Patent Publication Number: US-2023140386-A1

Title: Vibration-damping apparatus for a winding device of a textile machine which produces cross-wound packages

Description:
The invention relates to a vibration-damping apparatus for a winding device of a textile machine that produces cross-wound packages, the vibration-damping apparatus being provided for reducing the vibrations that occur at the pivotably mounted package cradle during the winding operation of the textile machine. 
     During the winding operation of textile machines that produce cross-wound packages, for example open-end rotor spinning machines or automatic winding machines, there is always the risk of excessively intense vibrations of the package cradles at the workstations as the cross-wound packages are being wound. Especially at the start of a package journey and during the production of relatively hard cross-wound packages, there is often a risk that the amplitude of the cradle vibration will become so large that the winding process is critically impaired, i.e. that cross-wound packages are produced which can barely be unwound later and therefore are unusable. 
     In order to avoid producing such inferior cross-wound packages, in the spinning or winding machines of prior art the pivotably mounted package cradles of the winding devices are generally each equipped with a vibration-damping apparatus. That is, the pivotably mounted package cradle, which has two package cradle arms for freely rotatably holding a cross-wound package, has a damping apparatus, which should ensure that the vibrations of the package cradle, which are nearly unavoidable during the winding operation, are minimised as much as possible. 
     Such damping apparatuses for pivotably mounted package cradles have long been known and are described in various embodiments in the patent literature, in some cases in relatively great detail. 
     For example, vibration-damping apparatuses that have a damping and lifting cylinder are prior art. Such damping and lifting cylinders have a pneumatically operating device for the defined lifting of a cross-wound package held in the package cradle from the package drive roller or supporting roller of the cross-wound package and have a hydraulically operating damping apparatus. The damping apparatus preferably works with oil as the damping medium. That is, the package cradle vibrations occurring during the winding operation are reduced by influencing the flow of the liquid damping medium. 
     A vibration-damping apparatus designed in such a way is described, for example, in the manual “AUTOCONER 238” from Schlafhorst on pages 01.3.9 and 01.3.11. 
     Comparable vibration-damping apparatuses for the winding devices of textile machines that produce cross-wound packages are also disclosed in DE 41 21 780 A1, DE 195 34 333 A1 and DE 100 46 603 A1. That is, these patent applications also describe winding devices in the case of which the damping apparatuses for the package cradle are in the form of hydraulic cylinders. 
     For example, DE 41 21 780 A1 discloses and describes that, in such hydraulic cylinders, the pistons are each equipped with some through-holes, through which damping medium, for example hydraulic oil, located in the cylinder flows in the event of vibrations of the package cradle, leading to damping of the vibrations of the package cradle. 
     The vibration-damping apparatus described in DE 100 46 603 A1 also operates with a similar hydraulic cylinder. However, in this damping apparatus of prior art the damping medium of the hydraulic cylinder is formed by a rheologically variable liquid, i.e. by a liquid the viscosity of which can be varied by means of a magnetic field generator. In these damping cylinders of prior art in the form of hydraulic cylinders, a sealing ring is arranged between the cylinder lower part and the cylinder upper part. 
     Furthermore, such damping cylinders have a piston rod seal, which should prevent damping medium from escaping from the hydraulic cylinder. Although the sealing elements of these damping cylinders of prior art have been steadily improved over time, such hydraulically operating damping cylinders always have the risk that damping medium will escape, not only leading to soiling of the surroundings and often to worsening of the damping behaviour, a worsening which is not immediately noticeable, but also posing a significant fire hazard in conjunction with the fibre dust that is nearly unavoidable in textile companies. 
     Therefore, various attempts to replace such hydraulically operating damping apparatuses with damping apparatuses that do not need any liquid damping medium have already been undertaken in the past. 
     For example, the Swiss patent document CH 374 003 describes a damping apparatus that has an energisable electromagnet, which acts on an armature plate, which in turn is connected by means of a rod to the pivotably mounted package cradle to be damped. That is, in the case of this damping apparatus of prior art, a force component that presses the ferromagnetic armature plate connected to the package cradle onto a stationary abutment is produced by means of an electromagnet which, as is known, contains an energisable coil. The damping behaviour of this known damping apparatus thus results from the mechanical friction between the movably mounted armature plate and the stationary abutment. 
     A comparable but contactlessly operating electromagnetic damping apparatus is also disclosed in DE 100 12 005 B4. This damping apparatus has a movable, electrically conductive component, which is at least indirectly connected to the package cradle and is arranged in such a way that the component contactlessly intersects the magnetic field of a stationary magnet system. The damping behaviour of this damping apparatus of prior art is based on the formation of eddy currents in the electrically conductive component. However, in practice it has been found that both the damping apparatuses according to the patent document CH 374 003 and the damping apparatuses according to DE 100 12 005 B4 have various disadvantages. For example, in the case of the damping apparatuses based on the eddy current principle, the force induced on the conductive component by the magnetic field of the magnet system was not sufficient for achieving satisfactory damping. The damping apparatuses described above were never able to establish themselves in practice. 
     Furthermore, DE 26 06 859 A1, DE 10 2007 047 554 A1 and DE 199 24 390 A1 also disclose winding devices for the workstations of textile machines that produce cross-wound packages, in the case of which winding devices each package cradle pivotably mounted on the machine frame of the textile machine is equipped with a damping apparatus. The damping apparatuses operate as friction dampers, similarly to the damping apparatus disclosed in patent document CH 374 003. 
     For example, in the device according to DE 26 06 859 A1, a movably mounted package cradle is equipped with a braking element, which is mounted so as to be damped and corresponds with a stationary counter-body. That is, the braking element has brake pads, which contact a counter-body arranged so as to be stationary on the machine frame of the textile machine. 
     A device equipped with a friction element, for damping the vibrations occurring at the package cradle during the winding process of a cross-wound package, is also described in DE 10 2007 047 554 A1. In the case of this damping apparatus, a counter-body, which is likewise arranged so as to be stationary on the machine frame of the textile machine, is acted upon by a friction element, which can be acted upon by a pneumatic cylinder. 
     The damping apparatus described in DE 199 24 390 A1 has a guide rod, which is movably fastened to the package cradle and which corresponds with braking elements of a cylinder device, which cylinder device is arranged on the machine frame of the textile machine and is mounted for limited movement. That is, a slidable, pneumatically actuatable piston, inter alia, is mounted in the cylinder device, which piston applies a braking element to the guide rod and thus initiates a friction torque, which leads to vibration-damping of the package cradle in question during the winding operation. 
     As indicated above, the damping apparatuses of prior art have various disadvantages, which means that these damping apparatuses can be improved. 
     Proceeding from the prior art indicated above, the invention addresses the problem of developing a vibration damper for a pivotably mounted package cradle of a winding device of a textile machine that produces cross-wound packages, the vibration damper being unproblematic with respect to the likeliness of soiling, and the vibration damper ensuring that the package cradle is relatively stable with respect to vibration during the winding process. 
     This problem is solved according to the invention in that the vibration damper is in the form of a friction damper which has friction forces of different intensity depending on the working direction, the friction forces effective as the cross-wound package lifts off during the winding operation being greater than the friction forces effective during the return movement of the cross-wound package. 
     The dependent claims relate to advantageous embodiments of the invention. 
     The vibration damper designed according to the invention not only has the advantage that, because of the design as a mechanically operating friction damper, the risk of soiling of the workstation by escaping damping medium is eliminated, but also the advantage that, because of the friction damper&#39;s special design according to the invention, the problem of the constant lifting off of the cross-wound package due to vibration is minimised during the winding process. That is, the friction damper designed according to the invention produces direction-dependent friction forces, the friction forces that become effective in the blocking direction as the cross-wound package lifts off being significantly greater than the friction forces effective during the lowering of the cross-wound package. The compact design of the friction damper also allows the damping apparatus according to the invention to be retrofitted on workstations of textile machines with package cradles that have formerly been equipped with hydraulic damping cylinders. That is, only few minor modifications are required in the region of the workstations of textile machines in order to be able to advantageously install the friction dampers designed according to the invention. 
     In an advantageous embodiment, the friction damper according to the invention has: a braking rod, which is mounted for sliding relative to the damper housing of the vibration damper; a stationary first braking element; and a movably mounted second braking element, which can be placed against the braking rod by means of a support lever. 
     As a result of such a design, the friction damper has a blocking direction and an idle direction. For this purpose, the support lever is arranged at an angle to the braking rod in such a way that the second braking element is automatically pressed against the braking rod more strongly when the cross-wound package attempts to lift off from its associated package drive drum. That is, if the cross-wound package, which lies on the package drive drum and is driven by the package drive drum by means of frictional contact, begins to vibrate during the winding process, for example because of a small out-of-roundness, torques are immediately transferred to the package cradle. The torque that attempts to lift the package cradle and thus also the housing of the vibration damper immediately causes a stronger pressure to be applied to the second braking element, with the result that a strong friction torque is produced. 
     At this time, the vibration damper works in what is referred to as the blocking direction. 
     In another advantageous embodiment, the vibration damper has a spring element, which acts, in frictional contact, on the support lever, the support lever being arranged at angle to the braking rod. The spring element is preferably a compression spring, the compressive force of the spring element being adjustable by means of an adjusting screw. Such a design ensures that the friction force with which the braking elements contact the braking rod in the assembled state can be adjusted in a defined manner. That is, the magnitude of the friction force acting on the braking rod can be influenced by means of the compressive force of the spring element and it can thus be ensured that the support lever reliably becomes effective in the blocking direction as needed. 
     In an advantageous embodiment, one end of the support lever is connected to the second braking element such that limited movement is allowed, while the other end is supported in a guide of the damper housing by means of a guiding and arresting device. The guiding and arresting device is slidably mounted in the preferably circular-arc-shaped guide of the damper housing and can be positioned there in a defined manner. The advantageously arranged guiding and arresting device forms a pivoting and support point for the support lever during operation. This means that, by appropriately positioning the guiding and arresting device in the circular-arc-shaped guide of the damper housing, the angle that the support lever assumes in relation to the braking rod can be set and thus the contact pressure of the second braking element can be influenced, which contact pressure greatly contributes to the friction torque. 
     In another advantageous embodiment, the first braking element and the second braking element are identical components. That is, the first braking element and the second braking element each have two through-bores for fastening and one recess. A brake lining can be exchangeably installed in each recess. 
     The use of identical braking elements has the advantage that the number of differently designed components can be minimised and thus the production costs of the friction damper designed according to the invention can be kept relatively low. Equipping the braking elements with exchangeable brake linings also allows orderly, economical operation of the friction damper according to the invention. If the operating personnel determine, for example, that a cross-wound package is not running completely smoothly during the winding process, this can be due to somewhat weakened damping behaviour of a friction damper according to the invention. In such a case, this can be easily dealt with by simply exchanging the brake linings, thus restoring the optimal friction conditions of the damping cylinder. 
    
    
     
       The invention is explained in greater detail below on the basis of an embodiment example shown in the drawings. 
       In the drawings: 
         FIG.  1    shows a side view of a workstation of a textile machine that produces cross-wound packages, in the embodiment example of an automatic winding machine, comprising a winding device, the package cradle of which is equipped with a friction damper designed according to the invention, 
         FIG.  2    shows, schematically and at a somewhat larger scale, a winding device of a workstation of a textile machine that produces cross-wound packages, which winding device is equipped with a friction damper designed according to the invention, 
         FIG.  3    shows a sectional view of a friction damper designed according to the invention, and 
         FIG.  4    shows a braking element of a friction damper designed according to the invention. 
     
    
    
       FIG.  1    shows a schematic side view of a workstation  2  of a textile machine that produces cross-wound packages, in the embodiment example of an automatic winding machine  1 . As is known and therefore not explained in greater detail, spinning cops  3 , which were produced on ring spinning machines upstream in the production process and have only relatively little yarn material, are rewound to form large-volume cross-wound packages  5  at the workstations  2  of such textile machines  1 . 
     Such automatic winding machines  1  often have a cop and tube transport system  6 , in which transport plates  11  circulate, on which transport plates  11  vertically oriented spinning cops  3  or empty tubes are arranged. Of this cop and tube transport system  6 , only the cop supply line  24 , the reversibly drivable storage line  25 , one of the cross-transport lines  26  leading to the winding units  2 , and the tube return line  27  are shown in  FIG.  1   . 
     Finished cross-wound packages  5  are typically transferred by means of an automatically operating service unit (not shown), preferably a package doffer, to a machine-long cross-wound package transport device  7  and are transported by the package transport device  7  to a package loading station or the like arranged at a machine end. 
     The numerous, identical workstations  2  of such textile machines  1  each have various devices necessary for orderly operation of such a textile machine. The workstations  2  each have, for example, a winding device  4 , which has: a package cradle  8 ; a package drive roller  9 ; and a thread traversing device  10  for the traversing of the thread  16  running onto the take-up package. The package cradle  8  is mounted for limited movement about a pivot axis  12 , which runs parallel to the axis of rotation of a cross-wound package  5 . That is, during the winding operation the surface of the cross-wound package  5  rotatably held in the package cradle  8  lies on the package drive roller  9  and said cross-wound package  5  is driven by the package drive roller  9  by means of friction. Furthermore, a damping apparatus  18  is connected to the package cradle  8  in order to reduce the vibrations that occur as the cross-wound package  5  rolls during the winding process, which damping apparatus  18  has a friction damper  20  designed according to the invention, which friction damper  20 , as explained in greater detail below on the basis of  FIG.  3   , produces different friction forces depending on direction. 
     As indicated in  FIG.  1   , the package drive roller  9  is individual-motor-driven by means of an electric motor  15 , which is connected to a workstation computer  28  by means of a control line. The drive  14  of the thread traversing device  10 , which thread traversing device  10  preferably has a finger thread guide  13  which, during the winding operation, causes the thread  16  running onto the take-up package to traverse, is likewise connected to the workstation computer  28  by means of a control line, the workstation computer  28  being connected in turn to the central control unit  30  of the automatic winding machine  1  by means of a bus system  29 . 
     The workstations  2  of such automatic winding machines  1  generally also each have a thread joining device  21 , such as a pneumatic splicer, a gripper tube  22  for handling the lower thread, and a suction nozzle  17 , by means of which the upper thread that has run onto the cross-wound package  5  after a winding interruption can be received and inserted into the thread joining device  21 . 
       FIG.  2    shows, schematically and at a somewhat larger scale, a winding device  4  of a workstation  2  of a textile machine  1  that produces cross-wound packages, the winding device  4  having a vibration-damping apparatus  18  designed according to the invention. As indicated, the vibration-damping apparatus  18  has a friction damper  20 , the damper housing  31  of which is connected to the package cradle  8  by means of a first mounting rod  19  and therefore can move with the package cradle  8 . 
     As can be seen, additionally the braking rod  32  of the friction damper  18  is connected to a stationary mounting point  33  of the workstation  2  by means of a second mounting rod  23 . 
     The friction damper  20  of the vibration-damping apparatus  18  as shown in a sectional view and in detail in  FIG.  3   , said friction damper  20  being designed according to the invention, has a damper housing  31 , which is provided with a connecting screw thread  34  at the top. A first mounting rod  19  can be fastened in said connecting screw thread  34 , by means of which first mounting rod  19  the damper housing  31  is connected to the package cradle  8  in the assembled state. A braking rod  32  is arranged within the damping housing  31  and is connected to a stationary mounting point  33  by means of a second mounting rod  23 . The damper housing  31  is mounted for sliding relative to the braking rod  32 . 
     As can also be seen, two identical braking elements  39 ,  41  are in frictional contact with the braking rod  32 . The first braking element  39  is stationarily fastened in the damping housing  31 , for example by means of threaded bolts  40 , while the second braking element  41  is movably mounted in the damper housing  31 . That is, the damping housing  31  has a circular-arc-shaped guide  35 , in which a guiding and arresting device  36  is slidably arranged in such a way that the guiding and arresting device  36  can be positioned in a functionally correct manner if necessary. The guiding and arresting device  36  forms a pivoting and support point  37  for a support lever  38 . The support lever  38  is, for its part, arranged at an angle to the braking rod  32  and is also connected to the second braking element  41  such that limited movement is allowed. As is shown, the support lever  38  is also acted upon by a spring element, preferably a compression spring  42 , the effective compressive force of which can be set by means of an adjustment screw  43 . 
       FIG.  4    shows one of the identical braking elements  39 ,  41 . 
     The braking elements  39 ,  41  each have two through-bores  44  for fastening the braking elements as required and a recess  45  for securely receiving an exchangeable brake lining  46 . That is, the first braking element  39  can be stationarily fastened in the damper housing  31  by means of threaded bolts  40 , which penetrate the through-bores  44 . An exchangeable brake lining  46  can be installed in each of the recesses  45 , i.e. a braking lining  46  that can be easily exchanged if necessary. 
     Function of a Friction Damper Designed According to the Invention: 
     During the winding operation, the package cradle  8  is constantly caused to vibrate by the cross-wound package  5 , which lies on the package drive drum  9  and is driven by the package drive drum  9  by means of frictional contact, i.e. the cross-wound package  5 , which runs in a somewhat unsmooth manner, lifts off somewhat from the package drive drum  9  again and again. 
     These vibrations are transferred by means of the first mounting rod  19  to the damper housing  31  of the friction damper  20 , the braking rod  32  of which friction damper  20  is stationarily connected to a mounting point  33  by means of the second mounting rod  23 . That is, every time the cross-wound package  5  lifts off from its associated package drive drum  9 , a lifting torque is also applied to the damper housing  31 , which lifting torque is opposed by the braking elements  39 ,  41 , which are in frictional contact with the braking rod  32 . 
     In the case of the friction damper  20  designed according to the invention, the lifting off of the cross-wound package  5  has the result that the damper housing  31  of the friction damper  20  designed according to the invention is acted upon in such a way that, as indicated by the arrow  48 , a torque is applied to the support lever  38 , which is arranged at an angle, which torque exerts an additional torque on the braking element  41 , and consequently the braking force of the braking elements  39 ,  41 , which is defined by the compression spring  42 , is significantly increased and thus the upward swing of the package cradle  8  is greatly reduced or nearly prevented. 
     During the subsequent downward swing of the package cradle  8 , which is opposite to the so-called blocking direction of the friction damper  20 , the damper housing  31  is also acted upon toward the package drive drum  9 , and consequently, as indicated by the arrow  47 , the angled support lever  38  is acted upon in such a way that no additional torque is exerted on the second braking element  41  any longer. The braking force exerted on the braking rod  32  by the braking elements  39 ,  41  is thereby significantly reduced and the package cradle  8  can swing back into a position in which the cross-wound package  5  properly rolls on the package drive drum  9  again. 
     As is clear and already indicated above, the vibration damper apparatus  18  having the friction damper  20  designed according to the invention is very compact and therefore can also be retrofitted on textile machines that have already been delivered, i.e. on textile machines that were previously equipped with damping cylinders, which are often somewhat problematic because of their hydraulic damping medium. Because of their compact design, the use of the friction dampers  20  according to the invention does not result in any obstruction of possible service units. 
     
       
         
           
               
             
               
                   
               
               
                 List of reference signs 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1 
                 Automatic winding machine 
               
               
                 2 
                 Workstation 
               
               
                 3 
                 Spinning cop 
               
               
                 4 
                 Winding device 
               
               
                 5 
                 Cross-wound package 
               
               
                 6 
                 Cop and tube transport device 
               
               
                 7 
                 Cross-wound package transport device 
               
               
                 8 
                 Package cradle 
               
               
                 9 
                 Package drive drum 
               
               
                 10 
                 Thread traversing device 
               
               
                 11 
                 Transport plate 
               
               
                 12 
                 Pivot axis 
               
               
                 13 
                 Finger thread guide 
               
               
                 14 
                 Drive 
               
               
                 15 
                 Electric motor 
               
               
                 16 
                 Thread 
               
               
                 17 
                 Suction nozzle 
               
               
                 18 
                 Damping apparatus 
               
               
                 19 
                 First mounting rod 
               
               
                 20 
                 Friction damper 
               
               
                 21 
                 Thread joining device 
               
               
                 22 
                 Gripper tube 
               
               
                 23 
                 Second mounting rod 
               
               
                 24 
                 Cop supply line 
               
               
                 25 
                 Storage line 
               
               
                 26 
                 Cross-transport line 
               
               
                 27 
                 Tube return line 
               
               
                 28 
                 Workstation computer 
               
               
                 29 
                 Bus system 
               
               
                 30 
                 Central control unit 
               
               
                 31 
                 Damper housing 
               
               
                 32 
                 Braking rod 
               
               
                 33 
                 Stationary mounting point 
               
               
                 34 
                 Connecting screw thread 
               
               
                 35 
                 Circular-arc-shaped guide 
               
               
                 36 
                 Guiding and arresting device 
               
               
                 37 
                 Pivoting and support point 
               
               
                 38 
                 Support lever 
               
               
                 39 
                 First braking element 
               
               
                 40 
                 Threaded bolt 
               
               
                 41 
                 Second braking element 
               
               
                 42 
                 Compression spring 
               
               
                 43 
                 Adjustment screw 
               
               
                 44 
                 Through-bore 
               
               
                 45 
                 Recess 
               
               
                 46 
                 Brake lining 
               
               
                 47 
                 Arrow 
               
               
                 48 
                 Arrow