Patent Publication Number: US-9425541-B2

Title: High power electrical connector

Description:
This application claims the benefit of U.S. Provisional Application Ser. No. 61/620,663 filed on Apr. 5, 2012, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention field of connectors, more specifically to the field of connectors suitable for delivery of high power. 
     BACKGROUND OF THE INVENTION 
       FIG. 1  illustrates a schematic of a typical connector configuration. Relatively large gauge cables (e.g., 6 gauge and larger) are coupled to a connector and for electric vehicles the connector can be used to electrically connect the wires in an engine/motor compartment with wires on the opposite side of the dash panel. Convention connectors have suffered from a number of issues. On the one hand, the cables need to provide relatively large current—in the range of 80 to 200 amps (or more) along with the possibility of high voltages (200 Volts or more). This tends to require a cable with a large gauge conductor with good insulation that makes the cable relatively difficult to handle during assembly and repair of the vehicle. This issue can be further complicated by the fact that two separate cables can be connected to the connector. Existing designs, because they need a reliable connection, don&#39;t allow the cables to rotate independently, which makes assembly and use of such cables more challenging. The cables tend to be shielded so as to help manage EMI but because of the high currents (often with sudden spikes in current) provided on the conductors, the shielding can end up carrying a substantial current as well (potentially in the range of 20 to 80 amps). Consequentially, further improvements to the design of high power electrical connectors would be appreciated by certain individuals. 
     SUMMARY OF THE INVENTION 
     A high power electrical connector is provided herein which provides improvements to existing high power electrical connectors and which includes embodiments that overcome certain of the disadvantages presented by the prior art. The high power electrical connector is provided for transmitting electrical signals from a pair of cables, such as bipolar (BP) cables, to an associated member, such as a dash panel. The high power electrical connector includes an insulative housing and a pair of contact path assemblies therethrough for transmission of the electrical signals. The cables can be rotated relative to the housing and rotated relative to each other via the contact path assemblies. Ground path assemblies are also provided for grounding the cables. The cables are rotatable relative to a portion of each ground path assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The organization and manner of the structure and operation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, wherein like reference numerals identify like elements in which: 
         FIG. 1  is a side elevational view of a prior art connector configuration; 
         FIG. 2  is a side elevational view of an embodiment of a high power electrical connector; 
         FIG. 3  is a front perspective view of the embodiment depicted in  FIG. 2 ; 
         FIG. 4  is a rear perspective view of the embodiment depicted in  FIG. 2 ; 
         FIG. 5  is an partially exploded rear perspective view of the embodiment depicted in  FIG. 2 ; 
         FIG. 6  is a simplified, partially exploded front perspective view of the housings of the embodiment depicted in  FIG. 2 ; 
         FIG. 7  is another rear perspective view of the embodiment depicted in  FIG. 6 ; 
         FIG. 8  is a front elevational view of an embodiment of a first housing; 
         FIG. 9  is a front elevational view of an embodiment of a second housing; 
         FIG. 10  is an partial, exploded perspective view of components of the embodiment depicted in  FIG. 2 ; 
         FIG. 11  is an cross-sectional view of embodiment depicted in  FIG. 3 , taken along line  10 - 10 ; 
         FIG. 12  is an enlarged cross-sectional view of the embodiment depicted in  FIG. 11 ; 
         FIG. 13  is another enlarged cross-sectional view of the embodiment depicted in  FIG. 11 ; and 
         FIG. 14  is an enlarged partial cross-sectional view of the embodiment depicted in  FIG. 11  with the first housing part omitted for purposes of clarity. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
     While the invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, a specific embodiment with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that as illustrated and described herein. Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity. While the terms upper, lower and the like are used herein, these terms are used for ease in describing the invention and do not denote a particular required orientation for use of the invention. 
     The embodiments discussed below address certain issues that Applicants have determined exist in existing designs. For example, in certain applications it would be beneficial to allow the two cables to rotate independently from each other and from the connector so that the handling of the connector could be improved but existing designs don&#39;t offer this functionality. In addition, for certain applications it would be beneficial to allow the current on the two shields to cancel out in a manner that reduces the impedance between the two shields. Certain features of the described embodiments can help address these issues. Naturally, features can be removed from a connector if the additional cost of the feature outweighs its usefulness in a particular application. Thus, various levels of connectors with various levels of features are possible. 
     Turning to the figures, a high power electrical connector  20  includes a housing formed from a first housing part  22  which mates to a second housing part  24 . A pair of contact path assemblies  26  and a pair of ground path assemblies  28  and a ground plate  30  are mounted to the housing parts  22 ,  24 . The combination of two ground path assemblies  28  and the ground plate  30  define a ground path connection  28   a  (what could be referred to as down and back along two ground path assemblies) between two conductive shields  38  that are being used to provide signals and/or power. The contact path assemblies  26  provides paths for electrical signals (e.g., power) to travel from a pair of cables  32  to which the contact path assemblies  26  are respectively attached through the housing parts  22 ,  24  to an associated member (not shown) to which the contact path assemblies  26  are attached. The contact path assemblies  26  and the ground path assemblies  28  are electrically isolated from each other. The cables  32  (which can be bipolar cables) can rotate relative to the housing part  22 ,  24  and relative to each other as a result of the structure of the contact path assemblies  26  as described herein. The electrical connector  20  is suitable for electrically connecting to larger gauges of conductors (such as gauges greater than 6 gauge). The ground path assemblies  28  and ground plate  30  provide a ground path to ground the cables  32  to an associated dash panel  34 . The electrical connector  20  can carry high amounts of voltage and current, for example 200 to 400 amps. 
     The use of two cables to provide power is known in the art and this is sometimes referred to bipolar (BP) cables. The cables  32  are elongate and each includes an inner conductive conductor  42  that is configured to carry a high current load, an insulative sheath  40  surrounding the inner conductor  42 , a conductive shield  38  surrounding the insulative sheath  40 , and an outer insulative skin  36 . The outer insulative skin  36  can be cut away to expose the conductive shield  38 , as is known in the art, for grounding the cable  32 . As is known, high current cable cables  32  are stiff heavy cables which can make repairs to the cable (or the components the cables are connected to) challenging. Therefore, allowing the cables  32  to rotate relative to the housing parts  22 ,  24  and to rotate relative to each other has been determined to aid in preventing damage to the cables  32  and to improve assembly flexibility and ease of use. 
     The first housing part  22  is formed of an insulative material and is preferably integrally formed. The first housing part  22  has a generally elliptical-shaped side wall  44  formed from an upper portion, a lower portion and side portions connecting the upper and lower portions. The side wall  44  defines a front end  46  and a rear end  48 . The upper and lower portions are generally planar. The side portions are generally arcuate. A front wall  50  is provided at the front end  46  of the side wall  44  and a first pair of cylindrical extensions  52  extend from a front side of the front wall  50  and each defines a cylindrical passageway  54  therethrough. A second pair of cylindrical extensions  56  extend from a rear side of the front wall  50  and each defines a cylindrical passageway  58  therethrough. The passageways  54  and  58  align with each other, and apertures are formed through the front wall  50  to allow communication between the passageways  54  and  58 , thereby forming central passageways  54 / 58 . The extensions  56  preferably do not extend past the rear end  48  of the side wall  44 . The wall forming the extensions  56  may be slotted as shown. A second pair of cylindrical extensions  60  extend from the rear side of the front wall  50 . The cylindrical extensions  60  surrounds, and is spaced from, the respective first cylindrical extension  56 . A plurality of spaced apart slots  62  are provided around each first cylindrical extension  56 . 
     The second housing part  24  is formed of an insulative material and is preferably integrally formed. The second housing part  24  includes a plate  64  from which a generally elliptical-shaped side wall  66  extends. The side wall  66  is the same shape as the side wall  44  of the first housing part  22 , except that the side wall  66  is smaller so that it fits within the side wall  44  when the housing parts  22 ,  24  are mated together. Accordingly, the side wall  66  defines a front end  70  and a rear end  72 . The side wall  66  is formed from an upper portion, a lower portion and side portions connecting the upper and lower portions. The upper and lower portions are generally planar. The side portions are generally arcuate. A pair of spaced apart cylindrical extensions  74  extend from a front side of the plate  64  and are provided within the side wall  66 . Each cylindrical extension  74  has a cylindrical passageway  76  defined therein. A front end of each cylindrical extension  74  preferably does not extend past a front end of the side wall  66 . A pair of cylindrical extensions  78  extend from a rear side of the plate  64 . A rear wall  80 ,  80   a  closes the rear end of each cylindrical extensions  78 , with the exception of an elliptical shaped aperture  82  provided at the center thereof. The aperture  82  has planar top and bottom surfaces and arcuate side walls. An elongated passageway  84  extends through the respective cylindrical extensions  78  and is in communication with the respective aperture  82 . A bar  86  extends across each aperture  82  from the planar top surface to the planar bottom surface. Apertures are formed through the plate  64  to allow communication between the passageways  76 . Respective passageways  76 ,  78  align with each other and with the respective aperture  82  to form a central passageway  76 / 78 / 82 . Arcuate slots  88  are provided through the plate  64  and are formed around each extension  78 . 
     The rear surface of the plate  64  has a generally rectangular recess  90  therein and the extensions  78  extend outwardly from the recess  90 . A groove  92  is provided in the rear surface of the plate  64  and extends around the perimeter of the recess  90  and is spaced therefrom. An elastomeric seal  94  seats within the groove  92  for sealing the second housing part  24  to the dash panel  34 . A plurality of mounting apertures  96  are provided between the groove  92  and the perimeter of the plate  64 . Fasteners (not shown) are mounted in the mounting apertures  96  for mounting the second housing part  24  to the dash panel  34 . 
     The side wall  66  of the second housing part  24  seats within the side wall  44  of the first housing part  22  when the housing parts  22 ,  24  are assembled together. Respective extension  56  seat within associated extension  74 . A seal member  98  is provided between the extension  60  and the side wall  66 . The housing parts  22 ,  24  are suitably secured to each other such as by snap-fit lock features/tongue and groove and the like, which are known in the art. 
     The contact path assemblies  26  can be identical and therefore only one of the contact path assemblies  26  is described. The contact path assembly  26  includes a conductive inner conductor  100  which is mounted in the first housing part  22  and which is attached to the inner conductor  42  of the cable  32 , a conductive contact  102  which is mounted in the second housing part  24  and which is connected to the conductor  100 , and a conductive c-clip  104  which connects the conductor  100  to the contact  102 . The conductor  100  and the contact  102  form an electrical path through the housings  22 ,  24 . The conductor  100  is rotatably attached to the contact  102 . As a result, the conductor  100  and the cable  32  are rotatable relative to the housing parts  22 ,  24 . 
     The conductor  100  is formed from a first cylindrical wall  104 , a second cylindrical wall  106  and a central wall  108  between the walls  104 ,  106 . The first wall  104  and the central wall  108  define a bind bore  110  therein; the second wall  106  and the central wall  108  define a bind bore  112  therein. A flange  114  extends outwardly from the central wall  108 . The first wall  104  has a front end which flares outwardly. The second wall  106  has four equi-distantly spaced slots which extend from the rear end toward the central wall  108  to define a plurality of legs  116  which can be compressed toward each other. The rear end of the second wall  106  flares outwardly. The conductor  100  seats within the central passageway  54 / 58  of the first housing part  22  and the legs  116  seat within the extension  56 . 
     The contact  102  has a front portion  118  which is cylindrical and a rear portion  120  which forms a flat blade. An aperture  122  is provided through the rear portion  120  proximate to the front end thereof. The contact  102  is mounted in the second housing part  24  and such that the front portion  118  seats within the passageway  76  in the extension  74 , the rear portion  120  seats within the passageway  84  in the extension  78  and extends outwardly from the aperture  82 . The bar  86  extends through the aperture  122 . As a result of this structure, the contact  102  cannot rotate relative to the second housing part  24 . 
     The front portion  104  of the conductor  100  seats over the exposed portion of the inner conductor  42  of the cable  32 . The front portion  104  of the inner conductor  100  is crimped to the inner conductor  42  to electrically connect the inner conductor  100  to the inner conductor  42 . 
     The rear portion  106  of the conductor  100  seats over the cylindrical front portion  118  of the contact  102 . The C-clip  104  engages over the rear portion  106  of the conductor  100  to cause the legs  116  to compress and engage with the cylindrical front portion  118  of the contact  102 . The c-clip  104  provides sufficient compressive force to cause the electrical connection, however, the c-clip  104  does not provide such a compressive force that prevents rotation between the conductor  100  and the contact  102 . 
     The ground path assemblies  28  are identical and therefore only one of the ground path assemblies  28  is described. The ground path assembly  28  includes a conductive ferrule  124 , a conductive cap  126 , a sleeve formed from an inner conductive sleeve part  128  and an outer conductive sleeve part  132 , and a metal C-clip  130 . 
     The ferrule  124  has a cylindrical side wall  134  having a front end and a rear end, a cylindrical passageway  136  therethrough, and a circular flange  138  extending outwardly from the front end of the side wall  134 . Spaced apart slots  140  extend through the flange  138  and extend a predetermined distance along the side wall  134 . Spaced apart protrusions  142  extend from the exterior surface of the side wall  134  and respectively align with the slots  140 , but are spaced therefrom. 
     The conductive cap  126  has a cylindrical side wall  144  having a front end and a rear end and a cylindrical passageway  146  therethrough. A rear wall  148  closes the rear end of side wall  144  and a circular aperture  150  through the rear wall  148  is in communication with the passageway  146 . A pair of diametrically opposed tabs  152  is defined at the front end of the side wall  144  and the tabs  152  are formed by slots through the side wall  144 . 
     The sleeve part  128  is formed from a cylindrical side wall  154  having a front end and a rear end and a cylindrical passageway  156  therethrough. A pair of diametrically opposed slots  158  extend from the rear end of the sleeve part  128  forwardly a predetermined distance. A plurality of spaced apart tabs  160  are punched from the sleeve part  128  and extend outwardly therefrom. The tabs  160  are provided proximate to, but spaced from, the rear end of the sleeve part  128 . A plurality of tabs  162  are punched from the side wall  154  and are proximate to the front end of the slots  158 . A pair of diametrically opposed slots  161  extend from the front end of the sleeve part  128  forwardly a predetermined distance to define legs  161   a  at the front end of the sleeve part  128 . A groove  163  is provided at the front end of the sleeve part  128  for accepting the c-clip  130  therein. The groove  163  is interrupted by the slots  161 . 
     The outer sleeve part  132  is formed from a cylindrical side wall  164  having a front end and a rear end and a cylindrical passageway  166  therethrough. A plurality of spaced apart apertures  168  are provided through the side wall  164 . The outer sleeve part  132  can include a plurality of stepped portions as shown in the drawings. 
     The ground plate  30  is formed from a thin conductive plate which has a pair of circular cutouts  170  therethrough. The circular cutouts  170  define a plurality of flexible fingers  172 . The perimeter of the ground plate  30  has a plurality of flexible fingers  174  extending therefrom. 
     The assembly of the ground path assemblies  28  with the cables  32  can be identical and therefore only one is described. To assemble the ground path assembly  28  with the cable  32 , the shield of the cable  32  is first pulled back to wrap a portion of the shield  38  backwardly over the remainder of the cable  32  and to form a bend in the shield  38 . 
     The cable  32  extends through the cylindrical passageway  136  in the ferrule  124  and the ferrule  124  is placed under the wrapped back portion of the shield  38 . Alternatively, the ferrule  124  can first be seated on the cable  32  and the portion of the shield  38  wrapped backwardly over the ferrule  124 . As a result, the wrapped back portion of the shield  38  extends forwardly over the exterior surface of the ferrule  124  a predetermined distance. 
     The cable  32  extends through the aperture  150  in the cap  126  such the wall forming the aperture  150  abuts against the insulative sheath  40  of the cable  32 , the rear wall  148  of the cap  126  abuts against the bend in the wrapped shield  38  and the side wall  144  of the cap  126  seats over the wrapped back portion of the shield  38 . The front end of the cap  126  abuts against the flange  138  of the ferrule  124 . The slots  140  and protrusions  142  on the ferrule  124  aid in attaching the ferrule  124  to the cable  32 . The tabs  152  on the cap  126  aid in attaching the cap  126  to the ferrule  124 . The connected ferrule  124 , cable  32  and cap  126  seat within the extension  52  of the first housing part  22 . As such, the wrapped back portion of the shield  38  of the cable  32  is sandwiched between the interior surface of the side wall  144  of the cap  126  and the exterior surface of the side wall  134  of the ferrule  124 . 
     The forward end of the sleeve part  128  seats over the side wall  144  of the cap  126 . The c-clip  130  seats within the groove  163  and the legs  161   a  of the sleeve part  128  compress inwardly to attach sleeve part  128  to the side wall  144  of the cap  126 . The cap  126  can rotate relative to the sleeve part  128 . The c-clip  130  provides sufficient compressive force to cause the electrical connection between the sleeve part  128  and the cap  126 , however, the c-clip  130  does not provide such a compressive force that prevents rotation between the sleeve part  128  and the cap  126 . Since the c-clip  130  is provided, a softer material can be used for the sleeve part  128  while ensuring a reliable electrical connection between the sleeve part  128  and the cap  126 . The sleeve part  128  seats partially in the extension  52 , extends through the aperture in the front wall  50  of the first housing part  22  and seats through the slots  62  surrounding the extension  60 . The first housing part  22  fills the slots  158  in the sleeve part  128  to connect the sleeve part  128  to the first housing part  22 . The tabs  162  engage with the first housing part  22 . 
     The sleeve is formed by seating the front end of the outer sleeve part  132  over the rear end of the inner sleeve part  128 . The outer sleeve part  132  seats over and engages with the tabs  160  on the inner sleeve part  128 . The engagement of the tabs  160  with the internal surface of the outer sleeve part  132  ensures a reliable electrical connection between the outer sleeve part  132  and the inner sleeve part  128 . The outer sleeve part  132  extends through slots  88  and encircles the extension  78  of the second housing part  24 . The second housing part  24  extends through the apertures  166  in the outer sleeve part  132  to prevent the removal of the outer sleeve part  132  from the second housing part  24 . 
     The ground plate  30  seats within the recess  90  of the second housing part  24  and generally conforms to the shape of the recess  90 . The plurality of flexible fingers  172  engage with the rear end of the outer sleeve part  132  to provide a reliable electrical connection between the ground plate  30  and the outer sleeve part  132 . The plurality of flexible fingers  174  extend outwardly from the recess  90  for engagement with the dash plate  34  to provide a reliable electrical connection between the ground plate  30  and the dash plate  34 . 
     As a result of this structure, grounding of the cable  32  is provided. The shield  38  is electrically connected to the cap  126 ; the cap  126  is electrically connected to the inner sleeve part  128 ; the inner sleeve part  128  is electrically connected to the outer sleeve part  132 ; the outer sleeve part  132  is electrically connected to the ground plate  30 . The ground plate  30  is grounded to the dash panel  32 . 
     A pair of end cap and seal assemblies  176  which includes an end cap  178  and a seal  180  provides waterproof seals with the respective cables  32  at the front end of the first housing part  22 . The end cap and seal assemblies  176  are identical and their assembly with the first housing part  22  and the cables  32  are identical, and therefore, only a single end cap and seal assembly  176  and its assembly is described. The end cap and seal assembly  176  which includes an end cap  178  and an elastomeric seal  180 . The end cap  178  is formed from a cylindrical side wall  182  having a front end and a rear end and a cylindrical passageway  184  therethrough. A front wall  186  closes the front end of the side wall  182  and has a circular aperture  188  provided therethrough which is in communication with the passageway  184 . A pair of slots  190  are provided through the side wall  182  and are diametrically opposed to each other. 
     The seal  180  seats within the end cap  178  and surrounds the cable  32 . The seal  180  is formed of an elastomeric material with a body  190  having a central passageway  192  therethrough. The exterior surface of the body  190  has corrugations thereon and the internal surface forming the central passageway  192  has corrugations thereon. The cable  32  seats through the central passageway  192 . The front end of the ferrule  124  abuts against the rear end of the seal  180 . The seal  180  engages the interior surface of the extension  52  of the first housing part  22 . The seal  180  has an outer diameter which is slightly larger than the internal diameter of the extension  52 . As a result, the seal  180  is slightly compressed within the extension  52  to form a watertight seal. The end cap  178  seats over the front end of the extension  52  and is attached thereto by the slots  190  engaging with protrusions  194  on the extension  52 . This prevents the seal  180  from disengaging from the cylindrical extension. 
     As a result of this structure, each cable  32 , the conductor  100 , the contact  102 , the ferrule  124  and the cap  126  are affixed together and are mounted in the housing parts  22 ,  24 . The cable  32 , the conductor  100 , the ferrule  124  and the cap  126 , are non-rotatably affixed together. Since the contact  102  and the conductor  100  are rotatably connected to each other, and since the sleeve part  128  and the cap  126  are rotatably connected to each other, the affixed cable  32 /conductor  100 /cap  126 /ferrule  124  combination can rotate relative to the contact  102 , and thus can rotate relative to the housing parts  22 ,  24  when a user desires to rotate the cable  32 . The seal  180  may rotate with this assembly, or may stay stationary with the second housing part  24 . The two cables  32  can be rotated separately from each other if desired. 
     The structure of the electrical connector  20  provides a very low resistance, preferably between 1 and 100 milliohms (mΩ) and more preferably below 30 mΩ, between the conductive shields  38  of the two cables (e.g., along the ground path connection  28   a ). Naturally, improvements in impedance must be balanced with ease of assembly and cost (as further reductions in impedance generally require more expensive materials and higher contact forces and must be balanced with the resultant increased insertion forces and higher costs that will eventually limit the ability to further reduce impedance in a practical manner). Providing a connector with a resistance of about 1 mΩ or less might not be desirable from a cost and ease of use standpoint. The depicted design has been tested, for example, and can provide a resistance of about 9-10 mΩ. Therefore, for many applications aiming for a resistance of between 5 and 50 mΩ may be a more desirable target. Consequentially, in certain embodiments the ground path connection  28   a  can be configured so that the impedance can be low (e.g., less than 100 mΩ) for currents less than 80 amps. 
     While a preferred embodiment of the present invention is shown and described, it is envisioned that those skilled in the art may devise various modifications of the present invention without departing from the spirit and scope of the appended claims.