Device and method for adjusting the work gap between the points of flat clothings and the points of the cylinder clothing of a card

Abstract

A device for adjusting the work gap between the points of the flat clothings and the points of the cylinder clothing of a card, whereby the flat bars being furnished with clothings are led over a partial area of the drum circumference on both sides of the card on sliding surfaces which are being provided with respective convex bent sliding guides, whereby the flat bars are being provided with flat heads, furnished with sliding surfaces, which slide alongside the sliding guides, the sliding guides each are being formed by a bent part and the radial position of the sliding surfaces of the sliding guides in relation to the axis of rotation of the drum is changeable by changing the local position of the parts is characterized in that those parts, each forming the sliding guides, are supported at several discrete supporting points and are shiftably arranged in relation to the supporting points, around the axis of rotation of the drum, whereby the sliding surfaces of the sliding guides, for adjusting the work gap, are movable in radial direction.

Description

[0001] The present invention concerns a device and a method for adjusting the work gap between the points of the flat clothings and the points of the cylinder clothing of a card, whereby the flat bars provided with clothings are led across a partial area of the drum circumference on both sides of the card on respective sliding guides with convex bent sliding surfaces, whereat the flat bars are furnished with flat heads with sliding surfaces, which slide along the sliding guides, where the sliding guides are being formed by a bent part each and where the radial position of the sliding surfaces of the sliding guides related to the axis of rotation of the drum is changeable by changing the local position of the parts.

[0002] Devices of this kind are known in various embodiments.

[0003] For example the old U.S. Pat. No. 528,007 of 23.10.1894 describes a revolving flat card, with which the flat bars provided with flat clothings are fastened to respective endless chains on their ends and are pulled on both sides of the card by means of these endless chains being furnished with sliding guides, so that the clothing points are moved relatively to the clothing points of the drum at a constant distance of this over a partial area of the circumference of the drum and thereby carry out the desired carding work. After the movement along the sliding, guides the flat bars are diverted around a pair of chain wheels and led back to a further chain wheel, which also serves as a diverter, end-up again on the sliding guides, so that they can carry out the desired carding work again with the clothing points of the drum. Thus the flat bars arrive again and again on the sliding guide and carry out carding work repeatedly with the drum.

[0004] At the ends of the flat bars so-called flat heads are present, with sliding surfaces, which slide on the respective sliding guides along the two sides of the card. These sliding surfaces together with the sliding surfaces of the sliding guides determine the distance between the points of the flat clothings and the points of the cylinder clothings. This distance must be adjusted precisely during manufacturing of the card and during new furnishing of the card with clothing, whereby one nowadays aims for carding distances, i.e. distances between the points of the flat clothings and the cylinder clothing within the range of approximately 0.2 mm. Only then high-quality carding work is possible at high production rate of the card.

[0005] During the adjustment of this carding gap, the sliding guide at the card, according to the U.S. Pat. No. 528,007, is being displaced radially in relation to the axis of rotation of the drum, in order to keep the desired carding distance. For this purpose the sliding guides are designed as so-called flex bends, which are, according to the US patent specification, attached at three different points by means of adjustment rods on the side frames of the carding frame. By adjusting the respective adjustment rods which are furnished with left and right-hand threads, the three points at which the adjustment rods engage with the flex bends, can be adjusted in each case radially in relation to the carding frame and therefore to the drum axis, whereby it is to be understood that with the radial adjustment on three circumferentially distributed points, the bending of the flex bends, i.e. the sliding guides, is slightly changed, that is a bending of the flex bends takes place.

[0006] After adjustment of the carding distance along the sliding guides the card can be put into operation. In the course of time wear and tear of the points of the flat clothings and the cylinder clothing occur, so that the carding distance increases in an undesirable manner. In order to work against this enlargement of the carding distance, all adjustment rods can be adjusted together, also in the case of the old U.S. Pat. No. 528,007, in order to readjust the carding distance to the originally set value.

[0007] For this purpose the adjustment rods on their far end, that is not facing the flex bends are not fastened directly to the side frames of the carding frame, but on the respective knee levers, which are rotatably mounted on the side frames of the carding frame. The other arms of the respective knee levers are connected with one another and with an adjusting wheel by respective tie bars, so that by turning of the adjusting wheel, a general adjustment of the knee levers takes place and thus, by means of the adjustment rods of the respective engagement points of the adjustment rods on the flex bends.

[0008] This shows that the basic adjustment is possible via the adjustment rods for each support point of the flex bend, independently of the other support points, and that thereafter a mutual adjustment of all support points of the flex bend can be made, so that the carding gaps are adjusted evenly along the flex bend, whereat, as previously mentioned, the flex bends are slightly bent for adjustment to the changed bending.

[0009] A change of adjustment of the flex bends is not only necessary due to wear of the flat clothings and/or the cylinder clothings, but also after grinding of the cylinder clothing and/or the flat clothings.

[0010] It is actually known to mount a sharpening mechanism onto a card and, after interruption of the carding work, to grind the clothings for example twice or three times during their life span, in order to give the clothing points, both the cylinder clothing as well as the flat bar clothings, a sharp form, which ensures a better quality of the carding work.

[0011] It is also known from various patent specifications, for example the EP-A 0 565 486, to build a sharpening mechanism into a card which is used substantially more frequently during the operation of the card in order to guarantee that the respective clothings remain sharp. This latter possibility has the great advantage that for sharpening of the drum and the flat clothings the card does not have to be stopped, so that production is not impaired. Beyond that it is guaranteed that the clothings always have an optimal sharpness and thus a card sliver with even and high-quality characteristics always produced continuously, which benefits the succeeding yarn production. Furthermore such a sharpening system leads to the fact that the clothings experience an overall longer life span.

[0012] Independently of the fact, whether the clothings are ground only a few times during their life span with a rather larger material removal each time or more frequently with a rather smaller material removal each time, such sharpening procedures lead to changes of the carding distance, whereby the possibility of the radial adjustment of the flex bends allows to always adjust the carding distance correctly.

[0013] Various further proposals were made on how to achieve a radial adjustment of the flex bends.

[0014] For example around 1975 a card was offered by SACM, in which the adjusting of the flat was made on each side of the machine from only one single point by means of two side by side arranged spirals which are shiftable towards each other.

[0015] In this type of design the outer spiral on each side of the card has the form of an elongated, curved wedge with a small wedge angle, whose radially outer surface forms the sliding guide and whose radially internal surface slides on the radially outer surface of the respective internal spiral. The inner spirals also have each the form of an elongated, curved wedge, however, on the radially internal side they are additionally provided with teeth, and can thus be rotated by means of a gear set around the axis of the drum, so that with the co-operation of the radially outer surface of the internal spiral with the respective radially internal surfaces of the outer spirals, the sliding guides on both sides of the card can be adjusted at the same time. Thereby all flats can approach the drum of the card at the same time and/or be moved away from the same. From this arrangement it was also known to slightly offset the drum in relation to the axis of the curved sliding guide in order to provide an “entrance” for the flat chain, i.e. to adjust the carding distance within the zone, where the flat bars at the beginning of the carding path of the drum approach, somewhat larger than towards the end of the carding path, when it leaves the drum in order to return to the beginning of the carding path.

[0016] The same proposal was also again brought forward in the DE 196 51 894A1.

[0017] In connection with the adjustment of the flex bends of a card the DE 29 48 825 A1 is also of interest. In fact it is being recognized that the carding distance can change during operation, and this due to elongations, which are caused by centrifugal force and due to thermal expansions, which occur during warming up or cooling down of the card.

[0018] Such elongations, i.e. due to centrifugal force or thermal cause, are, as is described in more detail in the DE A 29 48 825, particularly problematic during start-up or stopping of the card. As is described, the tendency to increase the production rate of cards on the one hand leads to the fact that the number of revolutions of the processing elements is increased and on the other hand, that the dimensions of the machine cylinders become larger, both the diameter and the working width. With the increased rotary speeds and the increased dimensions an undesired deformation of the cylinders, i.e. bulging caused by centrifugal force can take place whereat said bulging increases gradually.

[0019] It is also explained that in direct connection with the increase of the production rate and of the carding work, there is a further influence to be seen in the tendency to suppress, to a large extent, the exchange of air between the cylinders and the environment for the prevention of dust emissions, whereby the natural cooling of the operating components is made more difficult.

[0020] In the DE-A 29 48 825 is mentioned that the temperature of the cylinders involved during the period of operation increases until a balanced temperature is reached, whereat this rise in temperature causes a change of the dimensions of the cylinders and in particular an enlargement of the diameters of the drum. Both the influence of the centrifugal force and the influence of the temperature rise do not have an immediate effect when starting up the machine, but only after a certain time delay, which, regarding the influence of centrifugal force, takes at least as long as the acceleration time of the elements involved at the card e.g. the tambour.

[0021] According to experience, the influence of the temperature rise, until a balance of temperature has been reached, requires longer periods of operation which can amount to several hours.

[0022] In order to solve the problem the DE-A 29 48 825 describes a method to control the operating condition between two operating components equipped with clothing of points, for example the drum and the revolving flats of a revolving flat card, where a value being directly related to the dimensions of the drum is continuously or temporarily recorded and by means of a suitable regulating device the carding distance is held at a defined value in dependence of the recorded value.

[0023] In the realistic solution shown therein for the adjustment of the flex bends, i.e. the sliding guides, heatable metal bars are applied, which are warmed up either by means of a heatable fluid, the heat being supplied by a heat supplying device, or by way of an electrical heating means and are therefore forced to expand thermally. Since the temperature control makes a relatively exact adjustment of the lengths of the respective metal bars possible, the mechanism described there can work at a high accuracy.

[0024] There are also various other proposals known for the radial adjustment of the flex bends of a card. For example the U.S. Pat. No. 5,625,924 shows a card with different possibilities for the radial adjustment of the sliding guide, amongst other things this disclosure describes the application of controllable actuators, which are specifically controlled in order to periodically adjust the changed carding gap newly or to compensate the wear of the clothings after a sharpening method. Thereby it is expressed that the controllable actuator can be applied and controlled in connection with an integrated sharpening system. Different types of embodiments of the actuator are mentioned. For example the use of servo motors or piezoelectric translators for the executions of the adjustment are mentioned. It is also shown how an eccentric arrangement of a controllable drive mechanism is applicable in order to accomplish a sensitive adjustment.

[0025] Furthermore, from the WO patent application 93/07314 an adjustment system is known with several adjustment devices which are arranged in respective places along the sliding guide and which extend between the sliding guide and a fixed point of reference, whereby each adjustment device is furnished with a blocking mode through which an adjustable clamping mechanism is effective in order to keep a once reached adjustment through blocking.

[0026] Despite the multiplicity of proposals already made these are difficult and complex to realize in practice and/or expensive for manufacturing.

[0027] The extent of the adjustment movements at the individual points of adjustment of the flex bends is indeed relatively small, whereby a total adjustment of more than three to four millimetres is rarely necessary and an adjustment in steps is aimed at of approximately 0.01 mm. Due to such small steps it can easily be seen, that already small clearance spaces in mechanical joints etc., will questions the accuracy of the adjustment. Also adjusting mechanisms which are made with thermal expansions, require a certain control effort and can be impaired by dead play, particularly since the adjustment requires at one time a movement radially outward and at another time a movement radially inward. The problem arises that temperature measurements are actually indirect measurements and direct measurements of the carding distance has proved so far as being relatively inaccurate.

[0028] Furthermore, in the case of adjustable wedge systems, the manufacturing costs are relatively high, since close tolerances must be maintained over a wide range.

[0029] The applicant has also discovered that the applied materials for the sliding guide frequently show a hysteresis, so that the distances for adjustment in one direction are not the same in the opposite direction and for this reason the accuracy of the adjustment also suffers. Additionally the friction forces, which arise with some constructions, are so large, that the resetting forces, which develop due to the tension of the flex bends, are too small in order to guarantee a reliable and precise resetting.

[0030] In some materials a plastic deformation already arises at lower tensions, which likewise leads to an inaccuracy of the adjustment. Moreover, the pre-loadings, which are applied during processing of the flex bends, can have a disturbing effect on the accuracy of the adjustment.

[0031] If windows, which are useful for the flat adjustment, are present in the flex bend, these windows can disturb the maintenance of the constant course of the carding gap in unwanted ways.

[0032] It is thus known to radially adjust the flex bends or sliding guides for the flat bars of a card respectively, for different reasons, which are:

[0033] a) for new adjustment of the carding gap during manufacturing of the card or after renewed clothing of the card, whereby a respective radial adjustment is usual within the range of approximately 2 mm at the various points of adjustment, in order to be able to adjust the carding space along the sliding guide at all points,

[0034] b) to effect a radial adjustment of the sliding guides, in order to hinder the wear of the clothings and to keep the carding space constant, whereat an even adjustment at the respective points of adjustment is desired here, since an even wear is to be expected and the once correctly adjusted carding space only has to be readjusted evenly,

[0035] c) to radially adjust the flex bends, in order to hinder the change of the carding space due to centrifugal force and/or thermal expansion, whereat also this adjustment is to be understood as an even adjustment.

[0036] d) to perform a radial adjustment of the flex bend, in order to counteract a change of the carding distance due to centrifugal force and/or thermal expansion, whereat also this adjustment is to be understood as an even adjustment.

[0037] The adjusting range for all even adjustments (according to b), c) and d)) usually lies within the range of 0,2 to 0.3 mm.

[0038] Finally, in all the previous proposals a buckling of the sliding guides takes place in order to obtain the necessary adjustment of the carding gap, so that the sliding guide is to be regarded as a flexible part, even though it is partially of a very high rigidity.

[0039] In order to effect the adjustment, the individual adjustment devices are supported on comparatively rigid structures, such as the side frames of the carding frame, or on so-called fix bends which in principle also form part of the side frames of the carding frames.

[0040] It is the object of the present invention to provide a device and/or a method of the initially specified type which does not suffer from the stated disadvantages or only has these disadvantages to a smaller extent, which results in a substantial simplification within the area of the sliding guides and which thereby allows substantial cost savings during the manufacturing and operation of the card, whereby an exact adjustment of the carding gap across the entire effective range for all of the existing adjustments is nevertheless to be made possible.

[0041] This task, as an object of the invention, is solved in that the parts forming the sliding guides, each is supported at several discrete supporting points and in relation to the supporting points are shiftably arranged around the axis of rotation of the drum, whereby the sliding surfaces of the sliding guides are movable in radial direction for adjusting the work gap.

[0042] A first concrete possibility to realize the change of the local position of the parts forming the sliding guides, consists of providing each of these parts as an oblong, bent wedge and of realizing the supporting points by fixedly arranged support noses.

[0043] Thus, similar as in the case of the SACM suggestion of the year 1975, the sliding guides are provided as oblong, bent wedges and/or spiral-shaped guides, however to save costs it is done without the second wedge, which co-operates with the wedge-shaped part and/or the respective spiral part. Instead at suitable supporting points fixedly arranged supporting noses are provided. If the sliding guide designed as oblong, bent wedge is shifted around the axis of rotation of the drum and in relation to the supporting noses, then the sliding surface of the sliding guide is shifted in radial direction, whereat a micro-adjustment is made possible according to the above mentioned points b) to d).

[0044] Even if the supporting noses are fixedly arranged, they can be arranged for ensuring of a coarse adjustment and/or a new adjustment according to point a), first being shiftably arranged in radial direction in relation to the side frames of the card and after performance of the coarse adjustment for example by tightening respective clamping screws, whereat they then are not being adjusted any more for the further operation of the card, unless a new coarse adjustment due to a new clothing and/or an exchange of the drum or of the revolving flat is necessary. Since a certain coarse adjustment must be provided in any case and since, based on the invention, one can do without two oblong, wedge-shaped and therefore relatively expensive parts, a substantial simplification and cost effectiveness is achieved through the invention and this in fact without any loss of accuracy of the adjustments.

[0045] Shifting of the oblong, bent wedge around the axis of rotation of the drum can be realized in various ways, as in all the following examples being provided with respective means for movement. For example a controllable piston-cylinder arrangement can be attached at an end of each oblong, bent part, whose piston rod can be shifted outward and/or inward for obtaining the necessary adjustment. Such a piston-cylinder arrangement can also be replaced by a spindle drive arrangement, whereat either the spindle or the spindle nut can be propelled by a stepping motor, in order to provide the necessary adjustment. For the realization of the shift of the oblong, bent wedges, also a toothed section can be provided on the oblong, bent wedge and can be engaged by a pinion being propelled by a stepping motor.

[0046] Instead of realizing the supporting points through fixedly arranged support noses, the supporting points can also be formed by stationary, however rotatably arranged rolls, which rotate around respective axes of rotation, which extend parallel to the axis of rotation of the drum. Such rolls, which are available at reasonable prices in the form of ball bearings, have the big advantage that an exact adjustment with relatively small forces can be achieved, since the rolls unreel for example on the radial inner surface of the oblong, bent parts, so that no substantial friction forces are to be overcome there. Also in such an arrangement the rolls can first be shiftable in radial direction, in order to accomplish a coarse adjustment. For this, e.g. the axle journals, on which the rolls are rotatably mounted, can be arranged in such a way, that they are radially shiftable and can be clamped in relation to the side frames of the card.

[0047] A further possibility to accomplish the desired radial adjustment of the sliding surfaces of the sliding guides, consists of designing the supporting points as rotatable snail-formed cams.

[0048] This embodiment offers the possibility, by adjusting of the respective snail-formed cams, to first obtain the desired coarse adjustment and thereafter to clamp the cams in their respective rotary positions. Thereafter the shifting of the oblong, bent parts, forming the sliding guides, around the axis of rotation of the drum and over the supporting surfaces of the cams is being utilized, in order to perform a fine adjustment according to the points b), c) and d). In order to realize this, the oblong, bent parts must be of wedge shape, to thus effect the necessary radial adjustment at all points along the oblong, bent parts.

[0049] While shifting the oblong, bent parts around the axis of rotation of the drum, the oblong, bent parts, due to the tension of the driving belts for the flat bars, are slightly bent if the supporting surfaces on the supporting points are not resting on a bend, which corresponds with the form of the arch-type form of the oblong, bent part. This can occur above all if the supporting points are being adjusted for performing a coarse adjustment. In order to make sure that the oblong, bent parts nevertheless are supported on all supporting points, they must be sufficiently flexible, that, due to the respective prevailing corresponding forces, they come in contact with all the provided supporting points.

[0050] A further variant of the embodiment with rotatable snail-formed cams consists of furnishing the sliding guides with teeth which comb the snail-formed cams with teeth, whereby a shift of the sliding guides around the axis of rotation of the drum leads to a rotation of the snail-formed cams around their respective axis, running parallel to the axis of rotation of the drum and therefore to a radial shift of the sliding surfaces of the sliding guides.

[0051] For this embodiment it is not compelling necessary that the oblong, bent parts be designed as wedges, but they can have a constant radial thickness, since the radial adjustment of the sliding surface takes place due to the turning of the snail-formed means on the supporting points. The arrangement can also be in such a way that the radial adjustment of the sliding surfaces takes place both due to the turning of the snail-formed means as well as due to the shift of a wedge-shaped oblong part.

[0052] With an arrangement with snail-formed means bein provided with teeth, said snail-formed means can, for the performance of a coarse adjustment according to point a), at first be shifted in axial direction, so that the teeth of the snail-formed means become disengaged from the teeth of the sliding guides of the oblong parts, and then again can be re-engaged with the teeth of the oblong parts, so that a respective radial adjustment at each snail-formed cam is possible. Thereafter, the shift of the oblong parts, forming the sliding guides, around the axis of rotation leads to the fact that a common radial adjustment of the sliding surfaces of the sliding guides on all supporting points takes place at the same time.

[0053] Another possibility to realize the radial adjustment according to the invention consists of designing each sliding guide in such a way, in that at each of those points, which correspond with the supporting points, it carries a step-shaped ramp whose steps, depending upon the respective turning position of the part around the axis of rotation of the drum, work together with the supporting noses forming the supporting points, in order to determine the radial position of the sliding surfaces of the sliding guides.

[0054] In this embodiment the coarse adjustment is accomplished according to point a) by the fact that the part is positioned in such a way in the circumferential direction that the suitable steps cooperate with the supporting points, for example with supporting noses being provided there. Thereafter a small adjustment of the supporting noses can still be necessary, in order to accomplish the coarse adjustment with the desired accuracy, however, a short adjusting distance is sufficient to accomplish the necessary coarse adjustment.

[0055] The fine adjustment according to the points b), c) and d) is then being accomplished by shifting the oblong parts, forming the sliding guides, within a length of the circumference, which corresponds with the length of the individual steps.

[0056] In this embodiment as well the supporting points could be formed by rotatable snail-formed cams, whereby the range of the radial adjustment (fine or coarse adjustment) can be increased.

[0057] This embodiment does not require a wedge-shaped design of the oblong, bent sliding guides, but these can be made with a constant radial thickness—they must only have a sufficient flexibility as has been mentioned above. If the oblong, bent parts are designed as wedges, then the single stage surfaces of the step-shaped ramps form parts of circle-cylindrical surfaces, with a center at the axis of rotation of the drum, since the radial adjustment is then reached by the wedge form of the oblong, bent parts.

[0058] If the sliding guides need to be provided with a constant radial thickness, then the stage surfaces of the step-shaped ramps can be inclined in relation to the circumference surface of the drum, so that the inclined form of the stage surfaces provides the necessary radial adjustment. Of course a mixed solution is also possible, in which both a wedge-shaped design of the oblong, bent parts and an inclined arrangement of the stage ramps are provided, whereby a distinct radial adjustment with a relatively small circumferential movement is possible.

[0059] On the supporting points rotatable supporting members can also be provided, each comprising at least two supporting surfaces, whereat each one has a different radial distance from the axis of rotation of the respective spacer member. By turning the respective supporting members, the supporting surfaces can be adjusted gradually radially in order to achieve at least a coarse adjustment according to point a). If then the axes of rotation of the supporting members are made adjustable within a small radial range, the coarse adjustment can take place with the desired accuracy according to point a). Thereafter the fine radial adjustment is accomplished by adjustment of the present wedge-shaped oblong, bent sliding guides.

[0060] Another possibility exists in the application of supporting members, which comprise at least two supporting surfaces, each of which is designed as a bent ramp, whereby the supporting surfaces merge with one another via respective radial steps.

[0061] In this embodiment the supporting members can be turned to perform the coarse adjustment according to point a) in such a way that the respective attached ramp takes over the supporting function and they can then be turned further or turned back, in order to accomplish coarse adjustment exactly according to point a). Thereafter the fine adjustment is accomplished according to point b) to c) by shifting the wedge-shaped oblong, bent sliding guides. Also in this embodiment there is the possibility to design the oblong, bent parts with a constant radial thickness and perform the fine adjustment according to point a), b) and c) by common rotation of the individual supporting members.

[0062] Another possibility to perform the radial adjustment of the sliding surfaces of the sliding guides according to the invention is accomplished in that each part that formes a sliding guide is designed as two separate sections being arranged behind each other around the axis of rotation of the drum, each of which is connected swivably at its facing ends on a common radially adjustable support and is supported at its respective other remote ends via respective radially adjustable supports.

[0063] In other words, the oblong parts, which form the sliding guides, are in each case designed as two-piece parts. Thereby it is possible to adjust the flat output side separately from the flat intake side, whereby the adjustment takes place here only via radial adjustments at the respective support points. By the dividing the oblong parts into two parts it is made possible, through different radial adjustments at the points of adjustment, to achieve a good adaptation of the desired cylindrical sliding surfaces without the need of deforming the bent parts.

[0064] By way of the common radial adjustment in the center it is being ensured that no steps arise within the sliding surface. In order to provide further remedy here, according to the invention preferably provision is made that the two separate sections of each part within the range of their facing ends overlap themselves and/or engage with one another.

[0065] A further embodiment according to invention consists of furnishing the oblong, bent parts forming the sliding guide, each with a heating device which is able to warm-up the parts over the entire length to fixedly clamp the oblong part at both ends and bend this by the length variation arising due to the thermal expansion and to thus change the radial position of the sliding surface of the respective sliding guides. In this embodiment it is particularly favourable, if the ends of the respective parts are held by respective radially adjustable supports, since then a radial adjustment is to be accomplished both in the center and at the ends.

[0066] A particularly distinct deflection of the oblong parts can be accomplished if these are made as oblong bimetallic strips.

[0067] In such an embodiment it is particularly favourable if the parts forming the sliding guides each is designed as continuous double wedge and has a larger radial depth in the medium longitudinal section than in their respective end sections. In this way it can be ensured that the radial adjustment remains at least essentially constant along each sliding guide. It would, however, also be possible to provide the oblong, bent parts with a constant radial dimension over their entire length, that is, as long as the radial adjustment of individual points along the surface of the oblong parts remains within acceptable limits.

[0068] For preferential embodiments of the invention including the method refer to the patent claims.

[0069] In the following the invention will be described in more detail by way of exemplified embodiments with reference to the drawing, which shows:

[0070] FIG. 1 a schematic illustration of a conventional card,

[0071] FIG. 2 a side view of the card of FIG. 1 within the area of the revolving flat for closer description of the basic embodiment,

[0072] FIG. 3 a schematic cross section within the area of the revolving flat of a card, seen at the cutting plane III-III of FIG. 2, whereby the illustrations of the FIGS. 1, 2 and 3 are shown in different scales,

[0073] FIG. 4 a schematic side view of a sliding guide for a card with a flat head sliding thereon which is designed in accordance to EP-A-0 753,610,

[0074] FIG. 5 a schematic side view of an adjustable sliding guide for a card,

[0075] FIG. 6 an illustration similar to FIG. 5, however referring to a embodiment according to a further invention,

[0076] FIG. 7 a further illustration similar to FIG. 5 of a further embodiment of a sliding guide for a card according to the invention,

[0077] FIG. 8A an illustration similar to the FIG. 5, however on a different embodiment for a sliding guide for a card according to the invention,

[0078] FIG. 8B an enlarged illustration of one of the supporting members of the illustration according to FIG. A,

[0079] FIG. 9A an illustration similar to the FIG. 8A, however with snail-formed design of the supporting members,

[0080] FIG. 9B an enlarged illustration of the snail-formed supporting members of FIG. 9a

[0081] FIG. 10 a side view of a further sliding guide for a card according to the invention, which can, for example, be applied in connection In the embodiment according to FIG. 7, 9 or 11,

[0082] FIG. 11 an illustration similar to the FIG. 5, however of a still further embodiment according to the invention,

[0083] FIG. 12 A schematic side view of a sliding guide for a card, divided into two parts according to the invention, whereby

[0084] FIG. 12B shows a detail in the area of the overlapping ends of the two parts of the sliding guide,

[0085] FIG. 13 a further schematic side view of a sliding guide for a card according to the invention, for which guide the adjustment of the sliding surface is obtained by means of heat supply, and

[0086] FIG. 14 a side view of a further embodiment of a sliding guide for a card according to the invention, which can be applied for example in the embodiment according to FIG. 13.

[0087] The fibre material for carding which can consist of natural fibres or synthetic fibres or mixtures of the same is fed, in the form of dissolved and cleaned fibre flakes, into the filling chute 12, taken over by a licker-in or taker-in 14 as cotton wool, handed over to a tambour and/or a drum 16, and is paralleled by a revolving flat set 18 which is driven over diverting rolls 20, 22, 24, 26 in opposite direction of the direction of rotation 28 of the tambours 16.

[0088] Fibres of the fibre band being on the tambour 16 are then removed by a doffing roller 30 and in an actually known manner they are formed into a card sliver 34 by way of different rollers within the existing discharge zone 32. This card sliver 34 is then deposited by a sliver layer 36 in cycloidal manner into a transportation can 38.

[0089] FIG. 2 and FIG. 3 show the card of FIG. 1 within the zone of the revolving flat chain in a larger scale and in further detail. For simplification of the illustration only a few flat bars 40 are shown all of which consist of a carrying body 42 formed as a hollow profile which carries the flat clothing 44 and two end heads 46 which are fastened to the respective ends of the hollow-profile carrying body, for example in such a way that they fit into the ends of the hollow profile and that they are connected by a squeezing method which is described in detail in the EP-A-627,507 in order to create a positive connection with the hollow profile.

[0090] The actual preferred embodiment of the flat heads 46 and the driving belt 48 which drives them is described in the application EP-A-753 610, whereat the belt can be designed in particular according to FIG. 4 of that disclosure. This embodiment is also shown in further detail in a schematic, perspective illustration of FIG. 4 of the present application.

[0091] The belt 48 is furnished on one side, that is on the internal side in FIG. 2, with teeth 48A, which mesh with teeth 48B on the gear wheels 20 and 26, whereat, for simplification of the illustration, only a few teeth 48A and 48B are shown, it is, however, understood that the entire inside of the belt 48 is furnished with teeth 48A and the entire circumference of the gear wheels 20 and 26 is provided with respective teeth 48B. On the exterior side of the belt 48 there are further, bar-like or girder-like, teeth 49 respectively which are arranged in pairs, whereat here as well, for the sake of simplification, only a few pairs 49 are shown and each pair of teeth 49 engages into a corresponding recess 41 of a respective flat heat, as is being described in more detail in the EP-A 0 753 610.

[0092] One sees from FIG. 2 that the endless driving belts, of which only the one on the side of the cards is being shown here, pull the flat bars 40 from the intake zone 50 on the right side of the drawing across a carding path along a sliding guide 52 which comprises a flex bend 54, up to a discharge zone 56, and that afterwards the flat bars 40 are diverted around the gear wheel 20 by which the driving belt is driven and led back again to the intake zone 50, whereat the driving belt is diverted directly before the intake point 50 around the further gear wheel 26 and is being supported between the two gear wheels 20, 26 by two further wheels 22, 24 and a support means 58.

[0093] It is understood that an arrangement as is shown according to FIG. 2, is also arranged on the other side of the card in an actually known way, whereby the driven gear wheels 20 are driven by a corresponding motor, said motor 61 driven by a control unit 63 only being illustrated schematically, via a common shaft 60, whereat the two gear wheels 20 and therefore the two toothed belts 48, together with the thereon via the pairs of teeth 49 fastened flat bars 40, rotate synchronously, so that the longitudinal axes of the flat bars 40 always extend parallel to the drive axle 62 of the drum 16. This parallel position is always maintained during the movement with the flat chain. Furthermore it is understood that during operation the flat bars 40 are arranged evenly distributed over the entire length of the driving belts 48.

[0094] As is more closely described in the EP-A-753 610, the sliding surfaces 64 of the flat heads 46 lay within the zone of the flex bends 54, in sliding contact with them, that is, on the one hand due to their own weight and on the other hand due to the tension of the belt, which, within the zone of each flat head, generates a radially inward directed force. In other words they get pressed onto the sliding guide 52, i.e. onto the sliding surface 66 of the flex bends 54, on the one hand due to their own weight and on the other hand due to the tension in the driving belts 48. Thereby the necessary carding space A (FIG. 3) between the flat clothings 44 and the cylinder clothing 68 is ensured. Due to the positive engagement of the pairs of bars 49 of the driving belt 48 into the corresponding recesses 41 of the flat heads and due to the synchronized running of the driving belts 48 on both sides of the card, the flat bars 40 are moved synchronously over the two flex bends 54, whereat the longitudinal axes of the flat bars are always led parallel to the drum axis.

[0095] The positive engagement between the driving belt 48 and the flat heads 46 transfers the traction force of the driving belts 48 to the flat bars 40, so that these are moved evenly along the carding path between the intake zone 50 and the discharge zone 56.

[0096] A particular characteristic of the suggestion according to the EP-A-753 610 is based on the fact that within the diverting zone the bars of the pairs of bars 49 of the driving belts 48 tend to spread apart and hold the flat heads 46 in such a way that these are diverted around the gear wheels 20, 26, without the danger of the flat bars 40 being lost and without the need of additional guidance within this zone.

[0097] On the upper side of the revolving flat 18, however, the flat bars 40 are lying loosely on the upper strands of the driving belts; thus they can easily be detached from the driving belt 48, particularly if, for example they need to be cleaned or replaced. The force of gravity makes sure that the flat bars 40 in this zone do not separate from the driving belts 48 in an undesired manner.

[0098] As can be seen from the sectional drawing of FIG. 3, the flex bends 54 of the sliding guides 52 define the carding space A between the flat clothings 44 and the cylinder clothing 68 which, for the simplification of the illustration, is only partially shown in FIG. 3, whereat in this example the sliding guides are furnished with a respective embedded, strip-shaped guiding element 70 made of plastic which forms the sliding surface for the flat heads as is more closely described in the DE-A-39 07 396 or in the EP-A-0 620. In principle, such an embedded element or such embedded elements respectively, being divided into sections, can be applied in all the embodiments being described more closely in the following and, according to the present invention are used to form the actual sliding surface 66 for the flat heads 46 to be used. One can also do without such an element, in particular if the flat head is furnished with a sliding shoe or sliding surface respectively, which usually slides onto the sliding guide made of metal.

[0099] From FIG. 3 it can also be seen that each siding guide 52 is also provided with a radially inner support 72 which is frequently called fix bend, whereat each radially inner support 72 is firmly connected with the respective assigned side frame 74 of the card or is an integral part of it, for example, in the form of a respective cast part. The side frames 74 of the card also carry, in addition, the axis of rotation 62 of the drum (not shown in FIG. 3) and also form a radial guidance for the flex bends 54 (not shown).

[0100] Between each radially inner support 72 and the flex bends 54 assigned to it, there are provided—as can be seen from the FIGS. 2 and 4—lengthwise adjustable, in this example five, mechanisms 76 which, for example, consist of an inner part 78 provided with external thread and an outer part 80 provided as a threaded sleeve with internal thread. By turning the ininner part 78 in relation to the outer part 80, the length of the respective adjusting mechanism 76 can be set and thus a radial adjustment of the flex bends 54 within the zone of the respective supporting area can be accomplished. Thereby the curvature of the respective flexible flex bends 54 can be adapted to the curvature of the drum and the radial position of the sliding surface 66 of the respective flex bends 54 can be set in such a way that the carding space A remains constant over the entire length of the carding path and over the entire width of the drum or—if desired—that it has a desired course along the carding path.

[0101] In the following description parts, which correspond with the parts described so far, are identified with the same reference numerals, however increased by the basic figures 100, 200 etc. in order to make a clear distinction. It is understood that the foregoing description also applies to parts which have the same end-numerals, so that this description does not have to be repeated. That is, the following description concentrates on the deviating characteristics.

[0102] FIG. 5 shows, in a side view a first embodiment according to the invention of a sliding guide 152 which is designed as oblong bent wedge which has a larger radial dimension at its right end of 153 than at its left end of 155, whereby the sliding guide 152 has a constant wedge angle over its entire length. In this example the wedge 152 is supported on three supporting points 157, all of which are formed by fixedly arranged supporting noses 159 each of which is fixedly bolted with two clamping screws 161 onto the side frame of the card.

[0103] At the right end of the sliding guide 152 there is an adjustment device in the form of a piston-cylinder unit 163 whose cylinder is supported on one end 165 on the side panel of the card and whose piston rod 167 is connected on the right end side 153 of the sliding guide 152. The adjustment device 163 is laid out for shifting of the sliding guide 152 around the axis of rotation 175 of the drum according to the double arrow 169.

[0104] By shifting according to the double arrow 169 the radial position of the upper surface of the sliding guide 152 can be changed between the two indicated positions 171 and 173.

[0105] For performing of the coarse adjustment according to point a) above, the clamping screws 161 can be loosened and the supporting noses 159 be shifted in radial direction according to the arrows 181. After tightening of the clamping screws 161, the card can be put into operation and possible necessary micro-adjustments, according to the points b), c) and d) above which are required during the operation, can be performed by shifting of the sliding guide 152 according to the double arrow 169. Although there is a piston-cylinder unit 163 for the adjustment being shown here, this illustration is to be understood only as a substitute of several different possibilities. As an adjustment device, for example, a threaded spindle and a spindle nut driven by a stepping motor or a linear electric drive or a pneumatic driving device could be applied. Furthermore a toothed segment (not shown) could be fastened on the sliding guide 152 and could mesh with the pinion which is driven by a stepping motor in order to perform the adjustment according to the double arrow 169.

[0106] The embodiment according to FIG. 6 is very similar to the embodiment according to FIG. 5, thus the same parts are designated here with the respective same reference numerals, however, with the basic number 200 in order to have a distinction in comparison to the embodiment according to FIG. 5. It is understood that the description supplied for FIG. 5 also applies to the correspondingly numbered parts of the FIG. 6, unless explicitely stated otherwise, whereby this convention also applies to all further embodiments, where other basic numbers are applied. The supporting points In the embodiment according to FIG. 6 are here defined by means of rotatable rolls 275 which can, for example, be designed as ball bearings. Each roll 273 is arranged around an axis of rotation 277, designed as an axle journal, to be rotatable in both directions according to the double arrow 279. Each axle journal 277 is arranged radially shiftable in relation to the side frame of the card according to the double arrow 281 in order to perform the coarse adjustment according to point a) above. After the coarse adjustment has been accomplished, then, by shifting according to the double arrow 269, the sliding guide 252 is moved in order accomplish the fine adjustment according to point a), c) and d) above, due to the wedge-shaped design of the sliding guide 252. It is realizes that the axle journals 277 forming the axis of rotation for the rotatable rolls 273 are arranged to run parallel to the axis of rotation 275 of the drum.

[0107] In the embodiment according to FIG. 7 step-shaped ramps 383 are provided on each of the individual supporting points 357 on the lower surface of the sliding guide 352 which are supported by supporting members 359 being furnished with supporting noses. In this embodiment these supporting members 359 are dimensioned somewhat smaller than in the embodiment according to FIG. 5 they are, however, like-wise adjustably mounted with clamping screws 361 on the side frame of the card. After performing a coarse adjustment by changing the radial position of the supporting noses 359 according to the double arrows 381 and following tightening of the clamping screws 361, the sliding guide 352 can be shifted to perform a fine adjustment according to points b), c) and d) above, according to the double arrow 369. Thereby the three step type surfaces of the step-shaped ramp 383 serve as alternative possibilities for the positioning of the sliding guide 352 for the coarse adjustment according to point a) above. The individual surfaces of the steps, as for example 385, lay on a cylindrical surface concentrically to the axis of rotation 375 of the drum. That means that when shifting in the direction of the double arrow alone, the wedge form of the sliding guide 352 ensures the necessary radial shift of the surface of the wedge between the points 371 and 373. It would, however, also be possible to arrange the individual surfaces, like 385, with an inclined surface in relation to the circumferential surface of the drum and to furnish the sliding guide 352 in form of a cylindric part 652 with an at least essentially constant radial thickness according to FIG. 10. With such an arrangement the radial adjustment then takes place only via the step-shaped ramps 363. Also a mixed solution is possible where the step ramp 383 is being furnished with an inclined supporting surface and where the sliding guide 352 is wedge-shaped, so that both parts are responsible for the radial shift of the sliding surface of the sliding guide 352 when being shifted according to the double arrow 369.

[0108] FIG. 8 shows an embodiment which in principle is similar to the one in FIG. 7, with the only difference that supporting members 483 are used here which are rotatably arranged around respective axes of rotation of axle journals 477. Thereby each supporting member 483 is furnished with four differing supporting surfaces 485, (see also FIG. 8B), which in each case have the same radial distance over their entire section length from the imaginary axis of rotation 489 of said supporting members. The supporting members 483 can thus, for performing of the coarse adjustment according to point a), be turned around the axis of rotation 489, i.e. around the axle journals 477 into a position, where the suitable supporting surface 485 is applied. Thereafter, to perform the coarse adjustment exactly according to point a), the axle journals 477 of the supporting members 483 can also be shifted radially according to the double arrow 481 in relation to the axis of rotation 475 of the drum. Due to the wedge-shaped design of the sliding guide 452, and by shifting the sliding guide 452 according to the double arrow 469, the necessary radial adjustment of the sliding surface of the sliding guide between the positions 471 and 473 takes place. Thereby the supporting members 483 can remain either stationary or turn according to the double arrow 485 according to the rotatable rolls according to the embodiment in FIG. 6 and thereby substantially reduce the developing friction forces.

[0109] The FIGS. 9A and 9B in principle show a similar embodiment only that here the supporting members 583 are applied in the form of stepped, snail-formed cams.

[0110] Here one can also select the respective suitable supporting surface 585 for the coarse adjustment according to point a), whereby, beyond that, the ramp-like form of the individual supporting surfaces 585 makes it possible, by turning of the respective supporting members 583 within the angular range of the supporting surface 585 (approximately 90° in the shown illustration), to perform this coarse adjustment very accurately according to point a). Thereafter the supporting members 583 are clamped in their respective turning position and the fine adjustment according to points b), c) and d) is accomplished by shifting the sliding guide 552 according to the double arrow 569. For this purpose the sliding guide 552 here also has the form of an elongated wedge so that, by shifting according to the double arrow 569, the radial outside surface of the sliding guide 552 can be displaced between the ranges 571 and 573.

[0111] Alternatively the sliding guide 652 according to FIG. 10 can be applied. If this takes place, then one can do without the linear adjustment device 563 and the respective turning of the snail-formed cams 583 according to the double arrow 587 is applied in order to perform the fine adjustment according to the points b), c) and d).

[0112] In the embodiment according to FIG. 11 likewise snail-formed cams are used as supporting members 783 which also here are rotatably arranged around respective axle journals 777. Here the outer surface of each snail-formed cam 783 is provided with teeth 789 which are shown in FIG. 11 over only a short portion of the cam surface of the snail-formed cams, however in practice, preferably the entire cam surface of the snail-formed cams is being provided with teeth. These teeth 789 mesh with corresponding teeth 791 on the radially inner side of the sliding guide 752, which are provided there only in sections, which however, can be provided over the entire length.

[0113] By shifting the sliding guide 752 according to the double arrow 769 by way of the adjustment device 763, then, due to the positive combing engagement between the teeth 791 of the sliding guide 752 and the teeth 789 of the snail-formed cams 783, a turn of the snail-formed cams around an axis of rotation defined by the axle journals 777 is effected according to the double arrow 787 with the result that the outer surface of the sliding guide 752 is adjusted between the radial positions 771 and 773.

[0114] In the embodiment according to FIG. 11 the sliding guide 752 is shown as wedge-shaped sliding guide, it can however, be designed in exactly the same way as the sliding guide 652 according to the FIG. 10, if it is provided with the necessary teeth, as is shown here with 791.

[0115] To perform the coarse adjustment the arrangement is preferably carried-out in such a way that the snail-formed supporting members 783 can be shifted in axial direction of the axle journals 777 until the teeth 789 are no more in combing engagement with the flex bend 752.

[0116] Thereafter the snail-formed supporting members can be turned around the axis of rotation of the axle journals 777 and can be reengaged with the teeth 791 of the sliding guide 752 by axial shifting. Thereby the coarse adjustment according to point a) above is performed. The fine adjustment according to the points b), c) and d) takes then place by shifting the sliding guide 752 according to the double arrow 769 which leads to a turning movement of the supporting members according to the double arrows 789.

[0117] In the embodiment according to FIGS. 12A and 12B each sliding guide 852 is provided in the form of two separate sections 852a and 852b following each other around the axis of rotation of the drum, said sections being swivably linked at 895 with each other with their facing ends 853a and 853b on a common radially adjustable support 893. At their far ends 855a and 855b these sections 852a and 852b each are supported via respective radially adjustable supports 897a and 897b. At their respective facing ends the two separate sections 852a and 852b are designed in such a way that they overlap and/or engage into one another with their end portions.

[0118] The arrangement can be accomplished in such a way that for each section at least one further, radially adjustable support is provided (not shown) which however is being provided between the common support 893 and the supports 897a and 897b located at the end of a respective section 852a and 852b.

[0119] With this arrangement the work gap at the cover intake side can be adjusted differently in relation to the work gap at the cover discharge side of the card. The overlapping arrangement within the area of the two ends 853a and 853b as well as the common support 893 and the common adjusting possibility ensure that a gentle transition from section 852b to section 852a can always take place.

[0120] In a further alternative embodiment according to FIG. 13 the oblong, bent parts, forming the sliding guides 952, are furnished each with a heating mechanism 999 which is able to warm-up the part over the entire length. Each oblong part is fixedly clamped on its two ends and bends increasingly due to the length variation arising through thermal expansion, whereby the radial position of the sliding surface of the respective sliding guides 952 is alterable depending upon to heat supply. The heat supply is determined by the control 1001 which is equipped with a temperature sensor 1003 in order to be able to detect whether the sliding guide has reached the desired temperature and therefore the desired degree of bending. If necessary the control 1001 can be provided as a regulation means.

[0121] Instead of supporting the ends 953 and 955 of the sliding guide on stationary supports they can be held by respective radially adjustable supports such as 959. By radially shifting the supports 959 according to the double arrow 981, while simultaneously heating-up the sliding guide 952 the desired radial position can be attained. The middle support 959′ serves here only for the determination of the starting position of the sliding guide 952, but is also adjustable according to the double arrow 981.

[0122] Each part 952 can, if desired, be provided as oblong bimetallic strip where a distinct bend of the sliding guides is attainable at lower temperatures.

[0123] In this embodiment the parts for forming the sliding guides 952 can each be provided as a continuous double wedge as is shown in FIG. 14 with 952′, i.e. in such a way that, within the middle longitudinal area, the sliding guide has a larger radial depth than within each of the respective distant end areas. This design ensures that the sliding guides, when bending due to the heat generation, experience an even radial adjustment over their entire length. Alternatively, the parts for forming the sliding guides can each have a constant radial dimension over its entire length as is illustrated with 652 in FIG. 10.

Claims

1. Device for adjusting the work gap (A) between the points of the flat clothings (44) and the points of the cylinder clothing (68) of a card, whereby the flat bars (40) being furnished with clothings (44) are led over a partial area of the drum circumference on both sides of the card (10) on sliding surfaces which are being provided with respective convex bent sliding guides (152; 252, 352; 452; 552; 652; 752), whereby the flat bars are being provided with flat heads (46), furnished with sliding surfaces, which slide alongside the sliding guides, the sliding guides each are being formed by a bent part and the radial position of the sliding surfaces of the sliding guides in relation to the axis of rotation of the drum (175; 275; 375; 475; 575; 675;775) is changeable by changing the local position of the parts characterized in that those parts, each forming the sliding guides (152; 252, 352; 452; 552; 652; 752), are supported at several discrete supporting points (157; 257; 357; 457; 557; 757) and are shiftably arranged in relation to the supporting points, around the axis of rotation of the drum (175; 275; 375; 475; 575; 675; 775) whereby the sliding surfaces of the sliding guides for adjusting the work gap (A) are movable in radial direction (between 171 and 173; 271 and 273; 371 and 373; 471 and 473; 571 and 573; 771 and 773).

2. Device according to claim 1, characterized in that the parts forming the sliding guides (152) each of them is designed as oblong, bent wedge and, that the supporting points (157) are formed by fixedly arranged support noses (159).

3. Device according to claim 1, characterized in that the parts forming the sliding guides (252) each of them is designed as oblong, bent wedge and that the supporting points are formed by stationary, however rotatable arranged rolls (273) which are rotatable around respective axes of rotation (277) which extend parallel to the axis of rotation (275) of the drum.

4. Device according to claim 1, characterized in that the supporting points (557; 757) are formed by rotatable snail-formed cams (583; 783).

5. Device according to claim 4, characterized in that the parts forming the sliding guides (552; 752) each of them is designed as oblong, bent wedge.

6. Device according to claim 4, characterized in that the parts forming the sliding guides (652) each of them has a constant radial dimension over its entire length.

7. Device according to claim 4, 5 or 6, characterized in that the sliding guides (752) are provided with teeth (791) which comb with teeth (789) of the snail-formed cams (783), whereby a shifting (769) of the sliding guides (752) around the axis of rotation of the drum (775) leads to a turning movement of the snail-formed cams around their axes of rotation (777) running parallel to the axis of rotation of the drum (775) and therefore leads to a radial shift of the sliding surfaces of the sliding guides (752).

8. Device according to claim 1, characterized in that the parts forming the sliding guides (352), where they correspond with the supporting points (357), carry a step-shaped ramp (383) each, whose steps (385), depending on the respective turning position of said part around the axis of rotation (375) of the drum, cooperate with the supporting points (357) being formed by the supporting noses (359) in order to determine the radial position of the sliding surfaces of the sliding guides (between 371 and 373).

9. Device according to claim 8, characterized in that the parts forming the sliding guides each of them has a constant radial dimension over its entire length.

10. Device according to claim 9, characterized in that the supporting points are formed by rotatable snail-formed cams.

11. Device according to claim 8 or 9, characterized in that the surfaces of the steps (385) are inclined in relation to the circumferential surface of the drum.

12. Device according to claim 1, characterized in that on the supporting points (457) rotatable supporting members (483) are provided, whereby each supporting member has at least two (485) supporting surfaces, each with a different radial distance from the axis of rotation (489) of the respective supporting member (483).

13. Device according to claim 12, characterized in that each sliding guide (452) is designed as oblong, bent wedge.

14. Device according to claim 13, characterized that each sliding guide has a constant radial dimension over its entire length.

15. Device according to claim 1, characterized in that on the supporting points (557) rotatable supporting members (583) are provided, whereby each supporting member has at least two supporting surfaces (585) which are designed as a bend ramp each, whereby the supporting surfaces (585) merge via respective radial steps (ΔR) into one another.

16. Device according to claim 14 or 15, characterized in that one or several mechanisms are provided in order to make possible a turning of the rotatable supporting members (483; 583) into the respective desired turning positions.

17. Device according to one of the preceding claims, characterized in that a mechanism (163; 263; 363; 463; 563; 763) is provided in order to shift the parts forming the sliding guides around the axis of rotation of the drum.

18. Device according to one of the preceding claims, characterized in that for each sliding guide (152; 252; 352; 452; 552; 752) of three up to twenty, preferably three to six supporting points (157; 257; 357; 457; 557; 757) are provided.

19. Device for adjusting the work gap (A) between the points of the flat clothings (44) and the points of the cylinder clothing (68) of a card, whereby the flat bars (40) being furnished with clothings (44) are led over a partial area of the drum circumference on both sides of the card (10) on sliding surfaces which are being provided with respective convex bent sliding guides (152; 252, 352; 452; 552; 652; 752), whereby the flat bars are being provided with flat heads (46), furnished with sliding surfaces, which slide alongside the sliding guides, the sliding guides each are being formed by a bent part and the radial position of the sliding surfaces of the sliding guides in relation to the axis of rotation of the drum (175; 275; 375; 475; 575; 675;775) is changeable by changing the local position of the parts characterized in that, each part forming a sliding guide is provided in the form of two sections which follow each other around the axis of rotation of the drum, said sections being swivably linked with one another with their facing ends on a common radially adjustable support and which are supported around their far ends by respective radially adjustable supports.

20. Device according to claim 19, characterized in that the two separate sections of each part within the area of their facing ends overlap and/or engage with one another.

21. Device according to claim 19 or 20, characterized in that for each section at least one further radially adjustable support is provided which is located between the common support and the supports at the end of the respective section.

22. Device for adjusting the work gap (A) between the points of the flat clothings (44) and the points of the cylinder clothing (68) of a card, whereby the flat bars (40) being furnished with clothings (44) are led over a partial area of the drum circumference on both sides of the card (10) on sliding surfaces which are being provided with respective convex bent sliding guides (152; 252, 352; 452; 552; 652; 752), whereby the flat bars are being provided with flat heads (46), furnished with sliding surfaces, which slide alongside the sliding guides, the sliding guides each are being formed by a bent part and the radial position of the sliding surfaces of the sliding guides in relation to the axis of rotation of the drum (175; 275; 375; 475; 575; 675;775) is changeable by changing the local position of the parts characterized in that the oblong bent parts forming the sliding guides (952) are provided each with a heating mechanism (999) which is able to warm-up the parts over their entire length, that each oblong part is fixedly connected on its two ends (953,955) and that it bends through the length variation caused by the thermal expansion and thus the radial position of the sliding surface of the respective sliding guides is alterable.

23. Device according to claim 22, characterized in that the ends (953, 955) of the respective parts (952) are held by respective radially adjustable supports.

24. Device according to claim 22 or 23, characterized in that each part is furnished as oblong bimetallic strip.

25. Device according to claim 22, 23 or 24, characterized in that each of the parts forming the sliding guides (952′) is designed as continuous double wedge and that in the middle longitudinal range they are provided with a larger radial depth than in the respective area at the far end of each of the said parts.

26. Device according to claim 22, 23 or 24, characterized in that the parts forming the sliding guides (952) each have a constant radial dimension over their entire length.

27. Method to adjusting the work gap (A) between the points of the flat clothings (44) and the points of the cylinder clothing (68) of a card, whereby the flat bars (40) being furnished with clothings (44) are led over a partial area of the drum circumference on both sides of the card (10) on sliding surfaces which are being provided with respective convex bent sliding guides (152; 252, 352; 452; 552; 652; 752), whereby the flat bars are being provided with flat heads (46), furnished with sliding surfaces, which slide alongside the sliding guides, the sliding guides each are being formed by a bent part and the radial position of the sliding surfaces of the sliding guides in relation to the axis of rotation of the drum (175; 275; 375; 475; 575; 675;775) is changeable by changing the local position of the parts, characterized in that the parts forming the sliding guides (152; 252, 352; 452; 552; 652; 752) are each supported on several discrete supporting points (157; 257; 357; 457; 557; 757) and are being shifted around the axis of rotation of the drum (175; 275; 375; 475; 575; 675; 775) in relation to said supporting points, in order to move the sliding surfaces of the sliding guides in radial direction for adjusting the work gap.

28. Method according to claim 27, characterized in that on the supporting points (157; 257; 357; 457; 557; 757) supporting members (159; 273; 359; 483; 583; 783) are being adjusted to perform a readjustment and that for performing a micro-adjustment with an even radial adjustment of the sliding surfaces of the sliding guides, the shifting (169; 269; 369; 469; 569; 769) of the sliding guides (152; 252, 352; 452; 552; 652; 752) around the axis of rotation of the drum (175; 275; 375; 475; 575; 675; 775) is being performed.