Abstract:
A sealed electrical receptacle connector, either male or female, includes, in combination, a bushing and a shell threadably coupled together in an end-to-end manner. The bushing is adapted to receive a cable having plural conductors arranged in a spaced manner and separated from another along their respective lengths by an elongated nonconductive insert having plural radi ally extending spaced members, each disposed between a pair of adjacent conductors. A split washer is disposed between and in abutting contact with adjacent inner end portions of the receptacle and the shell and includes a slot extending therethrough. The split washer facilitates receptacle connector assembly and its slot is adapted to receive the plural conductors and an elongated axial strength member, such as a multi-strand steel cable, disposed within and along the length of the nonconductive insert to provide the receptacle connector and cable combination with high strength.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to electrical receptacle connectors, and is particularly directed to an electrical receptacle connector having an internal structural member disposed within an electrical cable coupled to the connector for providing the cable and connector combination with great strength. 
       BACKGROUND OF THE INVENTION 
       [0002]    An electrical receptacle connector is a fitting connected to an electrical cable and adapted to receive a plug. The cable may carry electric power or may include one or more conductors carrying electrical signals. Sometimes the receptacle connector is attached to an electrical panel member. When employed in a harsh environment, large forces may be applied to the receptacle connector which may result in loosening or separation of the cable from the receptacle connector and loss of power or electrical signals. To deal with these large forces, some connectors are provided with high strength materials. One form that these high strength materials take is known as Kevlar. Kevlar as a para-aramid synthetic fiber having high strength. Kevlar is typically spun into ropes or fabric sheets, or it may be used as an ingredient in composite material components. Kevlar exhibits a high tensile strength-to-weight ratio and is said to be five times stronger than steel on an equal weight basis. However, on a space, or volume, basis, a substantially greater amount of Kevlar is required to provide the same strength as steel. Thus, where space is at a premium, such as in the area of electrical connectors and components, Kevlar&#39;s applications are somewhat limited. In addition, because Kevlar typically is comprised of a large number of individual strands of different lengths, the cumulative effect of all of the strands is not realized along the entire length of an elongated Kevlar member such as an electrical cable and connector assembly and the strength exhibited by Kevlar in this environment is limited. In addition, Kevlar strands are typically secured to another member by tying which is impractical in the small dimension environment of electrical connectors. 
         [0003]    The present invention is intended to provide a high strength electrical receptacle connector capable of operating in harsh duty environments where tension values as high as  300  pounds may be encountered. 
       SUMMARY OF THE INVENTION 
       [0004]    Accordingly, it is an object of the present invention to provide a high strength, compact electrical receptacle connector which is easily connected in a sealed manner and disconnected and may be either female or male in configuration. 
         [0005]    It is another object of the present invention to provide an electrical receptacle connector adapted for use with multiple conductors in a single shielded cable which includes an elongated nonconductive insert for maintaining the conductors in fixed, spaced relation and for providing physical and electrical isolation between adjacent conductors within the receptacle connector. 
         [0006]    A further object of the present invention is to provide a split washer in an electrical receptacle connector which is securely coupled to a high strength steel cable to provide the receptacle connector with high strength and which allows the receptacle connector to be easily assembled. 
         [0007]    A still further object of the present invention is to provide an electrical receptacle connector comprised of an end-to-end threadably coupled bushing and shell combination and which is connected to a cable having plural conductors and a steel cable to provide high strength, wherein tightening of the threadably coupled bushing and shell places the steel cable under increased tension while simultaneously introducing slack in the electrical conductors. 
         [0008]    The present invention contemplates an electrical receptacle connector adapted to receive an electrical cable having plural conductors, the electrical receptacle connector comprising: a bushing adapted to receive the electrical cable and having a first threaded end portion; a shell adapted to receive the electrical cable and having a second threaded end portion coupled to the first threaded end portion of the bushing; an elongated, thin strength member disposed in and extending along a portion of the length of the electrical cable; and a split washer connected to the strength member and having an open inner portion and a partially circular peripheral portion, wherein the plural conductors are disposed in and extend through the open inner portion of the split washer and the partially circular peripheral portion of the split washer is disposed in contact with the first threaded end portion of the bushing, and wherein tightening of the coupling between the bushing&#39;s first threaded end portion and the shell&#39;s second threaded end portion urges the split washer into tight fitting engagement with the shell applying increased tension upon the strength member while removing tension from the plural conductors. 
         [0009]    The present invention further contemplates a multi-conductor electrical cable and receptacle connector arrangement comprising: a bushing adapted to receive the electrical cable and having a first threaded end portion; a shell adapted to receive the electrical cable and having a second threaded end portion coupled to the first threaded end portion of the bushing; an elongated, thin strength member disposed in and extending along a portion of the length of the electrical cable; a retaining member having an open inner portion and a partially circular peripheral portion, wherein the plural conductors and the strength member are disposed in and extend through the open inner portion of the retaining member and the partially circular peripheral portion of the retaining member is disposed in contact with the first threaded end portion of the bushing for increasing the strength of the electrical cable receptacle and connector arrangement; and an elongated centering and isolating member disposed within and along at least a portion of the length of the cable, wherein the centering and isolating member is disposed about the strength member and intermediate adjacent conductors for centering the strength member within the cable and isolating the conductors from the strength member while maintaining the conductors in equally spaced relation from one another. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements throughout the various figures, in which: 
           [0011]      FIG. 1  is a side elevation view of a harsh duty receptacle connector in accordance with the principles of the present invention; 
           [0012]      FIG. 2  is a longitudinal sectional view of the inventive harsh duty receptacle connector; 
           [0013]      FIG. 3  is an exploded perspective view of a portion of the inventive harsh duty receptacle connector; 
           [0014]      FIG. 4  is another exploded perspective view of the inventive harsh duty receptacle connector illustrating additional details of the invention; 
           [0015]      FIG. 5  is a sectional view illustrating internal details of the inventive harsh duty receptacle connector; and 
           [0016]      FIG. 6  is a sectional view of a multi-conductor cable with which the harsh duty receptacle connector of the present invention is adapted for use. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Referring to  FIG. 1 , there is shown a side elevation view of a harsh duty receptacle connector  10  in accordance with the principles of the present invention. A longitudinal sectional view of the inventive receptacle connector  10  is shown in  FIG. 2 .  FIGS. 3 and 4  are exploded perspective views illustrating additional details of the inventive receptacle connector  10 . 
         [0018]    Receptacle connector  10  includes a receptacle bushing  12  and a receptacle shell  14 . Bushing  12  and shell  14  are generally cylindrical in shape, are preferably comprised of a high strength metal such as steel, and include respective center slots extending therethrough for receiving a shielded electrical cable  18 . 
         [0019]    Cable  18  includes plural spaced electrical conductors  16   a - 16   d  extending along the length thereof. Disposed within cable  18  and between the individual conductors  16   a - 16   d  is an elongated, nonconductive centering/isolating member  46  preferably comprised of a non-rigid plastic as shown in the sectional view of  FIG. 6 . Centering/isolating member  46  extends along the length of cable  18  and includes four spaced members  46   a - 46   d,  each extending radially outward from a center portion  46   e  of the center/isolating member. Each of the four radially extending spaced members  46   a - 46   d  is preferably integrally formed with the center portion  46   e  of the centering/isolating member  46 . First spaced member  46   a  is disposed between first and second electrical conductors  16   a,    16   b,  while second spaced member  46   b  is disposed between the second and third electrical conductors  16   b,    16   c.  Similarly, the third spaced member  46   c  is disposed between the third and fourth electrical conductors  16   c,    16   d  while the fourth spaced member  46   d  is disposed between the fourth and first electrical conductors  16   d,    16   a.  Adjacent spaced members of centering/isolating member  46  maintain each electrical conductor in fixed position during electrical conductor  18  manufacture and provide electrical isolation between adjacent electrical conductors. 
         [0020]    Extending along the length and disposed within the center portion  46   e  of the centering/isolating member  46  is a strength member  20 , as also shown in  FIG. 6 . Strength member  20  could take on various forms, but in a preferred embodiment is a multi-strand steel aircraft cable which provides high strength for the harsh duty receptacle connector  10  as described in detail below. Centering/isolating member  46  also ensures that high strength member  20  is centered in cable  18  and provides physical isolation of the four conductors  46   a - 46   d  from strength members  20 . 
         [0021]    Receptacle bushing  12  includes an external threaded end portion  12   a  which is adapted for engagement with an internal threaded end portion  14   a  of receptacle shell  14 . Receptacle shell  14  further includes a second outer threaded portion  14   c  and an intermediate enlarged shoulder portion  14   b  disposed between the receptacle shell&#39;s inner threaded portion  14   a  and its aforementioned outer threaded portion. The outer periphery of the receptacle shell&#39;s enlarged shoulder portion  14   b  is provided with plural flat portions  14   d  as shown in  FIG. 1  to facilitate engagement of the receptacle shell  14  by a wrench (not shown) for attaching the receptacle shell to a nut  28  for securely mounting the inventive receptacle connector  10  to a structural member such as flat panel  27  as shown in  FIG. 2 . The outer threaded portion  14   c  of receptacle shell  14  is also provided with plural spaced flat portions  14   e,  also as shown in  FIG. 1 , which are received by a matched flat portion in a cut-out (not shown) within the panel  27  to eliminate rotation of shell  14  during installation of nut  28 . Finally, the outer peripheral surface of receptacle bushing  12  is also provided with plural spaced flat portions  12   c  as shown in  FIGS. 3 ,  4  and  5  to facilitate manipulating the receptacle bushing by means of a tool such as a wrench. 
         [0022]    Adjacent ends of each of the first through fourth conductors  16   a - 16   d  are adapted to receive respective electrical contacts  26   a - 26   d  as shown in  FIG. 3 . Each of the electrical contacts  26   a - 26   d  is adapted for insertion through a respective slot within a cylindrical insulator  29 . Cylindrical insulator  29 , which includes four slots  38  as shown in  FIG. 3 , is inserted into a circular slot extending through receptacle shell  14 . An end  29   b  of the slotted cylindrical insulator  29  and the ends of the four electrical contacts  26   a - 26   d  extend outward from the end of receptacle shell  14 . The four electrical contacts  26   a - 26   d  are adapted for mating electrical connection to respective electrical contacts of a complementary connector, which is not shown in the figures for simplicity. In addition, while the four electrical contacts  26   a - 26   d  are shown recessed within one of respective slots  38  in the slotted cylindrical insulator  29  for receiving complementary male contacts, the present invention also contemplates the use of the four electrical contacts in a male, or projecting, configuration for mating electrical engagement with four female contacts in the complementary electrical connector which is not shown in the figures for simplicity. Finally, an elongated slot  29   a  in a lateral portion of cylindrical insulator  29  forms a keyway for permitting mating contact of the distal end of the insulator and its associated four electrical contacts  26   a - 26   d  with a complementary configured connector. 
         [0023]    Receptacle connector  10  further includes a drain wire attachment  30  attached to cable  18  and including a drain wire  30   a  which extends along the length of shielded cable  18 . Drain wire attachment  30  is in electrical contact with receptacle bushing  12  which is maintained at ground potential because receptacle bushing is connected to receptacle shell  14  which is in contact with structural member  27  which is at ground potential. The combination of drain wire attachment  30  and its drain wire  30   a  maintains the cable&#39;s inner conductive sheath at the same potential along the entire length of cable  18  to provide effective electromagnetic interference (EMI) shielding for the cable. A first O-ring  34  is positioned between an inner portion of receptacle shell  14  and structural member  27  in a sealed manner. A small bead  44  of UV potting material is deposited on an outer peripheral surface of insulator  36  so as to form a seal with an inner surface of receptacle shell  14 . 
         [0024]    With the four conductors  16   a - 16   d  disposed within and along the length of cable  18  and maintained in fixed position therein by means of a centering/isolating member  46 , the end of strength member  20 , which is disposed within centering/isolating member, is inserted through a slot  22   a  within a split washer  22 . A stop sleeve  24  comprised of a conductive material such as copper is crimped to the end of strength member  20  for securely attaching the stop sleeve to the strength member as shown in  FIG. 3 . There are various other approaches available for securely attaching a stop member to the end of the strength member  20  to prevent disconnection of the strength member from split washer  22 , with the crimping arrangement shown in the figures being the preferred way to securely attach these two components of the receptacle connector  10  of the present invention. 
         [0025]    With cable  18  disposed within and extending through receptacle bushing  12  and with the four conductors  16   a - 16   d  and the strength member  20  extending through an open inner portion  22   c  of split washer  22 , the exterior threaded portion  12   a  of receptacle bushing  12  is positioned in contact with the internal threaded portion  14   a  of receptacle shell  14 . Rotation of one or both of the receptacle bushing  12  and receptacle shell  14  relative to the other results in secure engagement between these two receptacle connector components. During tightening of the threaded engagement between the receptacle bushing  12  and receptacle shell  14 , the outer peripheral portion of split washer  22  is positioned in contact with the end portion  12   b  of receptacle bushing  12  adjacent its exterior threaded portion  12   a  as shown in the sectional view of  FIG. 5 . Continued tightening of the threaded engagement between receptacle bushing  12  and receptacle shell  14  causes tension to be applied to strength member  20 . When the receptacle connector  10  is tightly assembled and in use, this tension is maintained on strength member  20  which removes all tension from the four conductors  16   a - 16   d,  resulting in slack in all of these conductors. The slack in each of the first through fourth conductors  16   a - 16   d  is shown in  FIGS. 2 ,  3  and  4  as bent portions of each of these conductors. This reduces the likelihood of detachment of any of the conductors from its associated end contact upon the application of a large axial force to the receptacle connector  10 . In a preferred embodiment, strength member  20  is in the form of an aircraft cable capable of withstanding an axial tension of 300 pounds. Also in a preferred embodiment, the outer surface of receptacle bushing  12 , and its juncture with cable  18 , is covered with a thin layer of shrink tubing  42 . 
         [0026]    Once the inventive receptacle connector  10  is assembled, an inert semi-rigid potting compound having a high durameter rating is injected via a first slot  32  into the receptacle bushing  12 . The potting compound, which is typically comprised of a polymer such as epoxy or polyurethane, encapsulates and fixes in position and configuration the electrical conductors  16   a - 16   d  therein. A second slot  33  within receptacle bushing  12  allows for the escape of air from the bushing as the potting compound is injected into the bushing. 
         [0027]    While particular embodiments of the present invention have been described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications that fall within the true spirit and scope of the invention. The matters set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.