Patent Publication Number: US-6902444-B1

Title: Battery terminal connection assembly

Description:
FIELD OF THE INVENTION 
   The invention relates to the field of electrical connections, and, more particularly, to connections between battery terminals ans cables. 
   BACKGROUND OF THE INVENTION 
   Powerful batteries are necessary for many devices utilized today. For instance, material handling equipment, lift trucks and other similar vehicles require batteries for use. Such equipment typically experiences rough treatment and must have durable electrical connections. 
   In the past, two methods have been used to provide such connection between the power source and the equipment. The first method required that the end of a cable be stripped of its protective insulation and welded directly to the battery terminal. Such a connection provided extremely durable electrical connection. However, the welding resulted in a near-permanent connection. Such a connection was a hindrance after the battery&#39;s power was depleted. Typically, disconnection could only be performed by additional welding. Because welding flames are not permitted in many warehouse or other industrial settings, removal had to be performed offsite which is timely and costly. In addition, such welding often ruined the battery for future use, i.e., recharging and reuse. 
   The second method utilized a terminal connector which provided acceptable connection to the battery terminal. The terminal connector was connected to the cable through a friction fit. However, because the terminal connector was a “soft” metal which experienced “cold flow,” the connection between the terminal connector and the cable frequently became loose. Cold flow occurs when pressure is applied to a material and it flows away from the pressure. For instance, a threaded cavity in a lead material will experience cold flow when a screw is threaded into the cavity and stress is applied, i.e., the lead threads will move with respect to the cavity and loosen the connection between the screw and the lead material. Loosened connections result in electrical loss, potentially dangerous heat, and increased potential for corrosion. Therefore, this method of battery connection has required frequent tightening between the terminal connector and the cable. However, in practice such maintenance is not routinely performed and the battery connection suffers the above-noted problems. 
   Therefore, there is a need in the prior art for a method of connecting a battery to a cable which provides for durable electrical connection and removability. 
   A battery terminal connection assembly which addresses the problems of known devices would be an important advance in the art. 
   OBJECTS OF THE INVENTION 
   It is an object of the invention to provide a battery terminal connection assembly which overcomes the problems in the prior art. 
   Another object of the invention is to provide a battery terminal connection assembly which avoids cold flow by utilizing a cold-flow resistant sleeve to provide connection between the terminal and cable. 
   Another object of the invention is to provide a removable battery terminal connection assembly which provides a connection which is not affected by cold flow. 
   Another object of the invention is to provide a battery terminal and cable connection arrangement which provides for durable electrical connection. 
   Another object of the invention is to provide a battery terminal and cable connection arrangement which allows for quick and easy connection and disconnection. 
   Another object of the invention is to provide a battery terminal connection assembly which provides for connection and disconnection between a cable and battery terminals of various sizes. 
   Yet another object of the invention is to provide a battery terminal connection assembly which utilizes enduring friction contact between a cable fitting and a terminal connector to ensure electrical contact between a cable and a battery. 
   Still another object of the invention is to provide an efficient and economical way provide durable electrical connection between a battery terminal and a cable. 
   How these and other objects are accomplished will become apparent from the following descriptions and drawings herein. 
   SUMMARY OF THE INVENTION 
   This invention is a battery terminal connection assembly for connecting a battery terminal to a cable. The invention represents a significant advance over the state of the art by providing novel elements to provide improved and longer connection between terminals and cables. 
   The battery terminal connection assembly comprises a conductive cable fitting having a first and second end, a conductive terminal connector having an arm adapted to engage the terminal and including a hole, a cold-flow-resistant sleeve defining a bore for receiving the second end of the cable fitting positioned in the hole and bonded to the connector, and a tensioning member adapted to connect to the second end to urge the cable fitting into contact with the bore. The arm preferably forms an opening which is adapted to receive the terminal. The bore preferably defines a bore axis along which the tensioning member is adapted to urge the cable fitting. When assembled, the assembly allows the tensioning member to ensure electrical contact between the cable and the terminal. 
   The second end of the cable fitting preferably includes a cavity to receive the tensioning member. In certain preferred embodiments, the cavity is threaded and the tensioning member is a threaded bolt such that the bolt and cable fitting can be screwed together to urge the fitting into the bore along the bore axis. In such embodiments the cable fitting preferably includes an external portion adapted to be gripped when the bolt and cable fitting are screwed together. For instance, the external portion may be raised such that it can be engaged by a wrench. The tensioning member preferably includes a head and a lock washer which is adapted to abut the head and the connector when the bolt and cable fitting are screwed together. In certain embodiments, a washer is positioned between the lock washer and the connector. 
   The first end of the cable fitting preferably includes a recess adapted to receive the cable. The recess is preferably dimensioned to snugly receive the cable. The connection between the cable fitting and cable may be further strengthened by welding, soldering or other through other means. 
   The sleeve preferably extends from a proximal end to a distal end with at least one of the ends being non-circular such that rotation of the sleeve relative to the connector is prevented. For instance, the outer shape of the sleeve and the inner shape of the hole in the connector can be square-like, thus preventing rotation of the sleeve relative to the connector. As is understood, a sleeve and hole having any non-circular shape would prevent such rotation. 
   In certain embodiments, the cable fitting has a conical portion terminating at the second end and the bore has a conical portion terminating at the proximal end such that the cable fitting mates with the bore. In such embodiments, the conical portion of the cable fitting can be considered a shoulder which is urged into contact with the bore by the tensioning member. In other embodiments, a shoulder with a surface substantially perpendicular to the bore axis is urged into contact with the bore by the tensioning member. 
   The invention is also a battery terminal and cable connection arrangement which comprises a battery having a terminal; a conductive terminal connector having a hole and an arm adapted to engage the terminal; a cold-flow-resistant sleeve positioned in the hole, bonded to the connector, and defining a bore extending from a proximal end to a distal end; a conductive cable fitting having first and second ends and entering the proximal end such that the second end is received within the bore; a tensioning member entering the distal end of the bore, fixed to the second end of the fitting, and urging the cable fitting into contact with the bore; and a conductive cable fixed to the first end of the cable fitting. The terminal is preferably a terminal post which is received in and secured to an opening formed by the arm. 
   The invention can also be described as a battery terminal and cable connection arrangement comprising a battery having a terminal; a conductive terminal connector having a hole and a first connecting means for connecting to the terminal; a cold-flow-resistant sleeve positioned in the hole and bonded to the connector, the sleeve defining a bore extending from a proximal end to a distal end; a conductive cable fitting having first and second ends, a second connecting means at the second end for urging the fitting into connection with the terminal connector, the second end received within the bore; and a conductive cable fixed to the first end of the cable fitting. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate preferred embodiments which include the above-noted characteristics and features of the invention. The invention will be readily understood from the descriptions and from the drawings, in which: 
       FIG. 1  is a cross sectional view of a preferred battery terminal connection assembly shown in connection with a cable in accordance with the invention. 
       FIG. 2  is a perspective view of a preferred terminal connector in accordance with the invention. 
       FIG. 3  is a perspective view of a preferred cable fitting in accordance with the invention. 
       FIG. 4  is a perspective view of the preferred cable fitting of  FIG. 3  taken from line  4  in  FIG. 3  in accordance with the invention. 
       FIG. 5  is a perspective view of a preferred sleeve in accordance with the invention. 
       FIG. 6  is a perspective view of the preferred sleeve of  FIG. 5  taken from line  6  in  FIG. 5  in accordance with the invention. 
       FIG. 7  is a perspective view of a preferred battery terminal and cable connection arrangement in accordance with the invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , details of the battery terminal connection assembly  10  for connecting a battery terminal to a cable  50  will be set forth. The battery terminal connection assembly  10  includes a terminal connector  20  which has an arm  21  that is adapted to engage a battery terminal. Terminal connector  20  is preferably lead or another conductive material which is easily cast or otherwise formed. In preferred embodiments, the arm  21  forms an circular opening  22  which receives a battery terminal post. Terminal connector  20  also includes a hole  23  which extends from a proximal end  24  to a distal end  25 . 
   Received within and bonded to hole  23  is sleeve  30  which is formed from a cold-flow-resistant material such as copper, brass, bronze, or other alloys or materials which are conductive and which do not exhibit cold flow characteristics. Sleeve  30  is preferably tin-plated on its external side which contacts hole  23  to provide for maximum bonding between sleeve  30  and hole  23 . Sleeve  30  defines a bore  31  which further defines a bore axis  32 . Sleeve  30  also extends from proximal end  24  to distal end  25  and preferably includes a conical portion  26  in which the outer and inner diameters of sleeve  30  decrease from proximal end  24  to a position between proximal and distal ends  24 , 25 . Sleeve  30  further includes a non-circular portion  27  which prevents rotation between sleeve  30  and terminal connector  20  even under extreme stress. As is apparent from the FIGURES, the outer shape of sleeve  30  matches the shape of hole  23  such that sleeve  30  is completed bounded by and bonded to hole  23 . For instance, as shown, hole  23  includes a conical portion which matches conical portion  26  and a non-circular portion which matches non-circular portion  27 . 
   The battery terminal connection assembly  10  also includes a cable fitting  40  which extends from a first end  41  to a second end  42 . First end  41  is adapted to connect to cable  50  and second end  42  is adapted to be received within and connected to terminal connector  20 . As shown, first end  41  includes a recess  43  which receives cable  50 . Cable  50  can be welded, soldered or otherwise fixed to first end  41 . As shown, insulation  51  around cable  50  stops at first end  41  so that the conducting component of cable  50  is snugly received within recess  43 . 
   Cable fitting  40  preferably includes a conical portion  44  which corresponds to conical portion  26  of sleeve  30 . In other words, conical portion  44  mates with conical portion  26  such that connection between cable fitting  40  and terminal connector  20  occurs substantially along the entire surface of conical portion  44  which enters bore  31 . Cable fitting  40  also includes a engagement portion  45  which allows cable fitting  40  to be gripped, preferably by a wrench, while cable fitting  40  is fixed to terminal connector  20 . 
   Cable fitting  40  further includes a cavity  46  at second end  42  which provides for connection with tensioning member  60 . Cavity  46  is preferably threaded such that tensioning member  60  may be a threaded bolt which can be screwed into cavity  46  (while cable fitting  40  is gripped at engagement portion  45 ). Cavity  46  defines a cavity axis  47  which is aligned with bore axis  32 . 
   Tensioning member  60  includes a head  61 , a lock washer  63  and a washer  64  which cooperate to contact the distal end of terminal connector  20  adjacent bore  31 . Tensioning member  60  is connected to cable fitting  40  and draws cable fitting  40  into bore  31  until head  61 , lock washer  63  and/or washer  64  are in tight contact with terminal connector  20  such that tensioning member  60  can draw cable fitting  40  into bore no farther. Because sleeve  30  is cold-flow-resistant, the tight contact between cable fitting  40  and terminal connector  20  does not weaken and require further tensioning of the connection. 
     FIGS. 2-6  show perspective views of terminal connector  20 , cable fitting  40 , and sleeve  30 . As can be seen bore  31  and opening  22  are relatively positioned such that bore axis  32  and opening axis  28  are skew (they do not intersect and lie in different planes). Preferably, when opening axis  28  is vertical the bore axis  32  is horizontal. 
   Sleeve  30  is shown more clearly shifting from a circular and conical portion  26  to a non-circular portion  27 . Thickness of sleeve  30  is preferably substantially constant such that conical portion  26  and non-circular portion  27  are exhibited in both the outer surface and inner surface of sleeve  30 . 
     FIG. 7  depicts a preferred battery terminal and cable connection arrangement  16  in which battery  12  includes a terminal  14  in the form of a terminal post. Terminal  14  is received within the opening formed by arm  21 . Arrangement  16  provides for durable connection between cable  50  and battery terminal  14 . 
   While the invention has been described with respect to specific embodiments by way of illustration, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true scope and spirit of the invention.