Patent Publication Number: US-9425572-B2

Title: Methods of connecting cables with an installation tool

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional application of Ser. No. 13/607,989, filed Sep. 10, 2012, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/573,148, filed Sep. 14, 2011, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a limit indicator for a ram of a wedge connector. Still more particularly, the present invention relates to a limit indicator for preventing over-torquing of a ram of a wedge connector prior to installation. 
     BACKGROUND OF THE INVENTION 
     A wedge connector includes an installation tool that drives a wedge into a sleeve to electrically and mechanically connect two cables. The two cables are passed through the sleeve on opposite sides of the wedge. Conventional installation tools use a powder cartridge to obtain a sufficient force to drive the wedge into the sleeve to securely retain the cables between the wedge and the sleeve. 
     In a non-firing position, a spring spaces a firing pin from a load cell in the installation tool. Torque is applied to the installation tool to compress the spring and move the load cell adjacent to the firing pin, thereby putting the installation tool in a firing position. 
     However, problems have occurred in operating conventional installation tools in removing the tools from installed wedges. When readying the installation tool for firing, users can over-torque the installation tool when compressing the spring. The over-torquing causes the ram to start to push the wedge into the sleeve. When the installation tool is fired, gas is generated in the tool housing to drive the wedge into the sleeve. Over-torquing the installation tool causes the ram to start to push the wedge into the sleeve such that some of the generated gas remains in the tool housing after the wedge has been driven by the ram. The gas remaining in the tool housing keeps a piston in engagement with the ram, thereby making removal of the installation tool difficult. Accordingly, a need has been discovered for a wedge connector in which over-torquing of the installation tool is substantially prevented. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an installation tool that prevents over-torquing of an installation tool. 
     Another object of the present invention is to provide an installation tool in which the installation tool is easily removed from the wedge after installation. 
     In accordance with an aspect of the present invention, a wedge connector assembly includes an installation tool having a tool body and a frame connected to the tool body. A sleeve is received by the frame and a wedge is received by the sleeve. A firing mechanism is movably connected to the tool body. A movable ram extends from the tool body into the frame such that movement of the ram drives the wedge into the sleeve when the installation tool is fired. A piston is movably disposed in the tool body between the ram and the firing mechanism. The piston is moved when the firing mechanism is activated, thereby driving the wedge into the sleeve. An indicator disposed on the ram indicates when the installation tool is in a proper firing position to substantially prevent over-torquing the installation tool. 
     In accordance with another aspect of the present invention, a method is provided of connecting cables with an installation tool. A tool body is rotated to put the installation tool in a firing position. The rotation of the tool body is stopped when indicated by an indicator to substantially prevent over-torquing the installation tool. A firing mechanism is activated to drive a wedge into a sleeve to secure the cables between the wedge and the sleeve. 
     Objects, advantages, and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses an exemplary embodiment of the present invention. 
     As used in this application, the terms “front,” “rear,” “upper,” “lower,” “upwardly,” “downwardly,” and other orientational descriptors are intended to facilitate the description of an exemplary embodiment of the present invention, and are not intended to limit the structure thereof to any particular position or orientation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above benefits and other advantages of the various embodiments of the present invention will be more apparent from the following detailed description of exemplary embodiments of the present invention and from the accompanying drawing figures, in which: 
         FIG. 1  is a perspective view of a wedge connector in accordance with an exemplary embodiment of the present invention; 
         FIG. 2  is a perspective view of an installation tool in a firing position; 
         FIG. 3  is a perspective view of an installation tool in a non-firing position; 
         FIG. 4  is a partial side elevational view of a ram of the installation tool of  FIG. 2 ; 
         FIG. 5  is a partial side elevational view of a ram of the installation tool of  FIG. 3 ; 
         FIG. 6  is a top plan view in partial cross section of the wedge connector of  FIG. 1  in which the installation tool is in a non-firing position; and 
         FIG. 7  is a top plan view in partial cross section of the wedge connector of  FIG. 1  in which the installation tool is in a firing position. 
     
    
    
     Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT 
     The wedge connector  11  includes an installation tool  21 , a frame  41 , a sleeve  61  and a wedge  81 , as shown in  FIGS. 1, 6 and 7 . The installation tool  21  drives the wedge  81  into the sleeve  61  to securely retain wires, or conductors,  13  and  15  between the wedge  81  and the sleeve  61 , thereby electrically connecting the wires  13  and  15 . 
     The frame  41  has a front end  42  forming an anvil section  43 . The anvil section  43  includes a sleeve receiving portion  44  for receiving a front end  63  of a sleeve  61 . A rear end  45  of the frame  41  forms a tool supporting portion  46  having a threaded bore  47  for receiving a threaded portion  22  of a tool body  23 . The threaded portion  22  of the tool body  23  is threaded through the bore  47  of the frame  41  to support the installation tool  21  and align a ram  91  of the installation tool  21  with a longitudinal axis of the frame  41 . 
     The tool body  23  includes an end bearing  24  connected to the threaded portion  22 , as shown in  FIGS. 2-5 . A firing mechanism is connected to the tool body  23  to activate the installation tool  21  when in the firing position. A chamber  25  in the tool body  23  receives a booster assembly  26 , as shown in  FIGS. 6 and 7 . The booster assembly  26  includes a sleeve  27 , a piston  28  and a power cell  29 , such as a cartridge, as shown in  FIGS. 6 and 7 . The piston  28  and power cell  29  are disposed within the sleeve  27 . The spring member  30  biases the firing pin  31  away from the power cell  29  to prevent accidentally exploding the power cell, as shown in  FIG. 6 . 
     The ram  91  is movably disposed in the tool body  23 , as shown in  FIGS. 6 and 7 . A first end  92  of the ram  91  extends externally of the end bearing  24 . A second end  93  of the ram  91  is disposed within the tool body  23  and abuts the piston  28  within the sleeve  27  of the booster assembly  26 . An inner bearing  33  is disposed on an outer surface  94  of the ram  91  to permit axial movement of the ram  91  through a bore  34  of the tool body  23 . An identifier  97 , such as a trademarked logo, can be disposed on the first end  92  of the ram  91 . The identifier  97  is imprinted on the wedge  81  when the wedge is driven into the sleeve  61  by the ram  91 . 
     A limit indicator  95  is disposed on the outer surface  94  of the ram  91  proximal the first end  92 , as shown in  FIGS. 3, 5 and 6 . Installation tool  21 , except for the limit indicator  95 , is conventional and is disclosed further in the English portion of the 2011 Burndy Safety Operating &amp; Maintenance Instructions for the Burndy WEJTAP System, the entire disclosure of which is hereby incorporated by reference (available from the Burndy Tool Service Center in Littleton, NH). The tool body  23  is rotated to put the installation tool  21  in a firing position, as shown in  FIG. 7 . The end bearing  24  rotates with the tool body  23 . When the end bearing  24  is moved over the limit indictor  95  such that the limit indicator  95  is no longer visible, the installation tool  21  is in the firing position. Accordingly, the user knows to stop rotating the tool body  23  when the limit indicator  95  is no longer visible, as shown in  FIG. 7 , thereby substantially preventing over-torquing. The limit indicator  95  can be any type of indicator on the ram  91  that is visible to the user. For example, the limit indicator  95  can be, but is not limited to, a line painted on an outer surface of the ram  91 , a groove formed in the outer surface of the ram  91 , a line painted in a groove formed in the outer surface of the ram  91 , or an indicator ring disposed on an outer surface of the ram  91 . The limit indicator  95  can be a permanent indicator or a temporary indicator that wears off over time as the user becomes more familiar with the installation tool  21 . 
     In a non-firing position, as shown in  FIGS. 3, 5 and 6 , the spring  30  biases the firing pin  31  away from the power cell  29 , thereby substantially preventing accidentally exploding the power cell. The limit indicator  95  on the ram  91  is visible when the installation tool is in a non-firing position. The first end  92  of the ram  91  contacts the first end  83  of the wedge  81 . 
     To put the installation tool  21  in a firing position, as shown in  FIGS. 2, 4 and 7 , the tool body  23  is rotated to overcome the biasing force of the compression spring  30 . The tool body  23  is rotated resulting in axial movement of the tool body  23 , including the end bearing  24 . The inner bearing  33  allows the tool body  23  to be rotated about the ram  91  without moving the ram. Axial movement of the tool body  23  results in the spring  30  being compressed and the firing pin  31  being moved to a position abutting the power cell  29 . The axial movement of the tool body  23  also results in axial movement of the end bearing  24 , which covers the limit indicator  95 . When the limit indicator  95  is no longer visible, the proper torque is obtained for firing the installation tool  21 . The user stops rotating the tool body  23 , thereby substantially preventing over-torquing of the installation tool  21 . Accordingly, by substantially preventing over-torquing, the user is prevented from beginning to insert the wedge  81  into the sleeve  61 . 
     To fire the installation tool  21 , a hammer, or other suitable tool, is used to strike the firing button  32 . The inward axial movement (to the left in  FIG. 7 ) of the firing button  32  causes axial movement of the firing pin  31 , which penetrates the power cell  29  and causes the power cell  29  to explode. The gas generated by the explosion of the power cell  29  moves the piston  28  axially causing the piston to strike the ram  91 , which is driven axially through the bore  34  of the tool body  23 . The first end  92  of the ram  91  pushes the wedge  81  further into the sleeve  61 , thereby mechanically securing the cables  13  and  15  between the wedge  81  and the sleeve  61 . When the piston  28  and ram  91  stop moving, the piston  28  welds to the inner wall of the sleeve  27 , thereby storing the generated gas pressure behind the piston. When the installation tool  21  is turned off, the stored generated gas vents through the piston  28  and down through the bore  34 . The gas exits the tool  21  between the ram  91  and the end bearing  24 . 
     When the installation tool  21  is not over-torqued, the generated gases are expelled from the tool body  23 . The tool body  23  can then be rotated away from the wedge  81  creating a gap between the piston  28  and the second end  93  of the ram  91 , such that the ram  91  can be moved away from the wedge  81 . The installation tool  21 , including the frame  41 , can be removed from the sleeve  61  and wedge  81 . The used booster assembly  26  can then be removed from the tool body  23  and replaced with a new booster assembly to electrically and mechanically connect two other cables with another sleeve  61  and wedge  81 . 
     When a user over-torques the tool body  23 , the power cell  29  and piston  28  begin to push the second end  93  of the ram  91  such that the ram  91  starts pushing the wedge  81  into the sleeve  61 . Thus, when the installation tool  21  is fired, the wedge  81  does not need to be pushed as far into the sleeve  61  because the wedge  81  has already been partially pushed into the sleeve  61  by over-torquing the tool body  23 . Thus, not all of the gas generated by the exploding power cell  29  is used to drive the ram  91 . The remaining gas makes axial movement of the ram  91  away from the wedge  81  (to the right in  FIG. 7 ) extremely difficult after the wedge has been installed, thereby making removal of the installation tool  21  from the assembled sleeve  61  and wedge  81  extremely difficult. By providing the ram  91  with a limit indicator  95  to prevent over-torquing the installation tool  21 , this problem is substantially prevented and the installation tool  21  can be easily removed following use. 
     The foregoing embodiment and advantages are merely exemplary and are not to be construed as limiting the scope of the present invention. The description of an exemplary embodiment of the present invention is intended to be illustrative, and not to limit the scope of the present invention. Various modifications, alternatives and variations will be apparent to those of ordinary skill in the art, and are intended to fall within the scope of the invention as defined in the appended claims and their equivalents.