Title of Invention

A DRAW FRAME

Abstract

The present invention relates to a draw frame having a drive device located in a drive space which can be covered by means of a movable cover resting by its edge region upon a stationary part of the draw frame, wherein the drive space accommodates at least one fan having at least one intake and one outlet, the intake of the fan being connected, with the interposition of a filter, to an area outside of the drive space, and the outlet of the fan ending in the drive space.

Full Text

The present invention relates to a draw frame having a drive device arranged in a drive space which can be covered by means of a movable cover resting by its edge region upon a stationary part of the draw frame. In draw frames, the individual drives, such as main drive, overdrives, e.g. for the can change, drafting-arrangement drive, revolving-plate drive etc., are covered with the aid of at least one hinged cover. Such a cover is usually made of sheet metal so that on the one hand it is easy to handle without too much effort and on the other hand it can be produced inexpensively. Since the drives take up a relatively large amount of space, the cover too must have correspondingly large dimensions in order to allow accessibiUty to all the individual drive assembHes. Such a large cover is thus pUable to a certain degree, even if measures are taken to counter this by reinforcing its edge regions, and consequently does not rest in a completely sealing manner upon its vinderlying surface, which is formed by a stationary part of the draw fi-ame. This always results in openings and gaps through which air can penetrate into the said drive space accommodating the drive device(s). Since the space surrounding the draw frame cannot be kept completely free from fibres and other fly components which are floating around, in the known designs there is no way of preventing, for a justifiable sealing outiay, such undesired components from getting into the drive space, collecting on the parts, some of which revolve at high speed, and thus possibly resulting in damage. An object of the present invention therefore is to provide a draw frame having a device which can be manufactured for littie outiay and effectively prevaits penetration of fibres into the drive space and thereby contributes to a long service Ufe of the drive assembUes. The invention provides a draw frame as claimed in Claim 1. The fan is used to generate in the drive space a positive pressure which causes air to escape, over the entire edge region of the cover, into the atmosphere surroimding the drive space. There are thus no uncontrolled, uncleaned air flows penetrating into the drive space and there is thus no undesired penetration of fibres and other fly components either. The drives are thus not impaired in their functioning and/or durability due to deposits. The invention enables the use of existing equipment in a draw fi-ame. By virtue of the connection to a fan, the air currents generated by the equipment can be appropriately and effectively used. Moreover, the invention makes it unnecessary to carry out any changes in the construction and design of a draw frame. Retrofitting of existing draw frames is also possible for little outlay. It is particularly favourable if fans akeady present in the drive space, for example for the main drive, are used for the invention. This results in a considerable cost reduction. It is advantageous furthermore if the intake of the fan is arranged in the upper and/or lower region of the drive space. Upon orientation of the fan intake towards the top, i.e. in the upper region of the drive space, less dirt is sucked in, since far fewer dust particles are present there. If the fan intake is constructed towards the bottom, then by using a large-area intake area a low flow rate can be employed, so that less dirt is sucked in this case as well. This type of large-area intake is particularly appropriate when the drive space is arranged on abase. In principle, the arrangement and orientation of the fan in the drive space may be freely chosen, but a particularly expedient solution in terms of the air economy can be achieved by a design of the subject-matter of the invention according to Claim 3 and possibly Claim 4. The air-guiding device enables air to be guided to specific locations in order to perform cleaning or dust removal precisely at these locations. For, owing to the design of certain constructional units, it is not possible to prevent dust from being deposited at some locations. These deposits are now avoided by means of the invention. To facilitate maintenance, a development of the device of the invention in accordance with Claim 5 is advantageous, smce the fan does not thereby impair the accessibility of the assemblies arranged in the drive space when the cover is open. In this case, it is expedient to construct the device as per Claim 6 to reduce the effort required by the maintenance person. Simple cleaning of the filter can be achieved by a design of the device of the present invention according to Claim 7. Since a large part of the drives arranged in the drive space do not need to run during catain operations on the draw fi^ame, e.g. during the exchange of a can filled by the draw fi'ame for an empty can, it is expedient if the device of the invention is developed in accordance with Claim 8, in which case, by advantageous construction of the control device according to Claim 9, the time during which the fan rotates in the direction opposite to the normal running direction during operation can be reduced to the amount which is unavoidably necessary. By the advantageous arrangement of the filter in accordance with Claim 10, the accessibility of the same is considerably improved. In the simplest case, it is sufficient if the fleece which forms on the filter from these fly components in the course of time is merely blown off and falls onto the floor, but it is expedient if a design according to Claim 11 is provided for the disposal. In order not to hinder the attendant during the maintenance of the draw frame, a design of the device of the invention according to Claim 12 may advantageously be provided. In this case, an advantageous development of the subject-matter of the invention according to Claims 13 to 15 is recommended. A connection of the disposal device in accordance with Claim 15 and possibly 16 is preferably provided here. For the purposes of the present invention, the term "fan" also embraces a multipUcity of the same when suitably arranged in the drive space. The same apphes to the "cover", this term also being intended to embrace doors, flaps etc. Similarly, instead of a single drive space a multipUcity of q)propriately designed drive spaces may also be provided, should this be expedient for space reasons. The subject-matter of the invention is simple in terms of construction and nevertheless counteracts the penetration of fibres and other fly components into the drive space with a high degree of reliability. The subject-matter of the invention thereby increases the operational reliability of the drive assemblies and extends their service life using simple means. The air flow generated in the drive space additionally serves for cooling the drive devices and assemblies. Accordingly, the present invention provides a draw frame having a drive device located in a drive space which can be covered by means of a movable cover resting by its edge region upon a stationary part of the draw frame, wherein the drive space accommodates at least one fan having at least one intake and one outlet, the intake of the fan being connected, with the interposition of a filter, to an area outside of the drive space, and the outlet of the fan ending in the drive space. Further details and features of the invention are explained with the aid of the drawings, in which: Fig. 1 shows a perspective view of a draw frame designed in accordance with the invention; Fig. 2 shows a diagrammatic section through the drive space of a draw frame in the design according to the invention; Fig. 3 shows a perspective representation of the control diagram for a draw frame designed in accordance with the invention; and Fig. 4 shows a perspective representation of a detail of the subject-matter of the invention. In order to gain a better understanding of the essence of the invention, a draw frame 1 is first explained in broad terms with the aid of Fig. 1. The lower part 10 of this draw frame 1 is stationary and forms a machine frame which is designed in the customary fashion and has doors 11 and the like. On the left-hand side of the figure, several cans 12 can be seen, from which the slivers 13 to be drafted are fed to the draw frame 1. The slivers 13 are united (doubled) in a sliver-guiding channel 15 and drawn, and deposited in a can 14. Many different drives, which will be explained in more detail later in connection with Fig. 2 and which are arranged in the stationary part 10 of the draw frame 1, are required for the various activities on the draw frame 1, such as the drawing of the slivers 13, monitoring of the sUver which is being formed by drawing the sUvers 13 and is to be deposited in the can 14, for the controlled depositing of this drawn sUver in the can 14, for the exchange of a filled can 14 for another can 140 previously in the waiting position (can change) etc. Most of these drives are situated together in a single space (drive space 3) which is covered by covers 2,2a and 2b. Because of the shver-guiding channel 15, it is necessary to provide a pluraUty of covers 2,2a, 2b; their number depends on the design of the draw frame 1 and may thus vary accordingly from one type of draw frame to another. The covers 2,2a and 2b are each pivotable about an axis, not visible in the figure, so that the drive space 3 (see Fig. 2) accommodating the aforementioned drives is accessible for maintenance purposes. Further drives or drive elements may be housed in one or more additional drive spaces (not illustrated here) which can be made accessible, for example, by opening a door 11 (Fig. 1). This appUes, for example, to the aforementioned device for changing the cans 14,140 (can-changing device 35). For the sake of clarity, the drives etc. are merely illustrated diagrammatically as rectangles in Fig. 2, but it goes without saying that these drives have, in the customary fashion, gearings with corresponding numbers of the various spar wheels and other gearwheels, chains, drive belts etc. and as a rule do not have any further encapsulation or the like inside the drive space 3. According to the exemplary embodiment shown in Fig. 2, this drive space 3 accommodates a main drive motor 30, the drive shaft 300 of which is connected to a gearing 31. This gearing 31 is used to drive, in the example shown by means of overdrives which may be designed in any desired manner per se, a drafting-arrangement drive 32, a drive device 33 for the sUver scanning and also a revolving-plate drive 34 which sets a revolving plate 340, arranged above the can 14 to be filled, in rotation during the filling operation, in order to distribute the sliver, which is to be deposited, uniformly in the can 14. Further drives, e.g. for the aforementioned can-changing device 35 (see Fig. 3), may be derived from the gearing 31, even if they are situated in another drive space (or in a plurality thereof) separated from the drive space 3. The aforementioned drives (30,31,32, 33,34) contain, as mentioned, a multiphcity of rotating and revolving parts which are not further encapsulated inside the drive space 3, but are arranged open in the drive space 3 because of the accessibility and heat removal required. A fan 4 is movably connected to the cover 2. In the exemplary embodiment shown, the fan 4 is flanged by its intake side directly to the side wall 20 of the cover 2. To prevent any fibres and other Ught fly components flying around in the air surrounding the draw frame 1 from getting into the drive space 3 as a result of the fan 4, a filter 5, through which the air fed to the fan 4 is sucked in, is arranged in the side wall 20 of the cover 2. Only clean, filtered air, which is thus free from fibres, fibre fragments and other fly components, thereby reaches the fan 4 and accordingly only such filtered air gets into the interior of the drive space 3 as well. Before discussing the control system and other details of the device construction, its mode of ftinctioning will first be explained. During normal working operation of the draw frame 1, in which the main drive motor 30 is running and via the gearing 31 and the drafting-arrangement drive 32 drives the drafting arrangement (not shown) for drawing the slivers 13, vwth the aid of the drive device 33 drives the sliver scanning (Ukewise not shown) and with the aid of the revolving-plate drive 34 drives the revolving plate 340, the fan 4 is driven, and clean air is sucked in by its intake side trough the filter 5 and blown on its air outlet side into the drive space 3. This air generates in the drive space 3 a positive pressure which results in the air leaving the drive space 3 through all the openings and gaps 21 in an effort to leave, to create, a pressure equalization between the drive space 3 and the space surrounding the latter. At these locations where the air can escape from the drive space 3 (see arrows L), i.e. at the edge regions of the covers 2,2a and 2b by which they rest on the stationary part 10 of the draw frame 1, tha-e is no need to provide any seals and the like, since this outflow of air is even desirable in order to obtain the effect being striven for. This is because the air flowmg out through the openings and gaps 21 prevents air, i.e. even uncleaned air, at any location except through the fan 4, from getting into the drive space 3 and thus possibly resulting in soiling and eventually even to damage of driven parts of the drives and gearings. It has been found that the effect being striven for is ensured when there is a pressure of about 300 to 400 pascals in the drive space 3. As is evident from Fig. 1, the drive space 3 has an angled shape since it partly encompasses the shver-guiding channel 15. For this reason, it may be difficult to maintain a constantly sufficient positive pressure in the entire peripheral region of the covers 2,2a and 2b, i.e. over the entire length of the openings and gq)s 21 between the covers 2,2a and 2b on the one hand and the stationary part 10 of the draw frame 1 on the other hand, to rule out penetration of fibres and other fly components with certainty at all points. This can be remedied m various ways. For example, it is possible to provide a stronger fan 4 which circulates a greater quantity of air and thus ensures that the aim being striven for is achieved. However, this necessitates a higher expenditure of energy. Another possibility is to arrange the fan 4 at a central location inside the drive space 3 and orient it accordingly, so that the air leaving it is distributed as uniformly as possible in the drive space 3 and thus also blown outwards in relation to the drive space 3 substantially with the same intensity over the entire region of the gaps 21 present between covers 2,2a and 2b on the one hand and stationary part 10 of the draw frame 1 on the other hand. In this case, the fan 4 is, where appropriate, to be connected by its intake side, with interposition of a corresponding intake line (not shown), to the intake opening covered by the filter 5 and situated in the cover 2. According to an embodiment of the described device which is preferred and therefore also illustrated in Fig. 2, the fan 4 is flanged to the side wall 20 of the cover 2 as it is in the exemplary embodiment described first; however, in the vicinity of its air outlet side begins the mouth 600 of a pipe 60, which is part of an air-guiding device 6. According to the exemplary embodiment shown in Fig. 2, the mouth 600 is widened in the form of a fimnel which may extend not only in the widening direction parallel to the longitudinal axis of the fan 4 as shown, but additionally also to a greater or lessa" extent in the peripheral direction around the fan 4 as well. The mouth 600 of the pipe 60 thereby catches as much air as desired and guides it through the pipe 60 to the location in the drive space 3 at which the positive pressure is required. In the exemplary embodiment shown, the pipe 60 branches and has two outlet mouths 601 and 602 which are directed towards certain drives (30,31, 32,33,34) and/or towards such regions of the gaps 21 which are only inadequately suppUed with positive pressure on account of their distance from the fan 4 or owing to the complex shape of the drive space 3. The air-guiding device 6 thereby contributes to a uniform distribution of the positive pressure in the region of the gaps 21 and thus guarantees that air is unable to penetrate into the drive space 3 at any point here. Even the above discussions show that the invention is not restricted to the described design, but can have many modifications. Thus, it is of course possible to replace individual or all features of invention by equivalents or else to use them in different combinations, without going beyond the scope of the present invention. For instance, it is not necessary for the air-guiding device 6 to have merely a single pipe 60; if this is expedient, naturally two or more such pipes of simple or complex shape may also be provided. Nor is it necessary for this pipe 60 or these pipes 60 to be closed over their entire length. Since the air fed to the drive space 3 contributes to the cooling, it may in fact be advantageous if particularly r^idly revolving parts or such parts which tend to heat up for other reasons are additionally cooled by air fed directly to them. The pipe outlet openings 603,604,605 and 606 shown in Fig. 2, for example, serve this purpose, in addition to the task of creating a uniform positive-pressure distribution in the drive space 3. The air-guiding device 6 does not necessarily have to have a pipe or pipe system; it is also possible to use one or more air-guiding plates or air-guiding members of a diffffent nature instead of this or possibly also in addition to this. It has already been mentioned above that the fan 4 may be arranged, m principle, at any desired location in the drive space 3, provided that its orientation and/or an appropriately designed air-guiding device 6 is able to ensure a sufficient positive pressure in the drive space 3 in the entire region of the openings and gaps 21. In this regard, it is also irrelevant in terms of its fimctioning whether the fan 4 is carried by the stationary part 10 of the draw fi"ame 1 or in some other way, for example in that it is motionally connected - as described -to the cover 2 (or another cover 2a or 2b). The latter design is particularly advantageous since by swinging open the cover 2,2a or 2b carrying the fan 4, the fan 4 is also swung out of the drive space 3, so that the latter is fi-eely accessible for maintenance. The arrangement of the fan 4 in one comer of the drive space 3 makes little sense, as follows fi'om the above description, since the desired positive-pressure distribution as a rule can be achieved only with greater outiay (more complex air-guiding device). Nevertheless, in a design according to which the fan 4 is carried by a cover 2,2a or 2b, it is advantageous if it is situated not centrally in lie drive space 3 but in the closest possible vicinity of the pivot axis of the respective cover 2,2a or 2b. In the draw fi-ame 1 shown in Fig. 1, the axis (not shown) of the covers 2,2a and 2b is provided in each case in the vicinity of their edges 22, 23 and 24 respectively, which is why, according to the exemplary anbodiment shown here, the fan 4, as is apparent fi^om the illustration of the filter 5, is carried by the cover 2 in the vicinity of the edge 22 thereof. The fan 4 is thus situated in the closest possible vicinity of the centre of gravity of the cover 2, so that the maintenance person is not hindered in his or her work by the weight of the fan 4 when opening and closing the cover 2,2a or 2b. Moreover, the weight, in view of its suspension in the cover 2, can be compensated by an appropriately dimensioned spring or the like (not shown). Since the space surrounding the draw fi-ame 1 is not fi"ee from fibres, fibre fragments and other Ught fly components, the filter 5 becomes clogged in time. It is therefore necessary to clean the filter 5 periodically on its outside. This may be done manually. For this reason, according to the exemplary embodiment of the draw frame 1 shown in Fig. 1, the filter 5 is arranged on the side facing the tending side 16 of the draw frame 1. On this side there is situated, for example, a platform 17 which facilitates the maintenance of the draw frame 1, in particular the accessibility to the drive space 3. If the fan 4 is carried by the cover 2, then the filter 5 is thus situated in the side v^^all 20 of the cover 2. If, in contrast, the fan 4 is not carried by the cover 2, then the filter 5 is arranged in the side v^^all 100 of the draw frame 1. Nowadays, modem textile machines work automatically, so that there is hardly any maintenance work left to be carried out by maintenance personnel. It is therefore desirable for the cleaning of the filter 5 also to be performed automatically rather than manually. To this end, the fan 4 may be assigned a control device 71 (see Fig. 1) for reversing the running direction for a short time. A time of less than 5 seconds is preferably set for this filter cleaning, and a more detailed explanation for this will be given later. The temporary running of the fan 4 in the running direction which is reversed with regard to the normal running direction causes air to be sucked in from the drive space 3 and emitted through the filter 5 into the atmosphere surrounding the draw frame 1, the fleece formed previously on the outside of the filter 5 being blown, and falling, off from the outside of the filter. Such a cleaning may be coupled to certain operations on the draw frame 1, e.g. the exchange of a fiill can 14 for a can 140 already in a waiting position (can change). It may however also be carried out in dependence on the shver length deUvered by the draw frame for depositing into a can 14, for example after about every 10,000 metres of sliver, which corresponds to ^jproximately three can changes. Another alternative for carrying out the filter cleaning is to do this time-dependently, e.g. every 20 minutes. The controUabiUty of the fan 4 is explained below with the aid of Fig. 3. This figure shows - without regard to the spatial arrangement of the individual assemblies - the fan 4, which is connected to the control device 71 with the aid of lines 710. Depending on the type of control desired for the fan 4, this control device 71 has a time-control device 72. The latter has, for example, a first button 720 for controlling the period of time between the individual filter-cleaning operations and a further button 721 for settmg the running duration of the fan 4 in the cleaning direction, i.e. in the direction opposite to the normal direction of rotation during operation. A short blast of air is sufficient to blow off the fleece from the outside of the filter 5. Since the air pressure in the drive space 3 should always be higher than in the region surrounding the drive space 3, m order to ensure that no imdesired fly and fibre components can penetrate into the drive space 3 through the openings and gaps 21, the fan 4 is always driven only for a relatively short time m the filter-cleaning direction, i.e. reversed with respect to the normal running direction during operation. Within this short time of preferably less than five seconds, the positive pressure in the drive space 3 is reduced by only an insignificantly small degree, so that the positive pressure in the drive space 3 is maintained, thereby ruling out penetration of air and impurities into the drive space 3 through the gaps 21. The control device 71 is connected to a further control device 7 which controls the working of the draw frame 1 itself This fiirther control device 7 is connected to the main drive motor 30 via lines 700, to a can-changing device 35 for exchanging a full can 14 for an empty can 140 (see Fig. 1) via lines 701 and to a filter box 18 via lines 702. This connection of the control devices 7 and 71 in terms of control enables the fan 4 to be set in operation whenever the draw frame 1 also begins to run, and to be switched off whenever the draw frame 1 is also stopped. Thus, the positive pressure being striven for is generated in the drive space 3 for the entire working duration of the draw frame 1, i.e. for the entire period of time in which drive assembUes in the drive space 3 are in operation. This procedure of switching the draw frame 1 and the fan 4 on and off is performed with the aid of an operating button 70 connected to the control device 7 by means of hnes 703. It has already been mentioned above that the fleece which forms on the outside of the filter 5 in time is periodically blown off, it bemg possible to control this in various ways. To prevent the fleece from falling to the floor, a fleece-collecting receptacle 50 is assigned to the filter 5 on the outside of the drive space 3 in each case in the exemplary embodiments shown in Figs. 2 to 4. If the fleece is now blown off from the outside of the filter owing to the reversal of the running direction of the fan 4, then the fleece falls on account of gravity into the fleece-collecting receptacle 50, from which it can then be disposed of at the desired time, possibly at fixed intervals of time. As the length of the platform 17 illustrated in Fig. 1 shows, the attendant or maintenance person must be able to walk to and fro along the draw frame 1 in order to be able to reach all the assemblies of the draw frame 1 which are to be maintained. Parts or elements which protrude beyond the outer contour of the draw frame are a nuisance here, since the maintenance person may get caught on them. In order to avoid this, provision is made accordmg to Fig. 1 for the filter 5 to terminate substantially flush with the outside of the draw frame 1. According to Figs. 2 and 4, which each show a fleece-collecting receptacle 50 assigned to the filter 5, this fleece-collecting receptacle is designed so that its outside 500, i.e. its side facing away from the draw frame 1 or the drive space 3 thereof, runs substantially flush with the outside or outer contour of the draw frame 1 or the cover 2 -which after all is a part of the draw frame 1. To this end, the fleece-collecting receptacle 50 is designed as a depression in the side wall 100 of the draw frame 1 or in the side wall 20 of the cover 2. In order to avoid manual emptying of the fleece-collecting receptacle 50, something which is labour-intensive m large plants with a multipUcity of draw frames 1, according to Figs. 2 to 4 the fleece-collecting recqjtacle 50 is connected to a suction line 8. In principle, this suction line 8 may open into the fleece-collecting receptacle 50 in any desired manner (from the side, from below etc.), as shown by a comparison of Figs. 2 and 4 on the one hand and Fig. 3 on the other hand. If the fan 4 is arranged in the cover 2, a simple construction can be achieved by forming the bottom 501 of the fleece-collecting receptacle 50 using an area of the stationary part 10 of the draw frame 1 in the manner as shown in Fig. 4, while the filter 5 and the side walls (see outer wall 500 in Figs. 2 and 4) of the fleece-collecting receptacle 50 are situated on the cover 2. The inlet mouth 80 of the aforementioned suction line 8 is situated in this bottom 501 of the fleece-collecting receptacle 50. Thus, the point of separation of fleece-collecting receptacle 50 and suction line 8 is thereby situated in the plane of separation E betwem the cover 2 and the stationary part 10 of the draw frame 1. It is not necessary for the suction line 8 to be under negative pressure continuously. For reasons of energy saving, it is expedient to generate and maintain this negative pressure only for the duration in which the fan 4 is also rotating in the reversed direction with respect to the normal running direction during operation in order to blow off from the outside of the filter 5 fleece which has formed on the latter. For this reason, provision is made according to Fig. 3 for a shut-off device 9 in the form of a controllable valve to be provided in the suction line 8, the valve being connected in terms of control, with the aid of lines 704, to the control device 71 for reversing the running direction of the fan 4. The negative pressure acting in the suction line 8 prevents the fleece from being blown over the upper edge of the outer wall 500 of the fleece-collecting receptacle 50 witiiout this outer wall 500 having to extend particularly high in relation to the uppo" edge of the filter 5. According to Fig. 3, provision is made for a filter box 18 into which the suction line 8 opens and in which the air is guided through a filter device (not shown) in order to clean the air. Such filter devices are known and generally form as so-called filter boxes a component of a draw frame 1, although this is not a prerequisite and a filter box when one is provided at all may also be designed independentiy of the draw frame 1 and commonly assigned to a multiplicity of textile machines. The device for generating a positive pressure in the drive space 3 for the purpose of avoiding disruptions as a result of penetrating fibres and fly has been explained above in connection with a drive space 3 covered by a hinged cover 2,2a and 2b, but it goes without saying that, to this end, a fan 4 having a filter 5 assigned to it may also be provided, ui the context of the present invention, in another, possibly additional, drive space closable by doors 11 etc. At the same time, where appropriate, for a plurality of drive spaces a single fan 4 having a corresponding pluraUty of air-guiding devices 6 or a single intake location in the outer wall of the draw frame 1 having a single filter 5 for a multiplicity of fans 4 may also be provided. WE CLAIM; 1. A draw frame having a drive device located in a drive space which can be covered by means of a movable cover resting by its edge region upon a stationary part of the draw frame, wherein the drive space accommodates at least one fan having at least one intake and one outlet, the intake of the fan being connected, with the interposition of a filter, to an area outside of the drive space, and the outlet of the fan ending in the drive space. 2. The draw frame as claimed in claim 1, wherein the intake of the fan is connected, with the interposition of a filter, to a suction device of a drafting arrangement or to a fan device of a drive. 3. The draw frame according to claim 1 or 2, wherein the intake of the fan is arranged in the upper and/or lower region of the drive space. 4. The draw frame according to any one of the preceding claims, wherein an air-guiding device is provided in the drive space. 5. The draw frame according to claim 4, wherein the air-guiding device is arranged and oriented such that the fan delivers air within said drive space so that an essentially equal effect is generated uniformly around the edge region of the cover. 6. The draw frame according to any one of the preceding claims, wherein the fan is connected to the cover for movement therewith. 7. The draw frame according to any one of the preceding claims, wherein the fan is arranged in the vicinity of the pivot point of the cover. 8. The draw frame according to any one of the preceding claims, wherein the fan is provided with a control device for reversing its running direction. 9. The draw frame according to claim 8, wherein the control device for reversing the running direction of the fan is connected in terms of control to a further control device of the draw frame. 10. The draw frame according to claim 8 or 9, wherein the control device for reversing the running direction of the fan has a time-control device for controlling the running time of the fan in the running direction which is reversed in relation to its normal direction. 11. The draw frame according to any one of the preceding claims, r *"'-comprising a longitudinal tending side from where maintenance is carried out, wherein the filter is arranged in a wall of the draw frame facing the tending side of the draw frame. 12. The draw frame as claimed in any one of claims 1 to 10, "- ■ comprising a longitudinal tending side from where maintenance is carried out, wherein the filter is arranged in a side wall of the cover. 13. The draw frame according to any one of the preceding claims, wherein the filter is provided with a fleece-collecting receptacle on the outside of the drive space. 14. The draw frame according to claim 13, wherein the filter or the outer side of the fleece-collecting receptacle is flush with the outside of the draw frame. 15. The draw frame according to claim 13 or 14, wherein the fleece-collecting receptacle is connected to a suction line. 16. The draw frame according to claim 13, 14 or 15, wherein the point of separation of fleece-collecting receptacle and suction line is provided in the plane of separation of the cover and the stationary part of the draw frame. 17. The draw frame according to claim 8 and any one of the preceding claims, wherein the suction line is provided with a shut-off device connected to the control device for reversing the running direction of the fan. 18. The draw frame according to any one of the preceding claims, wherein the suction line opens into a filter device. 19. The draw frame according to claim 18, wherein the filter device is a component of the stationary part of the draw frame. 20. A draw frame substantially as herein described with reference to the accompanying drawings.

Documents:

2823-mas-1998 abstract-duplicate.pdf

2823-mas-1998 abstract.pdf

2823-mas-1998 claims-duplicate.pdf

2823-mas-1998 claims.pdf

2823-mas-1998 correspondence-others.pdf

2823-mas-1998 correspondence-po.pdf

2823-mas-1998 description (complete)-duplicate.pdf

2823-mas-1998 description (complete).pdf

2823-mas-1998 drawings-duplicate.pdf

2823-mas-1998 drawings.pdf

2823-mas-1998 form-19.pdf

2823-mas-1998 form-2.pdf

2823-mas-1998 form-26.pdf

2823-mas-1998 form-4.pdf

2823-mas-1998 form-6.pdf

2823-mas-1998 others.pdf

2823-mas-1998 petition.pdf