Abstract:
The present invention concerns a spinning preparatory machine ( 1 ) with a drafting assembly ( 4 ) encompassing multiple roll pairs ( 5, 6, 7 ) by which a fiber band (FB′) can be drafted. The roll pairs ( 5, 6, 7 ) possess upper rolls ( 5   a   , 6   a   , 7   a ) and under rolls ( 5   b   , 6   b   , 7   b ). The roll pairs ( 5, 6, 7 ) are installed in a housing ( 15 ), wherein the roll pairs are protected from ambient atmospheric conditions about the preparatory machine ( 1 ) and from components thereof. A temperature controller ( 20 ) functions with the housing ( 15 ) to bring about internally a desired operational temperature, which is independent of temperature external to the housing ( 15 ).

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention concerns a spinning preparatory machine, especially a draft system or carding system, wherein the machine possesses a drafting section having multiple roll pairs in which a fiber band can be drafted. The roll pairs possess, in this arrangement, upper rolls and under rolls. Further, the invention concerns a housing for a draft system suitable for a spinning preparatory machine in accord with the invention.  
       BACKGROUND  
       [0002]     In the production and the work-up of fiber bands, especially for carding and drafting, the over stepping of certain specified temperatures, which may be harmful for given materials under treatment, must not occur in order to assure the maintenance of a constant process and uniform quality. Especially where polyester materials are involved, or sticky substances such as cotton, which may be coated with honeydew or certain chemical-fiber mixtures, drafting at a temperature exceeding 70° C. is scarcely possible. In a case of very high delivery speeds, greater than, for instance, 600 meters/minute, relatively high temperatures are produced, possibly by increased roll-action in the drawing rolls, which generally lead to process interruptions because of wind-ups. During the starting of the machine, on the other hand, the temperature at the rolls is often too low, so that, even so, in this case wind-ups can occur. Moreover, the air temperature/humidity conditions in spinning plants are subjected to great variations, due to lack of air conditioning, often large temperature and humidity differences can be found in the course of a working day. These conditions lead likewise to interruptions in operation during drafting.  
         [0003]     Usually, draft systems are provided with vacuuming apparatuses, which remove fibers from the draft system and therewith also the associated heat. However that may be, at high delivery rates, temperatures of up to 100° C. can be reached on the rolls, so that drafting cannot be carried out for all materials.  
         [0004]     DE 37 03 357 A1 proposes to provide the upper rolls of the draft system with a cooling system. The upper roll, in this case, can be cooled by an air stream, which is guided through the internals of the roll core. The temperatures at all upper rolls can be reduced by this means. However, it has proved itself as true, that the heat cannot be removed in satisfactory quantities, to maintain an appropriate temperature for the drafting of sticky materials.  
         [0005]     DE 1 921 208 teaches that for the operation of a textile process machine, especially a web machine, under artificially atmospheric conditioning, to encapsulate a hood over the machine, which isolates the entire equipment. For this climatic effect, the hood is connected to air conditioning equipment by inlet and outlet conduits. In order to assure accessibility to the machine, the hood can be lifted or lowered by means of a thrusting apparatus. By means of flaps in the hood itself, the machine can be serviced without the necessity of displacing the entire hood. A hood for encapsulating an entire machine is, however, very complex and cost-intensive. The service of the machine suffers by the opening and closing of the individual flaps. In order to establish the temperature of one, individual operational requirement, moreover, maintaining air conditioning of the entire room which contains the machine is not logical on an energy cost basis.  
       SUMMARY  
       [0006]     Thus a principal purpose of the present invention is to create a preparatory machine for spinning, which, in a simple manner, enables a drafting of all materials independently of the surrounding climatic conditions, even at high rates of delivery speeds. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.  
         [0007]     The objects are achieved with a preparatory machine for spinning and a housing with features in accord with independent claims.  
         [0008]     In the drafting assembly of a preparatory machine for spinning, in accord with the invention, a band of fiber can be drafted. The invention concerns itself in regard to drafting or carding with an assigned draft system. However, the invention is applicable in other preparatory machines for spinning that possess a draft system, for instance, a combing machine. The draft system possesses several roll pairs, which consist of upper and lower rolls. In accord with the invention, the roll pairs are arranged in a housing, wherein, for the lowering of the temperature in the interior of the housing, at least one temperature controller is assigned, whereby the enclosed draft system is isolated from the driving units of the machine. The operational temperature in the drafting assembly, in particular on the rolls thereof, by this means and with simple operation, can be held at an appropriate value, without engaging the service personnel of the machine.  
         [0009]     The sought after temperature control of only a relatively small zone of the operation can, in this way, be brought about with small energy and cost expenditure. Any supplemental warming of the drafting machine by encompassing, heat generating components, such as, for example, the driving motors of the draft system, is prevented by the described housing. The housing serves, in this way, as a temperature shield against heat producing sources, which may be found in those parts of the preparatory machine for spinning which lie outside of the housing.  
         [0010]     It is also of advantage if the housing separates the roll pairs from the atmospheric conditions of the working space of the machine. The housing can be made of plastic or built of metal. For the separation, it is possible that an insulation layer can be applied to the housing surface. Such insulation would also prevent loss of cooling potential into the ambient space, as well as block the inward migration of heat from the surroundings.  
         [0011]     Likewise, it is also possible to furnish the housing walls with a reflecting coating. The distancing effected by the pair of housing walls in blocking out the ambient room conditions enables, in a particularly favorable manner from an energy standpoint, the maintenance of an optimal operational temperature. By this means, control over the source of temperature regulation is considerably simplified.  
         [0012]     In accord with an advantageous embodiment of the invention, provision has been made that the at least one temperature controller is designed to hold the internal temperature at a constant approximation to, at best, 40° C. A temperature in a draft system of 40° C. has proved itself to be optimal for a drafting operation. Substantially higher temperatures (e.g. 60° C. to 70° C.), in the case of chemical fibers, generally lead to changes in the fiber structure, including incipient melting. In the case of cotton fibers, problems with honeydew accompany increasing temperatures. Temperatures of 25° C. and lower lead, however, likewise to problems with winding and balling. By means of a continuously constant temperature maintenance, with the aid of a source of temperature control, it is possible that upon the start-up of the machine the draft system can be very simply brought to an optimal, operational temperature for the drafting. An integral temperature controller is thus of use also for the heating up of the machine during the start-up phase. In this way, a uniform quality of the received fiber band can be achieved, independently of the operational condition of the preparatory machine for spinning. The build-up of windings and balling, likewise can be considerably avoided.  
         [0013]     Another advantageous embodiment of the invention provides that at least one temperature controller is designed to allow the generation of different, adjustable temperatures. The temperature, in this way and in a simple manner, can be made to fit the operational conditions of the machine. A warm-up of the draft system to the operational temperature is made very quickly in this manner. Likewise, the optimal operational temperature and climatic conditioning can be quickly adjusted for each fiber in accord with its material. In a particularly advantageous embodiment of the invention, the at least one temperature controller can be installed both as a source of cooling as well as heating. As a source of temperature control, it is possible that Peltier elements can serve, which, in accord with polarity, produce a heating and a cooling side.  
         [0014]     Likewise, even a heating unit can be additionally provided with a cooling source, in order to bring the draft system up to operational temperature upon start-up. Installed elements, which serve principally as a sole source of cooling, are also available.  
         [0015]     Another advantageous embodiment of the invention provides that the at least one temperature controller is a main air conditioning unit capable of the servicing of multiple machines. The cooling of a draft system of multiple machines is likewise similar to a warm-up of the starting phase or is particularly of advantage in an economical manner after operational interruptions.  
         [0016]     A further advantageous embodiment of the invention provides that the at least one temperature controller be decentralized, or at least placed on (external to) the preparatory machine for spinning. In this way, it becomes possible to reach an individual operational temperature in draft system of separate machines. Energy consumption and cooling load can thus be made to fit the individual machine, as well as be in compliance with the material to be worked.  
         [0017]     In yet another advantageous embodiment of the invention, an air cooling source is placed on the preparatory machine for spinning to serve as the temperature controller. The cold air therefrom can advantageously be accurately directed against the heat producing components, namely the upper rolls, whereby a particularly fortunate cooling is achieved. Since the working of rolls in the elastic circumferential covers of the upper rolls for the draft system leads to an especially high development of heat within these covers, it is advantageous to have the direction of the cooling air centered directly on the upper rolls for a particularly efficient cooling. If, additionally, the entire interior space of the housing is subjected to the flow of cooling air, then additionally, a sufficient removal of heat from the total operational zone is achieved.  
         [0018]     In an advantageous manner, a feed opening for the inlet of the temperature adjusted media from the cooling system is provided through an opening in the housing and another opening is made for the exit of the used cooling medium from the housing. In this way, an operationally favorable through-put of tempered air for the temperature control of the draft system can be attained.  
         [0019]     In another advantageous embodiment of the invention, the at least one temperature controller is located within the housing, which makes possible an especially compact, simple and well designed arrangement of the invention.  
         [0020]     In a corresponding embodiment, it is possible that at least a part of the housing wall—that is to say, in addition to other means for the cooling of the interior space within the housing—can be cooled, in order to reduce the temperature within the housing.  
         [0021]     It is likewise of advantage if the at least one temperature controller is in connection with the interior of a hollow pressure bar, whereby the cooling medium produced by the cooling source can exit into the hollow space and from there, be released through at least one opening from the hollow pressure bar. The pressure bar, which serves for the guidance of so-called floating fibers between two drafting roller pairs, also allows a preset temperature control of the housing, especially the two drafting rolls between which it is located. It is possible that more than one such connecting conduit can be placed in the housing, so that the cooling medium can be accurately directed onto more than one roll. A hollow pressure bar, appropriate for the inlet of a cooling medium, in accord with the invention, is at least made partially hollow and possesses an outlet opening for the cooling medium. It is also possible that a plurality of openings for the cooling medium can be furnished in order that the infeed of cooling air is distributed in a uniform manner. A specifically directed heating of the rolls up to their operation temperature at the start of operations is also possible.  
         [0022]     For a predetermined feed of cooling medium, it is possible that one or more apparatuses for inlet of cooling medium in the housing can be advantageously placed between, respectively, two upper and lower rollers of two neighboring roll pairs, which, as in the previously described pressure bar, are connected to the temperature controller. The cooling medium produced by the one only temperature controller releases itself by one or more outlet openings of the respective, advantageously hollow feeding apparatus. Advantageously, the cooling medium is directed to flow over the total, or nearly total breadth of a roll, which is to say, the width of the fiber band which lies on the corresponding circumferential roll surface.  
         [0023]     A particular advantage of the invention provides that the cooled air from the at least only one temperature controller, that is to say, cold air, is directed to flow counter current to the fiber-drawing direction in the housing. Since the temperature development at the downstream rolls is higher than at the upstream rolls, a through-flow in the direction of the drop in temperature within the housing creates an especially efficient cooling.  
         [0024]     Another advantageous embodiment of the invention provides that the cooling medium from the at least one temperature controller, in particular, cooling air, can be conducted through the housing in the direction of the draw of fiber. Since, in the main drawing field, a greater flight of fiber particulate arises than in the upstream predrawing field, suction devices are frequently installed in known machines in the drafting/drawing direction following the initial rolls. In the case of a through-flow of the housing in the drawing direction, in this case, the use of a suction system can be advantageously supported.  
         [0025]     The above described advantage, namely that the cold air flowing through the housing—in general, the cooling medium—removes fibers and/or dirt from the area of the drawing field, is also achievable by a suction, which induces flow counter to the direction of drawing. Instead of, or in addition to, a source of vacuum, which is responsible for removal by suction, by means of a corresponding, fitting geometry of the housing, also a compressed air source can find use, which, advantageously, is bound to the temperature controller in order that the air produced by the center can transport fibers and/or dirt out of the housing.  
         [0026]     In a development of the invention, the proposal is made that the at least one temperature controller be attached to a an electronic control apparatus. The load for the cooling can then be continually adjusted to be dependent upon the ambient conditions and on the characteristics of the material to be treated. At the same time, at the start of the operation, the machine can be brought up to the operational temperature quickly and simply since, as required at the start, heat or warm air can be immediately introduced.  
         [0027]     Another particularly advantageous development of the invention provides that the temperature controller itself can be regulated. That is to say, the maintenance of a preset temperature level and an optimal fitting to various operational conditions may be automatically programmed. Advantageously, for this purpose, at least a sensor can be installed for the determination of the temperature and/or to include additional parameters in or on the housing. Thus, the operational temperatures in various areas of the draft system can be determined and accurately set at a predetermined level.  
         [0028]     A housing, in accord with the invention, for a draft system of a preparatory machine for spinning is so constructed that roll pairs of the draft system, which consist of upper and under rolls, are encapsulated by the housing. In enabling this, the housing isolates the roll pairs from the ambient room climate around the machine and protects them from further components of the machine itself. At least one temperature controller is ascribable to the housing, so that in the housing a temperature may be generated, which is not dependent in any significant way on the surrounding room temperature whereby an independent temperature may be developed. By means of the positioning of the roll pairs in the housing, it becomes possible to bring temperature control only to an active working zone of the draft system and do this in an economical manner.  
         [0029]     Advantageously, in the housing are placed openings for the input of a cooling medium generated by the temperature controller and for the outlet thereof. Further respective openings for the inlet and outlet of a fiber band are provided. With this situation, a circulation of the cooling medium is made possible so that the developed heat can be optimally led away.  
         [0030]     In a particularly advantageous embodiment of the invention, the openings for the inlet and outlet of the cooling medium are so arranged that the through-flow in the housing can be in the upstream direction of the drawing field, whereby an optimal coaction with an eventually additional, attached apparatus for the removal of fiber material becomes possible. Suction based or blow through devices of this type transport fibers and dirt, normally in the upstream direction out of the drawing field. A through-flow in the housing in the downstream direction of the drawing field can, however, be of advantage since the cooling medium first reaches those components, which show the greater development of heat.  
         [0031]     A further advantageous embodiment of the invention provides that the housing be made somewhat transparent in order that a visual control of the drafting procedure is possible. Likewise, for the visual control, a transparent window or an observation flap can be placed on the housing.  
         [0032]     Further, it is of advantage if the housing is constructed of at least two parts, so that for the purposes of maintenance or upkeep, opening is easily carried out. Advantageously, the housing would exhibit an upper part and an under part, whereby the upper part is made to be relatively movable away from the under part. If the upper part of the housing is constructed to be pivotally parted, relative to the under part, then the manipulation is relatively simple. It is also of advantage if the upper part of the housing is connected to a structural arm on which the upper rolls of the draft system are placed. The opening and the closing of housing, in this case, is directly connected with the lifting/lowering of the structural arm so that additional work steps in regard to the machine servicing and maintenance are not necessary. The constructive design of such a housing is made easier by this measure.  
         [0033]     Another likewise advantageous development of the invention provides that the upper part of the housing is bound to a topping, which extends itself over the entire draft system. The opening of the housing is done, in this case, directly with the lifting of the topping. Alternatively, the upper part of the housing is itself designed as a topping.  
         [0034]     A further, advantageous embodiment of the invention characterizes itself in that the housing possesses yet another opening, which acts with an external pressure or suction source. In this case, it is possible to reliably remove and transport away fiber material and dirt from the drawing section.  
         [0035]     Further advantages relative to the invention are described in the following, based on illustrated embodiments serving as examples. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0036]      FIG. 1 a  schematic presentation in profile view of a preparatory machine for spinning in accord with the invention,  
         [0037]      FIG. 2 a  schematic presentation of a housing in accord with the invention for a draft system with a cooling air source as temperature controller,  
         [0038]      FIG. 3 a  detail presentation of a draft system with a temperature controller, which connects with a hollow pressure bar,  
         [0039]      FIG. 4 a  further embodiment example of a housing in accord with the invention in a schematic presentation,  
         [0040]      FIG. 5  an additional embodiment example of a housing in accord with the invention in a schematic presentation,  
         [0041]      FIG. 6 a  schematic presentation of a housing, in accord with the invention, showing a two-part, pivotal design, and  
         [0042]      FIG. 7 a  schematic presentation of a cooling air source for the cooling of a housing in accord with the invention. 
     
    
     DESCRIPTION  
       [0043]     Reference is now made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment may be used with another embodiment to yield still a further embodiment.  
         [0044]     In  FIG. 1  is shown, in schematic profile view, a draft system as an example of a preparatory machine for spinning  1 . In accord with this example, one or more fiber bands FB are presented next to one another on the operating draft. Principally, these bands, for the sake of clarity, are shown in plan view. At the start of the draft system is placed a compaction apparatus  19  for the fiber bands FB. After running through a mechanical scanning device  2 ,  3 , the now compacted fiber band FB′, which is comprised of the original several bands FB, is guided into a draft system  4 , which constitutes the core piece of the drafting. The draft system  4  possesses, as a rule, three drawing organs, these being normally roll pairs, between which the force of the drawing is generated. These three roll pairs are the entry roll pair  5   a ,  5   b , the middle roll pair  6   a ,  6   b  and the output (or delivery) roll pair  7   a ,  7   b . These turn in this given series, each providing an increase in rotational speed. By means of these successive roll pairs, the fiber band FB′ is drawn, in accord with the corresponding circumferential speeds. The entry roll pair  5   a ,  5   b  and the middle roll pair  6   a ,  6   b  form the so-called predrawing field VF, the middle roll pair  6   a ,  6   b  and the delivery roll pair  7   a ,  7   b  establish the so-called main drawing field HF. In the main drawing field HF, additionally a pressure bar  8  is located, which causes the fiber band FB′ to divert its direction of travel to achieve a better guidance of the fibers. This action applies to the fibers (also known as floating fibers) which are not clamped between the roll pairs  6   a ,  6   b  and  7   a ,  7   b . The drawn fiber band FB′ is consolidated with the aid of a turn-around, upper roll  9 , a band forming apparatus  10  and by means of a calender roll pair  11 ,  12 . Finally, an adjustable band conducting tube  13  stores the band FB′ in a can  14 .  
         [0045]     The roll pairs  5 ,  6  and  7  of the draft system are to be found in a housing  15 , which isolates them from both the ambient room climatic conditions as well as the additional components of the machine. In the present example, only the drawing rolls are shown within the housing, however, it is still possible to locate the calender rolls  11 ,  12  in the housing, as may be seen in  FIG. 6 . The fiber band FB′ runs through an opening  22  into the housing  15  and correspondingly exits the housing through another opening, namely  23 .  
         [0046]     The housing  15  possesses additional openings  16 ,  17  for the inlet and outlet of the cooling medium K, which openings are, in the present design, respectively bound by lines  18  to a temperature controller  20 , which produces the cooling medium K. In order to achieve a particularly uniform temperature control within the housing  15 , the inlet and the outlet of the cooling medium K can also be directed over two or more openings, as shown in  FIG. 4 . In a not shown alternative embodiment, principally the inlet opening  16  is directly connected to the temperature controller  20 , while the outlet opening  17  yields the warmed cooling medium into the surrounding ambient room conditions. In the present example, the temperature controller  20  is not located for service to multiple units, but is dedicated to the given machine  1 . A general temperature controller  20  for common supply to multiple machines  1  is likewise a possibility. By means of the temperature controller  20  as shown, it is further possible that, in the draft system  4 , appropriate temperatures may be specially adjusted for higher delivery speeds (for example, above 500 m/min for polyester or sticky cotton).  
         [0047]     By means of the temperature controller  20  it is possible that in certain operational conditions, for instance upon the start-up of the machine  1 , i.e., of the draft system  4 , the contained air within the housing  15  can be heated. The temperature controller  20 , in such a case, may be furnished with an auxiliary source of heat or possess a cooling means which can also be converted to heat production. If the temperature controller  20  generally delivers a constant temperature, it is also possible that thereby the interior of the housing  15  can be heated therewith, insofar as the temperature within the housing  15  lies below this temperature.  
         [0048]     A further variant of the invention provides that by employing the cooling medium K issuing from the housing  15 , the drive motors (not shown here), of the machine  1  may be cooled. The line  18  for the outlet of the cooling medium K is, in this case, not connected to the temperature controller  20 , but rather an additional line  40  leads to the cooling drive units. Especially in the case of higher surrounding temperatures of about 40° C., which are not to be found in air conditioned spinning plants or in lands of high temperatures, the outlet cooling medium can still be relied upon for a satisfactory cooling of the drive units. Additionally, the cooling medium K, which is not yet exposed to heat, that is, the cold air, i.e. unused cooling medium K, can be branched off over an additional line  41  from the feed line  18  and likewise used for the cooling of the said driving units.  
         [0049]     By means of the positioning of the roll pairs  5 ,  6 ,  7  in the housing  15 , it becomes necessary to cool only a relatively smaller zone, so that an appropriate operational temperature can be achieved economically and with a small consumption of energy. Thermal influences of neighboring components and issuing heat from the surroundings are blocked by the housing  15 . The drafting of optional material of fiber bands FB′ is, in this individual manner, entirely possible even at high delivery rates. Operational process interruptions by swinging climatic conditions in the surroundings of the preparatory machine for spinning  1  are likewise greatly repressed, so that a machine of this type, in comparison with other known machines, assures increased production loads. If the drafting of colored material is to be expected, then it is possible that by means of the cooling, alterations of temperature sensitive coloring pigments can be prevented.  
         [0050]     The temperature controller  20  incorporates a control apparatus  21  so that the operational temperature in the draft system  4  can be regulated within defined parameters. The loading of the cooling, in such a situation, can be dependent upon the temperatures at the upper rolls  5   a  (or  6   a ) and  7   a , which are provided with sensors  25  for this purpose. Additionally, the humidity in the drafting zone can be adjusted to a specified level. The temperature controller  20  can, however, be interconnected with a control apparatus, which enables a simple matching to different operational conditions. If the temperature controller  20  is formed from an air conditioning unit, this can be used in a very simple way, in order that the draft system can be warmed to a specified temperature level before start-up of operation. In this way, in any operational state of the machine, optimal conditions can be brought about for drafting.  
         [0051]     A particular effective cooling of the roll pairs  5 ,  6 ,  7  can be reached if the cooling medium K of the temperature controller  20  is directed directly upon the upper rolls  5   a ,  6   a ,  7   a  of the draft system  4 . This is shown in  FIG. 2 . In this arrangement, a cold air source is placed in the housing  15 , which produces coolant flow through a plurality of diversion ducts to the upper rolls  5   a ,  6   a ,  7   a . In accord with the arrangement of the cold air source, it is possible that individual areas can be targeted for cooling, whereby even an arrangement of several cold air sources within the housing  15  becomes possible. Likewise, the cold air source can be so positioned that the roll pairs  5 ,  6 ,  7  can be subjected to flow from only one duct of cold air. A cold air source of this nature can be placed for defined cooling of individual components and be installed auxiliary to a central or a decentralized temperature controller  20 .  
         [0052]     In the present embodiment, the openings  22 ,  23  to accommodate the fiber material are sealed off by rubber collars or rounded off stainless steel edges  27  to block out incursion of outside interfering influences. For the opening of the housing  15 , for instance for maintenance purposes, the housing is designed to be of two parts, with a removable upper part  15   a  as well as an under part  15   b  integrated with the machine  1 .  
         [0053]     At the opening  17  in the presented embodiment, an outlet  18  is connected. This can be, for instance, connected to a suction source, in order that the cold air, which has been warmed within the housing can be removed. Alternative to this (but not shown), the opening  17  can lead directly to the surrounding free air, that is, no outlet line is provided. By means of the opening  16 , it is possible for the source of cold air to feed in air which has not yet been cooled. Instead of the cold air source which is depicted here, another temperature controller  20  can be provided in or on the housing  15 , whereby the opening  16  would be connected to the temperature controller  20 . The opening  17  can, as explained above, be connected to a suction source, discharge directly to the room surroundings, or be run back by an outlet line  18  to the temperature controller  20  as is demonstrated in  FIG. 1 . Also, the supplied air source can, for instance, serve for warming the housing  15  at the beginning of the process.  
         [0054]      FIG. 3  shows a detail presentation of the roll pairs  5 ,  6 ,  7  of a draft system  4 . The roll pairs  5 ,  6 ,  7  are also mounted within the housing  15  (housing not shown). The temperature controller  20  for the cooling of the rolls  5 ,  6 ,  7  and the housing  15 , in this case, is so connected to the interior of an at least partially hollow pressure bar  8 , that the cooling medium K can be introduced through at least one outlet opening into a higher thermally-loaded zone of the main draw field of the main drawing field. In order to achieve a uniform cooling of the roll pairs  5 ,  6 ,  7 , it is possible that a plurality of pressure bars  8  can be put to use at or between each two of the roll pairs  5 ,  6 ,  7 . This is indicated in  FIG. 3  by dotted lines. The inlet apparatuses  24  can, for example, be of hollow, rigid construction with one or more outlet openings  29 . By means of these openings  29 , the cooling medium K can be targeted onto the to-be-cooled rolls so that an effective cooling results. The outlet openings  29  of an inlet apparatus  24  can be aimed directly upon the upstream and downstream rolls. The output openings  29  for the one and the other rolls can thus be angularly located, relative to one another (seen by cross-sectional observation.)  
         [0055]     It is of particular advantage if the inlet apparatuses  24  are placed in pairs between the rolls, so that the upper rolls  5   a ,  6   a ,  7   a  and the under rolls  5   b ,  6   b ,  7   b  are subjected to cooling medium K at each inlet apparatus. The inlet apparatuses  24  possess, in accord with an advantageous embodiment contour, no touching contact with the fiber band FB′, as may be seen in  FIG. 3 .  
         [0056]     Above the draft system is a conventional suction collection line  30 , which, with the aid of a remotely attached suction source  31  (this source being only schematically indicated) transports fibers, dirt and heat away from the draft system zone. Along with the cooling, this arrangement allows a satisfactory removal of fiber material and dirt out of the principal drawing field HF, since contamination and foreign particulate is eliminated by the cooling medium K feeding into the suction collection line  30 .  
         [0057]      FIG. 4  shows a further embodiment of a housing  15 . The openings  16 ,  17  for the inlet and outlet of the cooling medium K are so ordered in this case that the housing  15  experiences a through-flow from upstream, i.e., the same as the drawing direction. In order that an especially uniform through-flow and cooling of the draft system  4  can be reached, the housing  15  is provided with two openings, namely  16 ,  17 , for the inlet and the outlet of the cooling medium K. The cooling medium K passes through a least one temperature controller  20  by means of the openings  16  into the said housing  15 . By means of this design, two parallel flows are formed, so that the upper rolls  5   a ,  6   a ,  7   a  and the under rolls  5   b ,  6   b ,  7   b  are evenly cooled. The air flow, that is the flow of cooling means, reliably removes the accumulated heat in the draw fields VF, HF. Moreover, fibers and contamination from the draw fields VF, HF are removed by the flow of cooling medium so that no additional suction or blower apparatuses need be used. The flowing cooling medium K, as well as the therein carried fiber and contamination particulates, find exit through openings  17 , so being freed of the housing  15 .  
         [0058]     A housing  15  in a further alternative embodiment in accord with the invention is of two parts, as presented in  FIG. 5 , wherein the interior of the housing  15  is subjected to the through-flow of a cooling medium K from upstream. Additionally, above the rolls  5 ,  6 ,  7  is installed a suction collection line  30  with a remote suction source  31  for the removal of fibers and contamination out of the drawing fields VF HF. The housing  15  possesses in this instance, an additional opening  40 . Instead of the suction removal line  30 , it is possible to substitute a direct blowing source.  
         [0059]      FIG. 6  demonstrates an embodiment of the two-part housing  15  wherein the top part  15   a , in which the inlet and the outlet openings  16 ,  17  are provided, is pivotal (see arrow “f 1 ”). The top part  15   a  is connected to a structural arm  32  so that by the pivoting upward of the structural arm  32  about an axis  35 , the interior of the housing  15  is made available. The top part  15   a  can be solidly affixed to the structural arm  32 , or it can be releasably fastened thereto. The bottom piece  15   b  is integral with the preparatory machine for spinning  1 . In the present example, even the calendar rolls  11 ,  12 , where substantial amounts of heat are generated, are placed within the housing  15 . In order to assure access to the draft system  4  from the top side as well as proximal to the structural arm  32 , the housing  15  has been furnished with a pivotal flap  33  rotating about an axis  34  (for this see  FIG. 6 , designation f 2 ). This flap  33  may be of a transparent material to enable visual monitoring of the drafting process when the housing  15  is in the closed position. The reference number  36  represents a plastic, spacing gasket, which serves as a sealing device to maintain a high degree of tightness for the housing  15 .  
         [0060]      FIG. 7  shows a schematic presentation of the at least one temperature controller  20  for the temperature adjustment of an invented housing  15 . The temperature controller  20  is supplied with compressed air by a connection piece  37 . By an irreversible, adiabatic expansion in the interior of the said temperature controller  20 , the cold air K is generated, which can flow out of the temperature controller  20  through outlet fitting  38 . With incoming, raw air at a constant pressure and temperature, it is possible that resulting cold air K itself can also be produced at a reliable, constant temperature. By means of an adjusting valve  39  the temperature as well as the rate of generated flow of the cold air K can be regulated. With such a temperature controller  20 , it is possible that operational temperature in the interior of the housing  15  can be maintained in a simple space saving, economical manner. The temperature controller  20 , in this case, can be located in or on the housing  15 . Likewise, arrangements of a plurality of temperature controllers  20  is possible.  
         [0061]     This invention is not limited to the here presented embodiment examples. There are many more alternatives of the invention and combinations acceptable within the framework of the invention.