Patent Publication Number: US-8113557-B2

Title: Wire gripper jaw drive

Description:
BACKGROUND OF THE INVENTION 
     The present disclosure generally relates to a wire gripping assembly. More specifically, the present disclosure relates to a wire gripping assembly that includes a pair of pivotable lever arms that move between a gripping position and a release position upon the linear movement of a rack member. 
     Presently, wire gripping assemblies are known and widely used in the processing of wire, including the cutting, stripping and crimping of wire sections. 
     Wire gripping assemblies typically include gripping jaws that are movable between a gripping position and a release position. When the gripping jaws are in the gripping position, the wire being processed is securely held by the gripping jaws. When the wire section is moved to the desired location, the gripping jaws are separated to release the section of wire being processed. 
     Currently available wire gripping assemblies include some type of mechanical linkage to move a pair of lever arms between the gripping position and the release position. The mechanical linkage can take many different forms but is typically actuated by some type of air cylinder. In many embodiments, the mechanical linkage creates a significant amount of mass that hinders the movement of the gripper assembly from one location to another. The complex arrangement of the mechanical linkage increases the size of drive member required to move the lever arms and also increases the overall cost and complexity of the wire processing system. 
     SUMMARY OF THE INVENTION 
     The present disclosure relates to a wire gripping assembly for use in a wire processing station that cuts, strips and crimps end connectors onto a section of wire. More specifically, the present disclosure relates to a wire gripping assembly that includes an improved drive mechanism that operates to move a pair of lever arms between a gripping position to a release position. 
     The wire gripping assembly of the present disclosure includes a drive member that causes the movement of a pair of lever arms from a first, gripping position to a second, release position. The drive member is selectively activatable to grip and release sections of wire within a wire processing station. 
     In one embodiment of the present disclosure, the drive member is a drive cylinder having a generally open interior defined by a cylinder wall. The cylinder wall includes a first fluid inlet and a second fluid inlet that each receive a supply pressurized fluid, such as air. The fluid inlets direct the pressurized fluid into the open interior of the drive cylinder. 
     The drive cylinder further includes a drive piston that is positioned within the open interior of the cylinder body. The drive piston engages the outer wall of the cylinder body and is positioned between the first fluid inlet and the second fluid inlet. Pressurized fluid supplied to the first fluid inlet causes the piston to move in a first direction while the supply of pressurized fluid to the second fluid inlet causes the piston to move in a second, opposite direction. 
     The wire gripping assembly includes a rack member mounted to the drive piston and movable along with the drive piston. The rack includes a series of drive teeth. The rack member, along with the drive piston, is movable along a linear movement axis within the open interior of the drive cylinder. 
     The wire gripping assembly includes first and second lever arms that are each pivotally mounted relative to the drive member. The first and second lever arms each include a first end having a series of engagement teeth. The engagement teeth formed on the first end of each of the lever arms mesh with the drive teeth formed on the rack member. When the rack member is moved along the linear movement axis, the engagement between the drive teeth on the rack member and the engagement teeth on the lever arm causes the lever arms to pivot about pivot pins. The pivot pins each define a pivot axis that is generally perpendicular to the linear movement axis of the drive piston and the associated rack member. Preferably, the pivot axis of each of the two lever arms are located on opposite sides of the linear movement axis of the drive piston and the associated rack member. 
     Each of the first and second lever arms are configured to include a gripper jaw that engages the wire being handled when the lever arms are in their engagement position. When the lever arms are in the release position, the gripper jaws separate to release the section of wire. The first and second lever arms can be configured in different orientations depending upon the type of movement of the wire section when the wire section is gripped by the gripper jaws. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the best mode presently contemplated of carrying out the invention. In the drawings: 
         FIG. 1  is a side view of a wire stripping and crimping system that incorporates the wire gripping assembly of the present disclosure; 
         FIG. 2  is a magnified view of the wire gripping assembly taken along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a front perspective view of the wire gripping assembly shown in the gripping position; 
         FIG. 4  is a view similar to  FIG. 3  illustrating the wire gripping assembly in the release position; 
         FIG. 5  is a section view of the wire gripping assembly shown in  FIG. 3 ; 
         FIG. 6  is a section view of the wire gripping assembly shown in  FIG. 4 ; 
         FIG. 7  is a partially exploded view of the wire gripping assembly of  FIGS. 3-4 ; 
         FIG. 8  is a magnified view of a second configuration for the wire gripping assembly; 
         FIG. 9  is a front perspective view of the second configuration in the gripping position; 
         FIG. 10  is a view similar to  FIG. 9  in a release position; and 
         FIG. 11  is an exploded view of the second configuration of the wire gripping assembly shown in  FIGS. 9 and 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  generally illustrates a wire processing system  10 . The wire processing system  10  includes an infeed section  12  that draws a supply of wire into the remaining portions of the system which cuts the wire to length, strips the ends and performs any array of processes to either or both ends of the cut wire section. These processes include and are not limited to crimping, sealing, tinning, twisting, doubling and welding. The wire processing system  10  is controlled by a control unit  14  having a display  16 . The operation of the wire processing station  10  is well known to those of ordinary skill in the art such that the details of the operation will not be described herein. 
       FIG. 2  illustrates a portion of the wire processing system that grabs a section of wire  18  and directs the wire section to a pair of wire cutting and stripping blades  20 ,  22 . The system includes a wire gripping assembly  24  that is selectively operable to grasp the wire section  18  and move the wire section  18  into a desired location. Once again, the movement of the wire gripping assembly  24  to effect the wire cutting and stripping operation is well known to those of ordinary skill in the art. The present disclosure is directed to the specific configuration of the wire gripping assembly  24  shown in  FIG. 2 . 
       FIG. 3  illustrates the wire gripping assembly  24 . The wire gripping assembly  24  is mounted to a support arm  26  such that the entire wire gripping assembly  24  can move to a desired location. The wire gripping assembly  24  generally includes a drive member  28  that controls the movement of a first lever arm  30  and a second lever arm  32  between the gripping position shown in  FIG. 3  and the release position shown in  FIG. 4 . In the embodiment shown in  FIGS. 3 and 4 , both the first lever arm  30  and the second lever arm  32  include a gripper jaw  34  attached to a second end  36  of the respective first and second lever arms  30 ,  32 . The gripper jaws  34  are each removably attached to the lever arms  30 ,  32  by a connector  38 . However, it is contemplated that the gripper jaws  34  could be permanently attached to the first and second lever arms  30 ,  32  while operating within the scope of the present disclosure. 
     As illustrated in  FIG. 3 , when the first and second lever arms  30 ,  32  are in the gripping position, the wire section  18  is grasped between the pair of gripper jaws  34 . In the release position of  FIG. 4 , the gripper jaws  34  are lifted upwards and away from the wire section  18  such that the wire gripping assembly  24  releases the wire section  18 . 
     In the embodiment shown in  FIGS. 3 and 4 , the drive member  28  includes a drive cylinder  40  having a body  42  extending from a first end  44  to a second end  46 . 
     Referring now to  FIG. 5 , the drive cylinder  40  includes an outer wall  48  that defines a generally cylindrical open interior  50 . The first end  44  of the drive cylinder  40  receives a cover member  52 . The cover member  52  includes a pair of connectors  54  that secure the cover member  52  to a plug  56 . The plug  56  includes a recessed groove  58  that in turn receives an annular sealing member  60 . 
     The outer wall  48  transitions into a base wall  62  that defines the bottom surface  64  of the open interior  50 . Base wall  62  includes a mounting section  66  having a front wall  68  and a back wall  70 , as best shown in  FIG. 7 . The front wall  68  and back wall  70  are spaced from each other by an open channel  72  which receives the first lever arm  30  and the second lever arm  32 , as will be described in detail below. 
     Referring back to  FIGS. 5 and 6 , the drive cylinder  40  includes a piston  74  positioned within the open interior  50 . The piston  74  includes an outer seal  76  that engages the inner wall  78 . 
     As illustrated in  FIGS. 5 and 6 , the piston  74  is movable between an upper position shown in  FIG. 5  and a lower position shown in  FIG. 6 . The movement of the piston  74  between the upper position and the lower position is controlled by the application of pressurized air through a first air hose  80  and a second air hose  82 . Both of the air hoses  80 ,  82  include a fitting  84  that allows the pressurized air within the respective air hose  80 ,  82  to be directed through an opening  86  within the open interior  50 . As can be understood in  FIG. 5 , when pressurized air is supplied through the air hose  82 , as illustrated by arrow  88 , the piston  74  moves to its upper position, as indicated by arrow  90 . Referring now to  FIG. 6 , when pressurized air is supplied through the air hose  80 , as illustrated by arrow  92 , the pressurized air above the piston  74  causes the piston to move downward, as illustrated by arrow  94 . As can be understood in  FIGS. 5 and 6 , the application of pressurized air through the air hoses  80 ,  82  controls the movement of the piston  74  from the upper position of  FIG. 5  to the lower position of  FIG. 6 . 
     Referring now to  FIG. 6 , the wire gripping assembly  24  includes a rack member  96  securely attached to the piston  74 . A connector  98  is threadedly received in an upper attachment portion  100  of the rack member  96 . The rack member  96  extends through a cylindrical opening  102  formed in the base wall  62 . The rack member  96  extends through the entire mounting section  66  and into the open channel  72  formed between the front and back walls  68 ,  70 , formed as part of the mounting section  66 . In the embodiment illustrated, a sealing member  104  surrounds the main body of the rack member  96  to prevent pressurized air from flowing around the rack  96 . 
     As illustrated in  FIGS. 5 and 6 , the rack member includes a drive section  106  having a first series of drive teeth  108  and a second series of drive teeth  110 . In the embodiment illustrated, the first and second series of drive teeth  108 ,  110  are identical to each other. However, it is contemplated that the configuration of the drive teeth  108 ,  110  could be varied while operating within the scope of the present disclosure. 
     When the piston  74  moves from the upper position shown in  FIG. 5  to the lower position shown in  FIG. 6 , the entire rack member  96  moves along a linear movement axis generally illustrated by the arrows  90 ,  94 . As described previously, the application of pressurized air through the air hoses  80 ,  82  controls the movement of the piston  74  within the open interior  50 . 
     In the embodiment illustrated in  FIGS. 3 and 4 , each of the first and second lever arms  30 ,  32  includes a first section  112  and a second section  114 . As illustrated in  FIG. 7 , the second section  114  is secured to the first section  112  by a pair of connectors  116 . However, it is contemplated that the first and second sections  112 ,  114  could be integrally formed with each other while operating within the scope of the present disclosure. 
     Referring now to  FIGS. 5 and 6 , the first section  112  of both the first lever arm  30  and the second lever arm  32  includes a first end  118  mounted to the mounting section  66  by a pivot pin  120 . The pivot pin  120  defines a pivot axis extending into the Figure perpendicular to the linear movement axis illustrated by arrow  90 . As illustrated in  FIG. 7 , each of the pivot pins  120  extends through both the front wall  68  and the back wall  70  and defines the pivot axis for the first lever arm  30  and the second lever arm  32 . 
     Referring back to  FIGS. 5 and 6 , the first end  118  of both of the first and second lever arms  30 ,  32  includes a radiused movement surface  122 . Each of the movement surfaces  122  include a plurality of engagement teeth  124 . The engagement teeth  124  on the first lever arm  30  engage the first set of drive teeth  108  while the engagement teeth  124  on the second lever arm  32  engage the second set of drive teeth  110  formed on the rack member  96 . The spacing between the engagement teeth  122  and the first and second set of drive teeth  108 ,  110  is identical to provide smooth interaction between the mating teeth. 
     As the rack member  96  moves downward, as indicated by arrow  94  in  FIG. 6 , the downward movement of the rack member  96  causes the first and second lever arms  30 ,  32  to pivot from the gripping position of  FIG. 5  to the open position of  FIG. 6 . Conversely, when the rack member  96  moves upward in the direction shown by arrow  90  in  FIG. 5 , the movement of the rack member  96  causes the first and second lever arms  30 ,  32  to move from the open position shown in  FIG. 6  to the closed, gripping position shown in  FIG. 5 . As described, the application of pressurized air through the air hoses  80 ,  82  moves the piston  74 , which in turn results in movement of the rack member  96 . The interaction between the drive teeth  108 ,  110  on the rack member and the corresponding engagement teeth  124  on the first end of the first and second lever arms  30 ,  32  results in the movement of the first and second lever arms  30 ,  32  between the gripping position of  FIG. 5  and the release position of  FIG. 6 . 
     Referring now to  FIG. 7 , the wire gripping assembly  24  includes a cover plate  126  attached to the front wall  68  by a connector  128 . The cover plate  126  covers the pair of pivot pins  120 . 
       FIG. 8  illustrates a second configuration of a wire gripping assembly  24  constructed in accordance with the present disclosure. The second configuration shown in  FIG. 8  includes many of the same operating components as the first configuration of  FIGS. 1-7 , as will be described in greater detail below. 
     As illustrated in  FIG. 9 , the second configuration of the wire gripping assembly  24  includes a modified mounting arrangement  129 . However, the wire gripping assembly  24  includes an identical drive cylinder  40  including the pair of air hoses  80 ,  82 . The internal operation of the drive cylinder  40  is identical to that described with reference to  FIGS. 5 and 6 . 
     In the embodiment shown in  FIGS. 9 and 10 , the wire gripping assembly includes both a first lever arm  130  and a second lever arm  132 . However, in the embodiments of  FIGS. 9 and 10 , the lever arms  130 ,  132  are slightly different than the lever arms  30 ,  32  shown in the first embodiment of  FIGS. 5 and 6 . In the second embodiment shown in  FIGS. 9 and 10 , both of the lever arms include the same first section  112 . However, instead of including the horizontal, second section  114 , the lever arms shown in  FIGS. 9 and 10  include the gripper jaws  34  mounted directly to the first section  112  through the connector  134 . As can be understood in  FIGS. 9 and 10 , the first sections  112  are each movable between the gripping position shown in  FIG. 9  and the release position shown in  FIG. 10 . 
     As illustrated in  FIG. 11 , a wire guide  136  is mounted to the front wall  68  by a series of connectors  138 . The wire guide  136  covers the pivot pins  120  in the same manner as the cover plate  126  shown in  FIG. 7 . As can be understood in a comparison of  FIGS. 7 and 11 , the wire gripping assembly  24  is identical in both configurations. However, the first and second lever arms  30 ,  32  are configured differently in the embodiment of  FIGS. 7 and 11  to carry out different wire gripping and moving functions. The operation of the wire gripping assembly  24 , and specifically the use of the moving rack member and rotating lever arms are identical in both embodiments. 
     Although the wire gripping assembly  24  shown in both configurations of the drawing figures includes an air cylinder, it is contemplated that the air cylinder could be removed and replaced with other types of drive mechanisms. As an example, an electronically activated solenoid could be utilized to move the rack member relative to the first and second lever arms  30 ,  32 . Other types of driving arrangements are also contemplated as being within the scope of the present disclosure. 
     Further, although a source of pressurized air was shown and described as being coupled to the pair of supply hoses  80 ,  82 , various other types of pressurized liquid could be utilized while operating within the scope of the present disclosure. Pressurized air is contemplating as being utilized in the preferred embodiment due to the availability and ease of use of pressurized air. However, other embodiments are contemplated as being within the scope of the present disclosure.