluted with 0.02M phosphate buffer, pH 7.0. Fractions containing the final purified acid phosphatase were pooled and used for further experiments.EXAMPLE 5 Isoelectric Focusing Isoelectric focusing was carried out at 4°C. using Shandon Southern analytic polyacrylamide gel electrophoresis apparatus. Polyacrylamide gels (5 x 70mm) were prepared according to procedures described in the instruction sheet from the Bio-Rad Laboratories. Phosphoric acid (0.02 M)' was used as the anolyte and NaOH (0.01 M) as the catholyte. Samples were mixed with an equal volume of 50% sucrose solution and 50 mu 1 of sample sucrose solution was applied on top of the gels (anode side) . A constant voltage of 120 volts was applied for 20 hours. After electrophoresis gels were stained for acid phosphatase activity using 0.1% alpha-naphthyl phosphate 0.1% fast Garnet GBC salt in 0..1 M ammonium acetate buffer at pH 5.0., EXAMPLE 6 Homogenity of Purified Enzyme Upon polyacrylamide gel electrophoresis, this enzyme preparation was shown to be homogeneous, with a single enzyme activity band overlapping with the protein band. Diffuse bands were observed in the experiment, probably due to the fact that prostatic acid phosphatase is biochemically a glycoprotein. The protein and acid phosphatase activity profiles of the final step of purification on Sephadex G-200 were determined. A symmetrical protein peak (at 280 nm) , exhibiting acid phosphatase activity (at 400 nm) , was obtained. With this modified isolation procedure, a 150-fold purification of enzyme was achieved, which was 50% higher than with the procedure previously described in Cancer Chemotherapy Reports 59: 97 (1975) .OMPI EXAMPLE 7 Simplified Purification of Acid Phospatase From Prostate Tissues 102.5 g of prostatic tissue was homogenized with 308 ml of 0.01% EDTA-0.1% PBS, pH 6.8. The extract was σentrifuged at 28,000 x g for 30 minutes at 4°C. and the supernatant (350 ml) was precipitated with 50-70% ammonium -—sul -ate —The precipitate was dissolved in the starting buffer solution (1 mM each of CaCl, MnCl2 and MgCl2 in 0.1M NaCl, NaOH acetate) and dialyzed overnight against the starting buffer. The solution was centrifuged at 28,000 g for 3 minutes at 4°C. The supernatant (31 ml) was then applied onto a Concanavalin A-Sepharose column (2 x 40 cm) and incubated overnight at 4°C. The unbound proteins were eluted with the starting buffer solution and the bound proteins (primarily acid phosphatase) were eluted with 500 ml of 0.1 M-0.5 'M methyl-alpha-D-manno- pyranoside in starting buffer. The fractions containing acid phosphatase were concentrated to 6.8 ml with an Amicon PM-30 membrane, and this concentration solution was subjected to a DEAE cellulose column (2 x 46 cm) and eluted with a linear gradient 500 ml of 0.2M sodium phosphate pH 7.0-500 ml of 0.02M sodium phosphate pH 6.0. The fractions containing acid phosphatase were again concentrated • to 3.5 ml with an Amicon PM-30 membrane, applied onto a Sephadex G-100 column (2.5 x 96 cm) and eluted with 0.01M citrate buffer, pH 6.0. A homogeneous protein exhibiting acid phosphatase was thus obtained. The relative enzyme activity and purification of acid phosphatase at each step of this procedure is shown in the attached table. BU £ »OMPI.A ° TotalEnzymic Protein Total Enzymic RelativeVol Activity Cone. Protein Activity Specific ActivityStep ml (Unit) (mg/ml) (mgs) (Unit) Activity (fold)Prostate Tissue 350 393- 23.5 8225 137550 16.7(NH4)2S04 Precipitate 31 1861 9.5 294.5 57691 195.8 11.7Con A Column 6.8 3933 19.0 129.2 26744 207 12.4DEAE Column 3.5 •8390 11.5 40.3 29365 729 43 . 7G-100 Column 2.7 4391 3.28 8.8 11855 1338 .7 80 . 2 EXAMPLE 8 Preparation of Antisera Purified prostatic acid phosphatase obtained from • Example 4 was emulsified with an equal volume of complete Freund's adjuvant, and 1 ml of emulsified mixture containing 100 micrograms of protein was injected subcutaneously among ten sites on the back of each of eight female rabbits. Similar preparations were injected into three goats using 3 mg of protein per goat. A booster injection using the same dosage as the primary immunization was given one month later and repeated three times at two week intervals. Collection of antisera started 10 to 14 days after the last injection. Antisera were obtained by drawing the blood directly from the ear vein. The blood was allowed to clot at room temperature and then centrifuged.The antisera are specific to prostatic acid phosphatase. By double diffusion and countercurrent immunoelectrophoresis techniques, using crude acid phosphatase preparations from normal kidney, bladder, bone, liver, spleen, brain and intestine at concentrations of 3 mg protein/ml and 20-500 I.U. (International Units, the number of icromoles of substrate converted per minute per liter of enzyme solution) enzyme activity, no reaction was shown with the antisera. Furthermore, no precipitate formation was observed when the antisera was reacted with normal male or female human serum samples. Antisera absorbed by normal female serum and extracts of these various tissues (at 1 mg/ml each) continued to react with prostatic acid phosphatase preparations and with sera from patients having prostate cancer. The unabsorbed antisera did not cross-react with acid phosphatase of plant (potato) origin. The specificity of the antisera to acid phosphatase was further confirmed by countercurrent immunoelectrophoresis with the reagent antisera replaced by normal rabbit antisera, wherein no precipitin lines were observed. EXAMPLE 9Countercurrent ImmunoelectrophoresisVarious conditions for the electrophoresis were examined. These include the concentration of agar, pH, temperature, current, length of time of electrophoresis, dilution of antisera, size of well and distance between the wells. Detection of the enzyme-antibody precipitin line could not be achieved by regular protein stains (Coomassie solution or Amido Black) , as the concentration of serum prostatic acid phosphatase was too minute to be visualized. The application of enzyme activity staining with 0.1% alpha-naphthyl phosphate and 0.1% fast Garnet GBC salt reagent in O.lM ammonium acetate buffer at pH 5.0 analagous to the Veronal acetate buffer technique described by Barkat in J. Histoσhem. and Cytochem. 9_: 542 (1961) greatly increased the sensitivity of the technique. Many other staining reagents were also successfully employed as shown in the following Table and it appears that any of the known acid phosphatase substrates can be used. The present optimal staining conditions for enzyme activity are reported below.Substrate Staining Agents1. Sodium Glycerophosphate Ammonium Sulfide2. Naphthol-AS Phosphate Fast Violet B Salt3. Alpha-Naphthyl Phosphate Fast Blue RR4. Alpha-Naphthyl Phosphate 5-Chloro-o-toluidine- diazonium salt5. Naphthol-AS-MXPhosphoric Acid Fast Garnet GBC Salt6. Naphthol-AS-Bl PhosphoricAcid Fast Garnet GBC Salt7. ThymolphthaleinMonophosphate Fast Garnet GBC Salt Countercurrent immunoelectrophoresis was performed on plastic mylar sheets (Mylar 6509 13 x 18 commmercially avaiable from Bio-Ware, Inc., Wichita, Kansas) covered with 35 ml of 0.75% (Sigma Chemical Co., St. Louis, Missouri) agarose in 0.05M phosphate buffer at pH 6.5. The same buffer was used in the electrode vessels. Parallel rows of wells, 4 mm in diameter, were cut 5* mm apart in the agarose. Ten microliters of serum was placed in each cathodic well and an equal volume of diluted antisera added to each anodic well. (The proper antibody concentration was determined by electrophoresing serially diluted antibody against 4 I.U. or 0.2 ng of purified acid phosphatase and choosing the lowest concentration of antibody giving a suitable reaction) . The agarose sheet was then placed in the electrophoresis cell, with the ends of the sheet dipping into the buffer in the electrode vessels. A plate of this size can accommodate as many as three double rows containing eighteen paired wells in each row. Thus, 54 samples can .be analyzed on each plate and the two plates can be run simultaneously. The whole procedure can be performed with ease in 6-8 hours.A constant current of 3.2 mamp/cm was applied for 2 hrs. at 4°C. The plate was then stained for 1 hour at 37 degrees C. in 0.1% alpha-naphthyl phosphate and 0.1% fast Garnet GBC salt in O.lM ammonium acetate buffer at pH 5.0. The plate was rinsed in distilled water and the reaction evaluated. A positive result was reported when the serum specimen contained a detectable amount of prostatic acid phosphatase by this method. After evaluation, the plates were air dried at room temperature and stored for future reference.The sensitivity of the assay varied from run to run, depending upon the antisera used. The lowest detectable activity of serum prostatic acid phosphatase using 10 microliter specimens ranged from 0.2 - 0.4 I.U. or 10-20 ng/ml of prostatic acid phosphatase protein. EXAMPLE 10 Clinical Diagnostic ResultsUsing the countercurrent immunoelectrophoresis technique of Example 9, sera from patients with prostatic cancer were examined. In one patient with proven stage A disease, no serum prostatic acid phosphatase could be detected by this method. However, of 20 patients with proven stage B, (6/20 or 30%) gave positive results. As the disease became more severe, the percentage of positives increased; 55% (27/49) of patients with proven stage C and 80% (98/125) in proven Stage p were detectable. None of 19 patients with benign prostatic hypertrophy gave any positive results.In order to determine the rate of possible false positives, serum specimens from 107 normal healthy volunteers and 50 normal age-matched older men were similarly examined; all had negative results. In addition, 87 patients with other carcinomas of the colon, lung, stomach, pancreas and kidney were tested, including seven female patients with metastasized (to bone) breast cancer. Only one of these 87 patients gave a positive result; this patient turned out to have both a primary lung adenocarcinoma and prostate cancer.As previously noted, it has been reported that a significant number of patients with Gaucher 's disease have an elevated serum acid phosphatase activity. Therefore, sera from 12 patients with Gaucher's disease were tested; all gave negative results.EXAMPLE 11 Alternate Purification of Prostatic Acid Phosphatase The supernatant containing the crude acid phosphatase preparation from 102 g of prostatic tissue was brought to 40% saturation of ammonium sulfate with mixing, settled for 3 hr at 0° and then centrifuged at 13,000 rpm for 30 min. The supernatant was adjusted to 75% saturation of ammonium sulfate, mixed, kept at 0° for 3 hr, and• •^BUR __O centrifuged at 13,000 rpm for 30 min at 4°. The precipitate was dissolved in a minimum amount of starting buffer, pH 5.0 (1 mM each for CaCl2, MgCl2, and 0.1 M each for NaCl and CH^COONa) , dialyzed overnight against the same buffer and then centrifuged at 13,000 rpm for 30 min at 4°. The supernatant (30 ml) was applied to a Con A-Sepharose column (2 x 40 cm) and incubated for 24 hr at 4°. The proteins not bound to the column were eluted with starting buffer (Peaks I, II) . The acid phosphatase •and other glycoproteins, bound to Con A, were eluted with a linear concentration gradient of 0.1 to 0.5 M alpha-methyl-D-mannopyranoside with the use of 500 ml of the above starting buffer in each reservoir (Peak III) .The eluate containing acid phosphatase (Peak III) was dialyzed against 0.02 phosphate buffer, pH 7.0, for 18 hr and concentrated to 3 to 4 ml with a Diaflo PM-10 membrane ultrafilter. This solution was applied to a DEAE-cellulose column (2 x 46 cm), equilibrated with 0.02 M phosphate buffer, pH 7.0, and eluted with a linear gradient of 0 to 0.5 M NaCl in 0.02 M phosphate buffer, pH 7.0 to 6.0. Three fractions exhibiting acid phosphatase activity were obtained (Fractions I, II and III) . The Fraction (Tubes 79 to 94) that contained the major protein peak was further purified by being passed through a Se'phadex 6 - 100 column (2.5 x 96 cm) and eluted with 0.01 n citrate buffer, pH 6.0. Acid phosphatase was separated into 1 major and 1 minor fraction. The first (major) fraction, containing the acid phsophatase with a molecular weight of 100,000, was rechromatographed on Sephadex G-100 and a homogeneous preparation was obtained. This purified acid phosphatase preparation was used for further experiments.EXAMPLE 12 Disc Electrophoresis on Polyacrylamide Gel Disc electrophoresis was performed by the technique described by Davis in Ann. N. Y. Acad. Sci. 121: 404-427 (1976) in a standard 7.5% polyacrylamide gel. Twenty-fiv micrograms of purified enzyme, containing 25% of sucros to increase the density of the tested solution, wer applied to the top of a 5 x 70 mm polyacrylamide ge column. Electrophoresis was carried out in 0.05 Tris-HC buffer, pH 8.3, at 4 , with a constant current of ma/tube for 1 hr. After electrophoresis, the gels wer pushed out of the glass tubes and the protein was detecte by staining (30 min) with 0.1% Coomassie blue R-250. Th gel was destained with 5 to 10% methanol by volume. Th enzymatic activity of acid phosphatase was detected b staining with 0.1% alpha-naphthyl phosphate-0.1% Fas Garnet GBC salt in 0.1 M ammonium acetate buffer, pH 5. and the stains in the gels were then scanned.EXAMPLE 13 Assay of Enzyme ActivityAcid phosphatase activity in the chromatographi fractions was determined by the method of Babson an Phillips described in Clin. Chim. Acta 13_: 264-26 (1966) . This method uses alpha-napthyl phosphate as th substrate; the hydrolyzed product, alpha-napthol, forms stable colored complex with Fast Red Salt B in an alkalin condition. The absorbance was measured at 588 nm. One I of acid phosphatase activity is defined as the amount o enzyme in 1 liter of .sample that will hydrolyze th substrate at a rate of 1 micro mol/min.Determination of Protein Concentration: The method o Lowry et al. described in J. Biol. Chem. 193: 265-27 (1951) was used, with bovine serum albumin used as th standard.Preparation of Antisera: The anti-prostatic aci phosphatase serum was raised by injecting the purifie enzyme and a complete Freund's adjuvant into femal rabbits as previously described in Investigative Urolog 15: 319-323 (1978) . EXAMPLE 14 Purification of Anti-Prosatic Acid Phosphatase IgGThe method described by Harboe and Ingrid in Scand. J. Immunol. Suppl. 1: 161-164 (1973) was used. Briefly, rabbit anti-prostatic acid phosphatase serum (20 ml) was added to 10 ml saturated ammonium sulfate and thoroughly mixed. The mixture was kept in 0° for 3 hr and centrifuged at 2,000 rpm for 30 min; the precipitate was dissolved in sodium phosphate buffer, pH 6.3, and then dialyzed against the same buffer for 24 hr at 4°. The dialyzed solution was applied to a DEAE-cellulose column (1 x 40 cm) and eluted with 0.0175 M sodium phosphate buffer, pH 4.3. The IgG antibody eluted at the first protein peak.Conjugation of purified antiprostatic acid phosphatase IgG sepharose 4B was carried out according- -to the manufacturer's recommended procedure (Pharmacia Fine Chemicals of Uppsala, Sweden) . The CNBr activated sepharose 4B (Ig) was washed and reswelled on a centered glass filter with one mM HC1. The purified antiprostatic acid phosphatase IgG (5 to 10 mg protein per ml gel) was dissolved in 0.1 m NaHC03 buffer pH 8.5 containing 0.5 m NaCl and mixed with CNBr activated sepharose 4B gel suspension, end over end, for 2 hours at room temperature. After incubation, the excess IgG was removed by means of the coupling buffer. The remaining active groups on Sepharose 4B were blocked by adding 1 M monoethanolamine solution, pH 9.0 (5 ml), with gentle mixing for 2 hr at room temperature. Finally, excess blocking reagent was removed by washing first with acetate buffer (0.1 M, pH 4.0) containing 0.5 M NaCl and then with the coupling buffer. This IgG-Sepharose 4B conjugate was further washed with PBS and stored at 4 until used. This procedure resulted in coupling of about 98% of the IgG to the CNBr-activated Sepharose 4B, as determined by measuring immunoglobulin concentration before and after the coupling reaction by spectrophotometry at 280 nm.IJU EATOMPI k r-4, WIP0 EXAMPLE 15 Reactivity of IgG-Sepharose-bound Acid Phosphatase The reactivity of IgG-Sepharose-bound acid phosphatase was studied as follows. Purified acid phosphatase (0.2 ml in PBS) was incubated with IgG-Sepharose (200 microliters) at room temperature for 2 hr; the resulting Sepharose IgG-acid phosphatase was washed with PBS 3 times. The Sepharose-IgG-acid phosphatase was kept at 4°. Another aliquot, 0.2 ml of acid phosphatase, was also left at room temperature for 2 hr and then kept at 4°. Aliquots of 20 microliters each were taken at 8 hr intervals and assayed for enzyme activity. Twenty microliters of specimen were mixed with 1 ml of substrate (see below) and incubated at.37 for 15 min. The reaction was stopped by adding 0.1 M NaOH (2.5 ml), and the hydrolyzed fluorogenic product, alpha-naphthol, was measured with a spectrophotofluorometer.EXAMPLE 16 Solid-Phase Fluorescent Immunoassay Patient's serum (50 microliters) or prostatic acid phosphatase was incubated with IgG-Sepharose 4B (50 microliters) in polystyrene tubes (8 x 75 mm) in PBS for 2 hr at room temperature and then overnight at 4°. The prostatic acid phosphatase was bound to the IgG on the Sepharose 4B. After centrifugation and washing - of the precipitate 3 times with PBS, 1.0 ml of 3 mM alpha-napthyl phosphate (substrate) in 0.2 M citrate buffer, pH 5.6, was added to the acid phosphatase-IgG-Sepharose 4B, and this was incubated for 1 hr at 37°. The supernatant (0.8 ml) was transferred to a new tube containing 2.5 ml of 0.1 M NaOH. The enzyme activity was determined by an Aminco spectrophotofluorometer, with excitation at 340 nm and emission at 465 nm. A standard curve was established with various concentrations of purified acid phosphatase under identical experimental conditions, and the quantity of prostatic acid phosphatase in patients' serum was determined from the standard curve. 'OMPI EXAMPLE 17 Recycling of IgG-Sepharose 4B After the enzyme activity was measured, the prostatic acid phosphatase which bound to the IgG-Sepharose 4B was dissociated by the use of 5 M guanidine-HCl, pH 8.5,. at room temperature for 30 min. The guanidine-HCl and prostatic acid phosphatase were removed by washing with PBS overnight. The dissociated and reactivated IgG-Sepharose can be reused for at least 2 more experimental runs.EXAMPLE 18 Homogeneity and SpecificityThe human prostatic acid phosphatase was purified to homogeneity by the procedure described above. After a series of chromatographies on a Con A affinity column, a DEAE ion-exchange column and Sephadex G-100 gel filtration, a symmetrical protein peak exhibiting acid phosphatase activity was obtained. The homogeneity of the purified protein was confirmed by disc polyacrylamide gel electrophoresis, which demonstrated a single protein band superimposed on the enzyme activity band. The molecular weight of the prostatic acid phosphatase was estimated to be 100,000 by gel filtration by the use of Sephadex G-200. With this procedure, an 85-fold purification and 38% recovery of the activity was achieved.The anti-prostatic acid phosphatase serum, when reacted with prostatic acid phosphatase, gave a single precipitin line on gel diffusion when stained for both protein and acid phosphatase activity. Similarly, after immunoelectrophoresis, only a single arc was observed when stained for protein and enzyme activity against purified prostatic acid phosphatase or crude extract of prostatic tissues. The antiseru did not show any immunological cross-reactivity with the acid phosphatases extracted from other human tissues such as liver, kidney, intestine, lung, etc. The anti-prostatic acid phosphatase IgG fraction was purified from the antiserum and conjugated to CNBr-activated Sepharose 4B. The IgG (anti-prostatic acid phosphatase)-Sepharose 4B was then used to specifically bind the prostatic acid phosphatase.EXAMPLE 19 Reactivity of IgG Bound Acid Phosphatase The enzyme activity of acid phosphatase was studied with and without binding to IgG (anti-prostatic acid phosphatase)-Sepharose 4B. The acid phosphatase which bound to IgG-Sepharose exhibited enzyme activity; furthermore, no loss of the enzyme activity was demonstrated for 48 hr whereas the free acid phosphatase (not bound to IgG-Sepharose) lost about 64% of its enzyme activity during the same 48 hr period and 87% of activity after 96 hr. These results indicate that the IgG-Sepharose-bound acid phosphatase retained its catalytic reactivity for at least 48 hr under these experimental conditions.EXAMPLE 20 Minimum Amount of Solid-phase (IgG-Sepharose) Required In order to determine the minimum amount of IgG (anti-prostatic acid phosphatase)-Sepharose 4B necessary for the assay, various concentrations of acid phosphatase were incubated with a constant amount of IgG-Sepharose for 2 hr at room temperature and overnight at 4°. The enzymatic activity of the acid phosphatase bound to IgG antibody was determined by the fluorometric technique described above. Results indicated that 50 microliters of IgG (antiprostatic acid phosphatase)-Sepharose (containing 0.28 mg of antiprostatic acid phosphatase-IgG) would bind 45.6 ng of prostatic acid phosphatase. Therefore, a minimum amount of IgG (anti-prostatic acid phosphatase)- Sepharose (0.28 mg of IgG) was used in this solid-phase fluorescent immunoassay in order to measure the serum prostatic acid phosphatase concentration up to 912 ng/ml without diluting the serum samples.EXAMPLE 21 Incubation Conditions for Fluorescent Immunoassay In order to determine the optimal incubation conditions for the solid-phase fluorescent immunoassay, prostatic acid phosphatase was incubated with the IgG-Sepharose 4B under different temperatures and at various time intervals. The enzyme activity was also assayed at different incubation times with the alpha- naphthyl phosphate substrate. The results revealed that incubation first at room temperature for 2 hr and then overnight at 4° afforded the best binding between prostatic acid phosphatase and IgG-Sepharose. The measurement of enzyme activity was best determined at 3*7° for 1 hr.EXAMPLE 22 Sensitivity and Reproducibility of Fluorescent Immunoassay The sensitivity of this immunoassay was verified by performing various triplicate determinations- of prostatic acid phosphatase, ranging from 45.6 ng to 3 pg in 50 microliters of specimen. The prostatic acid phosphatase at 3 pg/50 microliters could be detected by this immunofluorometric assay. This assay procedure was found to be reproducible, as a within-assay standard deviation of 6 pg/50 microliters (10 determinations) and a between- assay standard deviation of 9 pg/50 microliters (3 assays, 3 determinations in each assay) were obtained from a sample of 280 pg/50 microliters, representing a coefficient of variation of less than 4%.EXAMPLE 23 Recycling of Solid Phase Reagents The IgG (anti-prostatic acid phosphatase)-Sepharose, after the dissociation of acid phosphatase from the prostatic acid phosphatase-IgG-Sepharose, can be reused for the assay. Although a slight decrease of sensitivity occurred, it < ould be recycled at least three times without losing any appreciable binding to prostatic acid phosphatase.EXAMPLE 24 Additional Clinical Diagnostic ResultsThe results of an inital application of this newly developed immunofluoroassay in testing sera from patients with prostate cancer and other tumors were determined. The determination of serum prostatic acid phosphatase by this assay from a group of 30 apparently healthy male volunteers resulted in a mean of 5.619 ng/ml with a standard deviation of 2.110. A normal range of 1.399 to 9.839 ng/ml was thus determined. The serum prostatic • acid phosphatase levels from 24 patients with all stages of prostate cancer with studied in this preliminary report. The enzyme was found to be elevated in 4 untreated patients with Stage A disease, in 2 of 5 with Stage B and in 7 of 11 with Stage C who were receiving standard estrogen therapy and/or radiation therapy, and in all 4 patients with Stage D disease receiving chemotherapy. On the other hand, the serum prostatic acid phosphatase levels were in the normal range in all 16 patients with other advanced tumors, such as cancer of the lung, breast, colon, rectum, stomach or pancreas. These 16 specimens were randomly chosen from serum samples that had exhibited a highly elevated level of carcinoembryonic antigen (all had a value of greater than 15 ng/ml) .The preceding examples can be repeated with similar success by substituting the generically or specifically described reaσtants and/or operating conditions of this invention for those specifically used in the examples. From the foregoing description, one skilled in the art to which this invention pertains can easily ascertain the essential characteristics thereof and, without departing from the spirit and scope of the present invention, can make various changes and modifications to adapt it to various usages and conditions.Industrial Applicability As can be seen from the present specification, particularly Examples 10 and 24 thereof, the present invention is particularly applicable in diagnosing the presence of antigenic isoenzyme patterns associated with prostatic cancer, even at relatively early stages thereof.OMPI,*Ws WIpo | WHAT IS CLAIMED IS:Claim 1: A process for preparing immunoprecipitating antibodies to antigens associated with prostatic cancer, which comprises: a) extracting acid phosphatase isoenzyme forms having an isoelectric ranget pi of 4.1-5.5 from cancerous prostatic tissue or fluid; b) separating said isoenzyme forms from extraneous arrtigenic proteins to obtain a composition consisting essentially of said isoenzyme forms; c) immunizing animals with the resultant purified isoenzyme forms to form antibodies thereto; and d) recovering immunoprecipitating antibodies against said acid phosphatase isoenzyme forms from said animals.Claim 2: A process according to Claim 1, wherein said isoenzyme forms are separated from extraneous antigenic protein material by salting out.Claim 3: A process according to Claim 2, further comprising additional purification by gel filtration.Claim 4: A process according to Claim 2, wherein said isoenzyme forms have a pi range of 4.5-5.0.Claim 5: A process according to Claim 4, wherein said purified isoenzyme forms have a pi of 4.5-4.8.Claim 6: An in vitro composition of matter comprising an immunochemically effective amount of antibodies against the human prostatic acid phosphatase isoenzyme forms having an isoelectric range pi of 4.1 - 5.5 which are associated with prostatic cancer, said composition being substantially free of antibodies against the normal human serum prostatic acid phosphatase isoenzyme forms. Claim 7: A composition according to Claim 6, wherein said isoelectric range is pi 4.5 - 5.0.Claim 8: A composition according to Claim 6, wherein said antibodies are immunoprecipitating antibodies.Claim 9: A composition according to Claim 8, wherein said antibodies are labeled for radioimmunoassay.Claim 10: A composition according to Claim 6, wherein said antibodies are covalently bonded to a water-insoluble support.Claim 11: A method for diagnosing elevated serum acid phosphatase levels associated with the early stages of prostatic cancer, which comprises forming an immunoprecipitin complex between said serum prostatic acid phosphatase isoenzymes and antibodies specific thereto, and detecting the presence of said complex.Claim 12: A method according to Claim 11, wherein the complex is formed by countercurrent immunoelectrophoresis.Claim 13: A method according to Claim 12, wherein the presence of said complex is detected by measuring the acid phosphatase enzyme activity thereof.Claim 14: A method according to Claim 13, wherein said enzyme activity is measured by staining with a colormetric substrate for said acid phosphatase.Claim 15: A method according to Claim 14, wherein said substrate comprises alpha-naphthyl phosphate and fast Garnet GBC salt reagent.Claim 16: A method according to Claim 11, wherein the complex is formed by immunologically reacting said acid phosphatase with anti-prostatic acid phosphatase antibody covalently bound to a water-insoluble column.Claim-17ι: A method according to Claim 16 , wherein the presence of said complex is detected by measuring the acid phosphatase enzyme activity thereof.Claim-18: A method according to Claim 17, wherein said enzyme activity is measured by staining with a colormetric substrate for said- acid phosphatase.Claim-19: A method according to Claim 13-, wherein said substrate produces a fluorogenic hydrolysis product upon reaction with said enzyme and the presence of said hydrolysis product is measured spectrophotometrically.Claim-20: A method according to Claim 19, wherein said substrate comprises alpha-naphthyl phosphate.OM, A>, ~w AMENDED CLAIMS (received by the International Bureau on 12 June 1979 12.06.79))Claim 1: A process for preparing immunoprecipitating antibodies specific to the prostatic acid phosphatase isoenzyme pattern associated with prostatic cancer, which comprises: a) extracting acid phosphatase isoenzyme forms having an isoelectric range pi of 4.1-5.5, a molecular weight of 100,000 daltons and corresponding to the characteristic isoenzyme pattern associated with carcinoma of the prostate from cancerous prostatic tissue or cancerous prostatic fluid; b) separating said isoenzyme forms from extraneous antigenic proteins to obtain a purified composition consisting essentially of the characteristic isoenzyme pattern of the isoenzyme forms associated with prostatic cancer; c) immunizing animals with the resultant purified isoenzyme pattern to form antibodies thereto; and d) recovering said immunoprecipitating antibodies against said acid phosphatase isoenzyme pattern substantially free of cross-reactivity with the characteristic isoenzyme forms associated with a non-carcinogenic prostate, with acid phosphatases extracted from other body tissues and with antigens associated with other carcinomas or Gaucher's disease from said animals.Claim 2: A process according to Claim 1, wherein said isoenzyme forms are separated from extraneous antigenic protein material by salting out.Claim 3: A process according to Claim 2, further comprising additional purification by gel filtration.Claim 4: A process according to Claim 2, wherein said isoenzyme forms have a pi range of 4.5-5.0. Claim 5: A process according to Claim 4, wherein isoenzyme forms have a pi of 4.5-4.8.Claim 6: An in vitro composition of matter comprisin immunochemically effective amount of antibodies against human prostatic acid phosphatase isoenzyme pattern of isoenzyme forms having an isoelectric range pi of 4.1 - which are associated with prostatic cancer, said composi being substantially free of antibodies against the normal h serum prostatic acid phosphatase isoenzyme forms, against phosphatases extracted from other body tissues and aga antigens associated with other carcinomas or Gaucher's diseasClaim 7: A composition according to Claim 6, wherein isoelectric range is pi 4.5 - 5.0.Claim 8: A composition according to Claim 6, wherein antibodies are immunoprecipitating antibodies.Claim 9: A composition according to Claim 8, wherein antibodies are labeled for radioimmunoassay.Claim 10: A composition according to Claim 6, wherein antibodies are covalently bonded to a water-insoluble supportClaim 11: A method for diagnosing elevated serum phosphatase levels in the characteristic isoenzyme pattern the isoenzyme forms associated with the early stages prostatic cancer, which comprises forming an immunoprecip complex between an antigen consisting essentially of said s prostatic acid phosphatase isoenzyme pattern immunoprecipitating antibodies specific thereto which substantially free of immunoprecipitating antibodies against normal human serum prostatic acid phosphatase isoenzyme fo against acid phosphatases extracted from other body tissues against antigens associated with other carcinomas or Gauch disease, and detecting the presence of said complex.BAD ORIGINAL / OMPl Clai 12: A method according to Claim 11, wherein the complex is formed by countercurrent immunoelectrophoresis at a pH of less than 7.0.Claim 13: A method according to Claim 12, wherein the presence of said complex is detected by measuring the acid phosphatase enzyme activity thereof.Claim 14: A method according to Claim 13, wherein said enzyme activity is measured by staining with a colormetric substrate for said acid phosphatase.Claim 15: A method according to Claim 14, wherein said substrate comprises alpha-naphthyl phosphate and fast Garnet GBC salt reagent.Claim 16: A method according to Claim 11, wherein the complex is formed by immunologically reacting said acid phosphatase with anti-prostatic acid phosphatase antibody covalently bound to a water-insoluble column.Claim 17: A method according to Claim 16, wherein the presence of said complex is detected by measuring the acid phosphatase enzyme activity thereof.Claim 18: A method according to Claim 17, wherein said enzyme activity is measured by staining with a colormetric substrate for said acid phosphatase.Claim 19: A method according to Claim 18, wherein said substrate produces a fluorogenic hydrolysis product upon reaction with said enzyme and the presence of said hydrolysis product is measured spectrophotometrically.Claim 20: A method according to Claim 19, wherein said substrate comprises alpha-naphthyl phosphate. STATEMENTUNDERARTICLE19On page 32, Claim 1 has been amended in conformity with the follow portions of the specification as filed:Preamble: Page 6, third paragraph;Subparagraph a): Page 8, second paragraph and p. 6, third paragraph;Subparagraph b) : Page 32, Claim 6;Subparagraph d) :Page 6, third paragraph (substantially no false positive results) ; p. 19, Second paragraph; p. 22, Example 10; p. 27, Example 19; and p. 30, Example 24On page 33, Claims 6 and 11 have been amended in conformance with the aforementioned amendment to Claim 1 (d) .On page 34, Claim 12 has been amended in conformity with page 10, second full paragraph of the specification as filed, while Claims 17-20 correspond to originally misnumbered Claims 18-21. | CHU T; RESEARCH CORP; WANG M | CHU T; WANG M |
WO-1979000489-A1 | 1,979,000,489 | WO | A1 | XX | 19,790,726 | 1,979 | 20,090,507 | new | D01H1 | D02G3 | D01H4, D02G3 | D01H 4/16, D02G 3/34 | A METHOD AND APPARATUS FOR THE PRODUCTION OF FANCY YARN | A method and an apparatus for the production of fancy yarn includes the supply of elongate fancy material pieces (17) by gas under pressure to suction-loaded spinning cylinders (10) which spin the fancy material pieces together with separately supplied basic yarn pieces to form fancy yarn. The fancy material pieces are flung by means of the gas under pressure, which is preferably generated in a jet injector (14), against a screen (7) which is located in the region of the nip between the spinning cylinders. Elongate fancy material pieces which have become rolled together during transport to the screen (7) are straightened out after impingement against the screen (7) by the suction prevailing in the nip of the spinning cylinders (10) whereby the fancy material pieces are given the desired elongate form in the fancy yarn. | A METHOD AND APPARATUS FOR THE PRODUCTION OF FANCY YARNThe present invention relates to a method and an apparatus for the production of fancy yarn in accordance with the preambles to the main claim and the side claim, respectively The basic concept in a known method for the produc¬ tion of fancy yarn is that the fancy material is thrown into the nip between two rotating yarn spinning cylinders which spin the loose basic yarn twist, the fancy mate¬ rial being admixed to the basic yarn twist. While this method is suited for the production of fancy yarn in which the fancy material serving to pro¬ vide the finished yarn effect is of particulate or spheroid shape, it is not suited for the production of fancy yarn in which the fancy material is to have elongate form, since it has proved that such elongate facy material pieces, on introduction to the cylinder nip, often roll up into balls and are fixed in this shape on being spun together with the basic twist, so that the finished fancy yarn displays unsightly knops of fancy material. Alternatively, the fancy material might not, on being spun together with the basic twist, be properly spun into the twist, with the result that the fancy material comes loose when the yarn is woven. Furthermore, it is difficult to realize a reproducible fancy yarn with this prior art method, that is to say a yarn in which the fancy material lies consistently in desired positions in the yarn.For avoiding these disadvantages in the above-discus¬ sed known method, the present invention has realized a method and an apparatus which permit the production of fancy yarn with elongate fancy pieces in the basic yarn twist and which permit fancy yarn reproduction. This method and this apparatus have the characteristics disclosed in the main claim and side claims, respectively, but advan- tageous embodiments possesses the characteristics disclosed in the subclai s.The invention will be described in greater detail below with reference to the accompanying drawing. Fig. 1 is a schematic illustration of an apparatus according to the invention in an open end type spinning frame. Fig. 2 schematically illustrates a screen with an injec¬ tor at a yarn spinning cylinder. Fig. 3 illustrates the effect of the apparatus according to the invention on the fancy material.Fig. 1 shows an open end machine (DREF) for yarn production, together with an apparatus according to the invention for the production of fancy yarn. Pairs of licker-in rollers 1, 1', drawing rollers 2, 21 and supp- ly rollers 3, 31 advance the card web 4 for yarn pro¬ duction to an opening cylinder 5 with saw tooth fittings (not shown) for loosening or opening the card web to discrete flocks or fibres which, by means of guide plates 6, 7, 8, and with the assistance of compressed air from a compressed air-supply conduit 9, are fed to the nip between two elongate spinning cylinders 10 which rotate in the same direction and which are pro¬ vided with a perforated outer surface. Suction conduits 11 discharge into the cylinders 10 for orientation of the web or basic fibre material in the nip between the cylinders. In this nip, the oriented fibres and flocks are twisted to form yarn which is led out from the nip in the longitudinal direction of the cylinders by means of two discharge rollers 12, 12' (Fig. 2) to a yarn cop or bobbin 13.For the introduction of an effect into the basic material such as material of the same colour as, or other colour than the basic material, the present inven¬ tion calls for a fancy material-supply jet injector 14 directed towards a screen which, advantageously but not necessarily, may consist of the surface of the guide plate 7 facing away from the opener cylinder 5. The fancy material which consists of, for example, fancy material 40 dispersed to elongate pieces or flocks/- fibres, is supplied to the injector by means of a conduit 15 under the action of suction from the in- jector, whose suction-creating pressure-gas hose is designated 16. Thus, the elongate fancy material pieces are thrown against the above-mentioned surface of the guide plate 7, the area of impingement being disposed substantially in the region of the suction effect from the suction conduits 11. The result of this arrangement is that the flocks and fibres 17 of the fancy material which arrive at the plate 7 in bundled or knopped state are, after impingement against the plate 7, substantially straightened out (Fig. 3) to their elongate form by the force from the suction from the nip between the cylinders 10 and arrive, in substantially straightened form, at the nip between the cylinders where they, still in the straigt- tened condition, are twisted together with the basic yarn material emanating from the opener cylinder 5 and are conveyed, entwined together with the basic yarn twist to the discharge roller 12, 12' and the cop or bobbin 13.The straightening out effect on the fancy material pieces after impingement against the plate 7 probably depends upon the instantaneous arrest experienced by the fancy material on impingement against the plate 7 so that the suction from the cylinder nip can make itself felt for the straightening-out operation (Fig. 3) . In any event, it has not been possible to observe any straightening-out effect on the direct blowing-in of elongate fancy material into the suction-loaded nip between the spinning cylinders, the fancy material pieces being instead incorporated into the basic yarn twist in knops rather than straightening-out pieces. Advantageously, the injector 14 is swingably disposed in the longitudinal direction of the spinning cylinders (Fig. 2) and, for example, pivoted on the plate 7 by means of a holder 18 so that it can supply the fancy material to the spinning cylinders at an optional position of the twist-imparting length of the cylinders via the plate 7. On supply of fancy material at the beginning ' of the twist-imparting length, the fancy material is mixed with the still quite loosely composed basic twist .so that a mingled effect is obtained. On the other hand, on supply of the fancy material towards the end of the twist-imparting length, a core of basic yarn twist will be obtained surrounded by the fancy material which is bonded to the basic yarn twist by means of relatively few basic yarn twist fibres so that the appearance of the fancy material is dominant at those places in the finished fancy yarn where the fancy material is located. Two pairs of rollers 19, 19' and 20, 20' are provided for realizing elongate fancy material pieces for supply to the injector, the rollers in each pair being, by means of a pendulum arm 21, spring-loaded towards each other and the lower rollers 19' and 20', respectively, being driven by means of motors 19 and 20 . The basic fancy material such as fancy ribbon or roving is added to the rear roller pair 19, 19' and drawn and divided into elongate pieces by means of the forward or drawing roller pair 20, 20'. The discrete fancy material pieces are caught by the suction conduit 15 of the injector for supply to the injector 14.For optional distribution of the fancy material in the basic twist, the lower roller 20' in the forward roller pair 20, 20' is advantageously connected to its motor 20 by the intermediary of a magnet switch 22 which receives current pulses from a programming mecha¬ nism operated by means of, for example, a magnetic tape or punched tape. The signals from the programming mecha¬ nism are operative to actuate the magnet switch and there- by to occasion driving of the rollers 20, 20' and - with the rollers 19, 19' in continual operation - to influence the length and frequency of the fancy materialOΛ'.PI• ''- pieces. By variation of the ratio between the speeds of the rollers 19, 19' and 20, 20' (which may be realized by the utilization of motors whose speed may be step- wise or steplessly variable) the thickness of the fancy material pieces may also be varied.It should be clear to the skilled reader that the apparatus according to the invention permits introduc¬ tion into the basic twist of mutually different fancy materials, a desired number of programme-controlled fancy material-producing mechanisms being connected to the suction conduit 15 of the injector 14.The method and apparatus according to the invention may also be utilized when the open end machine is pro¬ vided with a paradise set, a screen according to the invention being fixedly mounted substantially horizon¬ tally between the paradise device (the rotary vane) and one of the spinning cylinders, the edge portion of this screen located close to the nip between the spinn¬ ing cylinders being bent downwardly into the nip. The fancy material pieces are flung against the underface of the screen and, under the action of the suction in the cylinder nip, are guided by this underface into the nip. | CLAIMS1. Method of producing fancy yarn, in which method • basic yarn material is formed to basic yarn twist in the nip between rotating spinning cylinders, the nip being subjected to a partial vacuum, and fancy material pieces being introduced into the nip in order to be in¬ cluded in the basic yarn twist, characterized in that the fancy material pieces, within the region of said partial vacuum, are flung against a screen for further conveyance to the nip. 2. Method according to claim 1, characterized in that the fancy material pieces are elongate.3. Method according to claim 1 or 2, characterized in that the fancy material pieces are flung against said screen by means of a jet injector which is supplied with said pieces by means of the suction conduit of the in¬ jector.4. Method according to any one of claims 1-3, characterized in that the frequency, length and thick¬ ness of the fancy material pieces in the fancy yarn are adjusted by means of a programming mechanism which is operative to influence the driving of fancy-material- -drawing rollers which create the fancy material pieces.5. Apparatus for carrying out the method according to claim 1, the apparatus including two spinning cylin¬ ders (10) for yarn spinning, means (11) for realizing a partial vacuum in the nip between the cylinders, and means for supplying basic yarn material to the nip, characterized by a screen (7) in the proximity of said nip, and by means (14) for flinging, v/ith the assistance of gas under pressure, fancy material pieces against the screen.6. Apparatus according to clam 5, characterized in that said means (14) consists of a jet injector (14) with a suction conduit (15) supplying the fancy material pieces.7. Apparatus according to claim 5 or 6, characterized in that the screen (7) consists of a surface on a guide ' plate which is disposed to guide, with its opposite surface, the basic yarn material to said nip.8. Apparatus according to any one of claims 5-7, characterized in that a programming mechanism is operative to control the driving of rollers (19, 20) producing the fancy material pieces and connected to said means (14) , for determining the length, frequency and thickness of fancy material in the fancy yarn. | OLSSON P; PEO TEKNOKONSULT AB | OLSSON P |
WO-1979000493-A1 | 1,979,000,493 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | E02D29 | null | E03B9 | E03B 9/10 | UNDERGROUND FIRE HYDRANT FRAME AND COVER | A frame (7) and cover (8) for an underground fire hydrant (29) in a highway (14), preferably at an inter-section, and by means of which the fire hydrant is rendered readily accessible for use. The cover (8) includes reflective knobs (28) on its upper surface. Heating elements (32) are provided on the under surface of the frame (7) which also has a depending lip (33) from which moisture can drain. | Description Underground Fire Hydrant Frame and CoverSummaryAmong the primary objects of the invention are to provide a fire hydrant which cannot be damaged by being struck by vehicles; which can be located in the center of a street where burning or falling structures cannot hamper its use; which will afford more curb parking space; which can be utilized by two pumpers where sufficient water supply is available, and which can be more readily kept available in freez¬ ing weather.Another object of the invention is to provide a fire hydrant cover and frame which will not interfere with the movement of vehicular traffic over the cover and which can be readily located at night.Various other objects and advantages of the inven¬ tion will hereinafter become more fully apparent from the folloving description of the drawing, illustrating presently preferred embodiments thereof, and wherein: BRIEF DESCRIPTION OF THE DRAWINGFIG. 1 is a perspective view from above of the frame and cover located in a highway;FIG. 2 is a similar view showing a slightly modi- fieden.boair_.ent of the cover,FIG. 3 is a top plan view on a reduced scale show¬ ing the frame and cover located in the center of a highway intersection;FIG. is an enlarged vertical sectional view taken substantially along a plane as indicated by the line --4of FIG. 3, and showing the frame and cover in place above a conventional fire hydrant, andFIG. 5 is a sectional view taken substantially along the line 5--5 of FIG. 4. _ ? .DESCRIPTION OF THE PREFERREDEMBODIMENTReferring more specifically to the drawing and with reference to FIGS. 1, 3, 4 and 5, the fire hy¬ drant frame and cover in its entirety and constitu¬ ting the invention Is designated generally 6 and com¬ prises a frame 7 and a cover 8. A rectangular con¬ crete or masonry supporting structure 9, composed of side walls 10 and end walls 11, lines a pit 12 in the earth 13 and rests on the bottom of the pit, as seen in FIG. 4. Pit 12 opens upwardly through a portion of a highway 14 in which the upper part of the support¬ ing structure 9 is embedded below the highway surface 15. The upper part of the opening 12 accomodates the frame 7 which is rectangular and rests on the top portion of the supporting structure 9. Said frame 7 fits snugly in the top portion of the opening 12 and is of a thickness such that its top surface is flush with the top surface 15 of the highway.The frame 7 has a large oval shaped opening 17 and is provided with a ledge 18 surrounding the open¬ ing 17 and is disposed below the level of the top sur¬ face 19 of the frame 7. Frame 7 has a downwardly and inwardly inclined or bevelled continuous surface 20 extending from its top surface 19 to the ledge 18.The cover 8 is oval shaped and has a bevelled sur¬ rounding surface 21 of a proper size and shape to con¬ formably fit the bevelled surface 20, when a marginal portion of the underside of the cover 8 is resting on the ledge 8. The cover 8 is of a thickness such that its upper surface 22 is disposed substantially flush with the upper surface 19 when the cover is resting on the ledge 18.Cover 8 has recesses 23 near the ends thereof to accomodate conventional inverted U-shaped handles 24 the depending legs 25 of which extend slidably through openings 26 which communicate with the re¬ cesses 23 and with the underside of the cover 22. The lower ends of the legs 25 are turned outwardly, as seen at 27, toprovide abutments to engage the underside of the cover 22 to limit the extent that the handles 24can be raised without lifting the cover 22. The cover or lid 8 has a plurality of hemispherical knobs 28 which protrude from its upper surface 22. The knobs 28 are spaced from one another and form a rect- - angle, as seen in FIG. 1. The knobs 28 are coated with a material which will reflect the head-light rays of vehicles to enable the cover 8 to be readily located at night.A conventional fire h}7drant 29 extends upwardly in¬ to the pit 12 and is located within the structure 9, beneath the frame and cover 6. The hydrant has two outlets enabling it to be utilized simultaneously by. two pumpers.Electrical conductors 30 lead into the enclosure 9 through an opening 31 in one wall thereof and connect with an electric heating element 32 which is secured to the underside of the frame 7, around the opening 17, for heating said frame and cover 8 in subfreezing weather, to keep the frame and cover free of ice and snow and accessible for use under any weather condition. The underside of the frame 7 has a depending lip 33 from which moisture can drain without coming into con¬ tact with the heating element 32. A heat lamp, not shown, can be substituted for the heating element 32.FIG. 2 shows a slightly modified form of the lid or cover, designated 8a, and wherein the knobs 23a are arranged in the form of a circle. Knobs 23a otherwise correspond to the knobs 28 and the lid or cover 8a otherwise corresponds with the lid or cover 8. Various other modifications and changes are contem¬ plated and may be resorted to without departing from the function or scope of the Invention. | CLAIMSI claim as my invention1. A closure for the open top of a pit containing an undergraound fire hydrant comprising a frame adapt¬ ed to rest on and be supported by a part of the pit with the upper surface of said frame flush with a sur¬ rounding highway surface, said frame having a large opening, and a cover having a marginal portion shaped to fit in said recessed portion of the frame for' clos¬ ing the frame opening, said cover being of a thickness such that its upper surface is disposed substantially flush with the upper surface of the frame when the cover is supported by the frame, an electric heating element secured to the underside of the frame around the opening thereof for heating the frame and cover to prevent the accumulation of ice and snow en the upper surface thereof, and said frame having a depending lip surrounding the opening and disposed between said heating element and the opening to protect the heating element from moisture draining through the opening.2. A closure as in claim 1, said cover having a plurality of rounded knobs protruding from its upper surface and provided with a light reflective coating to facilitate locating the cover in the darkness.3. A closure as in claim 2, said knobs being dis¬ posed in spaced apart relationship to one another and in the form of 'a rectangle.4. A closure as in claim 2, said knobs being dis¬ posed in spaced apart relationship to one another and in the form of a circle. | WHITLOCK L | WHITLOCK L |
WO-1979000496-A1 | 1,979,000,496 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | B25D17 | null | B25D1, B25D17 | B25D 1/12, B25D 17/11, B25D 17/24 | ANTI-NOISE IMPACT ELEMENT | An impact element having the effect of elongating the pulse of force in impact tools and devices for chipping, hammering and similar operations, consisting of an element (8) which, for generating the striking motion, is axially moveable as a whole and comprises a driving mass (16) intended to be actuated by a propelling force, and a striking mass (17) located in front thereof relative to the direction of striking, which masses possess a limited freedom of axial movement with respect to each other in that they are coupled together by a stiff spring arrangement, e.g. cup washers (15), extremely hard plastics or gas cushions. | Anti-noise impact elementProblems are caused at a variety of workplaces, such as engineering shops etc., by disturbing and harmful noise from tools of impact type such as, on the one hand, pneumatic chipping hammers, scaling hammers and the like, and on the other hand, manually powered tools such as 5 hammers, sledge-hammers and the like. The present invention is concerned with an impact element for tools and devices of impact type which in its mode of action brings about an acoustically damping elongation of the pulse of force.The collision of two masses (in air) generates a pulse of force the 0 shape of which is a function primarily of the power expended and of the rigidity of the colliding masses. The power expended is dependent primarily on the opposed kinetic energies of the masses and on the duration of the collision. The rigidity depends mainly on the properties of the materials constituting the masses - and the points of the latter 5 involved in the collision - as well as on the area of the colliding faces and the duration of the collision. The usual energy losses are in the form of an air wave, a temperature rise, structure-borne sound vibrations and acoustic wave propagation. Irrespective of the purpose of the collision and of the means by which it is brought about - i.e. 0 irrespective of whether the technical application is chipping, hammering etc., - the pulse of force is the primary factor both with regard to the technical performance and to noise generation. A pulse of force representing 'a' quantify given up by an impact element can be illustrated graphically, as shown in Fig.: 3 5 appended hereto, by a graph with a vertical force axis and a horizontal.^time axis. The curve of the pulse rises, while .moving.along <the time I axis, from zero to a peak value and then falls'back -to itfhϊcK stage the whole of the energy has been given up. The area .enclosed' ,! between the curve and the time axis represents the quantity of energy, 0 given up. Curves 1 and 2 on the graph enclose approximately the same area, i.e. they represent the same amount, of energy. Curve 1 illustrates l a rapid pulse, where the area representing the -energy has a short extension along the time axis and consequently reaches a higher maxiπfum_ along the force axis, while Curve 2 shows a pulse having a greater \ 5 extension in tim'e'and a' lower maximum level of force. In an operatTond n such as the removal of welding scale from sheet steel by means of a pneumatic scaling hammer fitted with a chisel and of conventional type without a pulse elongating device, the curve of the pulse obtained approximates to Curve 1. The high maximum level is advantageous for th40 technical performance, i.e. the working efficiency of the tool, but it also gives a steeply rising and falling curve with a short extension along the time axis, resulting in a high noise level. Thus the problem to be solved is to shape the curve so as to obtain, on the one hand, a adequate maximum level of force and, on the other hand, suitable curve45 gradients with respect to the time axis at all phases of the force cyc so as to achieve both satisfactory technical performance and also acoustic damping.The pulse of force is composed of numerous sinusoidal vibrations which in combination determine ttήe shape of the pulse. By modification50 of the pulse some of the component vibrations can be eliminated or reduced. If certain frequencies are absent from the pulses of force delivered, for example, to a metal plate by a scaling hammer or simila tool, this implies that vibrations of these frequencies will not be excited in the plate (the so-called structure-borne sound) and, furthe55 that the radiated air-borne noise will lack these components. Which frequencies it is most desirable to eliminate or reduce depends on the * o ~ ir. ' ■ ' work being performed. In the case of work with a pneumatic scaling hammer the most troublesome frequencies are generally those between1000 Hz and 4000 Hz. In the case of the impacts of a sledge-hammer on e_ ' ~ - '60 a large metal plate the acoustic spectrum is dominated by lower freque cies.The above-mentioned problem of suitably modifying the shape of t pulse is solved with the impact element of the invention by endowing i with the characteristics specified hereafter in the claims.65 It is a known practice in mechanical pile-driving to use a pile helmet on top of the pile to modify the impact wave or pulse of force transmitted via the ram and the helmet to the pile, with the object of increasing energy efficiency in pile-driving. Attempts have also been made on a similar principle - by placing an elastic, yielding mass suc70 as polyurethane rubber between the impact piston and the chisel shank to modify the form of the pulse in conventional types of pneumatic scaling hammers for the purpose of reducing noise generation. The type of scaling hammer referred to operates with a moving mass in the form of- a piston which strikes against the shank of a chisel mounted in one end75 of the scaling hammer and applied to the workpiece. The striking fre¬ quency is usually between 70 and 100 impacts per second. The pulse of force arises as the piston makes contact with the chisel shank and propagates to the point of the chisel. It takes the form of a wave of compression traveling up into the piston and a tensile wave returning80 down to the chisel shank. The chisel transmits a wave of compression only, the duration of which is determined by the length and shape of the piston. As the pulse propatates in steel with a velocity of approxi¬ mately 5000 m/s and practical considerations preclude varying the length of the piston by more than a few centimeters at the most, it is not85 feasible to modify the shape of the pulse in any significant degree by increasing the length of the piston. A spring arrangement in the form of a striking pad on top of the chisel shank or some other form of spring arrangement, which might conceivably be incorporated in the piston or the chisel, will increase the duration of the impulse. How-90 ever, a large part of the impact energy delivered by the piston is thereby lost, that is to say, only a limited amount of the said energy is transmitted to the point of the chisel. Considerable problems are also met in getting the elastic material to withstand the impacts of the piston. Since a scaling hammer, like other similar hand-held tools,95 must in order to be manageable be kept with fairly narrow limits of size and weight, it is difficult, if indeed possible at all, to modify the design of the tool in such a way as, on the one hand, to increase the impact energy delivered by the piston to compensate for the above- mentioned losses and, on the other hand, to provide sufficiently large100 striking faces for the elastic material to withstand the impacts.Therefore, the said attempts have not led to any practical result in the form of new, acoustically damped tools, and the problem has been regard¬ ed as more or less insoluble in practice.In the present invention the problem has been attacked from another105 angle, as will be described in further detail hereafter with reference to the appended drawings. Of the latter, Fig. 1 is a side view, partly cut away, of an application of the invention to a pneumatically powered chipping tool. Fig. 2 is a side view, likewise partly cut away, of an application of the invention to a sledge-hammer. Fig. 3 is a graphC'FlV-'.-, '•'- ?0 > ■ 110 showing two different pulse shapes and Fig. 4 is a graph of acoustic measurements.The embodiment of the invention exemplified in Fig. 1 shows on of a pneumatic chipping tool, such as a scaling hammer, denoted 1 in drawing. The tool is provided with a driving mechanism of the type115 described in detail in the applicants' Swedish Patent Applications N 7503970-1 and 7603252-3. The driving mechanism comprises an axially moveable impact piston 2, terminating at its rear end relative to th directin of striking in a broadened, plate-shaped end piece 3 which together with an 0-ring 4 seals a driving compartment formed between120 plate-shaped end piece and an element 5. Compressed air is fed into driving compartment via a pipeline 6. Inasmuch as the 0-ring 4 acts a valve which alternately seals and opens the driving compartment ra ally, the impact piston 2 will alternately be driven forward by the pressure and back by a spring 7.125 The number 8 is used as a general designation for the impact e ment of the invention. This consists, in the embodiment illustrated Fig. 1, of the impact piston 2 and of a chisel unit 9 the rod 10 of which is inserted into the impact piston and rigidly united thereto the nut 11. The chisel unit 9 consists, apart from the rod 10, of130 a housing 12 in which the chisel 13 is mounted. Inserted in the chis 13 is a chisel bit 14 of hard metal. The chisel 13 and the housing 1 have a limited axial freedom of movement with respect to each other provided by a stiff spring arrangement 15, illustrated in the figure a number of cup washers.135 The impact element 8 thus consists of two masses, a driving ma16 (consisting of the impact piston 2, the nut 11, the chisel rod 10 the housing 12 rigidly united with each other) and a striking mass 1 (consisting of the chisel 13 and the chisel bit 14 rigidly united wi each other), which masses have a limited freedom of axial movement wi140 respect to each other via the stiff spring arrangement 15.The spring arrangement 15 may naturally consist of some other of spring than the package of cup washers illustrated in the present example, e.g. rubber springing. However, a stiff steel spring, such a package of cup washers, offers advantages in that it causes little145 energy loss in the form of heat. The air which leaves the driving compartment each time the latter opens is discharged through the impact element 8 via ducts 18 a - e. The passage of the air through the chisel housing and the chisel is an effective means of removing any heat which may be generated by the150 action of the spring arrangement 15. This is a particular advantage if rubber or plastic springing is used.When the chisel bit 14 is brought to bear on a workpiece while the chipping hammer driving mechanism is operating, the workpiece will be subjected to a rapid succession of blows from the chisel bit as the155 latter reciprocates together with the whole of the impact element 8. Specifically, the cycle of operation will be such that, first, the entire impact element 8 accelerates forwards towards the workpiece. When the chisel meets the workpiece, the striking mass 17 is retarded first, while the driving mass 16 continues pushing forward, thereby160 compressing the spring arrangement 15. This storage of energy in the spring delays the return motion of the two masses for a brief moment.Unlike the case of conventional scaling hammers, in which a piston strikes the shank of a chisel, the pulse of force does not travel from the chisel shank down through the chisel, but originates at the impact165 of the chisel bit on the workpiece. The cycle consists of a wave of compression which travels up the chisel (the striking mass 17) and a tensile wave which passes back down to the chisel bit. The initiation of the tensile wave is delayed since the driving mass 16 continues exerting force via the spring 15 and maintains the compression of the170 striking mass. The delay of the tensile wave lengthens the duration of the impact, thus increasing the duration of the pulse of force. The spring 15 causes a certain energy loss, which is negligible compared to the kinetic energy of the driving mass transmitted to the chisel bit.The increasedduration of the pulse is achieved mainly at the price175 of a certain reduction in the maximum level of force. The alteration in the shape of the pulse from what it would be if the impact element 8 consisted of a single rigid mass is determined by the rigidity of the spring and the relative magnitude and position of the masses. Tests with both a sledge-hammer and a scaling hammer have shown that it is180 preferable to use a driving mass which is considerably greater than the striking mass and to locate the spring arrangement at a distance from the point of impact which is considerably shorter than the overall 6 length of the impact element. In a scaling hammer good results have been obtained with an impact element in accordance with this invention,185 conforming essentially with Fig. 1, in which the weight of the striking mass was only 15 - 20 % of the total weight of the impact device, and i which the spring arrangement was located at a distance from the point o the chisel equal to barely one third of the overall length of the impac element.190 When the striking mass 17 is caused to impact upon a workpiece, immediately begins to cut into the workpiece by virtue of its own kinet energy, which has been imparted to it in the course of the preceding acceleration of the entire impact element 8. This is immediately follow by the successive transmission of the energy of the driving mass by the195 agency of the spring 15. Thus the spring 15 need not be subjected at the moment of impact to that part of the kinetic energy which is borne the striking mass itself. It is a further advantage that the striking mass is already moving in the same direction as the spring 15 and the driving mass 16 and has already begun to penetrate the surface of the200 workpiece when the energy borne by the driving mass begins to be trans¬ mitted, since this circumstance naturally makes the transmission proces smoother. It also has a desirable effect on the technical performance that the transmission of the additional energy begins at a point when the curve of the pulse has already risen some distance and that the205 greater part of this additional energy is delivered during the phase in which the maximum force level is reached, so that this level is main¬ tained for a longer period of time, as shown by Curve 2 in Fig. 3. This gives a high energy efficiency.It will be readily understood that this work cycle implies a gre210 difference in both technical performance and the stresses acting on the spring, compared to a transmission sequence via impact piston - spring chisel shank - chisel bit in the manner known hitherto. The chisel in the latter case is held essentially still against the workpiece when th cycle begins and cannot begin cutting into the workpiece until a suffi-215 cient amount of energy has been stored and transmitted to enable the point of the chisel to overcome the resistance of the material of the workpiece. The force curve thus takes on a shape which is disadvan¬ tageous with respect to technical performance and, as mentioned above, both the stresses on the spring and the energy losses are high.~ E_ TI_.) 220 The shape of the pulse of force above-mentioned, as per Curve 2 in Fig. 3, was obtained by measurements on a scaling hammer equipped with an impact element in accordance with the invention.Fig. 4 shows comparative acoustic measurements carried out on a pneumatic scaling hammer working on a flat metal plate resting on225 a damped surface. Curve 1 was obtained when the scaling hammer was operating with an impact element without an anti-noise spring arrange¬ ment and Curve 2 when it was fitted with an impact element in accordance with the present invention. When measured with an A-filter the damping obtained as per Curve 2 represents a value of 13 dB(A).230 It is claimed above that it is possible to avoid the excitation of certain frequencies of vibration in the workpiece by modifying the pulse of force. In other words, it is claimed that the workpiece itself - by virtue of its dimensions etc., - has no critical effect in this respect. This has been substantiated by tests of .the same type as those reported235 in Fig. 4 carried out on a number of workpieces of varying dimensions and having the form of both large faces of metal plate and stiffened angle structures, both freely supported and resting on an acoustically damping surface. In every case the shape of the curves was essentially the same with regard to the damping at the various frequencies of vibra-240 tion. The damping obtained in dB(A) varied over the range from 9 to 13 dB(A) only, with an average damping of approximately 11 dB(A). Thus it seems clear that a suitably designed impact element in accordance with this invention makes it possible to damp certain defined frequencies without the characteristics of the workpiece having any decisive influ-245 ence thereon.A means of further increasing the duration of the pulse of force and improving the chipping action of the tool on the workpiece, in the case of an impact element according to the invention equipped with a chisel, is to increase the plastic penetration of the chisel into the250 workpiece by providing the chisel with a bit 14 of hard metal. This contributes importantly towards the aim of this invention, namely, for the purpose of damping undesirable sound frequencies, to be able to operate on the workpiece - with satisfactory performance - using a lower maximum level of force and a generally smoother force cycle than in255 conventionally equipped chipping tools. It has been found quite pos¬ sible to use such a hard metal bit, made of a fairly tough grade of rock drill steel, on an impact device in accordance with the invention wit out the metal cracking. On the other hand, such a bit can hardly be used on a scaling hammer or chipping hammer working on the impact260 piston - chisel shank principle, as the tensile stresses are so great that there is a risk of the bit cracking even with the tool idling. A further advantage obtained with a hard metal bit is that its high re¬ sistance to wear greatly increases the life of the chisel.Fig. 2 shows an example of the application of the invention to a265 hand-powered tool in the form of a sledge-hammer. The sledge-hammer is fitted with a shaft 19 on which the impact element 8 is mounted. T impact element is provided with a shaft mounting 20 and consists of a driving mass 16 and a striking mass 17. Two striking heads 21, 24 are mounted so as to be axially moveable in a casing 22 under back-pressu270 exerted by a spring arrangement 15. The spring arrangement is axially guided by a pin 23 on the striking head 21. When the striker swings t sledge-hammer so that the head 21 delivers the blow to a workpiece, t head 21 acts as the striking mass 17, while the function of the drivi mass 16 is performed by the shaft 19, the shaft mounting 20, the casi275 22 and the head 24, which is held by the spring 15 against its seat in the casing 22 and is propelled by the latter, so that the head 24 acts as a unit rigidly united with the casing. If, instead, the strik delivers the blow with the opposite face of the sledge-hammer the hea 24 will act as the striking mass 17 and the other components as the280 driving mass 16. By providing one of the heads with a pin 23 and the other with a matching drilled-out hole, as illustrated in Fig. 2, we obtain different relatinships between the weights of the driving and the striking mass, depending on which way round the sledge-hammer is used. One can take advantage of this to obtain damping of different285 sound frequencies in different types of work. Tests carried out on a large metal plate with a prototype sledge-hammer conforming essen¬ tially to Fig. 2 shpwed that the spring arrangement 15 caused a negligible loss in energy transmission from the sledge-hammer to the plate. It was also found that the sledge-hammer produced a sound290 spectrum dominated by higher frequencies than in the case of a con¬ ventional sledge-hammer. The ringing low-frequency sound which usually causes the worst noise nuisance when hammering large plates in big engineering works and at shipyards was thus not excited in the plate. .The spring arrangement causes the sledge-hammer to make a 295 smooth, high rebound after each blow. In at least some types of work this is an advantage in that the rebound has a labour-saving effect. Further, thanks to the smooth cycle given by the spring arrangement, no shock wave passes into the hands and arms of the striker. If it should be desired to damp the rebound it is possible to do so in a 300 known manner by filling some part of the sledge-hammer or the lower part of the shaft with lead shot.The embodiments illustrated are only examples of applications of the invention, and it should be immediately apparent that the in¬ vention can also be applied to other types of striking tools and 305 devices than those shown. | Claims1. An impact element having the effect of elongating the pulse of force in impact tools and devices for chipping, hammering and simila operations, c h a r a c t e r i z e d i n t h a t the strikin motion is generated by an element (8) which is axially moveable as a whole and consists of a driving mass (16) intended to be actuated by propelling force, and a striking mass (17) located in front thereof relative to the direction of striking, which masses possess a limited freedom of axial movement with respect to each other in that they are coupled together by a stiff spring arrangement, e.g. cup washers (15) extremely hard plastics or gas cushions.2. An impact element in accordance with Claim 1, c h a r a c t e i z e d i n t h a t the driving mass (16) is of considerably greater weight than the striking mass (17), being preferably at least twice its weight. 3. An impact element in accordance with either of the preceding Claims, c h a r a c t e r i z e d i n t h a t the spring arrangement (15) is located at a distance from the forward end (rela¬ tive to the direction of striking) of the striking mass (17) which is less than half as great as the overall length of the impact element ( and preferably about one-third thereof.4. An impact element in accordance with any of the preceding Claims, designed to be powered by compressed air or similar pressure medium, c h a r a c t e r i z e d b y ducts (18a - e) provided in the impact element for the discharge of the pressure medium, the ducts being so arranged that the pressure medium cools the spring arrangement (15) in the course of its passage.5. An impact element in accordance with any of the preceding Claim c h a r a c t e r i z e d i n t h a t the said element is fitt with a chisel (13) with a bit (14) of hard metal. | EDSTROEM KJELL; NILSSON GORAN ALFRED; WIKLUND H; EDSTROEM K; NILSSON G | EDSTROEM K; NILSSON G; WIKLUND H |
WO-1979000503-A1 | 1,979,000,503 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | F16H55 | null | F16H55 | F16H 55/08H, F16H 55/14 | PRELOADED CONFORMAL GEARING | A form of gearing (11, 14) that is radially preloaded and utilizes closely conforming teeth (31). The preloading ensures that the higher torque capacity of conformal teeth (31) can be realized more fully than in fixed center gearing, and the conformal tooth profiles, if concave-convex, ensure that the amount of preload needed is minimized since the effective pressure angle for such teeth, diminishes as the transmitted torque increases. | PRELOADED CONFORMAL GEARING The gearing herein disclosed is essentially an improvement over gearing disclosed in prior art United States Patents Nos. ~ _ -&9 A~& and 3,301-,795. These earlier patents proposed gearing in which the teeth were conformal, hut the radial preload was to he applied hy the local resilience of the material of the teeth themselves and the rim region immediately beneath the teeth. In practice this construction was found to afford a very restricted torque capacity because the application of the preload by the resilience of the tooth and rim material close to the pitch point required the use of pliable materials for teeth and rim having a very low modulus of elasticity. When a large torque was applied to the gears, tangential shear deformation of the teeth and rims caused the pitch of the teeth coming into mesh to be reduced on the driving gear and increased on the driven gear. As a result, the incoming teeth had a tendency to climb up the flanks of the driven teeth, especially if the pressure angle was higher than the friction angle as was often the case with the preferred tooth material, which was identified as elastomeric. If this tooth climbing continued for more than a few pitch lengths, it would progress to the point at which the teeth would actually climb over each other or ratchet. The second of the two patents cited, U.S. No. 3,30^,795, sought to correct this problem by increasing the tangential rigidity of the rim material. This alleviated the problem to some extent, but because this patent retained the idea of applying the preload by means of the resilience of the rim material immediately adjacent to the pitch point, the material of the teeth and the surface of the rim between adjacent teeth had to remain quite pliable in order to transmit the radial preloading force through the teeth. The tooth climbing problem was therefore not entirely corrected. The present invention undertakes to provide a construction that completely eliminates the climbing problem by utilizing a much-more rigid tooth and rim construction. When this is done, the preloading force can no longer be developed locally, in the vicinity of the pitch point, but must be generated at a point more or less remote ( spatially displaced ) from the pitch point and transmitted to the tooth meshing region through the rim of at least one of the mating gears.How remote the means that apply the preloading force will be from the pitch point depends on which of several construction types is employed. The most remote means that is suitable for applying a preload to a pair of gears is probably a shaft for one of the gears that has more than usual limberness. This is an economical construction but introduces a con¬ siderable degree of lateral movability to one of the gears that tends to promote dynamic instability and effective backlash (or wind-up ).A more effective but somewhat uneconomical way to provide preloading by means remote from the mesh region is to mount one of the gears on a pivoted arm that is spring-loaded towards the other gear. This is the most common prior art device used for radially preloading gears. Its disad¬ vantage is that it requires a flexible coupling to transmit torque to or from the floating shaft of the pivotally mounted gear.A more economical way to provide preloading for gears is to build a suitable elastic means into the body of at least one of the gears, then to mount the gears with a reduced center distance or interference fit. The gear rim is mounted to be movable as a whole if it is relatively rigid, or movable in a localized manner if it is more flexible and is mounted for egging under load. In either case the elastic element incorporated in the gear body must be relatively remote from the tooth contact zone if the teeth and rim are to be rigid enough to prevent tooth climbing. Several alter¬ native constructions utilizing elastic elements in the gear body to impose a preload are disclosed in the drawings.The use of radial preloading is a well-known method of eliminating backlash in gearing. Gear teeth having closely conforming profiles are also well-known (e.g., U.S. Patent Nos. 1,601,750; 3,937,098; 3,982,V+5). Both radially preloaded gears and conformal teeth have inherent disadvan¬ tages, however, if used separately: Radial preloading of conventional involute gearing produces excessively high bearing loads and short tooth wear life; conformal gear teeth suffer from reduced torque capacity as a result of acute sensitivity to center-distance error. The proposed con¬ structions eliminate the disadvantages of both radially preloaded gearing and conformal teeth because the disadvantages of each are eliminated by use in conjunction with the other: Radial preloading eliminates the sensi¬ tivity of conformal teeth to center-distance error; and convex-concave conformal teeth have a pressure angle that diminishes as the torque load increases, so that a much smaller preload can be used without danger of the teeth riding up over each other when a torque overload occurs. (For involute gearing, shaft deflection causes the pressure angle to increase with torque load, rather than decrease.)The combining of conformal teeth with radial preloading not only eliminates the disadvantages that characterize each when used by itself, but preserves the important advantages of each. For example, the advantages of conformal gearing relative to involute gearing are as follows: (l) it has typically about twice the torque capacity; (2) it has about twice the tooth deformation under load and is therefore less sensitive to misalign¬ ment, pitch and lead-angle errors; (3) its torque capacity is not reduced if the teeth are made finer, so it has considerable potential as a low-noise gear form; and { k ) it has tooth contact areas that maintain a much thicker oil film and therefore operates more efficiently and wears longer.The special advantages of radially preloaded gearing relative to gearing that is not preloaded, and which are retained by utilizing this type of gearing in conjunction with conformal teeth, are as ollows: (l) it is not sensitive to center-distance errors, since the elastic deflection of the gear that is constructed or mounted to impose the preload is always designed to be much larger than the center-distance errors; (2) its insen- sitivity to center-distance errors allows the use of teeth that are much finer and therefore much quieter than conventional teeth; (3) preloaded gearing is well-adapted to being made self-aligning, since the structure that preloads the teeth can readily be arranged to apply its load at the mid-plane of the gear face; and ( h ) preloaded gearing lends itself readily to antibacklash constructions.Accordingly, the object of the invention is to provide a construc¬ tion for gearing that affords increased torque and wear capacity as well as reduced noise, and which is also well-suited for antibacklash applica¬ tions. The means to achieve these and other objects and advantages of the invention will be evident from the drawings as explained in the specification -k-that follows:Fig. 1 is a gear set embodying the invention, in which a double helical pinion, shown in side view, is mated with a gearwheel shown in diametral section.Fig. 2 is a schematic axial view of the rim of the gearwheel 1 shown to a greatly reduced scale and illustrating the egging that is induced by a radial load F. Fig. 3 is a much enlarged section of the pitch point area of Fig. 1, -showing the engaged teeth.Fig. h is a view similar to Fig. 3 showing an alternative tooth form.Fig. 5 is a partial axial view of a gearwheel such as the one illustrated in Fig. 1, showing an alternative construction for the web.Fig. 6 is also a partial axial view of a gearwheel showing another alternative construction for the web.Figs, 75 8 and 9 are partial diametral sections of gearwheel rims and webs, showing other alternative constructions.Fig. 10 is a view similar to Figs. ~_ 8 and 9 but for an internal or annular spur gearwheel.Fig. 11 illustrates the application of the invention to a set of bevel gears, the larger of which, shown in diametral section, preloads its mate by means of the flexure of a membrane-like web.In detail and referring to Fig. 1, a pinion 11 is mounted on a torque-transmitting central shaft 12 and has double-helical teeth 13 formed on its external surface or rim. This pinion 11 engages a gearwheel ik (shown in diametral section) which has a flexible toothed rim 15, immediately inside which is a radially deformable web structure l6. This web structure 15 is deformable under radial load because it has concentric grooves 17 in staggered relation to similar grooves on the opposite side of the web structure l6. If the gearwheel ik is large, there will also be a solid or relatively rigid web portion 18 between the deformable web structure l6 and the central shaft 19- Web portion 18 is fixed to a collar on shaft 19 by means of conicalheaded screws 20 that shift the gear web portion 18 radially, to apply the preload as they are tightened.The purpose of the deeply grooved web structure iβ of the gear¬ wheel lJ+ is to provide a connection between the gearwheel rim 15 and the rigid web portion 18 that can sustain considerable radial deformation but will be quite resistant to tangential shear deformation. The construction shown takes advantage of the fact that a thin-walled sleeve of any appreci¬ able length can readily be egged at one end while the other end is con¬ strained to remain cylindrical, or constrained to be egged to a lesser extent. If two or more concentric cylindrical sleeve portions, one inside the other, are interconnected at their ends, as in the case of the web structure l6 shown, considerable radial movement of the rim 15 can be accommodated without overstressing the web materials even in a gearwheel Ik of relatively small diameter, particularly if the axial length of the sleeves is of the same order of magnitude as their radii. This may lead to the axial length of the sleeves being at least as great as the face width of the rim 15- as shown.The concentric sleeve construction of the web structure l6 of Fig. 1 ifl. effect produces radial deformability by utilizing staggered circum- ferentially extending grooves 17 that make the web structure l6, when viewed in the diametral section of Fig. 1, afford a very sinuous or indirect path between the rigid web portion 18 and the rim 15• There are a variety of shapes this sinuous path may be given, but to attain the necessary radial deformability, the length of an imaginary line lying midway between opposed surfaces of the web structure 16 must be at least 30 longer, and preferably 50$ longer, than the thickness of the web structure l6 measured in a direc¬ tion normal to the pitch surface of the gearwheel 1^. In the configuration illustrated, the sinuous path followed by the web structure l6 in the diametral plane is more than four times as long as the overall radial thickness of the web structure l6.In the construction of Fig. 1, it is the elasticity of the body itself of gearwheel l that is utilized to apply the preload. This effect is achieved by mounting the gearwheel ik and pinion 12 on a center-distance that produces an interference fit. (For the purposes of this specification and the ensuing claims, an interference fit means a positioning of the axes of rotation of a pair of gears that requires at least one of them to deform or deflect in a direction normal to the pitch surfaces in the tooth contact zone, in order for the gear set to be assembled. In the case of Fig. 1, this would mean that the distance between the centerlines of pinion 12 and gearwheel Ik must be smaller than the sum of the unstressed or unpreloaded pitch radii of the pinion 12 and gearwheel ik . )The amount of radial deformation needed in order to control theBURHAT/-_OMPIV A^ W1PO * preload within say 10$ is not very great. For typical manufacturing toler¬ ances plus bearing wear and thermal effects it is usually adequate to provide for radial deformations of 1 to 3% of the gear radius. A web structure lβ such as shown in Fig. 1 will readily allow this much radial deformation if the wall thickness of the concentric cylindrical sleeve segments is not too great. As is always the case in engineering structures, it is bending, as opposed to direct stress, that produces major deflections. In the con¬ struction of Fig. 1 the tangential deflection produced is almost negligible since none of the elements is subjected to bending in the tangential direc¬ tion. As a result, the torsional deformation of the web structure l6 is typically only 1 to 2% of its radial deformation, and the elastic backlash or wind-up of the body when torque is applied is therefore almost negligible.As a result of the stiffness of the web structure l6 with re-spect to torsional loading, the attainment of a 1 to 3% radial deformation requires that the rim 15 be flexible enough to deform by this amount with¬ out exceeding the yield point of the rim material. This produces a pattern of loads and deflections shown in Fig. 2, which is a reduced-scale schematic view of a typical flexible rim 15 such as that employed in Fig. 1. If an external radial load F is applied at point A, the flexible rim 15 takes the approximate form of an ellipse with minor axis AB and major axis CD. This egging compresses the web structure (l6 in Fig. 1, not shown in Fig. 2) at point A, and to a slightly lesser extent at point B on the rim 15 opposite to A, and at the same time extends or thickens the web structure at points C and D, 90 removed from A and B, by at least half as much. Because the web structure 16 is so much suffer with respect to shear forces than to radial forces, the main support of the load F is not provided by the web elements between point A and the gearwheel center at 0, but is instead provided by shear forces s,s at points C and D. In effect, the semi-elliptical arc DAC is therefore an elastic arch that supports the load F. In other words, it is the resilient rim 15, supported mainly at points C and D, that comprises the principal means that preloads the teeth against each other at point A. (The radial forces exerted by the web structure l6 on the rim 15 are so much smaller than the shear forces s,s that they have been omitted from the diagram of Fig. 2 in the interest of clarity. Torque forces are also omitted, in the interest of clarity; they would consist of a tangential force at A and a pair of forces immediately inside the rim 15 at points A and B, directed opposite to the external tangential force at A, plus additional shear forces uniformly distributed around the inside of the rim 15.)An additional advantage that may be obtained from the use of a gear body that includes an elastic element in the web is that the toothed rim 15 may be made self-aligning. In the case of the construction of Fig. 1, any tendency of the rim to tilt may be eliminated if the combined diametral section of the rim 15 and web l6 has a principal moment of inertia that coincides with the mid-plane of the rim 15. An alternative, if a rim and web configuration is used for which the principal axes of inertia are not radial and axial with respect to the pitch surface, is to design to ensure that the shear center for the combined diametral section of the rim and web lies in the mid-plane of the rim 15. (The term shear center is defined in Strength of Materials, by S. Timoshenko; Van TTostrand, 3rd ed. , Part 1, art. 52.)It should be noted in connection with Fig. 1 that the rim 15 and web structure lβ may have many different forms that meet these requirements with respect to principal axes of inertia or shear center. In all of them-, however, it will be found that the radially extending portions that connect the sleeves to rim 15 or web 18 and to adjacent sleeves have a stiffening effect on the structure as a whole. This stiffening may be reduced by cutting small holes in the axial direction through these radially extending por¬ tions , pre erably every 5 to 10 of circumference.As indicated above, the principal advantages of preloaded gearing and conformal teeth can only be realized by utilizing them together in the same gear set. And just as there are preloading methods of varying degrees of desirability, there are different types of conformal teeth that afford different advantages. The most generally useful tooth form is illustrated in Fig. 3, which is a transverse section shown by the arrows 3,3 in Fig. 1, greatly enlarged.In this figure the conformal teeth 31 have circular arc tooth profiles with radii 32 for which the centers are on the pitch circles 33, 3*+ of the pinion and gear respectively. As a result of the preload, the pitch circles 33, 3*+ are coalesced throughout a distance 35, 3 that covers at least two circular pitch lengths. In the mesh region between points 35 and 3 there is no relative rotation of the teeth 31 and therefore no relative sliding. During tooth engagement and disengagement near points 35 and 3 there is a slight relative rotation of the teeth, and for this reason it is 'desirable to form the opposite flanks of the teeth 31 with centers 37, 38 for the addenda and dedenda respectively, that coalesce to a common point because the pitch circles on which they lie are coalesced. This ensures that there can be no binding of the teeth, since the meshed profiles mate like the surfaces of cylindrical sleeve bearings.It will be noted that the tips 30 of the teeth are flat, so that the tooth addendum profile is not a full semi-circle, as in U.S. Patent No. 3,709,055, but is instead a pair of discrete circular arcs having the same center. In effect, the tooth height is less than half the tooth thickness at the pitch surface. This flat tip has two purposes: It provid a region in which debris from tooth wear can accumulate, it allows for finish machining of the ends of roll-formed teeth, and it removes the tooth portion that would prevent the preload from bearing fully on both adjacent tooth flanks, which is a feature that is essential in antibacklash gear sets.In conformal gearing, mating teeth may be in contact over most or all of the tooth height. If the tooth profile has considerable changes of curvature, as in the case of the teeth of Fig. 3 that have working profiles including both convex and concave circular arcs, the term pressur angle as used in relation to conventional gear forms has a rather indefinite meaning. It is therefore preferable to use the term transverse profile tangent angle with respect to a particular point on the tooth profile, meaning the angle in the transverse plane between a line tangent to the profile curve and a line normal to the pitch surface through the point in question. Alternatively, the term effective pressure angle ■ may be used to describe the angle between the resultant tooth pressure component in the transverse plane and a line tangent to the coalesced pitch surfaces at the point where they intersect the tooth profile.In the case of the tooth profiles shown in Fig. 3, the effective pressure angle varies greatly depending on the tangential force (or useful tooth load component ) and the relation it bears to the preload. When there is no torque applied, the main tooth load is near the end of the addendum, where the transverse profile tangent angle should be at least 30 and preferably 50 to 6θ . As torque is applied, more and more of the tooth pressure is carried by the tooth profile portion near the pitch surfac where the transverse profile tangent angle approaches zero. This means that the radial forces developed between mating teeth and tending to separate the gears do not increase linearly with applied torque, but may instead be almost, independent of applied torque. This is a veiy desirable feature, as it means the preload can be much smaller than it would otherwise need to be to make the teeth safe against ratcheting during momentary over¬ loads. The general shape the profiles must have to ensure that the separating force decreases rather than increases as torque load is applied, is that the transverse profile tangent angle for profile points of the teeth of both gears increases with distance from the respective pitch surfaces of the gears.As there are important advantages in making the teeth of preloaded gears as fine as ^possible, so as to minimize noise, wear and cost of manu¬ facture (usually by roll-forming), the preferred tooth modules will be from about 0.2 to 0.02. In the case of plastic gears, however, the tooth size may be somewhat larger. In most applications, the teeth can be made fine enough so spur (or straight bevel) teeth will operate very smoothly, and the double-helical teeth shown in Fig. 1 are not required.It should be noted in connection with the tooth profiles shown in Fig. 3 that in order to prevent overloading of the tips of the teeth and reduce engagement shock, it is desirable to make the radii of the convex circular arcs, when the teeth are unloaded, slightly shorter than those of the concave radii, by an amount that is usually less than 10$. When the teeth are fully loaded, the arc center for the convex arc 39 moves to a point 37' farther from the tooth profile as a result of the tendency of the tooth pressure to reduce the curvature of the tooth surface slightly. Similarly, the arc center for the concave arc ^0 moves to a point 38' closer to the tooth profile as a result of the tendency of the tooth pressure to increase the curvature of the concave tooth. The points 37' and 38' are on the pitch circles 33 and 3*+ respectively, and when the pitch circles coalesce in the zone 35-36, the points 37' and 38' coalesce at the common arc center points indicated as 37, 38.Fig. k shows an alternative tooth form to that of Fig. 3. In this case, the teeth 4l on the pinion have working profiles that are convex circular arcs. In this all-addendum form, the bottom lands of the convex teeth lj-1 and the top lands of the concave teeth k2 lie in the respective pitch surfaces 3, hk of the pinion and gear on which they are formed. These pitch surface lands thus comprise cylindrical surfaces on which the mating gears can roll on each other without sliding, so there is no tooth wear induced by the preload. This means that opposed, high pressure-angle tooth flanks are not needed for carrying the preload, and if desired, back¬ lash may be provided between mating teeth. On the nonloaded side of the teeth, the arc centers 4-5 of the convex teeth will be slightly closer to the profile than the arc centers h6 of the concave teeth, but when torque load is carried, these arc centers ^5, k6 will coalesce at a common point ^7, for reasons indicated above. If the teeth are extremely fine, they may be spur, but otherwise should be helical or, preferably, double helical, for smoother rolling on the cylindrical land surfaces.In Fig. k the convex teeth kl are shown as being narrower than twice the profile radii. If the space between adjacent concave teeth 2. is widened, the convex teeth l may also be made wider so that the point where a line connecting arc centers ^5 and h6 crosses the coalesced pitch circles would coincide with the arc center ^ . This would give the teeth the same common profile circle flank character as shown in Fig. 3, so there would be no possibility of the teeth binding in applications where there is little or no backlash.As noted above, to make a body fashioned-from-a-rigid-material deformable, it is necessary to shape it so that some portion of it is subjected to bending, as distinguished from direct stress. As it is radial deformability that is desired in this case, the beam structure that is to be subjected to bending must extend either axially or circumferentially. In the case of the construction of Fig. 1, the beam elements in effect are the elements that make up the cylindrical sleeves, and therefore extend axially. In Fig. 5 an alternative construction is shown, in which the beam elements 51 extend circumferentially. These beam elements 51 are created by forming a series of circumferentially extending slots arranged in two or more concentric rings immediately inside the flexible toothed rim 15. These slots 52 go completely through the web 53 and are separated by solid sections 5-+ that are opposite the centers of adjacent slots 52 and transmit the torque from the web 53 to the rim 15. Radial compression causes the slots 52 to be deformed into a slightly hour-glass shape, allowing the rim 15 to assume an approximately elliptical form as in Fig. 2 as points A and B move closer to 0.If two different materials are used, one of which is very rigid relative to the other, it is possible to design webs that have the sameA ~~~_'Ar, WiPO characteristics as those illustrated in Figs. 1 and 5, but which do not employ concentric corrugations or circumferentially extending slots. One such design is shown in Fig. 6, in which radially extending fins 6l are attached to the toothed rim 15 at uniform angular intervals in planes con¬ taining the central axis of the gear. Between each pair of adjacent fins 6l is a similar fin 62 attached to the web 63 separated from the fins on the rim 15 by a pad of rubber 6k or other elastomer. Because elastomers have a large Poisson's ratio, the shear modulus is very small, so these radially oriented pads are readily deformable in the radial direction but deform very little in response to loads in the direction tangential to the rim 15.In the configuration of Fig. 7, the toothed rim 1 has a T-shaped section, so it has limited flexibility. It is connected to a solid web portion J2 by means of a circumferentially extending ring of rubber 73 or other elastomer. This is not a desirable construction for an antiback¬ lash gear set, because the rubber ring 73 deforms as much circumferentially under torque load as it does radially under the preload, but it may be suitable for some application where backlash or wind-up is not undesirable.Fig. 8 shows a modification of the resilient web construction l6 of Fig.. 1. In this case the web l6 is made up of a radially deformable ring 8l which in section has a zigzag shape comprising a series of semi- ellipses instead of concentric sleeves, which connects the flexible toothed rim 15 to the solid web 82. This kind of ring is readily fabricated by stamping or spinning of flat sheet metal rings.Fig. 9 shows another variant on the construction of the gearwheel ik of Fig. 1, in which a plastic flexible rim 15 is connected to a solid plastic web 91 by a pair of sheet-metal concentric sleeve elements 92, 93 that are arranged symmetrically with respect to the center-line of the rim 15 section. This construction insures that the rim 15 will have no tendency to tilt (i.e., will be self-aligning) under the action of the preload and applied load, and that the resilient web structures 92, 93 will be less subject to cold flow and hysteresis than if the gear were made entirely of plastic.Fig. 10 shows a construction for an internal or annular spur gearwheel. In this case the teeth 101 are formed on the inner surface of the flexible rim 15. Immediately outside rim 15 is a cylindrical sleeve 102 connecting the rim 15 to the solid web 103, but if desired a series of concentric sleeves may be employed, as in the resilient web l6 of Fig. 1. The number of concentric sleeves 102 required is entirely a function of how much radial deformability is needed to ensure the actual preload is reasonably close to the intended preload. The web 103 connects to the central shaft on which the gearwheel is mounted.Fig. 11 shows a straight bevel pinion 111 mated with a second conic gear 112, which is shown in diametral section. In this case the preload is applied by flexure of a membrane-like web 113. For the conformal teeth to fit properly, they must be formed as though for a gear set that has an angle between center lines that is slightly larger than 90 . This is becaus the common pitch cone apex point 11^ is slightly displaced from the inter¬ section point 115 of the shaft center lines. It will be evident that as an alternative to the flexible membrane construction of Fig. 11, bevel gears may be constructed in the manner of Fig. 1 simply by making the cylindrical rim 15 and cylindrical sleeve elements frusto-conical instead of cylindrical.A number of observations may be made regarding the embodiments of the invention illustrated: (l) The grooves and slots shown in Figs. 1, 5, 9 and 10 are shown undeformed, in the interest of clarity; after assembl of the gear set with an interference fit, as hereinbefore defined, these grooves would be partly or, in designs intended to be immune from the danger of tooth ratcheting or overstressing of the beam elements during overload, completely closed up as a result of elastic deformation; (2) for plastic gears, tooth profiles such as those shown in U.S. Patents Nos. 3,82^,873 (Re. 28,115), 3,937,098 and 3,982,1+1*5 are suitable, as well as the profile types shown in Figs. 3 and k ; (3) an alternative to the tapered screws 20 shown in Fig. 1 are separate C-clamps or built-in jackscrews or wedges that egg the rim 15 as shown in Fig. 2, if the gear set must be assembled on non-separable shafts; ( k ) a layer of elastomeric or other high damping material may be cemented to the side of the rim 15 that does not have teeth, to reduce noise emission; (5) if the pinion and gear are both small, it may be desirable to make the pinion resilient instead of, or as well as, the gearwheel; (6) helical teeth that are circular arcs in the normal plane instead of the transverse plane are also envisioned, but will not have the capability to accept relative rotation under preload without binding, unless they are made of plastic; (7) the gear of Fig. 1 could be enlarged to become a rack resiliently supported or if movable could be held against the pinion by one or more rollers; (8) if the teeth of a set of gears are fine enough, they may he c nfoπn -l , un dpfined belπw, even thuυr.h the mating uurf/ieea> are both convex; (9) for good antibacklash characteristics, the resilient web structure 16 of Fig. 1 should have an effective radial load modulus, as hereinbelow defined, that is substantially less than twice its effective tangential shear modulus, as hereinbefore defined; (lO) the tooth core materials that show the least tendency to cause tooth climbing, as described above, are materials that are non-pliable, as hereinbelow defined; (ll) hydraulic, pneumatic, or electromagnetic means may also be employed to preload one gear against its mate.For the purposes of the present specification and the ensuing claims, the following terms shall have the following meanings: flexible as applied to the rim structure of a gear means having a ratio of radial thickness to radius that permits said rim structure to sustain a radial deformation of at least 1/2$ without inducing in any part of said rim structure a stress in excess of the yield stress; effective radial load modulus means the ratio of (a) the radial load per unit circumferential length of the web structure to (b) the radial deformation produced by that load; effective tangential shear modulus means the ratio of (a) the tan¬ gential shear load per unit circumferential length of the web structure to (b) the shear deformation produced by that tangential shear load; pinion means the smaller of a pair of mating gears, except in a unity-ratio gear set where either of the pair may be considered the pinion; gearwheel means the larger of a pair of mating, gears except in a unity-ratio gear set where either of the pair may be considered the gearhweel in the case of a rack-and-pinion set, the gearwheel has an infinite radius and is synonymous with the rack; a non-pliable material is one having a modulus2 of elasticity greater than 350 kp/mm , and a pliabl^'material is one having a modulus of elasticity smaller than this value, as for example an elastomer; radially preloaded, as applied to gear teeth, means the teeth on one pair of mating gears are urged radially toward the teeth on the other of said pair by forces that act regardless of whether or not the gears are subjected to torque loading; diametral section means a section through a gear or its web taken in a plane that contains the central axis of the gear; conformal, as applied to gear tooth profiles, means the teeth have a relative radius of curvature in the normal plane that cuases a transverse section of the tooth contact area to occupy at least two-thirds of the height of the tooth working profile when the gears are subjected to an applied torque that causes the material at the most critical point of which¬ ever gear is weaker to reach a condition of incipient yielding. | I CLAIM :1. A pair of mating gears comprising a pinion and gearwheel each having a toothed rim, said rim of said pinion being connected to a torque transmitting means, said rim of one of said pair having a portion in the tooth contact zone of said pair that is adapted to sustain components of movement in a direction normal to the pitch surface of said one of said pair in said zone, means spaced apart from said zone and radially preloading the teeth on said portion of said rim against the teeth on the rim of the other of said pair, said teeth having conformal profiles.2. A pair of mating gears according to claim 1 wherein said means comprises a body for one of said pair formed to deflect radially in response to radial load, and the axes of rotation of said pair are positioned to produce an interference fit between said pair.3- A pair of mating gears according to claim 1 wherein said rim of said one of said pair is flexible. k. A pair of mating gears according to claim 3 wherein said flexible rim is supported on a web having an effective radial load modulus that is less than twice its effective tangential shear modulus.5. A pair of mating gears according to claim k wherein a line in a diametral section and positioned midway between opposed surfaces of said web structure and extending from the innermost to the outermost part of said web structure has a length at least 30$ greater than the thickness of said web structure measured in a direction normal to the pitch surface of said teeth on said flexible rim.6. A pair of mating gears according to claim 5 wherein said length is at least 50$ greater than said thickness.7. A pair of mating gears according to claim k wherein said web structure is immediately inside said flexible rim.8. A pair of mating gears according to claim k wherein said web structure is immediately outside said flexible rim.9. A pair of mating gears according to claim 1 wherein the pitch surfaces of said toothed rims are frusto-conical.10. A pair of mating gears, according to claim 1 wherein said rim of said one of said pair i-; made of a non-pliable material.11. A pair of mating gears according to claim 1 wherein said means comprises a pliable element in said web structure.12. A pair of mating gears according to claim k wherein said web structure is symmetrical with respect to the mid-plane of said flexible rim.13. A pair of mating gears according to claim k wherein one of the principal moments of inertia of said flexible rim and said web structure combined coincides with the mid-plane of said flexible rim. lk . A pair of mating gears according to claim k wherein the shear center of said flexible rim and said web structure combined, lies in the mid-plane of said flexible rim.15. A pair of mating gears according to claim k wherein said web structure includes a cylindrical sleeve portion.16. A pair of mating gears according to claim k wherein said web structure includes a plurality of interconnected cylindrical sleeve portions .17. A pair of mating gears according to claim k wherein said web structure has a plurality of circumferentially extending slots arranged in a plurality of concentric rings, said slots and the solid sections between circumferentially adjacent slots in each of said rings being in staggered relation to the slots and solid sections of adjacent rings.18. A pair of mating gears according to claim 3 wherein the mag¬ nitude of the modulus of rigidity of said flexible rim causes it to deform radially, at points 90 displaced from the pitch point, at least half as far as it does in said tooth contact zone.19. A pair of mating gears according to claim 1 wherein the working profiles of said teeth are circular arcs.20. A pair of mating gears according to claim 1 wherein said teeth have lands that lie in their respective pitch surfaces.21. A pair of mating gears according to claim 1 wherein said gear teeth have transverse profile tangent angles of at least 30 at a point in the working surface of said profiles.22. A pair of mating gears according to claim 1 wherein each of said teeth has an active profile that includes both convex and concave portions.23. A pair of mating gears according to claim 1 wherein the core of said teeth is comprised of a material having a modulus of elasticity2 greater than 350 kp/mm .2k . A pair of mating gears according to claim 1 wherein the working surfaces of opposite sides of the teeth on one of said pair include profile portions comprisin-*- two circular arcs havinp a common center, -lb-25. A pair of mating gears according to claim 1 wherein the surfaces of the space between adjacent teeth on one of said pair include profile portions comprising two circular arcs having a common center.26. A pair of mating gears according to claim 19 wherein the radius of said circular arc profiles on the teeth of one of said pair is not more than 10$ larger than the radius of said circular arc profiles on the other of said pair.27. A pair of mating gears according to claim 1 wherein the addendum height of the teeth of one of said pair is less than half the tooth thickness at the pitch surface of said one of said pair.28. A pair of mating gears according to claim 2k wherein said profil portions have a common center only when said teeth are deformed by said radial preloading.29. A pair of mating gears according to claim 1 wherein said teeth are double helical.30. A pair of mating gears according to claim 1 wherein the trans¬ verse profile tangent angle for profile points of the teeth of both of said gears increases with the distance of said points from the respective pitch surfaces of each of said gears.31. A pair of mating gears according to claim 19 wherein the centers of said circular arcs lie adjacent the respective pitch surfaces of said gears.32. A pair of mating gears according to claim 1 wherein threaded means are provided to force one of said gears against the other of said gears to produce said radial preloading.33. A pair of mating gears according to claim 1 wherein the module of said teeth is smaller than 0.2.O PA - IP | ROUVEROL W | ROUVEROL W |
WO-1979000505-A1 | 1,979,000,505 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | F16C11 | F16B5, B65D7 | F16B5, F16C11 | B65D 7/34, F16C 11/04 | HINGE | A hinge for connecting an edge of a sheet member to a preferably planar surface, said hinge being intended to be used e.g. in foldable boxes and the like. This is made possible according to the invention in that a hinge member (5) having an annular portion (6) and a straight portion (7) extending substantially radially from the annular portion is arranged with a portion of the sheet member (1) between the edge and an opening (8) close to the edge extending through the annular portion (6) and with the straight portion (7) rotatably but axially non-slidably mounted in an opening in the planar surface (3). | HingeThe present invention relates to a hinge for con¬ necting an edge of a sheet member to a preferably planar surface, said hinge having many uses, e.g. for foldable boxes and similar objects. • In order to connect an edge of a sheet member to a planar surface hinges of different kinds are generally used. Howeverj these hinges only permit pivotal movement of the sheet member around a single, stationar pivot axis, said pivot axis also often being positioned at a distance from the planar surface. However, in many cases it is de¬ sirable that the sheet member can be pivoted around a pivot axis parallel to the planar surface and that said pivot axis can be turned in a plane that is parallel to the planar surface. This is, however, not possible with previously known devices, at least not unless very com¬ plicated and expensive designs are used.The object of the present invention is to provide a hinge of the kind mentioned above, said hinge meeting the requirements given above and further being of very simple design and cheap to manufacture. According to the invention this is accomplished in that a hinge member hav¬ ing an annular portion and a straight portion extending substantially radially from the annular portion is arrang¬ ed with a portion of the sheet member between the edge and an opening close to the edge extending through the annular portion and with the straight portion rotatably but axially non-slidably mounted in an opening in the planar surface.The invention is described more closely below with reference to the accompanying drawing, in which Fig. 1 is a perspective view of a hinge according to one em¬ bodiment of the present invention, and Fig. 2 shows a section along the line II-II in Fig. 1.In the drawing there is shown a sheet member 1, in the shown embodiment a flat sheet metal member, one edge 2 of which is intended to be connected to a planar surface 3 on a second sheet member 4, in the shown em- bodiment also a flat sheet metal member. The connection between the two sheet members is made by means of a hinge member , which as is most clearly shown in Fig. 2 in¬ cludes an annular portion 6 and a straight portion 7- In the embodiment shown in the drawing the hinge member consists of a metal wire or the like, whereby the annular portion 6 is made of the middle portion of the wire and the straight portion 7 is made of the end portions of the wire, which are folded as parallel legs substantially radial in relation to the annular portion 6. The annular portion 6 surrounds, as will be clear from the drawing, a portion of the sheet member 1 between the edge 2 of thi and an opening 8 close to this edge. Thereby the opening 8 is positioned at a distance from the edge 2 substantial ly corresponding ro the inner diameter in the annular portion 6 of the hinge member. The straight portion 7 is passed through an opening in the second sheet member 4 and is rotatably but axially non-slidably mounted in said opening in that the legs of the straight porti n 7 are folded in opposite directions at the opposite side of the second sheet member. Thereby it is possible to use a common split pin of standard type as hinge member.As is shown most clearly in Fig. 1 the sheet member 1 is movable in different direction relative to the second sheet member 4. From the position shown with full lines the sheet member 1 is pivotable 180 around a pivot axis situated adjacent the edge 2, which in turn ha contact with or is positioned at a very small distance from the planar surface 3 of the second sheet member 4. Further the sheet member 1, as also shown in Fig. 1, is pivotable around an axis that is perpendicular to the planar surface 3 and passes through the opening in said surface. This means that the hinge according to the in¬ vention gives the sheet member 1 very great mobility rela- tive to the second sheet member 4.The invention is of course not limited to the em¬ bodiment described above, but changes may be made within the scope of the accompanying claims.O'.PI | Claims :1. Hinge for connecting an edge (2) of a sheet member (1) to a preferably planar surface (3), characterized in that a hinge member (5) having an annular portion (6) and a straight portion (7) extending substantially radially from the annular portion is arranged with a portion of the sheet member (1) between the edge and an opening (8) close to the edge extending through the annular portion (6) and with the straight portion (7) rotatably but axially non- -slidably mounted in an opening in the planar surface (3). 2. Hinge according to claim 1, characterized in that the opening (8) in the sheet member (1) is positioned at a distance from the edge (2) of the sheet member sub¬ stantially corresponding to the inner diameter of the annular portion (β) of the hinge member (5)- 3- Hinge according to claim 1 or 2, characterized in that the hinge member (5) comprises a wire or the like bent to open annular shape, the ends of the wire being bent to parallel legs and extending substantially radial¬ ly relative to the annular portion (6) in order to form the straight portion (7).4. Hinge according to claim 3j where the planar sur¬ face comprises one surface of a second sheet member (4), characterized in that the hinge member (5) is mounted in the opening in the planar surface in that the legs (7) are bent in different directions on the opposite side of the sheet member (4). | LUNDBERG H; PRIMUS SIEVERT AB | LUNDBERG H |
WO-1979000506-A1 | 1,979,000,506 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | G01B9 | G02B27 | G01B9 | G01B 9/02P | INTERFEROMETER SYSTEMS | In a Michelson interferometer system arranged to give four output interferograms, two at each orthogonal direction of polarisation, the reflection and transmission coefficients of the interferometer beam splitter (10) at the two polarisation directions are chosen so that the ratios of the a.c. component to the d.c. component are equal in three of the interferograms. Difference signals derived from the three interferograms are suitable for use with an automatic, reversible, fringe counting system. | INTERFEROMETER SYSTEMS This invention relates to displacement-measuring interferometers, more especially to Michelson interferometers arranged to provide an output suitable for use with an automatic reversible fringe counting system. Use of a reversible fringe counting system allows automatic correction for any vibration or retraced motion. Conventional systems require two electrical input signals which vary sinusoidally with path difference in the interferometer, which are in phase quadrature, and which ideally have fixed amplitudes.Usually the signals are provided by photodetectors each arranged to sense an interferogram, that is, a part of an interference fringe pattern which changes as the optical path difference in the inter erometer changes. In many prior art arrangements, interferograms are generated which each comprise a regularly alternating component, which will be referred to as an a.c. component and which is dependent on path difference between its two constituent light beams, and a component which will be referred to as a d.c. component which does not alternate regularly and does not depend on the path difference.The magnitude of the d.c. component depends on variations in the alignment and relative sizes of the interfering beams, attenuation in one or both interferometer arms, losses due to limiting apertures, and on intensity fluctuations of the light source, so that this component cannot be removed by simple subtraction. If the d.c. component increases to a certain level, operation of the fringe counting system may not be possible.In U.S. Patent No. 3.771.875i Russo, an arrangement is disclosed in which three interferogram signals are provided which can be combined by sum and difference to give two purely a.c. components with no d.c. contribution. However, in theMichelson interferometer, in the measuring arm the radiation is at one direction of polarisation, and in the reference arm it is at the orthogonal direction of polarisation. The disadvantage of this is that the interferometer beam splitter must be constructed so that an area of its surface is polarising and the remaining area is non-polarising; further the non- polarising area must have values of reflectance and transmittance which are the same for each state of polarisation; this is a difficult condition to achieve.It is an object of the-invention to provide an interfer¬ ometer system capable of supplying two signals which vary sinusoidally with fixed amplitude as a function of path difference, which are in phase quadrature, in which any signal level changes not related to path difference are substantially eliminated, and in which the interferometer beam splitter is relatively easy to make. According to the invention, an improved interferometer system comprises: a Michelson interferometer comprising an interferometer beam splitter and two reflecting means arranged to receive radiation from opposite sides of the beam splitter and to return radiation to those sides whereby two exit beams of radiation are provided, one from each side of the beam splitter; a beam splitting and polarising means arranged to receive one exit beam and to separate the received radiation into radiation at two orthogonal directions of polarisation whereby two optical interferograms are provided; ' means arranged to receive the other exit beam and to separate from it radiation at one of said orthogonal directions of polarisation whereby a third optical interferogram is provided; the third interferogram being in phase quadrature with one of the first and the second interferograms, and being in antiphase with the other of the first and the second interferograms; characterised in that the interferometer beam splitter has for radiation at each orthogonal direction of polarisation reflection coefficients on its two faces which are equal, and has for radiation at one orthogonal direction of polarisation a transmission coefficient which is equal to its reflection coefficient; The effect of this equality of the coefficients is that, as will be explained in detail below, three interferograms can be provided having the same ratio of the a,c= τo the doC. component. It has been stated that the three interferograms must be in a phase quadrature or antiphase relationship with one another. While the system operates most effectively, so far as the signal-to-noise ratio is concerned, frhen the interfer-O n O ograms differ in phase by, ideally, 90 and loO , the system can operate when the phases differ considerably from the ideal situation. Depending on the accuracy required, the quadrature n O O relationship may be from 09 to 91 with no significant o o decrease in accuracy, may be from 75 ° 10 if lower accuracy is acceptable, and the system may still be operable when the phase difference is 50 or 130 .Further, it has been stated that three of the reflection and transmission coefficients of the interferometer beam splitter must be equal. While the tolerance in this equality is not as wide as the tolerance on phase relationships, it is not essential for operation of the system to have precise equality, although this will obviously be the preferred condition.In one arrangement of the interferometer the two reflecting means each comprise a plane reflector, and the means to receive the other exit beam comprises a further beam splitter arranged to reflect that beam to a second beam splitting and polarising means. Four interferograms are available with this arrangement; and three are selected, depending on which coeff cients of the interferometer beam splitter have been equalised_ Tr>e reflectors will usually be plane mirrors. In another arrangement of the interferometer the two reflecting means each comprise a retro reflector such as a corner cube, and the means to receive said other exit beam comprises a polariser arranged to allow passage of light in one of the two orthogonal directions. In practice the use of corner cubes is preferred because the system is insensitive to tilt of the reflectors and light is not reflected back to the source. The corner cubes can be coated so that the reflections do not introduce unwanted polarisation effects.Regarding the requirement that one interferogram is respectively in phase quadrature and in antiphase with the other two interferograms, this may be achieved bys-(a) arranging that the interferometer beam splitter provides the required phase difference;(b) the combination of an interferometer beam splitter that would normally produce a lδO or zero degree phase difference between reflected and transmitted orthogonal polarisations, with an eigth-wave plate in the optical path between the inter erometer beam splitter and one of the plane reflectors, radiation passing through the plate twice;OMPI_ (c) the combination of an interferometer beam splitter providing a l8θ or zero degree change with a quarter-wave plate in the optical path between the interferometer beam splitter and one of the corner cube reflectors, radiation passing through the plate only once; or(d) the combination of an interferometer beam splitter which produces a phase difference between the orthogonal o o polarisations whichdlif'ferrs from oO or 0 , with a complementary phase plate of thickness suitable for either one or two passages of the radiation so that the sum of the phase changes gives phase quadrature.Although three interferograms have now been provided in which the ratios of the a.c. component to the d.c. component are equal, it is a preferred but not essential further condition that the overall magnitudes of the three interferogram signals are equal. The interferograms are usually sensed by respective photosensitive detectors, and it is preferable if these detectors can be coupled to amplifiers having equal gains so that any electronic drift will tend to be the same for each signal. This condition can be achieved by the use of a variable optical attenuator between the interferometer outputs and each photocell; in this case the light beam illuminating the interferometer must comprise components at the said two orthogonal directions of polarisation of approximately equal magnitude. Alternatively, when corner cubes are used, the relative intensities of light in the two orthogonal directions of polarisation can be adjusted to provide three interferogram signals of equal magnitude.The invention will now be described by way of example with reference to the accompanying drawings in which:-Figure l(a) illustrates an interferogram signal having optimum fringe contrast;Figure l(b) illustrates an interferogram having reduced fringe contrast; Figure 2 illustrates an interferometer according to the invention;Figures 3(a), 3(b) and 3(c) illustrate the effect of subtracting two pairs of signals;Figure 4 shows a full optical system incorporating an interferometer according to the invention;Figure illustrates a full optical system using corner cubes in place of plane reflectors in the interferometer; andFigure 6 shows an automatic gain control system,Figure l(a) illustrates the output of a photodetector arranged to sense an interferogram. As the path difference between the two interfering beams changes, the output varies between zero, corresponding to complete absence of light, and a maximum on an arbitrary scale. This represents a perfect situation.In practice, the output is typically as shown in Figure l(b) on the same arbitrary scale; the output signal of the photo- detector varies between a maximum, which, is less than in the perfect arrangement, and a minimum which is well above the zero level and is due to background illumination. The signal can be regarded as an a.c. component of constant maximum amplitude superimposed on a constant d.c. level. (Normally, neither component will have a constant value).The problems of using such output signals in conjunction with automatic fringe counting systems have been explained above. Figure 2 illustrates schematically an interferometer according to the invention comprising a dielectric intefer- ometer beam splitter 10, and two plane reflectors 12, 14, arranged as a conventional Michelson interferometer. The apparatus further comprises an eighth-wave-plate 16 in one of the optical paths, a further beam splitter 18, and two polarising beam splitters 20, 22.An illuminating light beam 24, for example from a frequency- stabilised laser (not shown) passes through the further beam splitter 18 into the Michelson interferometer, and the further beam splitter also receives one exit beam from the Michelson interferometer and reflects it to the first polarising beam splitter 20. The second polarising beam splitter 22 receives the other exit beam directly from the Michelson interferometer. The entire interferometer according to the invention is indicated by reference numeral 8. The polarising beam splitters 20, 22, separate the light incident on them into two orthogonally polarised components. P and S, the letters referring to polarisations respectively parallel and perpendicular to the plane of incidence at the beam splitter 10. Each component contains contributions from beams which have travelled through the Michelson interferometer by different routes, and therefore interfere to form interf rograms, which may be numbered from 1 to 4 as shown.The combination of the dielectric beam splitter 10 and the eighth-wave plate l6, through which light passes twice, ensures that the interferograms formed by orthogonal polarisations at o each output at 90 out of phase, while the interferograms o for the same polarisations at the different outputs are loO o out of phase. For example, interferograms 1 and 4 are 90 out of phase, and interferograms 1 and 2 are l8θ out of phase.If ct and α are the interfering amplitudes in each __< inter erogram and Δ is their phase difference, then at any part of the overlapping light distributions the resultant intensity is given by:- I = α 2 + α 2 + 2α a cos Δ (l)1 2 1 2The intensity of the background illumination is given by2 2 α•_ + °o wni° determines the d.c. component; the maximum intensity change due to variations of Δ is 4a α , and the maximum a.c. component therefore has a peak-to-peak value of 4^ α. Thus in each interferogram, the ratio of the a.c. to the d.c. component is determined by the root mean squares of the interfering signals divided by the sum of these signals =. The d.c. components due to non-overlapping areas of the beams are, for the moment, neglected. jN NiB. In optics, signals are referred to on the basis of their intensity, which equals the square of the amplitude. In electronics, signals are referred to by the value of their amplitude./ The values of α depend on the reflection and transmission coefficients of the interferometer beam splitter, depending on the path travelled by the interfering beam, and on beam expansion, alignment, etc.In the interferometer beam splitter 10, let the face nearer the further beam splitter 18 be the air side and the face nearer the reflector l4 be the substrate side , and let the reflectance and transmission coefficients of the interfer¬ ometer beam, splitter be represented by R and T. The six coefficients of the interferometer beam splitter at the two orthogonal directions of polarisations are set out in Table I below Figure 2. Each value of 3 is dependent on two coefficients, either on two different coefficients, or twice dependent on the same coefficient. For example for a beam having polarisation direction S which is reflected by the interferometer beam splitter 10, reflected by reflector 12, reflected again by beam splitter 10 and passes to the polarising beam splitter 20, the amplitude a is given by:- = A R (2)1 I s where A is the initial amplitude of the S component and k is terra dependent on beam expansion, alignment, attenuation etc. For a P component beam transmitted by beam splitter 10. reflected by reflector l4 and reflected by beam splitter 10, the The amplitudesα ando for the interfering beams in all four interferograms are given in Table II below Figure 2. where k is a term similar to k and the initial amplitude of the P-component is also A. The values of k and k will be the same only if the beams are of the same size and perfectly aligned, and if there is no relative attenuation. The effect of the further beam splitter 18 is ignored; this does not affect the reasoning. The polarising beam splitters are assumed to be perfect.2 2 It can be seen from Table II that the values °\ + a1 2 for the background illumination and the ratio of a.c. to d.c. components are different for each interferogram. If all2 2 values of α + a and the a.c. components were equal, the d.c. component could be removed by subtraction of pairs of signals. The sinusoidal components would not be removed because they are not in phase. Inspection at Table II shows that three interferogram signals all having equal ratios of a.c. to d.c. components can be provided by selecting the values of some of the 6 coefficients of the interferometer beam splitter 10. Hence it is easy to obtain three signals having equal d.c. components and also equal a.c. components, for example by suitable orientation of the plane of polarisation of the input beam. When this condition is achieved, it can be shown that the d.c. components of the three signals due to non-overlapping areas~of the-iήterfering. beams are also equal. „It_.is:be:_;ieved that- thisihas.-.noii -previously- been realised, and this selection is the basis for the present invention.Two alternative possibilities exist:-(a) for equality in interferograms 1, 2 and 3.R = R 1 = T and R = R 1 (4) s s s p p(b) for equality in interferograms 2, 3 and 4,R = R 1 = I and R = R 1 (5) p p p s sThe dielectric beam splitter 10 is selected to meet one of the two conditions (a) or (b), and from the three output signals from the photodetectors sensing the appropriate interferograms, two pairs of difference signals are provided, and supplied to a conventional fringe counting system.Usually, the properties of dielectric beam splitters are such that the reflection coefficients on opposite sides of the beam splitter are equal for the same plane of polarisation. Thus the interferograms 2 and 3 will in any case comprise signals having the same ratio of the a.c. to the d.c. component.It follows that it is usually necessary to deliberately select an interferometer beam splitter in which the coefficients of transmission and reflection are equal for one of the two orthogonal polarisation states; this determines whether interferogram 1 or interferogram 4 is used.It is possible for all six coefficients to be equal but beam splitters with this property are not readily available or easy to manufacture whereas it is fairly easy to equaliseR and T for one polarisation.The effect of subtracting two pairs of signals, each having a constant ratio of the a.c. to the d.c. component and with the same magnitude is illustrated in Figure 3- The upper part, Figure 3(a), shows by the chain-dotted, dotted and full lines respectively the outputs from photodetectors arranged to sense the interferograms 1, 2 and 3. The phase difference o between interferograms 1 and 3 and between 3 and 2 is 90 , because interferogram 3 is produced by the polarisation ortho- gonal to that producing 1 and 2; this condition is imposed by the use of a dielectric interferometer beam splitter (which gives a l8θ phase difference between interferograms 1 and 2) plus an eighth wave plate in one interferometer arm.It is essential to subtract signal pairs which differ in phase by 90 , so that the resultants of the subtracted signals also differ in phase by 90 , and can therefore be presented to the fringe counting system. This is illustrated in the vector diagrams in Figure 3(b) - subtraction of the pair of signals 3 and 1, and the pair of signals 3 and* 2 provides resultant signals (3-1) and (3-2) which differ in phase by 90 . This can also be seen in Figure } (c ) which represents by the chain- dotted and full lines the respective outputs of two subtractor units each arranged to subtract one pair of signals. The subtractors provide a pair of subtraction output signals which vary about a zero level, i.e. which have no d.c. component, and which are in quadrature; this pair of signals fulfils the conditions required by an automatic fringe counting system. With variation about a zero, a suitable constant triggering level is easily chosen. A full optical system, incorporating an interferometer according to the invention and an automatic fringe counting system is shown in Figure 4 in which a beam of light 24 from a helium-neon frequency stabilised laser 26 is incident on an interferometer 8 according to the invention through a quarter wave plate 28 and a plane polariser 30; this combination provides an input beam having a plane of polarisation which can be adjusted with respect to the interferometer 8 so that it contains approximately equal components in the P and S directions, which is independent of the polarisation state of the light emerging from the laser 26.BU R£ i _0MPI ~ The four interferogram outputs 1 to 4 of the interfer¬ ometer 8 are each sensed by a photodetector 3 , ~2. , 33. 34 respectively. The outputs of photodetectors 31 and 33 and the outputs of photodetectors 32 and 33 are connected to respective subtractor units 36, 38 which each provide an output which is connected to an automatic fringe counting system 4θ of conventional type, which can count fringes corresponding to movement of one of the interferometer reflectors 12, l4. The count is not affected by vibration etc., and reversal of the movement is possible.For reasons explained above, it is convenient if the photo¬ detectors receive signals of equal magnitude. One method of providing such signals is to arrange variable attenuators 6l, 62, 63, 64 (shown dotted) between the outputs of inter erometer 8 and the photocells 31, 32, 33 , 34. The settings of the attenuators can be adjusted until three equal signals are supplied to the subtractors 36 and 38.Figure 4 illustrates an optical system operating on condition (a), given by equation (4); therefore the output of photodetector 34 is not used. If condition (b), given by equation (5) was used, the appropriate pairs of photodetectors would be connected to the subtractor units.An alternative interferometer according to the invention is illustrated in Figure 5. comparison with Figure 2 will show that the plane mirrors 12, l4 have been replaced by corner cubes 42, 44, and the polarising beam splitter 20 has been replaced by a plane polariser 46. Otherwise, like components have been give the same reference numerals. Selection of interferogram 1 or interferogram 4 is accomplished by changing the orientation of the polariser 46.It is an advantage of this arrangement that, instead of use of attenuators as in Figure 4, the interferogram signals may be equalised by altering the plane of polarisation of the polariser 30, so that the two orthogonal components in the incident beam are unequal.. With either the Figure 2 or the Figure 5 arrangement of the interferometer, it may be a requirement that the fringes are sub-divided, and sub-divisions of a fringe counted. This can be achieved by setting the trigger levels at values other than zero, but for satisfactory performance the two final o signals having 90 phase difference must have constant and equal maximum amplitudes as well as a zero d.c. component. In order to maintain the equal amplitude condition, an automatic gain control system can be used. A suitable system is illustrated in Figure 6.The photodetectors 31. 32, 33 . are connected to respective amplifiers 4l, 42, 43; amplifiers 4l and 43 are connected to difference amplifier 44 and amplifiers 42 and 43 are connected to difference amplifier 46. The difference amplifiers are connected through respective squarers 48, 50 to a summing amplifier 52, the output of which is connected through a square-rooter ^k to one input of each of two ratio amplifiers 6j 58, the other inputs being supplied directly from the difference amplifiers 44, 46. Suppose a_ is the amplitude of the a.c. signal and b_ is the amplitude of the d.c. signal; then the output of each amplifier 4l, 42, 43 will comprise both a_ and b_ components. When the output signals of the difference amplifiers 44, 46, are squared by squarers 48, 0, and summed by summing amplifier 52, the sum comprises a signal proportional to the o square of the amplitude because the phase difference of 90 between each pair of difference signals reduces the sum to2 2 ___ the addition (sine + cosine ) x amplitude . Taking the square root of this sum provides a signal proportional to the peak amplitude of the quadrature input signals and which can be used with the respective ratio amplifiers 56, 58 to provide two .output signals in phase quadrature and of constant magnitude. These signals can be supplied to the automatic fringe counting unit 40. It will be appreciated that the function of the subtractor units 36, 38 in Figure 4 have been incorporated into the automatic gain control circuit of Figure 6.It is to be understood that the apparatus described with reference to the drawings may be modified in several ways. For example, in place of one of the plane mirrors 12, l4 in Figure 2, a reflecting surface of a workpiece may be used to derive one or two of the three required interferograms; alternatively, a tilted plane workpiece surface plus a lens may replace one of the corner cubes 42, ,44, -in Figure 5.In these arrangements, it is particularly advantageous that the interferometer system can operate when the a.c. signal has fallen from its maximum value by a considerable factor; the factor may be as great as . The invention has been described with reference to the use of a stabilised laser as a light source. This is not essential; an unstabilised laser or a line source such as a cadmium lamp may be used as a source, provided the working distance of the Michelson interferometer is within the coherence length of the chosen source.Several other changes are possible. Instead of using polarising beam splitters, references 20 and 22 in Figure 2, a non-polarising beam splitter and two polaroids may be used in each position. By the incorporation of an additional plane reflection in the Michelson interferometer to give parallel working and reference beams, a tilt-measuring system can be provided. Instead of a λ/8 plate, which is usually extremely fragile, a 3^/8 plate may be provided. When the additional plane reflector described above is used, it may be designed to provide the required phase conditions.O Pj. . It would also be possible to arrange the Michelson interferometer so that the beams between the interferometer beam splitter and the reflecting means are at an angle other than o90 without affecting the operation of the invention. The output from the light source may be circularly polarised by attaching a circular polariser to the source or the interferometer with the advantage that rotation of the source and/or the interferometer system about the axis of the input light beam or axes parallel to it have, in practice, little effect on the instrument performance. In this.arrangement the positions of the polariser 30 and the λ/4 plate 28 in Figure 5 are interchanged. If the source 26 is already polarised as in the case of most frequency stabilised lasers and lasers with Brewster windows, the polariser 30 may be dispensed with. The λ/4 plate is then suitably orientated with respect to the plane of vibration of the source. However optical attenuators as shown in Figure 4 or different light detector amplifier gains are required.The two antiphase signals may also be subtracted to provide a d.c.-free signal. This and the two other subtractor signals already available and free of d.c. components can be added or subtracted in all the possible combinations to provide signals or intermediate phases suitable for fringe - sub-'di'vilsion. 1 In turn this may be applied indefinitely by similarly adding and subtracting the intermediate phase signals but in practice will be limited by the signal to noise ratios. A method of producing intermediate phase signals has been described in the specification of U.K. Patent No. 1,345,204 but this has the disadvantage of requiring a number of photodetectors equal to the number of signals and in addition the signals are not free of d.c. components.The interferometer will usually be used to measure distance, but by measuring the frequency of the fringes in the interferograms, a velocity measurement can be made. | CLAIMS 1. An improved interferometer system comprising: a Michelson interferometer comprising an interferometer beam splitter (lO) and two reflecting means (12, l4) arranged to receive radiation from opposite sides of the beam splitter and to return radiation to those sides whereby two exit beams of radiation are provided, one from each side of the beam splitter; a beam splitting and polarising means (22) arranged to receive one exit beam and to separate the received radiation into radiation at two orthogonal directions of polarisation whereby two optical interferograms are provided; means (l8, 20) arranged to receive the other exit beam and to separate from it radiation at one of said orthogonal directions- of polarisation whereby a third optical interferogram is provided, the third interferogram being in phase quadrature with one of the first and second interferograms, and being in antiphase with the other of the first and second interferograms; characterised in that the interferometer beam splitter (10) has for radiation at each orthogonal direction of polarisation reflection coefficients on its two faces which are equal, and has for radiation at one orthogonal direction of polarisation a transmission coefficient which is equal to the reflection coefficient. 2. An interferometer system according to Claim 1 in which the two reflecting means (12,l4) each comprise a plane reflector, and the means to receive the other exit beam comprises a further beam splitter (l8) arranged to reflect that beam to a second beam splitting and polarising means (20).3. An interferometer system according to Claim 1 in which the two reflecting means each comprise a retro-reflector .(42., 44) and the means to receive said other exit beam comprises a polariser (46) arranged to allow passage of light in one of the two orthogonal directions.4. An interferometer system according to Claim 1 further comprising three photodetection means (31. 32, 33 arranged to receive the three interferograms and to provide three electrical signals in the same phase relationship as the interferograms from which they are derived, and signal subtraction means (36, 38) arranged to subtract the signal pairs which are in phase quadrature, whereby two alternating output signals are provided having zero d.c. component. 5» An interferometer system according to Claim 4 further comprising means to maintain the two output signals at constant and equal maximum amplitudes.6. An interferometer system according to Claim 5 in which the means to maintain the two output signals at constant and equal maximum amplitudes is an automatic gain control system which comprises three amplifiers (4l, 42, 43) connected one toO each photodetection means; two difference amplifiers (44, 46) to which pairs of amplifier output signals in phase quadrature are connected; squaring and summing means (48, 50, 5 ) connected to the outputs of the difference amplifiers; square-rooting means (54) connected to the output of the summing means; two ratio amplifiers (56, 58) both connected to the output of the square-rooting means and respectively connected to the outputs of the difference amplifiers and automatic fringe counting means (4θ) connected to the outputs of the ratio amplifiers.-BUREAUO PI . r ipn | DOWNS M; NAT RES DEV; RAINE K; NAT RES DEV CORP | DOWNS M; RAINE K |
WO-1979000510-A1 | 1,979,000,510 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | H02N13 | null | H01L21, H02N13 | H01L 21/673, H01L 21/683C2, H01L 21/687S16, H02N 13/00 | SUBSTRATE CLAMPING TECHNIQUES IN IC FABRICATION PROCESSES | Electrostatic clamping techniques for use in clamping substrates in various semiconductor fabrication processes are disclosed. One embodiment takes the form of a substrate support plate (5) which has deposited on its working face two layers (12A, 12B) of thermally conductive, electrically insulative RTV silicone, between which layers is located an interdigital type printed circuit capacitor (7) energized by a DC source (V) in the kilovolt range. Secured to the back surface of the support plate (5) is a water-cooled jacket (6) with the entire assembly adapted for location in the incident ion beam (2) and having good thermal dissipation properties. An alternate implementation utilizes an alumina support plate on which the capacitor of aluminum composition is deposited by vacuum evaporation, and the exposed capacitor surface is rendered insulative by oxidation. A second embodiment employs a substrate hold down plate (15) which has on its working face an interdigital type printed circuit capacitor (18A, 19A) covered by an outer layer (21) of electrically insulative, compressible, resilient, RTV silicone. The capacitor (18A, 19A) is an electrostatic field generator energized by a DC source in the kilovolt range. In a typical application, there is secured to the back surface of the hold down plate (15) a water-cooled jacket with the entire assembly adapted for location in the incident ion beam and having good thermal dissipation properties. The substrates to be clamped are supported in a plate-like carrier (30) having flanged apertures (31) for laterally confining the substrates. The carrier is secured to the hold down plate (15), thereby bringing the substrates into proximity with the electrostatic field generating capacitor (18A, 19A), and also masking those areas of the hold down plate not covered by the substrates. When the capacitor (18A, 19A) is energized, the substrates are attracted towards it. The outer silicone layer (21), being compressible, provides improved proximity of the clamped substrate to the hold down plate (15). For facilitating release, the carrier incorporates a manifold (35) designed to supply gas under pressure to the substrates to free them from the hold down. | SUBSTRATE CLAMPING TECHNIQUES IN IC FABRICATION PROCESSESBACKGROUND OF THE INVENTIONIn a typical semiconductor micro-fabrication process, e.g., an ion beam etching operation, a substrate is pro¬ cessed by radiation in a high vacuum chamber. For example, the substrate may be etched for which purpose it is often coated with a photoresist pattern st.ch that the areas to be etched are devoid of the photoresist material which thus functions as a stencil. The substrate (which may be con¬ ductive, semiconductive or insulative) is then mounted on a support and exposed in a high vacuum to the ion beam which is controlled to etch or mill away the exposed areas of the substrate to a desired depth.One problem limiting the use of this technique is re¬ lated to the danger of thermally caused degradation of the photoresist layer. This problem requires in many applica¬ tions the use of a water-cooled substrate support serving as a heat sink. In such an arrangement it becomes necessary to insure good thermal conductivity between the substrate being processed and the water-cooled support. It is a com¬ mon expedient to provide this conductivity by use of a grease which thereby provides a thermally conductive path of substantially greater cross sectional area than would otherwise obtain in an essentially three point contact be¬ tween the substrate and the support to which it is attached.hile the use of grease is an acceptable procedure in laboratory type applications, it constitutes a limitation where production ion-etching and other production ion beam processes are desired. One proposed amelioration of the problem is described in British Patent Specification 1,443,215. In that refer¬ ence an electrostatic clamping arrangement is disclosed wherein a wafer or other object to be exposed to an ion beam or other radiation is secured to its support by the use of an electrostatic field.To establish the field a voltage source is connected between the support and the substrate or wafer to be treated.This approach (and a related one shown in Wardly, Ele trostatic Wafer Chuck for Electron Beam Microfabrication, 1506 Rev. Sci. Instrum.. Vol. 44, No. IV, October 1973), appears to have two disadvantages in some applications. First of all it requires making electrical contact with the substrate being treated. Secondly, the mode of creat¬ ing the electrostatic field can cause interference with the beam process (ion, plasma, electron or other radiation) in certain circumstances. In some cases this interference can be overcome but this can require additional connections between the ion beam grid system and the support and vol¬ tage supply.It is accordingly an object of the invention to pro¬ vide a system which ameliorates the shortcomings associated with the aforementioned approaches.It is a further object of the invention to provide a substrate clamping technique which does not require elec¬ trical contact with the wafer substrate or other element being processed and which also does not complicate the bea forming and controlling system.It is another object of the invention to provide a system which is particularly amenable to mass production •5-techniques because it does not depend upon the use of potentially contaminating grease nor on the need to make electrical contact with the wafers being processed.It is still another object of the invention to provide a substrate clamping technique with improved clamping ac¬ tion which provides better heat dissipating properties, and improved loading, unloading and through-put character¬ istics.Other objects will be apparent in the following des- cription and the practice of the invention.SUMMARY OF THE INVENTIONOne embodiment of the invention which achieves these objects, and other objects apparent in the following des¬ cription and in the practice of the invention, may be sum- marily and generally characterized as a substrate clamp comprising a thermally conductive support, multi-electrode capacitor means incorporated in the support and having at least two terminals for connection to a voltage source, and electrically insulative, thermally conductive means oriented to insulate said capacitor from said substrate, while providing* thermal conductivity between them.A second embodiment of the invention relates to a substrate clamp having a thermally conductive support and electric field generating capacitance with at least one electrode associated with the support, and particularly to an improvement thereto comprising a compressible layer between the capacitance and the substrate to be clamped for providing improved thermal conductivity between them. A further feature of this embodiment of the invention com- prises a substantially planar substrate carrier having a plurality of apertures, each for laterally constraining a substrate, the carrier being configured for attachment to the support in such manner as to bring the substrates into proximity with the support and mask the areas of the sup¬ port not covered by the substrates. A still further fea- ture involves a pneumatic release system in which gas unde pressure is applied via a manifold in the carrier to the clamped substrates to release them.BRIEF DESCRIPTION OF THE DRAWINGSServing to illustrate exemplary embodiments of the invention are the drawings of which:FIGURE 1 is a schematic elevational view illustrating the electrostatic clamp of the invention in an ion beam high vacuum system, it being understood that the invention will serve in other applications as well; FIGURE 2 is a schematic plan view of the electrostati clamp on an enlarged scale;FIGURE 3 is a schematic elevational and partly sectio al view of the clamp with a substrate mounted thereon, on a still larger scale; FIGURE 4 is an enlarged cross-sectional schematic fragmentary view of the hold down plate of a second embodi ment;FIGURE 5 is a plan view of the second embodiment; and FIGURE 6 is an exploded and cross-sectional view show ing the substrate carrier of FIGURE 5 in section along lines 6-6 of FIGURE 5, together with substrates and the hold down plate of FIGURE 5.DETAILED DESCRIPTION OF PREFERRED EMBODIMENTIn order to afford a complete understanding of the invention and an appreciation of its advantages, a descrip tion of two alternative and preferred embodiments is pre¬ sented below. The first embodiment is illustrated in FIGURES 1-3. Referring now to FIGURE 1, the system schematically illus¬ trated therein comprises an ion beam etching system which includes an ion beam source 1 for generating an ion beam 2 which is incident on a substrate 3 of semiconductive material such as silicon. The substrate 3 is mounted on a support 4 which includes an electrostatic plate 5 and connected thereto and in good thermal contact therewith, a water-cooled plate or jacket 6.Incorporated on the incident surface of electrostatic plate 5 is a printed circuit capacitor 7 having electrical terminals 8 and 9 which are connected via respective leads 10 and 11 to a source of DC voltage, V.FIGURE 1 illustrates the electrostatic clamp in an ion beam etching function, the source 1 including the usual grid structures, e.g., electron suppression and ion accel¬ eration grids, as well as an exit grid, neutralization grid and any other required beam controlling electrodes. The source 1 also includes an anode and hot cathode and may include a magnetic field for imparting epicycloidic trajec¬ tories to the emitted electrons.The ion source 1 also includes a source of gas such as neon or argon, and the entire system is enclosed within a high vacuum chamber. Examples of ion beam etching sys- terns are found in microetch systems sold by the assignee herein, Veeco Instruments Inc. (ion source 0313-901, power supply 0313-310; automatic pumping station VE 747).Further details of the printed capacitor 7 are shown in FIGURES 2 and 3. As shown therein the capacitor is of the printed circuit interdigital type and includes a first set of electrodes 8A connected to capacitor terminal 8 by way of a peripheral arcuate conductor segment 8B. Similarly, the oppositely polarized electrodes 9A are interdigitated with the plates 8A, and are connected by a printed arcuate segment 9B to capacitor terminal 9.A suitable material for forming the conductor pattern of the capacitor is Eccocoat CC2 silver ink spray sold by the Emerson and Cuming Company. In the exemplary embodi¬ ment the printed circuit pattern is in the order of about 1 mil thickness.As shown in FIGURE 3, the printed circuit pattern is sandwiched between a pair of layers 12A and 12B, the former being coated on the outer surface of plate 5. Each of the layers 12A and 12B is, in the exemplary embodiment, of a thickness of about 4 mils and is comprised of a compressibl electrically insulative, thermally conductive material. The preferred composition is a thermally conductive RTV silicone such as is marketed under the designation Eccosil 4952, sold by the Emerson and Cuming Company.As previously noted, the plate 5 is secured both mech¬ anically and with good thermal conductivity, to the water- cooled plate 6. To now insure good thermal conductivity between the substrate 3 being processed and the water- cooled plate, the printed circuit capacitor 7 is energized to create an electrostatic field which brings substrate 3 into good thermal contact with outer layer 12B.Since layer 12B is compressible and in intimate con¬ tact with layer 12A which is in turn in good thermal con¬ tact with plate 5, and since plate 5 is in good thermal conductivity with water-cooled base 6, excellent tempera¬ ture control is achievable. A voltage appropriate in the illustrated embodiment for achieving the requisite contact is in the neighborhood of about 1.5 kilovolts.\_. R E CMPI As shown in FIGURE 2, the voltage source which sup¬ plies the charge to capacitor 7 may be switched by use of switch S such that opening the switch disconnects the voltage source from the capacitor and discharges the latter thereby permitting release of the wafer being treated.In an alternate embodiment the support plate 5 may be fabricated of a thermally conductive electrical insu¬ lator such as alumina on which the capacitor 7 is deposited as by silk screening or vacuum evaporation. The need for layer 12A can thus be obviated.By forming capacitor 7 from aluminum, e.g. , by vacuum evaporation, and then oxidizing the exposed capacitor sur¬ face to form a thermally conductive, insulative layer, the layer 12B can also be excluded.The substrates which may be held in place by the electrostatic clamp may be conductive, semi-conductive, or electrically polarizable insulative devices. It should also be understood that one of the terminals of the capaci¬ tor may be a grounded conductive surface or joint.The system described above employs compressible means between the electrostatic field generating capacitor and the clamped object, illustratively a layer of silicone rubber. It has been found that the closer clamping which is achieved with such a compressible layer, provides im- proved thermal conductivity between the substrate and the heat sink, a key requirement in many semiconductor fabri¬ cating processes.An alternative and preferred embodiment which provides improved thermal conductivity between the substrate and the heat sink is illustrated in FIGURES 4-6. Other improve¬ ments involve the structure of the hold down plate assembly which incorporates the capacitor, and a substrate carrier which transports the substrates, brings them into the active region of the hold down plate, serves to mask the hold down plate regions not covered by the substrates, and incorporates a manifold to facilitate pneumatic re¬ lease of the substrates.Referring now to FIGURES 4-6, a support plate 15 is fabricated of a thermally conductive electrical insulator such as alumina on which the capacitor electrodes 18A, 19A are deposited as by silk screening or vacuum evaporation. Covering the printed capacitor is a hard overglaze 20 which may be, for example, porcelain. Covering the over¬ glaze is a compressible resilient layer 21, illustratively the RTV silicone previously described.The capacitor 18A, 19A takes the form previously described, and is energized as previously indicated. One of the terminals of the capacitor may be a grounded con¬ ductive surface or point, and one electrode of the capa¬ citor may be remote from the support.For transporting the substrates to the electrostatic clamp a disc-shaped carrier 30, FIGURES 5 and 6, is employ It includes six peripheral apertures 31 and a central aper ture 32 for holding the substrates to be clamped.Each aperture wall includes a flange 33 for supportin the substrate rim, a conical, outwardly flaring section34A on the incident beam side of the carrier, and a paral¬ lel-sided section 34B on the clamp side which surrounds and constrains the substrates.To provide a gas distributing manifold in the carrier there is recessed in the face thereof a main manifold chan nel 35 concentric with central aperture 32 and radial branOA. channels 36, each interconnecting the section 34B of center aperture 32 with the section 34B of a respective peripheral aperture 31.Also recessed in the face of carrier 30 is an inlet plenum 37 which communicates with main channel 35 and has an inlet port 38. The latter is threaded to receive a threaded plug (not shown) .In operation, carrier 30, loaded with substrates, is clamped to the substrate holder 14 by means of a suitable mechanical clamp.When voltage is applied across electrode 18A, 19A, the substrates are attracted to the compressible outer layer 21.To unload after the ion etch or other operation is completed, a source of gas under pressure is applied to port 38. The gas traverses inlet chamber 37, channel 35 and branches 36 to the edges of the loaded wafers where it acts to loosen them from the substrate holder.During the treatment process, the solid section of carrier 30 protects the hold down coating 21 from the effects of the treatment process; e.g., milling, etching or deposition.By way of example, the clamp 14 and carrier 30 are roughly 10 inches in diameter. The alumina layer of clamp 14 is 0.312 inches thick and consists of high density 99% pure; the electrodes 18A, 19A are 3-5 microns thick and the overglaze 18A is roughly .002-.004 inches. Resilient coat 21 is .015 inches thick. Carrier 30 is approximately 1/4 inch thick and fabricated from 304 stain- less steel. -10-It is clear that the above description of the pre¬ ferred embodiments in no way limits the scope of the pre¬ sent invention which is defined by the following claims. | WHAT IS CLAIMED IS:1. A substrate clamp for use in semiconductor fabri¬ cation systems comprising a thermally conductive electrically insulative support, multi-electrode capacitor means mounted on the support to establish an electric field and having at least two terminals for connection to a voltage source, and thermally conductive means oriented to electrically in¬ sulate said capacitor means from said substrate while pro¬ viding thermal conductivity therebetween.2. The clamp as defined in Claim 1 in which said ther¬ mally conductive means comprise thermally conductive coat¬ ing.3. The clamp as defined in Claim 1 in which said ther¬ mally conductive means comprise an oxide coating on said capacitor means.4. The clamp as defined in Claim 1 in which said support comprises an electrically conductive metallic layer coated with a thermally conductive silicone material.5. The clamp as defined in Claim 1 in which said support comprises a plate fabricated of an electrically insulative, thermally conductive material.6. The clamp of Claim 5 in which said material is alumina.7. The clamp of Claim 6 in which said capacitor means are comprised of aluminum and in which said thermally con¬ ductive means comprise an oxide coating on said capacitor means.■βΪJKcΛ^*. OMPI 8. The clamp as defined in Claim 1 in which said capacitor means comprise an interdigital capacitance.9. The clamp as defined in Claim 1 in which said thermally conductive means comprise a pair of layers be¬ tween which is sandwiched said multi-electrode capacity means.10. The clamp as defined in Claim 1 in which the electrodes of said capacitor means are in the order of about 1 mil thickness.11. The clamp as defined in Claim 5 in which said thermally conductive means comprise two layers of thermall conductive material, each of approximately 4 mils thicknes and between which said multi-electrode capacitor means is located.12. In a substrate clamp for use in semiconductor fab rication systems wherein the clamp comprises a thermally conductive support having capacitance for establishing an electric field, the improvement comprising a resilient compressible means between said capacitance and said sub¬ strate to be clamped for providing improved clamping.13. The clamp as defined in Claim 12 in which said resilient, compressible means comprise a thermally conduc¬ tive electrically insulative coating.14. The clamp as defined in Claim 13 in which said coating comprises silicone material.15. The clamp as defined in Claim 12 in which said resilient compressible means comprises silicone rubber material.I ΌREO.V. 16. The clamp as defined in Claim 12 in which said capacitance comprises an interdigital planar capacitance.17. The clamp as defined in Claim 12 in which said resilient compressible means comprise a pair of layers between which said capacitance is sandwiched.18. The clamp as defined in Claim 12 in which the electrodes of said capacitance are in the order of about 3-5 microns.19. The clamp as defined in Claim 12 in which said thermally conductive support comprises an electrically insulative material having said capacitance deposited thereon.20. The clamp as defined in Claim 19 in which said support comprises alumina.21. The clamp as defined in Claim 19 including an insulative overglaze covering said capacitance and on which said resilient compressible layer is provided.22. The clamp as defined in Claim 12 including a substrate carrier coupled to said support and having (1) a plurality of apertures for confining a plurality of said substrates; and (2) impervious sections for masking sections of said resilient layer not covered by the substrates.23. The clamp as defined in Claim 22 including gas duct means in said carrier configured to direct pressur- ized gas to said apertures for facilitating release of said substrates. | VEECO INSTR INC | BOLLINGER L; BRIGLIA D |
WO-1979000511-A1 | 1,979,000,511 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | H02G1 | B25B7 | H02G1 | H02G 1/08D | HAND TOOL FOR PULLING CABLES | A hand tool composed of two articulately coupled jaws (10, 12). The tool is to be used when pulling cables and/or wires by means of a draw spring or similar implement, when it receives and grips the draw spring and serves as a handle by means of which a fitter can insert the spring into and pull it out of a duct, for example. The jaws, when pressed towards each other, form between them a longitudinally oriented space (16) fitting the spring. Those parts of the jaws which then grip the spring and retain it by pressing against it from opposed sides are located between the joint (22) and the area to which pressure is applied by the hand. | Hand Tool for Pulling CablesThe present invention is concerned with a hand tool composed of two articulately coupled jaws and designed to receive and grip a draw spring or similar device for pulling cables and/or wires and to serve as a handle by means of which a fitter can easily insert the spring into and pull it out of a narrow passage, such as a duct.It is e ry common to use a draw spring when pulling wires through ducts. Such a spring normally consists of a fairly rigid, flat metal band, rolled up when in its normal state, which is passed through the duct and attached at the other end to the wire in question - such as an electrical conductor - which can then be easily pulled through the duct as the draw spring is retracted. Often, however, both the insertion of the draw spring into the duct and also its retraction there- from can be troublesome operations. Moreover, due to the form of the spring - flat and comparati ely stiff - it is hard to get a proper grip of it with the hand, and injuries to the hand often result from trying to propel or pull the spring too vigorously. It is therefore usual to employ tongs - such as drawing tongs or cutting pliers - to get a better grip of the spring. However, tongs have a tendency to slip easily and can also cause damage to the draw spring in the form of burrs. These increase the risk of hand injuries in case of subsequent manual handling of the spring. The main object of the invention is to provide a hand tool specially designed for wire pulling as described in the ingress hereto. For this purpose the tool should be easily applied, so that it can grip the draw spring either by one end thereof or by some portion between the ends. A hand tool of the type described above is to be chiefly characterized, according to the invention, by the fact that the jaws, when pressed towards each other, form between them a longitudinally oriented space fitting the spring, and that those parts of the jaws which then grip the spring and re¬ tain it by pressing against it from opposed sides are locate5 between the joint and the area to which pressure is applied by the hand.The jaws should preferably be detachably jointed, so tha the spring can be inserted between them irrespective of whether they are latched together or disengaged. It is ad-10 visable to link the jaws to each other by means of a chain, so that the jaws, although separable, will still always hang together during handling.The invention will now be described in closer detail in the form of an embodiment presented as an example, with refe15 rence to the figure in the drawing.The hand tool illustrated as an example in the drawing comprises two jaws 10 and 12. Jaw 10 comprises an elongated, relatively flat portion 14 which can be inserted in a groove 16 formed by the two. sides 18, 20 of jaw 12. The two jaws 1020 12 can be articulately latched together at their forward end For this purpose a pin (22) is provided, passing through jaw 10 and with its two ends 24, 26 projecting from the sides thereof. The pin ends 24, 26 can be inserted radially into corresponding slots 28, 30 in the sides 18, 20 of jaw 12 and25. the slots 28, 30 are so designed that the pin ends 24, 26 ar forced towards the forward extremities 32, 34 of the said slots when hand pressure is applied to the portion of the to - opposed to the latch end. The slots 28, 30 in the sides 18, 20 are paral 1 el and , in a lateral view, slightly curved. Thu30 the slots set out from the tops 36, 38 of the sides 18, 20 of jaw 12 towards the bottom piece 40 joining the sides, and then at points approximately midway between the said tops an the bottom piece 40 they curve upwards and forwards. When th assembled tool is compressed, the edge 42 of jaw 10 will be35 forced towards the bottom 40 of jaw 12. A draw spring (not illustrated) or similar object inserted between the jaws 10, 12 will then be gripped effectively.Jaw 10, as indicated in the figure, has a T-shaped sec-I °- V? . vV'X tion for a considerable part of its length and jaw 12 has a U-shaped section, matching the T-shaped section, for at least part of its corresponding length to function as a guide for jaw 10. Both the jaws 10 and 12 can with advantage be made chiefly of nylon but the forward portion of jaw 12 should be reinforced with metal details - components 44 and 46 in the figure - so that the pin ends 24, 26 come to bear on metal at the forward extremities 32, 34 of the slots 28, 30. The metal components 44, 46 are preferably fixed by means of rivets 48, 50. The rivets 48, 50 pass through the metal com¬ ponents 44, 46 and also through the sides 18, 20 adjacent thereto .A linking chain 52 of metal is attached by its ends to the pin 22 and the rivet 48 respectively of jaws 10 and 12. By this means the jaws 10, 12 will always hang together during handling, although capable of being unlatched from each other. The length of the chain 52 is not critical but should be between approximately 5 cm and 20 cm.As appears from the drawing, the contact face 42 of jaw 10 has a somewhat curved profile. This profile has a smaller radius of curvature than the corresponding contact face 54 of jaw 12. This arrangement ensures the wanted effective bearing pressure on the draw spring. Thanks to the choice of material and the consequent elasticity of the jaws it will further be possible, by applying greater pressure to the ends of the jaws, to increase the length of face transmitting pressure to the draw spring. The contact faces 42, 54 may be comparatively smooth and, since the material of the jaws 10, 12 is softer than that of the draw spring, there is no risk of damage in the form of burrs or the like on the draw spring while the latter is gripped between the contact faces 42, 54.Inasmuch as the draw spring, in its normal state, tends to assume a curved form, the rigidity of the spring will tend to separate the jaws 10, 12, by pivoting them about the pin 22, when the compressing force on the ends of the jaws ceases to operate. Hence by relaxing somewhat the pressure. of his hand on the tool , the fitter can slide the tool back or forth along the draw spring, which will be gripped once again when the pressure is increased.When the draw spring is to be gripped by one end it is inserted between the jaws 10, 12 at the forward end of the tool. In this case the jaws 10, 12 are latched together with the ends 24, 26 of the pin at the forward extremitites 32, 34 of the slots 28, 30. If the draw spring is to be inserted into the hand tool at some point between the ends - of the spring, the jaws 10, 12 are unlatched from each other. The spring is then placed in the groove between the sides 18, 20 of jaw 12, whereafter jaw 10 is latched onto jaw 12 by inserting the pin ends 24, 26 into the slots 28, 30 respect¬ ively.The hand tool described above is naturally susceptible of modification within the terms of the claims. Thus, the mechanism for guiding and retaining the jaws with respect to each other may be varied in many ways. The pivot pin may instead be fixed to the jaw that is provided with sides, in which case a corresponding slot is provided in the other jaw. The form of the jaws may be modified as desired so as to provide a good grip for the. hand whenever the tool is grasped . | CLA I MS1. A hand tool composed of two articulately coupled jaws (10, 12) and designed to receive and grip a draw spring or similar device for pulling cables and/or wires and to serve as a handle by means of which a fitter can easily insert the spring into and pull it out of a narrow passage, such as a duct; the tool being characterized in that the jaws (10, 12) , when pressed together, form between them a longitudinally oriented space (16) fitting the spring, and that those parts of the jaws which then grip the spring and retain it by pressing against it from opposed sides are located between the joint (22) and the area to which pressure is applied by the hand.2. Hand tool per Claim 1 , characterized in that the jaws (10, 12) are detachably coupled together so that the spring can be inserted between them whether they are latched together or disengaged.3. Hand tool per Claim 1 or 2, characterized in that the latch comprises a pin (22) passing transversely through the jaws (10, 12) at one end of the tool . 4. Hand tool per Claim 3 (when dependent on Claim 2) , characterized in that the pin (22) is fixed in one jaw (10) and that the ends (24, 26) thereof can be inserted radially into corresponding guide slots (28, 30) in the other jaw (12), in order to latch the jaws together. 5. Hand tool per any of Claims 1 to 3, characterized in that the face (42) of at least one of the portions of the jaws pressing on the spring has a curved profile.6. Hand tool per Claim 4, characterized in that the face (42) of at least one of the portions of the jaws pressing on the spring has a curved profile, and that the slots (28, 30) are so formed that the pin (22) is forced towards the forward extremities (32, 34) thereof as the jaws (10, 12) are pressed together . 7. Hand tool per any of Claims 1 to 6, characterized in that the jaws (10, 12) are arranged to guide each other when pressed together.8. Hand tool per Claim 7, characterized in that one jaw (10) has a T-shaped section for part of its length and that the other jaw (12) is provided with a U-shaped section, matching the T-shaped section, for. at least part of its corresponding length to function as a guide for the first jaw.9. Hand tool per any of Claims 5 to 8, characterized in that at least one of the jaws (10, 12) is somewhat yielding, so that the exertion of greater pressure on the jaws results in an increased length of face acting on the spring. AMENDED CLAIMS(received by the International Bureau on 25 June 1979 (25.06.79))1. A hand tool composed of two articulately coupled jaws (10, 12) and designed to receive and grip a draw spring or similar device for pulling cables and/or wires and to serve as a handle by means of which an electrican can easily insert the spring into and pull it out of, respectively, a narrow, passage, such as a pipe, a space (16) fitting the spring being defined between the jaws (10, 12) in the longi¬ tudinal direction thereof when they are pressed together, characterized in that said jaws (10, 12) which are detach- ably interconnected to enable the insertion of the draw spring either when they are interconnected or when they are separated, include contact surfaces (42, 54) , facing each other and extending along the greater part of the length of the tool , one contacting surface (42) having a smaller radius of curvature than the other surface (54) , and that at least one of the jaws (10, 12) is made from a resilient material , so that an increasing pressing of the jaws together means that a corresponding, greater length of the contacting surfaces of the tool is applied to the draw spring.2. Hand tool according to claim 1 , characte ized in that the articulated coupling comprises a pin (22) passing transversely through the jaws (10, 12) at one end of the tool . 3. Hand tool according to claim 3, characterized in that the pin (22) is fixed in one jaw (10) and that the ends (24, 26) thereof can be inserted radially into corresponding guide slots (28, 30) in the other jaw (12), in order to latch the jaws together. 4. Hand tool according to claim 1 or 2, characteri zed in that the face (42) of at least one of the portions of the jaws pressing on the spring has a curved profile.5. Hand tool according to claim 3, characterized in that the face (42) of at least one of the portions of the jaws pressing on the spring has a curved profile, and that the slots (28, 30) are so formed that the pin (22) is for¬ ced towards the bottoms (32, 34) thereof as the jaws (10, 12) are pressed together.6. Hand tool according to any of claims 1 to 6, characterized in that the jaws (10, 12) are arranged to guide..each other when pressed together.7. Hand tool according to claim 6, characterized in that one jaw (10) has a T-shaped section for part of its length and that the other jaw (12) is provided with a U- shaped section, matching the T-shaped section, for at least part of its corresponding length to function as a guide for the first jaw. | LARSSON K | LARSSON K |
WO-1979000514-A1 | 1,979,000,514 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | G07G1 | null | G07G1 | G07G 1/00B | CASH REGISTERS | A cash register in which the till is a front compartment (10) of the register-body (1), and is closed by a hinged (or sliding) lid (12) that opens in response to predetermined operation of a set of keys (9). The keys (9) are incorporated in the upper surface of the lid (12) with the lid (12) sloped downwardly towards the front of the body when closed, so as to incline the keys (9) forwardly. A releasable lock (14) holds the lid (12) closed against the action of a spring or gravity, the lock (14) being released to open the lid (12) under control of electronic circuits (23) that respond to data and instructions entered in the register via the keys (9). An interlock (28 to 31) inhibits release of the lock mechanism while the lid (12) is open. | Technical Field:This invention relates to cash registers of a kind having a set of keys for entering data and instructions into the register and a till that is opened in response to predeter- mined key-operation. Background Art:Cash registers of the above-specified kind conventionally have a till that is provided as a slideable drawer in the body of the machine, or in a separate unit on which the main body of the machine normally stands. At the conclusion of each transaction and following operation of the keys of the machine to enter data and instructions into the register, the drawer is driven out automatically to open the till and thereby enable the machine operator to deposit cash in the drawer and give change. After the deposit of cash and the giving of any change, the drawer is pushed back by the operator to close the till in preparation for further actuation of the keys in the next transaction. The weight of the drawer, especially when loaded with coin, can be substantial and -the task of repeatedly closing the drawer following successive transactions can become arduous unless mechanical assistance with closure is provided. The mechanism for holding the drawer closed and for effecting the automatic opening operation is, furthermore, required to be capable of securing the heavy drawer, accelerating it rapidly from rest and arresting it smoothly at the end of its travel. All these requirements add considerably to the cost, complication, bulk and weight of the cash register. Disclosure of the Invention: It is one of the objects of the present invention to provide a cash register in which the disadvantages referred to above are reduced or eliminated. More especially it is one of the objects of the present invention to simplify provision of the till. According to the present invention there is provided a cash register having a set of keys for entering data and instructions into the register and a till that is opened in response to predetermined key-operation, characterised in that the till is a compartment that is closed by a dis- placeable member, and that the said member is displaced in response to said predetermined key-operation to enable access to said compartment. The keys, which may be one or more electrical push¬ button or touch-responsive switches, may be carried by the said displaceable member. More especially, the said compartment may be provided at the front of the body of the cash register with the said member sloped downwardly towards the front of the body when closing the compartment, such that the set of keys is then inclined forwardly of the register so as to present them conveniently to the operator. The mounting of the key set on the member that closes the till has the particular advantage that both the key-set and the till-compartment can be located most conveniently for the operator, the keys being in such location while required for entry of data and instructions and then being displaced with said member to give access to the till compartment in that same location when use of the till is required.The said displaceable member may simply be a lid to the till compartment, and the set of keys may be convenient incorporated into the upper surface of such lid. The lid may be hinged, or may alternatively be arranged to slide from the position in which it closes the compartment to open the till. The use of a lid, whether hinged or other¬ wise, enables significant economy to be made in the provisi of the mechanism required to open the till rapidly at appropriate times during transactions. Furthermore such lid can be of very light construction and accordingly will in general require little expenditure of effort to close at the end of each transaction.The lid or other displaceable member may be urged by a spring or otherwise to move from the position in which it closes the till-compartment, a releasable mechanism which is for holding the said member in said position being released in response to the predetermined key-operation so as to open the till. An interlock may be provided to inhib\j IN *- - . release of the mechanism unless the said member occupies the position in which it closes the till; such an interlock reduces the risk of interferences with security of the till.Brief Description of Drawings:A cash .register in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Figures 1 and 2 are front and plan views respectively, of the cash register with its till closed;Figure 3 is a side view of the cash register of Figures ϊ and 2 with the till open;Figure 4 is a plan view of the till- compartment of the cash register of Figures 1 to 3; andFigure 5 is a partly schematic representation of part of the cash register, illustrating release mechanism used in conjunction with the till, .together with modifications of the cash register of Figures 1 to 3.Best Mode of Carrying Out the Invention: Referring especially to Figures 1 and 2, the body 1 of the cash register has feet 2 that enable it to stand firmly with an upper flat platform 3 of the body 1 horizontal. A display and printing head 4 of the register is mounted to the back of the platform 3 and serves to' provide transaction displays to the customer and operator, respectively, in windows 5 and 6. The head 4 additionally incorporates a printer (not shown) that is operable to print out trans¬ action data on sales slips, such as those indicated as slips 7, that are laid on the platform 3 and are pushed by the operator to enter beneath either side of the head 4. The printer is also operable to provide a print out of the transaction data for receipt and audit purposes, on paper strips 8 that are supplied from reels (not shown) accommoda within the machine. The machine also includes a set of electrical push¬ button switches or keys 9 for use by the operator to enter transaction data and instructions into the register. The keys 9 are individually marked with legend appropriate to their numerical or functional significance,_ and as each ite of transaction data is keyed into the register by the operator, it is displayed appropriately in bright numerical characters in the windows 5 and 6. Instructions on conduct of the transaction are also displayed to the operator in th window 6. The displays provided in the windows 5 and 6 are controlled by electronic circuits incorporated in the machi These circuits, which are conventional both as to their construction and programming, respond to actuation of the keys 9 to perform the calculations appropriate to the numer and functional information entered, and to effect display of the relevant sub-totals and totals in the windows 5 and When the total for the transaction is finally displayed, the machine directs the operator to key in the amount tendered by the customer. Once this amount has been entere the machine computes the amount of change to be given and indicates this in the display windows 5 and 6. Display of the amount of change due is followed automatically, and in accordance with normal practice, by opening of the machine till. (Change computation by the machine may be omitted and in this case the till opens immediately following displ of the transaction total.)The till of a cash register is conventionally provided as a slideable drawer in the body of the machine or in aUKOMPI -— -:\ - - -> separate unit secured beneath the machine body. The drawer remains closed until such time as an appropriate function key is actuated whereupon it is driven out automatically so as to open the till and enable the operator to enter received cash and give change as appropriate. However such a drawer adds considerably to the bulk of the machine and requires the provision of a somewhat complicated mechanism for holding the drawer closed and, more especially, for effecting the automatic opening operation. Such mechanism normally involves many (usually in excess of fifty, or even one hundred) individual components that are costly to provide and assemble. Furthermore the weight of the drawer, especially when loaded with coin, can be substantial, and the actuating mechanism must be capable both of exerting considerable force to drive the heavy drawer open rapidly, and of arresting it smoothly at the end of its travel. All these factors add considerably to the cost, bulk and weight of the cash registe_r, and it is one of the objects of the present invention to simplify the provision of the till. In this respect, and as illustrated in particular inFigures 3 and 4, the till of the machine of Figures 1 and 2 is provided in accordance with the present invention, simply as a compartment in the body of the machine that is closed by a flap or lid. Referring especially to Figures 3 and 4, the till- compartment 10 is in this example provided to the front within the machine body 1, and is divided appropriately into a multiplicity of .sections ϊl to receive individual denominations of coin and note. The compartment 10 has a lid 12 which is hinged to the body 1 on cranked arms 13, and which furthermore carries the set of keys 9. The keys 9 are incorporated into the upper surface of the lid 12 so as to be readily accessible to the operator when the lid 12 is closed (as illustrated in Figures 1 and 2) . In this respect the lid 12 when closed slopes forwardly down from the platform 3 so as to present the key set at a convenient inclination for the operator.A releasable lock 14 mounted in the front of the body 1 ~. - £ engages a catch 15 on the front-lip 16 of the lid 12 to hol the lid 12 down and thereby maintain the till-compartment 1 closed. The lock 14 is controlled from the electronic circuits of the register- to release the catch and allow the lid 12 to rise whenever the till-compartment 10 is to be opened (as illustrated in Figure 3) . Automatic opening of the lid 12 in response to release of the lock 14 may be effected by means of a spring, or (by suitable balance adjustment) under its own weight. Whichever is the case, closing of the till by the operator at the end of the transaction, involving in this case simply the closing down of the hinged lid 12 to re-engage the catch 15 with th lock 14, is less arduous than the action required to close the heavy drawer of a conventional cash register. The facility for opening the till by means of a key- actuated lock may be incorporated into the machine describe above with reference to Figures 1 to 4. The manner in whic this facility may be incorporated into the machine, together with a possible construction of the mechanism of the lock 14, is illustrated in Figure 5. There is also illustrated in Figure 5 an alternative form of hinging of the lid; instead of using cranked arms 13 to provide the offset hinging of Figure 3, the lid 12 in this case is hinged directly to the foremost edge of the platform 3 by an elongate hinge 17.Referring to Figure 5, the catch 15 is arranged to enter slots 18 of a plate 19 of the lock 14, when the lid 12 is closed. A lock-slide 20 is biased by a spring 21 into engagement with the catch '15 in the slots 18 for holding the lid 12 down. An electromagnetic solenoid 22 is coupled to the slide 20 and is energized transitorily from the electron circuits of the machine, indicated schematically as block 23 in Figure 5, whenever the till is to be opened in response to relevant operation of the keys 9. Energization of the solenoid 22 withdraws the slide 20 so as to release the catch 15 and thereby allow the lid 12 to open.The catch 15 can be released alternatively by actuatio of a cylinder lock 24 mounted on the platform 3 of the machine. In this respect insertion and rotation of the appropriate key 25 in the lock 24, engages a lug 26 with a pin 27 on the slide 20 to withdraw the slide 20 and release the catch 15. An interlock is provided to ensure that the lock- slide 20 can only be withdrawn while the lid 12 is closed. In this respect a cranked ar 28 is biased by a spring 29 into the path of a shoulder 30 on the slide 20, so as to prevent withdrawal of the slide 20 to an extent sufficient to release the catch 15. When the lid 12 is closed, an arm 31 moves to displace the arm 28 against the action of the spring 29 and clear the path of the shoulder 30 from obstruction. Thus it is only when the lid 12 is closed to displace the arm 28- that the lock 14 can be released; this reduces the possibility of the lock action being interfered with for the purpose of subsequent dishonest withdrawal of money from the till.An electrical micro-switch 32 is provided to respond to withdrawal of the lock-slide 20 and signal this fact to the electronic circuits 23 of the machine. The electronic circuits 23 are unresponsive to actuation of the keys 9 during signalled withdrawal of the slide 20.Other forms of hinging of the till-compartment lid from those illustrated in the drawings may be used. In particular the lid may be hinged to move forwardly of the machine; the lid and the set of keys may in this respect be inclined more steeply downwardly from the platform 3 and be pivoted to move forwardly and downwardly to open the till. However, the lid may be arranged for displacement otherwise than by hinging, and in this respect may be arranged to slide; in particular the lid may be arranged to slide up and under, or up and over, the platform 3 for enabling access to the till-compartment 10. Furthermore the location of the catch may be different from that described above. In particular the latching face may be provided on an extension of the lid to the rear of the hinge, and in these circumstances the catch, together with the release solenoid, may be housed more within the body of the machine so as to be less accessible to interference. Q O ι< t - (~ - | CLAIMS1. A cash register having a set of keys for entering data and instructions into the register and a till that is opened in response to predetermined key-operation, characterised in that the till is a compartment that is closed by a displaceable member, and that the said member is displaced in response to said predetermined key-operation to enable access to said compartment.2. A cash register according to Claim 1, further characterised in that the keys are carried by the said member.3. A cash register according to Claim 2, further characterised in that the said compartment is provided at the front of the register-body, and that the said member slopes down¬ wardly towards the front of the body when it closes the compartment such that the set of keys is then inclined forwardly of the register.4. A cash register according to Claim 3, further characterised in that the said member is a lid to the compartment, and.that the set of keys is incorporated into the upper surface of the lid.5. A cash register according to Claim 1, 2, 3 or 4 further characterised in that the said member is a hinged lid.6. A cash register according to Claim 1, 2, 3 or 4 further characterised in that the said member is urged to move from the position in which it closes the said compartment, and that a releasable lock-mechanism which is for holding the said member in the said position is released in respons to said predetermined key-operation so as to open the till. A cash register according to Claim 1, 2, 3 or 4 further characterised in that a releasable mechanism is operative to hold said member in the position in which it closes the said compartment, and that an interlock is operative to inhibit release of the said mechanism unless the said member occupies that said position. | CHUBB ELECTRONICS LTD; VALLANCE L | VALLANCE L |
WO-1979000515-A1 | 1,979,000,515 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | A61K31 | A61K31 | A61K31, A61K38, A61K39, A61K47, C12N11 | A61K 39/44, A61K 47/48K4, A61K 47/48R2T, C12N 11/08 | METHOD OF EFFECTING CELLULAR UPTAKE OF MOLECULES | A method of effecting cellular uptake of molecules which are either excluded from cells or poorly transported into cells is disclosed wherein such molecules are covalently bonded to a cationic polymer which serves as a transport carrier to transport the molecules into cells. | DESCRIPTIONMETHOD OF EFFECTING CELLULAR UPTAKE OF MOLECULESTechnical Field This invention is in the fields of cell biology and cellular and molecular pharmacology.Background ArtIt is known that many molecules of a wide variety are not transported, or are poorly transported, into living cells. Macromolecules, for example, such as proteins, nucleic acids, and polysaccharides, are not suited for diffusion or active transport through cell membranes simply because of their size. In order to allow such macromolecules to pass into cells, cell membranes form small vesicles which migrate from the periphery to the interior of the cell, a process known as pinocytosis. This form of transport is generally less efficient, however, than the diffusion or active transport of smaller molecules, and thus, the cellular uptake of macromolecules is limited.The most common reason why many small molecules are excluded or poorly transported into cells is their ionic charge. The mere presence of either negatively or positively charged groups severely limits cellular uptake of small molecules, such as nucleotides, nucleotide analogues, cofactors and a number of drugs. While the two reasons discussed above are the main factors which limit cellular uptake of molecules, there are undoubtedly other reasons as well. Be¬ cause of these limitations in the cellular uptake of certain molecules, there has been a large amount of research directed to overcoming or obviating inadequate cellular transport of such molecules.One method previously suggested by Ryser involves the use of cationic polymers, i.e., macromolecules which bear a sequence of positive charges. In this method, it was found that cellular uptake of some molecules could be improved by the simple presence in the experimental medium of such cationic poly¬ mers, especially homopolymers of positively charged amino acids such as poly-L-lysines, poly-D-lysines and poly-L-ornithines. See Ryser, H. J.-P., Uptake of Protein by Mammalian Cells: An Underdeveloped Area , Science, 159, 390-6 (1968); and Ryser, H. J.-P., Transport of Macromolecules, Especially Proteins Into Mammalian Cells , Proc. Fourth Internat.Congress on Pharmacology (1970); and, Ryser, H. J.-P., Poly(amino acids) as enhancers in the cellular uptake of macromolecules, in 'Peptides, Polypeptides and Proteins' , Proceedings of the Rehovot Symposium on Polyamino Acids, Polypeptides and Proteins and their Biological Implications, May 1974, E. R. Blout, F. A. Bovey, M. Goodman and N. Lotan, Eds, John Wiley and Sons, Inc., New York, pp 617-628 (1974). It has also been shown that protoplasts prepared from mesophyll of Nicotiana tabacum can be infected by adding purified tobacco mosaic virus particles to a protoplast suspension in the presence of poly-L- ornithine whereas infection does not occur if poly-L- ornithine is not present. See Takebe, I. and Otsuki, Y., Infection of Tobacco Mesophyll Protoplasts byTobacco Mosaic Virus, Proc. N.A.S., 64, pp 843-8 (1969).OMPIA, The presence of strongly positively charged proteins, such as histones, also increased cellular uptake of albumin. See Ryser, H. J.-P. and Hancock, R. , Science, 150, pp 501-3 (1965). While this prior technique did improve cellular uptake of some macromolecules, it suffered from a number of deficiencies. For example, only minimal enhancement was found for some proteins, e.g., horse¬ radish peroxidase. Also, the cationic polymers form, at most, reversible complexes with the molecule to be transported and may interact at random with other molecules in the medium which means that the en¬ hancement lacks specificity and rέproducibility. Further, it was found that enhancement required using cationic polymers of relatively high molecular weight, and that, for example, cationic polymers with molecu¬ lar weights around 6000 were practically ineffective. See Ryser, H. J.-P., A Membrane Effect of Basic Polymers Dependent on Molecular Size , Nature, Lond. , 215, pp 934-6 (1967) . In summary, this technique provided some enhancement of cellular uptake for some macromolecules, but even in these cases enhance¬ ment was only modest, non-selective, variable and required polymers of large molecular size. Other researchers have covalently linked enzymes to polymers for purposes other than cellular trans¬ port. Goldstein et al., in U. S. Patent 4,013,511, for example, describe a method for insolubilizing or immobilizing enzymes by covalently bonding the enzymes to anionic or cationic resins. In this method, polymeric resins are formed by reacting ethylene- maleic anhydride copolymer (EMA) and a suitable diamine, such as hydrazine, p,p'-diaminodiphenyl methane or a primary aliphatic diamine such as 2,6-diamino- hexane. Such resins are anionic, but can be made cationic by reacting them with N,N-dimeth l-l,3- propanedia ine (DMPA) in the presence of an activat¬ ing agent, such as dicylohexylcarbodiimide (DCC) . Both the anionic and cationic polymeric resins can be covalently coupled to biologically active proteins such as enzymes.Goldstein et al. ('511) point out that immo¬ bilized enzyme derivatives serve as specific easily removable catalysts that can be used repeatedly in columns and in batch reactors. The invention de¬ scribed in U. S. 4,013,511 appears to be a continua¬ tion or earlier work by the same researchers which •was generally directed to insolubilizing enzymes by reacting them with polymers. See, for example, U. S. Patents 3,627,640; 3,650,900; 3,650,901; and3,706,633. All of these patents contain a description of various techniques which can be used to bond enzymes to polymers. Another patent, namely U. S. Patent 3,374,112, issued to Katchalski et al. , discloses the covalent bonding of enzymes to a water insoluble copolymer of L-leucine and p-aminophenyl- DL-alanine, for a similar purpose.It has also been reported that cationized ferritin can be formed by carbodii ide coupling of horse spleen ferritin to a diamine, namely, N,N- dimethyl-1,3-propanediamine. Cationized ferritin was proposed by these researchers as a tracer mole¬ cule for the detection of negatively charged groups on the surface of red blood cells. See Danon, D., Goldstein, L., Marikovsky, Y. and Skutelsky, E., Use of Cationized Ferritin as a Label of Negative Charges on Cell Surfaces, J. Ultrastructure Res., 38, pp 500-512 (1972); and Grinnel, F., Tobleman, M. Q. and Hackenbrock, C. R., The Distribution and Mobility of Anionic Sites on the Surfaces of BabyHamster Kidney Cells, J. Cell Biol., 66, 470 (1975). - 6 - have molecular weights of 5000-500,000 and free car- boxyl, amino or cycloimidocarbonate groups so that cytotoxic drugs containing amino or carboxyl groups can be covalently bonded thereto. Poly(amino acids), including polylysine, polyaspartic acid, polyarginine, etc., are described as potentially useful polymer carriers for this purpose.Similar attempts to increase drug selectivity by attaching the drug to antibodies are described in British Patent Specification 1,446,536 and South African patent application 76-2966. These patents disclose techniques for covalently bonding anti-cancer drugs to antibodies or antigen-binding fragments of antibodies specific for tumor antigens. Still further work involving covalently bond¬ ing a potential' anti-cancer drug to a polymeric carrier is described in AACR Abstract 454, Proceedings of AACR and ASCO, p 114 (1978) . In this work, 6-arnino*- nicotinamide was covalently linked to poly-L-lysine to lower the central nervous toxicity of. this drug.Disclosure of the InventionThis invention relates to a method for effect¬ ing or enhancing cellular uptake of molecules which are either excluded from or are taken up poorly by cells. The method is based upon the discovery that cellular uptake of such molecules can be increased if a conjugate of these molecules is formed by co¬ valently bonding them to a cationic polymer. For rea- sons not entirely understood, the cationic polymer appears to serve as a transport carrier for the ex¬ cluded molecule, and the conjugated molecule is transported through cell membranes in a much more effective manner than the unconjugated molecule. - 5 - A low density lipoprotein was cationized using the Danon .et al. technique and shown to accumulate in human fibroblasts. Since low density lipopro¬ tein carries cholesterol into the cells, it was noted that the cationized form of the low density lipoprotein provided a model system for the study of the pathologic consequences at the cellular level of massive deposition of cholesteryl ester. See Basu, S. K. , Anderson, G. W. , Goldstein, J. L. , and Brown, M. S., Metabolism of Cationized Lipoproteins by Human Fibroblasts , J. Cell Biology, 74, pp 119- 135 (1977) . This method of cationizing a protein has several weaknesses as a method to enhance cellu¬ lar uptake. For example, the diamine used is not digested by intracellular proteolytic enzymes and thus may accumulate in cells and cause cytotoxic effects. Further, adequate cationization requires attachment of a large number of diamine molecules to carboxyl groups of proteins. Thus, it has been reported that 70% of all of the carboxyl groups of LDL have been modified by this procedure. Such drastic modification would be expected to destroy the bio¬ logical activity of most functional proteins. Addi¬ tionally, the diamine used is not suitable as a carrier to enhance the cell penetration of small molecules.Recent work has been directed to covalently bonding drugs, including anti-cancer drugs, to immuno- globulins or immunoglobulin derivatives for the purpose of directing drugs to cells bearing specific antigens. U. S. 4,046,722, for example, describes an immunoglo¬ bulin specific for antigens on the surface of cells to be killed, to which 1-10 polymer carrier mole¬ cules are covalently bonded, the polymer carriers having themselves about 5-500 molecules of a cytotoxic drug covalently bonded to them. These polymer carriers Thus, the method of enhancing the cellular uptake of molecules comprises first covalently bonding them to a cationic polymer and subsequently administering the resulting conjugate to cells. This method can be used to enhance cellular up¬ take of macromolecules which normally are not effec¬ tively transported into cells. These macromolecules include proteins, such as enzymes, growth factors or other regulatory proteins, peptides, polypeptide hormones, lectins, antigens, antibodies or fragments thereof; informational macromolecules such as DNA and RNA; εubcellular organelles and supermolecular parti¬ cles such as chromosomes or components thereof; polysaccharides; etc. Importantly, the method also has application to cellular uptake of excluded small molecules including nucleotides, nucleotide analogues, cofactors (e.g., cyanocobalamin) , and drugs in general. As used herein, the term drug is used in a broad sense to mean any substance used to treat a disease or to modify a condition in living organisms, particularly including human beings and other mammals.The degree of enhancement of cellular uptake has been found to be surprising and dramatic. For some proteins, for example, the formation of a con¬ jugate according to this invention has been found to increase cellular uptake by factors ranging up to several hundred-fold.In addition to the dramatic enhancement of cellular uptake, this method has other significant advantages. For example, this method may require the modification of only one carboxyl group located on the surface of a functional protein. Such minor modification is not likely to destroy biological function. Thus, for example, a biologically active enzyme can be conjugated and transported into cells without losing its enzymatic activity. Furthermore, this method employs relatively small amounts of cationic polymer and is not limited to cationic polymers of large molecular size.Perhaps even more important is the fact that this method is also effective with small molecules which are excluded or poorly transported into cells as long as those molecules can be covalently bonded to a cationic polymer. Thus, the method is capable of providing dramatically increased cellular transport of molecules such.as drugs, co-factors, nucleotides, nucleotide analogues, etc.In many cases, a very important advantage can be gained by using selected cationic polymers, such as poly-L-lysine and poly-L-arginine, which are ex¬ cellent substrates for physiologic proteolytic enzymes present in mammalian cells. This means that these cationic polymers, after having served as a transport carrier, can be digested or otherwise broken down inside the cells into normal physiologic by-products.Brief Description of DrawingsFIG. 1 contains several plots of data obtained from consecutive elution fractions exiting from a chromatographic column loaded with a reaction mix¬ ture of horseradish peroxidase (HRP) , poly-L-lysine (PLL) and carbodiimide reagent which plots represent the HRP content and HRP enzymatic activity of consecu- tive fractions as well as their ability to enter cells; FIG. 2 is a plot illustrating the uptake of labeled methotrexate (MTX) and labeled methotrexate- poly-L-lysine conjugate (MTX-PLL) by transport- proficient and transport-deficient cells; FIG. '3 is a plot illustrating the growth inhibi¬ tory effects of methotrexate (MTX) and methotrexate- poly-L-lysine conjugate (MTX-PLL) administered to cultures of transport-proficient and transport- deficient cells;FIG. 4 is a plot illustrating the inhibitory effect of free methotrexate (MTX) , methotrexate- poly-L-lysine conjugate (MTX-PLL) and partially digested conjugate on dihydrofolate reductase ac¬ tivity, in vitro;FIG. 5 illustrates elution profiles of intra- cellular degradation products of 3H-MTX-PLL and 3H-MTX-PDL conjugates;FIGS. 6 and 7 are plots of data illustrating the effect of MTX and MTX-PLL conjugate on the sur¬ vival of mice bearing an MTX-resistant and an MTX- sensitive Ivmphosarcoma, respectively;FIG. 8 is a plot illustrating the growth of L 929 fibroblasts following their brief exposure to free 6-mercaptophosphoribosylpurine (6-MPRP) , a mixture of free 6-MPRP and free poly-L-lysine (PLL) , conju- gated 6-MPRP-PLL, and trypsinized 6-MPRP-PLL conju¬ gate;FIG. 9 is a plot illustrating the cellular uptake of labeled poly-L-lysine of varying molecular weight, corrected to equimolar concentrations; FIG. 10 is a plot of data illustrating the level of mtracellular breakdown products of 125I-PLL in¬ gested by Sarcoma S-180 cell monolayers which are present in the cells and in the cell medium;FIG. 11 is a plot illustrating the in vitro effect of trypsin and heparin addition upon aggregates of human serum albumin (HSA) and poly-L-lysine (PLL) and aggregates of HSA and poly-D-lysine (PDL) ; and,FIG. 12 is a plot illustrating the in vitro effect of trypsin upon aggregates of HSA and each of poly-L- lysine (PLL) , poly-L-ornithine (PLO) and poly-L- homoarginine(PLHA) . Best Mode of Carrying Out The Invention There is a wide variety of molecules which can be covalently bonded to cationic polymers according to thi invention to increase cellular uptake thereof. Include are certain marcromolecules such as peptides, including oligopeptides, polypeptides and glycopeptides; proteins, including glycoproteins and lipoproteins; polysaccharid including mucopolysaccharides; lipids, including glyco- lipids; nucleic acids, including RNA and DNA, either in soluble form or as part of supramolecular structures or organelles. Many small molecules are also suitable, including drugs, cofactors (e.g., cyanocobalamin) , nucleotide analogues, etc., which are either excluded or only poorly transported into cells. In fact, it is believed that suitable conjugates can be formed for any molecule excluded from cells or only poorly trans¬ ported into cells and which can be covalently bound to a cationic polymer. It is recognized, of course, that every molecule is probably transported into cells in some exceedingly small quantity and the term excluded is used herein in a functional sense rather than an absolute quantitative sense.It is particularly noteworthy that biologically active enzymes can be covelently bonded to cationic polymers without losing their biological activity. This means that the intracellular content of biologically active enzymes can be increased by increasing thier membrane transport, as illustrated by Examples 6-10, below. Molecules which are excluded from cells are usually those normally excluded because of thier charge pattern, size, or for other physico-chemical reasons. This method also applies, however, to molecules which are not normally excluded but become excluded because ofO * r -■ » ■ -»_rτf-11- mutations. Such mutations may lead either to the loss of a transport mechanism e.g., certain forms of drug resistance, as illustrated by Examples 14, 15, 23, 25, 27 and 28 below, or to the loss or impairment of a 5 receptor site on cells (e.g., certain forms of familial- hypercholesterolemia) ot to the loss or impairment of a recognition marker on the molecules (e.g., certain ucopolysaccharidoses) .As used herein, the term cationic polymer means 0 a polymer or macromolecule containing positively charged groups sufficient to enhance cellular uptake of molecules covalently bound to it. Such polymers include homo- polymers and copolymers (random and block) ; linear, branches and crosslinked polymers; and synthetic and 5 naturally occurring polymers.Typically, although not exclusively, the positively charged groups are primary, secondary or tertiary amines which ionize at or around neutral pH. Such amine groups might be present as: amino groups in side chains as in 0 poly(amino acids); amino groups included in a polymer backbone as in poly(amines) ; or amino substitutents added to an uncharged polymer, such as result in dextran substituted with diethylaminoethyl groups. Polymers containing other positively charged groups, 5 such as quaternary amines, the sulfur group in S- methyl methionine, etc., would also be suitable.The preferred cationic polymers are cationic poly- (amino acids) , such as poly-L-lysine, which can be repre¬ sented by the structural formulao HN- wherein n is an integer of 5 to 2000. A detailed des¬ cription of poly(amino acids) is given in the follow¬ ing literature reference, the teachings of which are hereby incorporated by reference: Fasraan, G. D.„ Poly-ά^-amino Acids , Marcel Dekker, Inc., New York (1967) .Specific poly(amino acids) which are suitable include, but are not limited to, poly-L-lysine, poly-L-ornithine, poly-L-arginine, poly-L-homoarginine, poly-L-diaminobutyric acid, poly-L-histidine, the D- optical isomers thereof and copolymers thereof. Co- polymers may include noncationic amino acid residues. Cationic pol (amino acids) are preferred because of the outstanding enhancement in cellular uptake which they provide. Additionally, it is often de¬ sirable to employ cationic polymers which are digested by proteolytic enzymes present in mammalian cells, and some pol (amino acids), such as, for example, poly-L- lysine and poly-L-arginine, provide this capability. There are other classes of cationic polymers which are suitable in addition to poly(amino acids). These include polymers with neutral or anionic backones to which cationic groups have been bonded, as in the case of substituted polysaccharides (e.g., diethylaminoethyl dextran) , substituted cellulose, substituted copolymers of ethylene and aleic anhydride, substituted lactic or glycolic acid polymers, etc. Polyamines, such as for instance, poly(vinyl a ine) , or other cationic synthetic polymers, are also suitable. See Examples 9 and 10 below.Certain positively charged, naturally occurring macromolecules also serve as suitable cationic polymers. Specific examples include protamines and histones, such as. those found to increase cellular uptake of albumin by their simple presence. See Ryser, H. J.-P. and Hancock, R. , Science, 150, pp 501-3 (1965). OtherOΛ'PI' endogenous cationic macromolecules, especially peptides, endowed either with high rates of cellular transport or with special carrier properties might be isolated, purified and used as a carrier or vector for a ole- cule or macromolecule to be transported, as illustrated by Examples 11 and 12 below.In general, multiple positive charges present on a polymer or macromolecule will enhance cellular uptake of that molecule. In most cases, such multiple posi- tive charges will give the molecule a net positive charge. In other cases, however, the multiple charges may form an adequate sequence in the primary structure, or both, to cause enhanced cellular uptake, even though the molecule does not have an overall net positive charge. For example, a molecule containing a limited number of positive charges at various intervals in its primary structure may fold in a manner such that a cluster of positive charges will be positioned in the same spatial area of its tertiary structure. Alterna- tively, a copolymer of poly(amino acid) with a neutral or negative net charge may contain a functionally im¬ portant cluster of positive charges. Therefore, when used herein, the term cationic polymer refers not only to a macromolecule which has an overall positive net charge, but also includes macromolecules which contain sequential portions or spatial arrangements of positive charges sufficient to confer on them the transport properties of cationic polymers having a positive net charge thereon. Conjugation can be achieved by well-known chemical reactions. For example, carbodiimide coupling can be used to couple a carboxyl or phosphate group on the molecule to be conjugated with amino groups of a cationic polymer. Such reactions are described in the following__p PI_- i articles, the teachings of which are hereby incorpo¬ rated by reference: Halloran, M. J. and Parker, C. W. , The Preparation of Nucleotide-Protein Conjugates: Carondiimides as Coupling Agents , J. Immunology, 96, 5 373 (1966); Carraway, K. L. and Koshland, Jr., D. E., Modification of Proteins by Carbodiimide Reaction , Methods in Enzymology, Vol. 25B, p 616 (1972) ; Sheehan, J.C. and Hess, G. P., New Method of Forming Peptide Bonds , J. Am. Chem. Soc. , 77, 1067 (1955); and Kurzer,10 F. and Douraghizadeh, K., Advances in the Chemistry of Carbodiimide , Chem. Rev., 67, 107 (1967) .A typical conjugation reaction between a protein (P) and a poly(amino acid) (PAA) and employing a carbodiimide (CDI) catalyst can be illustrated as15 follows:PROTEIN-PAAPROTEIN PAA CONJUGATESuch a conjugation is further illustrated by Examples 1 and 2 below._OMP■ '~wiP Similarly, a typical carbodiimide conjugation reaction between a nucleotide formed from a purine or pyrimidine base and a poly(amino acid) can be illustrated as follows:NUCLEOTIDE-PAANUCLEOTIDE PAA CONJUGATESuch a conjugation is further illustrated by Example 15 below.Conjugation can also be achieved for certain mole- cules by glutaraldehyde coupling between amino groups on conjugate molecules with amino groups on cationic polymers. Glutaraldehyde coupling is described in the following literature references, the teaching of which are also incorporated by reference: Avrameas, S. and Ternynek, T., Peroxidase Labelled Antibody and Fab Conjugates with Enhanced Intracellular Penetration , Immunochemistry, 8, 1175-1179 (1971); Gonatas, N. K., Ki , S. U., Stieber, A. and Avrameas, S., Horseradish Peroxidase - Lectin Conjugates , J. Cell Biol. , 73, 1-13 (1977) .Depending upon the individual molecule to be con- 5 jugated, other modes of conjugation can be employed. For instance, reductive periodation can be useful to conjugate daunomycin or other carbohydrate-containing molecules to any amino group-containing carrier. Such a reaction is described in the following literature10 reference, the teaching of which are incorporated by reference: Hurwitz, E., Levy, R. , Maron, R. , Wilchek, M., Arnon, R., and Sela, M., Cancer Research, 35, 1175, (1975).Conjugation can also be achieved by using an inter-I5 mediate molecule to link the drug to the carrier.Examples of such intermediate molecules, which might also be called spacer molecules, are oligopeptides, succinyl anhydride, and maleic anhydride. Conjugations which incorporate such spacer molecules' may require a20 two-step reaction, in which the spacer molecule is first linked to the drug and the spacer-drug conjugate is then linked to the carrier. Thus, the term covalently linked, as used herein, encompassed the use of such spacer molecules to bind the molecules to25 be transported to a cationic polymeric carrier.Those skilled in the art will recognize, or be able to determine using no more than routine experi¬ mentation, other suitable conjugation mechanisms to covalently bond a specific molecule to be transported30 into cells to a specific cationic polymer chosen as a transport carrier.The rate of cellular uptake of conjugates prepared according to this invention can be varied by varying the molecular weight of the cationic polymer, such as poly- L-lysine, employed to form the conjugate. Since it has been clearly demonstrated that the cellular uptake of labeled poly-L-lysine increase with its molecular weight (see Example 31 and FIG. 9), it can be expected that the same correlation will hold for other cationic polymers. When a drug is conjugated to poly-L-lysine of difference molecular sizes, and provided the ratio of drug to unit weight of poly-L-lysine is constant, it can be seen that the level of cellular uptake of the conjugated drug will be determined by the molecular weight of the poly-L-lysine carrier. Hence the rate of cellular uptake of a conjugated drug can be predetermined by the molecular size of the homo¬ logous polymeric carrier. The rate of drug uptake, of course, also depends upon the number of drug mole¬ cules bound per unit weight of polymeric carrier.Although the rate of cellular uptake increases with increasing molecular weight of cationic polymers such as poly-L-lysine, it does not follow that a comparably increased biological effect can always be seen. For example, the data obtained in Example 22 do not evidence an increasing biological effect for increasing molecular weight poly-L-lysine in MTX-PLL conjugates administered to CHO PRO-**** MTX-*-***-***-* 5-3 cells. This indicates that other factors, such as intracellular degradation, affect biological activity.The rate and extent of intracellular release of molecules which-are covalently bonded to cationic polymers to form conjugates can also be controlled. This can be done by choosing polycationic polymeric carriers which differ in their susceptibility to intra¬ cellular digestion. It is known, for instance, that poly-L-lysine is very susceptible to trypsin and other proteolytic enzymes, while poly-D-lysine is not. This is demonstrated by the data of Examples 17 and 19 below. While methotrexate-poly-L-lysine (MTX-PLL) and metho- trexate-poly-D-lysine (MTX-PDL) conjugate enter cells at comparable rates, as shown by Example 16, they have different biological effects: MTX-PLL strongly inhibit the growth of MTX-resistant cells; MTX-PDL has no such effect.Carriers with intermediate susceptibility to proteolysis can be devised by using copolymers of amino acids or homopolymers of unnatural amino acids. An example of the latter is given in Example 36 and FIG. 12, and these show that poly-L-homoarginine has a susceptibility to trypsin intermediate between that of poly-L-lysine and poly-L-ornithine. Another method of controlling the intracellular release of molecules which are covalently bonded to cationic polymers is to modify the bonding procedure. One important modification is the introduction of a spacer molecule which is bonded on one side to the drug and on the other side to the carrier, as described above. When such a spacer molecule is an oligopeptide, for example, and as such susceptible to proteolytic digestion, it can be selectively digested inside the cell and the drug can be released even when the cationic carrier is not itself digestible.Those skilled in the art will be able to take ad¬ vantage of adjusting the level of cellular uptake as well as controlling the degree of intracellular digest¬ ibility and/or release by the above-described techniques by employing routine experimentation to determine the exact conjugate for their purpose.It should be recognized that a macromolecule to be covalently bonded to a cationic polymeric trans¬ port carrier could itself be bonded to or complexedOΛ * W1 -21- Methotrexate is one example of a drug to which cells can be or can become resistant because of deficiencies in cellular uptake, but there are others. For example, 5-fluorouracil, fluorodeoxyuridine, cytosine, arabino- 5 side, vinblastin, vincristin, daunorubicin, doxorubicin, actinomycin, and bleomycin all suffer from similar limitations, and conjugations of these to cationic polymers would also increase cellular uptake of these respective drugs into otherwise drug-resistant cells. 0 Another chemotherapeutic application of this invention arises in regard to those drugs to which cells become resistant due to inadequate intracellular activation of the drug. A prototype of a cancer drug to which tumor cells have become resistant for lack of 5 drug activation is 6-mercaptopurine (6-MP), a purine analogue. A common cause of tumor cell resistance to 6-MP is the loss of the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT) which activates 6-MP into its corresponding nucleotide. Generally 0 speaking, a nucleotide is the ribosyl- or deoxyribosyl phosphate of a purine or pyrimidine base, and more specifically in this case, a nucleotide analogue is the ribosyl- or deoxribosylphosphate of a purine or pyrimi¬ dine base analogue. The HGPRT activation of 6-MP, to 5 the nucleotide analogue, 6-mercaptophosphoribosylpurine(6-MPRP) , requires the attachment of 5-phosρho-D-ribose derived from 5-phospho-, --D-ribose pyrophosphate (PRPP) and can be illustrated as follows: -22-When the HGPRT enzyme is absent, 6-MP is without effect since the lethal form of the durg, i.e., the nucleotide analogue 6-mercaptophosphoribosyl purine (6-MPRP) , is not synthesized following cellular uptake. 5 This resistance could be overcome if 6-mercapto- phosphoribosyl purine itself could be introduced into the cell. Although this compound is commercially available, it has heretofore not been used therapeuti- cally in cancer treatment because it is not adequately 0 transported into living cells. Modification of this drug to covalently bond it to a cationic polymer would dramatically increase its ability to cross the cell membrane. An example of a carbodiimide conjugation to covalently bond 6-MPRP to a pol (amino acid) through 5 a terminal phosphate groups of the nucleotide analogue is given in Example 29 below and can be illustrated as follows:6-MPRP 6-MPRP-PAAPAA • CONJUGATEA similar conjugation could be made using the terminal phosphate of 6-mercaptophosphoriboxyl purine triphos- phate (6-MPRPPP) . Similar conjugations could, of course, be made to cationic polymers other than poly (amino acids) .The same enzyme, HGPRT, also activates another-BUROM ι A *μ WIP -19- with one or more different small molecules, or could itself be carrying a Gore of small molecules. LDL and ferritin, for example, are examples of macromole¬ cules which have such special transport properties. Enhancement of cellular uptake of molecules normally excluded from cells or only poorly transported into cells can be utilized in many applications.One area of application is the range of cancer treatments known generally as cancer chemotherapy, especially those involving drug-resistant cancers. Several important such chemotherapeutic applications are now described.One significant reason for resistance to a chemo¬ therapeutic drug is a deficiency in cellular uptake of that drug. A prototype drug known to encounter the development of such resistance is methotrexate. Metho¬ trexate, a widely used cancer drug, is an analogue of folic acid and blocks an important step in .the synthesis of tetrahydrofolic acid which itself is a critical source of 1-carbon compounds utilized in the synthesis of thymidylate. Thymidylate is a building block that is specific, and therefore especially critical, for DNA synthesis.A conjugate formed between methotrexate and a cationic polymer, particularly a poly(amino acid) such as poly-L-lysine, would enhance cellular uptake of methotrexate and carry the drug into methotrexate- resistant tumor cells. A carbodiimide coupling reaction for forming a suitable conjugate between methotrexate and a poly(amino. acid) can be illustrated as follows: -20-METHOTREXATE. PAAAlthough the above reaction is shown for purposes of illustration as involving one molecule of methotrexate conjugated through one of its carboxyl groups to one amino group of the carrier, in practice a number of molecules of methotrexate could be conjugated to a number of amino groups belonging to one molecule of cationic polymer, as illustrated by Example 13 below. Also, both carboxyl groups of each methotrexate molecule might be conjugated. Additionally, it should be understood that other reactions could also be used to covalently bond methotrexate to a poly(amino acid) or to other cationic polymers, and that such reactions could include the incorporation of a spacer molecule as described above. cancer drug called thioguanine. A similar thioguanine-PLL conjugate could be formed to overcome resistance to this drug due to lack of the enzyme HGPRT.There are also pyrimidine analogues which undergo activation to nucleotide analogues. These include5-fluorouracel, 5-fluorouracil deoxyribose, 5-trifluor- omethyl deoxyuridine, triacetyl-6-azauridine, cytosine arabinoside and adenosine arabinoside. The drug cytosine arabinoside, for instance, is an analogue of cytosine riboside, which is a physiological nucleoside. A nucleoside is a ribosylated or deoxyribosylated purine or pyrimidine base. Cytosine arabinoside is a nucleoside inwhich the normal pentose, i.e., ribose, has been replaced by an abnormal pentose, i.e., arabinose. The activation of cytosine arabinoside to the corresponding nucleotide requires the attach¬ ment of a phosphate, whichis provided by adenosine triphosphate (ATP) , the latter being converted to adenosine diphosphate (ADP) . This reaction is catalyzed by the enzyme deoxycytidine kinase (DOCK) , according to the reaction: There are known cases of drug resistance due to the loss of the enzyme deoxycytidine kinase. In such cases, cytosine arabinoside is without effect, since the lethal for of the drug, i.e., the cytosine arabinosylphosphate nucleotide, is not synthesized following cellular uptake of the drug. The activated form of this particular drug, and other similar drugs, is commercially avail- able but has heretofore been therapeutically inefficient because it is not transported into living cells. How¬ ever, cationic polymers such as poly-L-lysine can be coupled to the terminal phosphate of the cytosine arabinosylphosphate nuceotide, or other nucelotide analogues to enhance their cellular uptake.Another form of drug resistance encountered in cancer chemotherapy is due to increased breakdown of a drug within the cell. One illustrative pathway of such inactivation is deamination of a pyrimidine base. it is known, for example, that cytosine arabinoside is more susceptible to deamination than its corres¬ ponding nucleotide. Thus, the direct introduction of a conjugate form of the nucelotide analogue cytosine arabinosyl phosphate would have the added advantage of being less susceptible to that form of inactivation and would thus be capable of overcoming a drug resistance that is due to increased drug destruction.In addition to its utility in the cancer chemo- therapeutic techniques described above, this invention also has significant application in aspects of cancer chemotherapy not necessarily related to drug resistance. For example, certain nucleotide analogues, which were found to be biochemically very effective in cell free systems, have never been developed as potential drugs because of their poor transport into cells. One such nucleotide analogue which is a very powerful inhibitor of DNA synthesis in cell free systems is dideoxyadeno- sine triphosphate. In cell free systems, this nucleo¬ tide analogue is incorporated into DNA, and once in- corporated, blocks further elongation of the DNA molecule because of lack of the chemical group (3'- hydroxyl) required for polymerization. This compound cannot be used in the form of its precursor because cells are unable to synthesize a nucleotide of dideoxy- adenosine. The nucleotide itself is not effective in therapy because it is not adequately taken up by cells. However, if this nucleotide were covalently bonded to a cationic polymer, such as poly-L-lysine, it could be transported into cells and function therein to kill tumor cells.Still another application for this invention in cancer chemotherapy relates to a recently developed treatment for bone and muscle tumors wherein lethal doses of a drug, such as methotrexate, are administered, followed by administerion of large doses of folinic acid. This is known as rescue therapy because the doses of methotrexate administered would kill the patient by totally depleting the stores of folinic acid if the patient were not saved after a suitable interval by administration of large doses of folinic acid. Folinic acid is taken up readily by normal cells and less so by tumor cells, and thus the ratio of tumor to normal cells killed is improved. Such im- provement could be especially significant in drug resistant tumors with deficiencies in methotrexate - transport, becuase such deficiencies often extend to the transport of folinic acid.Comparable rescue procedures have not yet been worked out for drugs other than methotrexate, for instance, purine or pyrimidine analogues. In theory, they could be used in the course of therapy with 6-MP or any of the other purine or pyrimidine analogues men¬ tioned previously, since the agents of rescue, i.e., normal nucleotides, are known and commercially available. The reason nucelotides have not been used for that pur¬ pose is, once again, that such nucleotides do not enter cells. If these nucelotides could be modified to pene¬ trate into cells, they would immediately become avail- able as rescue agents. The principle of this rescue treatment is to provide cells with the product of the enzymatic reaction that is blocked by the drug.The rationale of this rescue procedure is that fast growing normal cells which are hit by the drug may re- spond more favorably than tumor cells to the antitode of the drug, i.e., the normal nucleotides. Empirical trials have shown that this premise is fulfilled for the folinic aciά-methotrexate combination. Thus, there is a good reason to assume that this premise would hold for the combination of purine or pyrimidine analogues and the corresponding normal nucleotide conjugates.In addition to cancer chemotherapeutic applications this invention can also be used in antimicrobial chemo¬ therapy. For example, adenosine arabinoside, a nucleo- side very similar to cytosine arabinoside, has been found to be very effective in the treatment of Herpes Encephalitis, a viral infection of the brain. To be effective, this drug must be activated in the cell to a full nucleotide, adenosine arabinosyl phosphate, which inhibits virus replication inside the cell. It is known that this drug has not been effective in all cases and it is probable that one reason for some of the failure has been drug resistance occurring either because this drug is taken up too slowly by infected cells, destroyed too rapidly inside the cells or not properly activated into fully effective nucleotides. Thus, the availabilit of a conjugate between adinosine arabinosyl nucleotide and poly-L-lysine or other cationic polymer would over¬ come such drug resistance. The invention is further illustrated by the fol¬ lowing specific examples.' U0M EXAMPLE 1.COVALENT BONDING (CONJUGATION) OF POLY-L-LYSINE TO HUMAN SERUM ALBUMINCrystalline human serum albumin (HSA) , poly-L- lysine (PLL) of average molecular weight of 6700, and l-ethyl-3-(3-dimethyl-aminopropyl)carbodiimide (EDC) were dissolved in equal amounts of 20 mg each in 0.8 ml water. This solution was incubated at 25° c for 3 hours with occasional shaking, and then loaded onto a Sephadex GlOO chromatographic column which had been previously' equilibrated with 0.01 M phosphate buffered saline (PBS), pH 7.0. After loading, the column was eluted with PBS and fractions containing protein coming out of the column at and around the void volume were collected, pooled, concentrated to a volume of 1.0 ml, and then diluted with water to a volume of 10.0 ml. In order to remove unreacted HSA, this low salt solution was passed through a DEAE-Sephadex column.A standard radioimmunoassay for HSA using anti- HSA-antibodies showed that the purified HSA-PLL conju¬ gate had lost more than 99% of its initial HSA antigeni- city, and thus that the preparation contained less than 1% unmodified HSA.Acrylamide disc gel electrophoresis at pH 4.5 showed the absence of unmodified HSA. The normal HSA band was replaced by a set of bands, including some faster moving bands, as would be expected for highly positively charged conjugates. The complexity of the electrophoretogram may suggest some poly-L-lysine in- duced crosslinkage between HSA molecules. EXAMPLE 2COVALENT BONDING (CONJUGATION) OFPOLY-L-LYSINE TO HORSERADISH PEROXIDASEThe procedures and reactants of Example 1 were used except that 20 mg of horseradish peroxidase (HRP) was substituted for HSA.Upon acrylamide disc gel electrophoresis at a pH of 4.5, unreacted HRP displayed two close and sharp bands of equal intensity. These two bands were no longer visible in similar electrophoresis of the reacted HRP. Instead, these two bands were replaced by faster moving bands as would be expected for highly positively charged conjugates. There were also several new slow moving bands, suggesting that poly-L-lysine had caused some crosslinkage between HRP molecules.The reaction solution was loaded onto a Sephadex GlOO chromatographic column which had been previously equilibrated with 0.01 M PBS, pH 7. Elution with PBS gave the profile presented by the solid curve in FIG. 1. This curve was obtained by measuring the HRP concen¬ tration of successive 2 ml column elution fractions using- the absorption of the heme group of HRP at 403 nm as a measure of concentration. As can be seen, there is a main peak corresponding to unreacted HRP and a shoulder located at the left of the main peak which shoulder corresponds to HRP-PLL conjugate. The fractions containing HRP-PLL conjugates, i.e., the equivalent of fractions 14 to 19 in FIG. 1, were pooled for use in the experiments described in Examples 6, 7 and 8. The enzymatic activity of the pooled HRP-PLL fractions was compared to that of unconjugated HRP us¬ ing an assay employing dianizidine as an electron acceptor. In this assay the rate of color development at 460nm (ΔA4.r60-nm/min) is used as an expression of enzymatic activity. It was found that the conjuga¬ tion decreased the enzymatic activity of HRP by about 50 to 60%. The enzymatic activity of each 2 ml fraction eluted from the column was determined using the same assay. The resulting data are shown as the dashed curve in FIG. 1.Each elution fraction was also tested for transport into L929 fibroblast cells as described in Example 6, below. The resulting data are plotted as the partially dotted - partially dashed line in FIG. 1. These results show that the HRP-PLL fractions which enter cells most effectively are the first fractions eluted from the Sephadex column, hence the fractions containing the conjugates of largest molecular weight. Nevertheless, for the purpose of the experiments described in Examples 6, 7 and 8, the pooled HRP-PLL fractions were used.OMPI EXAMPLE 3 CELLULAR UPTAKE OF HSA-PLL CONJUGATE COMPARED TO THAT OF UNMODIFIED HSAIn order to measure cellular uptake of HSA-PLL conjugate, conjugate was prepared using the procedure and reactants of Example 1 except that prior to reac¬ tion, some of the crystalline HSA was radioiodinated with 125I using the chloram T-iodmation procedure. See Sonoda, S. and Schlamowitz, M., Studies of 125I Trace Labeling of Immunoglobin G by Chloramin-T, Immonochem, 7_, 885 (1970) . The measurement procedure for cellular uptake was similar to that previously de¬ scribed by Ryser in Lab. Invest., 12, 1009 (1963) and also in Uptake of Protein by Mammalian Cells: An Un- derdeveloped Area, Science, 159, 390-6 (1968).Monolayers of L929 mouse fibroblast cells were grown to confluence in Eagle's MEM medium supplemented with non-essential amino acids and 10% fetal calf serum. Cell cultures containing unmodified labeled HSA and cell cultures containing labeled HSA-PLL were incubated for 60 mins. at 37° C in serum-free Eagle's MEM medium. After incubation, the monolayers of cells were washed twice with 5 ml of basal salt solution (BSS) at neutral pH and detached from the culture flask by brief- exposure to trypsin. The detached cells were washed twice by centrifugation and resuspension in 5 ml BSS, once by re- suspension in 5 ml heparin-containing BSS (5 mg/ml) and twice more with 5 ml BSS. The purpose of the wash in heparin-BSS was to remove HSA-PLL conjugates adsorbed to the cell surfaces by complexing the polycation part of the conjugate with the polyanion heparin. After this extensive washing procedure, these cells were dis¬ solved in IN sodium hydroxide. The protein concentration of this cell extract was determined by the method of Lowry as described by Lowry, 0. H., Rosebrough, N. S., Farr, A. L., Randall, R. J., Protein Measurement With the Folin Phenol Reagent , J. Biol. Chem., 193, pp 265-75 (1951) .Its 125 I radioactivity was measured m a gamma scintillation counter and expressed as j g of 125 I-HSA per mg of cell protein. This measurement was used as an expression of the cellular uptake of 125 I-HSA and of its PLL conjugate during the 60 min. incubation. The concentration of 125I-HSA either unmodified or conjugated form was 50 jug per ml of incubation medium throughout.Two experiments were performed, and both included a direct comparison between cellular uptake of labeled HSA-PLL conjugate and labeled HSA. In addition, the first experiment included a measurement of cellular uptake of labeled 125I-HSA when administered to the cells in the presence of 10 ug/ml of PLL and the second experiment included a measurement of the cellular up- take of labeled 125I-HSA when administered to the cells simultaneously with 50.ug/ml of non-labeled HSA-PLL conjugate.Cellular uptakes determined in this fashion were as follows:Uptake in 60 Min. (ug/ml cell protein) 125 I-HSA + 10 ug/ml PLL 0.41 125I-HSA + non-labeled HSA-PLL (50 jag/ml) 0 .77 . As can be seen from the data, an approximate ten¬ fold enhancement of cellular uptake was achieved by conjugation of HSA to PLL. Free poly-L-lysine of the same molecular weight, i.e., 6700, when added in amounts comparable to the PLL content of the conjugate (10 jjg/ml) did not cause any detectable enhancement of 125I-HSA uptake. Furthermore, when unlabeled HSA-PLL conjugate was added to unmodified 125I-HSA in the same amount(50 ig/ml) , it did not cause any significant effect on the uptake of 125I-HSA. These results indicate thatPLL serves as a carrier for the HSA protein covalently linked to it and significantly enhances transport ofHSA through the cell membrane compared to transport of unconjugated HSA. EXAMPLE 4REVERSAL OF ENHANCED CELLULAR UPTAKE OF HSA-PLL CONJUGATE BY TRYPSIN-TREATMENT The procedure of Example 3 was followed except that, prior to the experiments, part of the HSA-PLL conjugate was treated with trypsin. PLL is very sensi¬ tive to trypsin digestion, and enzymatic degradation of PLL in the conjugate would be expected to decrease the enhanced cellular uptake realized because of the PLL. A 0.3 ml aliquot of HSA-PLL (1.5 mg/ml) , prepared as in Example 1, was mixed with 30 ul of trypsin solu¬ tion (0.25%) and incubated for 5 min. in a 37° C water bath. The enzymatic reaction was stopped by diluting the 0.33 ml reaction mixture with 8.0 ml with Eagle's MEM medium containing 5% fetal calf serum (FCS) . This dilution brought the HSA-PLL concentration to 54/ιg/ml, which was roughly the same as in Example 3. Cellular uptake of the untreated HSA-PLL conjugate, of the trypsinized HSA-PLL conjugate, and of unconjugated HSA were measured following the procedure of Example 3. The results were:OMPIA P Uptake in 60 min. (ug/ g cell protein)125I-HSA-PLL (no FCS) 5.9125I-HSA-PLL (+5% FCS) 6.2 125I-HSA-PLL (+trypsin and+5% FCS) 3.2125■L DI-HSA 0.6As can be seen from the data, trypsin treatment of theHSA-PLL conjugate decreased its uptake by approximately 50% when compared to the uptake of the non-trypsinized HSA-PLL conjugate. This indicates that the enhancement of uptake is determined by the PLL-content of the HSA-PLL conjugate, and further trypsinization would have been expected to further decrease enhancement. The data also indicate that the 5% fetal calf serum used to terminate trypsinization did not, by itself, modify the cellular uptake of the HSA-conjugate. The figures obtained for the cellular uptake of HSA-PLL and HSA are in close agreement with the data of Example 3. EXAMPLE 5REVERSAL OF ENHANCED CELLULAR UPTAKE OF HSA-PLL CONJUGATE BY CARBAMYLATION OF THE AMINE GROUP OF THE PLL MOIETY The procedure of Example 3 was used, except that part of the HSA-PLL conjugate was first treated in the following manner.125One ml of I-HSA-PLL solution containing 1.5 mg conjugate per ml in phosphate buffered saline (PBS) , pH 7, was mixed with 16 mg potassium cyanate and then incubated at 25° C for 24 hours. After this, the solution was dialyzed extensively against PBS. More than 90% of the total pro-125 tern and of the I radioactivity was recovered after dialysis. This procedure is known to carbamylate all σC- and C-amino groups of PLL and thus to abolish the positive charge of PLL at neutral pH. See Stark, G. R. , Modification of Proteins with Cyanate, Methods Enzymol., 25B, 579 (1972) . Using the procedure of Example 3, the cellular uptake of 125I-HSA, 125I-HSA-PLL, and carbamylated125 I-HSA-PLL were measured at equal concentrations(50 jug/ml) . The results were: ' Uptake in 60 min.(ug/mg cell protein) ΔDI-HSA-PLL 5.02125I-HSA-PLL-CARB. 0.51125I-HSA (control) 0.44. As can be seen from these data, the uptake of 125I-HSA- PLL was increased compared to that of 125I-HSA by a factor of ten-fold, but carbamylation of the HSA-PLL conjugate abolished this enhancement and brought the cellular uptake back to control levels. This de on- strates that the enhanced uptake of HSA-PLL is due to the positive charges of the g-amino groups of the PLL- moiety in the conjugate. The figures obtained for the cellular uptake of HSA-PLL and HSA are in agreement with those of Examples 3 and 4. EXAMPLE 6CELLULAR UPTAKE OF HRP-PLL CONJUGATECOMPARED TO THAT OF UNCONJUGATED HRP ANDMEASUREMENT OF HRP ENZYMATIC ACTIVITYThe procedure of Example 3 was generally followed except that HRP and fractions of HRP-PLL obtained as described in Example 2 were employed instead of 125I-HSA and 125I-HSA-PLL, at a final concentration of 0.1 mg/ml.Following exposure to HRP and HRP-PLL, and after extensive washing, the detached cells were lysed in 0.05% Triton X-100, and the cell extract was used for the measurement of enzymatic activity of HRP in an assay employing di- anizidine as an electron acceptor. The rate of color development measured at 460 nm (Λ 4fin /min) was used as an indication of enzymatic activity, and the enzymatic activity measured in the cell extract was used as an expression of cellular uptake. The cellular uptake of'BUREOΛ'.PI enzyme following exposure of cells to single fractions of HRP-PLL (single fractions are described in Example 2 above) is shown in FIG. 1, as the dashed-dotted line. The cellular uptake of enzyme following exposure of cells to HRP or to the pooled HRP-PLL fraction (de¬ scribed in Example 2) were as follows.Cell-associated peroxidase Enzyme concentration activity (ΔA. ,_ /min/mg in medium (jjg/ml) cell protein) after exposure to: HRP HRP-PLL1500 1.55150 0.1415 — 7.331.5 0.30 0 (No measurable endogenous activity) As can be seen from these data, extracts of cells exposed to 15 ^g/ml HRP-PLL had 4.73-times more activity than extracts of cells exposed to a 100-times higher, and 43.1 times more activity than extracts of cells ex¬ posed to a 10 times higher concentration of unconjugated HRP. If corrected for exposures at comparable concen¬ trations, the cellular uptake of the 2 forms of peroxi¬ dase would thus differ by a factor of 473 and 431, respectively. When cells were exposed to 1.5 jag/ml HRP-PLL, cellular uptake was 2.1 times higher than in cells exposed to a 100-fold higher concentration and „ 0.194 times that of cells exposed to a 1000-fold higher concentration of native HRP. Corrected for exposure at equal concentrations, this corresponds to a 210- and 194-fold difference in cellular uptake between the 2 forms of HRP. There is a discrepancy between the over¬ all enhancement obtained when using 15 and 1.5 ^μg/ml HRP-PLL as a basis of comparison. There are at least two possible explanations for this discrepancy, i.e., preferential losses of HRP-PLL during the measurement procedure and preferential digestion of HRP-PLL by lyso- somes. Both would influence the measurements at low concentration of HRP-PLL more significantly. Thus, the factors of 473 and 431 appear more reliable as an index of enhancement. It should be noted that these values are based on measurements of enzymatic activity. Since the enzyme was only 40% active in the conjugated form, the index of enhancement for the cellular uptake of enzyme protein thus becomes 2.5 x 473, i.e., 1182- fold. The possibility must be considered that lyso- somal digestion of HRP-PLL might first attack the PLL moiety of the conjugate and transiently reactivate the enzyme, although attempts to reverse the 60% loss of activity in vitro have shown only minimal reactivation.EXAMPLE 7 CELLULAR UPTAKE OF HRP-PLL CONJUGATE COMPAREDTO UNCONJUGATED HRP:CYTOCHEMICAL STUDY To ascertain that the measurements of enzymatic activity reported in Example 6 express a true cellular uptake of .HRP and its conjugate, monolayers of L929 fibroblast were processed for cytochemical staining and cellular localization of the HRP reaction product. A. Cytochemical localization of HRP reaction product as observed by light microscopyMonolayers of L929 fibroblasts were incubated for various periods of time in serum-free Eagle's medium containing HRP and HRP-PLL conjugate in concentrations ranging from 1.5 to 150 jug/ml. The incubation procedure was as described in Example 3, except that cells were grown to non-confluent monolayers on glass coverslips made to fit the tissue culture tubes. The washing pro¬ cedure was modified as follows: after exposure to HRP, the monolayers were rinsed twice with basal salt solu- tion (BSS) . After transferring the coverslips bearing-BU EOMP W1P -37- the monolayers to clean tissue culture tubes, they were incubated for 5 minutes at 37° C in Heparin-BSS (5 mg/ml) , rinsed 3 more times with BSS and fixed for 20 minutes at 25° C with 2.5% glutaraldehyde in 0.1M cacodylate buffer, pH 7.4. After 5 rinses with cacodylate buffer, the cells were stained for 10 minutes with 0.5 mg/ml diaminobenzidine solution in 0.05 M tris-buffer, pH 7.6, containing a final concentration of 0.01% H-O^. After 4 more rinses in tris-buffer, and a fifth rinse in cacodylate buffer, the monolayers were fixed for 60 min. , at room temperature with 2% OsO. in 0.1 M cacodylate buffer. After 4 further rinses in cacodylate, the mono¬ layers were dehydrated and mounted on glass slides.Light microscopic observation, and photomicrographs therefrom, revealed minimal staining of HRP reaction products in the monolayer exposed for 60 min. to 150 jug/ml conventional HRP. In contrast, monolayers ex¬ posed to 1.5, 5, and 15 ug/ml of HRP-PLL showed a marked and dose-related staining. Since the exposure to 1.5^-tg/ml HRP-PLL gave markedly stronger staining than exposure to a 100 times larger concentration of unmodified HRP, and since the enzymatic activity of the modified HRP was 50% of the control HRP, it can be con¬ cluded that the conjugation of HRP to PLL enhanced its uptake more than 200-fold.B. Cytochemical localization of HRP-reaction product as observed by Electron Microscopy Monolayers of L929 fibroblasts were processed as described under Example 7A,. except that the monolayers were grown on glass coverslips coated with a carbon- film. The monolayers were processed as described in Example 7A until the completion of osmium fixation and the four subsequent rinses. They were then stained overnight at 4° C with 1% Uranylacetate, rinsed with distilled water, dehydrated and embedded in Epon. The carbon film with its cell monolayer detached from the glass and became part of the Epon bloc. Thin sections cut parallel to the plane of growth were observed in a Philips 300 Electron microscope. Electron microscopic pictures of cells exposed to HRP-PLL revealed horse¬ radish peroxidase reaction product in the form of abundant dark, densely stained opacities localized within endocytotic vesicles, throughout the cytoplasm, including the paranuclear areas. In contrast, cells exposed to a 100-times greater concentration of con¬ ventional HRP, showed minimal amounts of stained *{ reaction product. This finding proves that HRP-PLL conjugate are present within the cells following cellu¬ lar uptake and confirms that the conjugation of HRP with PLL increases its cellular uptake by more than 200-fold.It should be emphasized that this demonstration of the intracellular localization of the enzyme is based on its enzymatic activity inside the cell. Therefore, this demonstrates the possibility of dramatically increasing, by means of membrane transport, the intra¬ cellular content of a biologically active enzyme.EXAMPLE 8 CELLULAR UPTAKE OF HRP-PLL CONJUGATE: REVERSAL OF ENHANCEMENT FOLLOWING TRYPSIN TREATMENT OF THE CONJUGATE This experiment was carried out as described in Example 7A except that, prior to the experiment, part of the HRP-PLL conjugate was treated with trypsin. PLL is very sensitive to tryptic digestion and it was ex- pected that enzymatic degradation of the PLL moiety of the conjugate would decrease its cellular uptake. A 0.3 ml aliquot of HRP-PLL containing 0.85 mg/ml was incubated for 5 minutes in a 37° C water bath in presence of 30 of trypsin (0.25%) . The enzymatic reaction was stopped by 1:500 dilution with serum free growth medium to reach a final concentration of 1.5 μq HRP/ml. The cellular uptake of the trypsinized HRP-PLL was com¬ pared with that of the corresponding nontrypsinized preparation used at the same concentration (1.5 jug/ml) . Cells exposed to the trypsinized conjugate showed no sign whatever of intracellular HRP reaction product when observed under the light microscope. In contrast, cells exposed to 1.5 ιg/ml of HRP-PLL showed an amount of reaction product which was higher than that seen with amounts of 150 jig/ml unconjugated PLL. This result is consistent with that of Example 4 and demonstrates that the enhanced uptake of the HRP-PLL conjugate is indeed caused by the PLL-moiety of the conjugate. The experiment also confirms the difference in uptake of HRP and HRP-PLL noted in Example 7A.EXAMPLE 9 * COVALENT BONDING OF POLY(VINYLAMINE) TO HORSERADISH PEROXIDASE The procedures and reactants of Example 2 were used except that pol (vinyla ine) (PVA) of an average molecular weight of 20,000 was substituted for PLL. The weight of each of HRP, PVA and EDC were also re¬ duced from 20 mg to 5 mg and the reaction volume from 0.8 ml to 0.4 ml. The reaction product was loaded onto a SephadexG-100 chromatographic column (1.2 x 38 cm), equilibrated with phosphate-buffered-saline (PBS) and the column was eluted with PBS. Each 1 ml fraction was collected. Measurement of HRP activity in each fraction revealed a sharp and complete separation of two enzymatically active peaks, the second of which corresponded to native unreacted HRP. The first peak, eluting at void volume, corresponded to HRP-PVA, and was pooled. It showed slight turbidity indicating that the HRP-PVA conjugate is less soluble in PBS than the native enzyme. Protein concentration of the pooled HRP-PVA fraction was deter¬ mined by the method of Lowry et al. -40- EXAMPLE 10 CELLULAR UPTAKE OF HRP-PVA CONJUGATE COMPARED TO THAT OF UNCONJUGATED HRP, AND COMPARISON OF CELLULAR UPTAKE OF PVA- AND PLL-CONJUGATES OF HRPThe procedure of Example 6 was generally followed except that the pooled fraction of HRP-PVA obtained as described in the preceding example was used in addition to the pooled HRP-PLL fraction obtained as described in Example 2. The cellular uptakes of HRP-PVA and HRP-PLL were measured in the same manner. Following exposure to HRP, or one of its two conjugates, the monolayers of L929 mouse fibroblasts were washed and detached and the detached cells were washed as described in Example 3. The cells were then lysed and the cell extract used for measurement of enzymatic activity of HRP as described in Example 6. The cell-bound HRP activities following a 60-minute exposure to HRP, HRP-PVA and HRP-PLL were as follows: Cell-Associated Peroxidase Activity( A .,_ /min/mg cell protein)after Enzyme Concentration exposure to: 1.5 0 2.5 (0.30) (b)(a) Some cell lysis was observed at this HRP-PVA con¬ centration suggesting cellular toxicity. No such effect was seen at 1.5 ^μg/ml.(b) Result taken from the Table of Example 6 for com- parison.As can be seen from these data, conjugation of HRP to PVA, MW 20,000, markedly increases the cellular uptake of enzymatically active HRP by L 929 cell mono¬ layers. This increase is greater than that obtained with comparable amounts of HRP-PLL, especially at they^U lower concentration. This example demonstrates that conjugation of an enzyme to a cationic polymer other than a peptidic polymer can be at least as effective in enhancing the cellular uptake of active enzyme than conjugation to a cationic poly(amino acid).To ascertain that the measurement of enzymatic activity reported in this example express a true cellu¬ lar uptake of HRP-PVA, monolayers of L929 cells, exposed to HRP and HRP-PVA as described above, were processed for cytochemical staining and for cellular localization of the HRP reaction product as described in Example 7A. Light microscopic observations and photomicrographs therefrom confirmed that the differences in the enzyma¬ tic activity reported here express a true cellular uptake of HRP-PVA.EXAMPLE 11 COVALENT BONDING OF A CATIONIC TETRAPEPTIDE (TUFTSIN) TO HUMAN SERUM ALBUMIN (HSA)Tuftsin is a cationic tetrapeptide known to stimu- late phagocytosis in leucocytes by interacting with a specific membrane receptor. See Najjar, V. A. and Nishoka, K. , Nature, 228, 672-673 (1970); and Tzehoval, E. et al., Proc. Nat. Acad. Sci. U.S.A., 75, 3400-3404 (1978) . The procedure and reactants of Example 1 were used except that tuftsin was substituted for PLL, and that the weights of reactants and the reaction volume were modified as follows: 6 mg 125I-HSA. and 5 mg tuftsin were dissolved in 0.3 ml PBS to which 10 mg EDC was added. This solution was mixed and kept in the dark at room temperature for 16 hours, after which the reaction was stopped by dilution with PBS to 1.0 ml. This solu¬ tion was dialyzed at 4° C in 1 L PBS for 48 hours (one change of PBS at 24 hours) and recovered. There was total recovery of soluble radioactivity. EXAMPLE 12 CELLULAR UPTAKE OF HSA-TUFTSIN CONJUGATE COMPARED TO THAT OF UNMODIFIED HSA The procedure of Example 3 was generally followed except that the dialyzed solution of 125I-HSA-tuftεin obtained as described in Example 11 was substituted125 125 for I-HSA-PLL. The concentration of I-HSA free and conjugated form was 50 jug/ml of incubation medium throughout. Cell-bound activity was measured after 1 and 60 minutes of incubation and the difference (60-1 min) was considered to represent net uptake. The re¬ sults were:Uptake (CPM/ g cell protein)Enhancement (multiple of1 min. 60 min. 60-1 control5I-HSA 164.9 391.6 226.7 15I-HSA-Tuftsin 883.2 2126.8 1243.6 5.5x 5I-HSA-Tuftsin and50 jug/ml Tuftsin -646.4 1657.2 1010.8 4.6xAs can be seen from these data, an approximate5-fold enhancement of cellular net uptake was achieved by conjugating 125I-HSA to tuftsin. The addition of50 -ug/ml of tuftsin to the 50 ug/ml of 125I-HSA-Tuftsin conjugate decreased the net uptake of conjugate by approximately 20%, indicating moderate competition of the two compounds for membrane binding and uptake. These results indicate that the cationic tetrapeptide tuftsin, despite its small size, can serve as a carrier for the HSA covalently linked to it, and can enhance the transport of HSA through the cell membrane. The evidence of competition between tuftsin and HSA-Tuftsin suggests that the enhancement is related to binding of the tuftsin-moiety of the conjugate to tuftsin receptors at the cell surface. EXAMPLE 13 COVALENT BONDING (CONJUGATION) OF POLY-L-LYSINE (PLL) TO METHOTREXATE (MTX) AND TO H3-METHOTREXATE (H3-MTX) Methotrexate (MTX) was obtained from Sigma Chemical Co., St. Louis, Mo., and 3H-methotrexate (H3- MTX) sodium salt (250 juCi, 18.5 Ci/m mol) was obtained from Amersham Co., Arlington Heights, Illinois. Poly-L-Lysine (PLL) hydrobromide, MW 70,000, was obtained from Pilot Chemicals, Watertown, Ma. The carbodiimide reagent, l-ethyl-3-(3-dimethylaminopropyl) carbodiimide was obtained from Sigma Chemical Co., St. Louis, Mo.A 0.1 ml aliquot of methotrexate (MTX) solution (12 mg/ml, pH 7) was added to a small test tube con- taining 10 mg PLL, MW 70,000, in 0.5 ml H_0. After thorough mixing, 20 mg carbodiimide reagent was added and the mixture was incubated for 2 hours at 25° C with occasional shaking. The conjugate was then sepa¬ rated from the free MTX and other small molecules by Sephadex G-50 gel filtration. The MTX content of the various fractions was assayed by measuring their absorption at 257 nm in 0.1 N NaOH. See Seeger, D. R. , Cosulich, D. B., Smith, J. M. F. and Hultquist, M. E., J. Amer. Chem. Soc, 1__, 1753-1758 (1949) . The conju- gate came out of the column with the exclusion volume as a sharp symmetrical peak clearly separated from a minimal peak of unreacted MTX. More than 70% of the MTX used in the conjugation reaction was recovered in conjugated form. The conjugates of the pooled fraction had a MTX content of 8% on a weight basis corresponding to approximately 13 molecules per PLL molecule.To prepare labeled MTX conjugate, a 0.1 ml aliquot of a MTX solution (20 mg/ml, pH 7) was added to a vial3 containing solid H-MTX sodium salt (250 uCi, 18.5 Ci per m mol) . The final solution was adjusted to pH 73 with 1 N HCl and was kept frozen as a stock H-MTXSOLUTION (62.5 mCi/m mol) . The conjugation employed 3 0.05 ml of the H-MTX solution, added to a small test tube containing.5 mg PLL, MW 70,000, in 0.2 ml H20.Ten milligrams of carbodiimide reagent was then added and the reaction mixture was incubated at 25° C with occasional shaking. After 2 hours, the mixture was passed through Sephadex G-50 column for purification as described above.EXAMPLE 14CELLULAR UPTAKE OF H3-MTX AND H3-MTX-PLL CONJUGATE A Chinese hamster ovary cell line resistant to_ 3 RTTMTX (CHO Pro MTX 5-3) was obtained from Dr. W. F. Flintoff, University of Western Ontario, London, Ontario. A line of CHO wild-type cells from which the resistant cells had been derived (CHO WTT) was obtained from Dr. R. M. Baker, Massachusetts Institute of Technology, Cambridge, Ma.The 2 lines of CHO cells were grown as monolayers2 in Corning culture flasks with a flat surface of 25 cm(Corning Glass Works, Corning, N. Y.) 'in 5 ml Eagle's minimal essential medium, supplemented with pyruvate, vitamins and non-essential amino acids in the amounts contained in alpha medium.The growth medium contained 10% fetal calf serum, penicillin (50 U/ml) and streptomycin (50 ^g/ml) . Cul-4 tures were started with 5 x 10 cells per flask.Non-confluent monolayers were washed once with serum-free growth medium and incubated at 37° C in 5 ml. . . 3 3 serum-free medium containing either H-MTX or H-MTX-PLL at a MTX concentration of 1 x 10 M. The specific ac- tivities of both 3H-MTX and 3H-MTX-PLL were 72.5 mCi per m mole. The radioactive medium was removed at various times and the monolayers were washed twice with 5 ml Earle's balanced salt solution. Cells were then detached from the flask by brief exposure to trypsin. The cell suspension was centrifuged at low speed and the cell pellet was washed twice more with 5 ml balanced salt solution. The final pellet was dissolved in 1.0 ml 1 N NaOH and the protein content of each cell extract was determined by the method of Lowry. See Lowry,0. H., Rosebrough, N. S., Farr, A. L. and Randall, R. I., J. Biol. Chem., 193, 276-275 (1951). A 0.5 ml aliquot of the remaining cell extract was mixed with 5 ml Aquasol (New England Nuclear, Boston, Ma.) and counted in a liquid scintillation counter.FIG. 2 shows the cellular uptake of free and conju¬ gated methotrexate by the transport-proficient and transport-deficient cell lines as a function of time. The lower two curves represent the uptake of the free drug, and the upper two curves represent the uptake of3 the H -MTX-PLL conjugates. The conjugated drug is taken up much more readily than the free drug by both cell types. The uptake of free H -MTX by the transport- deficient cells is undetectable after 1 hour at the scale of Fig. 2, but is detectable in transport- proficient cells. When calibrated for comparable specific radioactivity of methotrexate, these measure¬ ments are in good agreement with those reported by Flintoff et al. See Flintoff, W. F., Davidson, S. V. and Siminovitch, L. , Somatic Cell Genet. , 2, 245-261 (1976); Flintoff, W. F. , and Saya, L., Somatic Cell Genet. , 4_, 143-156, (1978). The entry of free and conjugated drug differ not only in their magnitude but also in timecourse. In the case of the free drug, entry levels off after 30 minutes of exposure, while in the case of the conjugate, it is still increasing after 60 minutes. In transport-proficient cells, the accumulation of conjugated methotrexate is more than 20-fold greater than that of a free drug at 15 and 30 minutes, and more than 40-fold greater at 60 minutes. In transport-deficient cells, accumulation of conjugated drug is more than 200 times that of the free drug. EXAMPLE 15 GROWTH INHIBITORY EFFECTS AND MTX AND MTX-PLL CONJUGATE ON CHO WTT, CHO PRO~3 MTXRI1 5-3 AND CHO PRO~4 MTXRI1 4-5 CELLS The MTX transport-proficient and transport-defi¬ cient cell lines were grown for 24 hours. At that time either MTX or MTX-PLL were added to each flask to give final MTX concentrations ranging from 1 x 10 -9 to1 x 10 M. After 2 days of exposure, the monolayers were refed with fresh medium containing the same drug concentrations. After 2 more days the monolayers were rinsed with balanced salt solution, detached by brief trypsinization (0.25% solution from Grand IslandBiological Co.) and the suspended cells were counted in triplicate samples with a Coulter Counter. The cell count of random samples were verified using a hemocyto- meter. The results of these experiments are given inTable 1 and FIG . 3. TABLE 1KC3- Number' of' cells- x 10~β after days in presenceConcentrntion λdditionβ orExp. ,in growth medium Modifications •Ho drug MIX KTX-PL0 A.0610-7 3.51 0.1610 β 1.03 0.1110 β Tree PLL 1.63 . 5.0 yg/mlB 0 5.95As shown in Table 1, two different preparations of MTX-PLL used in different experiments were consid¬ erably more effective than the free drug in inhibiting the growth of MTX resistant cells. Free PLL at concen- trations chosen to match the amounts present in the conjugates was added to media containing either 10 or 10 M MTX and did not increase the effect of free MTX. This indicates that covalent linkage of the drug to PLL is necessary to increase its potency towards transport deficient cells. An aliquot of MTX-PLL was trypsinized in vitro'prior to its use in order to hydrolyze the polymeric carrier component. It was then compared to the intact conjugate for its growth inhibitory effect on transport deficient cells. As can be seen from the last two lines of Table 1, the trypsinized conjugate behaved like free MTX and had little or no inhibitory activity at a concentration of 10~7 M.The inhibitory effect of MTX on transport-pro- ficient and transport-deficient cells is compared in the dose-response diagram of FIG. 3. Approximately 100- times higher concentrations of free MTX were needed to cause comparable inhibitions in the transport- deficient line as indicated by the horizontal distance between the corresponding curves. However, when trans¬ port-deficient cells were exposed to the MTX-PLL conjugate, their dose-response curve was shifted to the left (solid curve) and became indistinguishable from that of free MTX-acting on drug sensitive cells (broken curve) . This suggests that the drug conjugate can overcome the transport deficiency inherent to the mutant line. Free and conjugated drug had approxi¬ mately identical effects on the drug-sensitive line.A second MTX-resistant, transport-deficient, mutant of CHO, described by Flintoff as CHO PRO-4 MTXRI1 4-5, was tested in similar fashion. The level of re- sistance of both mutant lines to MTX was found to be of comparable magnitude and the resistance was over¬ come by MTX-PLL in comparable fashion .EXAMPLE 16 CELLULAPv UPTAKE OF 3H-MTX AND ITSPLL OR PDL CONJUGATE BY— ■ _ -RTTCHO PRO MTX 5-3 CELLSThis uptake experiment was done on the CHO PRO MTX RII 5-3 cell line by the same procedure as described3 in Example 14, except that H-MTX-PDL was also tested. 3 H-MTX-PDL was prepared as described m Example 13 from poly-D-lysine hydrobromide, MW 60,000. The cells, after trypsinization, were washed once with 5 ml heparin solution (5 mg/ml) to eliminate any surface-bound poly- lysine since poly-D-lysine is not susceptible to trypsin digestion (See Examples 34 and 36) . The cells were then washed extensively with BSS and were dissolved in IN NaOH,The results of the cellular uptake of 3H-MTX, 3H-MTX-PLL3 and H-MTX-PDL after 1 and 60 mm. exposures were as follows:Cellular Uptake (cpπ,/mg cell protein)1 min 60 m±n 60 min-1 min3H-MTX 279 312 333H-MTX-PLL 600 6689 6089 3H-MTX-PDL 1106 7515 6409This shows that there is no significant difference be¬ tween MTX-PLL and MTX-PDL with regard to their cellular uptake.EXAMPLE 17 COMPARISON OF THE GROWTH INHIBITORY EFFECTSOF MTX-PLL AND MTX-PDL ON CHO WTT AND— • _ RTTCHO PRO MTX 5-3 CELL LINESThe MTX transport proficient and deficient cell lines were treated with MTX or its conjugates as de- scribed in Example 15. The concentration of the drugs—fi was 1 x 10 M of either free or conjugated MTX. MTX- PDL was prepared from poly-D-lysine hydrobromide withBUI __0Aj.PI a molecular weight of 60,000 and was the same prepara¬ tion as that used in Example 16. The growth inhibi¬ tory effects of MTX, MTX-PLL and MTX-PDL were as follows: Cell Line Number of Cells x 10 After 4 Days inPresence of:No Drug MTX MTX-PLL MTX-PDL WTT 4.80 0.37 0.29 4.46PRO-3 4.87 1.43 0.20 4.12—6 This shows that 1 x 10 M of MTX-PDL has no significant effect on either cell line. At this conce tration, however, even free MTX can inhibit the growth of the resistant cells. Since there is no differ¬ ence between the uptake of MTX-PLL and MTX-PDL by«—3 -RTT CHO PRO MTX 5-3 cells, as shown in Example 16, and since the outstanding difference between these two conjugates is that the PLL conjugate is susceptible to proteolytic digestion while the PDL-conjugate is no it can be concluded that the lack of biological effect of the MTX-PDL conjugate is due to the lack of intra¬ cellular digestion and of intracellular release of MTX or pharmacologically active MTX-derivatives.EXAMPLE 18 INHIBITION OF DIHYDROFOLATE REDUCTASE IN VITRO BY MTX AND MTX-PLLThe effect of MTX and MTX-PLL on dihydrofolate reductase was measured in the assay described in Stanl B. G., Neal, G. E. and Williams, D. C., Methods in Enzymology, eds. Colowick, S. P. and Kaplan, N. 0. (19 (Academic Press, New York) Vol. 18, pp 771-779. Dihyd folate reductase as well as the chemicals required for its assay were purchased from Sigma Chemical Co., St. Louis, Mo.The data are plotted in FIG. 4, and it can be see therein that the conjugate did not show any inhibition of dihydrofolate reductase in vitro at MTX concentra-—8 —7 tions of 10 and 10 M, while under the same assay conditions the MTX showed about 75% inhibition at 10 —8 M_7 and about 95% inhibition at 10 M. Prior treatment of the conjugate with 0.25 mg/ml trypsin or pronase par¬ tially restored the inhibitory effect on dihydrofolate reductase in vitro.Since the MTX-PLL conjugate has a strong inhibi¬ tory effect on growing CHO cells as shown in Examples 15 and 17 above, it must be concluded that a restora¬ tion of inhibitory activity comparable to that shown in this example is occurring inside the cells under the action of intracellular proteolytic enzymes.It can also be predicted that in vitro treatment of MTX-PDL with trypsin or pronase will not restore its inhibitory effect on dihydrofolate reductase in vitro.EXAMPLE 19 DETECTION OF INTRACELLULAR DEGRADATION PRODUCTS OF 3HrMTX-PLL AND 3H-MTX-PDL IN CULTURED CELLS EXPOSED TO CONJUGATES— -_ RTTMethotrexate-resistant cells, PRO MTX 5-3,2 were grown in a 75 cm flask and approximately one day before reaching confluence, were exposed for 24 hours at 37° C to 1 x 10~6 M of 3H-MTX-PLL and 3H-MTX-PDL. The labeled growth medium was then removed and the cell monolayers were washed twice with 15 ml buffered salt solution (BSS) . The cells were detached from the flask by brief trypsinization and washed three times by low speed centrifugation in 5 ml BSS. The last cell pellet was dissolved in 1 ml of 1% sodium dodecy- sulfate (SDS) in 0.01 M phosphate buffer, pH 7. A small amount (0.2-0.3 mg) of unlabeled MTX was added to each pellet before cell lysis as a carrier for traces of 3H-MTX the cell extract. The cell extract was then loaded onto a Sephadex G-25 column (1.5 x 24 cm) which had been equilibrated with SDS-phosphate-buffer and the column was eluted with the same buffer. Each 2-ml fraction was collected from the effluent of the column and 0.5 ml aliquots from each fraction were mixed with 5 ml Aquasol and counted in a liquid scin¬ tillation counter. The unlabeled MTX added to the cell extract as carrier was identified by measuring the absorbance of each fraction at 257 nm.FIG. 5 shows typical elution profiles of the extracts of monolayers exposed to H-MTX-PLL (upper 3 panel) and H-MTX-PDL (lower panel) . The arrows corre¬ spond to the total volume of the column. The solid curves show the radioactivity in each fraction, and the dotted curves indicate the unlabeled MTX added to the cell extract as carrier and internal marker. The cell extract from MTX-PLL treated cells shows a peak of radioactivity close to but not coincident with MTX. This peak, which represents about 25% of the total radioactivity in the cell extract, is believed to be a digestion product of MTX-PLL. No such peak is detected in the extract of cells exposed to MTX-PDL. The lack of such digestion product is consistent with the fact that PDL is not susceptible to hydrolysis by intracellular proteases. The conclusion that the small molecular peak of radioactivity represents an intracellular3 degradation product of H-MTX-PLL is further supported by experiments in which the 3H-MTX-PLL conjugate was digested in vitro. When the conjugate was exposed sequentially for 20 min, at 37° C to 0.25 mg/ml trypsin and protease and when the digest was loaded onto a Sephadex G-25 column comparable to the one used in this example, the elution pattern showed a peak of relative magnitude and of relative position comparable to the peak seen in the upper panel of Figure 5. These data indicate that neither intracellular nor in vitro digestion releases free MTX but released instead a small molecular adduct MTX. It is postulated that this digestion product is pharmacologically active and is responsible for the biologic effect of the MTX- conjugate. While the identification of this product is not yet completed, it is assumed that it represents lysyl- or dilysyl-MTX.EXAMPLE 20CELLULAR UPTAKE OF 3H-MTX-PLLIN THE PRESENCE OF AN EXCESS OF UNLABELED PLL_3 This uptake experiment was done using CHO PRO MTX RII 5-3 cells, following the same procedure as de¬ scribed in Example 14, except that the MTX concentra¬ tion of H-MTX-PLL was 1 x 10~7 M and that cells were2 grown in larger culture flasks (75 cm ) in order to ob- tain higher total radioactivities per monolayers. At-7 a MTX concentration of 1 x 10 M, the conjugate con¬ tained 0.5 jug/ml of PLL of molecular weight of 70,000. The incubation was carried out in the presence and absence of 5 jug/ml of free unlabeled PLL of the same molecular weight. The cellular uptake of labeled conjugate, expressed as CPM/mg cell protein, was as follows:PLL Concentration C Ceel!lular Uptake of 3H-MTX-PLL(ug/ml) (CPM/mg cell protein)Added inIn UnlabeledConjugate Form 1 min 60 min 60 min-1 min0.5 0 58 701 643 (100)0.5 5 ug/ml 54 573 519 ( 80) As revealed by these data, the addition of a 10-fold excess of unlabeled PLL to the medium decreases by 20%3 the cellular uptake of H-MTX-PLL. This result suggests3 that an excess of PLL, can compete with H-MTX-PLL for uptake, but only moderately so. Example 21GROWTH INHIBITORY EFFECT OF MTX-PLL IN THE PRESENCE OF AN EXCESS OF PLL AND PDLThis experiment was done with CHO PRO~3MTXRI1 5-3 cells and the procedure of Example 15 was followed excep that MTX was used only as conjugate, at only one concen¬ tration (1 x 10- *7 M) , and that increasing concentrations of unconjugated PLL and PDL were added together with the MTX-PLL conjugate. The PLL content corresponding to a 1 x 10~7 M MTX concentration of MTX-PLL is 0.5 ;ug/ml. The number of cells per culture flask after a 4 day exposure to 1 x 10~7 M MTX-PLL was expressed as precent of control cells grown in absence of MTX-PLL. The results were:MTX-PLL Addition Number of Cells (1 x 10-7 M) (μg/ml) (% of control)- - 100+ PLL 0 19+ 0.5 16+ 1.0 52+ 2.0 116+ 3.0 118+ 4.0 117+ PDL 0 20+ 0.5 25+ 1.0 79+ 2.0 112+ 3.0 115+ 4.0 114 These results show that addition of an increasing excess of PLL to the growth medium first decreases then totally abolishes the growth inhibitory effect of MTX-PL A marked decrease is seen already with a 2-fold excess (1.0 ug/ml) and total reversal is seen with a 4-foldBl3 O- . ■m W excess (2.0 ;ug/ml) . The same qualitative and quantita¬ tive pattern of protection was observed when PDL was added instead of PLL. As indicated in Example 17, PDL is not a suitable carrier for MTX because it is not susceptible to cellular hydrolases and therefore does not release pharmacologically active small molecular MTX-derivatives inside cells (see Ex-ample 19) . Des¬ pite these differences, PDL is as effective as PLL in decreasing the growth inhibitory effect of MTX-PLL. As shown in Example 20, PLL competes only moderately with MTX-PLL for cellular uptake. It must be concluded therefore that the marked protective effect of FLL result from a competition with MTX-PLL at a level other than cellular transport. At the highest concentration of PLL and PDL, the number of cells per culture flask exceeds that of the control cultures . This appears to be due to the fact that FLL and PDL increase adhesion of growing cells to the tissue culture flasks.Example 22 GROWTH INHIBITING EFFECT OF MTX-PLL CONJUGATEOF DIFFERENT MOLECULAR WEIGHTSMethotrexate (MTX) was conjugated with PLL of molecular weights of 3,100; 20,000; 70,000 and 130,000, using the procedure described in Example 13. These conjugates were purified by either Sephadex G-50 orSephadex G-25 gel filtration. The amounts of MTX per mg of PLL were almost identical for all four conjugates. However, the concentrated solution of the conjugate of lowest molecular weight contained some aggregates. The stock solution of this conjugate was therefore filtered and its MTX concentration was measured prior to each experiment. The growth inhibitory effects of these four conjugates at a MTX concentration of 1 x 10-'-7 M was determined on CHO PRO~3MTXR*rι 5-3 cells as described'BU EAU0- -PIΦ P -oo- e 15. The results were as follows:PLL M.W. of Number of CellsAdded MTX-PLL % of ControlControl(No MTX-PLL added) 100130,000 9.770,000 11.720,000 7.13,100 7.0. It is apparent from these results that, at a MTX concentration of 10- *7 M, no significant difference could be found in the growth inhibition caused by conjugates of PLL of molecular weights varying between 3,100 and 130,000. It is of interest to relate these results with those of Example 31 which demonstrate that the cellular uptake of radioiodinated PLL increased with their molecular weight. The fact that no similar correlation is found between molecular weight and biological effect of MTX-PLL suggests that there must be factors other than cellular uptake which limit the biological effect of MTX-PLL conjugates. The most obvious other factor is the rate of intracellular release of pharmacologi¬ cally active drug following cellular uptake. It can be postulated, therefore, that active MTX and/or active MTX-derivatives are more readily released following the uptake of small molecular MTX-PLL conjugates.Example 23 ANTITUMOR EFFECT OF MTX-PLL INJECTED INTRAVENOUSLY The P 1798 S/B tumor, a cortisol-sensitive and methotrexate-resistant lymphosarcoma, was passaged sub- cutaneously in BALB/c male mice weighing between 20 and 25 g. Cell suspensions were made by teasing minced pieces of tumor through a stainless steel screen, andOΛ-PI<- iP0 1 x 10' cells were injected subcutaneously in the left scapular region.The inoculation developed into a palpable tumor within 7-8 days and killed the animal on the average within 14 days. Following inoculation, mice were divided into 4 groups or 4 or 5 mice. One week or more after inoculation these groups were subjected to different treatments consisting of one daily injection of 0.2 ml of one of the following solutions: Group 1 (control), buffered saline; Group 2, PLL, (MW 2,700)1.56 mg/ml in buffered saline; Group 3, MTX, 0.125 mg/ml in buffered saline; Group 4, MTX-PLL conjugate con¬ taining 0.125 mg/ml MTX and 1.56 mg/ml PLL (MW 2,700) in buffered saline. In the first experiment, treatment was initiated on Day 12 after inoculation and consisted of a daily injection in the tail vein for 3 consecutive days. In the second experiment, the same treatment began on the 8th day after inoculation and was given for 4 consecutive days . All animals were sacrificed 1 day after the last injection. The subcutaneous tumors were carefully excised in toto and weighed. The results were:Experiment No. 1 Experiment No. 2Mean Tumor % of ■ Mean Tumor % ofGroup Weight (g) Controls Weight (g) Controls1 4.40 + 0.34a(4)b χ0o 4 .94 + 0.13 (5) 1002 4.56 + 0.45 (4) 103 5. .07 + 0.08 (4) 1033 4.53 + 0.28 (5) 102 4. .80 + 0.50 (5) 974 3.17 + 0.32 (5)c 71C 2. .47 + 1.54 (5)d 50d a Mean + SEM b Number of animals c P 0.005 when compared to any other group d P 0.001 when compared to any other group (includes 1 mouse that exhibited complete regression) . As can be seen from these data, the average tumor weight of animals receiving free MTX or PLL alone faile to show any reduction in either experiment. By con¬ trast, the animals receiving MTX-PLL conjugate showed reductions to 71% and 50% of the control weight in experiments 1 and 2, respectively. These reductions are statistically highly significant, when compared either to one of the other 3 groups. The greater weight reduction seen in the second experiment is consistent with the fact that in the second experiment, treatment was begun 4 days sooner and continued for one more day than in experiment 1.Two comparable experiments were carried out with a variant of the P 1798 lymphosarcoma known to be steroid-resistant and presumed to be MTX-sensitive. Treatment consisted of one daily intravenous injection for 4 consecutive days, and was begun on Day 11 and Day 12 post-inoculation in experiment number 1 and 2 respectively. All animals were sacrificed one day after the last injection. The results were:Experiment No. 1 Experiment No. 2 Mean Tumor % ofG oup. Weight (g) Controls1 5.25 + 0.42a (3)b 100 5 2 6.05 + 0.52 (4) 113 6.13 + 0.31 (4) ι023 4.58 + 0.31 (4) 85 5.29 + 0.40 (5) 884 4.68 + 0.26 (4) 87 5.26 + 0.11 (5) 88 a Mean + SEM b Number of animals These data show that in both experiments, the injection of free and conjugated MTX had comparable effects and caused a reduction of tumor weight between 85 and 88% of the control weight. These decreases are not statistically significant. The observation that administration of MTX-conjugate caused a lesser reductio of tumor weight than in the two experiments using MTX- resistant tumors suggests that the steroid resistant P 1798 tumor is partially resistant to MTX, for reasons other than defective MTX transport.Example 24SURVIVAL EXPERIMENTS USING LYMPHOSARCOMA-BEARING MICE TREATED WITH MTX AND MTX-PLL CONJUGATEFour groups of 8 BALB/c mice were inoculated sub- cutaneously with 1 x 107 cells of P 1798 S/B lymphosar- coma, a MTX-resistant, steroid-sensitive tumor. Treat¬ ment consisted of one daily 0.2 ml injection in the tail vein beginning on the sixth day after inoculation, and was continued until the death of the animal. The first two groups of mice served as controls and received 0.2 ml of either buffered saline (Group 1) or PLL(MW 2,700), 1.56 mg/ml in buffered saline. Group 3 received 1 mg/kg free MTX (0.025 g/injection) , and Group 4 received the same amount of MTX as Group 3, and the same amount of PLL as Group 2 in. the form of MTX-PLL conjugate. The number of surviving animals in each group was plotted as a function of time (days) and is shown in Figure 6. This Figure shows that the survival pattern of the two control groups is the same as that of Group 3, which received free MTX. In all three groups, the first death occurred on day 10 or 11 and the last survivor died on day 14. By contrasts, in the group receiving MTX-PLL, the first death occurred on day 15 and the last survivor died on day 21. Thus, the use of MTX-PLL conjugate prolonged survival by an average of 6 days. The longest survival measured from the initial treatment was 8 days in the group receiving free MTX and 15 days in the group receiving the MTX-PLL conjugate.A comparable experiment was carried out with the MTX-sensitive variant of P 1798 described in the previous*BlJKtATTOMPI Example. The data of this experiment are shown in Figure 7. As can be seen in this Figure, the two control groups showed an identical pattern of sur¬ vival, with the first death occurring at days 10 and 11 and the last death occurring at day 14. The two groups receiving either free or conjugated MTX stayed alive in the average 6 days longer than the controls. The first deaths occurred on day 16 and 17 in Groups 4 and 3 respectively, and the longest survival was 20 days in both groups. These data show that free and conjugated MTX have comparable effects when used in the treatment of an MTX-sensitive tumor. When measured from the initiation of treatment, the longest survival was 8 days in the control groups and 14 days in the experimental groups. When the two survival experiments are compared, it appears that the conjugated MTX has a comparable effect in animals bearing either the resistan or the sensitive form of P 1798 lymphosarcoma.Example 25 UPTAKE OF 3H-MTX AND 3H-MTX-FLL CONJUGATEBY P1798 S/B LYMPHOSARCOMA, IN VIVOThese experiments were carried out with BALB/c mice bearing either a MTX-resistant, steroid-sensitive tumor(P1798 S/B) or a steroid-resistant, presumably MTX- sensitive variant of P1798 S/B. Mice were inoculated subcutaneously with 1 x 107 tumor cells and used 12 days after inoculation at a time when the tumor weight was about 5 g. The tumor bearing animals received, in the tail vein, one injection of 0.2 ml 3H-MTX or 3H- MTX-PLL containing a total of 3.2 and 2.0 x 106 CPM, respectively. The 3H-MTX-PLL conjugate contained a PLL of 3,100 molecular weight. The amount of MTX in¬ jected as free MTX or MTX-PLL were 3.6 mg/kg and 3.2 mg/kg respectively. The mice were sacrificed 24 hours after injection, their tumors were excised and a tissue slice including the center of the tumor was minced and teased through a stainless steel grid to yield a cell suspension. Triplicate aliquots containing 5 x 106 cells were processed for radioactive measurements in a liquid scintillation counter, and the average counts were corrected for the different in total radioactivity injected as free or conjugated drug. The results of two typical experiments were: CPM Per 5 x 106 CellsTumor Type Exp. No. 3H-MTX(A) 3H-MTX-PLL(B) B/A MTX-resistant I 63 6169 98II • 94 6032 64.2 MTX-sensitive I 2099 5921 2.8 II 2240 4480 2.0These data demonstrate that intravenously injected -■-•H-MTX-PLL conjugate is readily taken up by both drug- resistant and drug-sensitive tumors in situ and that the uptake of conjugated drug far exceeds the uptake of free drug in both tumors. The average increase in uptake due to conjugation was 81-fold in the case of the drug- resistant tumor and 2.4-fold in the case of the drug- sensitive counterpart. The data show furthermore that, while the conjugated drug is taken up in comparable amounts by the resistant and senstive tumore, the free drug is taken up to a much lesser extent by the resis¬ tant tumor. This difference, which is of the order of 30-fold, strongly suggests that drug resistance of P1798 S/B is due to a deficient drug transport. These data are consistent with those of experiments measuring the cellular transport of the drug in cell suspensions derived from the P1798 S/B tumors. (See Example 26).OMPI. A EXAMPLE 26 UPTAKE OF 3H-MTX AND 3H-MTX-PLL BY CELL SUSPENSIONS OF P1798 S/B LYMPHOSARCOMA, IN VITRO A MTX-resistant tumor (P1798 S/B lymphosarcoma) and 5 a MTX-sensitive variant thereof were grown as subcutan¬ eous tumors in BALB/c mice as described in Example 23. Tumors of an average weight of 5 g were excised, minced RPMI 1640 tissue culture medium, and teased to yield cel suspensions. The disassociated cells were spun down to 10 a loose pellet and resuspended in fresh medium to a cell concentration of 5 x 10 cells per 3.0 ml of medium. Comparable suspensions prepared from both tumors receive either 4 x 105 CPM of 3π_MTX or 2.5 x 105 CPM of 3H-MTX- PLL conjugate. The H-MTX-PLL preparation was the same a 15 that used in Example 25 (PLL MW 3,100) . The molar con¬ centrations of MTX in the incubation medium of the sus¬ pensions exposed to MTX and MTX-PLL were 8.8 x 10 M and 7.3 x 10 M respectively. The suspensions were incu bated for 60 minutes at 37°C in a CO^-atmosphere, spun '20 down and washed twice with label-free medium. Triplicat aliquots of 1 x 10° cells were processed for radioactiv¬ ity measurements in a liquid scintillation counter, and the average counts were corrected for the difference in the total activity added as free conjugated drug. The 25 results of two such experiments were:CPM per 1 x 1Q5 CellsTumor Type Exp. No. 3H-MTX(A) 3H-MTX-PLL(B) B/AMTX-resistant I 277 10,050 36II 178 14,024 7930 MTX-sensitive I 2,094 10,549 5.0II 3,154 13,344 4.2These results show that, when exposed to MTX con¬ centrations of approximately 8 x 10 M, cells derived from the MTX-resistant tumor take up about 10-times less 35 free drug than those derived from the corresponding drug sensitive tumor, while both cell types take up nearly iάentical amounts of conjugated drug. The data also show that the conjugated drug is taken up much more readily than the free drug by either cell type and that conjugation increases the cellular uptake of MTX by an average factor of 57-folα and 4.6-fold in the case of the drug-resistant and drug-sensitive tumor cells respectively. These results are consistent with the data of Example 25. A comparison of the data'of Example 25 and 26 shows a difference in the relative uptake of free MTX by the cells derived from the MTX- sensitive and MTX-resistant tumor. This can be accounted for by the differences in concentration of MTX to which tumor cells were exposed in the in vivo and in vitro e_ eriments. The average ratios of MTX-PLL/MTX taken up by cells of the resistant tumor are of the same order of magnitude (81 and 57) and are indeed very large in both examples. The data of these two examples are also consistent with the previous results obtained with two MTX-resistant and -sensitive lines of Chinese Hamster Ovary cells (see Example 14) . They establish that the MTX resistance of the P1798 S/B tumor is indeed due to a deficiency in the membrane transport of MTX.Example 27 UPTAKE OF 3H-MTX AND 3H-MTX-PLLBY A HUMAN LYMEHOBLASTOID TUMOR LINEA human lymphoblastoid tumor cell line proficient in MTX transport and a mutant line thereof, deficient in MTX transport and hence drug resistant, were pro- viάed by Dr. John S. Erikson, from the Medical College of Pennsylvania. The cells were grown in RPMl 1640 medium containing 10% fetal calf serum.Uptake experiments were carried out using a microtest plate (Costar, 0.5 ml well volume). The wells contained 1 x 106 cells in 0.2 ml complete RPMl 1640 medium. Either free or conjugated 3H-MTX were added to a final MTX concentration of 1.1 x 10 ^ M and 1 x 10-4 M, respectively. The number of counts/well were 4 x 105 CPM and 2.5 x 105 CPM for 3H-MTX and3H-MTX-PLL, respectively. The 3H-MTX-1'LL preparation was the same as that used in Examples 25 and 26. Measurements were carried out in triplicate wells. The plates were incubated for 60 min. at 37°C in a 5% CO2 atmosphere:. At the end of incubation, each well was harvested unto filter discs using a Sketron AS harvester. The discs were dried, placed in 2 ml Liquiflor and counted in a liquid scintillation counter. The cell-bound 3H-MTX and 3H-MTX-PLL radioactivity of the triplicates was averaged and corrected for the difference in -total radioactivity added as free or conjugated drug. The results were:CPM per 1 x 106 Cells Tumor Type 3H-MTX(A) 3H-MTX-PLL(B) B/A MTX-resistant (mutant) 1,022 63,392 62 MTX-sensitive (wild type) 22,610 73,400 3.2These results show that the MTX-resistance of the human cell mutant is indeed due to a deficient MTX- transport and that the two human lymphoblastoid tumor lines used in this example behave essentially like the two urine lymphosarcoma P1798 S/B used in Examples 25 and 26, and the two CHO-lines described in Example 14.Example 28INHIBITORY EFFECT OF MTX AND MTX-PLL ON DNA SYNTHESIS OF A HUMAN LYMPHOBLASTOID TUMOR LINEThese experiments used the same two tumor cell lines as described in Example 27. In these two-phase experiments, the cells were first exposed to different concentrations of MTX and MTX-PLL and, after washing, were reincubated in the presence of 3H-thymidine. 3H-thymidine incorporation was used as an index of DNA synthesis and cell proliferation. Exposure to MTX occurred in multiwell plates. Cells suspended in a complete RPMl 1640 medium at a density of 2.5 x 10**-- l (2 ml per well) were exposed to MTX concentrations of 1.10-5, 1 x 10-7 and 1 x 10-*9 M given either as free or conjugated drug. The MTX-preparation was the same as that used in Examples 23 and 24 and had a PLL of 2,700 molecular weight. The multiwell plates were incubated for 24 hours at 37°C in a 5% CO2 atmos¬ phere after which the cells were washed twice with 2.0 ml of fresh medium. Triplicate aliquots (75 ul per well) of the washed suspensions were then reincubated in microwells °f a Costar microplate, diluted to 0.2 ml with culture medium and 50 μCi of H-thymidine (25 pi) was added to each well. After an 18 hour incubation at 37°C, the cells were harvested onto filter discs, using a Sketron AS cell harvester. The discs were then dried, placed in scintillation solution and counted in a liquid scintillation counter. The results of a typical experiment, giving the average DNA- associated counts of three wells as CMP/well or as percent of control cells, are presented in Table II below. TABLE 2Η-Thymidine incorporation into DNA of cells exposed toM (D Concentration No Drug TX HTX-PLLCell Type in Medium (M) (CP/I) (CPM) (%)A ICPM) { %)B A --h(2)MTX-Resistant 0 59,989 10-9 59,862 (101) 61,099 (104) 0 lO- 61,059 (103) 49,431 ( 84) 19 10-5 49,341 ( 84) 17,681 ( 30) 54MTX-Sensitive 0 64,568 10-9 62,5-7 ( 97) 68,234 (106) 010 -7 5i; 51 ( faO) 53,671 ( 91) 010 -5 15,679 ( 24) 24,439 ( 38) 0(1) Either in free or conjugated form(2) Increased inhibition obtained with drug in conjugated form (% of control)These data demonstrate that human tumor cells can be inhibited by MTX-PLL. They show that while human cells resistant to MTX are not, or only minimally, influenced by free MTX, they are strongly inhibited by MTX-PLL. Since this inhibitory effect is comparable in magnitude to that caused by MTX in MTX-sensitive cells, it can be concluded that the conjugated drug is capable of totally overcoming drug resistance in a human tumor cell line. It is apparent also that sensitive cells respond in similar fashion to both free and conjugated drug.The data presented in this example indicate that the growth inhibitory effects recorded on Chinese hamster ovary cells (Examples 15, 17 and 20) and on the murine lymphosarcoma P1798 (Examples 23 and 24) are relevant to the treatment of human tumors.Example 29COVALENT BONDING (CONJUGATION) OF THE NUCLEOTIDE ANALOG 6-MERCATOPURINE RIBOSYLPHOSPHATE (6-MPRP) TO PLLThe nucleotide corresponding to 6-mercaptopurine(6-MP) , namely 6-mercaρtopurine ribosylphosphate(6-MPRP) , was conjugated to PLL, MW 70,000, using the carbodiimide reagent, as described in Example 13 above. The reaction time was reduced to 1 hour at 25°C. Column chromatography of the reaction product on Sephadex G-50 gave a sharp separation of conjugated and free 6-MPRP. The 2 forms of 6-MPRP had comparable UV absorption spectra, indicating that conjugation had not caused any modification of the mercaptopurine moiety.Example 30CYTOCIDAL EFFECTS OF 6-MPRP AND 6-MPRP-PLL CONJUGATE ON L-929 FIBROBLAST CELLSCytocidal effects of 6-MPRP-PLL conjugate and of unconjugated 6-MPRP plus free PLL were compared using onolayer cultures of L-929 fibroblasts. Sparse mono¬ layers in phase of exponential growth were exposed to 1 x lO-5 M free or conjugated 6-MPRP for 1 h, 24h after inoculation. After exposure to the free or conjugated drug, the monolayers were kept growing for 2 days in standard growth medium, at which time no cytocidal effect could be detected. When the cells were subcultur and incubated for 7 additional days, the cells exposed to 6-MPRP-PLL failed to show any growth while cells exposed to a combination of f-ree 6-MPRP and free PLL grew at a rate undistinguishable from that of controls. A preparation of 6-MPRP-PLL that had been briefly trypsinized caused a 50% inhibition of cell growth. Under other experimental conditions, i.e., when 6-MPRP and 6-MPRP-PLL were present for the duration of the experiment at a concentration of 2 x 10 M, both compounds had inhibiting effects .The data obtained are plotted in FIG.' 8 and demon- strate: (1) that the 6-MPRP-PLL conjugate possesses biological activity; (2) that the conjugate can kill cells after a very short time of exposure in experimenta conditions under which the free nucleotide is ineffectiv and (3) that a nucleotide analog can be made to penetrat cells by employing PLL-conjugate.Example 31CELLULAR UPTAKE OF 125I-LABELED HOMOPOLYMERS OF L-LYSINESPoly-L-lysines of three different average molecu- lar weights, i.e., 38,000, 115,000 and 230,000, were radioiodinated using the Bolton-Hunter Reagent. SeeBolton, A. E. and Hunter, W. M., Biochem, J. , 133 , pp 529-38 (1973) . Unreacted 125ι-Bolton-Hunter Reagent was eliminated by chromotography on Biogel P-60 followed by extensive dialysis.Ut\ i- O. P y, WIP Monolayers of Sarcoma S-180, an established tumor cell line, were grown to confluence in Eagle's medium and were used to measure cellular uptake of I-PL . The poly-L-lysine concentration in the medium was 3 μg/ml throughout. The experiment was carried out following the procedure descri •be---d- m _ r -ExΛamTTTpDllee 3 for the measurement of 125J-.HSA except that measurements were made after one and sixty mins. of incubation at 37°C. The results, corrected for the relative purity and specific radioactivity of the three poly-L-lysine polymers, wereas follows: Uptake (ng/mg cell protein)60-min uptake of homopolymers of L-lysine increases linear y with their size. Example 32INTRACELLULAR BREAKDOWN OF INGESTED 125I-PLL BY SARCOMA S-180 CELL MONOLAYERSConfluent monolayers of Sarcoma S-180 were grown as described in Example 31. They were incubated for 60 minutes in serum free medium containing 0.2 ug/ml of125I-P L, of 115,000 molecular weight and high specific radioactivity. At the end of this incubation period, the labeled medium was removed and the monolayers were thoroughly washed with buffered salt solution (BSS) The monolayers were then reincubated in non-radioactive conditioned growth medium for various periods of time up to 24 hours. At each time, measurements were made of the acid soluble radioactivity both in the medium and in the cells. The acid soluble radioactivity of the medium was measured in the supernatant of medium treated at a final concentration of 20% trichloroacetic acid (TCA) . The acid soluble radioactivity of the cells was measured by trypsinization of the monolayers, thorough washing of the detached cells, and precipita¬ tion of their acid insoluble cellular components with a final concentration of 20% TCA. Figure 10 represents the results of a typical experiments and shows the generation of TCA soluble labeled breakdown product of -'- I-PLL as a function of time.The upper curve, corresponding to the acid solu¬ ble radioactivity of the culture medium, shows that labeled breakdown product of 12 l-PLL are released into the medium over the total period of reincubation and that this release increases linearly between 1 and 12 hours. By contrast, the cell-associated acid soluble radioactivity remained essentially constant over a period of 24 hours.These data suggest that PLL transported into cells during a 1 hour period of incubation is broken down inside the cell into small acid soluble products, of BUR OM which a small and constant amount is retained by the cell, while an increasing amount is excreted and -accumulates in the growth medium. It should be noted that the PLL was labeled with the Bolten-Hunter reagent and that the labeled lysyl or oligolysyl adducts, unlike the unlabeled lysine arising from intracellular digestion, cannot be reutilized by the cell for protein biosynthesis.Example 33CELLULAR UPTAKE OF 125I-PLL AND 125I-PDL BY A BHK CELL LINE HAVING A TEMPERATURE SENSITIVE MALIGNANT PHENOTYPEThis experiment was done with a baby hamster kidney cell line (BHK) transformed by exposure to dimethylnitrosamine (DMN) , growing with a non-malignant phenotype at 32°C and a malignant phenotype at 38.5°C. This temperature-sensitive mutant line, called BHK (DMNts) was described by G. DeMayora et al. Proc. Natl . Acad. Sci. U.S.A., 70, 46-49 (1973) . The cells were grown as monolayers in Dulbecco's high glucose medium. The transition from normal to transformed phenotype requires 3 to 4 population doublings or approximately 56 hours of growth at 38.5°C. The reversion to the normal, non-malignant phenotype likewise requires 3 to 4 population doublings or approximately 112 hours of growth at 32°C. PLL and PDL of average molecular weights of 125,000 and 130,000, respectively, were radioiodinated as described in Example 31. At time 0, the growth media of the confluent monolayers were replaced by serum free medium prewarmed to 37°C and containing 3 ug/ml radio- iodinated polymer. The monolayers were then incubated for 60 min, at 37°C. At the end of incubation, the cells were washed, detached, washed further and processed for measurement of 1 5ι radioactivity as described in Example 31. The results were as follows: Cellular Uptake in 60 min. (ng/mg cell protein) Phenotype PLL PDLNormal 525 ^JTransformed 75o 6β0 Transformed/Normal 1.43 •»These data show that PLL is taken up more effec¬ tively by cells of the transformed phenotype than by cells of normal phenotype. A comparable difference, however, is not apparent in the uptake of PDL. This finding suggests that malignant growth behavior may be associated with greater cellular uptake of PLL, and hence of PLL conjugate. This example of prefer¬ ential uptake is of interest because it would be highly desirable for the purpose of selective toxicity in cancer chemotherapy to achieve greater transport of cancer drugs into malignant cells .Example 34INTRACELLULAR BREAKDOWN OF INGESTED 125j_Tp-LL and l^x- D]-. Bγ BHκ (DMN) Ts CELLS AT PERMISSIVE AND NON-PERMISSIVE TEMPERATURESThis experiment employed the cells described in the preceding example. The cells were grown, and exposed to radiolabeled PLL or PDL as described in Example 33 except that the labeled polymer concentra- tion was approximately 0.3 pg/ml. After the 60 min. incubation at 37°C, the labeled medium was removed, and monolayers were thoroughly washed with buffered saline solution. An additional wash with saline con¬ taining 25 mg/ml dextran sulfate was carried out to remove surface-bound ***-25ι--polymers . The monolayers of cells with either phenotype were then reincubated for 24 hours at 32°C in the presence of unlabeled conditioned medium, after which the radioactivity of the medium and of the cells were measured separately. A second set of monolayers of either phenotype was re¬ incubated for 24 hours at 38.5°C and processed in similar fashion. The total radioactivity measured in the medium and in the cells was expressed as ng 125ι- PLL per mg cell protein. The results were:Radioactivity (ng 125I-PLL) per mg Cell ProteinTemp. of Phenotypic In Mediu (a) In C :ells Reincubation State PLL PDL PLL PDL32° Normal 13.6 3.29 12.4 21.5Transformed 20.4 3.63 11.3 30.138.5° Normal 20.6 4.87 11.8 20.1Transformed 26.9 6.06 9.7 35.7(a) A large fraction of the medium (35 to 60%) was acid soluble.These data show that the radioactivity introduced into the cells as -**- 5l-PDL tends to remain in the cells rather than to appear in the culture medium while a large fraction of PLL radioactivity disappears from the cells and is excreted into the medium. That the higher cell-bound radioactivity of cells exposed to 125.1-PDL is not due to a greater cellular uptake can be inferred from the data of Example 33, which show that cellular uptake of the two isomers is of compar- able magnitude. These data, together with those ofExample 32, provide independent evidence that ingested PLL is readily hydrolyzed inside the cells to small molecular diffusible breakdown products, while ingested PDL is not. These observations are consistent with those of Examples 16, 17, 18 and 19 comparing the properties of MTX-PLL and MTX-PDL, and of Example 36 comparing the stability of HSA-PLL and HSA-PDL complexes.More importantly, this Example shows that cells of the transformed phenotype tend to excrete a greater fraction of ingested PLL radioactivity into the medium than cells of a normal phenotype, suggesting a more efficient intracellular breakdown of PLL by cell of malignant phenotype. This difference is seen regardless of the temperature at which the experiment is carried out. This finding is of importance in view of the data we obtained with animal and human tumor cells(see Examples 23, 24 and 28). Indeed, for the purpose of selectivity in cancer chemotherapy with drug-poly (L-lysine) conjugate, it would be advantageous if a more effective breakdown of the PLL carrier occurred in malignant than in nόn-malignant cells.Example 35CELLULAR UPTAKE OF TRYPAN BLUE-PLL COMPLEXES COMPARED TO THAT OF FREE TRYPAN BLUETrypan Blue, an anionic dye commonly used in histology, has the property of being excluded by intact healthy normal cells and is often used to test the integrity of living cultured cells. We observed that when PLL of 70,000 MW is added to an aqueous solution of Trypan Blue, it forms non-covalent soluble com- plexes which posses totally different staining proper¬ ties than free Trypan Blue.Sparse monolayers of L 929 mouse fibroblasts grown on coverslips in Eagles medium were exposed over¬ night to growth medium con ianing 100 pg/ml Trypan Blue and 30 pg/ml PLL. The coverslips were thoroughly washed, fixed with 2.5% glutaraldehyde, dehydrated and mounted as permanent cytologic slides. Microscopic observation of these slides and photomicrographs thereof showed marked dye uptake by otherwise healthy looking cells. The cellular distribution of the dye was strikingly similar to that of horseradish peroxidase reaction products following exposure of cells to HRP-PLL, and described in Example 7A. The intensity of stain¬ ing was time and concentration dependent. Since the dye is totally excluded by healthy cells in the absence ofjURaOM PLL, and since PLL is readily taken up by cells (seeExamples 31, 32, 33 and 34) , it is concluded that in this instance, the dye is transported into cells as a PLL-complex in which PLL acts as a carrier molecule. Thus, a small anionic molecule can, under circumstances, form non-covalent complexes with PLL which are so strong as to assume the properties of covalent PLL- conjugates. This observation opens the possibility of using dye-PLL complexes for rapid screening of em- brane transport or tissue distribution of PLL.Example 36COMPLEXES OF POLY-L-LYSINE (PLL) , POLY-D-LYSINE (PDL) , POLY-L-ORNITHINE (PLO) , AND POLY-L-HOMOARGININE (PLHA) WITH HUMAN SERUM ALBUMIN (HSA) : THEIRSUSCEPTIBILITY TO TRYPSIN AND HEPARINIt was shown that free PLL and PDL when added to an incubation medium containing 125I-HSA had strikingly different effects on the cellular uptake of l25l-HSA. This difference propmted a study of their in vitro inter- . action with 125I-HSA. Both polymers were found to form in the persence of HSA, aggregates that could be quanti- tated by simple turbidity measurements in a spectro- photomer. PLL of low molecular weight, which—as previously reported—are unable to enhace the uptake of HSA, did not cause measurable aggregation of HSA in vitro. These two results suggested that in vitro aggregation might bear some relationship to the enhancement of HSA-uptake. Since in the standard procedure used to measure the cellular uptake of albumin, cell monolayers are detached from the culture flasks by brief trypsinization, the effect of trypsin on the poly(lysine)-HSA complex observed in vitro was investigated. HSA (0.5 mg/ml) and the poly(amine acids) (10 pg/ml) were mixed in a 3 ml cuvette in balanced salt solution (BSS) without phenol red. The change of absorption at 420 nm due to the turbidity was used as the measurement of the aggre¬ gate formation and dissociation. Trypsin solution (30 pi of 0.25%) was added at 15 minutes to both PLL 5 and PDL samples. Heparin solution (30 pi of 5 mg/ml) was added at 30 minutes to the PDL sample.FIG. 11 shows that the rate of aggregate formation initiated by the mixture of HSA and poly (lysines) can be follows spectrophoto etrically and that the rate is 10 identical for both isomers. When the turbidity had reached a plateau, the addition of trypsin completely dissolved the aggregates of HSA-PLL, but had no effect on the aggregates of HSA-PDL. The latter aggregate, however*, could be dissociated to a large extent by 15 the addition of 5 mg/ml heparin, a strong polyanion. Similar experiments were carried out with PLO and with PLHA except that the PLHA concentration was 30 pg/ml and trypsin was added after 30 minutes. The HSA-PLHA complexes showed intermediate susceptibility rrO to trypsin, as shown in FIG. 12.Those skilled in the art will recognize many equivalents to the specific embodiments of the invention described herein. For example, it is be¬ lieved that noncovalent bonding could be employed with 25 this invention if the bond strength approached that of covalent bonds. Such equivalents are considered to be part of this invention and are intended to be encompasse by the scope of the following claims .Industrial Applicability 0 This invention has industrial applicability in the clinical treatment of diseases, such as in the cancer and antimicrobial chemotherapeutic applications described herein. This invention can also be used in areas of drug therapy other than cancer and antimicrobial chemotherapy, whenever deficiency in cellular drug transport appears to be the cause of a poor response to drug treatment. Such areas may include metabolic, endocrine, cardiovascular and other diseases.Another area of application is the treatment of certain genetic diseases characterized by enzyme deficiencies. Several genetic diseases, especially storage diseases, are characterized by the absence or abnormality of specific lysosomal enzymes. In certain instances, these enzymes have deficient catalytic functions and fail to hydrolyze natural substrates present in lysosomes (e.g., sphyngo- lipidosis or glycogenosis) . In other cases, espe¬ cially in a mucopolysaccharidose called I-cell disease, enzymes have a normal catalytic function when tested in cell free systems but lack recognition markers responsible for their celluiar uptake and for their normal distribution in diseased tissues. In both instances, it would be important to have available for possible therapy enzymes having an increased ability to enter into the diseased tissue. While the results of enzyme therapy in these diseases have so far been disappointing, some modest beneficial effects have been observed in a few instances. It can be anticipated that such partial success will be improved by using polycationic conjugates of these enzymes to enhance their cellular uptake. Increased cellular uptake is also useful in areas employing protein or other macromolecules as biological markers. There are proteins, such as per- oxidases, ferritin, cytochromes, catalases, etc., which are useful biological markers because they or their reaction products can be visualized within cells using either light or electron microscopy. Horseradish peroxidase, for example, is taken up by nerve endings and transported along the nerve axons to cell bodies, and this phenomenom has been used successfully to study neuronal connections in the central nervous system. Any method to increase cellular uptake or decrease intracellular breakdown of such biological markers will increase their useful¬ ness in cell biology and/or neurobiology, since their effectiveness is usually limited by the ratio of their cellular uptake to their intracellular digestion, This invention may also be useful in enhancing the cellular uptake of protein hormones or poly- peptide hormones, such as insulin, especially when specific receptors for such hormones have been abolished or damaged by mutations or by diseases. There are many other applications, of course. Some of these could include the cellular transport of chelating agents, immunological agents, inter- feron, growth stimulating or inhibiting factors or other molecules having biological functions.The method could also be used to increase the cellular uptake of pesticides, including insecticides, etc.O P | CLAIMS1. A method of effecting cellular uptake of a molecule comprising covalently bonding said molecule to a cationic polymer to form a conjugate thereof and subsequently administering this conjugate to cells.2. A method of Claim 1 wherein the cationic polymer comprises a poly(amino acid), poly(amine) or sub¬ stituted polysaccharide.3. A method of Claim 1 wherein the cationic polymer comprises a poly(amino acid).4. A method of Claim 3 wherein said poly(amino acid) is selected from the group consisting of poly-L- lysine, poly-L-ornithine, poly-L-arginine, poly-L- homoarginine, poly-L-histidine, poly-L-diaminobutyric acid and optical-D-isomers and copolymers thereof.5. A method of Claim 3 wherein said poly(amino acid) is one which is broken down into normal physiologic by-products by proteolytic enzymes present in mammalian cells.6. A method of Claim 5 wherein said pol (amino acid) comprises poly-L-lysine or poly-L-arginine.7. A method of Claim 1 wherein said molecule com¬ prises a macromolecule.8. A method of Claim 3 wherein said molecule com- prises a macromolecule.9. A method of Claim 8 wherein said macromolecule comprises a protein. 10. A method of Claim 9 wherein said poly(amino acid) is poly-L-lysine.11. A method of Claim 10 wherein said protein com¬ prises a functional protein selected from an enzyme, a hormone, a growth factor, an immuno- globulin, an immunoglobulin fragment and a pro¬ tein having special transport properties.12. A method of Claim 3 wherein said macromolecule comprises a biologically active enzyme.13. A method of Claim 3 wherein said molecule com¬ prises a drug.14. A method of Claim 3 wherein said molecule com¬ prises a nucleotide.15. A method of Claim 3 wherein said molecule com- prises a nucleotide analogue.16. In the administration of a molecule to cells wherein the molecule is excluded or only poorly transported into cells under normal circum¬ stances: The improvement comprising increasing cellular uptake of said molecule by cova¬ lently bonding it to a cationic polymer which serves as a carrier to transport the molecule into said cells.17. An improvement of Claim 16 wherein said cationic polymer comprises a poly(amino acid).18. An improvement of Claim 17 wherein said molecule comprises a macromolecule. 19. An improvement of Claim 17 wherein said molecule comprises a drug.20. An improvement of Claim 17 wherein said molecule comprises a nucleotide.21. An improvement of Claim 17 wherein said molecule comprises a nucleotide analogue.22. A conjugate comprising a nucleotide which is poorly transported into cells covalently bonded to a cationic polymer, said conjugate having en- hanced cellular uptake compared to said nucleotide.23. A conjugate comprising a nucleotide analogue which is poorly transported into cells covalently bonded to a cationic polymer, said conjugate hav¬ ing enhanced cellular uptake compared to said nucleotide analogue.24. A conjugate of Claim 23 wherein said nucleotide analogue is 6-mercaptophosphoribosyl purine, cytosine arabinosylphosphate or adenosine arabino¬ sylphosphate.25. A conjugate comprising an antimicrobial drug which is poorly transported into cells covalently bonded to a cationic polymer, said conjugate having enhanced cellular uptake compared to said antimicrobial drug.26. A conjugate of Claim 25 wherein said antimicro¬ bial drug comprises adenosine arabinoside.BU EA U O.MPI y 27. A conjugate comprising a biologically active enzyme which is poorly transported into cells covalently bonded to a cationic polymer, said conjugate having enhanced cellular uptake com- pared to said biologically active enzyme.28. A conjugate of Claim 27 wherein said biologi¬ cally active enzyme comprises a lysosomal enzyme.29. In the administration of a cancer chemothera- peutic agent to cells wherein said agent is ex- eluded or poorly transported into said cells, the improvement of covalently bonding said agent to a cationic polymer to form a conjugate be¬ tween the agent and cationic polymer and subse¬ quently administrating said conjugate to the cells.30. An improvement of Claim 29 wherein said cationic polymer comprises a poly(amino acid).31. An improvement of Claim 30 wherein said cancer chemotherapeutic agent comprises a drug.32. An improvement of Claim 31 wherein said drug is selected from methotrexate, 5-fluorouracil, daunorubicin and deoxyrubicin.33. An improvement of Claim 30 wherein said cancer chemotherapeutic agent comprises a nucleotide.34. An improvement of Claim 30 wherein said cancer chemotherapeutic agent comprises a nucleotide analogue.BU OΦ WI 35. An improvement of Claim 34 wherein said nucleo¬ tide analogue comprises 6-mercaptophosphoribosyl purine.36. A process for effecting cellular uptake of an organic molecule which is excluded from or poorly transported into cells and which is capable of forming covalent bonds with cationic polymers, wherein the improvement comprises co¬ valently bonding said molecule to a cationic polymer which serves as a carrier to transport the molecule into said cells, prior to adminis¬ tering the organic molecule to the cells.37. A method for effecting cellular uptake of a biologically active enzyme comprising covalently bonding said enzyme to a poly(amino acid) selected from the group consisting of poly-L- lysine, poly-L-ornithine, poly-L-arginine, poly-L-homoarginine, poly-L-histidine, poly-L- diaminobutyric acid and optical-D-isomers and copolymers thereof.38. A method of adjusting to a predetermined level the cellular uptake of a conjugate formed from a molecule covalently bonded to a cationic polymer comprising forming said conjugate with a cationic polymer having a molecular weight sufficient to provide said predetermined level of cellular uptake.39. A method of Claim 38 wherein said cationic polymer comprises a pol (amino acid).40. A method of Claim 39 wherein said poly(amino acid) comprises poly-L-lysine.BUREAU O PI 41. A method of controlling the intracellular release of molecules covalently bonded to a cationic polymer to form a conjugate therebetween comprising employing a cationic polymer having a sufficient degree of intracellular digesti¬ bility to provide the desired intracellular release of molecules.42. A method of Claim 41 wherein said cationic polymer comprises a poly(amino acid) .43. A method of Claim 42 wherein said poly(amino acid comprises a digestible poly(amino acid) .44. A method of Claim 43 wherein said digestible poly(amino acid) comprises poly-L-lysine.45. A method of controlling the intracellular re- lease of molecules bonded to a cationic polymer to increase the cellular transport of said molecules by providing a spacer molecule be¬ tween said molecule and said cationic polymer, said spacer molecule being selected to provide the desired intracellular release.46. A method of Claim 45 wherein said cationic polymer comprises a poly(amino acid).47. A method of Claim 46 wherein said poly(amino acid) comprises poly-L-lysine.48. A conjugate comprising a molecule to be trans¬ ported into cells, a spacer molecule, and a cationic polymeric carrier.-WRE0 P1 49. A conjugate of Claim 48 wherein said cationic polymer comprises a poly(amino acid).50. A conjugate of Claim 49 wherein said pol (amino acid) comprises poly-L-lysine.51. A method of effecting cellular uptake of a molecule comprising forming a strong bond be¬ tween said molecule and a' cationic polymer to form a conjugate between said molecule and said polymer and subsequently administering this con- jugate to cells. | UNIV BOSTON | RYSER H; SHEN W |
WO-1979000516-A1 | 1,979,000,516 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | C01B17 | B01D53, C01G31 | B01D53, C01B17, C01G31 | B01D 53/34, C01B 17/05, C01G 31/00 | SOLUBLE COMPOUND OF VANADIUM | A gas mixture containing hydrogen sulphide is contacted with an aqueous alkaline solution to form bisulphide and thereby remove the hydrogen sulphide from the solution. The bisulphide reacted with a soluble vanadium (V) compound to form sulphur. The vanadium is subsequently reoxidised. The soluble vanadium compound is Na<u3>uVO<u4>u . 1/4NaOH.12H<u2>uO. It is prepared by adding sodium hydroxide to an aqueous solution containing vanadium (V) at elevated temperature, and then cooling the mixture. The amount of sodium hydroxide added is sufficient to increase the mole ratio of Na to V in the solution (preferably from at least 2:1) to at least 3:1 (and preferably to at least 6:1). | Soluble Compound of VanadiumThis invention relates to the preparation of a soluble compound of vanadium and to its use in gas purification.In the well known Stretford process for removal of hydrogen sulphide from a gas mixture containing hydrogen sulphide, the gas mixture is washed with an al aline aqueous solution (typically of sodium carbonate) so as to convert the hydrogen sulphide tσ (sodium) bisulphide. The bisulphide is then reacted with a soluble vanadium (V) compound which is dissolved in the aqueous solution. The bisulphide is consequently oxidised to sulphur, the vanadium being reduced to oxidation state IV. The vanadium is then reoxidised to oxidation state V by reaction with an oxidising agent which is also contained in the solution. The oxidising agent is of a kind which can be reoxidised by air or oxygen. The oxidising agent is typically anthraquinone 2, 7 disulphom'c acid. Thus, continuous regeneration of vanadium in oxidation state V is made possible. Moreover, the hydrogen sulphide is converted to sul hur which may be readily collected as a vendible product. In practice, the aqueous solution of vanadium (V) compound, alkali, and oxidising agent is prepared in a first vessel- and then passed into a second vessel where it is contacted with the gas mixture. The resulting sulphur-containing mixture is returned to the first vessel where it is blown with air to reoxidise the vanadium, to regenerate the oxidising agent and also to help the sulphur to rise to the surface of the liquid in that vessel. The sulphur may be collected from the surface. Substantially all the hydrogen sulphide is removed from the gas mixture, which is simply passed through the second vessel.Typically, a sequestering (or stabilising) agent such as sodium tartrate is included in the solution. Alternative oxidising agents to anthraquiπone which also function as sequestering agents are known. Vanadium (in oxidation state (V) has been added in various forms to the alkaline liquor, for example:1. As sodium etavanadate.2. By dissolving commercial vanadium pentoxide in the alkaline liquor.3. In the form of a soluble polyvanadate of sodium and ammonium. 4. As ammonium metavanadate. Whichever of these forms of vanadium is used, there is a loss of vanadium from the liquor by progressive precipitation of an insolubl form of vanadium, which may contain vanadium in oxidation state IV. In addition, some forms such as vanadium pentoxide are found to be difficult to dissolve and if they can be dissolved, this can be done only slowly. In the art, this is considered to be an important disadvantage. A further disadvantage associated with vanadium pentoxid is that it generally contains some vanadium in oxidation state IV (ie. it contains some V? ^ W^1C^ 1S inactive in the Stretford and analogous processes. In addition, ammonium is considered to be undesirable. by many users of the Stretford process who consequently do not use ammonium metavanadate or ammonium polyvanadate. There is thus a need for a new soluble compound of vanadium (V for use in the Stretford process.We have discovered that a soluble compound of vanadium of formula:Na3V04.l/4 NaOH.12H20 is surprisingly soluble in aqueous solution. Moreover, this compound is relatively stable in aqueous solution: the propensity of vanadium to come out of solution is relatively small. We have also found that the compound dissolves relatively quickly in water.The existence of this compound is reported by Chretien and Lelong in Compt. Rend. Ser. C 262 (6), pp 478-479 (1966). It is also referred to in Gmelins Handbuch der Anorganischen Che ie, System-Num er 48, Teil B - Lieferung 2 (1967), pp 382-383. An X-ray diffraction stud of the compound has been reported by E. Till mans and W H Baur, Acta Crystallographica, B27, pp 2124-2132 (1971), who found it hexagonal, space-group P 3 c 1, a=b=12.038 Angstroms, c=12.833 Angstroms. The X- ray diffraction method is probably the best way of characterising theOMPI vanadium compound.One characteristic of this vanadium compound that has been reported is a marked tendency for it to pick-up carbon dioxide from the atmosphere. It is believed that carbonate is formed, though, in general, an appreciable proportion of hydroxide remains. We have also found that the compound tends readily to give up at least some molecules of water of crystallisation on being heated. We have found that the compound is still very soluble even after pick-up of carbon dioxide and/or at least partial loss of its water of crystallisation.No method of preparing this compound has, we believe, been reported.According to the present invention, there is provided a method of removing hydrogen sulphide from a gas mixture containing hydrogen sulphide, including the steps of contacting the gas mixture with an aqueous alkaline solution to form bisulphide, dissolving a soluble compound of vanadium (V) in the solution, reacting the bisulphide with the soluble compound of vanadium (V) with the bisulphide to form sulphur, the vanadium being reduced to oxidation state IV, and reoxidising the vanadium to oxidation state V, wherein the soluble vanadium compound is:Na3Y04.l/4NaOH.12H20 or a product formed by driving off at least some of the molecules of water of crystallisation therefrom, and/or by the compound picking-up carbon dioxide.The invention also provides a method of preparing a vanadium compound of formula:Na3V04.l/4NaOH.12H20 wherein at elevated temperature an aqueous solution, containing 10 to 100 g/1 of vanadium (in odixation state V) has added to it 'sufficient sodium hydroxide to increase the mole ration of Na to V in the solution to at least 3, preferably to at least 6, and most preferably to 6.5 to 6.7 and then the solution is cooled so as to form crystals of the compound of vanadium.The solution mmay be of sodium metavanadate, or sodium orthovanadate or indeed any other compound of sodium, vanadium (V) and oxygen. The solution is preferably sodium vanadate liquor.It may be prepared by methods well known in the art. For example, sodium vanadate liquor may be prepared in accordance with theOMPI common practice in the industry, by roasting or fusing low grade vanadium bearing materials with soda ash, caustic soda or sodium salts in odixising atmosphere thereby converting the vanadium to sodium vanadate, and then extracting the so-formed sodium vanadate by leaching with water. The vanadate liquor preferably contains from 35 to 60 g/1 of vanadium. We have found that with sodium vanadate liquor below a vanadium concentration of 35 g/1, the yield of the oroduct decreases with decreasing vanadium concentration. Above a vanadium concentration of 60 g/1, we believe the magma of crystals which forms on cooling the liquor will be so dense that it will be difficult to handle. Typically the sodium vanadate liquor contains from 2 to 4.5 moles of sodium for every mole of vanadium.The elevated temperature is preferably at least 50°C, but is preferably below 100°C.The sodium hydroxide is preferably added in solid form so as to avoid dilution of the vanadate liquor. Care should be taken to avoi excessive temperature rise during the addition of the alkali. It is desirable to dissolve the alkali as quickly as possible. Thus, the vanadate liquor is preferably stirred vigorously throughout the additio of the alkali. The amount of sodium hydroxide which needs to be added depends on how much sodimm there is in the starting solution. Typically the mole ratio of Na to V in the starting solution is in the order of 2:1 up to about 4.5:1 though it may frequently be in the order of 4:1 if the starting solution is sodium vanadate liquor. In these circumstances sufficient sodium hydroxide may be added to increase the mole ratio to at least 5:1, preferably to at least 5.5:1 and most preferably to 6:1 to 7:1.As a result of dissolving the hydroxide in the vanadate liquor a clear solution is generally formed. This solution is preferably passed through a fine polishing filter to remove any particles of impurity and thus ensure that there is a clear solution. The solution is then preferably allowed to cool, preferably to ambient temperature. Desirably, the solution is stirred during cooling. As the solution cools so a thick magma of fine crystals forms.The crystals may be recovered by conventional means, such as filtration and ceπtrifuging. As much of the mother liquid as possible is desirably removed during the recovery of the crystals in view of their relatively high solubility. It is also desirable not to wash the crystals with water or other aqueous medium. This is to as to avoidURE;O PI - dissolving them.The crystals may, if desired, be dried at a temperature in the order of 45°C. If desired, before drying, the crystals may be purified by recrystallisation from water. Little change in composition is found in the case of the sodium salt. Generally, there may be a reduction of one percent in the total sodium present.The vanadium salt according to the invention is found empirically to have a composition (excluding water of crystallisation) as follows:% by weight Na 34.50V 23.520 balance, as determined by recrystallising to constant weight.Typically, the vanadium salt forms trigonal crystals which appear white to the eye.We believe that Na3V04.l/4Ha0H.12H20 is more soluble than vanadium oxides and sodium salts of vanadium previously used in the Stretford process. In addition, we believe that at least the novel sodium salt of vanadium has a greater stability than sodium ammonium polyvanadate.These advantages are illustrated below: 1. Solubility (in a g V/lOOg solution)Table 1Ammonium Fused Sodium Na3V0 4NaOH.12H20 metavanadate V2°5 ammonium. . polyvanadate- —Temp °C 20 20 20 80 30 70 30 70Water 0.25 1.29 Insoluble 0.45 4.2 3.8 12.3FreshStretfordLiquor 0.18 2.1 5.2 12.8SpentStretfordLiquor - 1.5 2.0 9.0•OMPI Fro these results, it can be seen that under all the conditions examined, the new vanadium compound according to the invention is considerably more soluble than any of the alternatives.2. StabilityIt has been reported that vanadium catalysts used in the Stretfo process diminish in activity with time due, it is claimed, to precipitation of part of the vanadium, and some users believe thi is related to the nature of the vanadium ionic species in solutiStability is usually tested by passing hydrogen sulphide gas, heavily diluted with nitrogen as an inert carrier gas, through freshly prepared Stretford liquor for several hours, and then sealing the vessel to exclude air. A stabiliser, typically tartaric acid, is present in the liquor (although citric acid ma be used instead). After some lapse of time, say 1 to 4 weeks, the liquor is filtered and any insoluble vanadium is estimated by analysis. The following results have been obtained using this procedure. The results relate to a 2 litre solution containing 1.7 g/1.Table 2 Insoluble Vanadium (g) from Sodium ammonium Na V04.l/4NaOH.12H201 week 0.303 0.5722 weeks 0.508 0.5643 weeks 0.615 0.4474 weeks 0.756 0.393While the mechanism is not clear it seems that vanadium at first precipitated from the new vanadium compound according to the invention redissolved, whereas the commonly used polyvanadates show progressive precipitation.We have also found there to be a marked improvement in stability when no stabiliser is present in the liquor. Example 1In this example, un-neutralised sodium vanadate liquor was used as a starting material.Four litres of un-neutralised vanadate liquor containing, in total, 196g (3.84 moles) of vanadium, and 374g (16.25 moles) of sodium (mole ratio of Na:V 4.2:1) were heated to 60°C, the liquor being stirred during the heating.The stirring was continued and 307.2g of sodium hydroxide pellets were added gradually to the mixture. This increases the mole ratio of Na:V. The stirring was continued and the mixture allowed to cool to room temperature, filtered and sucked dry through a vacuum filter to give 1.733kg of crude sodium salt of vanadium according to the invention.The resulting crystals were then raised in temperature to 105°C so as to drive off all moisture. It was found that as a result of this process 515 by weight of the dry solid was lost, ie. the solid contains approximately 51% by weight of uncombined water. It was found that the resultant solid contained 24.55* by weight of vanadium and 35.6% by weight of sodium. The filtrate was also subjected to analysis to find out how much vanadium it contained. It was found that the filtrate contained 10.4g/l of vanadium, the total volume of the filtrate being 2.721.It is to be appreciated that the preceding analysis of the crude sodium salt of vanadium was performed on only a small portion of that compound. The remainder was dissolved in 1.5 litres of demineralised water at 80°C, filtered hot and cooled. The resulting crystals were sucked dry by means of a vacuum filter and it was found that 1.017kg of crystals were obtained.An analysis of these crystals was conducted. A sample was taken and heated to 105°C to drive off all the uncombined water. It was found that the crystals contained 54* by weight of water of crystallisation. An analysis of the anhydrous crystals showed that they contained 24.9% by weight of vanadium and 35.1% by weight of sodium. This corresponds within the confines of the standard experimental error to a formula of a3V04. l/4NaOH.12H20.The filtrate was found to contain 33g/l of vanadium, and there was in total 1.51 litres of such filtrate.The above results show that the yield of vanadium in the pure sodium compound according to the present invention was 59.8% by weight. In order to verify that the compound prepared in a manner described above is that reported in the literature under the formNa3V04NaOH.12H20, a crystal of the substance was coated with UHU cement and mounted on a fibre. It was then subjected to an X-ray diffraction study. The crystal was stable for long enough for it dimensions to be deduced from oscillation and Weissenberg photogrIt was found that the substance crystallises in the hexagonal sys cell dimensions a=b=12.05 Angstroms and c=12.86 Angstroms. These conform well to those obtained by Tillimans and Baur.Example 2The compound of vanadium prepared by the method according invention was employed in the Stretford process on a pilot plant s The aqueous solution used to treat the gas mixture containing hyd sulphide contained sodium carbonate (as the alkali) and anthraqu n 2, 7 disulphom'c acid (as the oxidising agent) at conventional concentrations, tIn experiment A, sodium metavanadate was used as the vanad compound. In addition, a sequestering agent (or stabilising agent is sometimes called) sodium tartrate is present in conventional quantities. (The sodium tartrade being formed in situ by addition solution of tartaric acid).Experiment B involved the substitution of Na3V04.l/4NaOH.12 for the sodium metavanadate.Experiment C involved the omission of the sequestering age the solution, which was otherwise identical to that used in ExperiIn each Experiment, the starting concentration of vanadium 1.7g per litre. In each Experiment, the solution was blown with a as to regenerate the oxidising agent. Periodic additions of the v compound were made to the solution so as to restore its vanadium c to 1.7 g/1. Similarly, in Experiments A and B, periodic additions tartaric acid were made to replenish the tartrate.In each Experiment the rate of loss of vanadium from solut measured. In experiments A and B, the rate of loss of the tartrat al so measured.The results as shown in Table 3 below. It can be seen tha significantly less vanadium is lost in Experiments B and C than inBt Experiment A. Moreover, the results obtained in Experiments B and C are roughly comparable with one another, indicating that the method of removing hydrogen sulphide makes it possible to perform the Stretford process efficiently without using a sequestering or stabilising agent for the vanadium.Table 3Experiment Rate of entry of Hrs of Operation Rate of Rate ofH2S (in 1/hr) loss of lass of tartrate V %/day %/day4.4 145 6.3 15.73.8 167.5 7.6 8.63.8 263 7.9 | CLAIMS1. A method of removing hydrogen sulphide from a gas mixture containi hydrogen sulphide, including the steps of contacting the gas mixtu with an aqueous alkaline solution to form bisulphide, dissolving a soluble compound of vanadium (V) in the solution, reacting the bisulphide with the soluble compound of vanadium (V) with the bisulphide to form sulphur, the vanadium being reduced to oxidatio state IV and reoxidising the vanadium to oxidation state V, wherei the soluble vanadium compound is:Na3V04.l/4NaOH.12H202. A method of preparing a vanadium compound of formula:Na3V04.l/4NaOH.12H20wherein at elevated temperature an aqueous solution containing in 10 to 100 g/1 of vanadium in oxidation state V has added to it sufficient sodium hydroxide to increase the mole ratio of Na to V in the solution to at least 3 and then the liquor is cooled so as to form crystals of the compound of vanadium.3. A method as claimed in claim 2, in which the mole ratio is increas to at least 5:1.4. A method as claimed in claim 2 or claim 3, in which the starting solution is sodium vanadate liquor, formed by roasting of fusing l grade vanadium bearing materials with soda ash, sodium hydroxide or a sodium salt in an oxidising atmosphere, and then leaching the resulting solids with water.5. A method as claimed in any one of claims 2 to 4, in which the mole ratio of Na to V is increased to at least 6:1.6. A method as claimed in any one of claims 2 to 5, in which the mole ratio of Na to V is increased from a value in the range 2 to 4.5. a value of at least 5.5.7. A method as claimed in any one of claims 2 to 6, in which the solu contains 35 to 60 g/1 of vanadium. /^BU REΛ( °MPI ~ ΪPO~ 8. A method as claimed in any one of claims 2 to 7, in which the elevated temperature is above 50°C and below 100°C.9. A method as claimed in any one of claims 2 to 8, in which the sodium hydroxide is added in solid form. \10. A method as claimed in any one of claims 2 to 9, in which the solution is cooled to ambient temperature. AMENDED CLAIMS (received by the International Bureau on 8 June 1979 (08.06.79))1. A method of removing hydrogen sulphide from a gas mixture containing hydrogen sulphide, including the steps of contacting the gas mixture with an aqueous alkaline solution to form bisulphide, dissolving a soluble compound of vanadium (V) in the solution, reacting the bisulphide with the soluble compound of vanadium (V) with the bisulphide to form sulphur, the vanadium being reduced to oxidation state IV and reoxidising the vanadium to oxidation state V, wherein the sol ble vanadium compound is:Na3V04.l/4NaOH.12H20 or a product formed by driving off at least some of the molecules of water of crystallisation from the compound, and/or by the compoun picking up carbon dioxide.2. A method of prepar ng a vanadium compound of formula: * Na3V04.l/4Na0H.12H20wherein at elevated temperature an aqueous solution containing in 10 to 100 g/1 of vanadium in oxidation state V has added to it sufficient sodium hydroxide to increase the mole ratio of Na to V in the solution to at least- 3 and then the liquor is cooled so as to form crystals of the compound of vanadium.3. A method as claimed in claim 2, in which the mole ratio is increased to at least 5:1.4. A method as claimed in claim 2 or claim 3, in which the starting solution is sodium vanadate liquor, formed by roasting of fusing low grade vanadium bearing materials with soda ash, sodium hydroxide or a sodium salt in an oxidising atmosphere, and then leaching the resulting solids with water.5. A method as claimed in any one of claims 2 to 4, in which the mole ratio of Na to V is increased to at least 6:1.6. A method as claimed in any one of claims 2 to 5, in the role ratio of Na to V is increased from a value in the range 2 to 4.5. to a value of at least 5.5. ^-r- n cOMP 7. A method as claimed in any one of claims 2 to 6, in which the solution contains 35 to 60 g/1 of vanadium.8. A method as claimed in any one of claims 2 to 7, in which the elevated temperature is above 50°C and below 100°C.9. A method as claimed in any one of claims 2 to 8, in which the sodium hydroxide is added in solid form.10. A method as claimed in any one of claims 2 to 9, in which the solution is cooled to ambient temperature. STATEMENT UNDER ARTICLE 19The Applicants wish to amend claim 1 of the above application by adding to it after the chemical formula the words ...or a product formed by driving off at least some of the molecules of water of crystallisation from the compound, and/or by the compound picking carbon dioxide. Accordingly, three copies of an amended set of claims are attached hereto. | COUCH C; MUREX LTD | COUCH C |
WO-1979000521-A1 | 1,979,000,521 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | C08L33 | A61K5, C04B13, C04B19, A61L15 | A61K6, A61L15, A61L27, C04B28, C08F20, C08F220, C08K3, C08L33 | A61K 6/083M, A61L 15/12+C08L33/02, A61L 27/44R+C08L33/02, C04B 28/28, C08K 3/00+L33/02 | HARDENABLE COMPOSITIONS | Compositions which are hardenable in the presence of water to form a poly (carboxylate) cement contain a metal salt which accelerates the setting of the composition. | - l -HARDENABLE COMPOSITIONS This invention relates to hardenable compositions comprising a particulate ion-leachable silicate or aluminosilicate; to cement packs comprising a particulate ion-leachable silicate or aluminosilicate and a poly(carboxylic acid)} to hardened cements formed by reacting the particulate ion-leachable silicate or aluminosilicate with the poly (carboxylic acid) in the presence of water; to processes for preparing such cements; to mixtures useful in preparing such cements; and to products formed by utilising the cements. In our Complete Specification No. 1,422,337 we have disclosed that improvement in the rate of hardening of such cements, Conventionally called poly(carboxylate) cements , is obtained by the addition thereto of a chelating agent. Specifically, we have described and claimed a process for the production of a poly(carboxylate) cement which comprises mixing a water-soluble poly(carboxylic acid) having a relative viscosity from 1.05 to 2.00 with a cement powder in the presence of a water-soluble chelating agent and water to give a plastic mass which rapidly hardens to form a poly(carboxylate) cement. We have also described and claimed poly(carboxylate) cement packs and cement-forming liquids for the use in such processes, as well as poly(carboxylate) cements formed by such processes.It is desirable to be able to improve still fur her the control over setting times for poly(carboxylate) cements, particularly having regard to the diverse and often specialised applications to which these cements are increasingly being put. According to the present invention, there is provided a hardenable composition which comprises (i) a poly(carboxylic acid) or precursor thereof (as herein defined); (ii) a particulate ion-leachable silicate or aluminosilicate reactable with (i) in the presence of water or set to a hardened composition; and (iii) a metal salt which accelerates the setting of the composition. It has been found that certain silver (I) salts or barium salts, for example silver nitrate, barium chloride or barium fluoride, may be utilised in accordance with compositions of this. . . • invention. However, in general (iii) comprises a multivalent metal salt the cation of which either has a high ionic potential(ionic charge/ionic radius), generally above 2.1, or is capable of forming complexes. Apart from the above mentioned exceptions, it is found empirically that such cations are those of a metal less electropositive than sodium, generally having a standard electrode potential E less than 2.6 volts. Suitable such salτs ox are those of aluminium, cadmium, magnesium, mercury (II), silver (II) or zirconium, especially aluminium, magnesium, silver (II) or zirconium. Further suitable such salts are the fluorides, for example aluminium fluoride, magnesium fluoride, stannous fluoride, silver (II) fluoride or zinc fluoride.Preferably, such salts (iii) are soluble in an aqueous solution of (i).In accordance with a further aspect of the invention, there is provided a hardenable composition as hereinabove defined which further comprises a complexing agent soluble in an aqueous solution of (i). The complexing agent may comprise a fluoride ligand or, more preferably, a chelating agent. The chelating agent may comprise a plurality of carboxyl groups, for example aconitic, itacόnic^.raale c me-11'itic or _t'ri.carballfc.acid; it may also comprise at least one hydroxyl group. Particularly preferred such chelating agents comprise citric, malic or* tartaric acid. A further suitable type of chelating agent comprises a multivalent metal chelate, the metal of which may suitably be the same as that in (iii), for example a beta-diketone chelate, such as is formed by aluminium or chromium, or an EDTA chelate, such as is formed by copper or zinc.Such chelating agents are suitable present in an amount up o 20% by weight, preferably 0.1% to 10% by weight, especially 3% to 8% by weight, based on the weight of (i).Preferred hardenable compositions according to this invention are those which comprise a chelating agent as hereinabove described and wherein (iii) comprises a multivalent metal fluori'de, including barium fluoride; or a mutilivalent metal chloride, including copper, stannous and zinc chloride, the cation of which o has a standard electrode potential E less than 2.6 volts. oxSuitably (iii) is present in an amount of up to 15% by weight, preferably 1% to 10% by weight, based on the weight of (i). Desirably, the weight ratio of (iii) to the chelating agent is from 15:1 to 1:15, 'preferably 3:1 to 1:3. The preferred poly(carboxylic acids) suitable for use as (i) are those prepared by the homopolymerisation and copoly- merisation of unsaturated aliphatic carboxylic acids for example aconitic acid,t acrylic acid, citraconic acid, fumaric acid, glutaconic acid, itaconic acid, maleic acid, mesaconic acid, methacrylic acid, and tiglic acid; and the copolymerisation of these acids with other unsaturated aliphatic monomers for example vinyl monomers, such as vinyl hydrocarbon monomers, vinyl ethers, acrylamide or acrylonitrile. Particularly preferred are the homopolymers of acrylic acid and its copolymers with one or more of aconitic, fumaric, itaconic, maleic, mesaconic, methacrylic muconic or tiglic acid, particularly copolymers of acrylic acid and itaconic acid. Especially preferred are those described and claimed in our Complete Specification No. 1484454. Good results have also been obtained using a copolymer of vinyl methyl ether and maleic acid.It is also possible to use a precursor of a poly(carboxylic acid) as (i); as used in this specification, precursor1* means a polymer which will be transformed into the poly(carboxylic acid) on hydrolysis, for example a pol (carboxylic acid anhydride); furthermore, polyacrylic acids may be prepared by hydrolysis of corresponding polyacrylonitriles. The precursor of a poly (carboxylic acid) may be a homopolymer of an unsaturated carboxylic acid anhydride or a copolymer with an above mentioned other carboxylic acid or anhydride thereof; or a copolymer of an unsaturated carboxylic acid (anhydride) with an unsaturated aliphatic monomer, for example vinyl monomers, such as vinyl hydrocarbon monomers, vinyl ethers, acrylamide or acrylonitrile. Good results may be obtained by using homopolymers of maleic anhydride or vinyl orthophthalic anhydride, or copolymers thereof, especially block copolymers thereof, with ethylene, propylene, butenes, styrene, and vinyl methyl ether.The poly(carboxylic acid) or precursor thereof is preferably linear, although branched polymers may also be used. Preferably, the polymer has an average molecular weight from 1,000 to 1.000,000, more preferably from 1,000 to 250,000, and most preferably from 5.000 to 100,000, especially from 10,000 to 25<000. In this specification the average molecular weight is defined as being that measured by ultracentrifuging. The preferred particulate ion-leachable silicates or aluminosilicates (ii) are glasses wherein the ratio by weight of acidic to basic oxides in the glass is such that the glass will react with (i) in the presence of water to set to a hardened composition. The principal acidic oxide in the aluminosilicate glass is a silica, although the glass may also contain minor amounts of other anhydrides such as phosphorus pentoxide and boric oxide. The principal basic oxide in the glass is alumina which, although it has arπphoteric properties, can be considered for the purposes of the present invention solely as a basic oxide. Particularly preferred alumino-(. silicate glasses fall within the composition range of 10 to 65% w/w silica and 15 to 50% w/w alumina.The aluminosilicate glass desirably contains at least one other basic oxide, preferably calcium oxide, which may be present in the glass composition in an amount from 0 to _>0% w/w. The calcium oxide may be partly or wholly replaced by sodium oxide or other basic oxide or a mixture of basic oxides, although in some applications the presence of sodium- oxide may be undesirable as this oxide tends to increase the solubility of the resulting cement. Preferred glasses for use in the present invention containing alumina, silica and calcium oxide are the gehleni:te and anorthite glasses, and in general glasses falling within the composition range 10 to 65% w/w silica, 15 to 50% w/w alumina and 0 to 50 w/w calcium oxide. Other aluminosilicate glasses suitable for use in the present invention may contain fluoride, suitably up to 15% by weight preferably less than 10% by weight. A class of fluoroaluminosilicate glasses particularly suited to dental applications are those wherein the ratio by weight of silica* to alumina is from 1.5 to 2.0 and the ratio by weight of silica to alumina is from 0-5 to 1«5 and the ratio by weight of fluorine to alumina is from 0.25 to 2.0.The aluminosilicate glasses suitable for use in the present invention may be prepared by fusing mixtures of the components in the appropriate proportions at temperatures above 900 C and preferably in the range of 1050 C, The mixture is preferably fused from 1 to 4 hours. Silica and alumina may be included in the mixture as oxides, though it is convenient to add calcium oxide and sodium oxide as calcium carbonate and sodium carbonate respectively, and reference to the presence of these oxides in a glass fusion mixture includes the possibilities that they may be added as carbonates or as other compounds which decompose similarly under glass fusion conditions to give the oxides. The addition of carbonates to the fusion mixture lowers the fusion temperature and thus these can be considered as fluxing agents. If desired, however, the mixture may contain an additional fluxing agent, and this has been found to be important with glass compositions containing less than 10% w/w of calcium oxide. In this connection, fluorides such as fluorite and cryolite have been found to be especially useful ' as fluxing agents, although it is desirable not to use large amounts of fluorides in the fusion mixture. Other fluxing agents, for example calcium phosphate and aluminium phosphate may also be used. The total amount of fluxing agents present in the mixture, including carbonates, may be up to 50 by weight, based on the total weight of mixture.After fusion the glass may be poured off and cooled rapidly, for example, in air or water or some combination of both. To the first approximation the proportions of the same elements are present as inthe mixture. Some fluorinemay, however, be lost from the fluoride fluxing agent during the reaction.Glasses used in the present invention may be readily obtained in fine powder form. The degree of fineness of the powder should preferably be such that it produces a smooth cement paste which sets within an acceptable period when mixed with the poly(carboxylic-.acid) in the, presence of water. Preferably the degree of fineness of the powder is such that it will pass through a 150 mesh B.S. sieve and most preferably such that it will pass through a 50 mesh B.S. sieve. Mixtures of different glasses may be used if desired. Preferred are (fluor)alumiπosilicate glass powders.The silicate may also be a naturally-occurring ortho- silicate, pyrosilicate. cyclic or chain silicate comprising recurring metasilicate units, or aluminosilicate having an Al.Si molar ratio greater than 2-3; °r blast furnace slags; or Portland cement. Examples of such materials include aphrosiderite, danalite, gehlenite, hemimorphite, larnite, levynite, nepheline, muscovite, solalite, scolecite, spurrite. thuringite, willemite, wollastonite. (including calcined wollastonite).This invention also provides a mixture, which may be aqueous, of a metal salt (iii) as herein defined with a complexing agent as herein defined, or a pol (carboxylic acid) (i) as herein defined, or both. In the absence of water the poly(carbox ]ic acid) may be present as a precursor, as herein defined. The hardenable composition of the invention mα;, be supplied or stored in any suitable manner providing 'that means are provided to prevent reaction of the ion-leachable particulate material (ii) with the poly(carboxylic acid) (i) in the presence of water. Thus, the composition may be supplied or stored as a dry mixture, suitably comprising an intimate powder, of the poly(carboxylic acid) or precursor thereof (i) in particulate form; particulate ion-] eachable silicate or aluminosilicate (ii); and metal salt (iii). When the latter is in powder form, it preferably has a degree of fineness such that it will pass through a 1 0 B.S. mesh sieve. It is also possible to supply or store the composition as a two-component pack, one of which pack components may comprise an aqueous medium; indeed it may simply comprise distilled water, optionally tinted. In many cases, however, it is found that mixing, and the physical properties of the resulting cement, are improved by providing the poly(carboxylic acid) or metal salt (iii) or complexing- agent, all as herein defined, as an aqueous solution which may suitably comprise a mixture as hereinabove defined of such constituents. Such aqueous solutions may contain from 20 to 65% by weight of the poly(carboxylic acid), '•.'here the metal salt (iii) is also included in that solution it must be free from any tendency to precipitate the poly(carboxylic acid) (i) . It may instead be included in admixture the particulate ion-leachable- _V_E _ silicate or aluminosilicate (ii) or indeed in both. It may be found convenient to include the metal salt (iii) in an aqueous solution while the poly(carboxylic acid) or precursor thereof (i) is in dry admixture with the particulate ion- leachable silicate or aluminosilicate (ii). Furthermore, any chelating agent present may be included either with the particulate ion-leachable silicate or aluminosilicate (ii) or in an aqueous phase.In addition, hardenable compositions according to the present invention may comprise an amount of filler, suitably from 10 to 65%, preferably 25 to 50%, by weight of filler of the total weight of the components. Such materials include sand, talc, and fibrous materials such as asbestos and nylon. Inclusion of an inert filler is found to minimise any problem of contraction and cracking of the hardened composition which may occur.Furthermore, where the hardened composition is intended for use in a low humidity environment it is found beneficial to incorporate, in the hardenable composition, an amount, suitably from to 70% by weight, of an emulsion of a substantially water-insoluble polymer, particularly a polymer comprising carboxyl groups capable of participating in the setting reaction to form the hardened composition. Examples of such water-insoluble polymers include copolymers of unsaturated aliphatic carboxylic acids, such as acrylic acid, methacrylic acid or itaconic acid, with unsaturated aliphatic esters, such as methyl methacrylate, ethyl methacrylate and ethyl acrylate.The hardenable compositions of this invention may be used as dental cements and have many applications in dentistry including use as filling materials for restoring teeth and for cementing inlays and crowns into place in the tooth; as luting compositions to provide a base and/or lining in a tooth cavity or a temporary fixing for the bonds of orthodontic appliances to the teeth; and as compositions for sealing root canals after endodontic treatment. TheyI may also be formed as hardenable sheet materials, for example by depositing the components, optionally in intimate admixture, upon a flexible support web which may be woven, laid down as a non-woven fabric, cast or extruded. Preferably such a flexible support web may be a cotton bandage fabric, for example of leno weave. Such sheet materials have important surgical applications such as splinting materials. They may also be used in forestry (to repair and support damaged branches) and as modelling materials. The hardenable compositions may also be used in the building industry as surface coatings, flooring materials, speciality cements, including groutings, panellings, shuttering and a hesives. They may also be used to seal exposed and hazardous asbestos surfaces and claddings as disclosed in our copending U.K. Patent Application No. 1834/78. The hardened compositions also provide a binder for foundry sand which has the merit that while used in small amounts it provides good green strength for the bound sand yet, after investment, gives a readily friable, recyclable foundry sand. The hardened compositions are also useful as moulds for ceramic articles. Stannous fluoride containing compositions are found to be radio-opaque, a property useful in dentistry.The following Examples illustrate the invention; in these Examples the composition of the fusion mixture of the glasses by weight is as shown in Table 1.BUR£O PI TABLE 1COMPOSITION OF GLASS FUSTON MIXTURESGlass SiO Al O CaC0 MgCO Na„AIF, CaF„ AIF. A1P0, Ca (PO, )2 3 3 3 3 6 2 4 *± _1 175 100 30 207 32 60 2 175 100 60 2203 100 100 200 4 160 100 l4θ _5 120 102 300 I 6 360 102 2007 180 102 100240 68 2009 60 102 200 10 300 102 365 11 180 102 183- 14 - EXAMPLE 1 This Example illustrates the effect of various salts on the setting time of the slow-setting glass 8. The results are shown in Table 2.SETTING TIMES (MIN) TABLE 2 A_ B_Aluminium fluoride 145 25Barium chloride 330 60Barium fluor de > 420 23Bismuth phosphate > 420 60 Cadmium sulphate 240 15 Calcium chloride > 420 > 420 Copper chloride > 420 270Magnesium fluoride l o 20 Mercuric chloride 310 53 Stannous chloride 420 6Stannous fluoride 128 12 Silver difluoride 22 11 Silver nitrate 17 18 Sodium fluoride 420 y 420 Zinc chloride 420 47 Table 2 (continued) B Zinc fluoride 250 15 Zirconium oxychloride 72 10 Metal additive > 420 > 420With no additives the setting time was greater than 420 mins. A. no tartaric acid in liquid; 10% of metal salt in powder. B_ 5% tartaric acid in liquid; 10% of metal salt in powder.EXAMPLE 2 This Example illustrates the effect of stannous fluoride on the compressive strength of certain glasses. Curing of the o hardened composition was effected at 37 c for 24 hours in eachI case.Cylinders of cement (12mm long and 6mm in diameter) were o prepared in sealed moulds cured at 37 C for 1 hour and then placed either into water or liquid paraffin, at 37 C, for a further 23 hours. The results are shown in Table 3-TABLE 3 CEMENT STRENGTH (N/mm2) Glass A B C D1 165 97 153 953 3.3* 69* 16 79*7 31* 90* 33* 96*11 31* 51* 48* 69**In these cases curing was effected in liquid paraffin. A. No additives.B; No tartaric acid in liquid: 1% SnF in powder. C. No tartaric acid in liquid- 10% SnF in powder. Ds 5% tartaric acid in liquids no SnF in powder. El 5% tartaric acid in liquid: 10% SnF in powder.EXAMPLE 3 This Example illustrates the effect of stannous fluoride on the working time and setting rate (relative to glass 1) on certain glasses. Cement pastes were prepared at 23 C and an oscillating1 rheometer was employed to determine their working time and o 2 setting rate at 23 C following a set procedure1S.C.Bovis, E.Harrington and H.J.Wilson (1971) Br. dent J. π. 352.2A.D.Wilson, S.Cri.=p and A.J.Ferner (1976) J, dent Res,The results are shown in Table 4.BUKEAtf A TABLE 4WORKING TIMES AND SETTING RATES (at 23 C)-JIA: No additives B: No tartaric acid in liquid; 1% SnF in powder C: No tartaric acid in liquid; 10% SnF in powderTABLE 4WORKING TIMES AND SETTING RATES (at 23 C)fr03As No additives B: No tartaric acid in liquid; 1% SnF in powder C: No tartaric acid in liquid? 10% SnF in powderEXAMPLE 4 This Example illustrates the effect of stannous fluoride on the relative setting rate of a greater variety of glasses. A ranking order for the effect of additives , is given for each glass.The results are shown in Table 5.TABLE 5 Glass A B C D2 4 2 3 13 4 2 3 14 4 2 3 15 2 1 3-5 3 - 5 7 4 3 2 14 3 2 19 4 3 2 1 0 4 3 2 1 1 4 3 2 14 represents the longest, 1 the shortest, setting time.A: No additives.B: No tartaric acid in liquid, SnF in power .C: 5% tartaric acid in liquid.D: 5% tartaric acid in liquid, SnF in powder. uREAt/ C.v.Pl EXAMPLE 5 This Example illustrates the effect of stannous fluoride on the setting time of glasses and minerals at 37 C.Setting of cement pastes (at 37 C) were determined at 37 C using the method disclosed in International Standards Organisation Recommendation 1S0/R 1565•The results are shown in Table 6. TABLE 6SETTING TIMESi OF VARIOUS CEMENT COMPOSITIONSGlass orMineral SETTING TIME (MIN) 1 at 37°cA B C D E F1 7-5 4.75 4 42 47 22 24 8.253 > 240 74 120 294 44 8.25 13.25 55 3 2. 5 3-25 3. 256 > i860 > i860 > 1800 14107 34 14.5 9 5-258 > 240 128 38.25 11.759 7-5 7 4.25 3- 75 0 34.75 25- 75 8.25 6. 5 1 29 19. 5 10.75 7- 25 2 > ■3180Muscovite 9<*75 8.75 5.5 5Chlorite 50 34.75 45 49Dioptase 37 13 23 76Scolecite 9«5 8.75 4.5 4.25 TABLE 6 (continued)DRiebeckite 397 > 450 125 > 1260 Nontronite 57-25 38.75 24.25 20.75A: No additivesB: No tartaric acid in liquid, 1% SnF in powder-_5C: No tartaric acid in liquid, 10% SnF in powderD: 5% tartaric acid in liquid, No SnF in powderE: 5% tartaric acid in liquid, 1% SnF in powderF: 5% tartaric acid in liquid, 10% SnF in powder.EXAMPLE 6 This Example illustrates the effect of various salts on the hydrolytic stability of a selection of glasses.Cylinders of cement (12mm long and 6mm in diameter) were prepared in sealed moulds and stored at 37 C for either 1 hour or 24 hours before immersing in water. Hydrolytic stability was ascertained visually and a cement was considered to be hydrolyti- callyunstable if visible signs of disintegration were observed. Strength measurements were made 48 hours after cement preparation.The results are shown in Tables 7 and 8. TABLE 7 EFFECTS ON ADDITIVES ON THE HYDROLYTIC STABILITY AND COMPRESSIVE STRENGTH OF OXIDE GLASSES >~0TABLE 7 (continued) EFFECTS ON ADDITIVES ON THE HYDROLYTIC STABILITY AND COMPRESSIVE STRENGTH OF OXIDE GLASSESGlass Control AIF AIF + T MgF, MjF2 t*. T ShF, SnF„ + T ZnF111% additive1 hr. hydrolytic stability24 hr. hydrolytic stability S S U S ro2 day CS N/mm2 7-5 30 8.4 31 43 15-75S - StableU - UnstableT - Tartaric acid added to liquidTABLE 7 EFFECTS ON ADDITIVES ON THE HYDROLYTIC STABILITY AND COMPRESSIVE STRENGTH OF OXIDE GLASSEStTABLE EFFECTS ON ADDITITIVES ON THE HYDROLYTIC STABILITY AND COMPRESSIVE STRENGTH OF OXIDE GLASSESS - StableU - UnstableT - Tartaric acid added to liquidTABLE 8 THE EFFECT OF ADDITIVES ON THE HYDROLYTIC STABILITY AND COMPRESSIVE STRENGTH OF OXIDE GLASSES REPRESENTED IN RANKING ORDERt - - indicates a decrease in control properties0 represents no improvement in control propertiesLowest number represents the least improvement in control properties highest number the greater improvement.TABLE 8 (continued) THE EFFECT OF ADDITIVES ON THE HYDROLYTIC STABILITY AND COMPRESSIVE STRENGTH OF OXIDE GLASSES REPRESENTED IN RANKING ORDERCO CO - indicates a decrease in control properties0 represents no improvement in control propertiesLowest number repi-esents the least improvement in control properties highest number the greater improvement. | CLAIMS1. A hardenable composition which comprises (i) a poly(carboxylic acid) or precursor thereof (as herein defined); (ii) a particulate ion-leachable silicate or aluminosilicate reactable with (i) in the presence of water to set to a hardened compsition; and (iii) a metal salt which accelerates the setting of the composition.2. A hardenable composition according to Claim 1 wherein (iii) comprises a silver (i) salt or a barium salt.3. A hardenable composition according to Claim 2 wherein (iii) comprises silver nitrate, barium chloride or barium fluoride. 4. A hardenable composition according to Claim 1 wherein (iii) comprises a multivalent metal salt the cation of which either has an ionic potential above 2.1 or is capable of forming completes. 5- A hardenable composition according to Claim 1 wherein (iii) comprises a multivalent metal salt the cation of which has a o , standard electrode potential E less than 2.6 volts. ox6. A hardenable composition according to Claim wherein (iii) comprises a salt of aluminium, cadmium, magnesium, mercury (II), silver (II), or zirconium.7. A hardenable composition according to Claim 6 wherein (iii) comprises a salt of aluminium, magnesium, silver (II) or zirconium.8. A hardenable composition according to Claim 1 wherein (iii) comprises a fluoride. 9. A hardenable composition according to Claim 8 wherein (iii) comprises aluminium fluoride, magnesium fluoride, stannous fluoride, silver difluoride or zinc fluoride.10. A hardenable composition according to any of the preceding claims wherein (iii) is soluble in an aqueous solution of (i),11. A hardenable composition according to any preceding claim which further comprises a complexing agent soluble in an aqueous solution of (i).12. A hardenable composition according to Claim 11 wherein the complexing agent comprises a fluoride ligand.'13. A hardenable composition according to Claim 11 or 12 wherein the complexing agent comprises a chelating agent. 14. A hardenable composition according to Claim 13 wherein the chelating agent comprises a plurality of carboxyl groups. 15- A hardenable composition according to Claim l4 wherein the chelating agent comprises aconitic, itaconic, mal-eic, mellitic or tricarballic acid. l6. A hardenable composition according to Claim 13 wherein the chelating agent also comprises at least one hydroxyl group. 17. A hardenable composition according to Claim 16 wherein the chelating agent comprises citric, malic or tartaric acid. l8. A hardenable composition according to Claim 13 wherein the chelating agent comprises a multivalent metal. chelate. 19- A hardenable composition according to Claim l8 wherein the chelating agent comprises a beta-diketone metal chelate or an EDTA chelate. - 32 - 27- A mixture suitable for use in preparing a hardenable composition according to any of Claims 1 to 25 which comprises a metal salt (iii) as defined in any of Claims 1 to 10 and 21 and both (a) and (b) as defined in Claim 26. 28. An aqueous mixture according to Claim 26 or 27-29- A hardenable composition according to any of Claims 1 to 25 comprising a dry mixture of the poly(carboxylic acid) or precursor thereof (i) in particulate form; particulate ion- leachable silicate or aluminosilicate (ii); and metal salt (iii). 30. A hardenable composition according to any of Claims 1 to 25 or 29 supplied as a two-component pack, one of which components may comprise an aqueous medium.31. A hardenable composition according to Claim 30 wherein the aqueous medium comprises a complexing agent as defined in any of Claims 11 to 20 or a metal salt as defined in any of Claims 1 to 10 and 21 or a poly(carboxylic acid) or precursor thereof as defined in Claim 1 or 25«32. A hardenable composition according to Claim 3° wherein the aqueous mixture is defined in Claim 28. 3 ' hardenable composition according to any of Claims 1 to 25 or 29 supplied as a sheet material.34. A process for preparing a poly(carboxylate) cement which comprises mixing water, (i) a poly(carboxylic acid) or precursor thereof, as defined in Claim 1 or 25 and (ii) a particulate ion-leachable silicate or aluminosilicate as defined in Claims 1 or 24 with (iii) a metal salt as defined in Claims 1 to 10 and 21. - 31 -20. A hardenable composition according to Claim 18 wherein the multivalent metal is the same as that in (iii).21. A hardenable composition according to any of Claims 13 to 20 wherein (iii) comprises a multivalent metal fluoride or a multivalent metal chloride the cation of which has a standard o - electrode potential E less than 2.6 volts. ox22. A hardenable composition according to any preceding claim wherein (iii) is present in an amount of up to 15% by weight, based on the weight of (i). 23. A hardenable composition according to any of Claims 13 to 22 wherein the weight ratio of (iii) to the chelating agent is from 15°.l to 1-15.24. A hardenable composition according to any preceding claim wherein (ii) comprises a (fluor)aluminosilicate glass powder. 25- A hardenable composition according to any preceding claim wherein (i) comprises an acrylic acid homopolymer or copolymer of acrylic acid with one or more of aconitic, fumaric, itaconic, maleic, mesaconic, methacrylic, muconic, or tiglic acid. 26. A mixture suitable for use in preparing a hardenable composition according to any preceding claim which comprises a metal salt (iii) as defined in any of Claims 1 to 10 and 21; and (a) a complexing agent as defined in any of Claims 11 to 20 or (b) a poly(carboxylic acid) or precursor thereof (i) as defined in Claim 1 or 25- 35. A process according to Claim 34 wherein the mixture further comprises a complexing agent defined in any of Claims 11 to 20.36. A hardened poly(carboxylate) cement prepared by the process of Claims 34 or 35.■_!?!•_-, •j v.ipo -' | CRISP S; NAT RES DEV; WILSON A; NAT RES DEV CORP | CRISP S; WILSON A |
WO-1979000522-A1 | 1,979,000,522 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | B62M9 | F16H11, F16H55, F16H9 | B62M9, F16H9 | B62M 9/08, F16H 9/10 | DRIVE SYSTEM | A variable speed pulley and belt drive system (10) for use with bicycles, and for industrial drives, and the like. The system utilizes a variable diameter pulley and belt take-up member (22) to compensate for changes in the pulley diameter, said belt take-up member (22) preferably comprising a somewhat similar variable diameter pulley. Arcuate belt engaging segments (30) are provided between a fixed sideplate (26) and a movable sideplate (27) of the variable diameter pulley and pins (31) are provided at one side of each of the arcuate belt engaging segments to guide one side of each segment (30) in curved guide slots (29) in the fixed sideplate (26) and the other side of each arcuate belt engaging segment in straight slots (33) provided in the movable sideplate (27). Springs (37) interconnecting the fixed (26) and movable (27) sideplates are used to return the movable sideplate (27) in response to tension on the belt (25) passing around the arcuate belt engaging member (30). | DESCRIPTION OF THE INVENTION10. Technical FieldThis invention relates to variable speed, automatic drive systems utilizing pulleys and belts. Background ArtIn the past there have been a great many variable15. speed drive systems developed for use with bicycles and the like. Some of the most common systems utilize sprockets of different sizes and shift a chain from sprocket to sproc¬ ket in order to obtain difierent drive ratios. Such systems do not provide for an infinitely variable drive and have20. proven difficult to maintain in service, since the appar¬ atus used to change from sprocket to sprocket must be maintained in rather precise alignment to ef ect the shift¬ ing, and since such shifting apparatus is easily damaged or knocked out of alignment. Other systems have been developed25. for changing an effective sprocket diameter around which a chain is entrained. Such systems, are shown for exampl in U.S. Patent No. 's 3,800,613 and 3,938,403. The systems dis¬ closed in such patents involve means for moving small sproc¬ ket wheels that are adapted to be engaged with a chain. In30. these disclosed systems, controlled means are provided to allow an operator to manually set the drive ration, within the range permitted by the design of the apparatus used. In U.S. Patent No. 3,769,849, there is disclosed a vari¬ able speed belt drive for use with bicycles and the like. 5_ The drive system disclosed in this patent provides for an infinite variety of ratios between high speed and low speed extremes and to achieve such ratios uses taperedBAβORIGINAL li belts, variable pulleys, and level- means to apply tens to change the diameter of a variable control pulley. None of the patents or prior art w th whicli I am familiar disclose a variable pulley having a belt enga5. ing surface that will engage the undersurfaces of a be and wherein the belt engaging surface of the pulley is movable to change the overall diameter oi the belt eng ing portion around which the belt is entrained.While the drive systems shown in the prior art app10. to be useful and many will accompl i h the desired obje tive of changing the torque requi red of the pul ley and belt system, they are not entirely suitable since they generally require a large number of components and are difficult to construct, or they do not provide for ade15. qυate pulley surface-belt engagement to effect a conti uous non-slip drive system.Disclosure of InventionPrincipal objects of the present invention are to20. provide an automatic pulley-bolt drive system that i.s reliable in operation and that requires Little mainten ance for long term, t ouble free operation.Principal features of the invention include a belt engaging pulley having a fixed sidewall and a spaceu25. apart able sidewall. Arcuate belt engaging sector.-., are provided between the sidewalls and are mounted to be guided in curved slots pi-uvi riod therefore* in the fixed sidewall and in straight slots provided therefor in the movable sidewall.30. Springs having one end anchored to the fixed side¬ wall and the other end anchored to the movable sidewal are adapted to re-position xhe movable sidewall in re¬ spect to the fixed sidewall after the movable sidewall has rotated with respect to the fixed sidewall in re-35. sponse o tension changes in a belt passing over the arcuate belt engaging sectors and between the side allAdditional objects and features of the Invention will becom apparent from the following derailed d - cription taken together with the accompany ng dravings and cl ims. 1 i 4 prefered as a belt take-up means i.u lake up slack in the belt 25 interconnecting the pull'-ys 22 and 24, other b**-lt take-up means can be used.5. As shown best in F gs. 2 and , he variabl 1 pullov 22 includes the sideplate 26 that is iixoα to and movable with the crank arm 23. Another sideplate 27 is journaled on the crank arm 23 and is spaced from the fi ed sideplate by a bushing 28. The ixed sideplate 26 has a series of10. paired curved slots 29 formed the ein. The .--.lots 29 ru of identical configuration, with one end of each slot terminating on a circle spaced inwardly of and concentric with the outer edge of the outside edge of the sideplate 26. The other end of each slot 29 is similarly terminated15. on a smaller concentric circle such that each slot 29 will be curved from the end on the rger concentric circle to the end on the smaller concentric circle in the direction opposite to the rotation of the sideplate 26 during driving operation of the crank 23.20, An arcuate, belt engaging sector 30 extends across each pair of slots 29 and a pin 31 projects from e ch end oi each arcuate sector 30 through an ad acent slot 29 such that the head of the pin is on the outside of the fixed sideplate and the belt engaging seder 30 is between the q . fixed and movable sideplates.The slots 33. each have an outer end on a circle that is concentric with the outer edge o the movable sideplate27 and an inner end that is on a concentric circle spaced closer to the crank assembly 23 and opposite to the smaller30. concentric circle on which the ends of slots 29 on the fixed sideplate are positioned.The fixed sideplate 26 is ati ached by screws 3-i to the bushing 28 that separates the sideplates 26 and 27. 3ush;ng28 has an attachment plate 35 nu'i.vd the e and the.->q attachment plate is then Jixod to * he crank asserbly 23. The movable sidep ate 27 has a up o t place 36 that fits rotatably around the crar.k assembly hoυsirg.Λ nυmi --r of coil springs 37 luh have one end fixed to the support plate by a pin 38 and an opposite end aifix-dBABORIGINAL 3 -1 *. brief Description of D awingIn the drawings:Fig. 1 is a top plan view of the drive system of the invention shown mounted on a bicycle frame and with the 5. frame and the pedal crunk as embly of the* bi^yel , shown ragmen rily ;Fig. 2, a side elevation vi t.-w of the drive system of the invention as shown in Fig. 1, with additional parts removed for clarity; 10. Fig. 3. an enlarged sectional view taken on the line 3-3 of Fig. 2;Fig. 4, an enlarged sectional view taken on the l .ne 4-4 of Fig. 2; andFig. 5, is an enlarged pictorial view of an arcuate lύ*. belt engaging sector uf the invention.Best Mode of Carrying out the Invent!on Referring now to the drawings:In the illustrated preferred embodiment, the drive20. system of the invention, shown generally a 10, is ill¬ ustrated as being used with a bicycle shown generally at 11. As shown, the bicycle, which is shown only frag- mentarily, is represented by bifurcated rear wheel sup¬ port members 12 and 13 that extend rearwardly from n25. crank housing 14 to which are attached upstanding tub¬ ular frame members 15 and 16. A rear hub 17, having spokes 18 emenating therefrom as part of a wheel (th spokes and wheel being shown fragruontari ly) is mount i in conventional fashion to frame members 12 and 13 by30. lock nuts 20 and 21.The drive assembly 10 of the invention includes large variable speed pulley 22 attached to and rotat ble with the usual crank arm 23 of the bicycle pedal assembl The crank arm 23 is shown fragrhc-ntariiy, but it is to be35 _ understood that such crank arm is of conventional config¬ uration and will have pedals (not shown) thr-reon through which the crank arm is rotated. A smaller variable speed pulley 24 of the invention is fixed to the hub 17 and rotates with the wheel of the bicycle. As will be furthe -.;xplallied, while the smaller variable speed pulley is to the bushing 28 by a pin 39. Knch c.oi 1 spring 37 ex¬ tends from its pin 38 outwardly from the crank assembly housing in the direction of rotation of the pulley 22. 5. The springs 37, thus normally bias the support plate 36 and the attached movable sideplate 27 such that the pins31 are in the outermost ends of slots 29 and the pins32 are in the outermost ends of the slots 33.Variable speed pulley 24 serves to compensate for10. slack in the belt 25, as will bo further explained. The pulley 24 includes a fixed sideplate 40 and a spaced apart movable sideplate 41. As with the fixed sideplate 26, the fixed sideplate 40 has pa rs of curved slots 42 formed therein. Each of the slots 42 has an outer end on15. a circle that is concentric w th the outer edge of the fixed sideplate 40 and an inner end lying on a concentric circle of the hub 17, to which the sideplate 40 is affixed.Also, like the movable sideplate 27, the movable side¬ p ate 41 has pairs of strai ht slots 43 formed therein.20. The outer end of each slot 43 lies on a circle concentric with the outer edge of the movable sideplate 41 and spaced inwardly from the outer edge of the oveable plate. The inner end of each slot 43 lies on a smaller concentric- circle closer to the hub 17 and preferably opposite to25. the inner ends of slots 42. Arcuate belt engaging sectors 45 are provided between the fixed sideplate 40 and the movable sideplate 41. Each arcuate belt engaging sector 45 has pins 46 projecting from one side thereof at oppo¬ site ends with pins extending through a pair of the slots30. 42 such that heads of the pins are outside of the affixed sideplate and the arcuate belt engaging sectors are inside the fixed sideplate. Similarly, pins 47 extend from the opposite sides of the arcuate belt engaging sectors at opposite ends thereof and through the pai s of slots 433 . such that the heads of the pins 47 are outside the mov¬ able sideplate 41 while the arcuate sectors are inside the plate.In the operation of the drive system 10, the crank assembly 23 is turned in conventional fashion by an oper¬ ator pushing on pedals (not shown), attached to the crankBAB 1. assembly. With th * drive assembly in the condition shown, wherein the arcuate belt engaging sectors 30 are at the outermost ends of the slots 29 and 33, and wherein the arcuate belt engaging sectors 45 of the variable pulley5. 24 are positioned at the innermost ends of the slots 42 and 43 the highest drive ration between the crank assemb and the wheel 19 is obtained. Rotation of the variable pulley 22 using the crank assembly 23 will drive the ar¬ cuate belt engaging sectors 45 and the hub 17 and wheel10. 19 attached thereto. As greater resistance develops to turning of the wheel 19, as for example when a user thereof is attempting to pedal the bicycle 11 up a hill, the resistance is transmitted through the upper run of the belt 25 to the arcuate belt engaging sectors 30 and15. 45 and such resistance will pull the arcuate belt engag¬ ing sectors 30 towards the inner ends of their slots 29 and 33, against the biasing effect *>f springs 37 and at the same time will pull the arcuate belt engaging sec¬ tors 45 outwardly with respect to their slots 42 and 43.20. Thus, as resistance to turning of the wheel 19 is in¬ creased, the effective diameter o i' the driving pulley, i.e. variable pulley 22 is decreased while the effected diameter of the driven pulley, i .e. variable pulley 24 is increased, to thereby change the drive ratio between25. the crank assembly 23 and the wheel 19.The arcuate belt engaging sectors 30 and 45 are best shown in Fig. 5. As shown, each sector includes an ar- cuately shaped body portion 60 and sidewalls 61 and 62 projecting upwardly therefrom. The inner surfaces of30. the sidewalls 61 and 62 are inclined to match the angula side surfaces of the conventional V-belt 25. The upper surface of b*κϊy 60 and the inner surfaces of sidewa1is 6 and 62 are each made rough, for example by use of cross- scoring., as shown, to provide for a better fractional en35. gagement with the belt 25.While in the err.b-'di ent .shown, the variable pulley 22 is a drive pulley ;- r. d is shown larger than variable pulley 24, which is a driven pulley, it will be apparent that -such relative sizes are -.-ntirely a natter of choice and that each pul ey m y li made larger or s::.?ll r, as 1- desired. It will also be apparent that on variable pulley can be used wi h a pulley of fixed diameter and that conventional belt adjusters may be used to keep the belt taut as the diameter of the variable pulle¬ s' used changes.It should be further apparent that the: strength of the springs will determine the degree of resistance re¬ quired in the belt 25 to cause movement of the belt en¬ gaging sprocket sectors of the variable pulley or pulleys 10. used and that the springs may bo varied, as required to achieve desired shifting characteri tics.Industrial ApplicabilityThe present invention is useful as a means of vary¬15, ing the drive ratios of bicycles and other vehicles and for use as an industrial drive for machines and the like.Although a preferred form oi' h.y invention has herein been disclosed, it is to be understood that the* present disclosure is by way of example and that variations rc-20, possible without departing from the subject matter coming within the scope of the following cl ims, which subject matter I regard as mv invention.25,30,35.BAB | 1 . TII CLAI MSI Cl aim :1. A drive system comprising a pair of pulleys; 5. a belt drivingly engaged with said pulleys; at least one of said pulleys being a variable sp_*ed pulley and including a sideplate fixed with respect to a rotatable shaft; a movable sideplate spaced from said fixed sideplat 10. and rotatable around the rotatable shaft; pairs of curved slots formed in the fixed sideplate, said curved slots each having one outer end spaced inwardly from an outer edge of the fixed sideplate and on a circle concentric with the 15. outer edge and its other inner end on a smaller concentric circle, whereby said slots extend outwardly and in a direction of rotation of the4 sidewall ; pairs of straight slots formed in the movable side-20. plate, each said straight slots having one oute end on a circle concentric with the cuter edge of the movable sideplate and its other inner end on a smaller concentric circle; and arcuate belt engaging sectors between said fixed ;.n25. movable sidewalls. each said belt engaging se t means at opposite ends of one side there for guiding said belt engaging sector in a pair of said curved slots and means at opposite ends of an opposite s de thereof for guiding sa d30. belt engaging sector in a pair of said straight slots .2. A drive system as in Claim 1 , wherein at least one of the variable speed pulleys includes35. means resilientiy biasing the movable si deplete wit respect to the fixed sideplate s.uch that the be engaging sectors are guided to the outer ends o the slots.BAB OR1GHNA 1. A dr ve system as n Claim 2, wherein the means resilientiy biasing t e movable side-plate with .respect to the fixed sideplate comprises springs connected between the said sideplates.5.A drive system as in Claim 1, wherein the belt engaging sectors have an arcuate belt engag¬ ing surface and upstanding sidewalls adapted to engage the belt.10,A drive system as in Claim 4, wherein the belt engaging surface and the sidewalls are each provided with a rough surface to engage the belt15 A drive system as in Claim 5. wherein both pulleys are variable speed pulleys, each includ¬ ing a fixed sideplate; a movable sideplate spaced from said fixed side¬ plate; pairs of curved slots formed in the xed20 sideplate; said curv?d slots each having an outer end spaced inwardly from an outer edge of the fixed sideplate and on a circle con¬ centric with the outer edge and its other inner end on a smaller concentric circle, where¬25 by said slots extend outwardly and in a direc¬ tion of rotation of the sideplate; pairs of straight slots formed in the movable side¬ plate, each said straight slot having one outer end on a circle concentric with the outer edge of30, the movable sideplate and its other inner end on a smaller concentric circle; and arcuate belt engaging sectors between said fixed and movable sidewalls, each said belt engaging sector having means at opposite end.-, of one35 side thereof for guiding said belt engaging sector in a pair of said curved slots and means at opposite ends of an opposite side thereof for guiding said belt engaging sec¬ tor in a pair of said straight slots. 1. 7. A drive .system as in Claim 6. wherein at least, one; [ the variable speed pul leys includes means resilientiy biasing the movable sideplate with respect to the fixed sideplate such that5. the belt engaging sectors r gui ed to the outer ends of the slots.8. A drive system as in Clain 7, wherein the means resilientiy biasing the movable sideplate 10. with respect to the fixed sideplate comprises springs connected between the said sideplates.9. A variable pulley for use with belt drive systems comprising a sideplate adapted te) be fixed to a15. rotatable shait; a movable sideplate spaced from said fixed sideplate and rotatable around the rot t jjle shaft; pairs of curved slots formed in the fixed sideplate, said curved slots each having one outer end space20. inwardly from an outer edgf> of the ϊixed sideplat and on a circle concentric, with the outer edge an its other inner end on a smaller concentric circl whereby said slots extend outwardly and in a di ¬ ection or rotation of the sidewall;25. pairs of straight slots forme/d in the movable side¬ plate, each said straight slots having one outer end on a circle concentric wi h the outer edge of the movable sideplate and its other inner end on a smaller concentric circle; and30. arcuate belt engaging sectors between said fixed and movable sidewalls, each said belt engaging sector having means at opposite ends oJ one side thereof for guiding said belt engaging sector in a pair o said curved slots and means at opposite ends of a35 _ opposite side thereof for guiding said belt engag ing sector in a pair of said straight slots.10. A variable pulley as in Claim 9, further including means resilientiy biasing tin* movable sideplate with respect to the fixed sideplate such that the be t2A 1. engaging sectors are guided to the outer ends of the slots.11. A variable pulley as in Claim 10, wherein5. the means resilientiy biasing the movable sideplate with respect to the fixed sideplate comprises springs connected between the said sideplates.12. A variable pulley as in Claim 11, wherein10. the belt engaging sectors have an arcuate belt en¬ gaging surface and upstanding sidewalls adapted to engage the belt.13. A* ariable pulley as in Claim 12, wherein15. the belt engaging surface and the sidewalls are each provided with a rough surface* to engage the belt202530,35,BURt,T - | WILLIAMS R | WILLIAMS R |
WO-1979000524-A1 | 1,979,000,524 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | H03K5 | H03K5, H04N5 | H03H11, H03K3, H03K5, H04N5 | H03K 3/78, H03K 5/15D2 | DIGITAL SIGNAL PHASE SHIFTING SYSTEM | Digitally coded time signals are employed to control the generation of cyclic system output signals. Time signals are fed to the inputs of first and second output signal generators (14) and (15) respectively. A setting device (17), adjustable by the user, conditions the second output signal generator to shift the phase of a group of second generator output signals relative to the first output generator signals. Alternate constructions (15) and (16) of the second output signal generator provide capabilities of phase shifting either groups of pulses or a single pulse. | DIGITAL SIGNAL PHASE SHIFTING SYSTEM Technical FieldThe present invention relates to systems for producing multiple cyclic output signals having predetermined time relations to each other and more particularly to such systems wherein the times of occurrence of the signals during the cycles, i.e., their phase relationships, can be selectively shifted.One typical environment for selective phase shifting of multiple signal pulses is in the production of the image from a single television camera on multiple, coordinated television displays so that each display screen exhibits a portion of the camera image.In such systems the camera operation is generally controlled by two or more conmand signals, usually called drive pulses, which are cyclic, may have different durations and occur at different respective times in the cycle interval. Likewise each display may be controlled by multiple cyclic drive pulses which have different durations and occur at different respective times in the cycle.Because a predetermined part of the camera image is depicted by each display, operation of each display must be closely and accurately coordinated with the other displays and with the camera itself. As an example of the criticality of the coordination required, in many circumstances the camera is located remotely from the displays and the very slight delay attendant the passage of electrical signals through transmission cables to the displays is sufficiently long to adversely affect the image quality. This delay in transmission through the cable is called propagation delay. In order to accoππt late the display operation to the camera,- the camera operating drive pulses must be coordinated with display drive pulses in accordance with the extent of propa¬ gation delay being presently experienced. This requires that the system user have the ability to change the phase relationship between the camera and display drive pulses. As noted, there nay be a significant number of display and camera drive pulses and consequently each display drive pulse must be shifted in time relative to the appropriate camera drive pulses in order to avoid problems resulting from the propagation delay.If multiple cameras are used and the propagation delay from one camera is different from that of another, the display drive pulses should be simultaneously, and virtually instantaneously, adjusted if coherent successive images from different cameras are to be displayed.In addition to shifting the phase of multiple display drive pulses relative to a given camera drive pulse it is sometimes necessary, or at least desirable, to simultaneously alter the durations of the display drive pulses. This is done, for example, when the sweep frequency of the display units is to be altered. Another situation in which display unit drive signals must be altered with speed and accuracy is where a television camera image which is substantially smaller than the screen area of the display unit, or units, moves around relative to the display unit, or units.Background ArtTechniques for advancing or delaying cyclical signal pulses relative to each other have been used in the past. Analog phase shifters have been proposed for use in advancing or delaying signal pulses relative to each other. In one such proposal a first drive pulse initiated operation of a voltage ramp generator whose output was connected to the input pf an analog comparator. The other coπparator input was connected to a reference voltage so that when the ramp generator output equaled the reference voltage the comparator changed state thereby creating an output signal. The reference level was adjustable to alter the extent of delay of the comparator output. The components of analog systems were accurate and stable only over narrow operating condition ranges and therefore the extent of the advance or delay was limited by the quality of the system components. The components also tended to pick up electrical noise which affected the extent of the delay unsatisfactorily. Thirdly it was found that the ramp generators cycled at frequencies faich were too low for some applications. Many of the shortcomings of the analog systems were found to be avoidable by the use of digital electronic systems. One such digital system is disclosed by U. S. patent No. 3,833,854 issued to Robert W. Schonover on September 3, 1974. The Schonover patent discloses a clock driven counter comprising a number of flip-flops connected to form an asynchronous counter whose out¬ puts are connected to an AND gate for controlling operation of a second counter. Both counters are run by a comnon clock and loading the set inputs on the second counter results in a delay of the second counter's output relative to the first counter's output.Although the Schonover device overcomes some disadvantages of the analog phase shifting systems, that system did not enable simultaneous phase shifting of multiple signals. In seme circumstances when multiple display drive pulses were shifted relative to a camera drive pulse it has been possible to inadvertantly extend or shorten display drive pulse durations sufficiently that damage to deflection signal amplifier circuitry in the displays tended to occur. Moreover the Schonover circuitry was not sufficiently fast acting to enable phase shifting within a single cycle. The Schonover system limited to one per cycle the number of delayed or advanced pulses which could be accoirrnodated. If, for example, a three bit counter were used in the Schonover system a different output pulse drive from the second counter could be produced only after eight clock pulses were counted.Thus, while the Schonover approach avoided many of the serious shortcomings of analog puase shifters it did not provide a means for instantaneous or simultaneous phase shifting of cyclic drive pulses relative to each other. OMPI Disclosure of InventionThe present invention provides a new and improved system for shifting the phase of a group of cyclic output signals wherein phase shifting of the signals is accomplished simultaneously and substantially instantaneously.In accordance with a preferred euibodiiϊgrit of the invention a phase shifting system is provided wherein digitally coded time signals are employed to control the generation of cyclic system output signals. The time signals are fed to the inputs of first and second output signal generators. One output signal generator produces a group (at least two) of pulsating cyclic output signals which can be adjustably shifted relative to output signals produced by other signal generator.In accordance with another important feature of the invention a system is provided wherein system output pulses can be simultaneously phase shifted with the time elapsing between the pulses remaining unaltered during or by the phase shifting.These features make the use of systems embodying the invention particularly advantageous with multiple TV displays which depict a single coherent camera image on their screens. In such a system multiple system outputs are paired and fed to wave forming devices which produce desirably shaped TV camera and display drive signals. These drive signals may be in the form of digital pulses whose duration is determined by the time elapsing between system output signal pulses being fed to the wave forming device. Command signals for governing operation of at least one TV camera and all of the displays are thus produced. The group of display controlling command signals can be phase shifted instantaneously relative to the camera controlling coirmand signals without changing the duration of any cαrmand signals.This capability not only enables all of the displays to remain synchronized with camera operations when, for example, different cameras are used ca-using concxmnitant propagation delay changes, but also assures that command signal responsive circuits in the displays do not tend to be overloaded or otherwise damaged by undesirable abrupt changes in the coirmand signal durations.In a preferred embodiment of the invention the new system includes a timing signal generator for producing digitally coded timing signals, a first system output signal generator for producing at least one cyclic output signal in response to generation of a predetermined timing signal, a second system output signal generator for producing a group of system output signals, and an adjustable setting device connected to an input of the second system output signal generator for conditioning the second output signal generator to produce multiple output signals which bear a selected temporal relationship to the predetermined timing signal. By adjusting the setting device all of the second system output signals are simultaneously phase shifted relative to the first system output signals.O P In one form of the invention the second system output signal generator comprises at least a pair of digital signal responsive devices which are individually conditionable tp produce an output pulse in response to a predetermined digitally coded input signal. The signal generator also includes a digital signal processor connected between the digital signal responsive devices and the timing signal generator. The setting device conditions the signal processor to produce digitally coded output signals which either lead or lag the occurrence of corresponding timing signals. Changing the setting signal applied to the processor shifts the phase of all the output signals from the second system output generator. More particularly the system output signals are produced by digital comparators which can be set by the user to produce an output signal when a predetermined binary coded signal is input to them. The processor is preferably formed by a binary adder which is effective to algebraically add the timing signal to the setting arrangement signal and produce a binary coded output which is fed to the output signal producing comparators.In another output signal generator constructed according to the invention the second output signal generator comprises at least a pair of digital signal responsive devices which have inputs connected directly to the timing signal generator. The signal generator also includes-a digital signal processor having an output connected to the setting input of one of the digital signal responsive devices and first and second inputs. The setting arrangement is connected to the setting input of the other signal responsive device and to an input of the processor. The processor is preferably formed by a digital adder and its output is a digitally coded representation of the algebraic sum of its inputs. Changing the output of the setting device shifts the phase of all the second system output signals.Another important feature of the invention resides in the ability to perform phase shifting extremely quickly. The rate at which phase shifting can be accomplished is essentially limited to the rate at which the setting device can be operated to condition the signal generators. In this regard the setting device can be formed, for example, by an output of a digital computer which is sufficiently fast acting to enable multiple phase shifts during each cycle of operation of the system. This capability can have application in information fetching operations which have to be performed at high rates.Other features and advantages of the invention will become apparent frcm the following detailed description of a preferred embodiment and from the drawing which forms part of the specification and which schematically illustrates a system, for producing multiple cyclic output signals constructed according to the invention. Best Mode of Carrying Out the InventionA system 10 for producing multiple cyclic output signals_ O wherein groups of the output signals can be individually phase shifted is illustrated in the drawing. The system 10 comprises a tine signal generator 12 which produces digitally coded cyclic time signals; separate output signal generators 14, 15, and 16, respectively, which are independently responsive to the time signal generator 12 to produce respective groups of output signals; and setting devices 17, 18. for the signal generators 15, 16 respectively to enable the output signal from those generators to be phase shifted as desired by the system user. Phase shifting systems embodying the invention can be utilized in any environment where simultaneous phase shifting of groups of output signals is desirable or necessary and for the purpose of illustration and description the system 10 is disclosed in relation to a television system of the sort where three TV display -units are used to coherently display the iirage produced by a single TV camera. This kind of TV simulation is commonly used for simulating terrain etc. in vehicle simulators. Since the operations of the TV camera and displays are generally known, and do not form part of the invention, a simplified, schematic connection and relationship of the system 10 to the TV camera and displays (not illustrated but indicated by letters A, B and C) is described in order to facilitate understanding the invention.The time signal generator 12 provides a time reference for the system output generators -14-16 and comprises a conventional- digital clock 40 producing a continuous succession of individual clock pulses viiich are input to a digital counter 42 via an electrical interconnect 44. The digital clock may be constructed and arranged so that the frequency of its output signal can be controlled by the user. In a system of the character referred to the clock pulse frequency may typically be on the order of 7 megahertz.The digital counter 42 may be of any conventional or suitable construction having an input for receiving the clock pulses and an output 45 producing a digitally coded signal representative of the number of clock pulses input to the counter. The counter contains a number of output pin connections (not shown) and the counter circuitry operates the output pins between two voltage levels. The output pins are collectively capable of representing binary numbers. For the purpose of this description eight pin connections are assumed to be provided at the counter output so that the time signals output from the generator 12 are formed by binary coded signals representative counted clock pulses from zero to 255. When the 256th code pulse is counted the counter output is reset to zero and another cycle of clock counts is begun. The system 10, because of its response to the counter output signal is cyclically operated and the system cycle rate, assuming a clock frequency of 7 MHz, is about 30 KHz.The system output signal generator 14 produces at least one system output signal in response to the occurrences of predetermined timing signals generator outputs. The counter output 45 is connected via an electrical interconnect 52 to corresponding input pins (not shown) of the output signal generator 14. The preferred signal generator 14 is formed by suitable decoder components which produce system output signal pulses having a duration equal to one clock pulse in response to receipt and decoding of predetermined binary coded time signals on the interconnect 52 from the time signal generator. The signal pulses are output from the signal generator 14 on output lines 54, 56. The system output signal generator 14 produces each output pulse individually and is constructed and arranged to enable the user to alter the time elapsing between the output pulses by changing the time signals to which the decoder components respond.The system 10 is illustrated as used with a TV camera and displays and the system output signals from the signal generator 14 are fed to a wave forming device 57 which produces a horizontal drive pulse for the TV camera. The device 57 is illustrated as a conventional flip-flop which initiates an output camera drive pulse when a system output pulse is delivered to its setting input 58 and terminates the camera drive pulse when a system output pulse is delivered to its reset input 59. The TV camera drive pulse thus has a duration determined by the interval between the system output pulses from the generator 14 and the drive pulse duration is adjustable by the system user as noted above. Representations of the output pulses and the resultant TV camera horizontal drive pulse wave form are indicated in the drawings. Operation of a set-reset flip-flop is known within the art and details of its construction and operation are therefore not provided. It should be apparent that the flip-flop is not a necessity and that either or both output pulses from the generator 14 can be utilized to provide timing signals in an application of the system 10 other than a TV simulation environment referred to.The syste output signal generator 15 produces a group of system output signal pulses in response to operation of the timing signal generator 12. The illustrated signal generator 15 includes a pair of output signal pulse producing decoder units 62, 64, each producing two output pulses and a processor unit 66 for receiving and processing the timing signal generator output to provide a binary coded output to the decoder units 62, 64. The decoder units 62, 64 are identical and only the unit 64 is described. The decoder unit 64 comprises two digital comparators 72, 74 each having two inputs 75, 76 and one output 77. Each compares the digital signal input to its setting input 75 with the digital signal input from the processor unit to its input 76. When the comparator inputs are identical, that is, when the binary coded digital input signals represent the same number, a system output pulse is produced by the comparator. The system output pulses each have the sane duration as one clock pulse. The inputs 75, 76 of the comparators are each formed by eight separate pin connections (not illustrated) to enableOMP the comparators to decode binary coded signals representative of numbers from zero to 255.The set inputs of the comparators are each associated with a respective digital switch 80 which is manually set by the user to connect predetermined input pins to a suitable power supply and thereby control the time of production of the system output pulse produced by the comparator. The switches 80 can be of any known or suitable construction and are therefore schematically shewn and not described in detail. In the preferred embodiment of the invention the output signal generator 14, referred to above, is constructed identically to the decoder 64.The output signal pulses frαn the comparators 72, 74 are fed to respective set and reset terminals of a flip-flop 79 which in turn produces a horizontal drive pulse for controlling the horizontal sweep of an associated TV display. The flip-flops 79 are identical to the flip-flop 57 referred to above.The preferred processor unit 66 is formed by a digital adder having tvro inputs 82, 84 and an output 86 which is connected to both decoder units 62, 64. The adder inputs and output are each formed by eight pin connections to enable the adder to receive and transmit binary coded signals representative of numbers from zero to 255. The adder input 82 receives the binary signal output from the timing signal generator 12 via the interconnect 52. The adder may be of any suitable or'conventional construction and is not illustrated or described in detail. The output pulses frcm the system output signalO PI . 1PO A, generator 15 can be phase shifted relative to the signals output from the generator 14 simultaneously. To this end the setting device 17 is associated with the adder input 84 for supplying an adjustable binary coded signal to the adder. The adder is effective to algebraically sum the binary signals input to it and produce an output signal to the decoder units 62, 64 which is representative of the sum of the members represented by the adder input signals. The setting unit 17 is schematically illustrated as a manually operable setting switch connected between a suitable power supply and the adder input 84 and controlled by the user. The setting device can be of any desired construction.By changing the setting input to the adder the system output pulses are simultaneously phase shifted without altering their time relationships to each other. This assures that the drive pulses output from the flip-flops 79 can be phase shifted relative to the camera drive pulses simultaneously without changing the duration of either of the display drive pulses output from the flip-flops 79. The output signal generator 15 can be constructed using any reasonable number of the decoder units so that drive pulses for controlling additional displays can be produced. In practice the user of the system sets the individual comparator setting switches 80 so that the time relationship between the occurrences of the respective display drive pulses, as well as the-duration of each such pulse, are coordinated as desired. The setting device 17 is then adjusted to coordinate the phase BUREOMPI ' of the display drive pulses with the camera drive pulses. If a different camera is used which exhibits a greater or lesser degree of propagations delay all of the display drive pulses can be simultaneoulsly phase shifted to accommodate the new camera merely by adjusting the setting device 17.The output signal generator 16 is also effective to enable simultaneous phase shifting of its output signals pulses relative to the output signal pulses from the output signal generator 14. The preferred signal generator 16 comprises a pair of digital comparators 90, 92 and a digital signal processor 94.The coirparators 90, 92 each have an input terminal 96 connected to the timing signal generator output 45 via the inter¬ connect 52, a setting input terminal 98 and an output terminal 100. The comparators produce individual output signal pulses from the terminals 100 when the binary coded signals to both of their respective input terminals are identical. The output pulses from the terminals 100 each have a duration of one clock pulse.The processor 94 is preferably a binary adder having input terminals 102, 104 and an output terminal 106. The input terminal 102 is connected to a manually operated setting switch 108 (which can be identical to the switches 80 referred to above) and the output terminal 106 is connected to the setting input terminal of the comparator 92.The setting device 18 adjustably controls the time in each cycle at which the respective signal pulses from the comparators 90, 92 are produced. The preferred setting device 18 is connected to the adder input terminal 102 and to the input terminal 98 of the comparator 90. The device 18 is set to produce a predetermined binary coded output signal which is input to both the comparator 98 and the adder 94. The output from the adder 94 is a binary coded signal representing the algebraic sum of the binary coded signals at the adder inputs.Assuming a signal representing a positive number is input to the adder input 104, it should be apparent that the signal input to the comparator 92 from the adder represents a larger number than the signal input to the comparator 90 from the setting device.Accordingly as the timing signal generator produces output r signals during each cycle the comparator 90 produces an output signal pulse when the signal at its inputs are equal, while the comparator 92 produces a subsequent output signal pulse when the signals at its inputs are equal. The interval between the pulses is determined by the switch 108. Changing the signal produced by the setting device 18 alters the time in each cycle that the output signal pulses are produced without changing the interval between them. In the preferred construction the output pulses from the comparators 90, 92 are fed to respective set and reset terminals of a flip-flop 110 which, in turn, produces an output drive pulse having a duration determined by the interval between the comparator output pulses. Changing the output of the setting device 18 thus changes the time in the cycle at which the drive pulse is produced but not the duration of the drive pulse. The setting device 18 can be a manually operated switch like the switches 80 referred to above, or can be formed by the output of a digital computer if extremely rapid changes in the output from the device 18 are desirable. Rapid changes in the output from the device 18 can permit the generation of multiple output pulses within a given cycle of operation of the counter 42 and can be of importance in information fetching when applied to computer systems.While the system 10 has been illustrated and described as including both the output signal generators 15 and 16 it should be apparent that a system embodying the-invention can be constructed utilizing only one or the other of these output signals generators. Moreover it may also be desirable, in some circumstances, to utilize a signal generator 16 and associated setting device 18 in place of a decoder in the output signal generator 15. Such a replacement would provide additional flexibility to the phase shifting capability of the signal generator 15.While only a single system including alternative phase shifting output signal generators embodying the invention has been illustrated and described, the present invention is not to be considered limited to the precise constructions disclosed. Various adaptations, modifications and uses of the invention may occur to those skilled in the arts to which the invention relates and it is the intention to cover all such adaptations, modifications and uses which fall within the scope and spirit of the claims. | Claims1. A system for producing multiple cyclic output signals occurring at intervals which are adjustably variable cortprising: a) a timing signal generator having an output producing cyclic digitalized timing signals; b) a first system output signal generator having an input connected to said timing signal generator output and at least one output forming a first system output, said first system output signal generator producing at least a first system output signal in response to the occurrences of a predetermined timing signal generator output; c) a second system output signal generator having a first input receiving said timing signal generator output, a second input, and a plurality of outputs defining second system outputs; and d) setting means connected to said second input of said second system output signal generator, said setting means producing an adjustable setting signal conditioning said second output signal generator to produce said plurality of second system output signals in response to occurrences of a timing signal generator output signal bearing a selected temporal relationship to said predetermined timing signal generator output signal.OMPI The system claimed in claim 1 wherein said second system output signal generator comprises a processor unit and a decoder unit, said processor defining said first and second inputs and said decoder unit defining at least one of said second system outputs, said processor effective to process signals at said first and second inputs and transmit a resultant digitally coded signal to said decoder.The system claimed in claim 2 wherein said timing signals are binary coded signals, said setting means provides a binary coded signal to said second input and said processor is defined by a binary adder effective to produce binary coded output representations corresponding to the algebraic sum of the signals input to said adder.The system claimed in claim 3 wherein said decoder comprises first and second comparators each having a reference input, a setting input and an output, corrparator setting means coacting with the setting input of each corrparator for governing the binary adder output signal to which the respective comparators respond, said coπparators producing separate output pulses.OMPI ► 5. The system claimed in clam 1 wherein said second system output signal generator comprises first and second digital comparators each having a reference input receiving said timing signals, a setting input and an output, and a digital processor having an output connected to the setting input of one of said corrparators, said setting means connected to an input of said processor and to the setting input of said other comparator whereby one of said corrparators produces an output dependant upon the timing signal and said setting means while the other comparator produces an output dependant upon the timing signal and the processor output.6. A system for- shifting the time of occurrence of at least two cyclic signals relative to a third cyclic signal comprising: a) time signal means for producing digitally coded cyclic time signals; b) an output signal generator means responsive to said time signals and effective to produce said third signals; and, c) second output signal generator means responsive to said time signals for producing said at least two cyclic signals, said second output signal generator means comprising at least first and second digital corrparators each having a set input, a reference input and an output,O PI a digital signal processor having an output associated with the input of at least one corrparator, and setting ireans connected to a processor input for conditioning operation of the processor.7. The system claimed in claim 6 wherein said processor output is connected to inputs of both comparators and a second input of said processor is connected to said time signal means, said comparators associated wnth respective comparator setting means whereby each corrparator produces an output signal at a time dependent upon the processor output signal and the respective comparator setting means.8. The system claimed in claim 6 wherein said setting means is connected to an input of the other of said comparators, said time signal means is connected to inputs of both corrparators, and second setting means is connected to a second input of said processor, said first corrparator producing an output signal occurring at a time dependent upon said time signal and the condition of said first and second setting means as reflected by the processor output, said second comparator producing an output signal occurring at a time dependent upon the condition of said first setting means and said time signal. 9. The system claimed in claim 8 wherein said setting means provides binary coded outputs and said processor is defined by a binary adder effective to produce an output reflective of the algebraic sum of said setting means outputs. | SINGER CO | WORTHINGTON J |
WO-1979000528-A1 | 1,979,000,528 | WO | A1 | EN | 19,790,809 | 1,979 | 20,090,507 | new | F02D5 | F02D19 | F02D19, F02D41 | F02D 19/02, F02D 41/00F2, F02D 41/14D1B, F02D 41/14D3B, F02D 41/14F | INTERNAL COMBUSTION ENGINE UTILISING LIQUEFIED GASEOUS FUEL | In an air/fuel supply system for enabling an internal combustion engine to utilise liquefied gaseous fuel efficiently, a solenoid operated fuel injector (18) injects the fuel in a liquid state into a mixing region (26) of the induction system. A control system monitors the cooling effect of the vapourising fuel by measuring the temperature difference between a pair of temperature sensors (44, 46), respectively upstream and downstream of the mixing region and compares the measured temperature difference against a preset reference level to derive an error signal. The error signal is applied to control the fuel injector and regulate the fuel supply to maintain the temperature difference and related mixture strength constant at a value set by the reference level. The reference level may be controlled by monitoring other parameters or operating characteristics e.g. intake air humidity, exhaust gas composition or firing voltage values, to determine and hold the optimum setting. | INTERNAL COMBUSTION ENGINE UTILISING LIQUEFIED GASEOUS FUELTechnical FieldThis invention relates to internal combustion engines and to their ai /fuel supply systems. More particularly it is concerned with means for enabling an internal combustion engine to utilise liquefied gaseous fuel in an efficient manner.The term liquefied gaseous fuel is used herein to denote a combustible fuel which at atmospheric pressure exists entirely in the vapour phase at least at normal room temperature, 15.5°C (60 F), but which is liquefied by superatmospheric pressure and/or by cooling to lower temperatures.This term liquefied gaseous fuel therefore includes fuels which under atmospheric pressure at 0°C are substantially below their critical pressure and critical temperature so that they can be liquefied by pressure alone. Such fuels, herein referred to as fuels of the liquefied petroleum gas (LPG) type, are commercially available as bottled gas and are generally composed predominantly or wholly of butane, propane and/or propylene.The term liquefied gaseous fuel , as defined above, also includes fuels known as cryogenic fuels which have a critical temperature substantially below 0°C so that they can only exist in the liquid phase at low sub-zero temperatures. Such cryogenic fuels include natural gas (methane) and hydrogen.Background ArtLPG type fuels have already been used forO PI internal combustion engines, for example in motor vehicles. The arrangements employed for this purpose, hov/ever, have usually involved evaporating the fuel from a tank in which it is stored as a liquid under pressure and delivering the fuel in a gaseous state through a supply line to a modified carburettor, and thence to the engine. The operator controls the speed of the engine by causing the carburettor to deliver more or less fuel as appropriate. Such prior art arrangements, however, are often subject to significant disadvantages including poor control of the fuel/ air ratio of the mixture passed to the engine, and tend to have a relatively low efficiency and high fuel consumption.Proposals have also been made for adapting internal combustion engines in order to utilise cryogenic fuels of the kind mentioned above, but again the prior art arrangementshave not been entirely satisfactory and, in particular, the operation thereof has in general been subject to difficulties in maintaining a close control of the fuel/air mixture necessary to give and maintain high efficiency.Disclosure of Invention An object of the present invention is accordingly to provide improved arrangements for adapting internal combustion engines in order to utilise liquefied gaseous fuel, either LPG type or a cryogenic fuel, which can effectively be controlled to operate at relatively high efficiency with an enhanced powe - output.According to the present invention, in anOMPI internal combustion engine having an air and fuel supply system which includes inlet duct means wherein there is a mixing region in which liquefied gaseous fuel supplied from a storage tank or reservoir mixes wit combustion air supplied from an air intake so as to provide a substantially homogeneous combustible fuel/air mixture which passes to the respective combustion chamber or chambers of the engine prior to ignition there is provided in combination: (a) a fuel supply line arranged to convey the liquefied gaseous fuel in a liquid state from said tank or reservoir to nozzle means through which, in use, the liquefied gaseous fuel is introduced directly into said mixing region where it is subjected to rapid vapourisation and mixing with the combustion air accompanied by cooling of such air;(b) sensing means arranged to sense the temperature difference between the incoming air upstream of said mixing region and the fuel/air mixture downstream of said mixing region so as thereby to monitor the cooling effect of the vapourisation and mixing of the liquefied gaseous fuel which cooling effect is related to the fuel/air ratio of the mixture, and(c) control means arranged to respond to the temperature difference sensed by said sensing means and to operate, in use, automatically to control the relative proportions in which the fuel and air constituents of the mixture are mixed, thereby to control the fuel/air ratio of the mixture, in such manner as to establish and maintain said temperature difference at a predetermined particular value which is selectable so as to correspond to the value of said fuel/air ratio of the mixture which provides a desired level of engine performance; said sensing means and said control means together constituting a mixture control system.Generally, in practical embodiments of the invention, the sensing means and the control means will together in effect constitute a servo control system, with the control means being adapted(a) to relate or compare an output of the sensing means representative of the actual temperatu difference sensed with a preset reference quantity representative of said particular value thereby to derive an error quantity representative of the extent to which said actual temperature difference differs from said particular value, and (b) to utilise said error quantity through a feedback loop to provide a mixture control output effective to control operation of a metering control device which regulates the supply to said mixing region of one of the constituents of the fuel/air mixture thereby to vary the fuel/air ratio in a sense which causes said actual temperature difference to approach said particular value and so reduce or eliminate said error quantity. Usually, the metering control device will comprise a valve operable to regulate the supply of the liquefied gaseous fuel which is injected into the mixing region through the nozzle aperture of a fuel injector nozzle device. BUR£4^OMPI This fuel supply valve may be disposed in the fuel supply line leading to the nozzle device but preferably it is incorporated in the nozzle device, conveniently in the form of a needle valve adapted to vary the effective size of the nozzle aperture.The fuel supply valve will generally be associated with an actuator, for example an electrically controlled actuator such as a solenoid, so that the quantity of fuel passing through the nozzle aperture can be varied or regulated by progressive or, advantageously, intermittent periodic opening and closing of the valve. Thus, in preferred embodiments utilizing a fuel injector nozzle device having a solenoid operated needle valve, the solenoid is energised by an electrical drive signal of pulse form derived from a pulse generator so that the valve is caused to open and close intermittently in repetitive cycles of operation at a convenient .predetermined rate, cycles per second for example, the pulse generator being set to provide, at a given bias, a predetermined pulse length. To regulate the supply of the liquefied gaseous fuel as required, the error quantity derived in the control system is utilised to modify or modulate this electrical drive pulse signal so as to vary the pulse length and thereby the ratio of opening time to closing time of the valve within each cycle of operation. Ideally, such pulse signal should approximate to a square wave, and it has . , been found that this form of control arrangement can give a very reliable and responsive positive control of the operation of the valve.The sensing means will generally comprise a pair of temperature sensors disposed in the path of the incoming combustion air or fuel/air mixture respectively upstream and downstream of the mixing region. Such temperature sensors may be of any convenient type, for instance, mechanical, electrical such as thermocouples or thermistors, or electro-mechanical such as pneumatic/electrical or hydraulic/electrical. They should, hov/ever, be sensitive to small temperature changes, ideally changes of less than 1 C, and they should have quick response characteristics.When the temperature sensors are in the form of electrical transducers they are associated with means for deriving from their outputs an electrical signal representative of the difference between the temperatures sensed by each. This signal, forming the output of the sensing means, is then supplied to a comparator element of the> control means wherein it is compared with an electrical reference signal of preset value constituting the reference quantity representing the temperature difference which it is desired to maintain between the sensors. The result of this comparison produces the error quantity in the form of an electrical error signal which is processed to provide the mixture control output from the control system for controlling operation of the valve of the fuel injector device or other metering control device so as to vary the fuel/air ratio of the mixture and establish or re-establish the desired temperature difference.The inlet duct means will generally comprise a duct or conduit from the air intake which incorporates or is connected to the engine manifold leading to the combustion chamber or chambers of the engine and usually, with the control system arranged to control regulation of the fuel supply,it will contain, upstream or downstream of the mixing region, a variable throttle valve associated with remote control means for controlling the supply of the combustion air or fuel/air mixture and thus the speed of the engine.When the variable throttle valve is operated so the supply of air is varied and, in turn, the control system responds in a manner which tends to maintain the fuel/air ratio of the mixture constant. Thus, in order to increase the engine speed, the operator opens the variable throttle valve. This allows more air to be 'drawn into .the inlet duct whic results in a decrease in the fuel/air ratio and an increase in the temperature sensed by the sensor downstream of the mixing region. This is because the temperature difference between the two sensors is dependent both on the amount of fuel passing through the nozzle and on the amount of air flowing through the inlet duct. To maintain the sensed temperature difference .constant, therefore, the control system responds to cause the quantity of fuel passed through the nozzle to be increased in proportion to the air flow increase, with a resulting increase in the fuel/ air ratio tending to restore the latter to its original value.Such variable throttle valve is conveniently ._ a conventional butterfly valve in the inlet duct} under the direct control of the acceleratorJU EATT pedal of the vehicle in the usual manner.Although the control system can be designed to respond quickly to changes in the temperature difference following movements of the variable throttle valve, there will generally be a slight delay especially following a rapid or snap opening of the throttle. Moreover, following a rapid or snap opening of the throttle, it may be desired temporarily to enrichen the mixture to improve acceleration characteristics as with a conventional acceleration pump . In some cases, it may therefore be desirable to provide additional means arranged to respond to rapid opening of the throttle so as to produce a transient control signal which is utilised to cause the supply of the liquefied gaseous fuel to the mixing region to be increased before sufficient time elapses for control of the fuel/air ratio of the mixture in accordance with the cooling effect of the vapourising fuel on the incoming air to be re-established.In practice, such transient control signal can readily be provided, for example, by a signal representative of the rate of change or first order derivative , ζ ) of throttle position obtained by differentiating the output of a position sensor or electrical transducer responsive to the position or setting of the throttle, or, alternativel and sometimes preferably, by a signal produced by the output of a pressure responsive transducer arranged to respond to sudden changes in pressure in the inlet duct which result from rapid opening movements of the throttle during operation of the engine. The mixing region must of course be sufficiently long for complete vapourisation and mixing of the liquid fuel introduced therein before the mixture reaches the downstream temperature sensor. At the same time, however, it is generally desirable to keep the inlet duct means as compact as possible but the extent to which this objective can be achieved is somewhat limited if the inlet duct means is in the form of a straight through duct or conduit from a single air intake opening, with the nozzle device placed along the length of the duct or conduit to inject the fuel directly into the path of the entire airstream because this airstream at this point will generally be moving very rapidly, such that the mixing region downstream of the nozzle device must be of substantial length to ensure complete vapourisation and mixing of the fuel.In a preferred arrangement in some cases, the nozzle device may therefore be arranged to inject the fuel into the air supply conduit at a place where there is relatively still air, this being achieved by designing a portion of the inlet duct means in the form of an elongate mixing chamber having inlet apertures distributed along its length for the entry, through suitable filter means, of the combustion air from the air intake, one end of the mixing chamber being connected to the engine inlet manifold and the opposite end being closed by an end wall in or adjacent which the nozzle device is located. By this means, a better mixing efficiency with a shorter., more compact, inlet duct or conduit can be obtained, the throttle in this case being conveniently placed downstream of the nozzle, beyond the downstream temperature sensor. This arrangement may also be more convenient when converting an existing engine having a conventional carburettor, where it is desired to retain the carburettor and use the existing carburettor throttle valve so that basically the inlet duct or conduit and fuel supply nozzle device can form a unit which can be attached directly to the existing carburettor air intake. When using an LPG type fuel, the fuel supply line will generally be a pipe adapted to convey the fuel at superatmospheric pressure from a pressure vessel or tank in which it is stored so that the fuel remains in the liquid state right up to the nozzle device, and the rapid vapourisation takes place as soon as the fuel passes through the nozzle aperture by reason of the lower atmospheric or sub-atmospheric pressure- in the mixing region of the inlet duct or conduit. It will be appreciated that in this instance the cooling of the intake air which occurs arises directly from the vapourising of the liquid fuel. This cooling effect incidentally assists by increasing the volumetric efficiency and is directly dependent on the quantity of fuel passing through the nozzle.In order to ensure that the LPG fuel reaches the nozzle aperture in a liquid state even if it should become overheated and partially vapourised at some earlier point within the fuel supply line, it may sometimes be advantageous to arrange for a bight or loop of the fuel supply line immediately adjacent the nozzle device to pass through the mixing region in the path of the vapourising fuel from the nozzle device so that following fuel is'BUREAU pre-cooled before reaching the nozzle aperture.When using a cryogenic fuel, this will generally be stored in its liquid phase in a thermally insulated cryogenic tank at the boiling point of the liquid relative to the pressure within the tank (usually 0 - 25 p.s.i). As heat leaks into the tank, in which the temperature will be approximately - 160°C at atmospheric pressure in the case of methane for example, the liquid fuel boils and the gas produced is vented to atmosphere via a safety valve which determines the final equilibrium pressure and so the final temperature within the tank. The fuel supply line for the liquid fuel in this case will be a heat insulated fuel pipe leading from below the level of the liquid fuel to the nozzle means which is preferably a fuel injector nozzle device incorporating a needle valve as referred to previously and which will also be heat insulated. Also, when using a cryogenic fuel, provision may need to be made for an additional bypass nozzle to be brought into use to pass extra gaseous fuel on starting an engine that has been standing for some time because, under these conditions, the relatively hot fuel supply pipe, which may have warmed up to ambient temperature, will be likely to evaporate a high proportion of the first rush of liquid fuel to emerge from the cryogenic fuel tank such that the main nozzle which is used during normal operation would alone be unable to pass the greatly increased volume of gas.It will be appreciated that in arrangements as already described in accordance with the invention, the mixture control system acts basically BU R ΓΞΛTΓ to maintain the temperature difference between temperature sensors placed upstream and downstream of the mixing region substantially constant at a value set by the value selected for the reference signal forming the reference quantity or standard, assuming the latter is maintained constant, and this temperature difference will generally correspon to a constant fuel/air ratio so long as the characteristics of the intake air, particularly the temperature and humidity of the air passing into the intake, do not vary significantly.Hov/ever, for best results it is necessary selectively to pre-set the reference signal at a value which will provide a fuel/air ratio giving optimum performance, and under some conditions substantial changes in temperature and humidity of the intake air may occur during operation of the engine which means that to maintain optimum performance, it will be necessary to re-select and re-set the value of the reference signal.The effect of variation of humidity can be particularly significant at relatively high inlet temperatures of the incoming air and results from the latent heat of vapourisation given up by the v/ater vapour when it cools and condenses folloving the injection of and vapourisation of the liquefied gaseous fuel. If, at a certain stage, air of higher humidity is taken in, the effect will be to enrich the mixture if an attempt is then made to keep the temperature drop constant since more fuel will need to be injected to maintain such constant temperature drop.In a further development of this invention whic may be utilised if desired, especially when it is anticipated that significant variations in the humidity of the incoming air may occur during running of the engine, additional means may also be provided for finding or selecting the correct value of the reference signal which corresponds to the temperature difference required between the temperature sensors under the particular conditions of operation pertaining, and for adjusting or re-setting this when necessary, for always providing the mixture with the fuel/air ratio needed for optimum performance, this corresponding generally to the chemically correct stoichiometric value.For example, for a given engine installation, the temperature difference required can be computed or determined empirically for different temperatures and humidities of the inlet air. This data can then be fed and stored in an electronic memory incorporated in the mixture control system, and with the provision also of means for continuously monitoring or measuring the humidity as well as the temperature of the incoming air, the measurements so obtained can be compared v/ith the data in the electronic memory to enable the reference signal to be continually adjusted or reset, either manually through the intervention of an operator or automatically through a servo type control, so as to correspond to the correct value of the temperature difference required.Thus in this more sophisticated arrangement the additional means is effective to enable or cause the reference signal to be selected and reset as necessary taking into account the humidity and/or temperature of the incoming combustion air from the air intake, and any changes therein.-BϋREΛtTOMPI Conventional means for measuring the humidity of the air can be used, such as a so called damp string comprising a moisture sensitive fibre or filament of which the tension varies with humidity and which is connected to a device, conveniently an electrical transducer device, sensitive to the tension.In an alternative arrangement adapted to enable or cause the reference signal to be selected and re-set as necessary to maintain a temperature difference corresponding under working conditions to an optimum fuel/air satio, means can be provided for monitoring the exhaust gas in respect of its carbon monoxide or v/ater content. It has been found that, in practice, a one per cent concentration of carbon monoxide in the exhaust gas corresponds to a substantially stoichiometric fuel/air ratio of the input mixture, so that by measuring the carbon monoxide, for example with a conventional Luft cell, a signal representing any deviation from a one per cent concentration can be produced and utilised in a servo control arrangement to select and re-set the value of the reference signal so as to correspond to a temperature difference which reduces such deviation towards zero.If, alternatively, it is desired to monitor the amount of water in the exhaust gas, measurements can be conveniently made by an infra- red absorption device for example, and checks are made periodically to determine whether or not the percentage amount of v/ater in the exhaust is a maximum. In general, v/hen fuel is consumed most efficiently, as v/hen the fuel/air ratio of the'BUREΛTOMPI P mixture is stoichiometric, the largest percentage amount of water in the exhaust is obtained. This can be determined by further providing means which will periodically vary briefly the setting of the fuel supply regulating means, such as by producing and applying a signal intentionally to vary the reference signal value in a predetermined manner, so as temporarily to change the fuel/air ratio over a certain range. Thus, in effect, a scanning search is carried out, and the successive measurements of the v/ater content during this search stage will reveal the maximum' value from which can be deduced or derived a signal for checking or re-setting the reference signal for a temperature difference which will correspond to the correct mixture composition.For spark ignition engines, other possible, and perhaps preferred, additional control arrangements for overcoming the problem of possible variations in the temperature and humidity of the incoming air by automatically selecting and re-setting the reference signal to maintain it at a value corresponding to the fuel/air ratio required for optimum performance may rely for their operation upon measurements of the firing voltage characteristics in the spark ignition system.The firing voltage is the voltage required to ionize the mixture within the spark plug gap in the combustion chamber, so making the mixture conductive and allowing current pass in the form of a spark. As soon as a spark is struck , the voltage falls to a much lower level for the duration of the spark.Although the firing voltage depends on a number of factors, including engine speed, compression ratio, mixture swell etc., it is also another parameter which is dependent upon the strength of the mixture or fuel/air ratio and it has been found generally to have its lowest value when the mixture is substantially stoichiometric providin optimum efficiency and is significantly higher v/hen the mixture is either richer or weaker. Thus, with an LPG type liquefied gaseous fuel, the drop in firing voltage at a correct stoichiometric fuel/air ratio is very considerable and is sharply defined so that, in practice, it represents a very satisfactory parameter for measuring the performance and for controlling a reference signal level which determines and maintains mixture strength and engine performance. For example, under a given set of conditions, the firing voltage may typically rise from its lowest value, corresponding to the mixture having a correct stoichiometric ratio, by up to 10,000 volts or more v/hen the engine is running on a weak mixture. It will also rise considerably if the engine is running on a rich mixture, and if the effective composition of the mixture fed to the combustion chamber varies too much from stoichiometric, in extreme cases, the ignition system becomes incapable of supplying the required voltage and the engine misfires or ceases to run. With a control system using the temperature difference sensing arrangement of the form hereinbefore described the correct value of the temperature difference which is required to be represented by the reference signal, for providing optimum performance with a substantially stoichiometric fuel/air ratio, will accordingly beOMPI■ - the temperature difference produced in operation when the firing voltage is a minimum.In practical embodiments, this correct value, or at least the equivalent temperature difference reference signal, can be determined automatically by providing means for periodically varying the value of the reference signal in a periodic scanning sweep or search to determine at what point the firing voltage becomes a minimum, in a manner similar to the already mentioned in relation to determining what value of reference signal gives the maximum percentage amount of v/ater in the exhaust.The firing voltage may be measured directly or, preferably, the times taken for building up to the firing voltage for different values of the reference signal are measured and compared with one another. The voltage build-up across the spark gap does not of course take place instantaneously but generally follows a sine wave curve and is related to the value of the firing voltage. The time taken to build up to the firing voltage can readily be measured by conventional electronic instrumentation. With a correct stoichiometric fuel/air ratio, the time taken for build-up to the firing voltage may typically be about 30 micro seconds but, in contrast, for incorrect non-stoichiometric fuel/air ratios the time for build-up may typically take about 50 micro seconds.With this kind of arrangement, the periodic search or systematic scanning variation to determine the correct level or value of the temperature difference reference signal will generally be performed at intervals, for example, of seconds or minutes according to how often it is considered a BU ETTOMPI check should be made in the particular conditions existing. After the correct level or value of the temperature difference reference signal is found in each search or scanning sweep, the actual level or value of the reference signal is adjusted if necessary, preferably automatically through a servo type control arrangement, and is locked or held constant until the next search or scanning sweep is made whereupon it is again adjusted if necessary. The periodic scanning sweeps or searches may be carried out at either regular or irregular intervals, and each may be initiated by an appropriate trigger signal. This could be arranged by a preset timer or clock set to trigger off a scanning sweep or search signal generator at the required intervals but there are of course many othe means v/hich can be employed in practice for providin such trigger signals. For instance, they could also be provided by a circuit under the control of a manually operated switch, or even by a switch or other means responsive directly to movements of the throttle control when this is fitted for controlling engine speed.Details of suitable electronic equipment and techniques needed will be familiar to persons skilled in the art v/ho should have no difficulty in adapting conventional electronic equipment and circuitry for the practical realisation of the further developments indicated above. In effect, the arrangements described in connection with these developments involving an analysis of the exhaust gases or measurement of the firing voltage characteristics provide periodic checks of the fuel/air ratio in terms of theO PI operating performance of the engine and automatically adjust and maintain the temperature difference reference signal or reference standard for the mixture control system at a value which provides the correct fuel/air ratio for optimum performance, and the problem of the effect of varying temperature and humidity of the intake air is overcome.In adapting internal combustion engines to utilise liquefied gaseous fuel in accordance v/ith the invention, it will be clear that many advantages arise and there are a number of factors v/hich tend to increase pov/er output and/or to lower fuel consumption including the follov/ing: 1. The cooling of the ingoing charge air which, by increasing the density, increases volumetric efficiency.2. The lowering of the temperature at the commencement of combustion whereby the compression ratio can be increased so improving thermal efficiency and power output.3. The operation of the temperature sensors in constantly monitoring, in effect, the fuel/air ratio and correcting it to keep it at any preselected optimum for any given engine and liquefied gaseous fuel.4. A capability for increasing the specific power output so that it is possible to use a smaller engine v/hich is cheaper, lighter, smaller and has low mechanical losses.5. The increase in power due to (1) above is available at all engine speeds, unlike turbo- chargerswhich are usually ineffective at low engine speeds. Brief Description of DrawingsIn the accompanying drawings, Figure 1 is a schematic diagram illustrating the manner in which an internal combustion engine may be adapted to utilise liquefied gaseous fuel in accordance with a preferred embodiment of the invention;Figure 2 is an enlarged detail view shov/ing the fuel injection and mixing means of the arrangement of Figure 1; Figure 3 is a schematic block diagram of the basic mixture control system for the arrangement of Figure 1;Figure 3 , is a detail diagram of the voltage supply arrangement for the system of Figure 3; Figure 3b. is a diagram showing a modification of a part of the control system illustrated in Figure 3;Figure 4 is a more detailed schematic circuit diagram of the position of the control system of Figure 3 to the left of the point marked X ; Figure 5 is a more detailed schematic circuit diagram of the remaining portion of the control system of Figure 3? to the right of the point marked X andFigure 6 is a schematic block diagram shoving the arrangement of additional control means, relying on firing voltage measurements for operation, which may also be provided as a modification to the basic mixture control system. Preferred Mode for Carrying Out the InventionIn the preferred embodiment which is illustrated by way of example in the drawings, a fuel tank 10 of conventional design is provided for containing LPG type liquefied gaseous fuel. A withdrawal pipe 12 reaches to the bottom of the fuel tank to ensure a liquid take off, and a hand valve 14 connects with a fuel supply pipeline 16 which is arranged to convey the fuel in a liquid state to a fuel injector nozzle device 18 via a vacuum operated lock-off valve 20 combined with a fuel filter unit. This valve 20 is conveniently arranged to be opened under the control of a vacuum pipeline 22 connected to the engine inlet manifold indicated at 24. The fuel injector nozzle device 18 incorporates a solenoid operated needle valve operable to regulate fuel flow through the aperture of a nozzle 25 which opens into an elongate mixing chamber portion 26 of an inlet duct structure 28 which leads from the air intake to the combustion chambers of the engine via the inlet manifold 24. In this embodiment the inlet duct structure 28, shown in greater detail in Figure 2, is conveniently provided by adapting a conventional type of tubular air filter and has an outer cylindrical casing 30 with a series of air inlet apertures 32 along its length. These form the air intake. The casing is lined with a standard cylindrical paper filter element 3- defining a central hollow cylindrical cavity forming in this case the elongate mixing chamber portion 26. The casing 30 is closed at one end by a cap 36 providing an end wall and it is at this position that the fuel supply nozzle device 18 is placed, as shown. It will be noted that before connection with the fuel injector nozzle device 18 the supply pipeline 16 is shown as entering the mixing chamber and has a coil 17 in the path of vapourising fuel 5 from the nozzle. This provides some pre-cooling which can be useful to ensure that all the fuel is in a liquid state when it reaches the nozzle aperture.At the opposite end, the casing 30 terminates10 in a short tubular extension 38 of reduced diameter which is connected to the engine inlet manifold 24, conveniently through a connecting section of conduit 40 v/hich may represent part of an existing air intake system of a conventional15 carburettor and which includes a butterfly type valve 42 forming variable throttle valve means under the direct control of the operator or of a governor for regulating the engine intake and speed. Upstream of the mixing chamber,20 adjacent the air intake, there is provided a temperature sensor 44 responsive to the temperature of the incoming air, and a second temperature sensor, indicated at 46, is placed downstream of the mixing chamber in a position, conveniently25 adjacent the open end of the casing, where the fuel will be fully vapourised and mixed v/ith the air.It will be seen that with this structure, there will be a region of relatively still air at the closed end of the mixing chamber where the30 fuel is injected. This helps to ensure that the fuel will vapourise and mix with the air in the shortest possible length of mixing chamber, additional air entering at various places distributed along the length of the mixing chamberOMPI ~ ~* after at least most of the fuel has vapourised so that there is a progressive mixing.Adjacent the throttle valve 42 on the engine side the conduit 40 is provided with a short side limb forming a housing 52 communicating with atmosphere through a small air vent 54. The housing 52 is partitioned by the diaphragm of a pressure transducer 50 which, in response to sudden variations in pressure within the conduit 40 following rapid opening movements of the throttle, provides a transient electrical signal output which is fed to the mixture control system hereinafter described wherein it can be utilised for causing the mixture strength to be enriched under these conditions before full control is re¬ established in an equilibrium state by the temperature sensors.The temperature sensors 44 and 46 are conveniently electrical transducers, either- thermocouples or thermistors, and they are incorporated in a mixturφ control system wherein their outputs are combined (at 56 in Figure 1) to provide a signal representative of difference between the temperatures sensed by each. This temperature difference signal is then compared(at 58 in Figure 1) v/ith a preset reference signal to derive an error signal providing the control output of the mixture control system v/hich is applied to control operation of the valve of the fuel injector device 18 so as to regulate the fuel supply as required, in accordance v/ith the invention.The basic control system is shown in more detail in Figures 3 to 5 and is designed (a) to compare the temperature of the inducted air against • that of the vapourised fuel/air mixture,- (b) to compare the temperature difference sensed (ΔT) against a preset reference signal level to give an error signal proportional to the error in the fuel/air ratio, and (c) to convert the error signal into a fuel injector control signal (the mixture control output signal) to correct the fuel/air ratio and maintain it at a constant value under all engine loads and speeds. Assuming the engine is installed in a vehicle, the control system is pov/ered off the vehicle battery via a filtering and voltage stabilising circuit, as shown in Figure 3§__ supplying a stable centre-tapped voltage to the control circuits.The temperature sensors 44 and 46 in the control system shown in Figures 3 and 4 are negative temperature co-efficient (ϊT.T.C.) thermistors, TH1 and TH2, v/hich are preferably of the fast response glass encapsulated bead type. The output signals from these, hov/ever, need linearising in a signal processing section of the circuit before comparison. Such linearisation is conveniently achieved by curve fitting : he output signals to an inverse exponential function derived from the charging curve of a capacitor fed via a resistor from a fixed voltage. V/hen suitably scaled this gives a linear output of temperature difference over a v/ide temperature range.Thus, referring to Figures 3 and 4, the thermistors TH1 and TH2 are fed from preset voltages (preset to allow adjusting out any manufacturing tolerance variations) and the current output signals are sensed by low value resistors, amplified by amplifiers DA1 and DA3, and are then compared vrith a scaled down curve of the charging voltage curve of a capacitor C1 fed through resistor R1 from the stabilised voltage supply Vs. Switching element DA2 switches when a sample of the scaled down capacitor voltage (from a potentiometer P which sets the scale factor) reaches the level of the output of the thermistor amplifier DA1 and passes a pulse which triggers a monostable element M of v/hich the output, acting through transistor TE, discharges and resets the capacitor C . Switching element DH4 triggers when the capacitor charging voltage curve passes the output level of thermistor amplifier DA3 and resets when DA2 triggers the capacitor reset monostable M.The initial temperature difference signal, provided by the resulting output from DA4 is in the form of a variable width pulse having a duration or pulse width t_ linearly proportional to the temperature difference between the tv/o thermistors, ΔT°C. This pulse signal is then converted into a dc voltage V. of which the amplitude is a linear function of the pulse width and thus of the sensor temperature difference ΔT°C. This is carried out in the pulse converter- element of the circuit v/hich includes transistors TE1 and TE2 controlling the charging of a high value capacitor C2.The voltage output signal V. is then passed to a comparator element wherein it is compared v/ith a preset voltage reference signal Nr selected by a potentiometer P v/hich sets the required temperature difference. This comparator element comprises a unity gain amplifier DA5 associated with preset voltage controls providing adjustable lead and lag characteristics to enable the loop transfer function to be controlled and adapted for response and stability.The resultant output is an error voltage signal forming an output control signal v/hich is applied to a proportional comparator (proportional control amplifier) DA6. DA6 is also fed with a triangular or sawtooth v/aveform from a waveform generator and produces a square wave pulse output v/hich has a fixed repetition rate and which provides the electrical drive signal for operating, via a switching circuit, the solenoid controlled needle valve of the fuel injector nozzle device 18.The effect of the error signal is to vary, in proportion to its value, the v/idth or length of the pulses produced, the pulse v/idth being variable from zero to full maximum duration over a narrow control band or narrow range of error signal.The output drive signal operates repetitively to open and close the fuel regulating needle valve, and is in effect modulated by the error signal to vary the pulse width and thereby the ratio of opening time to closing time of the valve in each cycle of operation, so regulating the fuel flow as required. It will be noted that the injector needle valve solenoid is powered directly by the battery voltage V-g via a ballast resistor Rg, thereby safeguarding the stabilised voltage supply lines from switching transients. As indicated in Figure 3b, instead of the thermistors TH1 and TH2, thermocouples TC1 and TC2 can be used as the temperature sensors in a differential pair configuration. In this case, a pre-amplifier (head amplifier) situated close to the mixing chamber should be used, the output of this then being further amplified by a buffer amplifier to provide the voltage output signal V. which is compared v/ith the voltage reference signal V_. Such thermocouple sensors must have a high value of the ratio of sensing area to thermal mass for ensuring a fast response.The output of 'the pressure transducer 50 after a snap opening of the throttle valve can be applied, as a transient additional control voltage, to temporarily enrich the mixture by causing it temporarily to alter appropriately the pulse width of the output drive signal, either by arranging for it to temporarily to reset the reference voltage level V or by arranging for it to change the amplitude of the sawtooth waveform fed to the proportional comparator.If, for speeding up the effective response of the system to rapid throttle operation, there is provided, as an alternative to the. pressure transducer 50, a throttle position sensor associated v/ith means for differentiating the output to derive a signal representative of the rate of change of throttle position, this signal, at least when it exceeds a predetermined value, may also be applied to control either the reference voltage level V or the sawtooth waveform amplitude thereby temporarily to vary the pulse width of the output drive signal. The response of the control system can similarly be speeded up for sudden changes in other engine operating parameters by feeding additional control signals representative of such parameters to the waveform generator to vary the amplitude of the sawtooth waveform, hence varying directly the pulse width of the output drive signal and thus augmenting the effect of the error signal.The reference voltage V can also be controlled or modified, if required, by other variable engine parameters or control functions providing appropriate additional control signals, thereby to control or modify the particular value of temperature difference maintained betv/een the temperature sensors and the overall operating characteristics of the system. In the specific embodiment described, such additional control signals could for example be arranged to drive a reversible electric motor forming a reference control controlling the setting of the potentiometer P .Thus, if required it can be arranged for the reference voltage to be controlled by a cruise economy function effective to adjust or reset its value to v/eaken the mixture under light load conditions. Or it can be controlled by quantities giving optimisation of mixture strength for different angles of ignition advance, throttle openings/engine speed combinations, engine temperature, or climate e.g. providing correction factors for changes in humidity and/or temperature of the incoming air, or for otherwise achieving optimum fuel/air ratios and performance under variable conditions of operation.In particular, as has already been indicated, the functioning of the system to give the correct fuel/air ratio for optimum or near optimum performance under variable conditions can be checked by monitoring the v/ater content of the exhaust gases or by monitoring the firing voltage characteristics in a spark ignition engine and by deliberately varying the fuel/air ratio periodically in a scanning sweep or search to determine, in a short duration sampling test period, whether or not these parameters have maximum and minimum values respectively. The results can then be utilised to select and adjust or reset the reference voltage v/hen required.By way of example, a manner in which such additional means of control may be incorporated in the embodiment described is illustrated in block diagram form in Figure 6. As shown, the arrangement relates to use of measurements of the firing voltage (or build-up times thereof) but it would be basically similar v/hen designed to relate to the alternative use of measurements of percentage water content in the exhaust gases.In the arrangement of Figure 6, to monitor the firing voltage characteristics a voltage receiver is provided which receives the voltage fed in the ignition system through the high tension lead to the distributor or to a spark plug. The voltage and current waveforms at least during the ignition voltage build-up to the point of discharge can be analysed and the signals produced representing the firing voltage or firing voltage build-up time are processed to provide data which is entered in an electronic memory in the signal processor, at least at the commencement and during each scanning sweep or search.The scanning sv/eeps or searches providing intermittent sampling are controlled by the sampling programmer in which trigger signals initiate at intervals the generation of sweep voltage signals of alternating form which are fed as control signals to a reference control, for example a reversible electric motor as previously mentioned, which controls the element that provides the reference voltage, namely, the potentiometerPr which is denoted in the block diag°ram as Reference Store .During each scanning sweep or search, the signal processor is activated by the sampling programmer so that it not only registers the successive changes in the firing voltage but also analyses the measurements to determine the minimum value thereof and compares this with the existing value at the commencement of the sv/eep or search. Any difference produces a corresponding reference error voltage signal output which is fed to the reference control which drives the potentiometer P and adjusts or resets the reference voltage to cause the mixture strength to be corrected accordingly. Each new setting of the reference voltage v/ill then be held until the next sampling test period.If additional control signals representing other parameters or operating characteristics are also fed to the Reference Control , if these are for the purpose of causing the mixture strength to be maintained at a value which is near to but not at its optimum or stoichiometric value for maximum pov/er output, as vith a cruise economy function for example as previously referred to, means will of course be provided for cancelling or artificially negating such additional control signals, or their effects, during each sampling test period to enable the correct reference signal voltage-BUREAU_ O PI< RNAΎ\ ^ necessary for minimum firing voltage (or maximum exhaust water content) to be established.It v/ill be appreciated that much of the circuitry involved in these further modifications and developments, representing refinements of the basic temperature control arrangement v/ill utilise integrated circuits and may well be incorporated in a suitably designed microprocessor unit. Industrial ApplicabilityThe invention is particularly suitable for spark ignition internal combustion engines, including conventional spark-ignition petrol engines, Wankel rotary engines and gas turbines, 5 which can all be arranged in accordance with the invention to utilise any of the liquefied gaseous fuels hereinbefore mentioned.If required, such spark-ignition internal combustion engines adapted to utilise liquefied10 gaseous fuel in accordance with the invention can also be arranged to have a dual fuel supply where this is advisable, as for example in the case of generator engines performing a vital function or engines of vehicles which may15 be used in places where a gas fuel supply may not be available. In a typical arrangement of dual fuel supply system, an original or existing petrol carburettor of a spark-ignition petrol engine is fed via a solenoid operated valve20 in the petrol supply line and the usual butterfly valve in the carburettor is used to control the air flow when operating on the liquefied gaseous fuel. The mixture supply pipe downstream of the carburettor will provide25 the mixing region for the liquefied gaseous fuel, and when the liquefied gaseous fuel supply system is to be used the solenoid valve in the petrol supply line is closed, sufficient time being allowed for the float chamber of the30 carburettor to empty itself before the liquid gas fuel supply system is sv/itched on. A similar solenoid operated valve is fitted inOMPI- the liquid gas fuel supply line and a three- way control switch is preferably used which enables only one solenoid to be activated at any one time and which provides an off position to allow either system to empty itself before switching to the other.For so-called diesel or compression- ignition engines the invention will generally best be applied by replacing the fuel oil injectors with spark plugs and using spark ignition.Thus, the invention is well suited to the conversion of compression-ignition engines, as in motor lorries or heavy commercial vehicles for example, to run as a spark-ignition engine on liquefied gaseous fuel such as LPG type bottled gas . Such a conversion involves' placing, in the air supply pipe to the inlet manifold, the variable throttle valve linked to the driver's accelerator pedal, the temperature sensors and the nozzle device, connecting the nozzle device to a gas cylinder by means of the fuel supply pipe which should of course be connected to the bottom of the gas cylinder so that it receives liquid fuel, and converting to a spark-ignition engine by replacing the injectors by spark plugs connected to an ignition circuit. The spark plugs may be inserted in the tapped bores initially occupied by the injectors although if the spark plugs are not of the correct size initially, it may be necessary to re-tap these bores. No modification need be made to the compression ratio of the engine. It is noteworthy that in conventional diesel engines, the power output is usually limited by the amount of smoke in the exhaust gas becoming unacceptable. This stage is 5 generally reached when only about 60% of the oxygen in the ingoing charge air is burnt with the fuel, and it has accordingly been proposed to use up this spare oxygen and obtain additional power by mixing propane10 or butane with the ingoing charge air. A modification of the engine in accordance with the present invention, however, may be used with greater effect to obtain increased efficiency and power output, in which respect15 the cooling effect on the ingoing charge air is especially beneficial.As an alternative to converting a diesel engine into a spark ignition engine in order to adapt it to utilise a liquefied gaseous20 fuel in accordance with the invention, in some cases where a fuel such as liquefied natural gas or methane is to be used, mixed in apprα-dmateϋy stoichiometric proportion with the ingoing charge air, the normal or part-modified25 existing diesel injection system may be retained if it is arranged to inject a small shot of diesel fuel as an ignition shot to - initiate each power stroke. Since the temperature near the end of the compression30 stroke in this arrangement will be less than the self-ignition temperature of methane but above that of diesel fuel oil, in effect the combustion is controlled by the injection of the fuel oil. The engine can also be regarded as functioning as a dual fuel engine.__OMPI_ | CLAIMS1. An internal combustion engine having an air and fuel supply system v/hich includes inlet duct means v/herein there is a mixing region in v/hich liquefied gaseous fuel supplied from a storage tank or reservoir mixes v/ith combustion air supplied from an air intake so as to provide a substantially homogeneous combustible fuel/air mixture v/hich passes to the respective combustion chamber or chambers of the engine prior to ignitio - characterised in that there is provided in combination:(a) a fuel supply line arranged to convey the liquefied gaseous fuel in a liquid state from said tank or reservoir to nozzle means through v/hich, in use, the liquefied gaseous fuel is introduced directly into said mixing region where it is subjected to rapid vapourisation and mixing with the combustion air accompanied by cooling of such air; (b) sensing means arranged to sense the temperature difference between the incoming air upstream of said mixing region and the fuel/air mixture downstream of said mixing region so as thereby to monitor the cooling effect of the vapourisation and mixing of the liquefied gaseous fuel v/hich cooling effect is related to the fuel/air ratio of the mixture, and(c) control means arranged to respond to the temperature difference sensed by said sensing means and to operate, in use, automatically to control the relative proportions in v/hich the fuel - and air constituents of the mixture are mixed, thereby to control the fuel/air ratio of the mixture, in such manner as to establish and maintain said temperature difference at a predetermined particular value v/hich is selectable so as to correspond to the value of said fuel/air ratio of . the mixture which provides a desired level of engine performance; said sensing means and said control means together constituting a mixture control system.2. An internal combustion engine as claimed in Claim 1 further characterised in that the control means is adapted to relate or compare an output of the sensing means representative of the actual temperature difference sensed v/ith a preset reference quantity representative of said particular value thereby to derive an error quantity representative of the extent to v/hich said actual temperature difference differs from said particular value, and to utilise said error quantity through a feedback loop to provide a mixture control output effective to control operation of a metering control device v/hich regulates the supply to said mixing region of one of the constituents of the fuel/air mixture thereby to vary the fuel/air ratio in a sense which causes said actual temperature difference to approach said particular value and so reduce or eliminate said error quantity.3. An internal combustion engine as claimed in Claim 2 further characterised in that the metering control device comprises valve means operable to regulate the supply of the liquefied gaseous fuel through said nozzle means to the mixing region of said inlet duct means.4. An internal combustion engine as claimedBUREAO PI, in Claim 3 further characterised in that said valve means comprises a needle valve incorporated in a fuel injector nozzle device which provides said nozzle means, said nozzle device having a nozzle aperture opening into said mixing region.5. A internal combustion engine as claimed in Claim 3, further characterised in that said valve means is associated v/ith an actuator and with means for generating a drive signal of pulse form effective to energise said actuator and cause the valve means to open and close intermittently in repetitive cycles of operation, and in order to control operation of the metering control device means are provided in the mixture control system for applying the error quantity to modify or modulate and control said drive signal so as to vary the ratio of opening time to closing time of the valve means to regulate the supply of the liquefied gaseous fuel as required. 6. An internal combustion engine as claimed in Claim 5? further characterised in that the actuator and valve means comprise a solenoid operated needle valve incorporated in a fuel injector nozzle device v/hich provides said nozzle means, said nozzle device having a nozzle aperture which opens into the mixing region.7. An internal combustion engine as claimed in Claim 3. further characterised in that the mixing region is provided by a portion of the inlet duct means v/hich is in the form of an elongate mixing chamber having provision for the entry through- filter means of the combustion air from the air intake at various places distributed along its length, one end of the mixing chamber being connected to the engine inlet manifold leading to the combustion chamber or chambers and the opposite end being closed by an end wall in or adjacent v/hich said nozzle means is located whereby the3 liquefied gaseous fuel introduced through the latter mixes progressively with incoming combustion air along the length of said mixing chamber.8. An internal combustion engine as claimed in Claim 3 jQ- which the inlet duct means contains10 variable throttle valve means for controlling the supply of the combustion air or fuel/air mixture and thus the speed of the engine, further characterised in that there is provided means arranged to respond to rapid opening of said throttle valve means so as t y- produce a transient additional control signal effective temporarily to increase the supply of the liquefied gaseous fuel to the mixing region, before sufficient time elapses for control of the fuel/air ratio of the mixture in accordance with said 20 temperature difference to be re-established.9. An internal combustion engine as claimed in Claim 8, further characterised in that said valve means of the metering control device is associated with an actuator and with means for25 generating a drive signal of pulse form effective to energise said actuator and cause the valve means to open and close intermittently in repetitive cycles of operation, and in order to control operation of the metering control device means are30 provided in the mixture control system for applying the error quantity to modify or modulate and control said drive signal so as to vary the ratio of opening time to closing time of the valve means to regulate the supply of the liquefied gaseous fuel as required, and circuit connections are provided for applying said transient additional control signal either to the drive signal generating means so as to control the drive signal directly or to reference control means effective to vary the preset reference quantity so as to control the drive signal indirectly.10. An internal combustion engine as claimed in Claim 2 further characterised in that the sensing means comprises: (a), a pair of temperature sensors in the form of electrical transducers disposed in the path of the incoming combustion air or fuel/air mixture respectively upstream and downstream of the mixing region and (b), means, associated vith said transducers, for deriving from their outputs an electrical signal representative of the difference between the temperatures sensed by each, which signal, constituting the output of the sensing means, is fed to a comparator element of the control means wherein it is compared with an electrical reference signal to derive the error quantity in the form of an electrical error signal which is utilised to provide the control output controlling operation of the metering control device. 11. An internal combustion engine as claimed in any one of Claims 2 to 10, further characterised in that the mixture control system includes reference control means adapted to operate following an alteration in the humidity and/or temperature of the incoming combustion air from the air intake so as to adjust or reset the reference quantity to represent a new particular value of said temperature difference effective still to maintain or restore the fuel/air ratio and level of engine performance at substantially the same value as existed before said alteration in the humidity and/or temperature of the incoming combustion air.12. An internal combustion engine as claimed i Claim 11, further characterised in that means are provided for monitoring the values of the humidity and/or temperature of the incoming combustion air and for comparing the measurements obtained vith reference data contained in data storage means so as to derive an output </hich controls operation of the reference control means.13. An internal combustion engine as claimed in any one of Claims 2 to 10, further characterised in that the mixture control system also includes reference control means for controlling the setting of the reference quantity and analyser means for monitoring and analysing, at least at intervals, a second operational parameter of the engine, otϊier than the cooling effect of the vapourisation and mixing of the liquefied gaseous fuel, v/hich is dependent on the mixture strength and v/hich also has a known characteristic value or quality v/hen the fuel/air ratio is stoichiometric or at an optimum value, said analysis being effective to check v/hether said characteristic value or quality is present and, if not, to derive a corresponding reference error quantity which is applied to said reference control means so as to cause the reference quantity to be reset and corrected thereby to change the fuel/air ratio and bring or restore it to its stoichiometric or optimum value.14. An internal combustion engine as claimed in Claim 13 further characterised in that the second operational parameter v/hich the analyser means is arranged to monitor and analyse is a quantity having a value which varies with mixture strength and attains a maximum or minimum when the fuel/air ratio is stoichiometric or at an optimum value, -and for ascertaining said maximum or minimum value in carrying out said analysis means are provided for deliberately varying the mixture strength in a scanning sweep or search performed during intermittent relatively short duration sampling test periods.15« An internal combustion engine as claimed in Claim 14 further characterised in that the second operational parameter v/hich the analyser means is arranged to monitor and analyse is the percentage amount of water in the exhaust gases.16. An internal combustion engine as claimed in Claim 14 and provided v/ith a spark ignition system, further characterised in that the second operational parameter v/hich the analyser means is arranged to monitor and analyse is the firing voltage or build-up time thereof. | BEDFORD T | BEDFORD T; PAYNE N |
WO-1979000531-A1 | 1,979,000,531 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | B25C1 | null | B25C1 | B25C 1/00C, B25C 1/04H | HYDRAULIC NAILING PISTOL | A hydraulic nailing pistol with force or energy-accumulators for reciprocally driving a nail driver (5) formed as a piston with associated piston rod (5). The outer end of the rod is intended for applying to the nail head of the nail to be driven. The piston is arranged in a hydraulic cylinder (26) and the end of the cylinder facing away from the nailing end of the rod is connected, by the intermediary of an openable and closeable valve (3), to a first hydraulic operating cylinder (A) provided with a piston (4), actuable by a force or energy-accumulating component, e.g. a spring (6). The other end of the hydraulic cylinder (26) is connected to a second hydraulic operating cylinder (B), provided with a piston (11), also actuable by a force or energy-accumulating component, e.g. a spring (12). The first operating cylinder (A) with its cylinder (4) is adapted for driving the driver forwards, and the second operating cylinder (B) with its piston (11) is adapted for providing the return movement of the driver (5). By making the pistol in the fashion described, all functions are built into the movable portion of the pistol with simple means, while retaining small dimensions and comfortably low weight, at the same time as the tool develops great power during nailing. | Hydraulic nailing pistolThe invention relates to a hydraulic nailing pistol, the reciprocating move¬ ment of the nail driver being provided by hydraulic operating cylinders, which are equipped with force or energy accumulators. By making the nailing pistol in a manner defined in the accompanying patent claims, all functions are built into the movable part of the pistol with simple means while re-I taining small dimensions and comfortably low weight, the tool developing great power during nailing.An embodiment of a nailing pistol in accordance with the invention is described below in conjunction with the attached drawing, which shows the pistol seen from one side, and partly in section. It should be understood, however, that the invention is not limited only to what is apparent from these embodiments, and many modifications can prevail within the purview of the invention.On the drawing, the numerals refer to the following parts:1 Trigger operated start catch 9 Setting piece2 Operating slide 10 Setting piece .'3 Starting valve 11 Return motion piston . - k Driving piston for nail driver 12 Energy-accumulating spring5 Nail driver 13 Safety spindle6 Energy-accumulating conical h Non-return valve plate spring 13 Locking pin7 Spring 16 Spring8 Setting piece 17 Spring-biassed reel holder, rear 18 Spring-biassed reel holder, forward 26 Hydraulic cylinder19- Feed driving roller 27 Valve port.20 Coupling with safety pin 28 Valve operating piston21 Attache ent ring A Nail driver driving piston22 Cover with springing for B Nail driver return motion nail feed cylinder23 Feed rollers C Nail magazine2k- Linkage for trigger D Reservoir chamber25 Spring P Pressurised liquid inletT Pressurized liquid outletThe pistol functions in the following way:With, the operating slide 2 in the starting position shown on the drawing, ana with pressurized oil connected to the inlet P, the cylinder A is fill with pressurized oil, to compress the energy-accumulating conical plate washers 6. The pistol can now be brought to bear against the workpiece, e a wall, the safety spindle 13 being pressed against the wall when the nai feed driving roller 19 turns the rollers 23 into position under the nail driver 3. ~—-<-- the locking pin 15 is displaced axially against the bias of spring 16, ..releasing the operating slide 2, so that on actuation by the start mechanism 1, 2k it can be moved axially against the bias of the spr 25. -he following measures are thus taken substantially simultaneously: t inlet to the operating cylinder A and the outlet from the reservoir chamb D are closed. Pressurized oil is connected to the driving piston of the valve 3, which will be displaced axially against the bias of the spring 7 so that its port 27 connects the driving cylinder A to the hydraulic cylinder of the nail driver 5- Nailing is now done by action of the drivi piston k in coaction with the expanding energy-accumulating plate springs situated in the driving cylinder A, which force oil against the nail driv piston.The oil on the other side of the nail driver piston is pressurized and forces back the piston 11 in the return motin cylinder B, which is also privided with an energy-accumulating spring 12„ After the driver ~ has executed its nailing movement, the operating slide 2 is unobstructed for returning to the starting position under the action of spring 25, the reservoir chamber D being connected to the outlet T via a port in the slide 2, v/hile the operating cylinder of the valve 3 is also- connected to the out¬ let T via a groove in the spindle, and the driving cylinder A is connected to the inlet P for renewed energy-accumulation by the plate springs 6, en¬ abled by the valve 3 being displaced axially to close off the passage between the operating cylinder A and the hydraulic cylinder 26. The nail ram can now be returned to the starting position with the aid of the press¬ ure oil in the return cylinder B„ V.'hen the nailing pistol is lifted after driving a nail home, the safety spindle 13 and the locking pin 15 return to the starting positio 0 | Claims:1o A hydraulic nailing pistol, characterised in that force or energy-accumulators are arranged for reciprocatingly drivin a naildriver (5), the driver being formed as a piston with associated pis rod (5), with the outer end of the rod being intended for applying to the nail head or the like on the nail to be driven, and in that the piston is arranged in a hydraulic cylinder (26), the end of the cylinder remote fro the nailing end of the rod being connected, with the intermediary of an openable and closeable valve (3), to a first hydraulic operating cylinder (A) provided with a piston (.), said piston being axially movable under t action of a force or energy-accumulating component, e.g. springs (6), whi the other end of the hydraulic cylinder (26) is connected to a second hydraulic operating cylinder (B) provided with a piston (11) which is als axially movable under the action of a force or energy-accumulating compon e.g. a spring (12), the first operating cylinder (A) with its piston (k) ing adapted for driving the nail driver forward, and the second operating cylinder (B) with its piston (11) being adapted for the return move'ment o the nail driver (5).2. A hydraulic nailing pistol as claimed in claim 1, characterised in that the first hydraulic operating cylinder (A) is connected to an openab and closeable inlet (P) for pressurized liquid, and in that the hydraulic cylinder (26), in which the nail driver (5) moves, is connected at its en facing towards the valve (3) to an openable and closeable outlet (T) for pressurized oil, and in that for its operation the valve (3) is provided with a hydraulically actuable piston (28), the cylinder of which is conne ed to the outlet (T) and inlet (P).3. A hydraulic nailing pistol as claimed in claim 1 or 2, characterised in that supply and return of pressurized liquid to the driving cylinder (A) for the nail driver (5) and for the operating cylinder of the valve (3), well as the return oil for the hydraulic cylinder (26), are regulated by means of movable,suitably longitudinary displaceable operating slide (2), which can be actuated by the pistol starting mechanism (1, and which is provided with ports and/or grooves disposed in a first position of the slide (2), so as to connect pressurized liquid to the driving cylinder (A) from an inlet (P), as well as the outlet port at the end of the hydraulic cylinder (26) remote from the nail and the outlet port of the operating cy¬ linder of the valve (3) [to the outlet (TH but in a second position of the slide, after actuation of the starting mechanism (1 , ^), so as to close the inlet to the driving cylinder (A) and the outlet connection to the hydraulic cylinder (D), and connect the inlet (P) to the operating cylinder of the valve (3), whereby the valve (3) opens the passage between the driv¬ ing cylinder (A) and the nail driver (5) for nail driving movement to take placeok. A hydraulic nailing pistol as claimed in any of the preceding claims, characterised in that a safety spindle (13) is so formed and placed that it prevents the re¬ lease of nail driving movement when the pistol start mechanism (1, 2 is actuated, if the pistol is not abutting the workpiece, said spindle suitab¬ ly engaging against a locking pin (15) preventing the displacement of the slide (2) from the starting position before the pistol has been placed - against the workpiece„5o A hydraulic nailing pistol as claimed in any of the preceding claims, characterised in that it is provided with a nail magazine (17, 18, 22, 23) from which one nail at a time is fed into position in front of the nail driver (5), where the magazine can comprise two magazine rollers (23) with magnetic retention of nails accomodated in the magazine, said rollers (23) being turned an angle corresponding to the advance of a new nail under the action of a feed roller (19) driven by the safety spindle (13). advancing a nail alternately from one or other roller (23) into position in front of the nail driver (5).6. A hydraulic nailing pistol as claimed in any of claims 2 - 5» characterised in ■ that after the nail-driving movement has been executed return movements of. valve (3) with its driving piston (28) and the operating slide (2) take place with the aid of compression springs (7 and 25) acting on the respect ive member.Ψ Ϊ X.V.PI_ .To | BILLING L | BILLING L |
WO-1979000532-A1 | 1,979,000,532 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | H01H1 | H01H1, H01H29 | H01H1, H01H51 | H01H 51/28F | MINIATURE MERCURY CONTACT REED SWITCH CONSTRUCTION | A mercury wetted reed switch in which the electrical switch contacts are provided with a geometric configuration which minimizes the amount of magnetic force required to close the switch contacts which are normally open in the absence of a magnetic field and which at the same time provides a quick acting switch for applications which cannot tolerate delays. A first conductive magnetic member (11) is supported by insulating support structure (10) and has a stepped construction provided by a magnetic conductive extension (11b) laterally offset from axial alignment with the rest of the member and extending parallel to the axial direction away from the support. A second conductive magnetic member (13) provides an armature support element supported on the insulating support structure (10) and generally aligned with but separated from the first magnetic member. The second conductive magnetic member also has a stepped construction provided by magnetic conductive extension (13a) laterally offset from the axial alignment to the same side as the extension (11b) of the first conductive member. A magnetic armature member (15) extends between the first and second magnetic members and is of such length and position that it overlaps the axial extending portions of each conductive magnetic member and fits within the step of each without touching. A spring support member (16) connects the armature support element and the armature. The spring support provides a flexible connection which permits the armature to move into improved alignment with the first and second magnetic members to a reluctance minimizing position in the presence of a magnetic field. | DescriptionMiniature Mercury Contact Reed Switch ConstructionBackground of the Invention The present invention relates to a miniature magnetic relay and preferably one of a mercury wetted contact type. In particular, it relates to a reed switch which has sup-erior characteristics over other miniature reed switches of similar size. In the prior art, it has become a practice to provide an offset in the pole piece whereby the end thereof which bears the electrical contact is laterally offset from the axis. The purpose is to afford a configuration of which will minimize the amount o-f magnetic force required to close the switch contacts which are normally open in the absence of a magnetic field. While some improvement has apparently been achieved by this type of construc¬ tion, results have been less than hoped for.Summary of the InventionThe present invention is directed to a device which does minimize the amount of energy required to actuate the reed switch and which at the same time provides a quick acting switch for applications which cannot tolerate delays. More specifically, the present invention involves a reed switch construction which takes maximum advantage of magnetic charac¬ teristics by a novel geometry. More specifically, the present invention concerns a magnetic reed switch having an insulating support structure. A first conductive magnetic member providing a fixed pole is supported by the insulating support structure and provides one switch terminal. The first conductive magnetic member has a stepped construction provided by a magnetic conductive extension laterally offset from axially alignment with the rest of the member and extending parallel to the axial direction away from the support. A second conductive magnetic member provides an armature support element supported on the insulating support structure and generally aligned with but separated from the first magnetic member and provides the other switch terminal. The second conductive magnetic member has a stepped construction provided by magnetic conductive extension laterally offset from the axial alignment to the same side as the extension of the first conductive magnetic member. A magnetic armature member extends between said first and second magnetic members and is of such length and position that it overlaps the axial extending portions of each conductive magnetic member and fits within the step of each without touching. A spring support member connects the armature support element and the armature, and in the absence of a magnetic field in its unstressed condition, positions the armature spaced away from, the first magnetic member. The spring support provides a flexible connection which permits the armature to move into improved alignment with said first and second magnetic members ' to a reluctance minimizing position in the presence of a magnetic field. A conductive contact on the extension of the first conductive magnetic member projecting toward the axis provides an electrical circuit completing contact for the fixed pole and mechanical spacing means limiting the approach of the armature to the magnetic extension. In preferred embodiments of the invention, the insulating support structure is a glass or other insulating envelope and in which mercury is placed which may be evacuated, gas filled and hermetically sealed. The structure is such that the armature and the conductive contact with which it cooperates are wet by the mercury, and the structure is provided with means assuring access of the mercury to the region of the armature opposed to the contact. Preferred EmbodimentFor a better understanding of the present invention reference is made to the accompanying drawings in which:Fig. 1 is a view of a switch of the present invention viewed from that side which enables the showing of the laterally offset extensions of the fixed magnetic conductive members;Fig. la is a separate detail view of similar orientation as Fig. 1 of the inner portion of the armature support member;Fig. lb is a perspective view of the fixed pole element of the structure of Fig. 1;Fig. 2 is a view similar to Fig. 1 but showing the armature in unactuated open contact position; Fig. 3 is a view similar to Fig. 1 of a modified structure in accordance of the present invention;Fig. 3b is perspective view similar to Fig. lb showing the fixed pole piece of Fig. 3;Fig. 4 is a view of the structure of Fig. 3 showing the armature in unactuated open contact position;Fig. 5 is a view showing the contact region of a miniature reed relay of the prior art, and_ΛJ r. liA lT - -_ vP.7_._r.-PoJ_ -y Fig. 6 is a diagramatic view which is actually an axial cross section through the armature and fixed pole extension showing the armature in alternative positions . Referring now to Figs. 1 and 2, the miniature reed switch requires an insulating support structure between the magnetic conductive members. In this case, the insulating support structure is supplied by a glass or ceramic envelope 10 which supports the magnetic conductive member 11 providing a fixed pole which carries conductive contact 12. Spaced from the first magnetic conductive member 11 is a second conductive magnetic member 13 providing an armature support element. As shown, the magnetic armature 15 is connected to the armature support member by resilient spring member 16. * In this case, the armature support member is a tube 13 which is formed as shown in Fig. la so that the actual support of the spring 16 is provided by an elongated ridge or projection 17 across the solid flat surface of 13a. The glass envelope is gas filled through the tube provided by the second conductive magnetic member 13 which then is pinched off and welded as shown in Fig. 1 in order to retain the internal environment. Before the pinching off is done, however, the mercury needed for the switch is introduced through the tubing, and as illustrated in the positions shown, accumulates around the armature support member. Figs, la and lb show some special construction involved in this particular switch. As previously- eluded to, Fig. 1 shows the way in which the tubing member 13, which is sealed through the glass envelope 10, is shaped. As shown, the only cutting of tubing 13 is done across and through to near its center to preserve access to the interior of the enclosureBU RH fa W.i-O when forming the extension 13a by means of compressing magnetic material on both sides to form the projection 17 on one side and to provide a mounting region on the other side for an extension 14 which is flat, laterally offset from the axial line of the conductive magnetic members 11 and 13 but parallel to the axis. As indicated by the stipling in the drawing, the upper part 14a of the extension 14 is provided with a coating which is not readily wet by the mercury 18 while the lower part 14b is left in its natural state which enables it to be wet by the mercury. As indicated, capillary attraction tends to cause mercury to rise in the region between the spring member 16 and the parallel portion 13a of armature support member 13. The armature is designed as shown in Fig. 1 to fit snuggly within the shoulder formed by the extension 14 and portion 13a, and in the closed contact position, shown in Fig. 1, the extension 14 and the armature 15 are close enough to one another to cause the mercury to rise between them by capillary action. The armature 15 itself is preferably provided with capillary grooves which carry mercury upwardly to the region of the contact 12 so as to provide the needed supply of the contact .As shown in Fig. lb, the stationary pole 11 is also provided with the distinctive shape which may be done by swaging its inside end into a flattened area lib offset from but generally parallel to the axis through members 11 and 13. Extension lib is also laterally offset on the same side as extension 14 of the armature support member. In the swaging operation as steep an angle- is -provided as possible to form shoulder 11a. As will be observed, the contact element 12, which is preferably composed of non-magnetic but conductive material may be a mercury non-wettable bar extending from extension lib back toward the axis so that it acts as a stop for the armature 15 or a spacer preventing a closer approach between armature 15 and extension lib than that shown is Fig. 1 only the end of 12 facing 15 is mercury- wettable. The results of the construction is that the armature may be close spaced, over a very long gap in each case, to each of the conductive magnetic members 11 and 13 of which the 11 is not mercury wettable. The proximity of the ends of the armature to the shoulders of members 11 and 13 is also part of the invention. By keeping spacing small in this way, magnetic reluctance is minimized. Yet when a magnetic field is removed, the action of the thin leaf spring immediately returns the armature to the position shown in Fig. 2 separating the contacts. The action of the mercury between the leaf spring and the armature on one hand and the armature support member extension 13a and extension 14 on the other, provides a damping action prevention continued hunting or vibration of the armature. The extension of the armature 14 may be considerable, provided, however, that it is desirable not to have the pool of mercury extend so far as the end of the extension 14 in this case. In order to avoid that the end of 14a of extension 14 is provided with a coating which is not readily wet by mercury, whereas the lower portion 14b of the extension 14 is able to be wet by the mercury. As will be seen, the armature fits, or nests, rather snugly within the fixed magnetic structure. When the magnetic field is applied, parallel close spacing of the armature 15 and extensions lib and 14 is achieved. Contact 12 used as a spacer or a stop and design of positioning spring support 17 and the spring itself make it possible to keep the armature generally parallel and close spaced to the extensions when it engages the stop. Figs. 3 and 4 and Fig. 3b show a modified form of miniature reed switch in accordance with the present invention. The principle difference is in the construction of the extension of the staionary pole piece. In this case, the conductive magnetic element 21 is provided with a shoulder just inside the envelope 10' to which is welded a flat extension 21b as best seen in Fig. 3b. This arrangement has some advantages over the one-piece construction of figs. 1, 2 and lb. One advantage is that the machining necessary to perform the cut-out of the material in member 21 can be combined with cutting the shoulder 21a quite square thus providing somewhat more uniform gradient of magnetic flux through the end of the armature. Another significant advantage is that a separate blade 21b welded in place can be of increased width without sacrificing the overlap area and the thickness of the blade and enables welding more than one contact bar 12 on the end. Such multi contact arrangement with each contract having much smaller mercury wetted end (or area) requires shorter travel of the armature to interrupt the mercury dynamic bridge when opening the conductive contact, thus contributing to the magnetic sensitivity and operating stability of the switch.Also in Fig. 3 and Fig. 4, the extension of the armature support member (13a') is shown as a shorter extension 24 which does not have a non-wettable region corresponding to 14a. If the extension is elongated as in Fig. 1, the non-wettable arrangement is desirable to prevent a flooding of the contact area with mercury. In all other respects, the structure of Figs. 3 and 4 is similar to the structure of Figs. 1 and 2 and corresponding parts are identified with the same number designators with the addition thereto of primes.In general, it will be seen that the switch of the present invention provides increased operational sensitivity at low magnetic force levels by effectively minimizing the magnetic reluctance between the switch components all of which is due to a geometry which permits low magnetic reluctance, both in the open and closed positions as seen in Figs. 2 and 4. The invention not only keeps the magnetic members in relatively close proximity to one another by their geometry, but the extension elements and the armature are preferably all made flat and parallel to one another further lowering reluctance. The diameters of the magnetic conductive elements are also kept at a maximum for the size of the components. On top of this, the dimensions selected in the nesting geometry are such that the armature effectively lies within the shoulders at all times so that the reluctance of the magnetic path is relatively low, even in open contact position. As seen in Fig. 6, for example, the armature 15' and its relation to extension 12' changes somewhat, but in all positions it overlaps the magnetic conductive stationary pole piece 21 and its air gap is extremely small, whether in the open contact position shown in solid lines, or in the closed contact position shown in the dotted lines. The difference in the prior art arrangement now becomes apparent. For in such an arrangement the diameter of the stationary pole was not maximized in the region of the contact area. In the prior art, what might be characterized as an extension provided a limited area overlap of magnetic parts. Thus, the distance of the armature from the stationary pole piece is shown dimensio'nally as a and was substantially greater than that employed in the present invention. Moreover, the connection between the stationary pole piece and its extension was at a rather oblique angle which made the nesting arrangement of the present invention impossible to apply. The thickness of the staionary pole piece c itself was minimal in order to facilitate its support by the envelope and the area of contact overlap b which constituted the magnetic gap was relatively short. Thus, in the prior art was none of the features of the present invention employed or considered to minimize reluctance. The armature nesting feature of the present invention was not possible and overlap occurred really at only one end. Particularly where the armature needs to be hinged by a lightweight spring and non-magnetic material, the extension of the armature support member to parallel the armature as in the present invention is a very desirable reluctance minimizing provision. The problems arising because of extending the extension14 too far can be offset by using chrome oxide or some other coating on the surface of the end of the extension to prevent mercury wetting without losing the magnetic properties of the extension. Minimizing the space between the -extension 14 and the armature15 is primarily a matter of mechanical support for the armature providing that the throw of the armature is not overly great and properly dimensioning the armature support and the ridge carrying the spring. It should be borne in mind that in design of a switch of this sort the holding force of mercury 18 which is moved into the gap between extension 14 and armature 15 may be considerable and must be overcome by the restoring force of the spring 16. Where magnetic materials are placed together as is the case with extension 14 and the armature support member 13 or in the Figs. 3 and 4 construction with extension 21b and the fixed pole piece 21, the reluctance in the joint if carefully made is practically negligable and need not be considered. The effect is further minimized by providing considerable overlap in making the joint which also has mechanically desirable aspects. The free end of the armature 15 is positioned very close to the stationary pole piece 11 even when the contacts are open. The shoulder 11a (or 21a) by being positioned as close as possible to the end of the armature causes a flux concentration which aids in pulling the armature into closed contact position. That is, the gap between the shoulder 11a and the end of the armature 15a is desirably minimized so that in this regard, the structure of Figs. 3 and 4 provide an advantage. In some designs, it may not be possible to make the shoulder 11a as square even as that of_ Fig. 1. It will be understood that some of the advantage is achieved according to the present invention, even if a distinct sharp shoulder is not provided, by keeping the armature as closely bracketed as reasonably possible with a given pole piece shape. All of the features taken together make this miniature switch construction able to operate at unprecedentedly low magnetic field intensity levels. However, the construction also provides very short operating time which tends to remain constant over a long period of time and over a wide operating frequency range. The timing to a large extent is facilitated by keeping selected dimensions extremely small, by keeping the elements of the switch compact and keeping the masses of moving parts very small.The use of the mercury in the switch in practice has proved to be quite advantageous providing a highly desirable* damping effect but without over-damping in any regard. Various modification to the structure of the present invention have been suggested by the disclosure herein. Other modifications will occur to the man skilled in the art. All such modifications within the scope of the claims are intended to be within the scope and spirit of the present invention. | Claims 1. A miniature reed switch comprising: an insulating support structure, a first conductive magnetic member providing a fixed pole supported by the insulating support structure and supporting one switch terminal and having a stepped construction provided by a magnetic conductive extension laterally offset from axial alignment with the rest of the member and extending parallel to the axial direction, a second conductive magnetic member providing an armature support element supported on the insulating support structure and generally aligned with but separated from the first magnetic member, providing the other switch terminal and having a stepped construction provided by a magnetic conductive extension laterally offset from axial alignment to the same side as the extension of the first conductive magnetic member, a magnetic armature member extending between said first and second magnetic members and of such length and position that it overlaps axial extending portions of each conductive magnetic member and fits within the step of each without touching, a spring support member connected between the armature support element and the armature and supporting the armature in a position spaced away from the first conductive magnetic member in the absence of a magnetic field in its unstressed condition and providing a flexible connection which permits the armature to move into improved alignment with said first and second magentic members to a reluctance minimizing position in the presence of a magnetic field, and a conductive contact on the extension of the fixed first conductive magnetic member projecting towar.d .the axis and providing an electrial circuit completing contact for the fixed pole and mechanical spacing meansBUR OV. limiting the approach of the armature to the magnetic extension.2. The miniature reed switch of claim 1 in which the insulating support structure is an insulating envelope enclosing the armature but through which the first and second conductive members extend, a conductive liquid is contained in the envelope and provides a conductor through which the electrical circuit is completed at the contact, and means is provided for supplying liquid to the contact area.3. The reed switch of claim 2 in which the first and second conductive magnetic members are both provided with an approximate right angle step at the extension defining the end bounds of a region closely confining the armature .4. The reed switch of claim 3 in which the spring support member urges the armature to a position adjacent the edge of the step of the first conductive magnetic member so that the armature is thereby close spaced to the fixed pole piece at all times.5. The reed switch of claim 2 in which the conductive liquid is at least in major part mercury and the envelope is at least partially evacuated, and backfilled with gas, one of the magnetic conductive members being a sealed off tube through which exchange of internal environment took place.6. The reed switch of claim 2 in which the extension of the first conductive member is formed of the same piece.BU EAU _O.MPI_ fa \vl7θ _ ~ , 7. The reed switch of claim 6 in which the extension of the first conductive member is formed of a separate piece- fixed with a minimum reluctance joint to the main first conductive member.8. The reed switch of claim 2 in which the conductive contact on the extension of the fixed first conductive member is a member fixed to the end of the extension.9. The reed switch of claim 8 in which the contact is fixed to a face of the extension generally transverse to the axis and overlaps and extends the end of the extension.10. The reed switch of claim 8 in which the contact limits the approach to the armature to such a position that the armature is generally parallel to the extension.11. The reed switch of claim 10 in which the spring support for the armature is fixed to the armature support member near its center and in a position which assures that armature is always close spaced to the step and generally parallel to the extension of the second conductive magnetic member in closed contact position.12. The reed switch of claim 3 in which the structure is attached to the armature support member in such a manner as to provide a capillary path between the spring and support extending to space between the extensio.n and the armature whereby mercury is supplied to the armature to be delivered to the contact area. 13. The reed switch of claim 12 in which the extension to the armature support member is extended beyond the level on the armature desirable as a limit to mercury surface tension forces and possible pumping and is coated with a material which mercury will not wet .14. The reed switch of claim 2 in which the armature support structure is the air evacuation tube which is reduced to approximately its diameter point parallel to the extension in a generally axial step and the armature is support on the structure by a narrow support which spaces the armature from the support member, said armature being connected to the spring to lie on the extension side of the spring just above the step in order to preserve close spacing of the armature and the armature support elements yet provide room for movement. | GORDOS CORP | HORVATH S; LACIS L |
WO-1979000536-A1 | 1,979,000,536 | WO | A1 | XX | 19,790,809 | 1,979 | 20,090,507 | new | B31C13 | C22C33, B65H81 | B22D1, B65H81, C21C7 | B22D 1/00, B65H 81/08, C21C 7/00F | METHOD OF MAKING A FILLED TUBULAR ARTICLE AND ARTICLE MADE THEREBY | A method of making a filled tubular article (12) for controlled insertion into a molten metal includes extending a treating material (24) through an apparatus (14) to form an elongated core element (16) and wrapping the core element (16) in a protective casing (20). preferably, the casing (20) of the article (12) includes a helically wrapped ribbon-like strip (52). | DescriptionMethod of Making a Filled Tubular Article and Article Made TherebyTechnical Field The present invention relates to a method of making a filled tubular article for controlled inser¬ tion into a molten metal as it is being cast, and to the article made thereby. Background Art The addition of alloying and treating agents into a molten metal such as iron, by insertion of an elongated rod-like article into a casting mold's down- sprue is becoming more well known in the art. More sophisticated methods and apparatuses have recently been developed to controllably insert filled tubular- articles into the casting molds during metal pouring at exactly the rate and point required to obtain the desired castings. These elongated articles usually have a core of powdered ingredients or particulate material carried in a protecting tube. As far as is known, such articles are manufactured by depositing the powdered ingredients onto a strip of metal that may be partly formed into a trough. The strip is thereafter formed into a tube by conventional methods with the edges either abutting or overlapping. Unfor¬ tunately, a major problem is experienced at this point because the ingredients of the core are not sufficiently densified within the tube which results in the powder tending to separate and move within the tube. Conse- quently, it has been fo nd necessary to pass the tube axially through a forming die which reduces its exter¬ nal diameter and compacts the powdered ingredients. Even with this extra step it is a frequent practice to*U EΛOMPI crimp or pinch the ends of the tubes to keep the par- ticulate material from falling out. Such crimping practice is also used for retaining powder in an alternate construction embodying short stiff tubes which are filled with powder after the tubes are made. Not only are the aforementioned manufactur¬ ing procedures for making the filled tubes complica¬ ted, but also it has been found that the thickness of the tubes is often excessive or irregular, and therefore the volumetric ratio or proportion of the core material to the entire article is dispropor¬ tionately low. For example, if attempts are. made to make the radial thickness of the metal tubes below approximately 0.25 mm with current technology then the edges of the tubes generally fail to remain in abutment and this allows powder to fall out. On the other hand, if the tube edges are overlapped, when the rod is inserted into a molten bath the melting rate around its periphery is unequal. Because of the relatively poor dissolution or melting rate of the relatively thick prior art tubes, the rate of feeding them into the molten bath has necessarily been reduced in order to prevent the unmelted and excessively stiff remaining portions of the tubes from penetrating the sides of the casting mold's downsprue.In view of the above, it would be advan¬ tageous to replace the relatively thick and non- uniform prior art tubes with a thinner casing, and yet retain a relatively high degree of uniformly dense fill material within the core.Disclosure of Invention.The present invention is directed to over¬ coming one or more of the problems as set forth above.-BUO In accordance with one aspect of the pre¬ sent invention, this is accomplished by extruding a treating material to form an elongated core element and by helically wrapping the extruded core element in a protective casing to form a filled tubular article. Advantageously, the core element is of uniformly consolidated density and the casing is thin so that the article is flexible and the casing will experience' a relatively rapid rate of dissolu- tion in the molten bath. Furthermore, the instant invention will provide increased core volume per - unit length.In accordance with another aspect of the invention the filled tubular article for altering molten metal includes an elongated core element having a particulate mixture of a treating agent and a binding agent consolidated in a range of about 85 to 95% theoretical density-, the treating agent comprising about 90 wt.% or more of the core element and the binding agent about 1 to nor more than 10 wt.% of the core element, and a casing helic¬ ally wrapped about the core element and substantially covering the entire exterior surface thereof.Brief Description of the Drawings FIG. 1 is a diagrammatic side elevational view of a manufacturing facility illustrative of the method of making the filled tubular article in accor¬ dance with one embodiment of the present invention. FIG. 2 is a diagrammatic and enlarged fragmentary view of one embodiment of the filled tubular article of the present invention made by the manufacturing facility of FIG..1FIG. 3 is a view similar- to FIG. 2, only showing a second embodiment filled tubular article with an overlapped form of exterior casing. FIG. 4 is an enlarged and fragmentary dia¬ grammatic side elevational view of a third embodi¬ ment filled tubular article showing two layers of exterior casing.Best Mode For Carrying Out The InventionReferring to FIG. 1, a manufacturing facil¬ ity 10 is shown for making an improved filled tubular article 12 in accordance with the present invention. In its simplest form, the manufacturing facility con- templates use of an extruding apparatus or press 14 - for making an elongated core element 16, and use of a rotatable wrapping device 18 for applying a helic¬ ally wrapped casing 20 encirclingly about the core element. The exemplary tubular article thus produced is shown in FIG. 2.More particularly, the extruding apparatus 14 preferably includes a feed hopper 22 in which a substantially homogenous mixture of a treating material 24 has been placed. Through gravity, the treating material travels downwardly to be received within the internal, mechanism of the extruding ap¬ paratus or press. As is well known, however, such presses are constructed so as to extrude the treating material 24 under considerable pressure, and often while simultaneously heating the treating material, through an outlet die 26 having a horizontal axis 27 and a suitable orifice of preselected dimensions con¬ centrically disposed on the axis, not shown. Prefer¬ ably, the core element 16 extends axially from the orifice of the die in the form of a continuously elongating cylindrical rod.It should be-appreciated that. the core element 16 is normally in a green state after passing axially outwardly of the die, or to the right when viewing the drawing, and is generally capableOM of experiencing only a relatively limited amount of flexing without cracking. It is contemplated that the extruded core element includes a relatively com¬ pacted mixture of a particulate treating agent or plurality of inoculating elements 28 and a suitable binding or bonding agent 30 as generally indicated in FIG. 2, and may include other additives as well. The term treating agent as used herein includes the element or elements which actually alter the molten metal so that upon cooling and hardening thereof into an article, the articles metallurgical structure has the desired modified physical proper¬ ties. The type of treating agent 28 utilized is dependent upon the base composition of the molten metal to be treated and upon the desired metallur¬ gical characteristics of the article. For example, for treating iron, the treating agent consists essentially of a plurality of ferrosilicon based particles capable of passing through a fine mesh sieve such as between Standard Test Sieve Nos. 30 to 140 (0.6 mm - 0.1 mm nominal diameter of the openings) . Three examples of such treating agents, for iron are set forth below in percentage by weight: Example 1 Example 2 Example 3 Si 74-79% Si 60-65% Si 44-48% Al 1.00-1.5% Mn 5-7% Mg 8-10%Ca 0.50-1.00% Zn 5-7% Fe balance Fe balance Ba 2-3%Ca 1.5-2.5% Al 0.75-1.25%Fe balance Example 1 above is identified as Grade 75% ferrosilicon. ,- Example -2- is identified as SMZ- - Alloy and Example 3 is identified as 9% magnesium ferrosilicon , all of which are manufactured by Union Carbide Corporation, Ferro-Alloys Division, Buffalo, New York. **■ As noted in the above examples, the treating agents 28 normally contain small portions of one or more additional elements in addition to the ferrosilicon constituent such as aluminum, calcium, manganese, zir- conium, barium, magnesium, strontium, cerium, and the rare earth elements.The term binding agent as used herein in¬ cludes the resinous or cement-like material that is used to hold the particles of the treating agent together. Preferably, the binding agent 30 is selected from the group consisting of beeswax, sodium silicate, resin, casein, and organiz plastic material including poly- urethane. The amount of binding agent is preferably limited to a preselected range of from about 1 to not more than 10% of the weight of the core element 16. Enough binding agent is needed to allow proper ex¬ trusion of the core element and to maintain its shape. Too much binding agent, for example above 10%, will form a slug or will alternately lead to other pro- blems such as producing an excessive amount of flames and- bubbling reaction as the filled tubular article 12 is inserted into molten iron.In addition to the treating agent 28 and the binding agent 30, it is contemplated that a lubricating or slipping agent 31 may be advantageous in forming the core element 16. Particularly, a relatively low pro¬ portion of a lubricating agent such as graphite or zinc stearate may be helpful during the extrusion of the mixture 24 through the die 26. However, it should be understood that the treating agent preferably makes up about 90% or more of the total weight of the treating material making up the core element, the binding agent makes up about 1 to not /more than 10% of the weight . of the core element, and the lubricating agent makes up about 0.3 to 2% of the weight of the core element.-βURO It is contemplated that the core element 16 is compacted to a relatively dense state by the ex¬ trusion press 14, and experiences minimal swelling after passing axially outwardly of the die 26. For example, the density of the consolidated core element is preferably in a preselected range of about 85% to 95% theoretical density, which is substantially equi¬ valent to having only about 5% to 15% volume in voids. Despite the substantial consolidation of the extruded core element* 16, it is to be appreciated that it is advantageous to continue its rightward movement ' along the axis 27 with but minor angular deviation to avoid abrupt flexing of the core element prior to the encasement thereof. Consequently, one or more sup- port rollers 32 and one or more stationary guiding members 33 are preferably utilized for this purpose. Preferably also, a combined traction and support means . 34 is located downstream of the extrusion press 14 to bias or urge the core element to the right when viewing the drawing. A pair of powered endless belts 36 and 38 disposed immediately above and below the core ele¬ ment may be used for this purpose.Referring now to the wrapping device 18, it includes a support stand 40 and a rotary mechanism 42 which is controllably revolved about a central hori¬ zontal axis 44. Preferably, the axis 44 is in substan¬ tial alignment with the axis 27. At least one cylin¬ drical reel 46 is located on a frame member 48 of the mechanism, which reel is generally revolvable in use in a counterclockwise direction when viewing the drawing about an axis 50. A ribbon-like strip 52 extends substantially axially from its stored position on the reel and to a tension monitoring unit 54; - From there the strip extends through a guide 56 and obliquely onto the elongating core element 16. Preferably, the ribbon-like strip 52 is rela¬ tively thin; for example, within a range of about 0.025 mm to 0.15 mm and preferably about 0.1 mm thick, and is helically wrapped about the core element 16 with its opposite side edges 58 and 60 disposed in aligned axial abutment with the facing side edges of the ad¬ jacent loop as shown in FIG. 2. It is contemplated that the strip is preferably a metal foil selected from the group consisting of a ferrous metal such as steel, aluminum, titanium, copper, and alloys thereof. However, it is to be appreciated that a strip of organic material such as of plastic or fibrous paper composition may be substituted for such metal foil without departing from the spirit of the present invention. After the strip 52 is helically wound about the core element 16, the filled tubular article 12 is urged rightwardly by a powerably rotated cylindrical take-up reel 62 and an associated drive motor 64. The improved filled tubular article produced in this manner and wound on the reel, which is releasable from the motor and a support stand 66, is subsequently control- lably inserted into molten metal for altering the metallurgical structure of the melt upon cooling and hardening thereof in a .casting mold. Such a procedure is disclosed, for example, in more detail in U.S. Patent No. 3,991,808 issued to John R. Nieman, et al on November 16, 1976.Referring to FIG. 3, an alternate embodiment is shown wherein the various elements of the filled tubular article 12 are the same and, accordingly, similar reference numerals have been applied thereto. However, in the alternate* embodiment, the ribbon-like strip 52 has been wound about the core element 16 by the manufacturing facility 10 in such a way that the edges 58 and 60 axially overlap and provide more positive assurance of retention of any inadvertently loose particles of the core element 16. While this provides the disadvantage of a double thickness of the adjacent loops of the strip at the point of overlap, it is to be recognized that such double thickness is still about 30% or more less than the total thickness of the thinnest practical prior art casing.A more sophisticated embodiment is shown in FIG. 4, wherein the core element 16 and casing 20 are substantially as described above with reference to FIG. 2. However, in this example a second layer or -casing 68 has been applied over the casing 20. The second casing includes a second, continuous ribbon¬ like strip 70 which is advantageously oriented at a different angle of orientation than the first strip 52 relative to the core element as indicated generally on the drawing by the reference letters A and B. Pre¬ ferably, the first and second strips are sequentially and helically wound about the core element from opposite directions as is clearly shown. The dual layer casing is stronger and has a reduced tendency to unwind. Specifically, a single helically wound strip has a ten¬ dency to exhibit a resistance to coiling and a tendency to open up between adjacent loops if forcibly coiled incorrectly. Another wrapping device 18, not shown, would be required to provide the second layer of casing in any continuous extension of the manufacturing facility 10. Such second wrapping device would be located axially intermediate the first wrapping device and the take-up reel 62.Industrial ApplicabilityIn view, .of ther .forsg.oing, it_ is readily appar¬ ent that the method of the present invention provides an improved filled tubular article useful for controlled insertion into a molten metal. Rather than simply filling a tube with loose particulate material as has been done in the past, the manufacturing facility 10 contemplates the following sequential procedure: Step (a) mixing a particulate treating agent and a binding agent to form a treating material.Step (b) feeding the treating material to an extruding apparatus;Step (c) extruding the treating material, optionally in the presence of heat, through a die to form an elongated core element;Step (d) helically wrapping the extruding core element in a protective casing; andStep (e) rolling up the encased core onto a take-up reel.Moreover, the above described procedure may be extended to helically wrapping the core element in various ways, including helically wrapping a second layer onto a first layer by an additional wrapping step. Still further, the instant manufacturing facility is easily adapted to overlappingly winding one ribbon-like strip or a plurality of such strips about the core element.Other aspects, objects and advantages will become apparent from a study of the specification, drawings and appended claims.. /' | Claims1. A method of making a filled tubular article (12) for controlled insertion into a molten metal for altering same, comprising:Step (a) extruding a treating material (24) to form an elongated core element (16) ; andStep (b) helically wrapping said extruded core element (16) in a protective casing (20) .2. The method of claim 2 wherein step (b) includes overlappingly winding a ribbon-like strip (52) about said core element (16)3. The method of claim 1 including the step of mixing a particulate treating agent (28) with a binding agent (30) and forming said treating material(24) prior to Step (a) .4. The method of claim 1 including the step of mixing a particulate treating agent (68) , a binding agent (30) and a lubricating agent (31) and forming said treating material (24) prior to Step (a) .5. The method of claim 1 including maintaining continuous movement of said core element (16) during steps (a) and (b) .6. The method of claim 1 wherein Step (b) in¬ cludes helically wrapping the elongated core element (16) by a rotatable wrapping device (18) ; and including supporting and guiding said elongated core element (16) between the extruding apparatus (14)- and the wrapping device (18) . 7. The method of claim 1 including heating the treating material (24) prior to Step (a) .8. A filled tubular article (12) for con¬ trolled insertion into a molten metal for altering same, comprising: elongated core element means (16) for treating the molten metal, said core element means (16) in¬ cluding a particulate mixture of a treating agent (28) and a binding agent (30) consolidated in a preselected range of about 85% to 95% theoretical density, said treating agent (28) comprising about 90% or more of the total weight of said core element means (16) and said binding agent (30) comprising about 1% to not more than 10% of the total weight of said core element means (16) ; and casing means (20) for substantially covering the entire exterior surface of said core element means (16) and containing said core element means (16) , said casing means (20) being intimately and helically wrapped about said core element means (16) .9. The article (12) of claim 8 wherein said binding agent (30) is selected from the group consisting of beeswax, sodium silicate, resin, casein, and organic plastic material including polyurethane.10. The article (12) of claim 8 wherein said casing means (20) includes a ribbon-like strip (52) of metal selected from the group consisting of a ferrous metal, aluminum, titanium, copper, and alloys thereof.11. The article (12) of claim-8 vherein said core element means (16) further includes a lubricating agent (31) comprising about 0.3% to 2% of the total weight of said core element means (16) .OMPI 12. The article (12) of claim 11 wherein said lubricating agent (31) is zinc stearate. | CATERPILLAR TRACTOR CO | NIEMAN J; SANDERS S |
Subsets and Splits