Abstract:
An apparatus is provided for simultaneously coupling a towing vehicle energizing circuit to a tow-dolly lighting circuit and a towed-vehicle lighting circuit. The apparatus includes a unitary connector body having a first portion for mating with an output plug of the towing vehicle energizing circuit, a second portion for mating with an input plug of the tow-dolly lighting circuit, and a third portion for mating with an input plug of the towed-vehicle lighting circuit. The connector body includes a plurality of conductors, each of which connects a terminal in the connector body first portion to corresponding terminals in each of the connector body second portion and third portion. The apparatus of the invention can be used to simultaneously connect the towing vehicle energizing circuit to two trailer end 4-flat plugs, one to power-tow-dolly lights and a second to power vehicle-in-tow lights.

Description:
BACKGROUND 
       [0001]    This invention relates generally to vehicle electrical systems for trailer or tow-dolly towing connection. More particularly, it relates to an electrical connector that simultaneously connects a towing vehicle lighting circuit to both tow dolly lights and vehicle-in-tow lights. 
         [0002]    Connectors for connecting a towing vehicle to trailer lights or tow-dolly lights are well known. The 4-flat plug is a common towing light connector plug configuration, and is widely used on trailers and tow-dollies. A conventional 4-flat plug has a “towing vehicle end,” which is attached to the lighting circuits of a towing vehicle, and a “trailer end,” which is part of a trailer or tow-dolly wire harness and mates to the towing-vehicle plug thereby establishing electrical connection necessary for proper operation of trailer or tow-dolly lights.  FIG. 1  shows a conventional 4-flat plug configuration. 
         [0003]    When a tow-dolly (rather than a trailer) is attached to a towing vehicle, there is a need not only for operational lights on the tow-dolly itself, but also for operational lights at the rear of the vehicle-in-tow. To provide such vehicle-in-tow lighting, it has been common to attach temporary lights to the rear of the vehicle. For example, such lights can be magnetically mounted to the vehicle trunk surface or attached to plastic flaps that hang from the vehicle trunk and are held in place by the trunk lid. These tow-lights often utilize the same 4-flat plug confirmation that is common to trailers and tow-dollies. 
         [0004]    Because the tow-dolly 4-flat plug and the vehicle-in-tow temporary lights both must connect to the towing vehicle 4-flat plug a towing vehicle driver will sometimes elect to energize either the tow-dolly lights or the vehicle-in-tow lights, but not both. In other cases, if the driver has necessary tools and knowledge, he or she may leave the tow-dolly lights plugged in, and make splice connections to energize the vehicle-in-tow lights. 
         [0005]    There is currently a need, therefore, for an improved apparatus that can simultaneously connect a towing vehicle lighting circuit to both tow-dolly lights and to vehicle-in-tow lights. It is an object of the present invention to provide such an apparatus. 
         [0006]    Additional objects and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims. 
       SUMMARY OF THE INVENTION 
       [0007]    To achieve the foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described in this document, there is provided an apparatus for simultaneously coupling a towing vehicle energizing circuit to a tow-dolly lighting circuit and a towed-vehicle lighting circuit. The apparatus includes a unitary connector body having a first portion for mating with an output plug of the towing vehicle energizing circuit, a second portion for mating with an input plug of the tow-dolly lighting circuit, and a third portion for mating with an input plug of the towed-vehicle lighting circuit. The connector body includes a plurality of conductors, each of which connects a terminal in the connector body first portion to corresponding terminals in each of the connector body second portion and third portion. 
         [0008]    In one embodiment, the connector body comprises a molded plastic body. The connector body first portion is configured to mate with an input plug that is a 4-pin flat connector. The connector body second portion is configured to mate with an input plug of the tow-dolly lighting circuit that is a 4-pin flat plug. The connector body third portion is configured to mate with an input plug of the vehicle-in-tow lighting circuit that is a 4-pin flat plug. In this embodiment, the apparatus of the invention can be used to simultaneously connect the towing vehicle energizing circuit to one 4-flat plug to power-tow-dolly lights and a second 4-flat plug to power vehicle-in-tow lights. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate the presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred methods and embodiments given below, serve to explain the principles of the invention. 
           [0010]      FIG. 1  shows a typical connector assembly known in the prior art for coupling a towing vehicle electrical harness to a trailer or tow-dolly electrical harness. 
           [0011]      FIG. 2  depicts a connector assembly according to one embodiment of the present invention, showing a plug adaptor for simultaneously coupling a 4-pin flat towing vehicle harness plug to a 4-pin flat tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug, wherein the adaptor has a unitary plug body. 
           [0012]      FIG. 3  depicts a connector assembly according to a second embodiment of the present invention wherein the adaptor includes three plug bodies connected by wiring harnesses. 
           [0013]      FIG. 4  depicts a connector assembly according to another embodiment of the present invention, showing a plug adaptor for simultaneously coupling a 5-pin flat towing vehicle harness plug to a 4-pin flat tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug. 
           [0014]      FIG. 5  depicts a connector assembly according to another embodiment of the present invention, showing a plug adaptor for simultaneously coupling a 6-pin round towing vehicle harness plug to a 4-pin flat tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug. 
           [0015]      FIG. 6  depicts a connector assembly according to another embodiment of the present invention, showing a plug adaptor for simultaneously coupling a 7-pin round towing vehicle harness plug to a 4-pin flat tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Reference will now be made in more detail to presently preferred embodiments of the invention, as illustrated in the accompanying drawings. While the invention is described more fully with reference to these examples and drawings, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrative examples shown and described. Rather, the description which follows is to be understood as a broad, teaching disclosure directed to persons of ordinary skill in the appropriate arts, and not as limiting upon the invention. 
         [0017]    Referring now specifically to the drawings,  FIG. 1  shows a typical configuration of a towing electrical connector assembly  10  for connecting the electrical systems of a towing vehicle and a tow-dolly or trailer. The connector assembly  10  includes a towing vehicle plug  12  attached to a towing vehicle electrical harness  14  and a mating trailer plug  16  attached to a trailer electrical harness  18 . The towing vehicle plug  12  includes three lighting circuit pin receptacles  21   a ,  21   b ,  21   c  and a ground pin  23  and is configured to mate with a standard 4-pin flat trailer harness plug connected to a trailer electrical harness. Each of the lighting circuit pin receptacles  21   a - c  is connected to a corresponding energizing circuit wire  25   a - c  of the towing vehicle electrical harness  14 . The ground pin  23  is connected to a ground wire  27  in the towing vehicle electrical harness  14 . Each of the energizing circuit wires  25   a - c  is connected to a light energizing circuit of the towing vehicle (not shown) for energizing one of the tail lamp, right turn lamp and left turn lamp of the trailer. The ground wire  27  is grounded to the towing vehicle frame. The trailer harness plug  16  includes three lighting circuit pins  20   a ,  20   b ,  20   c  and a ground pin receptacle  22  and is configured to mate with a standard 4-pin flat towing vehicle plug connected to a towing vehicle harness. Each of the lighting circuit pins  20   a - c  is connected to a corresponding lighting circuit wire  24   a - c  of a trailer electrical harness  18 . The ground pin receptacle  22  is connected to a ground wire  26  in the trailer electrical harness  18 . Each of the lighting circuit wires  24   a - c  is connected to a lighting circuit of the trailer (not shown) for one of the tail lamp, right turn lamp and left turn lamp. The ground wire  26  is grounded to the trailer frame. 
         [0018]      FIG. 2  shows an exemplary embodiment of a connector assembly  11  for mating a 4-pin flat towing vehicle harness plug  12  with a 4-pin flat a tow-dolly harness plug  16   a  and a 4-pin flat vehicle-in-tow harness plug  16   b . The connector assembly  11  includes a plug adaptor  30  that has a female end  31  and male end  32 . The male end  32  is configured to mate with the 4-pin flat towing vehicle harness plug  12 . Adapter pins  34   a ,  34   b  and  34   c  and a ground receptacle  35  are disposed in the adapter male end  32  and are configured to mate with the three lighting circuit pin receptacles  21   a ,  21   b ,  21   c  and the ground pin  23  of the towing vehicle plug  12 . The female end  31  of the adaptor  30  has a first portion  33  configured to mate with the tow-dolly harness plug  16   a . Each of the pins  34   a ,  34   b  and  34   c  is connected to a corresponding conductor  36   a - c . Conductor  36   a  is in turn connected to a pair of the pin receptacles  37   a / 38   a  disposed in the adapter female end first portion  33 . Similarly, conductor  36   b  is connected to a pair of the pin receptacles  37   b / 38   b  and conductor  36   c  is connected to a pair of the pin receptacles  37   c / 38   c . The ground pin receptacle  35  is connected to a ground lead  36 , which in turn is connected to a ground pin  39  disposed in the adapter female end first portion  33 . 
         [0019]    Still referring to  FIG. 2 , the female end  31  of the adaptor  30  also has a second portion  41  configured to mate with the vehicle-in-tow harness plug  16   b . Each of the pins  34   a ,  34   b  and  34   c  also is connected to one of the corresponding pin receptacles  38   a ,  38   b ,  38   c  disposed in the adapter female end second portion  41 . The ground lead  36  also is connected to a ground pin  40  disposed in the adapter female end second portion  41 . 
         [0020]    In the configuration of  FIG. 2 , it can be seen that the adaptor  30  can be used to connect the 4-pin flat towing vehicle harness plug  12  with both the 4-pin flat a tow-dolly harness plug  16   a  and the 4-pin flat vehicle-in-tow harness plug  16   b  at the same time. 
         [0021]      FIG. 3  shows a second exemplary embodiment of an adapter according to the present invention for connecting a 4-pin flat towing vehicle harness plug with a 4-pin flat a tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug. The adapter  30  has a first plug  50  configured for mating with the output plug  12  of the towing vehicle energizing circuit, a second plug  60   a  for mating with the tow-dolly harness plug  16   a  and a third plug for mating with the vehicle-in-tow harness plug  16   b . The first plug  50  has a male end  52  configured to mate with the 4-pin flat towing vehicle harness plug  12 . Adapter pins  34   a ,  34   b  and  34   c  and a ground pin receptacle  35  are disposed in the adapter male end  52 , as previously described. Each of the pins  34   a ,  34   b  and  34   c  is connected to a pair of harness wires that exit the plug  50 , as described below. The second plug  60   a  has a female end  62   a  configured for mating with the input plug of the tow-dolly lighting circuit  16   a . Disposed in the second plug female end  62   a  are pin receptacles  37   a ,  37   b ,  37   c  and ground pin  39 . The third plug  60   b  has a female end  62   b  configured for mating with the input plug of the towed-vehicle lighting circuit  16   b . Disposed in the third plug female end  62   b  are pin receptacles  38   a ,  38   b ,  38   c  and ground pin  40 . 
         [0022]    Still referring to  FIG. 3 , each of the pins  34   a ,  34   b ,  34   c  and ground pin receptacle  35  is connected to the corresponding pin receptacles  37   a ,  37   b ,  37   c  and ground pin  39  of the second plug  60   a  by corresponding conductors  53   a - d  of a connecting harness  54 . Similarly, each of the pins  34   a ,  34   b ,  34   c  and ground pin receptacle  35  is connected to the corresponding pin receptacles  38   a ,  38   b ,  38   c  and ground pin  40  of the third plug  60   b  by corresponding conductors  55   a - d  of a connecting harness  56 . 
         [0023]    In the configuration shown in  FIG. 3 , the adaptor  30  can be used to connect the 4-pin flat towing vehicle harness plug  12  with both the 4-pin flat a tow-dolly harness plug  16   a  and the 4-pin flat vehicle-in-tow harness plug  16   b  at the same time. 
         [0024]    Other embodiments of connector assemblies according to the present invention can be provided for simultaneously connecting other common towing vehicle plug configurations, such as 5, 6, or 7-wire plug configurations, to a tow-dolly harness plug and a vehicle-in-tow harness plug. For example,  FIG. 4  shows a connector assembly according to the present invention for connecting a 5-pin flat towing vehicle harness plug with a 4-pin flat tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug.  FIG. 5  shows an exemplary connector assembly for connecting a 6-pin round towing vehicle harness plug to a 4-pin flat tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug.  FIG. 6  shows another exemplary adapter for connecting a 7-pin round towing vehicle harness plug to a 4-pin flat tow-dolly harness plug and a 4-pin flat vehicle-in-tow harness plug. In the embodiments shown in  FIGS. 4-6 , it is only necessary to provide conductors  36  and  36   a - c  to connect to the pins of the tow-dolly and vehicle-in-tow harness plugs for the ground, left turn, right turn and tail light circuits. 
         [0025]    From the foregoing, it can be seen that the apparatus of the present invention possesses numerous advantages. Among these, the apparatus can be used to simultaneously send towing vehicle electrical signals, such as braking and turning lights initiated from the towing vehicle, to both the tow-dolly lights and the vehicle-in-tow lights. 
         [0026]    Upon reading this disclosure, those skilled in the art will appreciate that various changes and modifications may be made to the preferred embodiments of the invention and that such changes and modifications may be made without departing from the spirit of the invention. For example, although the connector may be designed for the most common trailer plug configuration, the 4-flat plug, any other common configuration, such as the 5, 6 or 7-wire configurations, also can be used. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.