Abstract:
A system for dispensing a quantity of a coating material is disclosed. The system includes a dispensing head assembly maneuverable over a target object, and a purge cup operatively positioned relative to the dispensing head assembly. The purge cup defines a cavity for receiving a quantity of a solvent therein, wherein a nozzle of the dispensing head is positioned in the cavity of the purge cup when the system is in an idle condition.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 60/519,181, filed on Nov. 11, 2003, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND  
       [0002]     1. Technical Field  
         [0003]     The present disclosure relates to spray head applicators, dispensing systems, and methods for selective application of materials to objects and, more particularly, to spray head applicators, dispensing systems, and methods for use in applying a selected coating to a tray of surgical-type needles.  
         [0004]     2. Background of Related Art  
         [0005]     Spraying may be one of the most commonly used methods employed in applying coatings of material to surgical needles. Spraying can be categorized as either air spraying in which an air stream is impinged against a stream of liquid coating material after leaving the spray nozzle to form an atomized spray pattern, or airless spraying in which the coating material is dispensed as a nonatomized spray pattern.  
         [0006]     An important factor in spray coating is the amount or quantity of coating material dispensed onto the target material, e.g., trays of surgical-type needles and the like.  
         [0007]     Accordingly, a continuing need exists for improvements in spray head applicators, dispensing systems and methods of using the same.  
       SUMMARY  
       [0008]     Methods of fabricating surgical-type needles are disclosed. Systems for dispensing a quantity of a coating material are disclosed. According to one aspect of the present disclosure, a system for dispensing a quantity of a coating material includes a dispensing head assembly maneuverable over a target object, and a purge cup operatively positioned relative to the dispensing head assembly. The purge cup defines a cavity for receiving a quantity of a solvent therein, wherein a nozzle of the dispensing head is positioned in the cavity of the purge cup when the system is in an idle condition.  
         [0009]     It is envisioned that the dispensing system includes a supply of coating material operatively associated with the dispensing head assembly. Preferably, the coating material can include a silicone based coating material including and not limited to a coating mixture comprising at least one polydialkylsiloxane having a molecular weight of at least about 10,000 cp and at least one other siliconization material (e.g., aminoalkyl siloxane and at least one other siloxane copolymerizable therewith, polydimethylsiloxane having amino and alkoxy functional groups).  
         [0010]     It is further envisioned that the dispensing system includes a gravity feed system for determining the amount and/or quantity of the coating material to be dispensed to the target object. The gravity feed system includes a scale for supporting the supply of coating material. The amount and/or quantity of the coating material to be dispensed can be calculated from the decrease in weight of supply of coating material. Preferably, the gravity feed system can be calibrated to dispense about 19 grams of coating material for a target object including a plurality of surgical needles each having a thickness of 0.012 to about 0.067 inches. In addition, the gravity feed system can be calibrated to dispense about 16 grams of coating material for a target object including a plurality of surgical needles each having a thickness of about 0.006 to about 0.011 inches.  
         [0011]     The gravity feed system can include a scale for measuring the decrease in the weight of the supply of coating material. An algorithm can be provided to convert the loss in weight of the supply of coating material to the quantity of coating material dispensed.  
         [0012]     It is envisioned that the target object includes a plurality of needles and/or a tray having a plurality of needles connected thereto.  
         [0013]     It is envisioned that a conveyor can be provided to carry the target object thereon. It is further envisioned that a hood can be provided to surround the target object during the dispensing of the coating material.  
         [0014]     Desirably, a solvent is disposed in the cavity of the purge cup. The solvent is of the type for inhibiting clogging of a distal end of the dispensing head assembly when the distal end of the dispensing head assembly is disposed in the solvent contained in the purge cup.  
         [0015]     According to another aspect of the present disclosure, a method of coating a target object is provided. The method of coating of the target object includes providing a dispensing system including a dispensing head assembly, a supply of coating material operatively connected to the dispensing head assembly, and a purge cup containing a quantity of a solvent therein and for retaining a portion of the dispensing head assembly therein when the dispensing system is idle.  
         [0016]     The method further includes the steps of removing the dispensing head assembly from the solvent of the purge cup, positioning the dispensing head assembly over a target object, dispensing a predetermined quantity of coating material onto the target object, maneuvering the dispensing head assembly over the target object in a predetermined pattern, and returning the dispensing head assembly to the purge cup such that a distal end portion of the dispensing head assembly is submerged below the surface of the solvent.  
         [0017]     The method can further include the step of the gravity feed system terminating the dispensing of the coating material after a predetermined amount of coating material has been dispensed. The gravity feed system can include a scale for measuring the decrease in the weight of the supply of coating material. An algorithm can be provided to convert the loss in weight of the supply of coating material to the quantity of coating material dispensed. Accordingly, the method can further include the step of transmitting a “no go” signal, from the gravity feed system to the dispensing system, when the predetermined quantity of coating material has been dispensed, to terminate the dispensing of the coating material.  
         [0018]     According to another aspect of the present disclosure, a dispensing system for dispensing a quantity of a coating material, is disclosed. The dispensing system includes a dispensing head assembly having a sleeve defining a material supply passageway to receive the coating material; an inner barrel disposed within the sleeve and defining an air passageway between the sleeve and the inner barrel; and a nozzle operatively supported on a distal end of the sleeve in a fluid tight manner, the nozzle having an orifice through which coating material from the supply passageway is dispensed, the nozzle having an annular flange with air ports formed therein and in fluid communication with the air passageway. The dispensing system further includes a reservoir for containing a supply of coating material fluidly connected to the dispensing head assembly; and a gravity feed system including a scale for supporting the supply of coating material, wherein the gravity feed system determines the quantity of coating material dispensed from the dispensing head assembly.  
         [0019]     The dispensing system may further include a purge cup including a solvent material therein. Accordingly, in use, the nozzle is disposed within the solvent of the purge cup when the dispensing head assembly is idle. The solvent material desirably reduces the exposure of the nozzle to ambient moisture and minimizes silicon cross linking of the coating material.  
         [0020]     The gravity feed system desirably includes a cut-off circuit for regulating the quantity of coating material dispensed from the reservoir. The cut-off circuit transmits a “go” signal when coating material is to be dispensed and a “no go” signal when coating material is not to be dispensed. The cut-off circuit desirably monitors the scale during dispensing of the coating material from the reservoir. As such, when the scale reaches a threshold level, the cut-off circuit transmits a “no go” signal and terminates dispensing of the coating material from the reservoir.  
         [0021]     Desirably, the solvent is at least one of a hydrocarbon solvent of from about 5 to about 10 carbon atoms, an alcohol, a hexane, a heptane, and an isopropanol.  
         [0022]     These and other aspects and advantages of the present disclosure will be apparent to those skilled in the art from the following description of the preferred embodiments in view of the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     The structure, operation, and advantages of the presently preferred embodiment of the disclosure will become further apparent upon consideration of the following description taken in conjunction with the accompanying drawings, wherein:  
         [0024]      FIG. 1  is a side view of a prior art dispensing head assembly, suitable for use with the present disclosure;  
         [0025]      FIG. 2  is a longitudinal cross-sectional view of the dispensing head assembly of  FIG. 1  as taken along line A-A of  FIG. 1 ;  
         [0026]      FIG. 3  is an enlarged side elevational view of the indicated area of  FIG. 2 ;  
         [0027]      FIGS. 4A and 4B  are enlarged cross-sectional side elevational views of the distal end of the dispensing head assembly of  FIGS. 1 and 2 , illustrating the dispensing head assembly in an unassembled ( FIG. 4A ) and an assembled condition ( FIG. 4B );  
         [0028]      FIG. 5  is a schematic perspective view of a dispensing system in accordance with an embodiment of the present disclosure using the dispensing head assembly of  FIGS. 1 and 2 ;  
         [0029]      FIG. 6  is a diagrammatic view illustrating use and/or operation of the dispensing system of  FIG. 5 ; and  
         [0030]      FIG. 7  is an enlarged perspective view of the dispensing head assembly of dispensing system of  FIGS. 5 and 6  disposed in a purge cup. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0031]     Preferred embodiments of the presently disclosed spray head applicator, dispensing systems and methods of use will now be described with reference to the drawing figures wherein like reference numerals identify similar or identical elements. In the drawings and in the following description, the term “proximal”, as is traditional, will refer to the end of the element which is closer to the operator, while the term “distal” will refer to the end of the apparatus which is further away from the operator.  
         [0032]     With reference to  FIGS. 1-4B , a prior art dispensing head assembly  10 , for use with a dispensing system, is illustrated such as can be used with the concepts of the present disclosure. In general, dispensing head assembly  10  is operatively connected to a supply of air “P” in order to be able to effect an air assisted spray pattern. The design and specific operation of dispensing head assembly  10  is fully described in U.S. Pat. No. 6,244,522, the entire contents of which are incorporated herein by reference.  
         [0033]     Dispensing head assembly  10  includes a main dispenser body  12  which, at a first end  13  thereof, has a valve plunger return and adjustment mechanism  14  mounted thereto. Dispensing head assembly  10  further includes a barrel assembly  18  including a sleeve  20  that is mounted to the main body  12 , opposite the first end  13 . The barrel assembly  18  includes a nozzle and nozzle seat, as well as inner and outer barrels or tubes, as will be further explained in connection with  FIG. 2 .  
         [0034]     With reference next to  FIG. 2 , the dispensing head assembly  10  is shown in longitudinal cross-section. For clarity, a manifold for connecting the dispensing head assembly  10  to a source of coating material and to a source of pressurized air for actuating plunger mechanism  14  is omitted from the drawings herein. For a detailed discussion of the manifold, reference can be made to U.S. Pat. No. 5,336,320, the entire contents of which are incorporated herein by reference.  
         [0035]     For purposes of the present disclosure, it is sufficient to note that the coating material is introduced into dispensing head assembly  10  via an inlet port  24 , and actuating pressurized air is introduced into mechanism  14  via an air port  26 . The coating material passes into a cavity  25  and then down into a feed bore as will be described hereinafter. A supply hose “A” is connected at one end to port  24  by any suitable fitting (not shown), as is well known in the art, and at the other end to a supply “B” of the material being dispensed (i.e., the coating material).  
         [0036]     With continued reference to  FIG. 2 , sleeve  20  of barrel assembly  18  includes a flange  28  for mounting sleeve  20  onto main body  12  via bolts  22 . Sleeve  20  has a central bore  30  that receives a first end ( 32   a ) of a first or inner barrel or material feed tube  32 . Inner barrel  32  slides up into sleeve  20  and bottoms on a counterbore shoulder  34  thereof. Inner barrel  32  extends to an opposite nozzle seat end  32   b.    
         [0037]     With reference also to  FIG. 3 , nozzle end  32   b  of inner barrel  32  has a nozzle seat recess  36  formed therein. Recess  36  is in the form of a counterbore, however, for example, barrel  32  can be provided with any configuration that is suitable for retaining a nozzle seat, or the seat could be integrally formed therewith.  
         [0038]     Dispensing head assembly  10  can include a two piece nozzle assembly  40 . Nozzle assembly  40  includes a nozzle seat  42  and a discharge nozzle  44 . Nozzle seat  42  is received in recess  36  and is inserted until seat  42  engages a shoulder  46  where it is brazed or otherwise secured in place.  
         [0039]     With additional reference to  FIG. 4A , nozzle seat  42  is generally a cylindrical structure with an inwardly extending seat wall  48  having a central flow port  50  formed therethrough. Port  50  is opened and closed by a valve member  52 , which can be realized in the form of a ball tip carried at an end of a valve plunger  54 .  
         [0040]     Plunger  54  is disposed within a central feed bore  56  of inner barrel  32 . Plunger  54  is appropriately dimensioned so that there is sufficient space for coating material to flow from cavity  25 , down barrel  32  to nozzle assembly  40 . The coating material thus flows down inner barrel  32  through bore  56  along outside of plunger  54 . When plunger  54  is retracted (not shown), the ball tip of valve member  52  unseats from seat wall  48  to open port  50 , thus permitting material to flow through port  50  to the discharge nozzle  44 .  
         [0041]     With continued reference to  FIGS. 2 and 4 A, nozzle seat  42  includes a cylindrical extension  60  with a counterbore recess  62  formed therein. Recess  62  closely receives a central annular nozzle body stem  70  of discharge nozzle  44 . Stem  70  has a seal groove  72  formed therein. A seal  74  is disposed on stem  70  in groove  72 . Seal  74  preferably is retained within groove  72  sufficiently so as not to be dislodged when nozzle stem  70  is inserted into nozzle seat recess  62 .  
         [0042]     Discharge nozzle  44  further includes a tapered central tip  76  through which material is dispensed toward a target. A central dispensing bore  78  extends through nozzle  44  from stem  70  to tip  76 . Material flowing from port  50 , when valve  52  opens, is thus discharged through an outlet spray orifice  80 .  
         [0043]     Nozzle  44  also includes air jets  82  formed in an annular flange  84 . Air jets  82  may be realized in the form of individual bores formed through flange  84  as illustrated. Preferably, jets  82  are precisely angled so as to direct air towards the material exiting orifice  80  to impart a swirling motion to the material flow pattern. This swirling motion is in the nature of a tornadic swirling motion to effect a thorough yet highly selective and controlled application of the conformal coating material on the target. Jets  82  are radially disposed outward of seat extension  60  so as to be open to a cavity that surrounds the outside of nozzle seat  42  as will be further described hereinafter.  
         [0044]      FIG. 4B  illustrates nozzle  44  fully inserted and seated in nozzle seat  42 . Seal  74  effectively seals against material escaping from nozzle assembly  40  around stem  70 , and also prevents air from passing up into feed bore  56 . In other words, seal  74  separates the fluid material section or bore  56  from the air section or passage  92 . Preferably, but not necessarily, flange  84  bottoms against lower wall  60   a  of seat extension  60  before stem  70  upper wall  70   a  bottoms against lower wall surface  48   a  of seat wall  48 . Nozzle  44  can be inserted into seat  42  by pushing nozzle  44  up into recess  62  with a slight twisting motion. Seat extension  60  may be chamfered as at  60   b  to help guide the nozzle stem  70  into recess  62  and to reduce the occurrence of damaging seal  74  during assembly.  
         [0045]     With reference again to  FIGS. 2 and 3 , an outer barrel or tube  86  is generally concentrically disposed about inner barrel  32  and nozzle assembly  40 . Outer barrel  86  includes an internally threaded tubular end  88  that is screwed onto an externally threaded end  20   a  of the sleeve  20 . An O-ring  90  or other suitable sealing technique is used to seal this joint against loss of pressurized air.  
         [0046]     Outer barrel  86  is appropriately sized so as to provide an air passage  92  between inner wall  86   a  of barrel  86  and outer wall  94  of inner barrel  32 . Spacers  96  may be used in this air passage  92  to maintain concentric alignment of barrels  32 ,  86  along the axial extent thereof. Spacers  96  can also be used to impart a turbulent or swirling motion to the air flow.  
         [0047]     Air passage  92  is an annulus that is in fluid communication with an air inlet port  98  that is coupled to an air inlet fitting  100 . Fitting  100  connects with a conduit  102 , e.g., an air hose, to feed air from pressurized air supply “P” to air passage  92 .  
         [0048]     Air passage  92  opens to a preferably but not necessarily enlarged air cavity  108 . Air jets  82  also open to cavity  108 . Valve seat  42  may be tapered as at  110  ( FIG. 4A ) to provide this enlarged air cavity. Jets  82  are preferably angled downward and radially to produce a rotating air pattern around discharge orifice  80 . As the fluid that is dispensed from nozzle  40  enters the tornadic rotating air pattern, the fluid swirls and rotates to produce a desired spray pattern including a swirling atomized fluid spray pattern or a swirling monofilament fluid pattern  
         [0049]     As illustrated in  FIGS. 2 and 3 , the nozzle end of outer barrel  86  has an inwardly extending shoulder or flange  106 . Flange  106  engages flange  84  of nozzle  42  and securely holds nozzle  42  in place after outer barrel  86  is fully threaded and tightened down onto sleeve  20 . The radial extent of outer barrel flange  106  is limited in order to prevent obstruction of air jets  82  and to prevent interference with the swirling air flow.  
         [0050]     Turning now to  FIGS. 5 and 6 , a dispensing system  200  and a method of use of the same, in accordance with an embodiment of the present disclosure, will be described. Dispensing system  200  includes a dispensing head assembly  210 , substantially similar to dispensing head assembly  10  described above, a reservoir or supply  220  of coating material “C” operatively connected to dispensing head assembly  210  (by, for example, a conduit  222 ), a source of pressurized air “P” operatively connected to dispensing head assembly  210 , and a purge cup  230 , containing a quantity of a solvent “S” therein, positioned in close proximity to a target site “T”.  
         [0051]     Dispensing system  200  is configured and adapted to provide a tray of surgical needles  240 , including a tree of surgical needles  242  or a plurality of individual needles (not shown), with a coating of material “C”. While the present disclosure illustrates and describes, in the interest of brevity, the use of dispensing system  200  on trays of surgical needles  240 , it is envisioned and within the scope of the present disclosure for dispensing system  200  to be used, equally as well, on other types of suture needle productions or other types of applications.  
         [0052]     Coating material “C” can include and is not limited to silicone based coating materials including a coating mixture comprising at least one polydialkylsiloxane having a molecular weight of at least about 10,000 cp and at least one other siliconization material (e.g., aminoalkyl siloxane and at least one other siloxane copolymerizable therewith, polydimethylsiloxane having amino and alkoxy functional groups). Other suitable coating materials are disclosed in U.S. patent appln. Ser. No. 09/964,901 filed on Sep. 27, 2001, entitled “Siliconized Surgical Needles and Methods for Their Manufacture”, the entire contents of which are incorporated herein by reference.  
         [0053]     The amount of coating material “C” sprayed onto tray of needles  240  is determined by using a gravity feed system  300 . Gravity feed system  300  includes a scale  302 , on which supply  220  of coating material “C” is placed, and, optionally, an automated interface or computer  304  operatively connected with scale  302  for displaying the quantity of coating material “C” dispensed by dispensing system  200 , for performing various algorithms, permutations, calculations and the like. Use and operation of gravity feed system  300  will be described in greater detail below.  
         [0054]     Depending on the gauge and/or dimensions of the needles (e.g., wire sizes) to be coated and/or the thickness of the coating material “C” to be provided, gravity feed system  300  is calibrated and/or otherwise configured to dispense various quantities of the coating material “C” onto tray of needles  240 . By way of example only, for a tray of needles having wire sizes of between about 0.012 to about 0.067 inches it is preferred that about 19 grams of coating material “C” is dispensed over the tray of needles, and for a tray of needles having wire sizes of between about 0.006 to about 0.011 inches it is preferred that about 16 grams of coating material “C” is dispensed over the tray of needles.  
         [0055]     Gravity feed system  300  functions pursuant to lost volume and/or lost mass principles. In other words, in use, scale  302  is initially set to zero and as coating material “C” is dispensed from supply  220  of coating material “C”, the weight of supply  220  is decreased by a quantifiable amount. Then, using known formulas, algorithms and calculations, the quantifiable amount of decrease in the weight of supply  220  is then used to calculate the total grams of coating material “C” being dispensed from dispensing system  200 .  
         [0056]     Preferably, the total grams of coating material “C” dispensed onto the tray of needles is displayed on interface  304 . More preferably, gravity feed system  300  can be provided with an automatic cut-off circuit or computer program  306  for regulating when to dispense coating material “C”. For example, in use, when scale  302  is originally “zeroed”, dispensing system  200  receives a “go” signal from computer program  306  thereby allowing for coating material “C” to be dispensed. Computer program  306  monitors the decrease in the weight of supply  220  such that when the weight of supply  220  is reduced by a threshold amount (e.g., corresponding to 16 or 19 grams), computer program  306  transmits a “no go” signal to dispensing system  200  indicating to dispensing system  200  to cease dispensing coating material “C” from dispensing head assembly  210 .  
         [0057]     With continued reference to  FIGS. 5 and 6 , as mentioned above, dispensing system  200  includes a purge cup  230  operatively associated therewith. In use, dispensing head assembly  210  rests in purge cup  230  when dispensing system  200  is idle. Preferably, purge cup  230  contains a quantity of solvent “S” therein. Suitable solvents “S” include and are not limited to at least one of a hydrocarbon solvent of from about 5 to about 10 carbon atoms, an alcohol, a hexane, a heptane, an isopropanol, and mixtures thereof.  
         [0058]     In operation, when dispensing system  200  is idle (i.e., not dispensing coating material “C” from dispensing head assembly  210 ), dispensing head assembly  210  rests in purge cup  230  such that the distal tip of dispensing head assembly  210  is submerged in solvent “S”. In so doing, solvent “S” prevents clogging of discharge nozzle  44  by minimizing the exposure of discharge nozzle  44  to ambient moisture and thus minimizing any silicon cross linking of coating material “C” that may take place. Accordingly, the free flow of coating material “C” from discharge nozzle  44  improves the consistent repetitive recreation of the material flow pattern (e.g., tornadic, swirling, etc.) exiting therefrom.  
         [0059]     With reference now to  FIGS. 5 and 6 , a preferred method of operation of dispensing system  200  is shown and described. In operation, a tray of needles  240 , traveling on a conveyor  250  or the like, in the direction of arrow “X”, enters a spray hood  260  (shown in phantom in  FIG. 5 ). Once tray of needles  240  is positioned at a desired and/or a predetermined location within spray hood  260 , dispensing system  300  is activated to spray a layer of coating material “C” onto tray of needles  240 .  
         [0060]     Dispensing system  200  raises dispensing head assembly  210 , originally maintained in purge cup  230 , out of purge cup  230  and maneuvered over tray of needles  240  in a predetermined pattern so as to completely cover needles  242  with coating material “C”. Preferably, dispensing head assembly  210  is maneuvered over the target site, i.e., tray of needles  240 , in a substantially rectilinear pattern (e.g., in the direction of arrows X′ and Y′).  
         [0061]     Reference can be made to U.S. Pat. No. 6,244,522, previously incorporated herein by reference, for a detailed discussion of the operation of dispensing system  200 . Preferably, coating material “C” is sprayed onto needles  242  until needles  242  are coated with a sufficient amount of coating material “C” or until the predetermined quantity of coating material (as determined by the reduction in weight of supply  220  as described above) has been dispensed and gravity feed system  300  transmits a “no go” signal to dispensing system  200 , at which time the dispensation of coating material “C” is terminated for tray of needles  240 .  
         [0062]     If the desired quantity of coating material “C” has been deposited onto needles  242 , the tray of needles  240  is further transported on conveyor  250  to the next stage of the manufacturing process. If, on the other hand, the desired quantity of coating material “C” has not been deposited on needles  242  of tray of needles  240 , the tray of needles  240  is re-cycled and/or otherwise discarded.  
         [0063]     Following, each application of coating material “C” to the tray of needles  240 , dispensing head assembly  210  is returned to purge cup  230  such that the distal end of dispensing head assembly  210  is submerged in solvent “S”. In this manner, solvent “S” prevents and/or inhibits clogging of orifices  80  and air jets  82  (see  FIGS. 4A and 4B ) of discharge nozzle  44  between successive spraying steps.  
         [0064]     As seen in  FIG. 7 , purge cup  230  can be provided with a cap or lid  232  including an aperture  234  formed therein. Preferably, aperture  234  is sized to allow reception and/or passage of barrel assembly  218  of dispensing head assembly  210  therein. Preferably, barrel assembly  218  is provided with a sealing member  236 , preferably in the form of an O-ring, disposed thereon. In this manner, when barrel assembly  218  is positioned in purge cup  230 , seal member  236  effectively seals the perimeter of aperture  234  thereby inhibiting the escape and/or evaporation of solvent “S” from within purge cup  230 .  
         [0065]     As further seen in  FIG. 7 , dispensing system  200  further includes a purge valve  270  in operative association with port  24 , preferably in fluid communication with conduit  222  interconnecting supply  220  of coating material “C” to port  24 . Purge valve  270  can be either manually or automatically operated. Desirably, purge valve  270  functions to drain dispensing system  200  of coating material “C” without opening dispensing head assembly  210 . Advantageously, by not opening dispensing head assembly  210 , to drain dispensing system  200  of coating material “C”, the flow rate of coating material “C”, between successive runs and/or uses of dispensing system  200  is maintained substantially constant and/or the same.  
         [0066]     The disclosure has been described with reference to preferred embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. The present disclosure is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.