Patent Publication Number: US-8973802-B2

Title: Wire-processing machine with length-compensating unit

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to European Patent Application No. 10170192.8, filed Jul. 20, 2010, which is incorporated herein by reference. 
     FIELD 
     The disclosure relates to a wire-processing machine. 
     BACKGROUND 
     Typically in a wire-processing machine  1 , as shown in  FIGS. 1A and 1B  by reference to an example, the wire K is transported by means of a wire-drive  3  (e.g. in the form of a belt-drive) from a reel, or from a wire-drum, to a cutting unit  4  of the wire-processing machine  1 . 
     The wire-processing machine  1  can approach the individual processing modules  5 ,  6  by moving two swivel-units  7 ,  8 . Such wire-processing machines  1  have the wire-drive  3  that is arranged before the first swivel-unit  7  and ideally a wire-gripper that is arranged at the end of the swivel-units  7 ,  8 . So that the wire K cannot deviate during transport, and so that, therefore, when cutting the wire K, an exact length results, the wire K is guided between the wire-drive  3  and a gripper  7 . 1  of a first swivel-unit  7  in a flexible guide-tube  11 . As can be seen in  FIG. 1B , usually arranged on the first swivel-unit  7  after the gripper  7 . 1  is a guide-tube  10  which is exactly adapted to the wire diameter. This guide-tube  10  allows the wire-overhang, in other words the length of the free, unguided wire-end, to be kept as short as possible and the droop of the wire-end to be minimized. 
     Furthermore, such a wire-processing machine  1  typically contains an exit-side conveyor-belt  12  and, for example, a wire-deposit as shown in  FIG. 1A . 
     Before cutting, or any other processing step, the wire K is grasped by the gripper  7 . 1  of the swivel-unit  7 . Then, in the cutting unit  4 , the leading wire-end is separated and, after cutting-in, stripped of insulation by means of a backwards-directed lengthwise movement of the gripper  7 . 1 , to be then brought, for example with the swivel-unit  7 , to a processing unit  5 . The leading wire-end can then be, for example, fitted with a seal and a crimp-contact. When fitting of the leading wire-end is complete, the gripper  7 . 1  is opened and the swivel-unit  7  travels back to the blade unit  4 . 
     By the wire-drive  3 , the wire K is now moved at high speed on the conveyor-belt  12  through the cutting unit  4 . This operation is known as “shooting-in” of the wire K. Shooting-in takes place in such manner that the desired wire-length of the wire K is attained, the conveyor belt  12  ensuring that the wire K always remains stretched. 
     After transport of the desired wire-length, a gripper of the swivel-unit  8  grasps the wire K. The wire K is then separated, and the trailing wire-end stripped of insulation. Simultaneously, on the swivel-unit  7 , the same procedure begins again with the next piece of wire. The trailing wire-end is now brought by the swivel-unit  8  to the processing module  6 . After fining of the trailing wire-end, the wire K is, for example, laid in a tray, which serves as wire-deposit  13 . 
     Shown in  FIG. 1B  is the situation according to the prior art during shooting-in of the wire K. The wire guide-tube  11  is stretched, the wire-gripper  7 . 1  is opened, and the guide-sleeve  10  is positioned in such manner that it cannot collide with the wire-stripping blades  14  when the cutting unit  4  closes. This situation results in the required total length of the guide-pipe  11 , A guide-pipe  11  with the correspondingly defined total length is fastened to two fastening points  11 . 1 ,  11 . 2  which are separated by a distance. 
     Known from patent application EP 1548903 A1 is a corresponding wire-processing machine with an exchangeable guide-tube and a flexible guide-pipe. 
     Apparatuses are known, see for example U.S. 2001/025870 A1, that contain wire-drives and nozzle arrangements through which wires can be pushed. The apparatus according to U.S. 2001/025870 contains no wire-gripper. The nozzle arrangement has a so-called intermediate nozzle, which contains a stationary and a movable nozzle. The movable nozzle is movable in axial direction by a drive-bar of a cylinder mechanism. The movable nozzle can thereby be transposed from a guiding position into a non-guiding position. In the non-guiding position, this movable nozzle is not connected with another nozzle of the nozzle arrangement. The apparatus according to U.S. 2001/025870 contains no wire-pipe and no wire-gripper. The nozzle arrangement with movable nozzle serves exclusively to bridge a gap between the vertically movable wire-guide of the wire-changer and the wire arrangement while the wire is being changed. During insulation-stripping, or in the swiveled-out state, the nozzle arrangement is inactive. 
     An apparatus according to U.S. Pat. No. 4,663,822 has a telescopic tube to bring wires safely through opened blades of a separating and insulation-stripping unit during advancement. The telescopic tube can be shortened or lengthened, it is, however, not connected with a guide-pipe. A swivel-unit is completely absent. 
     Known from patent application FR 2691016 A1 is a wire-handling machine which contains a guide-pipe which can be moved by a swivel-unit. While the wire is being inserted, air is applied to the guide-pipe from the side. The wire-handling machine has no length-compensating unit, 
     At least some prior art devices have the disadvantage that, for example, when shooting-in the wire, contact occurs between the leading wire-end and the blades of the cutting unit. Depending on the processing step, the wire-overhang at the wire-end is either too short or too long. 
     SUMMARY 
     In at least some embodiments disclosed herein, the wire apparatus, or a wire-processing apparatus respectively, is equipped with a corresponding length-compensating unit, which offers an array of advantages. The length-compensating unit can provide passively or actively, depending on the embodiment, a different effective length of the guide-pipe. 
     This type of wire-guide can also be used in other machine concepts, for example in wire-processing apparatuses that have a transfer system instead of the second swivel-unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is explained in more detail by reference to the attached figures. Shown are in: 
         FIG. 1A , a plan view of part of a previously known wire-processing machine; 
         FIG. 1B , a side view of part of the previously known wire-processing machine according to  FIG. 1A ; 
         FIG. 2 , a side view of an embodiment of a wire-feeding apparatus with length-compensating unit; 
         FIG. 3A , a perspective view of an embodiment of a length-compensating unit; 
         FIG. 3B , a cross-sectional view of the length-compensating unit according to  FIG. 3A  in retracted (contracted) state; 
         FIG. 3C , a cross-sectional view of the length-compensating unit according to  FIG. 3A  in extended (expanded) state; 
         FIG. 4 , a side view of a part of a wire-processing apparatus with length-compensating unit; 
         FIG. 5 , a plan view of a part of a corresponding wire-processing apparatus; 
         FIG. 6 , a three-dimensional view of an embodiment of a swivel-arm with gripper, guide-pipe, and guide-tube of a wire-processing apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Certain aspects of a wire-processing apparatus  1  were already described in connection with  FIGS. 1A and 1B . At least some of what was described there can also be applied to one or more of the following embodiments. 
       FIG. 2  shows a wire-feeding apparatus  100  of a wire-processing machine or apparatus  1 . The wire-feeding apparatus  100  contains a wire-advance device  103  which is embodied as belt-drive (not shown in  FIG. 2 ), wherein the wire-advance device  103  feeds a wire K of a swivel-unit  107  with a swivel-arm  107 . 2  with gripper  107 . 1 . Here, the wire-advance device  103  is also designated as wire-drive  103 . The wire-advance device  103  can, for example, be executed similar to the wire-advance device  3  in  FIG. 1A . The wire K is guided in a flexible (wire-)guide-pipe  111 , the advanced wire-length being measurable, for example, by means of an optional encoder (not shown) of the wire-advance device  103 . 
     The flexible (wire-)guide-pipe  111  is fastened on the entry-side to a length-compensating unit  120  as shown in  FIG. 2  and emerges on the exit-side in the area of a gripper  107 . 1  of the swivel-arm  107 . 2 . On the exit-side, the guide-pipe  111  is joined to the swivel-arm  107 . 2 . That is to say, at the one end, the guide-pipe  111  is joined via the length-compensating unit  120  lengthwise-movably with the wire-processing machine or apparatus  1  and, at the other end, monolithically-movably with the swivel-arm  107 . 2 . 
     By means of one or more drives  107 . 3 , the swivel-arm  107 . 2  can be set in a swiveling motion (similar to the swivel movement that is symbolized in  FIG. 1A  with an arrow P 1 ) and/or in a linear motion (similar to the linear movement symbolized in  FIG. 1A  with an arrow P 2 ). Details of the drive(s)  107 . 3  and of the swivel-arm  107 . 2  with gripper  107 . 1  are explained in, for example, patent application EP 03405094.8. Further aspects of the technical overall construction can also be taken from the patent application EP 1548903 A1 mentioned at the outset. 
     In  FIG. 2 , the swivel-arm  107 . 2  is shown in the zero position (Position II in  FIG. 5 ) or in the lengthwise axis of the wire respectively, in which here, for example, a cutting unit  104  that serves as processing station is arranged, which cuts into and insulation-strips a leading wire-end, wherein the wire-end is held by means of the gripper  107 . 1  and of a guide-tube  110  which is arranged on the gripper  107 . 1 . The clear diameter of the guide-tube  110  fits onto the external diameter of the wire K. 
     In at least some embodiments, the wire-feeding apparatus  100  contains a guide-tube  110  as mentioned. The guide-tube  110  contains a passage  110 . 1  (not visible in the figures) which extends in the longitudinal direction, The guide-tube  110  is arranged in the area of an exit-side end  111 . 2  of the guide-pipe  111 , as shown by reference to an example in  FIG. 6 , and the passage  110 . 1  runs coaxial to the guide-pipe  111 . 
     In at least some embodiments, the wire-feed apparatus  100  contains a so-called length-compensator or length-compensating unit  120 , as already mentioned, 
     This length-compensating unit  120  possibly sits on the entry-side end of the (wire-) guide-pipe  111 . That is to say, in this case the length-compensating unit  120  sits at the end that lies opposite the end at which the said optional guide-tube  110  is deployed. The guide-tube  110 , if present, sits on the exit-side end of the (wire-) guide-pipe  111 . 
     In total, the constellation can be so chosen that a wire K can be shot-in from the entry-side E through the passage  127  of the length-compensating unit  120  into the (wire-) guide-pipe  111 . The passage  127  of the length-compensating unit  120  and the (wire-) guide-pipe  111  lie mutually coaxial. The optional guide-tube  110  also runs coaxial. 
     Shown in  FIGS. 3A ,  3 B, and  3 C are details of an exemplary embodiment of the length-compensating unit  120 . 
       FIG. 3A  shows a three-dimensional view of an embodiment of a length-compensating unit  120 . The length-compensating unit  120  preferably contains a (gripping-)holder  121  with a cylindrical holder  122 , sitting within which is a bearing bush  123 . Inside the bearing bush  123  a guide-seal  124  is mounted movably in such manner that the length-compensating unit  120  can adopt at least two states. The first state is shown in  FIG. 3B  and is designated as a retracted or collapsed state. In this state, the guide-seal  124  sits further left than in the extended (expanded) state that is shown in  FIG. 3C . 
     In at least some embodiments, the length-compensating unit  120  additionally contains a (lock-)nut  125  to fasten the entry-side end of the guide-pipe  111  to the guide-seal  124 . 
     For this purpose, the end-piece of the guide-seal  124  can have an external thread, which is designed to match the internal thread of the nut  125 . The nut  125  and the guide-seal  124  can be designed so that, on tightening of the nut  125 , the (wire-)guide-pipe  111  is pushed onto a conical seat of the guide-seal  124  and thereby fastened. 
     As shown in  FIG. 3C , the guide-seal  124  can be mounted in such manner, or the length-compensating unit  120  can be so designed, that it can execute a maximum stroke in the longitudinal direction which results from the distance between the positions X 1  and X 2 . 
     Through movement/displacement of the guide-seal  124  relative to the stationary part (e.g. the part  122 ) of the length-compensating unit  120 , the (wire-)guide-pipe  111  makes a movement in the direction of transportation of the wire K (in  FIGS. 3A ,  3 B,  3 C, to the right). 
     The guide-seal  124  is hence correspondingly mounted in the bearing bush  123  in lengthwise-movable manner. In some embodiments, the former can be pulled back by an internally or externally located (compression-)spring  126 , so as to hold the (wire-) guide-pipe  111  stretched within a certain length-range X 1  to X 2 . 
     The length-compensating unit  120  has an entry-side E, an exit-side A, and a cylindrical passage  127 . The passage  127  extends from the entry-side E to the exit-side A, there being on the exit-side A a transition to the guide-pipe  111 , as mentioned, The length-compensating unit  120  can be designed in such manner that shooting-in of the wire K into the passage  127  takes place through the entry-side E and from there into the (wire-) guide-pipe Ill. The passage  127  can have an internal diameter that is somewhat larger than the external diameter of the wire K. 
     In at least some embodiments, the (wire-)guide-pipe  111  can be fastened to the guide-seal  124  with a lock-nut  125 , as described. The (wire-)guide-pipe  111  can, however, also be fastened with other identically acting means. 
     Besides the embodiments of the length-compensating unit  120  shown in  FIGS. 3A-3C , other variants are also possible. 
     For example, in the length-compensating unit  120 , the (compression-)spring  126  can be replaced by another elastic element, for example a pneumatic or hydraulic cylinder. With such a cylinder, the length-compensating function of the length-compensating unit  120  can be programmably turned on and off. In this case, the length-compensating unit  120  would hence be an active length-compensating unit. A pneumatic or hydraulic cylinder or drive  130  is shown in  FIG. 3   c  acting on the guide-seal  124 . 
     The length-compensating unit  120  can, for example, also be designed as a motor-actuated programmable length-compensator. In this case, the length-compensating function of the length-compensating unit  120  can be addressed or set in controlled manner, i.e. also in this case, the length-compensating unit  120  is active. A motor or actuator  130  is shown in  FIG. 3   c  acting on the guide-seal  124 . 
     The length-compensating unit  120  can also be fitted with a blocking capability (e.g. in the form of engagement points) to enable the length-compensating unit  120  to be temporarily blocked in one or more freely definable positions (depending on the method-step or process-step of the wire-processing). A blocking component  131  is shown in  FIGS. 3A and 3C  for blocking the guide-seal  124  at the position X 2 . 
     These various variants of the length-compensating unit  120  can also be mutually combined. Hence, for example, a passive length-compensating unit  120  according to  FIG. 3A  can be fitted with a blocking capability, or a solution with spring  126  according to  FIG. 3B ,  3 C can be assisted by a motor-actuated programmable length-compensator, which results in an active solution. 
     Through deployment of the wire-feed apparatus  100 , the following method, for example, of guiding a wire K can be realized. For this purpose, for the forward movement of the wire K, the respective wire-feed apparatus  100  contains a wire-drive  103  and a guide-pipe  111  with an entry-opening and an exit-opening, the wire-drive  103  moving the wire K forward and shooting it into the guide-pipe  111 . Before execution of a first processing step of the wire K, an effective length of the guide-pipe  111  is lengthened by the deployment of a length-compensating unit  120 . Before execution of a second processing step of the wire K, the effective length of the guide-pipe  111  is shortened by deployment of the length-compensating unit  120 . As already explained, the lengthening and/or shortening can be effected passively (e.g. purely mechanically by the action of a spring  126 ) or actively. The lengthening and/or shortening takes place through interaction of the subassembly, comprising length-compensating unit  120  and guide-pipe  111 , with the swivel-arm  107 . 2  or swivel-unit  107  respectively. 
     In at least some cases, when lengthening and/or when shortening, a movably borne guide-seal  124  of the length-compensating unit  120  is moved. 
     Optionally, further guide-tubes  110  with different clear diameters can be stored in a magazine (not shown in  FIG. 2 ) of the apparatus  100 . In this case, the guide-tube  110  can be exchanged manually or by machine. 
     Depending on the embodiment and the foreseen purpose, the length-compensating unit  120  can be arranged on the entry-side or in the entry-side area of the guide-pipe  111 . It is, however, also possible to arrange the length-compensating unit  120  as intermediate piece of the guide-pipe  111  or on the exit-side of the guide-pipe  111 . If the length-compensating unit  120  is deployed as intermediate piece of the guide-pipe  111 , the guide-pipe  111  contains two parts or sections, which are interrupted by the length-compensating unit  120 . 
     Through deployment of the length-compensating unit  120 , partial areas of the processing or handling method, or of the guiding of the wire K, can be executed in more controlled manner. 
     With shooting-in of the wire K, the following advantages result. Different from the existing method shown in  FIGS. 1A and 1B , when shooting-in starts, the guide-tube  110  can be situated inside the cutting unit  104 , as shown in  FIG. 1  That is to say, the exit-side end of the guide-tube  110  penetrates far into the intermediate space of the cutting unit  104 . The wire-overhang in this state can be correspondingly shorter, and at least some process steps that are executed by the cutting unit  104  can be executed more precisely. 
     In at least some cases, for example in the case of wires K with small cross-section, the danger of a collision of the bending wire with elements (for example, the blades  114 ) of the cutting unit  104  thereby reduces. 
     To further optimize the chronological sequence of events when processing a wire K, the guide-tube  110  can be moved back already before conclusion of the shooting-in (i.e. here in the direction P 3 ), as shown in  FIG. 4 . In some cases, this backwards movement P 3  of the guide-tube  110  can begin as soon as the wire-point (i.e. the leading wire-end) is situated over the conveyor belt (reference number  12  in  FIG. 1B ) and hence there is no further danger of the wire K colliding with elements (e.g. the blades  114 ) of the blade unit  104 . 
     In all further processing steps that are executed with closed wire-gripper  107 . 1  (i.e. with a wire-gripper  107 . 1  whose gripping jaws  107 . 4  are closed), and in which the guide-tube  110  moves backwards in the direction of the wire-drive  103 , the guide-pipe  111  must bend together with the wire K, since otherwise the wire K will be compressed by the wire-drive  103 . This is typically the case during the withdrawal movement of the wire-stripping operation. Wire-stripping takes place through blades  114  (possibly V-shaped wire-stripping blades are deployed) of the cutting unit  104  being presented in the direction of the wire K and penetrating the insulation of the wire K. The wire K, along with the guide-tube  110 , is then moved a short distance to the left, to remove a separated piece of the insulation, a bending of the guide-pipe  111  resulting automatically when the shortest length of the length-compensating unit  120  (e.g. the state shown in  FIG. 3B ) is attained, or when the length-compensating unit  120  in one of the mentioned alternative embodiments becomes blocked. 
     The said backwards movement of the wire K along with the guide-tube  110  is optional but offers advantages that depend on the situation. 
     In some cases, compression of the wire K during the withdrawal movement when insulation-stripping can also be prevented by the wire-drive  103  moving the wire K backwards. However, under certain circumstances, this can be disadvantageous for the accuracy of the length, and can unnecessarily lengthen the processing time. 
     In a further embodiment, a reduction of the wire-overhang takes place on swiveling-back of the wire K from a processing position into the wire-advance position. In the processing position, for example the leading wire-end of the wire K has been processed by a processing station  5 , as shown in  FIG. 1A , or by a processing station  105 , as shown in  FIG. 5 . 
     The principle of reducing the wire-overhang on swiveling-back is shown diagrammatically in  FIG. 5 . In Position  1 , the leading wire-end is situated in the area of a processing station  105 . Here, the wire-end projects further out of the guide-tube  110  (i.e. the wire-overhang is greater) than in Position H. That is to say, through the action of the length-compensating unit  120 , on transition from Position  1  into Position Il the wire K is slightly pulled back. Generally, the maximum stroke that is possible here is determined by the design of the length-compensating unit  120  and the movement of the gripper  107 . 1  or of the swivel-arm  107 . 2 . 
     In another embodiment, during the said swiveling-back from the processing position to the wire-advance position, the length-compensating unit  120  offers the possibility of passively or actively (depending on the embodiment) reducing the wire-overhang. This can be achieved, for example, by the swivel-unit  107  continuously extending the swivel-arm  107 . 2  while swiveling back. 
     In  FIG. 6  a three-dimensional view of the front part of an exemplary embodiment of a swivel-arm  107 . 2  with gripper  107 . 1 , guide-pipe  111 , and guide-tube  110  is shown. The guide-pipe  111  is fastened with the correspondingly defined total length to a fastening point  111 . 1  on the swivel-arm  107 . 2 , as shown in  FIG. 6 . In the area of the gripper  107 . 1 , the guide-tube  110  is fastened to the swivel-arm  107 . 2 . The swivel-arm  107 . 2  with gripper  107 . 1  and guide-tube  110  serves, for example, as feeding device for feeding wire-ends of the wire K to a processing station  105 . The gripper  107 . 1  is shown with opened gripper-jaws  107 . 4 . To grip the wire K, which is not shown in  FIG. 6 , the gripper  107 . 1  is lowered and the gripper-jaws  107 . 4  are closed. 
     According to at least some embodiments, the length-compensating unit  120  changes the effective length of the guide-pipe  111  uninterruptedly according to the linear and/or swiveling movement of the swivel-unit. 
     In at least some embodiments, the lengthening and/or shortening of the effective length of the guide-pipe  111  results from an interaction between the swivel-arm  107 . 2  and the guide-pipe  111  with the length-compensating unit  120 . A swiveling or linear movement P 1 , P 2  (see, for example,  FIG. 5 ) effects a change in length of the guide-pipe  111  along with the length-compensating unit  120 , the effective length of the guide-pipe  111  changing through deployment of the length-compensating unit  120 . 
     By lengthening and/or shortening the effective length of the guide-pipe  111 , possibly on the exit-side on the guide-pipe  111  the wire K or the wire-end of the wire K can be controlled or positioned better and more accurately. Hence, for example, the wire-overhang can be optimally specified. 
     Some embodiments can also use a swivel-unit  107 , with a swivel-arm  107 . 2  and a wire-gripping apparatus, instead of the gripper  107 . 1 . For this reason, the term “wire-gripping apparatus” is sometimes used, since this term describes not only grippers but also other means that act similarly. 
     When crimping, or particularly when fitting seals, the wire-overhang, given by the respective processing station(s), should normally be greater than the wire-overhang given by the improved shooting-in. It is sometimes advantageous to reduce the wire-overhang during swiveling-back. Oscillation of the free wire-end can thereby be reduced and swiveling can be executed faster. 
     Through deployment of a length-compensating unit  120 , a variable wire-overhang can thereby be actively or passively specified depending on the situation. 
     In general, the length-compensating unit  120  can mean that the wire-overhang can be varied for the individual process steps without it being necessary for the wire K to be capable of being moved backwards or forwards by the wire-drive  103 . 
     This feature can be deployed when shooting-in and/or separating and/or insulation-stripping, the wire-overhang resulting in each case from the distance of the guide-tube  101  from the cutting blade of the cutting unit  104 . 
     In at least some embodiments of the new method, the wire-overhang can be selected smaller, and also suitable for the processes on the processing modules. 
     Having illustrated and described the principles of the disclosed technologies, it will be apparent to those skilled in the art that the disclosed embodiments can be modified in arrangement and detail without departing from such principles. In view of the many possible embodiments to which the principles of the disclosed technologies can be applied, it should be recognized that the illustrated embodiments are only examples of the technologies and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims and their equivalents. We therefore claim as our invention all that comes within the scope and spirit of these claims.