Abstract:
A set screw electrical connector assembly includes an electrical connector and a set screw drive plug. The connector includes at least one set screw portal sized to accommodate a set screw therein. The set screw drive plug is formed of electrically insulative material and is configured to engage and drive the set screw into the connector. The connector assembly may include an insulative housing formed about the connector for providing a water tight seal with a cable terminated to the connector.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to U.S. Provisional Application No. 60/642,399, filed Jan. 7, 2005. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention is directed to a submersible set screw electrical connector. More particularly, the present invention relates to a connector employing an insulated and water-tight set-screw driver.  
       BACKGROUND OF THE INVENTION  
       [0003]     Set screw electrical connectors are commonly used to connect or splice distribution cabling to a bus bar. Such connectors generally include a rectangular aluminum or conductive alloy body having a series of openings therein sized to accommodate a transformer stud, prepared cabling and the associated set screws securing the stripped conductors or the cables to the connector. These connectors are often found in locations that are exposed to moisture or are underground. Thus, the connector should provide for water tight connection.  
         [0004]     U.S. Pat. No. 5,533,912 discloses a typical design for a set screw electrical connector that prevents water from entering therein. This design encapsulates the connector body with somewhat flexible water-impervious material. The encapsulation includes a series of hollow sleeves which project from the connector body. Certain of the sleeves are designed to accept the cabling therein while others are sized to accommodate the metal set screw. Once the set screw is tightened against the stripped wire conductor, a removable plug or cap is then inserted into this sleeve to seal the opening. A drawback of this typical design is the likelihood that one or more plugs will be lost or not inserted and thus the entire connector will be compromised. Another drawback is that when the user tightens the set screw, there is the risk of electrical shock hazard because the tool employed by the user is usually metal and such a tool will readily conduct electricity directly to the user or to any object coming into contact with the tool during installation if the cable is energized.  
         [0005]     U.S. Pat. No. 6,764,354 discloses a variation of the above in that it incorporates a wholly plastic set screw having a threaded lower body portion, a round intermediate body portion and a hex head. The lower body portion is threaded into the connector to secure the cabling in place while the round intermediate body portion forms a seal with the encapsulating material. Obviously, one drawback to this design is the great difference in strength between the metal threads of the connector and the plastic threads of the set screw. Stripping of the plastic threads is likely and thus inadequate compression of the bare conductor will result. This can cause arcing within the connector that will lead to failure. Also, by eliminating the metal set screw, there is less electrical contact between the bare conductor and the electrical connector.  
       SUMMARY OF THE INVENTION  
       [0006]     It is therefore an object of the present invention to provide a set screw electrical connector which incorporates a metal set screw while simultaneously electrically insulating the user (and anything else in contact with the user&#39;s tool) from this set screw during insertion and rotation.  
         [0007]     Another object of the present invention is to provide an electrical connector with a metal set screw so that greater electrical contact between the connector and the bare conductor is possible.  
         [0008]     A further object of the present invention is to eliminate the need for separate plugs or caps to seal the set screw openings thereby eliminating the chance that they will be lost or damaged which would render the connector unsuitable for wet locations.  
         [0009]     A further object of the present invention is to provide an electrical connector wherein once the set screw is properly tensioned, no further operation is needed to also make the connector watertight.  
         [0010]     The present invention provides a set screw electrical connector assembly including an electrical connector housing having at least one set screw portal which is sized to accept the set screw therein. A set screw drive plug is formed of electrically insulated material and is configured to engage and drive the set screw into the connector.  
         [0011]     In a preferred embodiment of the present invention, the set screw is formed of metal and the electrical connector includes a waterproof sleeve which encircles the set screw portal and extends outwardly away from the connector. The set screw drive plug forms a seal with the waterproof sleeve.  
         [0012]     In a method aspect of the present invention, a method of sealing a set screw within a set screw connector is provided. The method includes partially threading a set screw within a set screw portal of the set screw connector and thereafter fully driving the set screw into the set screw connector via a set screw drive plug which is electrically insulated. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is an exploded plan view, partially in section, of the connector assembly of the present invention in its unassembled state.  
         [0014]      FIG. 2  is a plan view, partially in section, of the connector assembly of  FIG. 1 .  
         [0015]      FIGS. 3-5 , are respectively, top, side, and bottom views of the set screw driver used in the connector assembly of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]     An electrical connector assembly  1  of the present invention is shown. Referring to  FIGS. 1 and 2 , electrical connector  10  is shown encased within waterproof housing  12 . Both connector  10  and housing  12  are of typical material and construction. Connector  10  may be an electrically conductive single bar or may be formed of multiple parallel (and electrically inter-connected) conductive bars for even more connection options. Housing  12  is an electrically insulative plastic member which may be applied about connector  10  is via molding. However, other methods of application are also suitable. As shown in  FIGS. 1 and 2 , the housing  12  covers the connector  10  and additionally forms extending sleeves  18  and  40  which will be described in further detail hereinbelow.  
         [0017]     During assembly of connector  10 , a cable  14  is prepared by stripping or baring an end portion of the insulation  15  to expose conductor  16 . This prepared cable  14  is then inserted into a cable sleeve  18  formed by housing  12  and through cable aperture  19  until bare conductor  16  is fully within connector area  20 . In this embodiment, to prevent water from likewise entering, sleeve  18  is shown as being configured with one or more internal ribs  22  that engage and seal around the outside of cable insulation  15 . Such ribs  22  are optional as other means of preventing water entry are also feasible. Depending upon the degree to which these ribs  22  extend inwardly within sleeve  18 , different sizes of cable  14  can be accommodated within a single connector  10 .  
         [0018]     Set screw portal  24  of connector  10  also opens into connector area  20  with this portal  24  being threaded so as to accommodate like-threaded set screw  26 . Set screw  26  is preferably metal so that it can establish electrical contact with bare conductor  16 . Set screw  26  also presses bare conductor  16  against opposite wall  28  of connector  10  for enhanced electrical connection.  
         [0019]     Set screw  26  is of typical construction having a female hex drive slot  30  so that a typical hex tool can be used to tighten set screw  26  against bare conductor  16  within connector  10 . Of course, other configurations of set screw  26 /drive slot  30  may also be employed. The hex configuration is shown herein as currently the industry typically employs hex drive slots.  
         [0020]     While the drawings only show one cable aperture  19  and one set screw portal  24  in connector  10 , in practice there would be multiple such openings spaced along all or a portion of the length of connector  10 . Similarly, insulative housing  12  may be formed to provide extending sleeves for each connector aperture and portal so that a multitude of cable connections can be made using a single connector assembly  1 .  
         [0021]     The present invention employs an insulated drive plug  32  to drive set screw  26 . Drive plug  32  is typically made of plastic material, but any other electrically insulating material such as rubber, for example, so long as it is stiff or hard enough to rotate set screw  26  under pressure without significant deformation. Plug  32  may also be made of multiple materials if so desired with one material being used for hex drive  34  while another, for example, is employed in head region  36 . The use of an insulative plug  32  is advantageous in that there is no electrically conductive path between bare conductor  16  and the tool employed by the user. Thus, even in the situation where a metal set screw  26  is employed within connector  10 , electrical isolation to the user is provided.  
         [0022]     Drive plug  32  can be a separate component from set screw  26  or the two may be permanently attached or secured together such as by an adhesive. Alternatively, it is also possible to form or mold drive plug  32  to or with set screw  26 .  
         [0023]     Drive plug  32  would also typically incorporate female hex opening  38  therein but other configurations are also likely. For example, drive plug  32  and more particularly head region  36  could be configured with a male driver such as a hex nut. The user would simply use a tool to engage drive plug  32  so as to rotate it and thus push or bias set screw  26  against bare conductor  16  within connector  10 .  
         [0024]     To make connector  10  watertight, housing  12  would further be configured with set screw sleeve  40 . This set screw sleeve  40  would typically extend from connector  10  and surround set screw portal  24 . As with cable sleeve  18 , the interior of set screw sleeve  40  could also be configured with one or more optional ribs  42  that project slightly inwardly. Optional ribs  42  would be located so as to engage head region  36  of drive plug  32 . In this fashion, by threading drive plug  32  into connector  10 , associated head region  36  would engage ribs  42  to thereby form a seal and prevent any moisture from also entering area  20  via this route. It should further be noted that a seal could also be formed directly between the smooth side walls of both head region  36  and the interior of set screw sleeve  40 .  
         [0025]     In operation, a user would insert cable  14  into opening  19  of connector  10  through sleeve  18  in the normal fashion. The bare conductor  16  would thereby reside in connector area  20 . Drive plug  32 , which in most cases would already be partially inserted within set screw sleeve  40  (i.e. coming from the manufacturer that way), would then be rotated by the user who would most likely employ a standard hex wrench. Under this arrangement, hex drive  34  of drive plug  32  would already be in full or partial engagement with hex drive slot  30  of set screw  26 . Continued rotation by the user of the tool will further cause drive plug  32  to engage bare bare conductor  16  and compress it against opposite wall  28  inside connector area  20  of connector  10 . This places the conductor  16  in secure mechanical and electrical engagement with connector  10 . Due to the construction of drive plug  32 , there is no electrically conductive path between the user and bare conductor  16  even if using a metal set screw  26  and a metal tool. Furthermore, upon rotating drive plug  32  within set screw sleeve  40 , head region  36  would engage ribs  42  so as to immediately form a seal between the two thereby preventing moisture from entering connector  10 . Also, there is no need to remove drive plug  32  from connector  10  to further tighten or remove set screw  26  as would be the case if connector  10  were sealed by removable caps or plugs or the like.  
         [0026]     While select preferred embodiments of this invention have been illustrated, many modifications may occur to those skilled in the art and therefore it is to be understood that these modifications are incorporated within these embodiments as fully as if they were fully illustrated and described herein.