Abstract:
In an arrangement at a carding machine for cotton, synthetic fibres and the like, at least one card top bar has a carrier and card top clothing. The card top clothing is fastened to the card top bar carrier and is positioned opposite to the clothing of a roller, e.g. the cylinder, and at least the regions of the clothing that face the card top bar carrier are made of a ferrous product, especially steel. In order to enable there to be obtained in simple manner a dimensionally stable clothed card top bar and simpler and more rapid reclothing (clothing replacement), at least one magnetic element is present between the card top bar carrier and the regions of the clothing member that face the card top bar carrier.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims priority from German Patent Application Nos. 103 389 47.4 dated 25 Aug. 2003 and 10 2004 033 509.5 dated 10 Jul. 2004, the disclosures of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   The invention relates to a card top assembly for a carding machine. 
   In a known kind of carding machine cotton, synthetic fibres and the like, there is at least one card top bar having card top clothing, the card top clothing being fastened to the card top bar and positioned opposite to the clothing of a roller, e.g. the cylinder, and at least the regions of the clothing that face the card top bar being made of a ferrous product, especially steel. 
   In a known arrangement (U.S. Pat. No. 3,151,362), the card top bar consists of a back portion and a carrier body (carrier) having a foot face. Fastened to the foot face (portion that accommodates the clothing) is all-steel clothing or a clothing strip (flexible clothing) that extends in the longitudinal direction of the foot face. The all-steel clothing consists of a large number of saw-tooth wire portions arranged adjacent to one another. The clothing strip comprises a carrying element consisting of a plurality of textile layers, in which a large number of small wire hooks (clothing tips) are fastened. The regions of the steel clothings that are in each case remote from the tips are associated with the card top bar. The clothing strip is fastened along the longitudinal sides of the carrier body by means of two clamps (brackets, clips). With one end, the clamps encompass the longitudinally oriented edge regions of the clothing strip and with their other end engage in recesses in the carrier body. In practice, the clamps consist of a sheet metal strip, one longitudinal edge of which is cut into the textile material. On assembly, the textile material of the clothing strip is fastened to the carrier body of the card top bar in a positive fit under considerable stress. In the process, the clamps exert tensile forces in such a manner that the textile material is deformed convexly away from the foot face, so that the clothing tips facing outwards are also, undesirably, arranged on a convex-shaped envelope. When not in use, the resulting card top assembly has a precision of 0.05 mm in height and evenness. In use, the differences in height in the assembly increase to approximately 0.2 mm. Sharpening the clothing on the machine improves precision only insignificantly. After a throughput of approximately 400 t of fibre material, the card top clothing is so worn that it has to be replaced. In order to dismantle the sheet metal staples, the card top bar is clamped and the positive fit is reversed by means of a lever and pincers. The considerable forces that occur during assembly and dismantling have a deleterious effect on the dimensional stability of the card top bar. 
   It is an aim of the invention to provide an arrangement of the type described at the beginning that avoids or mitigates the disadvantages mentioned, makes it possible, especially in simple manner, to obtain a clothed card top bar that is dimensionally stable and enables simpler and more rapid reclothing (clothing replacement). 
   SUMMARY OF THE INVENTION 
   The invention provides a card top bar for a carding machine, comprising a card top bar carrier member; a clothing member comprising a ferrous portion; and at least one magnetic element positioned between the card top bar carrier member and said ferrous portion of said clothing member. 
   The solution makes it possible to obtain a simplified seating for the clothing strip (carrier layer and wires arranged in accordance with the setting configuration) on the card top bar, which additionally enables replacement to be made without causing any damage. For example, when the clothing is worn, the clothing strip to be replaced can be removed easily and the undamaged card top bar having the clothing seating according to the invention can be used for a new clothing strip. 
   Advantageously, a magnetic component comprising a said magnet is fastened to the card top bar carrier member. Advantageously, a magnetic component comprising a said magnetic element is fastened by means of an adhesive layer or the like. Advantageously, a magnetic component comprising a said magnetic element is fastened by a screw connection or the like. Advantageously, the or each magnetic element is a permanent magnet, for example is of a permanent magnetic material. Advantageously, the magnetic force is greater than the forces acting upon the clothing member, e.g. carding force, force of a rotating cleaning roller or the like. Advantageously, the clothing member is detachable from the magnetic component. Advantageously, the clothing member is connected to the card top bar by means of the magnetic component as fastening element. 
   Advantageously, the clothing is reversibly detachable from the magnetic component. Advantageously, the clothing, which is set into a backing layer, e.g. fabric or the like, consists of wires or the like that are bent approximately in a U-shape and are so inset that the web portion of the U-shaped wires or the like runs on the reverse side of the backing layer. Advantageously, a compensating layer is present between the card top bar carrier member and the clothing member, which compensating layer is able to compensate for different spacings between the carrier member and the clothing member. Advantageously, the compensating layer is able to compensate for different spacings between the reverse face of the card top clothing member and the foot face of the card top bar carrier member. A compensating layer may be able to compensate for one or more of: different spacings between the sliding surfaces of the card top heads and the foot face of the card top bar; different spacings between the sliding surfaces of the card top heads and the circle formed by the tips of the clothing; different spacings between the circle formed by the tips of the clothing and the circle formed by the tips of the clothing on the cylinder; local different spacings between the reverse face and the foot face. The upper face of the cylinder clothing may constitute a reference surface for the orientation of the card top bar carrier member and of the card top clothing member. The card top bar may form part of a revolving card top. The card top bar may be a fixed carding element. 
   Advantageously, flexible clothing is present. Advantageously, the flexible clothing comprises a carrier and clothing tips, wires, hooks or the like. Advantageously the carrier is strip-shaped. Advantageously, the clothing consists of saw-tooth wire strips, e.g. all-steel clothing. Advantageously, the clothing is mounted on the card top bar carrier member in the region of the foot face. Advantageously, a plastics material, an artificial resin, e.g. epoxy resin, or the like is provided as compensating substance. The card top bar carrier member may be a shape extruded from a light metal, e.g. aluminium. The extruded shape may be a hollow shape. Advantageously, two end pieces (card top heads) are associated with the carrier body. Preferably, the end pieces are pins of hardened steel or the like. Advantageously, the carrier element (textile material) and the compensating layer are arranged in a recess of the foot face (carrier body). Preferably, the recess is limited by at least two lateral webs or the like on the longitudinal sides of the carrier body. 
   Advantageously, the underside of the clothing strip, on which the spines of the bent wires are located, is held securely by means of a magnet fixed to the card top bar carrier member. Advantageously, the clothing strip is additionally fixed laterally to the side faces of the carrier layer, for example by webs mounted on the card top bar carrier member. Advantageously, all the clothing strips, e.g. irrespective of the setting configuration, are arranged to be held flexibly by a magnet, so providing the connection to the card top bar carrier member.
 
Advantageously, the connection is supported mechanically, e.g. by pieces of sheet metal fastened to the card top bar carrier member. Advantageously, there is additional securing or holding of the clothing strip in the horizontal plane e.g. by the clothing strips being held mechanically by webs. Advantageously, two webs are present on the longitudinal sides and/or two webs are present on the transverse sides. Advantageously, a clothing strip is accommodated, to which there is additionally fastened, by way of a compensating adhesive layer, a piece of sheet metal which is brought into contact with the magnet of the card top bar carrier member. Advantageously, the vertical connection is supported mechanically. Advantageously, the clothing strip is additionally provided with e.g. wire claws or the like at its outer edges where there is only carrier layer and none of the wires embedded therein.
 
Advantageously, the magnetic component, e.g. magnetic tape, magnetic strip, magnetic bar or the like, extends in the longitudinal direction of the card top bar. Advantageously, a plurality of magnetic elements is present in the longitudinal direction of the card top bar. Advantageously, the magnetic elements are arranged spaced from one another. Advantageously, the magnetic elements are arranged offset relative to one another. Advantageously, the direction of offsetting is the working direction. Advantageously, a base made from a magnetic material is arranged on the reverse side of the card top clothing member. Preferably, the base is a steel tape, piece of sheet metal or the like.
 
Preferably, the base has on its sides attachments, webs or the like that are bent at an angle. Advantageously, the card top clothing member has at least two groups of clothing, each of which is held by a magnet. Advantageously, at least two groups of clothing each have a heel zone relative to the roller clothing. Advantageously, the card top clothing member consists of a large number of all-steel clothing wires arranged axially relative to the clothed roller, e.g. cylinder. Advantageously, the card top clothing member is held on the card top bar carrier member by at least one magnetic element. Advantageously, the card top bar carrier member consists of a fibre-reinforced plastics material, for example, a glass-fibre-reinforced plastics material is used. Advantageously, a carbon-fibre-reinforced plastics material is used. Advantageously, the magnetic element is integrated in the fibre-reinforced plastics material, for example, by casting the magnetic element integrally with the plastics card top bar carrier member. The magnetic element may be cast or pressed into the plastics card top bar carrier member. Advantageously, the magnetic element is incorporated during manufacture of the plastics card top bar carrier member. Advantageously, at least one and preferably each of the edge regions bordering the longitudinal edges is provided with tips.
 
   The invention also provides a card top bar for a carding machine, having a card top bar carrier member and a clothing member attached to the card top carrier member with an inner surface of the clothing member facing the carrier member, at least a region of the inner surface comprising a ferrous material, wherein at least one magnetic element is provided between the carrier member and the ferrous region or regions of the clothing member. 
   Moreover, the invention provides an arrangement at a carding machine for cotton, synthetic fibres and the like, in which there is at least one card top bar having card top clothing, the card top clothing being fastened to the card top bar and positioned opposite to the clothing of a roller, e.g. the cylinder, and at least the regions of the card top clothing that face the card top bar being made of a ferrous product, especially steel, wherein between the card top bar and the regions of the card top clothing facing the card top bar there is at least one magnetic element. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagrammatic side view of a carding machine comprising an arrangement according to the invention; 
       FIG. 2  shows card top bars with a cut-away view of a slideway and a flexible bend; 
       FIG. 3  is a perspective view of a clothing strip comprising a carrier layer and small wire hooks; 
       FIG. 4  is a side view of a card top bar, in detail, comprising magnetic strip and all-steel clothing; 
       FIG. 5   a  is a side view of a card top bar, as in  FIG. 4  but with the magnetic strip and clothing strip (small wire hook clothing), in the assembled state; 
       FIG. 5   b  is a side view of a card top bar, as in  FIG. 5   a , but with the clothing strip detached; 
       FIG. 5   c  is a cut-away view of a card top foot having two recesses; 
       FIG. 6  is a side view of a card top bar having additional fastening elements for the card top clothing; 
       FIG. 7  is a side view of a card top bar having an additional sheet metal base, for example a steel strip and a compensating layer on the reverse side of the card top clothing; 
       FIG. 8  is a plan view of an integral magnetic strip; 
       FIG. 9  is a plan view of a magnetic element consisting of a plurality of individual magnets; 
       FIG. 10  is a side view of a card top bar having two groups of clothing, each having a heel zone and having two magnets; 
       FIG. 11  is a perspective view of a card top bar comprising a large number of all-steel clothing wires arranged parallel to the axis of the clothed roller; 
       FIG. 12   a  is a side view of a card top bar made from fibre-reinforced plastics having an integrated magnetic element; and 
       FIG. 12   b  shows a portion of the card top bar according to  FIG. 12   a  with card top clothing fastened to the magnet. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   With reference to  FIG. 1 . a carding machine, for example a TC 03 carding machine made by Trützschler GmbH &amp; Co. KG of Mönchengladbach, Germany, comprises 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 , draw-off rollers  11 ,  12 , revolving card top  13  having card-top-deflecting rollers  13   a ,  13   b  and card top bars  14 , can  15  and can coiler  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  denotes the direction of rotation of the cylinder  4 . Reference letter C denotes the direction of rotation of the revolving card top  13  at the carding location and reference letter D denotes the direction in which the card top bars  14  are moved on the reverse side. 
   Referring to  FIG. 2 , a flexible bend  17  comprising a plurality of adjusting screws is fastened laterally by screws to each side of the machine framework. The flexible bend  17  has a convex outer face  17   a  and a lower face  17   b . Above the flexible bend  17  there is a slideway  20 , for example made of a slideable plastics material, that has a convex outer face  20   a  and a concave inner face  20   b . The concave inner face  20   b  rests on the convex outer face  17   a . The card top bars  14 , which are extruded from aluminium, have a carrier body  14   c  and, at both their ends, have a card top foot  14   a  to which there are fastened axially two steel pins  18  which slide on the convex outer face  20   a  of the slideway  20  in the direction of arrow C. The card top clothing  24  is attached to the lower face of the card top foot  14   a . Reference numeral  23  denotes the circle formed by the tips of the card top clothings  24 . 
   The cylinder  4  has around its circumference a cylinder clothing  4   a , for example saw-tooth clothing. Reference numeral  22  denotes the circle formed by the tips of the cylinder clothing  4   a . The distance between the tip circle  23  and the tip circle  22  is denoted by reference letter a and is, for example, 2/1000″. The distance between the convex outer face  20   a  and the tip circle  22  is denoted by reference letter b. The variable radius of the convex outer face  20   a  is denoted by reference letter r 1  and the constant radius of the tip circle  22  is denoted by reference letter r 2 . The radius r 2  intersects the centre M (see  FIG. 1 ) of the cylinder  4 . Reference numeral  14   c  denotes the backs of the card top bars. Reference numeral  19  denotes a clamping element that engages the card top pins  18  and that is connected to the drive belt (not shown) for the card top bars  14 . 
   In the embodiment of  FIG. 3 , the card top clothing  24  consists of clothing tips  26  (small wire hooks) and a carrier element  25  of a textile material. The small wire hooks  26  are approximately U-shaped and are fastened in the carrier element  25  by being pushed through the surface  25 ′. The bent-round regions  26 ′ of the small wire hooks  26  project above the surface  25 ′. The ends of the wire hooks  26 , that is to say the clothing tips, are free. The wire hooks  26  are made of steel wire. 
   In the embodiment of  FIG. 4 , two webs  14   d ,  14   e  are arranged on the card top foot  14   a  laterally in the longitudinal direction, so that in the region of the foot face  14   b  (see  FIG. 5   c ) there is a two-step recess  14   f   1 ,  14   f   2  (see  FIG. 5   b ,  5   c ). As a result, the card top clothing  24   2  is held, protected and embedded. In the upper recess  14   f   1  there is arranged a magnetic element  29 , for example a magnetic tape, magnetic strip, magnetic bar or the like, which is fastened to the foot face  14   b   1  by an adhesive layer  30 . In the lower recess  14   f   2  there is arranged the card top clothing  24   2 , which consists of a large number of saw-tooth all-steel clothing strips  28  that are held in position by a steel cassette  27 . The card top clothing  24   2  is fastened to or held in position on the magnetic element  29  by its region remote from the free clothing tips (teeth). 
   In the embodiment shown in  FIGS. 5   a  and  5   b , the card top clothing  24 , consists of small wire hooks  26  and a carrier element  25  (see  FIG. 3 ).  FIG. 5   a  shows the card top bar  14  and the card top clothing  24 , in the assembled state, the card top clothing or its bent-round regions  26 ′ being held securely by the magnet  29  so that forces acting on the card top clothing  24 , by the carding machine in operation are not able to detach the card top clothing  24 , from the magnet  29 . According to  FIG. 5   b , the card top clothing  24 , has been separated from the magnet  29  and removed from the recess  14   f   21  for example in the event of wear, damage or the like of the clothing hooks  26 . Separation from the magnet  29  can be effected by a suitable tool by means of which the holding magnetic force can be overcome. The separation can also be effected while the carding machine is running in operation during the return of the card top bars  14  on the reverse side (see arrow D in  FIG. 1 ). 
     FIG. 5   c  shows a portion of the two-step recess, recess  14   f   1  having a foot face  14   b   1  and recess  14   f   2  having a foot face  14   b   2 . As can be seen in  FIGS. 4 ,  5   a  and  5   b ,  6  and  7 , the width c of recess  14   f   1  is smaller than the width d of recess  14   f   2 . 
   In the embodiment of  FIG. 6 , two pieces of sheet metal  31   a  and  31   b , for example made from aluminium, are mounted on the longitudinal outer sides of the webs  14   d  and  14   e , the free end regions of which pieces of sheet metal are bent at right angles in opposite directions ( 31   a ′ counter-clockwise and  31   b ′ clockwise) around the lower region of the webs  14   d ,  14   e . In the position shown in  FIG. 6 , the regions that have been bent round  31   a ′,  31   b ′ provide additional holding of the carrier element  25  of the card top clothing  24   1 . Before detachment of the card top clothing  24   1  from the magnet  29 , the end regions are bent open through 90° ( 31   a ′ clockwise and  31   b ′ counter-clockwise). The sheet metal pieces  31   a ,  31   b  can also be formed resiliently in the form of clips. 
     FIG. 7  shows an embodiment of a simplified seating for clothing (magnet  29 ) that additionally comprises a compensating layer  32 , by means of which it is possible to obtain greater card top precision and a larger fastening surface area. The compensating layer  32  is advantageously an adhesive layer, to which a piece of sheet metal  33  or the like, for example a piece of sheet steel, is fastened, which is in contact with the magnet  29 . The magnet  29  is fastened to the card top foot  14   a  by lateral screws  34   a ,  34   b.    
     FIG. 8  shows an elongate strip-shaped magnet  29 . According to  FIG. 9 , the magnetic element consists of a plurality or large number of magnets  29   a  to  29   n.    
   In the embodiment of  FIG. 10 , the tips of the clothing  26  are divided into two groups  26   1 ,  26   2  with two carrier elements  25 , and  252 , respectively. The two card top clothing strips so formed are each fastened to an associated magnetic element  291  and  292 , respectively, for example, by respective adhesive strips  30   1  and  30   2 . The tips of the groups  261 ,  262  are arranged at a tangent to the clothing  4   a  of the cylinder  4  at angles α and β, respectively. In that manner each group has a heel zone (narrowest point between the card top clothing and the cylinder clothing). The card top clothing may have a ground heel portion known per se (not shown) at the narrowest point. The heel zone and ground heel portion may similarly be present in the other embodiments of the invention. 
   In the embodiment of  FIG. 11 , a large number of all-steel clothing wires  35  are arranged parallel to the axial direction, for example, of the cylinder  4 , and are held in position by the magnet  29 . 
   In the embodiment of  FIGS. 12   a  and  12   b  a card top bar  14  is made from a fibre-reinforced plastics material, for example carbon-fibre-reinforced plastics. In the recess  14   f   1  (see  FIG. 5   c ) there is a magnetic tape  29  which is incorporated at the time of manufacture of the card top bar  14  and is thus an integral component of the card top bar  14 . The card top bar  14  can be manufactured, for example, by pressing, drawing, injection-moulding or the like. Provided a mould (matrix) is used, the magnetic strip  29  can be placed into the mould and cast or pressed at the same time. According to  FIG. 12   b , the card top clothing  24   1  is arranged in the other recess  14   f   2  (see  FIG. 5   c ) and is held in position and fixed by the magnetic tape  29 . 
   The invention provides simplified accommodation of clothing on the card top bar  14 , which additionally enables damage-free replacement of the strip. The invention enables simplified seating of the clothing strip (carrier layer and wires arranged according to the setting configuration) on the card top bar  14 , which also allows damage-free replacement. For example, in the event of the clothing being worn, the clothing strip to be replaced can be removed easily and the undamaged card top bar  14  with the clothing seating can be used for a new clothing strip. The underside of the clothing strip, on which the spines of the bent wires are located, is held in position by means of a magnet  29  fixed to the card top bar  14 , and thus the clothing strip is fixed to the card top bar  14  ( FIG. 5   a ,  5   b ). The clothing strip can additionally be fixed laterally to the side faces of the carrier layer, for example by webs mounted on the card top bar  14 , so providing additional securing/holding of the clothing strip in the horizontal plane of movement. All the clothing strips (e.g. irrespective of the setting configuration) are arranged to be held flexibly by a magnet, so providing the connection to the card top bar. If required, the connection is supported mechanically, e.g. by pieces of sheet metal fastened to the card top bar ( FIG. 6 ). Advantageously additional securing/holding of the clothing strip in the horizontal plane is made possible, for example by the clothing strips being held mechanically by way of webs (e.g. two on the longitudinal sides and optionally two on the tranverse sides). Advantageously, in addition to the use of the clothing strips known in the art, it is also possible to use a modified clothing strip to which there is additionally fastened, by way of a compensating adhesive layer, a piece of sheet metal which is brought into contact with the magnet of the card top bar. Advantages of that compensating and fastening layer and of the additional sheet metal piece are that card tops can be manufactured with greater precision and the surface area of the magnetic contact is increased. In that embodiment it is also possible optionally for the vertical connection to be supported mechanically (according to  FIG. 6 ). If required, the clothing strip is preferably additionally provided with e.g. wire claws at its outer edges where there is only carrier layer and none of the wires embedded therein, so increasing the securing of the clothing strip. 
   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 practised within the scope of the appended claims.