Patent Publication Number: US-6220074-B1

Title: Electrical connector crimping tool head

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical connector crimping tools and, more particularly, to a tool head for connection to a rotatable drive. 
     2. Prior Art 
     U.S. Pat. Nos. 4,942,757 and 5,062,290 disclose hydraulic crimping presses for electrical connectors. The tool heads include a general C-shaped frame, a ram movably connected to the frame, and dies for compressing or crimping an electrical connector. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the present invention, an electrical connector crimping tool head is provided comprising a frame; and a ram movably connected to the frame. The ram comprises a first member and a second member longitudinally movable along the first member. The first member comprises a shaft section removably insertable into a rotatable drive for a fixed connection to the rotatable drive. 
     In accordance with another embodiment of the present invention, an electrical connector crimping tool head is provided comprising a frame; and a ram movably connected to the frame. The ram comprises a first member and a second member movably connected to the first member. The first member is rotatably connected to the frame in a substantially fixed longitudinal position. The second member is longitudinally movable on the first member as the first member is rotated relative to the frame. 
     In accordance with another embodiment of the present invention, an electrical connector crimping tool head is provided comprising a frame; and a ram movably connected to the frame. The ram comprises a first member rotatably connected to the frame and a second member movably connected to the first member and the frame. The second member comprises a section connected to the frame for preventing the second member from rotating relative to the frame. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects and other features of the present invention are explained in the following description, taken in connection with the accompanying drawings, wherein: 
     FIG. 1 is a cross-sectional view of an electrical connector crimping tool head incorporating features of the present invention; 
     FIG. 2 is a side elevational view with a partial cross-section of another embodiment of the present invention; 
     FIG. 3A is a perspective view of an alternate embodiment of the present invention; 
     FIG. 3B is a side elevational view of the embodiment shown in FIG. 3A; 
     FIG. 4A is a top plan view of another alternate embodiment of the present invention; and 
     FIG. 4B is a side elevational view of the embodiment shown in FIG.  4 A. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, there is shown cross-sectional view of a tool head  10  incorporating features of the present invention. Although the present invention will be described with reference to the embodiments shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used. 
     In this embodiment the tool head  10  is for compressing or crimping electrical connectors (not shown) onto conductors (not shown). However, in alternate embodiments, the tool head could be configured as a cutting device with cutting blades instead of crimping dies. In this embodiment the tool head  10  is adapted to be removably connected to a drive, such as the drive unit  12  shown in FIG.  2 . However, in an alternate embodiment the tool head  10  could be non-removably connected to a suitable drive. 
     The tool head  10  generally comprises a frame  14  and a ram  16 . The frame  14  generally comprises a first frame member  18  and a second frame member  20 . In this embodiment the first frame member  18  has a general C-shaped profile. However, in alternate embodiments any suitable shape could be provided. The interior side of the middle of the first frame member  18  includes a slot  23 . The top of the first frame member  18  has an area  22  for removably receiving a first crimping die  24 . A second crimping die  26  is removably connected to the ram  16 . However, in alternate embodiments, the dies  24 ,  26  could be fixedly, non-removably connected to the first frame member  18  and the ram  16 , respectively. In another alternate embodiment the dies need not be provided, such as when electrical connectors are crimped directly by and between surfaces of the frame and ram. In another alternate embodiment the dies  24 ,  26  could be cutting dies having cutting blades. In this embodiment each of the dies  24 ,  26  have three crimping areas  27   a ,  27   b ,  27   c  for crimping three different sized electrical connectors. However, the dies could have more or less than three crimping areas. The bottom of the first frame member  18  includes an aperture  28  and a flange  30  with threads. The second frame member  20  has a general cap shape with a flange  32  having interior threads and an end  34 . The end  34  comprises an aperture  36 . The second frame member  20  is attached to the first frame member  18  by the threads at the flanges  30 ,  32 . However, in alternate embodiments, any suitable means could be used to connect the two frame members to each other. 
     The ram  16  generally comprises a first ram member  40  and a second ram member  42 . The first ram member  40  generally comprises a center section  44 , a first end  46  and an opposite second end  48 . The first end  46  is preferably provided as a shaft section with a general polygon cross-section. However, the first end  46  could have any suitable shape. The center section  44  includes an annular flange  50 . The second end  48  comprises screw threads  52  on an exterior side. The second ram member  42  generally comprises a main section  54  having an aperture  56 , a die receiving area  58 , and a laterally extending section  60 . The aperture  56  is threaded. The second end  48  of the first ram member  40  extends into the aperture  56  and its threads  52  engage the threads of the aperture  56 . The die  26  is removably connected to the second ram member  42  at the die receiving area  58 . The laterally extending section  60  extends into the slot  23  of the first frame member  18 . The section  60  is smaller in height than the slot  23  such that the section  60  can move up and down in the slot. 
     The center section  44  of the first ram member  40  is located in the apertures  28 ,  36  of the frame members  18 ,  20 . A first bearing  62  is located between the center section  44  and the first frame member  18  at a narrow section  28   a  of the aperture  28 . A second bearing  64  is located between the annular flange  50  of the first frame member  40  and the inside surface of the end  34  of the second frame member  20  inside a larger section  28   b  of the aperture  28 . The annular flange  50  of the first ram member  40  is located in the larger section  28   b  of the aperture  28  against a containment surface  66 . The annular flange  50  is captured between the containment surface  66  on one side and the bearing  64  and end  34  of the second frame member  20  on the other side. The first ram member  40  is, thus, substantially prevented from longitudinally moving relative to the frame  14 . However, the first ram member  40  is axially rotatable relative to the frame  14 . In alternate embodiments any suitable connection of the first ram member to the frame could be provided. 
     As noted above, the two ram members  40 ,  42  are connected to each other by screw threads. The connection of the second ram member  42  to the first frame member  18 , by means of the laterally extending section  60  extending into the slot  23 , prevents the second ram member  42  from axially rotating relative to the first frame member  18 . Also as noted above, the first ram member  40  is longitudinally constrained relative to the frame  18 . Thus, when the first ram member  40  is axially rotated, the second ram member moves along the threads  52  of the first ram member  40  to longitudinally move relative to the frame  14  as indicated by arrow A. Rotation of the first ram member  40  in a first direction will move the die  26  towards the die  24 . Rotation of the first ram member  40  in an opposite second direction will move the die  26  away from the die  24 . In an alternate embodiment any suitable rotation-to-translation connection could be provided between the two ram members, such as a peg and groove connection. In addition, any suitable rotation prevention system could be provided on the second ram member, such as a portion of the frame extending into a slot in the second ram member. 
     The shaft section formed by the end  46  of the first ram member  40  is preferably sized and shaped to be removably received in a receiving hole of a rotatable drive. One embodiment of a drive is shown in FIG.  2 . In this embodiment the drive  12  is an electrically powered drill unit comprising an electric motor  70 , a battery  72 , a housing  74 , an activation trigger  76 , and a rotatable connector  78  connected to the motor  70 . The rotatable connector  78  is adapted to removably receive members to be rotated, such as drill bits. The connector  78  has a receiving hole  80  and a suitable clamping or chuck mechanism for clamping onto a shaft located in the hole  80 . Electric powered drill units are readily available in any suitable hardware store or hardware department in a retail store. In one embodiment, the drill unit could be a drill driver which comprises different torque levels or drive modes. Such drive modes could include an overrun mode wherein a clutch type of mechanism disengages when a certain predetermined torque level is obtained. This can help to prevent over-crimping of a connector. In alternate embodiments, any suitable rotatable drive unit could be used, such as a drill unit which is connected by a cord to a main power supply or even a rotatable pneumatically operated drill unit. 
     One of the advantages of the present invention is the ability to use the tool head  10  with a conventional rotatable drill unit which the customer may already own. Thus, tool head  10  can be sold without its own drive unit thereby reducing the cost of tooling to the customer who already owns a rotatable drill unit. In addition, the present invention allows a user to use a conventional rotatable drill unit both for drilling (with the use of drill bits) and for crimping electrical connectors or cutting conductor by use of the tool head of the present invention. 
     Referring now to FIG. 2, another embodiment of the present invention will be described. In this embodiment the tool head  100  generally comprises a frame  102 , a ram  104 , and a stabilizer  106 . The stabilizer  106  connects the frame  102  to a handle  75  of the drill unit  12  to prevent the frame  102  from rotating relative to the housing  74 . A portion of the stabilizer can extend through a hole in the frame  102  and/or wrap around a bottom portion of the frame. In alternate embodiments any suitable type of stabilization or rotation prevention system could be provided between the frame of the tool head and the drive unit. Any suitable system could be used to connect the shaft section of the ram to the frame. The first ram member  108  can have a shaft section  110  that extends through a single diameter hole  112  of the frame  102  and is longitudinally retained by a spring clip  114 . The end  116  has an enlarged diameter to also prevent the member  108  from moving out of the hole. Thus, only a one piece frame is needed rather than a two piece frame as in FIG.  1 . The end  116  is threadingly engaged with the second ram member  109 . The second ram member  109  has a slot  118  on one side which receives a portion of the frame  102  to prevent the second ram member  109  from rotating relative to the frame  102 . 
     Referring now to FIGS. 3A and 3B an alternate embodiment of the present invention is shown. In this embodiment the tool head  200  generally comprises a frame  202 , a ram  204 , and a stabilizer  206 . The stabilizer  206  generally comprises a one-piece bar  208 . The bar  208  has a general “U” shape with two spaced bar sections  210 ,  211 . Ends  212  of the bar sections  210 ,  211  are connected to the frame  202  by fasteners  214 , such as screws. The stabilizer  206  receives the handle  75  of the drill unit  12  in the space  216  between the two bar sections  210 ,  211 . Thus, the stabilizer  206  provides an anti-rotation and holding feature which is linked to the distal end of the tool handle. This increases the lever arm to counterbalance the torque. Also, the ease of assembly is increased versus the design shown in FIG. 2 since the linking structure is a simple generally U shaped link designed to be easily inserted on the tool body and attached to the crimping head. Other means could be used to attach the stabilizer bar to the frame, such as force fit insertion or a detent mechanism. The stabilizer solves the problem of the frame spinning with the drive. In addition, the user does not need to hold the frame with his hand to prevent spinning of the frame. This avoids the potential problem of pinching the user&#39;s fingers. 
     Referring now to FIGS. 4A and 4B, an alternate embodiment of the present invention is shown. In this embodiment the tool head  300  generally comprises a frame  302 , a ram  304 , and a stabilizer  306 . The stabilizer  306  generally comprises two bars  310 ,  311  and a mount  312 . The mount  312  generally comprises two members  314 ,  315  connected to each other by fasteners  316 . The mount  312  forms an aperture  318 . A resilient bumper  320  could be located in the aperture  318  to directly contact the front of the housing  74  of the drill unit  12  proximate the rotating connector  80 . The connection of the mount  312  to the front of the housing  74  prevents the mount from rotating relative to the housing. The rotating connector  80  can pass through the aperture  318  to be connected to the shaft section of the ram  304 . The two bars  310 ,  311  are fixedly connected in holes of the mount  318  and holes in the frame  302 . This forms the mount/bars/frame as a rigid structure. Thus, the frame  302  is rigidly connected to the housing  74 . This design may allow the system to be fitted on tools having different drive head sizes since the bars may be slidably, non-fixedly connected in the holes of the collar  312 . Also, the collar  312  may be made of a hard material adapted to the shape of the housing rotatable behind the drive head or a material with some resilience which could conform itself to the rotatable drive head shape. The collar and anti-rotation bars may be adapted in terms of resilience to absorb part of the end of stroke torque peak. 
     It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.