Abstract:
A wiring connector back shell having a plurality of cable exit angles is disclosed. The back shell has a single transition element with a number of holes fashioned therein, which allow a cable retaining device to be fastened thereto. The cable retaining device provides strain relief for the cable exiting the back shell, as well as determining the exit angle of the cable. The cable retaining device has integral pins which mate with hole patterns in the transition element, and are locked in place with a retaining collar. Alternatively, cable ties or tie wraps may be utilized to fasten the cable to the transition element. The system provides a high reliability, low mass method for cable back shells wherein cable exit angles are easily changed or chosen in the field.

Description:
REFERENCES TO PRIOR APPLICATIONS 
       [0001]    This application is related to co-pending provisional application, reference No. 61/203,250, filed Dec. 19, 2008, entitled CONNECTOR BACKSHELLS HAVING A PLURALITY OF CABLE EXIT ANGLES, and claims benefit thereof. Provisional application No. 61/203,250 is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to the design and structure of electrical connectors. More specifically, the invention relates to connector back shell designs having the ability to provide a number of cable exit angles and cable strain relief with a single set of components. 
         [0004]    2. Description of the Related Art 
         [0005]    A back shell is a device used in wire interconnect assemblies to transition from a plurality of insulated conductors (a plurality of wires or cable) to an electrical connector. The electrical connector will have conductive devices, usually in the form of pins or sockets, to which each of the conductors from the cable is terminated. The pins or sockets are held in a specific geometric arrangement within the shell of the connector, in order to mate with a matching connector having a similar arrangement of conductive pins or sockets. The wire from each of the conductors in the cable is attached to the pins or sockets in the electrical connector via soldering, crimping, or welding. These means of attachment can be subject to breakage if stresses from the wire cable are transmitted to the attachment points. In most cases, the back shell will provide some means for securing the wires or cable such that any forces acting upon the wires or cable will not be imposed on the wire connections and at the end of the wires. This is referred to as “strain relief” and is an important function performed by the back shell. In many cases this function is performed by either saddle clamps or banding platforms to accommodate either metallic or plastic bands. Another important function of the back shell is to direct the wire cable in a particular direction as it exits the connector. Typically, this is done with a short section of hollow conduit through which the cable is inserted. These are often manufactured with a fixed orientation such as straight (0 degrees), 45 degrees, or 90 degrees, and are an integral part of the back shell construction. 
         [0006]    One problem experienced by connector users is that once a cable is terminated into a particular connector and back shell orientation, changing that orientation during assembly in the field can be difficult. Even if the connector design allows multiple back shell orientations to be utilized without re-terminating the cable, the user still has to purchase and stock many back shell components for this purpose, which can be expensive. It would be desirable to have a back shell design that allows a plurality of cable exit angles with a single set of components that are an integral part of the back shell. 
         [0007]    One such design is currently available which incorporates a means to overcome this problem. U.S. Pat. No. 6,419,519 discloses a design where the wire securing mechanism is at the end of dual arms that swing or pivot to adjust to different angular increments. Hardware then secures the assembly in place. Whilst this method meets the requirement of being able to accommodate multiple orientations of wire containment with a single back shell, it is burdened with multiple screws and hardware components, each requiring adjustment, and each having the ability to come loose becoming FOD (Foreign Object Debris) in high stress and/or critical applications. The design is also complex, and adjustment of cable direction may be difficult if the connector is terminated and there is no access to all the adjustment mechanisms. 
         [0008]    What is needed is a more reliable, simple back shell design that provides appropriate strain relief while allowing a plurality of cable exit angles with a single set of components integrated into the back shell. 
       SUMMARY OF THE INVENTION 
       [0009]    It is an object of the present invention to provide a connector back shell, said connector back shell operative to provide support for a wiring cable attached to a wiring connector, the connector back shell including a forward section having a hollow cylindrical shape, the cylindrical shape defining a first axis, the forward section operative to couple the connector back shell to the wiring connector; a transitional element, the transitional element comprising a plate having a first straight edge, the first straight edge positioned approximately parallel to the first axis, the plate having a second straight edge, the second straight edge positioned approximately perpendicular to the first straight edge; a connecting element, the connecting element operative to rigidly couple the transitional element to the forward section, the connecting element rigidly fixed to at least a portion of the second straight edge of the plate; and a cable retaining device, the cable retaining device attached to the plate of the transitional element, the cable retaining device operative to position the wiring cable relative to a first angle. 
         [0010]    It is an object of the present invention to provide a connector back shell, said connector back shell operative to provide support for a wiring cable attached to a wiring connector, the connector back shell including a forward section having a hollow cylindrical shape, the cylindrical shape defining a first axis, the forward section operative to couple the connector back shell to the wiring connector; a transitional element, the transitional element comprising a plate having a first straight edge, the first straight edge positioned approximately parallel to the first axis, the plate having a second straight edge, the second straight edge positioned approximately perpendicular to the first straight edge, the plate of the transitional element having a plurality of holes fashioned therein, the plurality of holes located in a pattern, the pattern symmetric about a second axis, the second axis defined by bisection of a second angle formed by the first and second straight edges of the plate; a connecting element, the connecting element operative to rigidly couple the transitional element to the forward section, the connecting element rigidly fixed to at least a portion of the second straight edge of the plate; and a cable retaining device, the cable retaining device attached to the plate of the transitional element, the cable retaining device operative to position the wiring cable relative to a first angle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The present invention will be better understood when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings, wherein: 
           [0012]      FIGS. 1   a  and  1   b  are isometric views of back shells employing a single transitional element, in accordance with an embodiment of the present invention; 
           [0013]      FIG. 1   c  is a side view of the back shells of  FIGS. 1   a  and  1   b , in accordance with an embodiment of the present invention; 
           [0014]      FIG. 1   d  is an expanded view of the elongated holes  110  of  FIG. 1   c , in accordance with an embodiment of the present invention; 
           [0015]      FIG. 2   a  is an isometric view of a back shell employing a tie wrap to maintain a cable exit angle of approximately 0 degrees, in accordance with an embodiment of the present invention; 
           [0016]      FIG. 2   b  is a side view of a back shell employing a tie wrap to maintain a cable exit angle of approximately 45 degrees, in accordance with an embodiment of the present invention; 
           [0017]      FIG. 2   c  is a side view of a back shell employing a tie wrap to maintain a cable exit angle of approximately 90 degrees, in accordance with an embodiment of the present invention; 
           [0018]      FIG. 3   a  is an isometric view of a back shell employing dual split pins and a retaining collar, to maintain a cable exit angle of approximately 0 degrees, in accordance with an embodiment of the present invention; 
           [0019]      FIG. 3   b  is an isometric view of a back shell employing dual split pins and a retaining collar, to maintain a cable exit angle of approximately 45 degrees, in accordance with an embodiment of the present invention; 
           [0020]      FIG. 3   c  is an isometric view of a back shell employing dual split pins and a retaining collar, to maintain a cable exit angle of approximately 90 degrees, in accordance with an embodiment of the present invention; 
           [0021]      FIG. 3   d  is an isometric exploded assembly view of the back shell of  FIG. 3   b , in accordance with an embodiment of the present invention; 
           [0022]      FIG. 3   e  is an isometric, partial cross sectional view of the back shell of  FIG. 3   b , in accordance with an embodiment of the present invention; 
           [0023]      FIG. 3   f  is a side view of the back shells of  FIGS. 3   a - 3   e , in accordance with an embodiment of the present invention; 
           [0024]      FIG. 3   h  is an expanded side view of the elongated holes  310  of  FIG. 3   f , in accordance with an embodiment of the present invention; 
           [0025]      FIG. 4   a  is an isometric view of a back shell employing dual cylindrical pins and a retaining collar, to maintain a cable exit angle of approximately 45 degrees, in accordance with an embodiment of the present invention; 
           [0026]      FIG. 4   b  is an isometric view of a back shell employing dual cylindrical pins and a retaining collar, to maintain a cable exit angle of approximately 0 degrees, in accordance with an embodiment of the present invention; and 
           [0027]      FIG. 4   c  is an isometric view of a back shell employing dual cylindrical pins and a retaining collar, to maintain a cable exit angle of approximately 90 degrees, in accordance with an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]      FIGS. 1   a  and  1   b  are isometric views  100 ,  101  of back shells  102  employing a single transitional element  108 , in accordance with an embodiment of the present invention. These embodiments are improvements over back shells having two transitional elements (as for example, are disclosed in U.S. Pat. No. 6,419,519) due to simplicity of design and manufacture. This simplicity results in back shells of lower weight and reduced number of moving parts. Both features are important in aerospace and aircraft applications. Back shell  102  comprises a cylindrically shaped forward section  104 , which supports transitional element  108  via connecting element  106 . Transitional element  108  has a number of “elongated” holes  110   a - 110   d  fashioned therein. An elongated hole is one in which the length is greater than the width. These elongated holes  110  provide attachment points for a cable retaining device, which provides strain relief and fixes the direction of the wire cable exiting the back shell. Back shell  102  also comprises a threaded hexagonal component (shown) that revolves around forward section  104 , which is utilized to couple back shell  102  to the wiring connector (not shown). The wiring connector contains an array of pins or sockets to which the individual conductors within the wire cable are attached (not shown). 
         [0029]      FIG. 1   c  is a side view  103  of the back shells  102  of  FIGS. 1   a  and  1   b , in accordance with an embodiment of the present invention. Transitional element  108  is cross hatched for clarification of its geometric boundaries and properties. Cylindrically shaped forward section  104  defines an axis of symmetry  118  through the center of the back shell  102 . Transitional element is bounded by two orthogonal edges  112  and  114 . Edge  112  is parallel to axis  118 . Edge  114  is orthogonal to edge  112  (and axis  118 ), and provides the connection interface to connecting element  106 . Angle  120 , defined by axis  116 , resides within the angle formed by the intersection of edges  112  and  114 , and ranges from 0 to 90 degrees. Preferably, angle  120  bisects the angle between the angle formed by the intersection of edges  112  and  114 , and is approximately 45 degrees. There are a number of “elongated” holes or ports fashioned within transitional element  108 , whose purpose is to provide attachment locations for the cable retaining device. An elongated hole is one having a length greater than its width. The embodiments of  FIGS. 1   a - c  are designed primarily for tie wraps, cable ties, or “zip” ties, but can be used with cable retaining devices having fixed pins that extend through one or more holes  110 , such as those shown below in  FIGS. 3   a - e.    
         [0030]    The elongated holes  110  placed within transitional element  108  have a specific geometric orientation. Elongated hole  110   a  is placed with its longest dimension parallel to edge  112  or axis  118 . Elongated hole  110   d  is placed with its longest dimension parallel to edge  114 , or perpendicular to edge  112 . Elongated holes  110   b,c  are placed with their longest dimension parallel to axis  116 .  FIG. 1   d  is an expanded view  105  of the elongated holes  110  of  FIG. 1   c . The length  122  of hole  110  is greater than the width, with axis  124  is parallel to the direction of the longest dimension. 
         [0031]      FIG. 2   a  is an isometric view  200  of a back shell  102  employing a tie wrap  204  to maintain a cable exit angle of approximately 0 degrees, in accordance with an embodiment of the present invention. Cable  202  is held in place via tie wrap  204 , which extends around cable  202  and through elongated hole  110   a . The flat surface of the tie wrap, combined with the shape of the elongated hole, maintains the cable exit angle of approximately 0 degrees. 
         [0032]      FIG. 2   b  is a side view  201  of a back shell  102  employing a tie wrap  204  to maintain a cable exit angle of approximately 45 degrees, in accordance with an embodiment of the present invention. Cable  202  is held in place via tie wrap  204 , which extends around cable  202  and through either one or both elongated hole  110   b,c  (not shown). 
         [0033]      FIG. 2   c  is a side view  203  of a back shell  102  employing a tie wrap  204  to maintain a cable exit angle of approximately 90 degrees, in accordance with an embodiment of the present invention. Cable  202  is held in place via tie wrap  204 , which extends around cable  202  and through elongated hole  110   d  (not shown). 
         [0034]      FIG. 3   a  is an isometric view  300  of a back shell  302  employing dual split pins  316  and a retaining collar  314 , to maintain a cable exit angle of approximately 0 degrees, in accordance with an embodiment of the present invention. Back shell  302  comprises a cylindrically shaped forward section  304 , which supports transitional element  308  via connecting element  306 . Transitional element  308  has a number of “elongated” holes  310  fashioned therein. These elongated holes  310  provide attachment points for a cable retaining device  312 , which provides strain relief and fixes the direction of the wire cable exiting the back shell. The cable retaining device  312  has a pair of elongated pins  316 , matching the shape of the elongated holes  310 , for fastening the cable retaining device  312  to transitional element  308 . The pins  316  are split, having a slot fashioned in the center of the pins. A retaining collar  314  is placed over the ends of pins  316  to ensure a firm connection between cable retaining device  312  and transitional element  308 . 
         [0035]      FIG. 3   b  is an isometric view  301  of a back shell  302  employing dual split pins and a retaining collar  314 , to maintain a cable exit angle of approximately 45 degrees, in accordance with an embodiment of the present invention. Elongated holes  310   a ,  310   c  are unused in this configuration. 
         [0036]      FIG. 3   c  is an isometric view  303  of a back shell  302  employing dual split pins and a retaining collar  314 , to maintain a cable exit angle of approximately 90 degrees, in accordance with an embodiment of the present invention. Elongated holes  310   a ,  310   b  are unused in this configuration. 
         [0037]      FIG. 3   d  is an isometric exploded assembly view  305  of the back shell  302  of  FIG. 3   b , in accordance with an embodiment of the present invention. In this exploded view, the shape of pins  316  is clearly illustrated. Pins  316  have barbed ends that lock with engagement lands formed within locking collar  314 .  FIG. 3   e  is an isometric, partial cross sectional view  307  of the back shell of  FIG. 3   b . This view illustrates a cut away view of pins  316  engaged with locking collar  314 . The locking collar  314  assures a rigid mating of the cable retaining device  312  to the back shell  302 , but is also designed to be removable in the field, allowing different cable exit angles to be selected by technicians building the wiring systems in-situ, or by cable harness builders assembling a wiring system with jigs. 
         [0038]    Cable retaining device  312  is illustrated as tubular structure having a continuous wall for simplicity. As is well known to those skilled in the art, cable retaining devices may have many other shapes and forms. Each of these may be provided with pins  316  for attachment to the back shell. For example, the tubular section may split in two halves or be hinged (not shown) to allow easy insertion of the cable. Clamps or cable ties may be used to retain the cable. In other embodiments, only a portion of the tubular wall is attached to pins  316 , providing a curved plate (not shown) to which the cable is attached using cable ties or tie wraps. Flexible electrical shielding (not shown) may also be added between forward section  310  cable retainer  312 . This shielding will allow the cable retainer to be mounted for various exit angles while maintaining electrical shield integrity of the back shell assembly. 
         [0039]      FIG. 3   f  is a side view  309  of the back shells  302  of  FIGS. 3   a - 3   e , in accordance with an embodiment of the present invention. Transitional element  308  is cross hatched for clarification of its geometric boundaries and properties. Cylindrically shaped forward section  304  defines an axis of symmetry  322  through the center of the back shell  302 . Transitional element  308  is bounded by two orthogonal edges  318  and  320 . Edge  320  is parallel to axis  322 . Edge  318  is orthogonal to edge  320  (and axis  322 ), and provides the connection interface to connecting element  306 . Angle  326 , defined by axis  324 , resides within the angle formed by the intersection of edges  318  and  320 , and ranges from 0 to 90 degrees. Preferably, angle  326  bisects the angle between the angle formed by the intersection of edges  318  and  320 , and is approximately 45 degrees. Elongated hole pairs  310   a - 310   c  are fashioned within transitional element  318 . Elongated hole pair  310   a  are placed with their longest dimension parallel to edge  320  and axis  322 . Elongated hole pair  310   c  have their longest dimension parallel to edge  318 , or perpendicular to edge  320  and axis  322 . Elongated hole pair  310   b  are oriented with their longest dimension parallel to axis  324 .  FIG. 3   h  is an expanded side view  311  of the elongated holes  310  of  FIG. 3   f . The length  330  of hole  310  is greater than the width, with axis  328  is parallel to the direction of the longest dimension. 
         [0040]      FIG. 4   a  is an isometric view  400  of a back shell  402  employing dual cylindrical pins  416  and a retaining collar  414 , to maintain a cable exit angle of approximately 45 degrees, in accordance with an embodiment of the present invention. Back shell  402  comprises a cylindrically shaped forward section  404 , which supports transitional element  408  via connecting element  406 . Transitional element  408  has a number of circular shaped holes  410  fashioned therein. These holes  410  provide attachment points for a cable retaining device  412 , which provides strain relief and fixes the direction of the wire cable exiting the back shell. The cable retaining device  412  has a pair of circular shaped pins  416 , matching the shape of the holes  410 , for fastening the cable retaining device  412  to transitional element  408 . A retaining collar  414  is placed over the ends of pins  416  to ensure a firm connection between cable retaining device  412  and transitional element  408 . 
         [0041]      FIG. 4   b  is an isometric view  401  of a back shell  402  employing dual cylindrical pins  416  and a retaining collar  414 , to maintain a cable exit angle of approximately 0 degrees, in accordance with an embodiment of the present invention. 
         [0042]      FIG. 4   c  is an isometric view  403  of a back shell  402  employing dual cylindrical pins  416  and a retaining collar  414 , to maintain a cable exit angle of approximately 90 degrees, in accordance with an embodiment of the present invention. 
         [0043]    The present invention is not limited by the previous embodiments heretofore described. Rather, the scope of the present invention is to be defined by these descriptions taken together with the attached claims and their equivalents.