Patent Publication Number: US-2004056137-A1

Title: Device for drawing up card clothing

Description:
[0001] The invention relates to a device for winding card clothing onto a roll, with a roll drive unit and a brake device acting on the card clothing for generating a winding pretension in the region of the card clothing between the roll and the brake device.  
       [0002] Clothed carding rolls are produced in that a type of sawtooth wire is wound onto a roll main body. The sawtooth wire lies flat on a feed spool. The device pulls the card clothing off this feed spool. The sawtooth wire is fixed with its free end section on an outer circumferential piece of the roll main body and passes through a braking device at a distance to the roll main body. The roll main body is driven by a closed-loop controlled drive motor. The braking device consists of brake blocks which press onto the side of the sawtooth wire with spring pressure, so that a certain pretension is present between the braking device and the roll main body in the card clothing during the winding process. This device has already been used by the applicant for many years and has proved to be very good. However, attempts are being made to obtain an improvement in this respect.  
       [0003] It is therefore the object of this invention to improve a device for winding card clothing according to the type mentioned at the beginning.  
       [0004] This object is solved according to the invention in that the brake device includes at least one braking roller which presses onto the outer side of the card clothing and runs with it and a brake-force device which generates the braking force, whereby the brake-force device brakes the card clothing indirectly via the braking roller.  
       [0005] Through the application of at least one revolving braking roller, the chances of damaging the card clothing during the winding process are reduced to an extreme minimum.  
       [0006] The applicant has in fact found that occasional recurring premature failures of card clothing can be traced back under some circumstances to improper winding. When the card clothing was wound by the company&#39;s own specialists, problems seldom arose. Occasionally though, the operators of the carding plants have their own winding equipment, so that the manufacturer of the card clothing has nothing to do with the winding process. Incorrect insertion of the brake device can lead to damage of the clothing edges, leading in turn to premature failure of the carding rolls. This relationship has not been recognised until now, because a production fault in the card clothing has always been assumed, in particular because the plant operators have always maintained that they carried out the winding process correctly.  
       [0007] In order to rectify this situation a brake device with at least one pressing and one idling braking roller and a brake-force device have been made available. The braking force is no longer generated by sliding friction directly on the card clothing, but instead through braking using an intermediate braking roller so that due to equal speeds on the pressing circumference of the braking roller and on the card clothing which it engages stiction conditions prevail. How and at which point the indirect braking occurs via the brake-force device is immaterial, provided, where possible, no sliding friction between the braking roller and the card clothing arises. Consequently, the card clothing is always wound without damage and with the required pretension onto a roll main body. Such stiction conditions between the card clothing and the braking roller can also be more easily controlled and can be more easily determined than sliding friction conditions, which is why improved drive and control of the winding conditions can take place.  
       [0008] According to one embodiment, a pair of braking rollers can be provided through which the card clothing can be passed and which together provide a braking effect. The braking effect can also be very significantly influenced by the selection of the material for the braking rollers. Furthermore, there is also the possibility that only one braking roller is braked by the brake-force device, whereas the other braking roller acts as an idling counter-support. By passing through a braking-roller gap specific guiding of the card clothing is implemented. The pressing force can also be set or be open or closed-loop controlled.  
       [0009] In this respect it is also favorable if according to a variant at least one braking roller is provided as guide roller with a profile, whereby the profile is matched to a section of the outer contour of the card clothing to be wound. Due to the application of wire-shaped clothing, the cross-section of the card clothing remains substantially constant over the complete wire length which is why an appropriate profile of the braking roller is suitable for positionally accurate guidance.  
       [0010] Furthermore, for the winding of card clothing with a narrow tooth region and a wide base region at least one braking roller can exhibit a circumferential groove in which the base region of the card clothing largely accurately fits. Consequently, guidance does not just occur in the horizontal direction, but also in the vertical direction, because the base region cannot disengage from the circumferential groove (ring groove). The widened base region of the card clothing can exhibit all the current cross-sectional shapes. Apart from the often used rectangular-shaped cross-section, there are also base cross-sections which exhibit a type of tongue and groove profile so that base regions arranged adjacently can be chained together. For example, a triangular-shaped groove may extend below the tooth region and on the other side of the base region a triangular-shaped tongue. The tongue and groove then engage largely with an exact fit with adjacent windings of the clothing.  
       [0011] Preferably, the braking roller can exhibit a shaft supported in bearings onto which the brake-force device acts. The shaft is then normally permanently joined to the braking roller. The brake-force device can in turn achieve a brake-force effect via sliding friction. The sliding friction occurs remotely from the card clothing so that it has no effect on it and the already mentioned indirect braking occurs. If effects of wear appear between the shaft and the brake-force device, the brake-force device can be designed for easy replacement.  
       [0012] Furthermore, the brake-force device can include brake blocks which act on the shaft. Here, all the current designs of brake block can be used which can act directly or indirectly on the shaft.  
       [0013] In order to be able to control the braking effect better, an adjustment unit for adjusting the braking effect can be included.  
       [0014] Furthermore, it is also possible that the brake device includes an open and/or a closed-loop control unit through which the braking effect can be automatically matched to the winding pretension. This ensures that the complete card clothing is wound with a specified pretension. Generally, this is the same over the whole winding process. However, different controls over the winding process are possible.  
       [0015] In this respect it is also of advantage if, according to a variant, the roll drive unit is integrated into the open and/or closed-loop control circuit of the open and/or closed-loop control unit and the roll drive unit can be open or closed-loop controlled for automatic matching to the specified winding pretension. The roll drive and the braking effect and also the pretension they produce can be matched exactly to one another so that the desired pretension and therefore the optimum winding of the card clothing onto the roll main body always occur.  
       [0016] According to one variant, there is also the possibility that the brake device includes a braking motor or an eddy current brake or a torque brake which then applies the braking effect without sliding friction being present between the braking rollers and the card clothing. With one variant a brake-force sensor is included in the brake device. The sensor can, for example, continuously record and document the braking force electronically. Consequently, quality control for the winding of the card clothing is provided.  
       [0017] The brake device can include a recording unit for recording the braking force and/or the winding speed. Consequently, a number of parameters can be recorded and monitored in parallel with one another.  
       [0018] Furthermore, the brake device can also include a speed sensor. This can, for example, also be used for real-time recording in which, for example, the braking force and winding speed are monitored in parallel.  
       [0019] At least two braking rollers can be arranged in series. These then press consecutively onto the card clothing so that an improved dosage of the braking is possible. With the use of pairs of braking rollers on both sides of the card clothing, the braking rollers arranged in series can also be grouped symmetrically, so that a number of pairs of braking rollers can be arranged in series consecutively. However, an offset arrangement is also conceivable.  
       [0020] Another variant provides that a braking band is passed over the braking rollers arranged in series, the braking band being pressed onto an outer side of the card clothing. The braking band runs like a type of conveyor belt around the braking rollers and is pressed by them against the card clothing. This results in a more uniform transfer of the braking force over the complete length of the side of the braking band in contact with the card clothing. The braking band can consist of the most varied materials. Here, recirculating chains with appropriate brake linings can be used so that the braking rollers can be formed as a type of chain wheel. Also here, the paired arrangement for force application on both sides of the card clothing is possible. 
     
    
    
     [0021] In the following an embodiment of the invention is explained in more detail based on a drawing. The following are shown:  
     [0022]FIG. 1 shows a schematic representation of a winding device in a side view and  
     [0023]FIG. 2 shows a schematic representation of a brake device cut along the line II-II in FIG. 1. 
    
    
     [0024] The winding device  1  illustrated in FIG. 1 includes primarily a holding station  2  for a feed spool  3  on which a sawtooth-shaped card clothing  4  is wound flat, a brake device  5  and a roll  6 . The roll  6  is driven by a motor  7  and a transmission device  8  in the clockwise direction. The motor  7  has an open and closed-loop control device  9  through which the speed of the roll  6  and the direction of rotation can be controlled. The brake device  5  includes an open and closed-loop control device  10  which ensures a certain braking effect. The open and closed-loop control device  9  and the open and closed-loop control device  10  interact with one another. In another embodiment these can be used as a unit for controlling both the brake device  5  and the motor  7 .  
     [0025] The sawtooth-shaped card clothing  4  is wound off the feed spool  3  arranged on the pedestal  11 , then passed through the brake device  5  and wound onto the outer circumference of the roll  6 . After the winding process, the card clothing  4  then runs in a screw shape on the outer circumference of the roll  6 .  
     [0026] The brake device  5  is illustrated in FIG. 1 just schematically as a box. This is explained in greater detail based on FIG. 2.  
     [0027] In conjunction with the roll  6 , and here in particular via the roll drive motor  7 , the brake device  5  should apply a pretension in the region  12  of the card clothing  4 . This pretension ensures an even and lasting winding of the card clothing  4 .  
     [0028] Based on FIG. 2, it can be seen that in cross-section the card clothing  4  has a narrow upper tooth region  13  and a wide, largely rectangular-shaped base region  14 . As a result, a shoulder  15  arises between the tooth region  13  and the base region  14 . The brake device  5  includes a pair of braking rollers with a left, cylindrical braking roller  16  and a right, largely cylindrical braking roller  18  with a ring groove  17 . The ring groove exhibits a rectangular shape in cross-section and in its width is formed to the height of the base region  14 . Consequently, part of the base region  14  passes largely exactly in the ring groove  17 . The base of the ring groove  17  presses against the right side surface  19  of the card clothing  4 . The left side surface  20  of the card clothing  4  contacts the cylinder jacket surface of the brake roller  16 . The card clothing  4  is then passed through a gap  21  between the two braking rollers  16  and  18 . The upper side wall  22  of the ring groove  17  guides the shoulder  15 , whereas the lower side wall  23  of the ring groove  17  engages the underside  24  of the base region  14 . The card clothing  4  is consequently guided both in the horizontal and in the vertical direction between the braking rollers  16  and  18 .  
     [0029] The braking roller  16  is arranged coaxially on a shaft  25  and the braking roller  18  is fitted coaxially on a shaft  26 . Both shafts are each rotationally supported such that the braking rollers  16  and  18  are each arranged for rotation together with their shafts  25  and  26  about the axes A and B. A brake-force device  27  acts on the shaft  25  and a brake-force device  28  acts on the shaft  26 . Both brake-force devices  27  and  28  are only schematically illustrated and should be regarded as an example for a braking effect used for the indirect braking of the card clothing  4 . The brake-force devices  27  and  28  described as an example each include brake blocks  30  pressing on the outer jackets of the shafts  25  and  26  through adjustable springs  29 . Both the shafts  25  and  26  and the brake-force devices  27  and  28  can be designed to be replaceable, e.g. in case of wear.  
     [0030] The braking force applied in each case by the brake-force devices  27  and  28  can be open or closed-loop controlled via the open and closed loop control device  10 , so that a specific braking effect can be achieved. It is important with this design of the brake-force device  5  that, where possible, no sliding friction is present between the card clothing  4  and the braking rollers  16  and  18 . Due to the same speed on the circumference of the braking rollers  16  and  18  and on the right and left side surfaces  19  and  20  of the card clothing  4 , a stiction effect of the brake device  5  can be said to occur. The brake-force devices  27  and  28  accordingly brake the card clothing  4  indirectly.  
     [0031] A further possible form of the indirect brake is the braking of the braking rollers  16  and  18  via sliding friction on the outer or inner circumference or braking via a braking motor, an electromagnetic brake or similar.  
     [0032] Also, the surface of the braking rollers  16  and  18  can exhibit a defined roughness through to knurling in order to prevent the card clothing  4  from sliding through due to the pretension. Also it is very simple to provide the brake device  5  with sensors which, for example, count the meters passing through, record the speed during winding and finally, also for a braking motor, continuously record the braking force and, where necessary, pass this information to the closed-loop control circuit. There is also the possibility of logging the winding process and processing this data (e.g. storing, printing out, etc.). In particular the winding tension or any distortion present can be recorded. The devices needed for this can be provided as an extra expansion or as accessories or as an integral unit.  
     [0033] Through all these different variants of the brake device  5  no relative speed between the card clothing  4  and the outer circumference of the braking rollers  16  and  18  should occur so that a completely specific pretension can be applied. Also, for the closed-loop control circuit for matching the brake device  5  to the drive through the motor  7  of the roll  6  there are various embodiments with which sensors certainly play an important role.  
     [0034] The described winding device  1  is particularly suitable for a winding procedure using full steel clothing. Apart from the rectangular cross-sectional shape of the base region described in this embodiment the most varied shapes can be used which also lead to chaining of the adjacent windings of the card clothing, in particular the tongue and groove arrangement (e.g. triangular).  
     [0035] Through the use of braking motors or eddy current brakes or torque brakes, the closed-loop control circuit can be simplified. For example, a brake force sensor can continuously record the braking force and document it for quality inspection. Along with the braking force, the winding speed can also be acquired in parallel using a second sensor. As a result, real-time recording is also possible.  
     [0036] With another embodiment, which is not illustrated, a number of braking rollers can also be arranged on one side of the card clothing in series consecutively. A number of braking rollers then press onto one side of the card clothing. A row of braking rollers can in turn be assigned to this row of braking rollers on the opposite side of the card clothing. These can be arranged at the same height so that pairs of braking rollers are arranged in series consecutively. An offset arrangement is also possible. A recirculating braking band can be passed over these consecutively arranged braking rollers, so that this braking band is pressed against the card clothing. The implementation of the braking band as a chain with appropriate pressure lining is also possible, so that the braking rollers would then be designed as a type of chain wheel.