Abstract:
A duplex electrical connector providing two inbound end apertures to conduct two helically wound armored or metal clad electrical cables through a single hole in an electrical junction box and secure it thereto. The duplex connector includes a housing with spring steel cable retainers at its inbound end to secure the cables and prevent their forceful withdrawal from the box. A spring steel adapter is included at the outbound end of the housing to provide easy snap-in attachment to the box. Two embodiments include an insert for attaching the cable retainers to the housing and a third embodiment includes a housing that accepts the cable retainers without the need for a separate insert.

Description:
This application is a Continuation-In-Part of U.S. Patent Application entitled “Duplex Connector” filed Feb. 23, 2001, application Ser. No. 09/792,185 now U.S. Pat No. 6,355,884 which is a Continuation-In-Part of U.S. Patent Application entitled “Duplex Connector” filed Aug. 13, 1999, application Ser. No. 09/373,427 now U.S. Pat. No. 6,194,661. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to cable terminations and more particularly to duplex or two-wire cable terminations that snap into place and include snap-on cable retainers, neither of which requires twisting for locking. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 6,080,933 issued Jun. 27, 2000 in the name of Thomas J. Gretz for “Snap in Cable Connector”, and herein incorporated by reference in its entirety, describes a locking cable connector composed of three mating pieces that snap together and provide a connector for connecting helically wound armored or metal clad electrical conductors to junction boxes or electrical panels. The first piece of the snap in locking cable connector is a die cast member including at its inner end a smooth outer cylindrical section having an outer diameter with flanges that accommodates a second piece comprising a spring steel adapter. The spring steel adapter is used to secure the connector to a junction box. The third piece is a spring steel locking ring provided to receive a helically wound shielded cable that is inserted into the outer end of the die cast member. The locking ring has outwardly directed tangs that snap into the die cast member and secure it thereto. The locking ring also has inwardly directed tangs to receive the armored cable through its inner bore and restrict its removal by a rearward applied force. The part named “spring steel locking ring” of U.S. Pat. No. 6,080,933 is hereinafter referred to as “spring steel cable retainer” in this disclosure. 
     U.S. Pat. No. 6,194,661 issued Feb. 27, 2001 in the name of Thomas J. Gretz for “Duplex Connector”, and herein incorporated by reference in its entirety, discloses a duplex connector that combines the spring steel locking ring and spring steel adapter of U.S. Pat. No. 6,080,933 with a novel connector to connect two helically wound armored or metal clad electrical conductors to a junction box or an electrical panel through a single access hole or knockout. The duplex connector includes a housing having a generally oval or race track-shaped inbound end and a cylindrical outbound end. The inbound end of the housing is adapted to accept an insert containing two spring steel cable retainers that are analogous to the spring steel locking rings of U.S. Pat. No. &#39;933 with the outbound end adapted to accept a spring steel adapter analogous to the spring steel adapter of U.S. Pat. No. &#39;933. The insert is secured to the housing in U.S. Pat. No. &#39;661 by a screw or similar fastening device. 
     Although the duplex connector of U.S. Pat. No. &#39;661 provides an easy way to connect two conductors through a single access hole in a junction box or panel, it can be improved. A simpler design of the duplex connector of &#39;661 could be created by removing the outward tangs on the cable retainers and replacing the apertures on the insert with a threaded hole sized to accept a set screw. Set screws could then be inserted to secure the spring steel cable retainers to the insert. Another simpler design of both the spring steel cable retainers and the insert would be achieved by forming annular ridges at the inboard end of the insert to hold the cable retainers inside the insert. In this manner the outward tangs on the cable retainers could be eliminated along with the tang apertures on the insert. 
     The duplex connector of the present invention could be made even simpler by modifying the inbound end of the connector housing to hold the cable retainers. Modified in this manner, the insert could be eliminated thereby reducing the number of required parts. 
     SUMMARY OF THE INVENTION 
     The present invention provides several simplified designs of the duplex connector disclosed in U.S. Pat. No. 6,194,661 issued Feb. 27, 2001 to Gretz. U.S. Pat. &#39;661 discloses a duplex connector that combines the spring steel locking ring and spring steel adapter of U.S. Pat. 6,080,933 with a novel connector to connect two helically wound armored or metal clad electrical conductors to a junction box or an electrical panel. The duplex connector includes an insert that is fastened to its inbound end and includes spring steel cable retainers to secure two inbound cables. 
     A first embodiment of the present invention simplifies the design of the duplex connector of U.S. Pat. No. &#39;661 by removing the outward tangs on the cable retainers and replacing the apertures on the insert with a threaded hole sized to accept a set screw. Set screws are then inserted to secure the spring steel cable retainers to the insert. In this manner the machining of the spring steel cable retainers are simplified by eliminating the requirement to form outwardly extending tangs. Machining of the insert is also simplified by eliminating the apertures to accept the tangs of the cable retainers. 
     A second embodiment of the duplex connector simplifies the connector even further by providing annular ridges at the inbound end of the insert to act as a retainer for holding the spring steel cable retainers. The cable retainers are then simply snapped into place within the inbound end of the insert thereby eliminating the need for tangs or set screws to hold them in place. 
     A third and preferred embodiment simplifies the duplex connector of U.S. Pat. No. &#39;661 even further by eliminating the need for an insert. In this embodiment, the inbound end of the connector housing is modified to accept the spring steel cable retainers without the need for an insert. This greatly simplifies the construction of the duplex connector by completely eliminating the need for a separate part. 
     Another simpler design of both the spring steel cable retainers and the insert would be achieved by forming annular ridges at the inboard end of the insert to hold the cable retainers inside the insert. In this manner the outward tangs on the cable retainers could be eliminated along with the tang apertures on the insert. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a blown apart view of a first embodiment of the duplex connector of the present invention in which tangs and tang apertures are eliminated from the cable retainers and insert respectively. 
     FIG. 2 is a blown apart view of a second embodiment of the duplex connector of the present invention in which cable retainers are held in the insert by annular ridges. 
     FIG. 3 is a blown apart view of a third and preferred embodiment of the duplex connector of the present invention in which the insert is eliminated. 
     FIG. 4 is a side view of spring steel cable retainer  20  or  22  of FIG.  3 . 
     FIG. 5 is an end of spring steel retainer  20  or  22  as viewed from forward edge  124  of the retainer shown in FIG.  4 . 
     FIG. 6 is an end view of the inbound end of the housing of the preferred embodiment of FIG.  3 . 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Table of Nomenclature 
               
             
          
           
               
                   
                 Part No. 
                 Part Description 
               
               
                   
                   
               
               
                   
                  10 
                 duplex connector 
               
               
                   
                  12 
                 housing 
               
               
                   
                  14 
                 inbound end (of housing 12) 
               
               
                   
                  15 
                 aperture in outbound end of housing 
               
               
                   
                  16 
                 outbound end (of housing 12) 
               
               
                   
                  17 
                 outer diameter (of outbound end of housing) 
               
               
                   
                  18 
                 inbound end insert 
               
               
                   
                  19 
                 flange (of outbound end of housing) 
               
               
                   
                  20 
                 spring steel cable retainer 
               
               
                   
                  21 
                 flange (of inner portion of outbound end of housing) 
               
               
                   
                  22 
                 spring steel cable retainer 
               
               
                   
                  23 
                 slots (in cable retainers 20, 22) 
               
               
                   
                  24 
                 inbound insert aperture 
               
               
                   
                  25a 
                 annular ridge 
               
               
                   
                  25b 
                 annular ridge 
               
               
                   
                  26 
                 inbound insert aperture 
               
               
                   
                  27 
                 inward cable-gripping tangs (in cable retainers) 
               
               
                   
                  28 
                 spring steel adapter 
               
               
                   
                  29 
                 slot (in spring steel adaptor) 
               
               
                   
                  30 
                 locking screw (to secure inbound end insert) 
               
               
                   
                  31 
                 tangs (on outer circumference of adapter 28) 
               
               
                   
                  32 
                 bushing 
               
               
                   
                  34 
                 peepholes 
               
               
                   
                  36 
                 shoulder portions (of housing) 
               
               
                   
                  38 
                 interior surface (of shoulder portions) 
               
               
                   
                  40 
                 internal volume (of housing) 
               
               
                   
                  42 
                 top wall 
               
               
                   
                  44 
                 bottom wall 
               
               
                   
                  46 
                 insertion end (of insert 18) 
               
               
                   
                  47 
                 threaded hole (for screw 30) 
               
               
                   
                  48 
                 end (of insert 18) 
               
               
                   
                  50 
                 flange (of insert 18) 
               
               
                   
                  52A 
                 outward projecting tang (of cable retainer) 
               
               
                   
                  52B 
                 outward projecting tang (of cable retainer) 
               
               
                   
                  54A 
                 tang aperture (for tang 52a) 
               
               
                   
                  54B 
                 tang aperture (for tang 52b) 
               
               
                   
                  56A 
                 outward projecting tang (of cable retainer) 
               
               
                   
                  56B 
                 outward projecting tang (of cable retainer) 
               
               
                   
                  57A 
                 tang aperture (for tang 56A) 
               
               
                   
                  57B 
                 tang aperture (for tang 56B) 
               
               
                   
                  58 
                 cylindrical body (of bushing) 
               
               
                   
                  60 
                 flange (of bushing) 
               
               
                   
                  70 
                 flange (of housing) 
               
               
                   
                  80 
                 panel 
               
               
                   
                  81 
                 viewing window 
               
               
                   
                  82 
                 projections (from panel) 
               
               
                   
                 108 
                 aperture (in cable retainer) 
               
               
                   
                 110a 
                 inwardly extending tang (of cable retainer) 
               
               
                   
                 110b 
                 inwardly extending tang (of cable retainer) 
               
               
                   
                 110c 
                 inwardly extending tang (of cable retainer) 
               
               
                   
                 118 
                 gap (of cable retainer) 
               
               
                   
                 124 
                 forward edge (of cable retainer) 
               
               
                   
                 126 
                 trailing edge (of cable retainer) 
               
               
                   
                   
               
             
          
         
       
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIG.  1  and FIG. 2, the duplex connector  10  of the first two embodiments of the present invention comprises many of the same components as the duplex connector of U.S. Pat. No. 6,194,661 including a housing  12  having a generally oval or race track-shaped inbound end  14  and a cylindrical outbound end  16 , an inbound end insert  18 , spring steel cable retainers  20  and  22  that insert into a pair of parellel apertures or openings  24  and  26  in the inbound end, spring steel adapter  28  about the outer diameter  17  of cylindrical outbound end  16  and retained by flanges  19  and  21 , locking screw  30 , a bushing  32  inserted into the inner circumference of outbound end  16  and a pair of peepholes  34  that permit viewing of the interior of housing  12  to determine the presence and/or location of cable inserted into housing  12  through insert apertures  24  and  26 . 
     Housing  12 , in addition to previously described generally oval inbound end  14 , peepholes  34 , and cylindrical outbound end  16  incorporating outer diameter  17  and flanges  19  and  21  includes shoulder portions  36  whose interior surfaces  38  are smooth to guide cables inserted through inbound end  14  via insert apertures  24  and  26  toward and through internal volume  40  of cylindrical outbound end  16 . Additionally, housing  12  includes, in at least one of its relatively flat top or bottom walls  42  and  44 , a threaded hole  47  for rotational engagement of screw  30  as described hereinafter. Flange  19  has a slight inward incline to ease insertion of housing  12  into a junction box aperture and to ease the application of spring steel adapter over outer diameter  17 . Flange  21  is of a greater diameter than flange  19  to prevent over insertion of spring steel adapter  28 . 
     In the first two embodiments of the duplex connector shown in FIGS. 1 and 2, insert  18  comprises a binocular shape and has outer dimensions at insertion end  46  that are matched to the inner dimensions of generally oval inbound end  14  of housing  12 . End  48  of insert  18  includes a flange  50  about both insert apertures  24  and  26  that serves as a stop to limit insertion of insert  18  into inbound end  14  of housing  12 . 
     Referring to FIG. 1, the first embodiment of the duplex connector  10  of the present invention includes the spring steel cable retainers  20 ,  22  aligned with the central axis of each of their respective inbound insert apertures  24 ,  26 . The cable retainers  20 ,  22  are each discontinuous at slots  23 . When inserted into insert  18 , the cable retainers  20 ,  22  are compressed until slots  23  become essentially closed and allow them to be inserted into their respective insert aperture  24 ,  26 . A plurality of inwardly directed tangs  27 , one of which is in view in FIG. 1 on each cable retainer  20 ,  22 , are oriented toward the insert  18  and extend into the central core of the retainers  20 ,  22 . The cable retainers  20 ,  22 , after being compressed and inserted into their respective insert apertures  24 ,  26 , snap outwardly and are held in the insert  18  by tightening of the respective set screws  55 A,  55 B. The first embodiment of the present invention thereby reduces the amount of machining required by eliminating the need to form outward tangs in the cable retainers  20 ,  22  and tang accepting apertures in the insert  18 . 
     As shown in FIG. 1, a bushing  32  comprising a cylindrical body  58  having a flange  60  is inserted at the outbound end  16  of the housing  12  to prevent accidental damage to inserted cable (not shown in FIG.  1 ). Bushing  32  is designed to frictionally engage the interior of cylindrical outbound end  16  of housing  12  and is preferably made of a polymeric material that serves to cushion cable inserted into housing  12  and exiting through cylindrical outbound end  16 . 
     As shown in FIG. 1, spring steel adapter  28  includes a slot  29  to permit expansion prior to being fitted over diameter  17 , and includes a plurality of tangs  31  to prevent removal of adapter  28  from the aperture of a junction box (not shown) after installation into such an aperture. A more detailed description of adapter  28  and its operation can be found in U.S. Pat. No. 6,080,933 entitled “Snap In Cable Connector”, assigned to the same assignee as the present invention and incorporated herein by reference. 
     Referring to FIG. 2, the second embodiment of the duplex connector  10  is a simplified design that eliminates the need for tangs or set screws to secure the spring steel cable retainers  20 ,  22  to the insert  18 . In this embodiment, the cable retainers  20 ,  22  are held in place by annular ridges  25 A,  25 B in each respective inbound insert aperture  24 ,  26 . To insert the cable retainers  20 ,  22  in the insert apertures  24 ,  26 , the discontinuous cable retainers  20 ,  22  are each compressed until each slot  23  is minimized. The compressed cable retainers  20 ,  22  are then slipped past the annular ridges  25 A,  25 B into the insert apertures  24 ,  26  and then allowed to relax to their unbiased shape. The cable retainers  20 ,  22  therefore snap outwardly to their larger unbiased diameters and are held in the insert  18  by their respective annular ridges  25 A,  25 B. Peepholes  34  are provided in the top wall  42  of the insert  18  to assist in viewing the wiring after it is installed inside the connector  10 . The second embodiment of the present invention thereby reduces the amount of machining required by eliminating the need to form outward tangs, tang accepting apertures, or set screws to hold the cable retainers  20 ,  22  in place. 
     A blown apart view of the third and preferred embodiment of the duplex connector  10  is depicted in FIG.  3 . The insert, as shown in FIG. 3, has been eliminated and its functionality has been built into the housing  12 . In the duplex connector of U.S. Pat. No. 6,194,661, tang accepting apertures were formed in the insert. In the present embodiment of the duplex connector  10 , the tang accepting apertures  54 A,  54 B,  57 A,  57 B are formed in the inbound end  14  of the housing  12 . As cable retainer  20  is compressed, inserted into inbound insert aperture  24  and then released, outward extending tang  52 A snaps into tang aperture  54 A and outward extending tang  56 A snaps into tang aperture  57 A. Cable retainer  22  is held in a similar manner by tangs  52 B and  56 B and tang apertures  54 B and  57 B. This preferred embodiment of the duplex connector  10  thereby simplifies the design of the connector even further by eliminating the need for a separate insert and housing and including the functionality of the insert in the housing. The inbound end  14  of the housing includes a flange  70  that adds structural rigidity to the housing. 
     The preferred embodiment of the duplex connector shown in FIG. 3 also has an advantage of a larger viewing area for internal connections. A viewing window  81  is provided in the top wall  42  of the housing  12 . A snap-fit panel  80  is provided with the duplex connector  10  and snapped into place in the viewing window  81 . Projections  82  on the panel provide a means for panel  80  to snap fit into the viewing window  81 . The panel  80  may later be removed if desired for later viewing the cables within the connector  10 . 
     FIG. 4 is a side view of the spring steel cable retainer  20  or  22  of FIG.  3 . The cable retainer  20  is depicted with a forward edge  124  and a trailing edge  126 . When inserted into the housing, as shown in FIG. 3, forward edge  124  will slide into inbound insert aperture  24 . Referring again to FIG. 4, cable retainer  20  includes outward projecting tangs  52 A and  56 A and two of the inward projecting cable tangs  110   a  and  110   c  at staggered distances from forward edge  124 . Although aperture  108  is depicted, it is not functional in the present invention but is used to hold the blank during the manufacturing process when the spring steel blank (not shown in FIG. 4) is formed into the tubular spring steel  20  cable retainers  20  and  22 . 
     FIG. 5 is an end view of spring steel retainer  20  or  24  as viewed from forward edge  124  showing staggered cable tangs  110 A,  110 B and  110 C oriented toward forward edge  124 . Outward projecting tangs  52 A,  56 A are oriented toward the trailing edge (not shown in FIG.  5 ). The purpose of triangle-shaped gripper  122  is to secure the cable retainer during the manufacturing process and is not functional to the operation of the retainer in the present invention. During its manufacture, cable retainer  20  is formed from a flat blank and is therefore not continuous, as shown in FIG. 5, with a gap  118  existing between the two ends of the blank that has been formed into a circular shape. 
     Referring to FIGS. 4 and 5, the spring steel cable retainer  20  is adapted to receive a helically wound shielded cable (not shown in FIGS. 4 and 5) when inserted from trailing edge  126  toward forward edge  124 . The inwardly extending tangs  110   a ,  110   b ,  110   c  are staggered at distances from trailing edge  126  that permit them to find and seat in the existing grooves in the helically wound shielded cable. Once the cable is inserted fully in the cable retainer  20 , past all the inwardly extending tangs  110   a ,  110   b ,  110   c , the cable retainer  20  will resist removal of the cable by any rearward force applied to it. The cable retainer  20  is shown in FIGS. 4 and 5 prior to its insertion in the inbound insert aperture  24  of the present invention to aid in describing its function in the present invention. The reader should realize that the cable retainer  20  will function best to grip the cable when secured in the inbound insert aperture of the housing or insert described previously. When later secured in the inbound insert aperture, the gap  118  shown in FIG. 5 will be minimal and the outward expansion of the cable retainer  20  will be constrained by the cylindrical walls of the inbound insert aperture. 
     As shown in FIG. 5, the inwardly extending cable tangs  110   a ,  110   b ,  110   c  are oriented as shown, about 90° apart. The orientation of tangs  110   a ,  110   b , and  110   c  serve to receive and engage an armored cable inserted from the inbound end of the housing (not shown in FIG. 5) and guide the cable toward the cylindrical outbound end of the housing in a manner that separate cables are advanced to the outbound end without mutual interference. 
     Referring to FIG. 6, an end view of the inbound end  14  of the housing  12  of the preferred embodiment of FIG. 3, the spring steel cable retainers  20 ,  22  are shown locked into their respective inbound insert apertures  24 ,  26 . As shown in FIG. 6, tangs  110   a ,  110   b , and  110   c  are oriented to receive and engage an armored cable (not shown in FIG. 6) inserted from the inbound end  14  of the housing  12  and guide the cable toward the aperture  15  in the outbound end of the housing  12  in a manner that separate cables are advanced to the outbound end without mutual interference. The smooth interior surface  38  of the shoulder portions of the housing  12  also serve to guide the cables to the outbound end aperture  15 . The orientation of the inwardly extending tangs  110   a ,  110   b ,  110   c  of the cable retainers  20 ,  22  are critical as cable retainer  22  on the right side of FIG. 6 guides its cable upward in the housing  12  and toward the outbound end aperture  15  while cable retainer  24  on the left side of FIG. 6 guides its cable downward in the housing  12  and toward the outbound end aperture  15 . The net result is that separation is maintained between the cables allowing them to slip by one another and through the housing  12  to the outbound end aperture  15 . 
     As the invention has been described, it will be apparent to those skilled in the art that the same may be varied in many ways without departing from the spirit and scope of the invention. Any and all such modifications are intended to be included within the scope of the appended claims.