DE10046916A1 - Adjustment to the working gap between the facing points of the clothing of revolving flats and the carding drum, at a carding machine, has a spring or piezo-electric unit at each flat to set its height - Google Patents

Abstract

To set the working gap between the points of the revolving flat clothing and the peaks of the carding drum clothing, the radial height from the sliding surface (164) for the revolving flat heads (146) is adjusted against the tips of the carding drum clothing. To set the working gap between the clothing of the revolving flats and the carding drum, each revolving flat has an adjustment unit (196) in or on it, to set the working gap between clothings. The adjustment unit can be piezo-electric, with an electrical control, or it can be a pliable spring (196) which is set by the tension of a belt which carries the revolving flats along the sliding surface. The position of the sliding surface, for the revolving flats, can be altered to adjust the radial gap between the clothing peaks of the revolving flats and the carding drum. An Independent claim is included for a system to adjust the working gap between the points of the revolving flat and carding drum clothings, with a control unit to set the voltage for the piezo-electric units at each revolving flat from a common voltage supply. Preferred Features: The belt which takes the revolving flats along their sliding path makes contact with an electrical path, as the circuit to supply each piezo-electric unit with electricity at each revolving flat, using contact brushes. The continuous belt for the revolving flats passes around toothed disks and deflection rollers, with an electrical contact for the belts through each toothed disk or deflection roller. Each belt has two contact paths. Where each revolving flat has a pliable spring to set its position, the belt tension to adjust the spring position is determined by a controlled brake, which acts directly or indirectly at a toothed disk where the belt path is deflected. A motor gives a controlled drive to the belt toothed disk, with a control to set the motor power. The revolving flat adjustment spring can be fitted with an oscillation damper. The revolving flat spring is a pliable and elastic plate, held at the revolving flat by a spring clip (190). Or they are leaf springs between a fixed and a moving section of the revolving flat. Each multi-part revolving flat has an exchangeable spacer.

Description

The present invention relates to a method and an apparatus for Setting the working gap between the tips of the cover sets and the tips of the drum set of a card, the one with set Ren provided flat bars over a portion of the drum circumference on both sides of the card on respective, convexly curved sliding guide stanchions and the flat bars have sliding surfaces Have cover heads that slide along the slide guides.

Devices of this type are known in various designs.

For example, the old US patent 528007 describes October 23, 1894 a revolving flat card, in which the with flat sets provided flat bars at their ends on respective endless chains are attached and by means of these endless chains over on both sides the card provided slide guides are pulled so that the Gar nitur tips relative to the clothing tips of the drum and in one constant distance from this over a portion of the circumference of the Drum are moved and thereby the desired carding work lei sten. After moving along the sliding guides, the covers are removed rods deflected around a pair of sprockets and returned to a white teren sprocket, which also serves as a deflection point, and get onto this Point again at the sliding guides so that they again with the clothing tips  the drum can perform the desired carding work. Consequently the flat bars always come back to the sliding guide and perform repeated carding with the drum.

At the ends of the flat bars there are so-called lid heads, have the sliding surfaces on the respective sliding guides on the slide on both sides of the card. These sliding surfaces determine with the Sliding surfaces of the sliding guides the distance between the tips of the Lid sets and the tips of the drum sets. This Ab has to stand during the production of the card and when re-garnishing the card de can be set exactly, whereby carding distances, d. H. Clearances between the tips of the cover sets and the drum strives in the range of about 0.2 mm. Only then is one high valuable carding work possible with high card production.

When setting this carding gap, the sliding guide at Card according to US-PS 528 007 radial with respect to the axis of rotation of the drum adjusted to maintain the desired carding distance. To this Purpose are the slide guides designed as so-called flex arches, the in the US patent in three different places by means of adjusting rods ben are attached to the side frame of the card frame. By ver position of each as a threaded rod with left and right hand threads trained adjustment rods can be the three points at which the adjustment Grasp the bars on the flex bend, each opposite the card frame and therefore the drum axis can be adjusted radially, to be understood is that by the radial adjustment on three circumferentially distributed Points the curvature of the flexbows, d. H. of the sliding guides, minor gig is changed, d. H. the flex bends are bent.  

After setting the carding distance along the sliding guides the card is put into operation. Over time there will be an ab use of the tips of the cover sets and the drum set, see above that the carding distance undesirably increases. To the counteracting enlargement of the carding distance can also in the old US patent 528007 all adjusting rods ver together be put to the carding distance to the originally intended Value attributed.

For this purpose, the adjustment rods are removed from the flex bend ends did not directly face the side frames of the carding machine stells attached, but on respective arms of angle levers that turn bar on the side frame of the card frame. The others Arms of the respective angle levers are with each other and with an adjusting wheel connected via respective connecting rods, so that by rotating the Adjusting wheel a common adjustment of the angle lever and thus over the adjustment rods of the respective points of attack of the adjustment rods on the Flex bends are made.

From this you can see that the basic setting by the adjusting rods for each support point of the flexbow independent of the other ab bases is possible and that afterwards a common adjustment all support points of the flexbow can be made so that the carding gaps are adjusted evenly along the flex bend, whereby, as already mentioned, the flexbows to adapt to the changed Curvature can be bent slightly.  

A change in the setting of the flex bends is not only when it is worn the cover sets or the drum sets required, but even after grinding the drum set or cover set.

It is namely known to mount a grinding device on a card and, after the carding work has been interrupted, during the lifespan he grinds the sets twice or three times, around the tips of both the drum set and the lid rod sets to give a sharp shape for better quality the carding work.

It is also from various patents, for example the EP-A-0 565 486 discloses installing a grinding device in a card s which are much more common and during the production of the Carding machine is used to ensure that the respective trimmings stay sharp. This latter possibility has the great advantage that Grinding of the drum and cover sets did not stop the card must be so that the production is not affected. About that it also ensures that the trimmings are always optimally sharp have and therefore always a card sliver with uniform and high valuable properties is produced, which the subsequent Garnher position benefits. Furthermore, such a grinding system leads to that the sets have a longer life overall.

Regardless of whether the trimmings were only a few times during their life Life with greater material removal or more often with each Such grinding processes result in less material being removed to change the carding distance, with the possibility of radial  Adjustment of the flex bends always allows the carding distance to be correct adjust.

Various other suggestions have been made on how to make a radial Adjustment of the flex arches can achieve.

For example, a card was put on by the SACM company in about 1975 by adjusting the lids on each side of the machine a single point by means of two contiguous and opposite mutually displaceable spirals.

With this construction, the outer spiral points on each side of the card the shape of an elongated, curved wedge with a small wedge angle on whose radially outer surface forms the sliding guide and whose radial inner surface on the radially outer surface of the respective inner spiral slides. The inner spirals also have the shape of a langge stretched, curved wedge, but are also on the radial inside Ren side with teeth and can thus by means of a tooth Radpaares are rotated about the axis of the drum, so that by the Cooperation of the radially outer surface of the inner spiral with the respective radial inner surfaces of the outer spirals the sliding guides can be adjusted on both sides of the card at the same time. here through all the lids can be the drum of the card at the same time approach or be removed from the same. It was also known to the This arrangement, the drum against the axis of the curved slide easy to move the guide to prevent the cover chain from entering create, d. H. the carding distance in the area where the flat bars are Approach the drum at the beginning of the carding path, slightly larger than at the end of the carding path when they leave the drum,  to then return to the beginning of the carding path the.

The same proposal was also made new in DE 196 51 894 A1.

DE 29 48 825 A1 is also in connection with the adjustment of the Flex arches of a card of great interest. There it is recognized that the carding decency can change during operation, both due to strains caused by centrifugal force as also due to thermal expansions that occur when heating up or Cool down the card.

Such strains, i.e. H. due to centrifugal force or thermal ursa Chen are, as explained in DE-A 29 48 825, especially in In Commissioning or switching off the card is problematic. As explained there tert leads to a tendency to increase the production rate of cards on the one hand that the speed of the processing elements is increased and on the other hand that the dimensions of the machine cylinders are larger both the diameter and the working width. Due to the increased speeds and the enlarged dimensions undesirable deformation of the cylinders, i. H. their through the run due to bulging, which gradually increases.

It also explains that another, with the increase in Pro production rate and thus the card work directly related Influence in the tendency can be seen, the air exchange between the Zy alleviate and the environment to prevent dust emissions far going to suppress, thereby reducing the natural cooling of the working area ment is difficult.  

DE-A 29 48 825 expresses that the temperature of cylinders involved increases over time until one Equilibrium temperature is reached, this temperature increase a change in the dimensions of the cylinders and in particular a ver increases the diameter of the drum. Both the influence of Centrifugal force and the influence of the temperature rise do not have any effect immediately when starting up the machine, but only after one certain time lag which, as far as the influence of centrifugal force is concerned, at least as long as the acceleration time of the elements involved, in the card z. B. the drum.

The influence of temperature rise until an equilibrium temperature experience has shown that it lasts over many longer operating periods which can be several hours.

In order to remedy this, a process is described in DE-A 29 48 825 to control the employment relationships between two with a top cooking only equipped working elements, such as the drum and the The revolving lid of a revolving card, described in which one with the dimensions of the drum are directly related the size recorded continuously or temporally and the carding distance through a suitable regulation depending on the detected size is held at a certain value.

In the concrete solution shown there, the Flex is adjusted arches, d. H. of the sliding guides, heated metal rods used either by means of a heatable by a heat supply device Fluids or an electric heater warmed up and therefore to one thermal expansion can be caused. Because the temperature control  a relatively precise adjustment of the lengths of the respective metal rods possible, the device described there with a high Ge work accuracy.

Various other suggestions are also known for radial ver position of the flex arches of a card. For example, the US Pat. No. 5,625,924 a card with various radial options Adjustment of the sliding guide, among other things, describes this font Application of controllable actuators that are controlled separately, to periodically readjust the work elements and change the Carding gap due to the wear of the sets or after a Compensate grinding process. It is expressed that the controllable actuator in connection with a built-in Grinding system can be used and controlled. There are various dene versions of the actuator specified. For example, the An application of servo motors or piezoelectric translators for the Implementation of the adjustment mentioned. It also shows how an ex Center arrangement used by a controllable drive mechanism bar to make a sensitive adjustment.

For the rest, an adjustment system is known from WO 93/07314, with several adjustment devices, which at respective points along the Sliding guide are arranged and which are between the sliding guide and extend a fixed reference point, each adjustment device also has a locking mode in which an adjustable clamping device is effective to a setting once reached by clamping to keep.  

Despite the large number of suggestions already made, these are listed in Pra xis difficult to implement and expensive to manufacture.

The extent of the adjustment movements at the individual adjustment points the flexbow is relatively small, with an overall adjustment of More than three to four millimeters is rarely required, and an adjustment tion in steps of approximately 0.01 mm. Because of such small steps can easily be seen that already small game clear the accuracy of mechanical joints and the like Question the adjustment. Adjustment devices that use thermi stretches require a certain amount of control effort and can be affected by dead play, especially the setting sometimes a movement radially outwards and sometimes a move radial inward direction. The problem arises that tempera ture measurements are indirect measurements and direct measurements solutions of the carding distance have so far proven to be relatively imprecise.

The manufacturing costs are also relative for adjustable wedge systems high, especially since close tolerances are maintained over a wide range have to.

It has also been found by the applicant that the mate used materials for the sliding guide often have a hysteresis, so that the The ways of delivering and putting away are not the same and the exact due to this fact. Are also with man Chen constructions the frictional forces that occur, so large that the Restoring forces that arise due to the tension of the flexbend are small in order to ensure proper restoration.  

With some materials, a pla static deformation, which also leads to an inaccuracy of the adjuster lung leads. The pre-stresses that occur when machining the Flexbo genes can have a disruptive effect on the Ge have accuracy of the setting.

If there are windows in the flex bend, those for the lid adjustment are useful, they can keep the constant course of the carding gap in undesirably interfere.

It is therefore known to radially adjust the flex bends or sliding guides for the flat bars of a card for various reasons, namely:

• a) to reset the carding gap in the manufacture of the card or after re-garnishing the card, a respective radial adjustment in the range of about 2 mm on the various Adjustment points is common to the carding distance along the sliding to be able to set leadership at all points
• b) to cause a radial adjustment of the sliding guides, from Ab counteracting usage of the sets and the Carding distance to keep constant, with a uniform Ver position at the respective adjustment points is desired because of a uniform wear can be assumed and the one properly set carding distance only has to be adjusted evenly,
• c) to bring about a radial adjustment of the sliding guides in order to the change of the carding distance after grinding the garnit counteracting, although here too only an even night position is required  
• d) to make a radial adjustment of the flex arches to make the changes Carding distance due to centrifugal force or thermal Counteracting stretching, this setting also being called uniform attitude is to be understood.

The adjustment range for all uniform settings (according to b), c) and d)) is usually in the range of 0.2 to 0.3 mm.

In the case of all previous proposals, the Slideways to adjust the carding gap enough so that the sliding guide is to be regarded as a flexible part, too if it is partly very stiff.

The individual adjustment devices are used to effect the adjustment supported on comparatively rigid constructions, such as the sides frame of the card frame or on so-called fixed sheets, which in principle also form part of the side frame of the card frame.

The object of the present invention is a method or a pre to provide direction of the type mentioned in the mentioned suffers from the disadvantages or only to a minor extent, an essential one che simplification in the area of the flexbend brings and makes it possible makes this after carrying out a one-time setting at Manufacture to fix the card or even to execute it only as a fixed sheet ren and thereby significant cost savings in manufacturing and ensure during operation of the card, with an exact setting of the Carding gap over the effective range of the total available Adjustment should nevertheless be made possible.  

In order to solve this problem, the procedure is such that the Setting the working gap by changing the radial height of the Sliding surfaces of the lid heads with respect to the tips of the respective Dec Kelgarnitur is carried out. Preferably in or on each lid head provided an adjusting device, the radial height of the on the working gap is set.

By providing an adjusting device in or on the lid head Flat bars succeed in making a significant simplification in the area of To reach Flexbogen. This can only be done once at the Production of the card exactly in relation to the axis of rotation of the drum be aligned, for example so that the convex curved Slideways concentric with or in relation to the axis of rotation of the drum arranged on an imaginary, concentric to the axis of rotation of the drum Neten circle are arranged wedge-shaped, so that the working gap between a cover set and the drum set along the length the sliding guide becomes increasingly smaller in a manner known per se. All Settings of the working gap afterwards can be made by On positions on the adjustment devices of the respective cover heads are successful gene.

After it is possible with modern processing machines, the kon vex curved slide guides on the side frame of the card centric to the axis of rotation of the drum or with a desired Aus to produce the direction relative to the axis of rotation precisely, you could even on do without the so-called flex bow and only with a fixed bow ar the convex curved sliding surfaces for the flat bars having.  

Basically, there is the possibility of removing the cover heads in two parts form and either one part of the lid head in a series of different radial thicknesses related to the axis of rotation of the drum to deliver and select the appropriate part to the radial height to determine the working gap, taking the two parts of the lid head then firmly screwed together or otherwise attached. al Alternatively, individual spacers of a selected thickness can be used between the two parts of the lid heads.

This type of adjustment, which is used for the above mentioned cases a), b) and c) can be used in the sense compared to the previous Ver drive easier because they are replaced by replacing spacers half the card can be done, using a teaching that the position of the clothing tips of the drum is taken into account, which in turn from the outside, possibly after removing a flat bar, relative without further notice exactly in relation to the radial position of the convexly curved sliding guide can be measured.

Even if it is considered necessary to work with flex arches, which have to be set once during the production of the card, represents the use of adjustment devices described above Kind of a significant simplification compared to the recruitment of the From time to time.

Since there are no particular restrictions on the thickness of the Ab available pieces, this type of adjustment can be used for both Coarse adjustment as well as fine adjustment can be used, provided through precise machining of the sliding guides it is ensured that these  concentric to the axis of rotation of the drum or the desired Po position with respect to the axis of rotation of the drum.

However, it is with the use of spacers of fixed dimensions not possible to make the setting so that in operation on centrifugal forces or thermal changes in work gap can be taken into account so that the working gap is always con remains constant.

To solve this subtask, you can ar with lid heads in which each adjustment device is a piezoelectric trical device that is used to determine the radial height of the Lid head is adjusted electrically.

Since piezoelectric devices are known, the adjustments from to allow to a few millimeters (for example, describes DE-A 198 33 782 a piezoelectric adjustment device in the form of a Drive arrangement for a print head, the adjustments in the area of up to 2 mm), allows the use of piezoelectric adjustment devices and the implementation of the rough adjustment according to point a) as well as settings according to points b), c) and d). However, the implementation of the rough adjustment according to point a) means possibly that each piezoelectric device is separate must be controlled to different adjustments at each ensure the lid heads.

Although this is possible in principle, it is somewhat complicated in reality tion. However, these complications can be avoided if the piezoelectric adjustment device in combination with a spacer  is used, because the spacers can each individually the setting according to point a).

The fine adjustment according to points b), c) and d), which is only in one Be range of about 0.2 mm can be done with a piezoelectric equipment can be easily reached, it being possible to adjust all piezoelectric adjustment devices together exposed that the convexly curved guide surfaces from the outset by one-time setting or by precise editing the ge desired relative position with respect to the axis of rotation of the drum sen.

If the adjustment to be made on each lid head is identical is with the adjustment that is desired on any other lid head can such piezoelectric devices from a common Voltage source via a common control unit with the required Chen voltage are fed.

Another possibility of adjusting an adjustment device according to the invention Realizing is to do this as a compliant facility ren, whose radial height with respect to the axis of rotation of the drum through Change the tension of the straps that is set to move the cover heads are provided along the slide guides.

In the simplest case, such an adjustable device can be used tion is a spring, the degree of compression of the respective spring can be changed by the belt tension. To the Rie To change the voltage, a controllable brake can be provided be that at one of the deflection points of the endless belt directly or indirectly attacks the lock washers provided there.  

If it is the motor that drives endless belts the toothed washers, is a type of engine that always trying to deliver a constant drive power, it suffices with to operate such a controllable brake. However, if the drive performance of the engine decreases with increasing load, it can also be advantageous to control the drive power of the engine also ge stalten, so that in interaction with the controllable brake the Rie mens tension in the area of the convex curved sliding guides and there forth also the degree of compression of the spring constant and a can be kept adjustable.

The invention is explained in more detail below by way of example only of embodiments with reference to the drawing shows:

Fig. 1 is a schematic representation of a conventional carding machine,

Fig. 2 is a side view of the card of Fig. 1 in the region of the revolving flat to further illustrate the basic design,

Fig seen. 3 is a schematic cross-section in the region of the revolving flat of a card to the sectional plane III-III of Fig. 2, wherein the representations of Fig. 1, are shown in different scales 2 and 3,

Fig. 4 is a schematic side view of a sliding guide for a de Kar with a sliding lid thereon head formed according to EP-A-0753610,

Fig. 5 is an end view of a cover similar to the head of Fig. 4, but according to a first embodiment of the invention,

Fig. 6 is a view similar to FIG. 5, but partially in cross-section designed, of a variant of a cover head of the invention with built-in spring as an adjusting device,

See Fig. 7 is a side view of a cover head of Fig. 6 in the direction of arrow VIII,

Fig. 8 is a plan view of the spring of the cover head in accordance with Figs. 6 and 7,

Fig. 9 is a view corresponding to Fig. 6, but vibration damper of a wide ren inventive embodiment with a oscillations,

Fig. 10 is a view similar to Fig. 4, but with a fiction, modern design of the cover head using a piezoelectric adjustment device,

Fig. 11 is a possible modification represent a partially sectional, enlarged view of the cover head in accordance with FIG. 10,

Fig. 12 is a plan view of the piezoelectric adjustment element of Fig. 11 and

Fig. 13 is an enlarged side view of the lid of the head Fig. 10.

Fig. 1 shows a side view of a per se known revolving flat card 10 , for example card C50 of the applicant in a schematic representation.

The fiber material to be carded, which may consist of natural fibers or synthetic fibers or mixtures thereof, is fed in the form of dissolved and cleaned flakes into the filling shaft 12 , taken over by a beater or pusher 14 as a wadding template, a drum or a drum 16 passed and parallelized by a revolving cover set 18 which is driven via deflection rollers 20 , 22 , 24 , 26 in the opposite direction to the direction of rotation 28 of the drum 16 .

Fibers from the nonwoven fabric located on the reel 16 are then removed from a take-off roller 30 and formed in a manner known per se in an outlet section 32 consisting of different rollers to form a carding belt 34 . This card sliver 34 is then abge from egg ner sliver 36 in a transport can 38 in a cycloidal manner.

Fig. 2 and Fig. 3 show the card of Fig. I in the area of the revolving cover set on a larger scale and in further detail. For the sake of illustration, only individual flat bars 40 are shown, all of which consist of a support body 42 designed as a hollow profile, which carries the cover assembly 44 , and two end heads 46 , which are attached to respective ends of the hollow-like support body, for example so that they end used of the hollow profile and by a squeezing process, which is described in detail in EP-A-627 507, positively connected to the hollow profile.

The specific preferred embodiment of the cover heads 46 and the drive belt 48 driving them is described in EP-A-753 610, where the belt can be formed in particular according to FIG. 4 of this document. This training is also shown in Fig. 4 of the present application in further detail in a schematic, perspective view ge.

The belt 48 is equipped on one side, namely on the inner side in FIG. 2, with teeth 48 A which engage with teeth 48 B on the toothed pulleys or gear wheels 20 and 26 , only a few teeth 48 being shown for the sake of illustration A and 48 B are shown, but it is ver that the entire inside of the belt 48 with teeth 48 A and the entire circumference of the gears 20 and 26 is provided with corresponding teeth 48 B. On the outside of the belt 48 there are further, bar-like teeth or bars 49 , which are arranged in pairs, here also for the sake of clarity only individual pairs 49 are shown and each pair of teeth 49 engages in a corresponding recess or cavity 41 of a respective cover head , as described in more detail in EP-A-0 753 610.

It can be seen from Fig. 2 that the endless drive belts, only one of which is shown on one side of the card here, the flat bars 40 from an entry point 50 on the right side of the drawing via a carding path along a slide guide 52 , the one Flex bend 54 includes, pull up to a discharge point 56 and that the flat bars 40 are then deflected around the gear 20 driving the drive belt shown and returned to the entry point 50 , the drive belt being deflected around the further gear 26 immediately before the entry point 50 and is supported between the two gear wheels 20 , 26 by two further support wheels 22 , 24 and a support 58 .

It is understood that an arrangement as shown in Fig. 2 is also on the other side of the card in a conventional manner, the driven gears 20 by a common shaft 60 from egg nem corresponding, only schematically shown motor 61 with control tion 63 are driven, whereby the two gears 20 and therefore the two toothed belts 48 with the attached to it over the pairs of teeth 49 th flat bars 40 rotate synchronously, so that the longitudinal axes of the decel bars 40 always extend parallel to the drive axis 62 of the drum 16 . This parallel position is always maintained when moving with the cover chain. It is also understood that in operation Dec kelstäb 40 are arranged evenly distributed over the entire length of the drive belt 48 .

As is described in more detail in EP-A-753 610, the sliding surfaces 64 of the cover heads 46 lie in the area of the flexible sheet 54 in sliding contact with the latter, on the one hand due to their own weight and on the other hand due to the belt tension, which is radial in the area of each cover head generates inward force. In other words, on the one hand, due to their own weight, and on the other hand, they are pressed against the sliding guide 52 , ie, against the sliding surfaces 66 of the flexbend 54 , by the tension in the drive belt 48 . This ensures the required carding distance A ( FIG. 3) between the cover threads 44 and the drum set 68 . Due to the positive engagement of the pairs of bars 49 of the drive belts 48 in the corresponding openings 41 of the cover heads and due to the synchronized rotation of the drive belts 48 on both sides of the card, the flat bars 40 are moved synchronized over the two flex arches 54 , the longitudinal axes of the flat bars 40 always are guided parallel to the drum axis.

The form-fitting engagement between the drive belt 48 and the lid heads 46 transmits the tensile forces of the drive belt 48 to the flat bars 40 , so that they are just moved along the carding path between the entry point 50 and the exit point 56 .

In this embodiment, according to the present teaching, ben the gear 26 and mounted on the axis 81 , a brake disc 25 and a brake caliper 27 are provided, which can be controlled by a controller 29 so that a controlled braking force on the toothed wheel 26 (and over the axis 182 ) on the corresponding gear on the other side of the card, whereby the belt tension on both sides of the card and therefore the contact pressure between the dec heads and the sliding guides 66 can be determined, as will be explained in more detail later.

A special feature of the proposal according to EP-A-753 610 is that in the region of the deflection, the beams of the pairs of beams 49 of the drive belts 48 tend to spread apart and hold the cover heads 46 so that they are held around the gears 20 , 26 are redirected without the risk that the flat bars 40 hen hen and without additional guides are necessary in these areas.

On the upper side of the revolving cover 18 , however, the flat bars 40 lie loosely on the upper runs of the drive belts; they can thus be easily detached from the drive belt 48 if, for example, they are to be particularly cleaned or replaced. Gravity ensures that the flat bars 40 do not undesirably separate from the drive belt 48 in this area.

As can be seen from the sectional drawing of FIG. 3, the Flexbö gene 54 of the slide guides 52 ensure that the carding distance A between the cover sets 44 and the drum set 68 , which are shown only in sections in Fig. 3 and Fig. 4 , wherein the slide guides in this example are equipped with a respective recessed, band-shaped guide element 70 made of plastic, which forms the sliding surface for the cover heads, as in DE-A-39 07 396 or in EP-A-0 620 296 in more detail is described. In principle, such a recessed element or recessed elements divided into sections can be used in all the embodiments described in more detail below in accordance with the present invention to form the actual sliding surface 66 for the cover heads 46 . However, such an element can also be dispensed with, in particular if the cover head is provided with a sliding shoe or sliding block which slides onto the sliding guide, which is usually made of metal.

From Fig. 3 it can also be seen that each slide guide 52 also has a radially inner support 72 , which is often called a fixed arc, each radially inner support 72 is fixed to the associated Be tenrahmen 74 of the card or integrally ausgebil det with this is, for example in the form of a respective casting. The side frames 74 of the card also support the axis of rotation 62 of the drum (not shown in Fig. 3) and also form a radial guide for the flex bends 54 (not shown).

Between each radially inner support 72 and the flex bends 54 associated therewith are - as can be seen from FIGS . 2 and 3 - in this example, five length-adjustable devices 76 which, for example, consist of an inner, externally threaded part 78 and an outer part 80 formed as a threaded sleeve with an inner thread. By turning the inner part 78 relative to the outer part 80 , the length of the respective adjusting device 76 can be adjusted in each case and thus a radial adjustment of the flexbend 54 can be carried out in the region of the respective support point. As a result, the curvature of the respective flexible flex sheets 54 can be adapted to the curvature of the drum and the radial position of the sliding surface 66 of the respective flex sheets 54 can be adjusted so that the Kardierab stood A over the entire length of the carding path and over the entire width of the drum remains constant or - if desired - has the desired course along the carding path.

In the following description, parts that correspond to the parts described so far are identified with the same reference numerals, but increased by the basic numbers 100 , 200 etc. in order to bring about a clear decision. It goes without saying that the previous description also applies to parts which have the same last end digits, so that this description need not be repeated. That is, the following description focuses on the different features.

FIG. 5 shows, in an end view, approximately in the direction of arrow V in FIG. 4, a cover head 146 , which is also provided with a cavity 141 for receiving the tooth pairs 49 of the drive belt.

In this embodiment, a spring clip 190 is provided with two spring-loaded legs 192 which engage in respective undercuts 194 in the side parts 147 of the lid head 146 . Due to the inclined flanks of the undercuts 194 , the spring clamp 190 tries to always slip upwards in FIG. 5 and in this way holds a plate-shaped spacer 196 between its lower region 198 in FIG. 5 and the underside 199 of the main body of the main body Lid firmly attached.

The spring clip is in this embodiment of at least substantially constant cross-section and extends in the direction perpendicular to the illustration of FIG. 5 over a length which corresponds at least substantially to the width B of the slide guide 52 .

It can be seen straight away that by using different spacers 196 , which also have a width perpendicular to the plane of the drawing in FIG. 5 and which at least essentially corresponds to the width B of the sliding guide 52 , the distance A can be readjusted. The spring clips can be easily loosened or removed to replace the spacers 196 . In this example, the underside of the spring clip 190 forms the actual sliding surface 164 of the cover head and can be provided with a hard surface or with a sliding coating for this purpose. Otherwise, there is the possibility (not shown in FIG. 5) of making the spring clip 190 slightly hollow in the bottom region 198 , so that two flat or curved sliding surfaces corresponding to the previous sliding surfaces 64 of the cover head are created, and this thus provides a stable position on the curved sliding guide 52 assumes.

In other words, the use of different spacers 196 enables the radial height (with respect to the axis of rotation of the drum) between the tips of the cover sets 44 and the actual sliding surface 164 , that is to say the underside of the spring clamp 190 in this example, to be changed and thereby set the working distance A.

There is a further possibility of adjusting the working distance A in the embodiment according to FIG. 5, namely by using egg nes part 196 with pronounced elastic, resilient properties.

As previously explained, the belt tension leads to a force component which presses the flat heads 146 of the flat bars against the sliding surfaces 66 of the sliding guides 52 . Since this force can be made variable according to the invention, one can also determine the degree of compression of such spring elements 196 and thus also the working distance A.

If a controllable brake (brake disc 25 , brake caliper 27 and control 29 ) is used according to FIG. 2, then depending on the contact pressure of the brake caliper 27 on the brake disc 25 , which is determined by the control 29 , the belt tension and therefore the size of the in the radial direction acting on the cover heads Kraftkom component can be determined.

If the drive motor 61 is a type of motor that always tries to maintain a predetermined speed and therefore increases the drive torque in accordance with the respective load in order to comply with the given rotational speed, no special control is required for the drive motor 61 , except for one Control that ensures the required speed (if the speed is one of the parameters that can be specified).

However, if it is a type of engine that responds to changing loading with changing speed, so that it is difficult to achieve the belt tension solely via the controllable brake, it may be advantageous to switch off the drive motor 61 with a controller 62 provide a constant drive torque at constant speed, for example by changing the amplitude of the voltage applied to the motor or by controlling the drive current.

It can thus be seen that the degree of compression of the spring elements 196 can also be changed by increasing the belt tension.

The embodiment according to FIGS. 6, 7 and 8 also uses spring elements, but here in the form of leaf springs 296 , which are arranged between a fixed part 300 and a movable bar 302 of the cover head 246 , to the left and right of the pairs of teeth 49 of the endless belt 48 receiving cavity 241 . Each movable part 302 of the lid head 246 is slidably guided on the shaft part 304 by two guide bolts 306 for the purpose of displacement in accordance with the double arrow 308 . The threaded part 301 of each guide pin 306 is screwed into the fixed part 300 of the cover head 246 , so that a shoulder of the guide pin bears firmly against the fixed part 300 . In contrast, the head part 303 of each guide pin is accommodated in a circular recess 305 of the movable part 302 . In this example, the underside of each movable bar 302 forms the sliding surface 264 of the cover head in the region between the depressions 305 .

Between the movable beams 302 and the fixed part 300 there is a gap 307 , in each of which a spring element 296 bent in the manner of a leaf spring is accommodated, each leaf spring 296 having two openings 309 designed as elongated holes, through each of which one of the guide bolts 306 protrudes. In this way, the springs are held captive and can be freely compressed or stretched to the desired extent without being prevented from the corresponding movements by the guide bolts 306 .

Here too, the degree of compression of the spring elements 296 is influenced by the belt tension. This means that the radial height h of the gap 307 is determined via the belt tension and therefore also the working distance A.

FIG. 7 also shows the part 311 of the flat head which is received within the hollow section 42 of the flat bar 40 . One can also see in Fig. 7 the recess 313 , which takes up the band part of the belt and ensures that the lid heads are guided laterally by the endless belts.

FIG. 9 shows an embodiment which is very similar to the embodiment according to FIGS. 6 to 8, which is evident from the reference numerals used. The only difference here is the provision of a friction lining 315 on the lateral regions of the fixed part 400 , which are opposite the movable beams 402 . The friction linings 315 have an energy-absorbing effect and prevent vibrations in the springs from leading to changes in the working distance A. Instead of attaching the friction linings 315 to the fixed part 400 , they could alternatively be attached to the movable beam 402 . If desired, spacers (not shown) can be inserted into the gap spaces, either to carry out the setting a) or to compensate for possible differences in the spring properties.

The embodiment according to FIGS. 10 to 13 shows an alternative formation from a lid head 446 , which here also consists of two parts, namely a part 500 fastened to the hollow support 442 of the flat bar and thus designated as a fixed part and a movable part or bar 502 which is connected to the fixed part 500 via a piezoelectric adjustment device 496 .

The piezoelectric device 496 here consists of a plurality of piezoelectric layers which change in thickness by applying a voltage and hereby bring about the desired change in the radial height of the sliding surfaces 499 of the lid head 446 with respect to the clothing tips of the flat bar 40 . In order to produce this voltage difference, a voltage is applied to one side of the piezoelectric device 496 via a conductor track 519 , which is integrated in the endless belt 448 and extends at least in places continuously through the belt, while the other side of the piezoelectric device 496 and the slide guides 52 of the card are grounded.

One can even use the lid heads for the electrical connection between the conductor 519 and the piezoelectric device A 496 and between the piezoelectric device 496 and the sliding guide 52, the parts 500 and 502nd Alternatively, wires as shown at 523 can be integrated into the lid head to avoid voltage losses that might occur depending on the material of the lid head.

It is also possible, as shown in FIG. 11, to provide particularly conductive coatings or coverings in the region of the sliding surfaces 466 and in the region of the contact point with the line track built into the endless belt 448 .

It is also possible to install two conductor tracks 519 in the endless belt, which are then insulated from one another (since the endless belt is partly made of plastic) and to provide the voltage supply for the piezoelectric device 496 via these two conductor tracks.

Since the conductor track is provided on both sides of the endless belt 519 , one can on the inside of the endless belt for contacting with the voltage source or with the control device which determines the magnitude of the voltage and therefore the amplitude of the dimensions of the piezoelectric device 496 Contact is made to the conductor track. This can be done, for example, via brush contacts or corresponding conductive areas can be provided on the gears, which are themselves connected to a voltage source or to a control unit via brush contacts.

When areas of gears are used for voltage transmission be, it must be ensured that the corresponding areas ge are isolated from the remaining areas to short circuit avoid.  

It can be seen from FIG. 12 that the piezoelectric device is N-shaped in plan view corresponding to the shape of the lid head 446 . One notices au ßerdem from Fig. 13, that a gap, which can also be provided with insulation, 500 and 502 of the Dec kelkopfs located between the two parts 446, in order to avoid also short-circuiting.

In all the exemplary embodiments explained so far, the cavity 41 , 141 , 241 , 341 and 441 is open on the outer end face, but is closed on the rear end face by the material of the lid head. However, it is not absolutely necessary to see such a cavity before. It only occurs here because you work with an endless drive belt with pairs of teeth that engage in the cavities. If no cavity is provided, the spring device or the piezoelectric device can be designed differently in order to take into account the respective shape of the lid head. Also, the provision of egg nes, the outer end face of the lid head can be closed, with a correspondingly modified form of Federeinrich device or the piezoelectric device is possible, for example, so that the piezoelectric device 496 of FIG. 12 then has the shape of a rectangle has a rectangular opening in the middle.

Although the piezoelectric device used here as a variety is represented by piezoelectric layers, the piezoelectric Furnishings can be realized quite differently, for example accordingly the already mentioned German patent application 196 51 894 A1. she can then have a completely different orientation in the lid head.

Claims (21)

1. A method for adjusting the working gap (A) between the tops of the cover sets ( 44 ) and the tips ( 68 ) of the drum set of a card ( 10 ), the cover rods ( 40 ) provided with sets over a portion of the drum circumference on both Sides of the card are guided on respective convexly curved sliding guides ( 52 ) and the flat bars have sliding heads ( 146 ; 246 ; 346 ; 446 ) with sliding surfaces ( 164 ; 264 ; 364 ; 464 ) which slide along the sliding guides ( 52 ), characterized in that the adjustment of the working gap (A) by changing the radial height of the sliding surfaces ( 164 ; 264 ; 364 ; 464 ) of the cover heads ( 146 ; 246 ; 346 ; 446 ) with respect to the tips of the respective cover set ( 44 ) is carried out. 2. The method according to claim 1, characterized in that in or on each lid head ( 146 ; 246 ; 346 ; 446 ) an adjustable device ( 196 ; 296 ; 396 ; 496 ) is provided, the radial height of which is set to adjust the working gap , 3. The method according to claim 2, characterized in that each adjustable device is a piezoelectric cal device ( 496 ) which is electrically adjusted to determine the radial height. 4. The method according to claim 2, characterized in that each adjustable device is a compliant device ( 196 ; 296 ; 396 ), the radial height of which is adjusted by changing the tension of the belt ( 48 ) which is used to move the Cover heads are provided along the slide guides. 5. Device for adjusting the working gap (A) between the tips of the cover sets ( 44 ) and the tips ( 68 ) of the drum assembly of a card ( 10 ), the cover rods ( 40 ) provided with sets over a portion of the drum circumference on both sides the card is guided on respective convexly curved sliding guides ( 52 ), the flat bars having sliding surfaces ( 164 ; 264 ; 364 ; 464 ) having flat heads ( 146 ; 246 ; 346 ; 446 ) which slide along the sliding surfaces of the sliding guides, thereby characterized in that with each cover head ( 146 ; 246 ; 346 ; 446 ) the radial height of the sliding surfaces ( 164 ; 264 ; 364 ; 464 ) can be changed with respect to the tips ( 44 ) of the respective cover set. 6. The device according to claim 5, characterized in that in or on each lid head ( 146 ; 246 ; 346 ; 446 ) in its radial height (based on the axis of rotation of the drum) adjustable device ( 196 ; 296 ; 396 ; 496 ) is provided is. 7. The device according to claim 6, characterized in that each adjustable device ( 496 ) is a piezoelectric device. 8. The device according to claim 7, characterized in that the piezoelectric devices ( 496 ) in the respective cover heads ( 446 ) from a common voltage source for setting the working gap (A) are controllable by means of a control unit. 9. Apparatus according to claim 7 or 8, characterized in that endless belts ( 48 ) for moving the flat bars ( 446 ) over the slide guides are provided in a conventional manner, the endless belts each with at least one around the entire length of the endless belt extending conductor track ( 519 ) are provided to ensure the voltage supply to the piezoelectric device, wherein in at least one area of the track of each endless belt, a contact device is provided to ensure electrical contact between the respective conductor track and the voltage source. 10. The device according to claim 9, characterized, that the contact device is a conductive brush is. 11. The device according to claim 9, characterized in that the endless belt ( 48 ) via toothed pulleys ( 20 , 26 ) and order steering rollers ( 22 , 24 ) can be deflected, with a toothed pulley or a deflecting roller serving as contact device for each endless belt. 12. The device according to claim 9 or 10, characterized, that each endless belt has two conductor tracks. 13. The apparatus according to claim 5, characterized in that the adjustable device is a spring ( 196 ; 296 ; 396 ), and that the degree of compression of the respective spring can be changed by the belt tension. 14. The apparatus according to claim 13, characterized in that a controllable brake ( 25 , 27 , 29 ) is provided for changing the belt tension, which directly or indirectly engages the pulleys provided there ( 26 ) at one of the deflection points of the endless belt , 15. The apparatus according to claim 14, characterized in that the drive power of the motor ( 61 ) provided for driving the toothed pulleys ( 20 ) causing the drive of the endless belts ( 48 ) can be controlled. 16. The apparatus according to claim 15, characterized in that a control device ( 63 ) is provided for controlling the power of the drive motor. 17. The apparatus according to claim 13, characterized in that each spring device ( 396 ) is assigned a vibration damper ( 315 ). 18. Device according to one of claims 13 to 17, characterized in that the springs ( 196 ) are flexible, plate-shaped, elastic pieces. 19. The apparatus according to claim 18, characterized in that each plate-shaped piece ( 196 ) is held on the lid head with a spring clip ( 190 ). 20. Device according to one of claims 13 to 17, characterized in that the springs ( 296 ; 396 ) are leaf springs, each between a fixed part ( 300 ; 400 ) of the lid head ( 346 ; 446 ) and one of these is arranged opposite guided displaceable part ( 302 ; 402 ) of the lid head. 21. Device according to one of claims 5 to 20, characterized in that each lid head ( 146 ; 246 ; 346 ; 446 ) is constructed in several parts and a part is designed as an interchangeable spacer ( 196 ).