Abstract:
A battery connector ( 20 ) is provided that can be especially useful as a side-terminal adapter for use with a Kelvin connection. In one form, the connector comprises an insulator ( 70 ) sandwiched between an elongated first conductor ( 30 ) having a longitudinal axis and an elongated second conductor ( 50 ), wherein the first conductor and second conductor are slidably movable relative to each other. The first and second conductors respectively include first and second battery-terminal contact portions ( 38, 58 ) which are opposite each other and slidable relative to each other. A biasing member ( 48 ) biases the battery-terminal contact portions toward each other and a handle ( 90 ) is provided to exert a pressure against the bias to move the battery-terminal contact portions apart.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to electrical connectors. The invention has particular application to battery terminal clamps, especially to clamp adapters for side-terminal batteries. 
     Various types of connectors have been used for electrically connecting to battery terminals. However, traditional battery clamps are often difficult to position on side-terminal batteries. Because of this, various side-terminal adapters have been designed to connect to this type of terminal and allow easier use of traditional battery clamps. Likewise, specialized side-terminal clamps have also been designed specifically for dealing with side-terminal batteries. Examples of battery terminal connectors and side-terminal adapters are shown in U.S. Pat. Nos. 1,651,294; 2,267,826; 3,745,516; 4,377,317; 4,565,414; 5,662,504 and 5,862,515. 
     The prior art side-terminal adapters and battery clamps were often designed with two pivoting toothed jaws biased closed to grip a terminal therebetween. The teeth used in this design often provide minimal electrical contact with the side terminals and could easily inadvertently fall off. 
     Some side-terminal adapters provided a metal plate with a slotted opening between two relatively stationary toothed jaws. With this type of device, the side-terminal bolts are wedged in the opening between the jaws. However, this design tends to fail because the jaws can bend away from one another, especially when the device is attached and removed during repeated use. This bending can cause the quality of both the physical and electrical connections to deteriorate. Furthermore, any attempt to engage too large a terminal with the side-terminal adapter can permanently deform this type of device and render it useless. 
     Various types of circuitry and connectors have been used to make Kelvin connections that are often used for battery testing equipment. The minimal electrical contacts of prior battery clamps and side-terminal adapters become even more of a problem when a Kelvin connection is needed to test a battery. A Kelvin connection is a four point connection technique that allows current to be injected into a battery through a first pair of connectors attached to the battery terminals, while a second pair of connectors is attached to the battery terminals in order to measure the voltage across the terminals. Often modified alligator-type clamps, with the jaws electrically isolated from each other, are used to make the connections. In that case, each electrical contact is even more tenuous because only a single jaw provides each connection. Examples of such circuitry and connectors are shown in U.S. Pat. Nos. 2,267,826; 4,505,032; 5,234,359; 5,574,355; 5,592,093; 5,744,962; 5,753,920; 5,757,192; 5,831,435; 5,862,515; 5,886,530; and 5,901,002. 
     Furthermore, testing a battery using a Kelvin connection to the prior-art side-terminal adapters, instead of directly to the terminals themselves, is less accurate. An increase in measurement error occurs because the terminal adapters provide additional resistance in the current path, thereby affecting the measurement. 
     Thus, these prior electrical connectors often provide tenuous mechanical and electrical connections to the battery. Likewise, battery tests are prone to inaccuracy when standard side-terminal adapters are used to make Kelvin connections. 
     SUMMARY OF THE INVENTION 
     It is a general object of the invention to provide an improved electrical connector which avoids the disadvantages of prior connectors, while affording additional structural and operating advantages that allow it to be easily used with a side-terminal battery. 
     A feature of the invention is the provision of an electrical connector that can be easily used on a side-terminal battery. 
     A different feature of the invention is the provision of a side-terminal adapter having electrical contacts that are non-pivotally movable to contact a battery terminal. 
     Another feature of the invention is the provision of side-terminal adapter that can be more accurately used with testing equipment to make a Kelvin connection to a side-terminal battery. 
     The invention consists of certain novel features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present inventions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For the purpose of facilitating an understanding of the inventions, there is illustrated in the accompanying drawings preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated. 
     FIG. 1 is a perspective view of a battery connected to Kelvin connection, pivoting-jaw clamps via side-terminal adapters in accordance with the invention; 
     FIG. 2 is an enlarged, rear plan view of one of the side-terminal adapters of FIG. 1 in an open or mounting/demounting position; 
     FIG. 3 is the side-terminal adapter of FIG. 2 in its normal rest position; 
     FIG. 4 is the side-terminal adapter of FIG. 2 in a clamped position engaging a battery side-terminal; 
     FIG. 5 is a further enlarged, exploded perspective view of the side-terminal adapter of FIG. 3; and 
     FIG. 6 is a further enlarged perspective view of the side-terminal adapter of FIG.  3 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, there is illustrated a battery  12  having side mounted hex head terminals  14 . Two side-terminal adapters  20 , constructed in accordance with and embodying the features of the present invention, are respectively clamped to the terminals  14  to make Kelvin connection points at terminals  14 , as discussed below. A pair of pivoting jaw-type battery clamps  16  are respectively clamped to the side-terminal adapters  20  and are designed to continue the circuit that includes the Kelvin connection. Therefore, while one jaw of each clamp is connected to an associated cable  17  in standard fashion, the other jaw is connected to a separate wire  18  and the two jaws are electrically isolated from each other, all in a known manner. 
     Referring to FIGS. 2-6, side-terminal adapter  20  preferably comprises an elongated, substantially flat, plate-like member, such as a conductor  30  having a longitudinal axis. In a preferred form, conductor  30  includes fastener openings  32  sized to accept fasteners  31 . Grooves  34  are formed in one face of conductor  30  and deform it to form ribs (not shown) that extend out from the opposite face of conductor  30 . The grooves  34  and ribs are preferably provided adjacent the longitudinal edges of conductor  30  for additional structural strength, thereby allowing less material to be used. A cutout  36  is preferably provided at one end of conductor  30  and defines a terminal contact  38  contoured to engage terminal  14 . A flange, or lever  42 , preferably extends out from the opposite end of conductor  30  at approximately a right angle and is surrounded by an electrically insulating grip  44 . A seat  46  is preferably provided in the top face of grip  44  and is sized to accept compression spring  48 . 
     Another elongated, substantially flat, plate-like member, such as conductor  50 , is provided and also has a longitudinal axis. In a preferred form, conductor  50  is longer than conductor  30 . In a preferred form, conductor  50  preferably includes fastener openings  52  sized to accept fasteners  31 . Ribs  54  are preferably provided adjacent the longitudinal edge of conductor  50  for additional structural strength, thereby allowing less material to be used. In a preferred form, grooves (not shown) are formed on one face of conductor  50  and deform it to form ribs  54  on the opposite face. At one end of conductor  50 , an offset portion  55  is preferably provided. A cutout  56  spans the offset portion  55  and the adjacent end of the main portion of the conductor  50 . The cutout  56  defines a terminal contact  58  on the offset portion  55  contoured to engage terminal  14 . A flange, or lever  62 , preferably extends out from the opposite end of conductor  50  at approximately a right angle and is surrounded by electrically insulating grip  64 . A seat (not shown) is preferably provided in the bottom face of grip  64  and sized to accept the compression spring  48 . 
     An electrical insulator  70  is preferably provided and comprises an elongated, substantially flat, plate-like structure. Insulator  70  preferably includes fastener openings  72  sized to accept fastener  31 . A cutout  76  is provided at one end of insulator  70  and is preferably contoured to approximately align with at least a portion of cutout  36  (or  56 ). In a preferred form insulator  70  is slightly wider than conductors  30  and  50  and flanges  77  are provided along the longitudinal edges of insulator  70 . 
     In the preferred embodiment, conductors  30  and  50  are longitudinally slidably coupled together with insulator  70  sandwiched between them. A non-conductive fastener  31  can be used to fasten conductors  30  and  50  and insulator  70  together through fastener openings  32 ,  52  and  72 . At least one of fastener openings  32  and  52  are elongated to allow fastener  31  to slide within that elongated fastener opening, thereby allowing conductors  30  and  50  to slide relative to each other in a longitudinal direction (see FIGS.  2 - 4 ). Although openings  32  and  52  could both be elongated, it is preferred that only the openings  32  or the openings  52  be elongated in order to allow insulator  70  to remain fixed to one of conductors  30  and  50 . 
     In order to allow conductors  30  and  50  to make a Kelvin connection point at terminal  14 , insulator  70  electrically isolates conductors  30  and  50  from each other. Therefore, fastener openings  72  are preferably just large enough to accommodate fastener  31  in order to minimize the chances of arcing across insulator  70  through fastener openings  72 . A small fastener opening  72  also allows insulator  70  to be fixed to one of conductors  30  and  50  so that one conductor always remains completely covered while the conductors are sliding back and forth. 
     In a preferred form insulator  70  is slightly wider than conductors  30  and  50  and flanges  77  are provided along the longitudinal edges of insulator  70  to provide additional protection against arcing between the longitudinal edges of the conductors  30  and  50 . Flanges  77  also define a guide for the sliding movement of conductors  30  and  50 . It is also preferred that cutout  76  be contoured to and approximately align with one of cutouts  36  and  56  so that the insulator  70  does not interfere with making an electrical connection. 
     After conductors  30  and  50  are coupled together, terminal contacts  38  and  58  facing each other and cooperate to define the terminal connector  80  that clamps the battery terminal  14  therebetween. As conductors  30  and  50  slide back and forth, terminal contacts  38  and  58  move toward and away from each other. 
     When terminal contact  38  engages terminal  14 , one of the electrical connections necessary for the Kelvin connection is made. When terminal contacts  38  and  58  engage terminal  14 , two of the electrical connections necessary for the Kelvin connection are made. The second side-terminal adapter  20  makes the other two connections to the second terminal  14  of the battery for completing the Kelvin connection. 
     When conductors  30  and  50  are coupled together, levers  42  and  62  cooperate to define handle  90  at the end opposite terminal connector  80 . One end of compression spring  48  is inserted in seat  46  on the top face of grip  44  while the other end is inserted in the seat (not shown) in the bottom face of grip  64 . In the preferred form, spring  48  biases terminal connector  80  toward a closed rest position (shown in FIG. 3) or a clamped position (shown in FIGS.  1  and  4 ). When side-terminal adapter  20  is coupled to a terminal  14  of a side-terminal battery  12 , the portions of conductors  30  and  50  disposed above the top of battery  12  define two clamp-connecting portions  100  that are each engageable with a jaw of a jaw-type clamp (see FIG.  1 ). 
     The side-terminal adapter  20  is preferably operated by squeezing together levers  42  and  62  of handle  90  to overcome the biasing force of spring  48  and move terminal connector  80  to an open, or mounting/demounting position (shown in FIG.  2 ). When  9  handle  90  is released, terminal connector  80  closes. Handle  90  enables side-terminal adapter  20  to be easily coupled to a battery terminal  14  by squeezing and releasing handle  90  to open and close terminal connector  80 . 
     Preferably, the length and position of elongated openings  32  (or  52 ) is such that when terminal connector  80  is in its rest position of FIG. 3, it remains partially open, but with the remaining opening being smaller than terminal  14 . This allows a less obtrusive handle  90  to fit within a tight engine compartment because the handle need move only a small distance. It also reduces the compression of spring  48  required to apply terminal connector  80  to the battery terminal  14  in a clamped position and therefore reduces the spring force on the battery terminal, which could cause it to shear or deform. This is important because the terminal connector  80  can be clamped to a deformable substance, such as a lead battery terminal on a warm day. 
     When side-terminal adapter  20  is assembled, ribs  54  on conductors  30  and/or  50  preferably face the other conductor to define a reduced area of contact with insulator  70 . This reduced area of contact is a friction-reducing structure that reduces the amount of friction caused by moving conductors  30  and  50  relative to each other and allows a weaker spring  48  to overcome the smaller frictional force. 
     In the preferred form, conductor  50  includes offset portion  55  that approximately aligns terminal contact  58  with terminal contact  38  in one plane in the assembled condition of the adaptor  20 . By aligning terminal contacts  38  and  58  of the clamp, the compressive forces on the battery terminal  14  are also aligned. This alignment prevents two offset forces from shearing through terminal  14  or from causing side-terminal adapter  20  to tilt on terminal  14 . Offset portion  55  also acts as a stop that prevents terminal connector  80  from fully closing when it is in a rest position. 
     It will be appreciated that there are many variations and other uses for the side-terminal adapters  20 . For example, each conductor  30  and  50  could be attached directly to cable  17  or wire  18  or to different cables/wires that continue the circuit including the Kelvin connection, thereby eliminating the need for clamps  16 . Likewise, side-terminal adapter  20  could be used as the clamp on a pair of jumper cables or the like. Insulator  70  could be omitted and the side-terminal adapters  20  could then be used as side-terminal adapters for standard jumper cables. Additionally, side-terminal adapter  20  could be modified to include a terminal connector  80  on each end in order to connect multiple batteries together. Likewise, the side-terminal adapter  20  could be used without modification on batteries having top post terminals. 
     Although terminal connector  80  is shown with a smooth contour, a plurality of teeth or prongs can be used instead to engage with the battery terminal  14  and provide an electrical connection. Although terminal contacts  38  and  58  define an opening even when the terminal connector  80  is in its rest condition, the connector could be altered so terminal contacts slide past each other so no opening exists when the terminal clamping portion is in a closed or rest position. Although plate-like conductors  30 ,  50  are depicted, they can be curved, cylindrical, or other suitable shape. However, because of the compactness of many engine compartments, a relatively flat conductor is preferred. Also, non-conductive members may be substituted for conductors  30  and  50  and an electrically conductive path, such as a cable, could be coupled to conductive terminal connector  80 . Although it is preferable that conductors  30  and  50  slide longitudinally with respect to each other, they could be made to slide at an angle to the longitudinal direction. While the slidable connection shown involves a fastener that moves in an elongated opening, a different sliding connection could be substituted. Also, ribs  54  that decrease the force of friction could be provided on the faces of the insulator  70 . Likewise, raised dots or other shapes can be substituted for ribs  54  to further decrease the surface areas in contact and further reduce friction. It can also be advantageous to make the insulator of a low-friction material, such as PTFE of the type sold under the trademark Teflon. 
     While particular embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.