Patent Publication Number: US-5839924-A

Title: Battery connector with conductive coating

Description:
This application is a continuation-in-part of U.S. application Ser. No. 08/414,419 filed Apr. 3, 1995 entitled BATTERY CONNECTOR, now U.S. Pat. No. 5,586,919. 
    
    
     BACKGROUND OF THE INVENTION 
     Automobile-type batteries have use in many applications today. Some of the places automobile-type batteries are found include cars, trucks, boats, riding lawn mowers, golf carts and other recreational vehicles and to perform a wide variety of functions, from starting the automobile, boat or lawn mower to running accessories, such as lights, radios televisions and car phones. In addition, contractors use this type of battery in their various equipment. 
     Many times it becomes necessary to frequently remove the battery or to disconnect one of the terminals to break the current and prevent battery drain during extended periods of nonuse. Once such instance arises in marine applications where drained batteries are continually being removed in order to be recharged and freshly charged batteries are being installed. Another instance is winter in the northern portion of the continental United States, Canada and Alaska when the temperature drops below the point where the battery will not function properly. Conventional battery connectors are cumbersome and slow to put on or release from the generally cylindrical battery post. Further, since most connectors are made from soft lead, the constant opening and closing of the connector has a tendency to weaken the connector and cracks may form in the connector. 
     The prior art includes apparatus that uses a nut and a bolt as the means for holding the connector onto the associated battery post. Traditional connectors are made from soft lead and the nut and the bolt squeeze the two opposite sides together against the associated battery post, thereby making good electrical contact in addition to holding the connector onto the associated battery post. Some newer connectors are shaped similar to the traditional soft lead connectors and also use a nut and a bolt to hold the connector onto the associated battery post, but are made from other electro-conductive metals. 
     It is an object of the invention to provide apparatus that is easy to put on and release from a generally cylindrical battery post. 
     Yet another object of the invention is to provide apparatus that is easily biased from an open position to a closed position and from a closed position to an open position without the aid of tools. 
     Still another object of the invention is to provide apparatus that is reliable and durable to withstand the frequent movement between the open position and the closed position. 
     It is also an object of the invention to provide apparatus which is inexpensive to manufacture as well as require a minimum of labor to install. 
     Yet still another object of the invention is to provide a connector which is coated with a material making it more electrically conductive and resistant to corrosion. Another object of the invention is to provide apparatus that will fit on the posts of almost any brand of automobile battery. 
     SUMMARY OF THE INVENTION 
     It has now been found that these and other objects of the invention may be found in a connector for quickly clamping onto and releasing from an associated generally cylindrical battery post. The apparatus includes a unitary metallic body having first and second elongated portions disposed in generally parallel spaced relationship with the first and second elongated portions having respective first and second cylindrical section shaped portions disposed therein in opposed relationship. The apparatus also includes means for biasing the first and second opposed cylindrical section shaped portions toward each other, whereby good electrical contact is made with the associated generally cylindrical battery post. The apparatus also includes means for forcing the first and second opposed cylindrical section shaped portions apart, whereby the connector may easily be removed from the associated battery post. 
     In some forms of the invention, the means for forcing the first and second opposed cylindrical section shaped portions apart includes means disposed intermediate the first and second elongated portions which is movable between a first position which does not cause the first and second elongated portions to move apart and a second position which does cause the first and second elongated portions to move apart. 
     In some forms of the invention, the means for forcing the first and second opposed cylindrical section shaped portions apart may be generally oblong in cross-section, whereby the distance across the cross-section thereof is substantially greater in a first direction than in a second direction. Movement of the means for forcing the first and second opposed cylindrical section shaped portions to a position where the first direction is substantially perpendicular to the first and second elongated portions will tend to move the first and second elongated portions apart and movement of the means for forcing the first and second opposed cylindrical section shaped portions to a position where the second direction is substantially parallel to the first and second elongated portions will tend to allow the first and second elongated portions to move toward each other. 
     The apparatus may also include means for biasing provided by the temper of the material from which the unitary metallic body is manufactured. 
     The apparatus may also include opposed portions having third and fourth generally arcuate opposed faces and the oblong member maybe disposed between the third and fourth generally arcuate opposed faces. 
     The structure of the body portion is comprised solely of a strip of sheet metal configured to create opposed partially cylindrical section shapes with juxtaposed free ends normally inwardly biassed in compression towards one another for clamping about a substantially cylindric battery post. The structure of the body portion further being configured in the region of each the free end to receive a means for moving apart through rotation the normally inwardly biassed partially cylindrical section shapes from one another from an otherwise compressing condition about a battery post and wherein the strip of sheet metal being coated with a thin layer of electrically conductive corrosion resistant material. 
     The invention further resides in a method of connecting a battery cable to an associated battery terminal comprising the steps of providing a piece of sheet metal; stamping the sheet metal to form a strip which is substantially T-shaped as defined by an elongate portion and a tab portion; bending the elongate portion of the stamped T-shaped metal strip to form partially cylindric sections which are biassed toward one another by the bending in the sheet material; coating the partially cylindric sections with a thin layer of an electrically conductive corrosion resistant material, spreading the coated opposed partially cylindric sections apart from an initial compressed condition to surround a battery terminal post, and thereafter releasing the otherwise spread partially cylindrical sections so as to clamp the connector about the battery terminal post; and connecting a cable to the connector by using the tab portion of the T-shaped strip to conduct electricity between the cable and a battery post terminal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention will be better understood by reference to the accompanying drawing in which: 
     FIG. 1a is a top view of a sheet of metal with multiple T-shaped stamping and FIG. 1b is a top view of a T-shaped metal piece before it is bent into the unitary metallic body. 
     FIG. 2a is a top view illustrating the connector in an open position. FIG. 2b is a top view illustrating the connector in a closed position. 
     FIG. 3 is a fragmentary side elevational view of the connector in a closed position. 
     FIG. 4 is a fragmentary rear elevational view of the means for joining the connector to the associated cable. 
     FIG. 5 is a side elevational view of the connector in a closed position on the generally cylindrical battery post. 
     FIG. 6 is an alternative embodiment of the device showing formed microridges. 
     FIG. 7 is an alternate embodiment of the tab. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIGS. 1-5 there is shown a preferred form of the connector apparatus 10 for quickly clamping onto and releasing from an associated battery post 11 in accordance with a preferred form of the invention. The connector apparatus 10 includes a unitary metallic body 8 having a first elongated portion 12 and a second elongated portion 14 disposed in generally parallel spaced relationship. The first elongated portion 12 has a cylindrical section shaped portion 22 and the second elongated portion 14 has a cylindrical section shaped portion 24. The cylindrical section shaped portions 22 and 24 are disposed in an opposed relationship. The elongated section 12 contains a generally arcuate face 26 and the elongated section 14 contains a generally arcuate face 28 with the generally arcuate face 26 opposite the generally arcuate face 28. The relationship of the elongated portions 12 and 14, the cylindrical section shaped portions 22 and 24, and the generally arcuate faces 26 and 26 in the unitary metallic body 8 are illustrated in great detail in FIGS. 2a and 2b. 
     An oblong member 16 having rounded edges 30 and 32 is disposed between the generally arcuate faces 26 and 28 of the elongated portions 12 and 14. The rounded edges 30 and 32 are parallel to the associated battery post 11. The oblong member 16 is movable between a first position which does not cause the elongated portions 12 and 14 to move apart and a second position which does cause the elongated portions 12 and 14 to move apart, enabling the connector apparatus 10 to be released from the associated battery post 11. In the first position, the oblong member 16 is generally parallel to the elongated portions 12 and 14 while in the second position the oblong member 16 is generally perpendicular to the elongated portions 12 and 14. The rounded edges 30 and 32 mate with the generally arcuate faces 26 and 28 when the oblong member 16 is in the second position. The oblong member 16 is constructed from a nylon material but other materials such as other plastics or various metals may be used. The second position is illustrated in FIG. 2a and the first position is illustrated in FIGS. 2b, 3 and 5. 
     In certain circumstances, the oblong member 16 may cause interference by being taller than the associated battery post 11. The connector apparatus 10 may be constructed so that the rounded ends 30 and 32 of oblong member 16 are perpendicular to the associated battery post 11. The oblong member 16 is disposed between the generally arcuate faces 26 and 28 of the elongated portions 12 and 14. In this configuration, the oppositely disposed generally arcuate faces 26 and 28 extend partially through the length of the elongated portions 12 and 14. 
     The unitary metallic body 8 contains a tab 20 which is used to connect the unitary metallic body 8 to the associated cable 18. The tab 20 is in alignment with the oblong member 16 when the oblong member 16 is in the first position. The ends of tab 20 wrap around the bare wire of the associated cable 18 to form a good electrical connection. This is shown in great detail in FIG. 4. Tab 20 and the associated cable 18 are also shown in FIGS. 2a, 2b, 3 and 5. Alternatively as seen in FIG. 7 at element 60, the tab may be formed with a depression for receiving a cable therein, with a top bracket 62 being provided to mount to the tab in order to compress the cable within the depression. 
     In many batteries today, the associated positive battery post 11 and the associated negative battery post 11 differ in diameter. In addition, the associated battery post 11 is slightly tapered with the diameter of the base slightly larger than the diameter of the top. The cylindrical section shaped portions 22 and 24 are canted to conform to the taper of the standard battery terminal 11. The canted cylindrical section shaped portions 22 and 24 encircle the associated battery post 11 when the oblong member 16 is generally parallel to the elongated portions 12 and 14. The canted cylindrical section shaped portions 22 and 24 allow for good electrical contact on either the associated positive battery post 11 or the associated negative battery post 11. The unitary metallic body 8 is stamped from a single sheet of metal 6 and then bent into shape. FIG. 1a illustrates the multiple stamping of unitary metallic bodies 8 in a single sheet of metal 6. The unitary metallic body 8 can be manufactured from any metal that meets the requirements of electroconductivity and temper of the material that allows the unitary metallic body 8 to spring back and forth. The thickness of the unitary metallic body 8 will vary for the specific application. The material for manufacturing the unitary metallic body 8 may be a hard steel or stainless steel, such as 400 series, or Inconel 60 Type or phosphorous bronze or steel with inlays such as copper, lead or stainless steel or the like. The unitary metallic body 8, after it is stamped from the sheet of metal 6, is T-shaped and is bent to form the elongated portions 12 and 14, the cylindrical section shaped portions 22 and 24, the generally arcuate faces 26 and 28 and the tab 20. FIG. 1b illustrates the unitary metallic body 8 after it is stamped from the sheet of metal 6 and before it is bent. 
     Each battery will differ in size depending on its designed use. For example, an automobile battery used in cars and trucks is smaller than a recreational vehicle battery. A battery for marine use differs in size from automobile batteries. Since the battery sizes differ, the battery terminals 11 differ in diameter. Also, with changes in battery size, it should be understood that the thickness of the stamped material 6 also will vary to accommodate carrying the different currents attendant to the different battery sizes. The connector apparatus 10 is manufactured in various sizes so that when the cylindrical section shaped portions 22 and 24 encircle the terminal 11, the cylindrical section shaped portions 22 and 24 conform to the diameter of the terminal 11, thereby making good electrical contact. Each size battery will have a respective connector apparatus 10. Although the connector apparatus 10 has been described as a single unit to be attached to an associated cable 18, it is envisioned that the connector apparatus 10 and cable 18 will be packaged and sold as a single unit. 
     Another aspect of the invention is to provide a battery connector of the aforementioned type wherein the single metal or substrate material surface 50 forming the device is coated at least in part with a thin film of a electrically conducting corrosion resistant material 52. That is, at minimum, the partially cylindric sections are covered with the thin layer of electrically conductive corrosion resistant material. The below listed table sets forth various types of coatings which are applicable to a connector formed preferably from steel as described above as well as listing typical layer thickness which would be suitable for such application. 
     
                       TABLE I                                                     
______________________________________                                    
COATING BY ELECTROPLATING                                                 
          ELECTRO RES.   THICKNESS                                        
COATING   microhlms-cm   mil.                                             
______________________________________                                    
Rhodium    4.7           0.001-1.0                                        
Silver     1.5           0.1 (with undercoat to                           
                         1.0)                                             
Tin       11.5           0.015-0.5                                        
Zinc       5.8           0.1-0.5 (light duty),                            
                         0.5-2 (outdoors)                                 
Copper-Tin                                                                
          --             0.5                                              
(Bronze)                                                                  
Copper-Zinc                                                               
          --             0.1-1.0                                          
(Brass)                                                                   
Lead-Tin  --             0.2                                              
Tin-Nickel                                                                
          --             0.2-0.6                                          
Tin-Zinc  --             0.15-0.30                                        
______________________________________                                    
 
    
     
                       TABLE II                                                    
______________________________________                                    
COATING BY CHEMICAL IMMERSION                                             
COATING    IMPORTANT PROPERTIES                                           
                             THICKNESS                                    
______________________________________                                    
(Electroless)                                                             
           Because of amorphous                                           
                             From 1-5.0                                   
Nickel     structure and phosphorus                                       
                             mils,                                        
           content (B-10%), these                                         
                             depending on                                 
           coating have better                                            
                             end use                                      
           abrasion resistance than                                       
           electrolytic or wrought                                        
           nickel                                                         
Tin        Offers short-term Decorative:                                  
           solderable surfaces, some                                      
                             0.015 mil;                                   
           corrosion protection and                                       
                             heavy duty:                                  
           ease of application at                                         
                             up to 2.0                                    
           low cost          mils                                         
Copper     High electrical   From 0.04-1.0                                
           conductivity, good                                             
                             mil                                          
           lubrication properties                                         
Gold       Good electrical   Usually about                                
           conductivity and  0.01-0.04 mil                                
           emissivity, bright,                                            
           attractive appearance                                          
Silver     Bright, attractive                                             
                             Usually about                                
           appearance        0.001 mil,                                   
                             but sometimes                                
                             as high as                                   
                             0.03 mil                                     
______________________________________                                    
 
    
     In addition to the above, coating of the metallic body 8 may be accomplished by hot dipping the body 8 into a molted bath of aluminum, tin, or terne. 
     Referring now to FIG. 6, it is a further feature of the invention to provide microridges 56,56 on the inner surfaces 58,58 of the arcuate faces 26 and 28 which extend posts and to prevent unwanted vertical movement. These microridges may be formed at the time of stamping by etching, cutting or stamping, or may cut into the sheet material of the body portion in a post stamping process by using a tap screw threading method. 
     The invention has been described with reference to its illustrated preferred embodiment. Persons skilled in the art of such devices may upon exposure to the teachings herein, conceive other variations. For example, it is entirely within the purview of the invention to use a horizontally disposed member 16 to effect separation of the portions 22 and 24. Such variations are deemed to be encompassed by the disclosure, the invention being delimited only by the following claims.