Abstract:
A trailer hitch ground connector apparatus includes a first positive clamping and electrically conductive instrument that has at least one penetrating clamp surface; and a cable operatively electrically connected with the first instrument at a first end of said cable.

Description:
CROSS-REFERENCE RELATED APPLICATIONS 
       [0001]    This is a non-provisional and claims the priority under 35 USC §119(e) of U.S. Patent Application Ser. No. 62/155,705 filed Apr. 30, 2015, hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The invention relates to towed vehicles and, more particularly, to the electrical connections made at trailer hitches. 
         [0004]    2. Discussion of Art 
         [0005]    Towed trailers are useful in transporting household goods, auxiliary vehicles, and recreational equipment. Towed trailers may be used at any hours of the day or night. For example, when departing for a fishing trip, it is desirable to be in the boat on the water just around dawn when the fish are biting. This requires driving the boat to the water pre-dawn. 
         [0006]    When towing a trailer in darkness, it is desirable both for the tow driver and for following vehicles that the trailer should be lit. Otherwise the bulk of the unlit trailer can obscure the lights of the towing vehicle, causing calamity. For this reason, at the time when a trailer hitch is installed, an electrical harness typically also is installed for providing power from the towing vehicle for lighting the trailer. 
         [0007]    However, conventional trailer electrical harnesses present a problem with corrosion of the ground connection. Power and signal connections are made within a watertight gang plug, but also require a good ground to work properly, or at all in some cases. The ground connection typically is made from chassis to chassis, e.g., via the trailer hitch ball or via a grounding wire that is run through the vehicle and trailer wiring harnesses and attached to the trailer via a bolt or screw. Over time, the trailer hitch ball will rust, which will degrade the quality of the ground connection. Or the original ground wire, if the trailer is equipped with one, can chafe, corrode, or break, creating a faulty ground. A poor ground connection will cause power and lights to flicker or to not work at all as the hitch moves on the ball during vehicle travel. 
         [0008]    Occasionally, an inexperienced operator will attempt to remedy the corrosion problem by painting the hitch ball. This has the result of completely interrupting the ground connection, rendering the lights inoperable on any trailer mounted to the hitch. 
         [0009]    Another conventional approach to trailer hitch ground connectors, is to provide a bolted electrical connection to the vehicle chassis with a wire leading either to a ground prong of a (non-standard) trailer electrical harness, or to a ring terminal that must then be bolted to the trailer chassis. These types of bolt-and-wired ground connections typically rust out at the vehicle end, with the result that vehicle motion causes the bolt to unexpectedly drop out of the rusted hole as the vehicle and trailer proceed down the highway. Understandably, following drivers will be disconcerted by a trailer that “disappears” into the night as its lights go out. 
         [0010]    Thus, it would be advantageous to have an apparatus that provides a reliable and durable ground connection at a trailer hitch. 
       BRIEF DESCRIPTION 
       [0011]    Embodiments of the invention feature a trailer hitch ground connection that is formed by a positive clamp that has at least one penetrating jaw. By “positive” is meant capable of being locked into a clamped position, preferably any arbitrary position within a range of positions. By “penetrating” is meant sufficiently sharp so as to pierce through paint or rust to make clean metal-to-metal contact for a solid ground connection. 
         [0012]    Certain exemplary embodiments, as briefly described above, are illustrated by the following figures. 
     
    
     
       DRAWINGS 
         [0013]      FIG. 1  shows a first embodiment of the invention, in which a spring-clamp pliers is used as a positive penetrating clamp for a ground connection at an end of a ground connector cable. 
           [0014]      FIG. 2  shows a second embodiment of the invention, in which spring clamp pliers are provided as positive penetrating clamps at both ends of a ground connector cable. 
           [0015]      FIG. 3  shows detail of a spring clamp pliers as shown in  FIG. 2 . 
           [0016]      FIG. 4  shows a third embodiment of the invention, in which screw clamps are provided as positive penetrating clamps at both ends of a ground connector cable. 
           [0017]      FIG. 5  shows detail of a screw clamp as shown in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring to  FIG. 1 , a trailer hitch  10  can be pivotally attached to a vehicle  12  by way of a ball  14  and a chain  16 . A cable  18  provides positive electrical connection from the vehicle  12  to the trailer hitch. The hitch  10  and the ball  14  can provide a conventional grounded electrical connection from the trailer back to the vehicle  12 . However, according to a first embodiment of the invention, the conventional ground connection can be supplemented by a ground connector cable  20 . The ground connector cable  20  is attached to a tongue  22  of the trailer hitch by a bolt  24  (or similar conductive fastener), and is attached to the vehicle  12  by a positive clamping instrument  26 , e.g., a spring clamp pliers. 
         [0019]      FIG. 2  shows a second embodiment of the invention, in which a positive clamping instrument  26  is operatively electrically connected at each of the ends of the ground connector cable  20 . In this view, each positive clamping instrument is a spring clamp pliers. Each spring clamp pliers  26  has jaws  30  that are operable in an adjustable locking manner by conventional handles  31 . Each of the jaws  30  has a gripping surface or anvil  32 . Referring to  FIG. 3 , which shows in detail the jaws  30  and anvils  32  of a single spring clamp pliers  26 , it can be seen that each anvil  32  is shaped to provide a penetrating edge  34 . In use, the spring clamp pliers  26  are locked onto the vehicle  12  or the trailer hitch  10  to provide a solid ground connection via the penetrating edges, despite surface corrosion. 
         [0020]      FIG. 4  shows a third embodiment of the invention, by which screw clamps  40  are provided as positive clamping ground connectors. The screw clamps  40  are operatively electrically connected with each other via the grounding connector cable  20 . Each of the screw clamps  40  has a body  42 , which includes an anvil  43 . Each of the screw clamps  40  also includes a screw  44  which is positively adjustable toward the anvil  43 . Each screw  44  is sharpened to a penetrating point  46 , better shown in  FIG. 5 . Thus, when in use each clamp  40  is screwed onto a metal structure such as a vehicle bumper or a trailer chassis, the penetrating points  46  pierce through any surface corrosion to obtain a clean metal-to-metal electrical contact at each end of the grounding cable  20 . 
         [0021]    Although exemplary embodiments of the invention have been described with reference to attached drawings, those skilled in the art nevertheless will apprehend variations in form or detail that are consistent with the scope of the invention as defined by the appended claims.