Abstract:
In an apparatus at a carding machine for grinding a clothing drawn onto a rotating roller, having a carrying device with at least one grinding element and an advancing device serving to set the grinding element against the clothing, wherein the apparatus comprises a biasing device serving for automatically continuing to push forward the grinding element in a contact-making direction during the grinding procedure, the carrying device is attached to the carding machine. In order to make it possible, by simple means, to shorten the time until service-readiness carrying elements adjusted in respect of the spacing b relative to the roller are utilized for adjustment of the biasing device.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   The present application claims priority from German Patent Application No. 10 2005 055 916.6 dated Nov. 22, 2005, the entire disclosure of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   The invention relates to an apparatus at a flat card or roller card for grinding a clothing drawn onto a rotating roller. Some grinding devices have a carrying device with at least one grinding element and an advancing device serving to set the grinding element against the clothing, the apparatus comprising a biasing device serving for automatically continuing to push forward the grinding element in a contact-making direction during the grinding procedure, and the carrying device being attached to the flat card or roller card. 
   When textile fibres are processed, the fibres are oriented and cleaned with the aid of flat cards or roller cards. Those fibre-processing apparatuses comprise at least one roller having a wall in the shape of a circular cylinder and carrying a fibre-processing clothing on its outer wall surface. For fibre processing, the roller is set in rotary motion relative to its cylinder axis. The clothing arranged on the outer wall surface passes through the fibre material and orients it, optionally in co-operation with further processing elements such as, for example, card flats, clearer rollers and the like. Cleaning of the raw material is, furthermore, also achieved by the fibre processing. In order to increase resistance to wear and to improve the quality of the textile fibre material, a so-called all-steel saw-tooth clothing is usually used as the fibre-processing clothing. A clothing of such a kind comprises a saw-tooth wire running on a helical course around the roller having a wall in the shape of a circular cylinder, the saw-teeth of which wire pass through the fibre material. In operation of the above-described wires, considerable wear of the fibre-processing clothing takes place. In addition, contaminants can gather in the region of that clothing. The latter-described problem especially comes to the fore when processing synthetic fibres, in the course of which the fibres can melt and stick to the clothing. Therefore, in order to achieve the desired quality of fibre material, it is necessary for the fibre-processing clothing to undergo processing regularly in order, in the course of that processing, to re-grind the tips of the clothing and/or to remove contaminants from the clothing. 
   In the case of a known apparatus (EP 1 430 997 A), after mounting of the grinding arrangement on the machine frame of a flat card or roller card, the desired orientation of the grinding arrangement with respect to the clothing to undergo processing is first adjusted with the aid of an adjusting screw. By that means, the contact pressure (biasing device) of the grinding element against the clothing is adjusted. The processing arrangement is then lifted up off the clothing by actuating a pneumatic lifting cylinder, the roller together with the clothing is caused to rotate and the processing arrangement is advanced towards the clothing by again actuating the pneumatic lifting cylinder. It is disadvantageous that the biasing of the grinding arrangement has to be adjusted in an additional preparatory step, for which the grinding element is firstly set against the non-rotating clothing. In addition, for adjustment of the biasing device, additional outlay in terms of apparatus and installation is required. It is furthermore disadvantageous that, in the case of mobile use or replacement of the apparatus, the time-consuming adjustment procedure is additionally required. 
   It is an aim of the invention to provide an apparatus of the kind described at the beginning that avoids or mitigates the mentioned disadvantages and that especially is simple in terms of construction and installation and makes it possible to shorten the time until service-readiness for advancing the grinding apparatus and for the grinding procedure. 
   SUMMARY OF THE INVENTION 
   The invention provides a grinding device for grinding a clothing on a rotating roller of a carding machine, comprising:
         a carrying device with at least one grinding element and an advancing device serving to set the grinding element(s) against the clothing; and   a biasing device for automatically continuing to push forward the grinding element(s) in a contact-making direction during the grinding procedure; wherein the grinding device is so arranged that carrying elements of the carding machine adjustable for changing a spacing between the roller and a machine element opposed thereto are utilisable for adjustment of the biasing device.       

   As a result of the fact that carrying elements at the sides, having already defined reference points, are associated with the carrier device having the biasing device for the at least one grinding element, the outlay in terms of apparatus and the time required for service-readiness are substantially reduced. Compared to the known apparatus, separate or additional adjustment of the biasing device is no longer necessary. In especially advantageous manner, the constructionally already predetermined defined spacings at the side parts are utilised for that purpose. 
   Advantageously, the grinding device is so configured and dimensioned that it is interchangeable with a cover element and/or a work element of the carding machine. Advantageously, on both sides of the roller there are provided side parts having carrying elements, the peripheral region of which has in the radial direction predetermined spacings relative to a reference point of the roller, and the carrying device of the grinding apparatus is associated with the carrying elements of the side parts. Advantageously, at least one grinding element is arranged to be displaced, during the grinding procedure, in the direction of a displacement path extending perpendicular to the contact-making device. Advantageously, the biasing device is arranged to be displaced in the direction of the displacement path together with the at least one grinding element. Advantageously, the at least one grinding element has an articulated connection to the biasing device by means of a joint. Advantageously, a universal joint is used. Advantageously, the direction of displacement during the grinding process is reversible. Advantageously, the carrier, together with the biasing device for the at least one grinding element, is arranged to be moved or advanced in the contact-making direction. Advantageously, the biasing device comprises a spring, for example a helical spring. Advantageously, in the direction of the clothing surface to be ground, a plurality of grinding elements are provided. Advantageously, with each grinding element there is associated a biasing device, to which it has an articulated connection. Advantageously, at least one grinding element carries out an oscillating or reciprocating movement back and forth during the grinding process. Advantageously, the carrier is mounted on the extension bends of a flat card or roller card. Advantageously, the position of the extension bends is adjustable in the radial direction, for example by means of adjusting elements, for example threaded spindles. Advantageously, the position of the extension bends relative to the roller is adjustable. Advantageously, the extension bends are mounted on the side parts. Advantageously, the carrying device is mounted on the side screens of the flat card. Advantageously, the carrying device is mounted on a machined surface, for example of the extension bend. Advantageously, the machined surface, for example of the extension bend, has a defined spacing relative to the central axis of the roller. Advantageously, the carrier has, in each of its end regions, a connecting plate or the like. Advantageously, the movement drive of the grinding device is connected to the machine control system of the flat card or roller card. Advantageously, the movement drive encompasses the advancing movement towards and away from the roller. Advantageously, the movement procedure encompasses the longitudinally directed grinding movement. Advantageously, the duration of grinding is adjustable. Advantageously, the duration of grinding is adjustable in dependence on the usage time (time in operation) of the clothing. Advantageously, the duration of grinding is between about 2 and 120 seconds. 
   Advantageously, the plurality of grinding elements, for example grinding stones, are arranged next to one another, for example, are arranged in a row. Advantageously, small gaps (spacings), for example not more than 1.0 mm, are provided between the grinding elements. Advantageously, the grinding elements, for example grinding stones, have a width of from about 15 to 1500 mm, for example, about 50 mm. 
   Advantageously, for the, for example oscillating, movement there is provided an electrical drive element, for example an electric motor; a pneumatic drive element, for example a pneumatic short-stroke cylinder; or a hydraulic drive element. The drive element is advantageously mechanically coupled to the roller drive. 
   Advantageously, the inner carrier member, to which the grinding elements are attached, is accommodated and guided in an attachment member. Advantageously, the grinding element is attached to a guide pin. Advantageously, the grinding elements are movable across the width of the work at the same time as the movement member. Advantageously, the carrier is an extruded member, for example of aluminium. Advantageously, the attachment member is an extruded member, for example of aluminium. Advantageously, the dimensions of the carrier and of the cover element or work element are the same or substantially the same. The grinding device may be employed in mobile use. The grinding device may be employed in stationary use. The grinding element may be employed in stationary use. The grinding element may be employed in the shape of a parallelogram, of a parallelepiped (rectangular), or of square shape. Advantageously, the plurality of grinding elements are arranged at an angle with respect to the longitudinal axis of the carrier. Advantageously, the grinding elements overlap one another in the grinding direction. Advantageously, the roller is the cylinder of a flat card or roller card; a licker-in of a flat card or roller card; or a doffer of a flat card or roller card. Advantageously, the machine surface, for example of the extension bend, has a defined spacing relative to the circle of tips of the clothing of the cylinder. 
   The invention also provides an apparatus at a flat card or roller card for grinding a clothing drawn onto a rotating roller, having a carrying device with at least one grinding element and an advancing device serving to set the grind element against the clothing, wherein the apparatus comprise a biasing device serving for automatically continuing to push forward the grinding element in a contact-making direction during the grinding procedure, and wherein the carrying device is attached to the flat card or roller card, wherein carrying element adjusted in respect of a spacing relative to the roller are utilised for adjustment of the biasing device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagrammatic side view of a flat card having a grinding apparatus according to the invention; 
       FIG. 2  shows part of a side screen together with a part of an extension bend, on which a grinding apparatus according to the invention and a fixed carding element are mounted; 
       FIG. 3  is a diagrammatic side view of a part of the card showing a side screen together with a flexible bend, cylinder, extension bend, fixed carding elements and a grinding apparatus according to the invention; 
       FIG. 4  shows an extension bend together with threaded adjusting spindles and a grinding apparatus according to the invention; 
       FIG. 5   a  is a sectional side view of a grinding apparatus according to the invention, wherein the grinding elements and the cylinder clothing are out of engagement; 
       FIG. 5   a   1  is a detail, to an enlarged scale, of the apparatus of  FIG. 5   a;    
       FIG. 5   b  is a top view of and a partial section through the grinding apparatus of the invention according to  FIG. 5   a;    
       FIG. 5   c  is a sectional view, from the front, through the grinding apparatus of the invention according to  FIG. 5   a;    
       FIG. 6  is a sectional view, from the side, through the grinding apparatus of the invention according to  FIG. 5   a , but with the grinding elements and the cylinder clothing in grinding engagement; and 
       FIGS. 7   a  to  7   d  show four practical forms of arrangement for a plurality of grinding elements. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a flat card, for example a TC 03 (Trade Mark) flat card made by Trützschler GmbH &amp; Co. KG of Mönchengladbach, Germany, having a feed roller  1 , feed table  2 , lickers-in  3   a ,  3   b ,  3   c , cylinder  4 , doffer  5 , stripper roller  6 , nip rollers  7 ,  8 , web-guiding element  9 , web funnel  10 , delivery rollers  11 ,  12 , revolving card top  13  having card top guide rollers  13   a ,  13   b  and flats  14 , can  15  and can cooler  16 . The directions of rotation of the rollers are indicated by curved arrows. Reference letter M denotes the centre (axis) of the cylinder  4 . Reference numeral  4   a  denotes the clothing and reference numeral  4   b  the direction of rotation of the cylinder  4 . Reference letter B denotes the direction of rotation of the revolving card top  13  in the carding position and reference letter C denotes the return transport direction of the flats  14 . Between the licker-in  3   c  and the back card top guide roller  13   a  there are arranged immobile cover elements or work elements, for example fixed carding elements  27 ′, and between the front card top guide roller  13   b  and the doffer  5  there are arranged immobile cover elements or work elements, for example fixed carding elements  27 ′′. The arrow A indicates the working direction. The curved arrows drawn inside the rollers denote the directions of rotation of the rollers. Reference numeral  25  denotes a grinding apparatus according to the invention. 
   According to  FIG. 2 , an approximately semi-circular, rigid side panel  18  is fixed laterally at each end of the machine frame (not shown), on the outside of which panel in the region of the periphery there is concentrically mounted an arcuate supporting element  19  (extension bend), for example using screws, which supporting element has, as supporting surface, a convex outer surface  19 ′ and an underside  19 ′′. 
   Carding elements  27 ′ have, at both their ends, supporting surfaces, which lie on top of the convex outer surface  19 ′ of the supporting element. Mounted on the underside of the carding segment  27 ′ are carding elements  20   a ,  20   b , which have carding clothings  20 ′ a ,  20 ′ b . Reference numeral  21  denotes the circle of tips of the clothings. The cylinder  4  has, around its circumference, a cylinder clothing  4   a , for example a saw-tooth clothing. Reference numeral  22  denotes the circle of tips of the cylinder clothing  4   a . The spacing between the circle of tips  21  and the circle of tips  22  is indicated by the reference letter a and is, for example, 0.20 mm. Reference letter b denotes the spacing between the convex outer surface  19 ′ and the circle of tips  22 . Reference r 1  denotes the radius of the convex outer surface  19 ′ and reference r 2  denotes the radius of the circle of tips  22 . The radii r 1  and r 2  intersect in the centre M (see  FIG. 1 ) of the cylinder  4 . 
   The carding segment  27 ′ according to  FIG. 2  consists of a carrier  23  and two carding elements  20   a ,  20   b , which are arranged one after the other in the direction of rotation (arrow  4   b ) of the cylinder  4 , the clothings of the carding elements  20   a ,  20   b  and the clothing  4   a  of the cylinder  4  lying opposite to one another. 
   The grinding apparatus  25  is arranged next to the carding segment  27 ′, seen in the direction of rotation  4   b  of the cylinder  4 . The spring-loaded grinding stone  40  is in grinding engagement with the tips of the cylinder clothing  4   a . An advancing device  33  (see  FIG. 5   a ) brings about displacement of the carrying device for the grinding stone in a radial direction with respect to the cylinder axis M in the direction of the arrows C, D (see  FIG. 2 ), as a result of which the grinding stone is brought into and out of engagement with the cylinder clothing  4   a.    
   In the arrangement shown in  FIG. 3 , between lickers-in  3  and card top guide roller  13   a  there are three immobile fixed carding elements  27   a ,  27   b ,  27   c  and non-clothed cylinder casing elements  28   a ,  28   b ,  28   c . The fixed carding elements  27  have a clothing that lies opposite to the cylinder clothing  4   a . Machine elements, such as the fixed carding elements  27   a  to  27   c , are attached by way of screws and the cover elements  28   a  to  28   c  are attached by way of screws (not shown) to an extension bend  19   a  or  19   b  (in  FIG. 3 , only the extension bends  19   a   1 ,  19   a   2  on one side of the flat card are shown), which in turn is fastened by way of screws onto the flat card panel  18   a  and  18   b  (in  FIG. 3 , only  18   a  is shown) on each side of the flat card. The flexible bends  17   a ,  17   b  (in  FIG. 3  only  17   a  is shown) are fastened by way of screws to the side panels  18   a  and  18   b , respectively. Reference numeral  24   a  denotes the machine frame and reference numeral  30  denotes suction hoods having separating blades. The grinding apparatus  25  according to the invention is mounted between a cover element  28   b  and a fixed carding element  27   b  on the extension bend  19   a   1 . 
   In the arrangement shown in  FIG. 4 , the extension bends (carrying elements)  19   a   1 ,  19   a   2  and  19   b   1 ,  19   b   2  are fastened on each side of the flat card to a flat card panel  18   a  and  18   b , respectively. Each extension bend  19   a   1 ,  19   a   2  and  19   b   1 ,  19   b   2  is—in a manner shown in  FIG. 4  using the example of the extension bend  19   a   1 —adjustable in the radial direction by means of at least three adjusting spindles  29   a   1 ,  29   a   2 ,  29   a   3  (threaded spindles). By this means it is possible to adjust the spacing b ( FIG. 2 ) between the convex outer surface  19 ′ and the circle of tips  22  of the clothing  4   a  of the cylinder. As a result it is also possible to adjust the spacing between the convex outer surface  19 ′ and the centre M (see  FIG. 1 ) of the cylinder  4 . As a result, defined spacings are specified between the peripheral region  19 ′ of the extension bend  19   a   1  and a reference point (circle of tips  22  or centre M). Those defined spacings are utilised for biasing of the biasing device  34  and make separate adjustment of the biasing device unnecessary. The grinding apparatus according to the invention  25  needs only to be set against the clothing  4   a  that is to be ground and/or, as appropriate, to be lifted off therefrom, by means of the advancing device. 
   The spacing a ( FIG. 2 ) between the clothings of the fixed carding element  27 ′ and the clothing  4   a  of the cylinder  4  can also be adjusted by means of the adjusting spindles  29   a   1 ,  29   a   2 ,  29   a   3 . 
   Reference letters f 1  to f 9  denote the widths of the elements mounted on the extension bend  19   a   1 , for example the grinding apparatus  25 , the carding element  27 , the suction hood  30  with separating blade, the widths f 1  to f 9  being the same. The grinding apparatus  25  and a cover element or work element are accordingly interchangeable. It is therefore possible for a cover element or work element to be removed and for a grinding apparatus  25  to be installed in place thereof (exchange). However, it is also possible for the grinding apparatus  25  to be retained permanently mounted on the flat card. 
   In  FIGS. 5   a  to  5   d  there is shown in detail one embodiment of the grinding apparatus according to the invention. 
     FIG. 5   a  shows the cylinder  4 , provided with clothing  4   a , and the grinding apparatus  25 . The grinding apparatus  25  has a housing  31 , in which there are provided a carrying device  32  having grinding elements  40 , an advancing device  33 , a biasing device  34  and a displacement device  47  (see  FIG. 5   b ). Reference letter f denotes the width of the housing  31 . 
   The carrying device  32  comprises a guide member  35  and a carrier member  36 . Mounted at one end of a guide pin  37 , by way of a universal joint  38 , is a grinding stone carrier  39  having a grinding stone  40 . The guide pin  37  is mounted in a through-hole in the guide member  35  so as to be movable in the direction of the arrows F, G. The other end of the guide pin  37  passes through a through-hole  36   a ,  36   b  in the carrier member  36 . A securing ring  41  is attached to the end of the guide pin  37 . The guide member  35  and the carrier member  36  are extruded aluminium members. Reference numerals  46   a   1 ,  46   a   2  denote guide pins (see  FIG. 5   a ). 
   The advancing device  33  comprises a pneumatic cylinder  42  having a cylinder rod  43  (piston rod), for example a pneumatic short-stroke cylinder. To the free end of the cylinder rod  43  there is attached a mechanical transmission element  44 , for example a flat sheet metal plate or the like, which is additionally fixed to the carrier member  36 . As a result of this rigid connection, the cylinder rod  43  and the carrier member  36  are both movable in the same direction. That end face of the cylinder  33  which is remote from the cylinder rod  43  is fixed so that it is supported against the guide member  35 . In accordance with that position of the advancing device  33  which is shown in  FIG. 5   a , a spacing c is present between the grinding element  40  and the cylinder clothing  4   a , that is to say the grinding elements  40  are not in engagement with the cylinder clothing  4   a.    
   The biasing device  34  comprises a helical spring  45 , for example a compression spring, one end of which is supported on a shoulder  37   a  of the guide pin  37  and the other end of which is supported on a step  36   c  in the hole  36   a  through the carrier member  36 . 
   Referring to  FIG. 5   b , the displacement device  47  comprises a pneumatic cylinder  48  having a cylinder rod  49  (piston rod), for example a pneumatic short-stroke cylinder. At the free end of the cylinder rod  49  there is attached a mechanical transmission element  50 , for example a twice-bent sheet metal plate or the like, which is additionally fixed to the guide member  35 , for example by screws  51   a ,  51   b . As a result of this rigid connection, the cylinder rod  49  and the guide member  35  are each movable in the same direction. That end region of the cylinder  48  which is remote from the cylinder rod  49  is fixed so that it is supported against a connecting plate  53   a . The guide member  35  is in the form of an extruded aluminium member, in which, in lateral hollow passageways  35   b ,  35   c , there are adhesively bonded pegs  46 , for example steel pegs of circular cross-section. Extending out from each of the two end faces of the guide element  35  are pegs  46   a   1 ,  46   a   2  and  46   b   1 ,  46   b   2 , which are in the form of guide pins. Sleeves  55   a   1 ,  55   a   2  and  55   b   1 ,  55   b   2  are fixed in bores  54   a   1 ,  54   a   2  and  54   b   1 ,  54   b   2  in the connecting plates  53   a  and  53   b , respectively. The free ends of the guide pins  46   a   1 ,  46   a   2  and  46   b   1 ,  46   b   2  engage in the openings of the sleeves  55   a   1 ,  55   a   2  and  55   b   1 ,  55   b   2 , respectively, in a manner allowing displacement in the direction of the arrows K, L.  FIG. 5   c  shows different spacings d and e between, on the one hand, those end faces of the connecting plates  53   a ,  53   b  that face one another and, on the other hand, the end faces  35   d ,  35   e  of the guide member  35 . By means of the displacement device  47  and displacement of the cylinder rod  49  in the direction of the arrows M, N, the guide member  35  and with it, at the same time, the carrier member  36  are accordingly pushed back and forth in the direction of the arrows K, L. 
   According to  FIG. 5   c , a plurality of grinding elements  40   a  to  40   n , for example grinding stones, are arranged over the width of the grinding apparatus  25  or cylinder  4  next to one another in a row. The spacing g between grinding elements  40   a  to  40   c  arranged one another is, for example, less than 1.0 mm. The duration of grinding governs the amount of material removed from the clothing  4   a  and varies between, for example, 2 and 120 seconds. During the grinding procedure, the grinding elements  40   a  to  40   c  carry out a reciprocating or oscillating movement back and forth in the directions K, L. 
   In the course of advancing (setting against the clothing  4   a ), the advancing device  33  moves in the direction of the arrow G and in the course of the return movement (lifting off from the clothing  4   a ) the advancing device  33  moves in the direction of the arrow F. During movement of the advancing device  33  in the directions F, G, the guide member  35  remains immobile (stationary). In the course of the grinding movement, both the guide member  35  and also the carrier member  36  are moved in the direction of the arrows K, L. 
   With reference to  FIG. 6 , in contrast to what is shown in  FIG. 5   a , the grinding element  40  is in grinding engagement with the clothing  4   a . As a result of actuation of the cylinder  42 , the carrier member  36  is moved in the direction of the arrow I. As a result, the spacing shown in  FIG. 5   a   1  as h, between the carrier member  36  and the guide member  35 , has been reduced to the spacing i. At the same time, the spacing between the securing ring  41  and the carrier element  36  has been increased, compared to  FIG. 5   a , to the spacing k. 
   In the embodiment of  FIGS. 7   a  to  7   d , the grinding surfaces of the grinding elements  40   a  to  40   n  are arranged next to one another in a row. In the embodiment of  FIG. 7   a , the grinding surfaces of the grinding elements  40   a  to  40   n  are in the shape of parallelograms. The adjacent edges of the grinding elements  40   a  to  40   n  form an angle relative to the grinding apparatus P. In the embodiment of  FIG. 7   b , the grinding elements  40   a  to  40   n  are in the shape of parallelepipeds. Those edges of the grinding elements  40   a  to  40   n  which face one another are oriented parallel to the grinding apparatus P. In the embodiment of  FIG. 7   c , the grinding elements  40   a  to  40   n  are in the shape of parallelepipeds. They have a grinding surface having two short edges a and two long edges b, the ratio a:b being equal to 1:2. The angle of the edges γ with respect to the grinding apparatus P is α=45°. In the embodiment of  FIG. 7   d , the grinding surfaces of the grinding elements  40   a  to  40   n  are of square shape and the edges of the grinding elements  40   a  to  40   n  are arranged at an angle α with respect to the grinding apparatus P. 
   Advantageously, the grinding apparatus  25  can be replaced by a functional component such as an MTT cassette of the flat card or roller card, without having to adjust or orient that device relative to the roller (cylinder  4 ). This means that this device can be used for a particular machine and is factory-calibrated. The grinding apparatus has connecting plates  53   a  to  53   b  on the right-hand and left-hand sides, by means of which it can be connected directly to the extension bend  10  or to a machined surface on the side panel  18  of the roller  4 . The spacings of the extension bends  19  with respect to the cylinder  4  are always adjusted for supporting functional components such as an MTT cassette, MTT suction hood and cover members. There is accordingly no need for additional fixing arms or for alignment or preadjustment of the grinding device  35  in the machine. The grinding apparatus  25  is suitable for mobile use and for stationary use in a spinning room machine which has rollers with clothings. Preferably, the device remains in the flat card or roller card and the grinding process is specified by the machine control system. The duration of grinding governs the amount of material removed from the clothing and varies between 2 and 120 seconds. This device has one or more grinding elements  40 , which have a reciprocating or oscillating movement. Preferably, the grinding elements  44  are arranged next to one another in a row, it being possible to produce gaps (spacings) between the grinding elements  40  which are as small as possible (&lt;1.0 mm). The grinding elements  40  preferably have a width of from 15 to 1500 mm; in the preferred arrangement, the width is 50 mm. The grinding stones  40  are accommodated in a guide member  35  and are fixed thereto by means of a guide pin  37  and, in the process, mounted on a universal joint. When the number of grinding elements is &gt;1, an oscillating movement is, because of the gaps, required in the longitudinal direction (in the direction of the width of the work) so that all the teeth of the clothing  4   a  are uniformly re-ground and activated over the width of the work. That oscillating movement can be accomplished by means of an electrical, electromagnetic, pneumatic or hydraulic drive. Mechanical coupling to the cylinder drive or roller drive is likewise possible. A preferred arrangement has a pneumatic short-stroke cylinder in this location. The guide member  35 , to which the grinding elements are fixed by means of the guide pin, is accommodated and guided in a carrier member  36 . The grinding elements  46  can, at the same time, be moved relative to the carrier member  36  and can be advanced towards or moved away from the clothed roller  4  or clothed component. As a result, the grinding procedure can be switched on and switched off. The duration of grinding is dependent on the usage time of the clothing  4   a  and can be varied and controlled. Further preference is given to the grinding device being a part of the machine and the grinding procedure being specified by the control system of the machine. Advantageously, the guide member  35  and the carrier member  36  are extruded members of aluminium, in order to keep down the weight of the components. In addition, the component width f and height (cross-section) correspond approximately to those of an MTT cassette so that, instead of a TwinTop, the grinding device  25  can be installed in a flat card. 
   Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practiced within the scope of the appended claims.