Patent Publication Number: US-6662987-B2

Title: Cable processing equipment with cable changer

Description:
The invention relates to cable processing equipment with a cable changer for holding several cables, wherein the cable to be processed is selectable from the cables of the cable changer and can be fed to the processing unit. 
     BACKGROUND OF THE INVENTION 
     There has become known from application specification EP 0 915 538 A2 a cable processing machine with a cable straightening station, a transport station, a cable retracting station and a cable changer. The cable straightening station, the transport station and the cable retracting station are arranged in succession in the cable transport direction. Cables deviating from a straight line or from the cable longitudinal axis, for example with curves, bends, kinks or the like, are straightened by means of the cable straightening station, so that the cables after running through the straightening stations no longer have any deviations perpendicular to the longitudinal axis. The transport station draws the cable through the cable straightening station and pushes the straightened cable to the cable retracting station and further to a cable nozzle at the outlet side. The cable changer serves as a cable feed device and consists of a frame displaceable in the vertical direction. The horizontally guided cables are held in a vertical plane at a specific spacing one above the other and are guided in tubularly constructed spring strips forming guide paths. For changing a cable the frame is moved up and down until the desired cable lies along the processing axis. The cable retracting station, consisting of at least one clamping device and a curve forming device, is activated beforehand, wherein the free end of the cable is drawn back into the cable nozzle. With the deactivation of the cable retracting station, the cable is pushed out of the cable nozzle by a specific overhang. 
     A disadvantage of the known equipment is that, with the tubularly constructed spring strips forming the guide paths, a specific spacing of the cables held one above the other is preset. Only a specific number of cables can be held per meter of frame height. In the case of a larger number of cables to be held, the frame of the cable changer is correspondingly awkward. Moreover, the overhang of the cable has a disadvantageous effect on the centering of the cable after opening of the straightening apparatus. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present invention meets the object of avoiding the disadvantages of the known equipment and of providing cable processing equipment with a cable changer by means of which a cable change can be undertaken free of disturbance. In accordance with the invention a cable processing equipment has a cable changer, a cable transport device to select a cable to be processed, and a clamping device for each cable. The clamping device may comprise a clamping/retracting unit at the inlet side of the cable changer and a clamping unit at the outlet side. The clamping/retracting unit may be formed with the combination of a retraction cylinder and a clamping cylinder actuable against a spring force. 
     The advantages achieved by the invention are essentially to be seen in that the cables can be arranged more densely one above the other in the cable changer and thus the number of cables per meter of frame height can be substantially increased. In the case of a frame constructed to be less high, less mass has to be moved, which in turn makes possible shorter times in cable changing. 
     Moreover, the pick-up region of the rollers of the straightening unit can be reduced. The valley depth of the rollers is smaller, which in turn has a favorable effect on the roller spacing. Cable jams, caused by loose cable or cable loops which are pushed against the cable guide following in cable transport direction, do not arise in the region of the cable transport unit. 
     In addition, it is advantageous that the free cable ends after a cable change do not have to be cut again, because the free cable ends are firmly held. The free cable ends are also precisely positioned after a vertical movement of the cable changer for the take-over for further processing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is explained in more detail by reference to the accompanying figures, wherein: 
     FIG. 1 shows a cable processing equipment of the invention with a cable changer; 
     FIG. 2 shows the cable changer with a loose cable; 
     FIG. 3 shows a straightening path for the cable formed from straightening rollers; 
     FIG. 4 shows a straightening process in the straightening path; 
     FIG. 5 shows details of a clamping unit at the outlet side of the equipment; 
     FIG. 6 shows details of a clamping/retracting unit at the inlet side of the equipment; 
     FIG. 7 shows the clamping/retracting unit in the position for cable transport; and 
     FIG. 8 shows the clamping/retracting unit in the position for cable retraction. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows cable processing equipment  1  with a cable changer  2 . The cable changer  2  stands vertically relative to a base plate  3 , at which a straightening unit  4  and a cable transport unit  5  are arranged. A cable cutting device at the outlet side is not illustrated. The cable changer  2  is movable upwardly and downwardly in the directions shown by an arrow P 1  and consists of a frame  2 . 1  with horizontal frame members  2 . 11  and vertical frame members  2 . 12 . A drive for the upward/downward movement of the frame  2 . 1  is not illustrated. Cable guides  6  are arranged at the vertical frame members  2 . 12 , wherein further cable guides which are at the inlet side with respect to the cable transport direction P 2  are provided with clamping/retracting units  7 , and cable guides at the outlet side are provided with clamping units  8 . The cable guides are, for example, installable in blocks or sets of six upon the vertical frame members  2 . 12  and serve for holding, guiding, clamping and retracting the individual cables denoted by  9 . The cables  9  fed at the inlet side are disposed, for example, on spools or in drums. The clamping/retracting units  7  at the inlet side are switchable by means of a first actuating device  10 , for example a pneumatic cylinder, arranged at the base plate  3 . The clamping units  8  at the outlet side are switchable by means of a second actuating device  11 , for example a pneumatic cylinder, arranged at the base plate  3 . The construction and mode of function of the clamping/retracting units  7  and the clamping units  8  are explained further below. 
     Actuating devices  10 ,  11 , clamping/retracting unit  7  and clamping unit  8  form a clamping device for clamping a cable  9  in the cable changer  2 , at which time the cable is not transported in cable transport direction P 2 . 
     The cables  9  arranged one above the other in the cable changer  2  can have different cross-sections, colors, insulations, conduction properties, etc. According to the respective cable to be processed the frame  2 . 1  is moved up or down until the individual desired cable  9  lies at the height of the straightening unit  4  and the cable transport unit  5 . 
     Before further processing, the selected cable  9  runs through a straightening path through the straightening unit  4 . A Cable  9  deviating from the cable longitudinal axis, for example with curves, bends, kinks or the like, is straightened by means of the straightening unit  4 , wherein a unit of straightening rollers  15  is provided for each side of the particular cable  9  to be processed. Each roller unit is movable in the directions shown by arrow P 3 . During the straightening process the straightening path is closed, wherein the straightening rollers  15  form the straightening path. During the upward/downward movement of the cable changer  2  the straightening path is open, wherein the straightening units are relieved or retracted. 
     The individual cable  9  intended for straightening is moved in the cable transport direction P 2  by a respective portion of cable transport unit  5  provided at each side of the cable  9 . Each portion of cable transport unit  5  is movable in the direction shown by an arrow P 4 . During the transport process the transport path is closed, wherein the transport path is formed by means of belts on each of the portions of the cable transport unit driven by a belt drive  12 . During the upward/downward movement of the cable changer  2  the transport path is open, wherein the transport units are relieved or retracted. 
     FIG. 2 shows the cable changer  2  with a loose cable  9 ′. Thin cables  9 , in particular, after the opening of the straightening path or the transport path may have a sag  13  in the straightening path region or in the transport path region. Moreover, the cable  9 ′ has in the straightening path region a slight wave shape  14  departing from the straightening path. Cables  9  with a sag  13  and/or waves  14  makes closing of the straightening path or the transport path difficult or impossible, particularly in the case of cables  9  arranged closely one above the other. 
     FIG. 3 shows a straightening path formed from straightening rollers  15 . The straightening rollers  15  of the respective portions of straightening unit  4  arranged on each side of the cable  9 ′ constrain the cable  9 ′ into a wave-shaped course through the straightening path. As is evident from FIG. 4, the straightening rollers  15  are so arranged that the cable  9 ′ is strongly deflected at the inlet side and decreasingly deflected in the cable transport direction P 2 . The thinner the cable  9 ′ to be straightened, the more straightening rollers  15  are necessary. 
     FIG. 5 shows details of the clamping unit  8  at the outlet side for fixing the cable  9  ahead of a cable cutting unit, which is not illustrated. The clamping unit  8  consists of a housing, which is not illustrated, for guiding the cable  9  and a clamping element  16 , which is arranged in the housing, for fixing the cable  9 , wherein the clamping element  16  can be activated by means of the second actuating device  11 . Construction and function of the clamping element  16  correspond to that of the clamping element of the clamping/retracting unit  7  which is explained in FIGS. 6-8. A clamping unit  8  and a clamping/retracting unit  7  is provided for each cable  9 . 
     FIGS. 6 to  8  show details of the clamping/retracting unit  7  at the inlet side for the fixing and retraction of the cable  9 , wherein FIG. 7 illustrates the clamping/retracting unit  7  during cable transport and FIG. 8 illustrates the clamping/retracting unit  7  during cable retraction. 
     The clamping/retracting unit  7  consists of a housing  17  for guiding the cable  9  and a retracting element  18 , which is arranged in the housing for the cable retraction, and a clamping element  19 , which is arranged in the housing  17 , for the fixing of the cable  9 . The cable  9  is guided in a cable channel of the housing  17  and runs through the clamping element  19  and the retracting element  18 . 
     The clamping element  19  is constructed as follows: a setting screw  22 , which acts on a compression spring  23  arranged in a bore  21  of the housing  17 , is arranged in the bore  21 . The compression spring  23  acts on a displaceable cylinder  25  having a transverse projecting abutment  26  and a transverse bore  25 . 1  through which the cable  9  passes. When the abutment is placed in contact with the housing  17  as the cylinder is driven by first actuating device  10 , and overcomes the force of compression spring  23 , as shown in FIG. 7, the cable  9  runs freely through the bore  25 . 1  of the cylinder  25  which is aligned with the cable channel  20  in the housing  17 . When the activating device  10  releases the cylinder  25 , as shown in FIG. 8, the cylinder is driven to the left in the Figure by compression spring  23 , and the cable  9  is pressed against the wall of cable channel  20  and firmly clamped. The clamping force is adjustable by means of the setting screw  22 . 
     The retracting element  18  is constructed as follows: A setting screw  28 , which acts on a compression spring  29  arranged in a bore  27  of the housing  17 , is arranged in the bore  27 . The compression spring  29  acts on a spaced hemispherical head  31  of a cylinder  32  having a projecting transverse abutment  33 . When the abutment is placed in contact with the housing  17  by actuating device  10 , as shown in FIG. 7, the cable  9  runs freely past the hemispherical head  31  of the cylinder  32 . When the actuating device releases the cylinder  32 , as shown in FIG. 8, the hemispherical head  31  is driven to the left by compression spring  29 , engaging the cable  9  and causing a cable loop  34  to be formed in the housing  17 . A deflector  35 , for example a pin, arranged in the housing  17  prevents damage to the cable and facilitates formation of the loop. Due to the cable multiple length in the housing  17  the cable  9  is also clamped at the outlet side. The clamping force, dependent on the cable thickness, is adjustable by means of the setting screw  28 . 
     The cylinder  32  further is connected to an arm  36  which is actuable by a ram  37  of the first actuating device  10 , for example a pneumatic cylinder, which also actuates the cylinder  25 . When the ram  37  is extended, the retracting element  18  and the clamping element  19  are in the position shown in FIG. 7, in which cable transport is possible in the cable transport direction P 2 . When the ram  37  is retracted in accordance with FIG. 8 the compression springs  23 ,  29  are determinative, whereby the cable  9  is, as explained above, clamped at the inlet side and retracted at the outlet side of the unit  7 .