The present application is related to Provisional Patent Application entitled “Compact Battery Clamp,” filed 20 Nov. 2012 and assigned filing No. 61/728,738, incorporated herein by reference in its entirety.
This invention relates to a device for providing a method of electrically connecting to the terminals of a battery and, in particular, a device for enabling quick and convenient electrical connection to the terminals of a lead-acid battery.
Battery cables, or booster cables, such as used in “jump starting” a vehicle, have been known in the art for some years. A set of booster cables typically includes a six-foot length of a two insulated electrical conductors of sufficient gauge to safely conduct starting current amperage. Four booster clamps, or battery clamps, resembling clothes pins and referred to as “crocodile clips,” are provided at respective ends of the booster cable electrical conductor pair so as to electrically couple either two batteries, or one battery and a battery charger.
A conventional booster cable configures the battery clamps with serrated jaw ends to make mechanical and electrical contact with: (i) battery terminals or posts, if the battery is not installed in a vehicle, or (ii) vehicle battery cable terminals, if the battery is installed in a vehicle with the vehicle battery cable terminals secured onto the battery posts or terminals. The battery clamps are spring-loaded to force the clamp jaw serrations against the battery post or against the vehicle battery cable terminals, so as to provide a positive electrical connection to the respective battery post or to the vehicle battery cable terminal.
However, conventional battery clamps suffer from the shortcoming that the serrated ends of the battery clamps, typically made from copper or a copper alloy, cause indentations and other surface damage to the battery posts or vehicle cable terminals, which are typically made from lead—a softer metal than copper. Over time, the appearance and effectiveness of the battery posts or the vehicle cable terminals may suffer from repeated attachment of the booster cable.
Another shortcoming is that one of the battery clamps may be accidentally dropped into the vehicle chassis or engine compartment when a user is in the process of connecting or disconnecting the booster cable from a battery. If the vehicle is a negative-ground system, and it is the negative battery clamp that is dropped, a short circuit may result by conducting electrical current from the positive battery terminal into the chassis or engine components, and back into the battery, producing electrical arcing or sparking, and possibly igniting hydrogen gas being expelled from the charging battery.
A further shortcoming is that the connection of the booster cable to the battery typically requires using both hands to hold apart the booster clamps when securing the booster cable to the battery so as to not short out a battery connected to the other end of the booster cable. What is needed is a battery clamp configuration that overcomes the limitations of the prior art by providing a method to secure a booster cable to a battery without causing surface damage to lead-based components, while providing a good electrical contact, and which requires only one hand to attach or to remove the booster cable from a battery.
In one aspect of the present invention, a compact battery clamp suitable for attachment to a high-amperage, two-conductor, insulated electrical cable, the compact battery clamp comprising: a clamp handle having a first clamp handle end and a second clamp handle end; a contact arm having a first contact arm end and a second contact arm end; a pivot pin passing through the clamp handle and through the first contact arm end so as to hingedly connect the contact arm to the clamp handle; a first terminal contact pad rotatably attached to the first clamp handle end; a second terminal contact pad rotatably attached to the second contact arm end; and an electrical socket attached to the second clamp handle end, the electrical socket configured for electrically coupling with an end of the insulated electrical cable.
In another aspect of the present invention, a booster cable suitable for use in charging a first battery with a second battery comprises: a two-conductor, insulated electrical cable; a first battery clamp electrically attached to a first end of the two-conductor, insulated electrical cable, the first battery clamp including a first contact arm hingedly connected to a first clamp handle, the first battery clamp generally configured in a lambda shape; and a second battery clamp electrically attached to a second end of the two-conductor, insulated electrical cable, the second battery clamp including a second contact arm hingedly connected to a second clamp handle, the second battery clamp generally configured in a lambda shape.
In still another aspect of the present invention, a method for electrically attaching a two-conductor electrical cable to battery posts, the method comprising the steps of: providing a first terminal contact pad; providing a second terminal contact pad; forcing the first terminal contact pad against a first battery terminal, and forcing the second terminal contact pad against a second battery terminal.
The additional features and advantage of the disclosed invention is set forth in the detailed description which follows, and will be apparent to those skilled in the art from the description or recognized by practicing the invention as described, together with the claims and appended drawings.
The uses and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when viewed in conjunction with the accompanying figures, in which:
There is shown in
When in use, a user may grasp the upper portion of the clamp handle 12, and position the compact battery clamp 10 between the terminals 22 and 24 of a battery 20, substantially as shown. The compact battery clamp 10 is configured so as to maintain electrical contact with both the terminals 22 and 24 after the clamp handle 12 has been moved downwardly, towards the battery 20, as shown in
The clamp handle 12 may include a first terminal contact pad 32 rotatably attached to a first end of the clamp handle 12 by means of a first swivel connector 34. The first swivel connector 34 provides the terminal contact pad 32 with at least two degrees of freedom with respect to the clamp handle 12, so that the terminal contact pad 32 can be optimally swiveled and positioned against the battery terminal 24 to maximize the extent of a physical contact area. It should be understood that the contact pad may optimally position against the battery terminal 24 without requiring any adjustment from the user.
The contact arm 14 similarly includes a second terminal contact pad 36 rotatably attached to a second end of the contact arm 14 by means of a second swivel connector 38. In an exemplary embodiment, the swivel connectors 34 and 38 may each comprise a ball and socket connector pair, as known in the relevant art. This swiveling feature optimizes the area of electrical contact of the compact battery clamp 10 with the battery terminals 22 and 24, and results in a minimal voltage drop across the respective contact interfaces. It should be understood that the particular terminal contact pads 32 and 34 shown are merely exemplary of electrical connection devices that may be used at the first end of the clamp handle 12 and at the end of the contact arm 14, and that any suitable electrical contact component may be used to perform the same functions as the terminal contact pads 32 and 34.
Accordingly, when in an “open” position, shown in
When in a “closed” position, shown in
In an exemplary embodiment, the compact battery clamp 10 can be configured so that an open space is defined between the battery 20 and the underside of the compact battery clamp 10, here indicated as dimension “D.” The empty space may be desired to provide clearance for a battery retaining strap, a bracket, or a battery vent cover disposed on the surface of the battery 20 after the compact battery clamp 10 has been placed into the extended configuration.
In an exemplary embodiment, the clamp handle 12 can be releasably secured in the closed position by means of a U-spring clamp 42. By lowering the clamp handle 12 onto the contact arm 14, as shown in
Additionally, the selection of spring material used for the U-spring clamp 42 may produce a spring constant of sufficiently large value that the compressive force induced by the arms of the U-spring clamp 42 onto the sides of the contact arm 14 results in enough surface static friction to mitigate relative movement of the clamp handle 12 with respect to the contact arm 14. In an alternative embodiment, the contact arm 14 may include a pair of dimple features (not shown) sized and positioned on the outer surface if the contact arm 14 so as to more positively engage and retain the free ends of the U-spring clamp 42, as is well-known in the relevant art. In an alternative embodiment (not shown), the upper portion of the clamp handle 12 may be slightly curved away from the contact arm 14 so as to provide additional clearance between the upper portion of the clamp handle 12 and the battery 20 to more easily accommodate the hand of the user.
As explained above, the U-spring clamp 42 is configured to enclose and frictionally remain in position on the contact arm 14, and thus functions to restrain the clamp handle 12 from moving off the contact arm 14. The compact battery clamp 10 is, in this manner, maintained in a state of compression between the battery terminals 22 and 24 when the battery clamp 10 is emplaced for use as intended. As can be appreciated by one skilled in the art, this state of compression serves to increase the electrical conductivity at the interfaces between the battery terminals 22 and the terminal contact pads 32 and 36 of the compact battery clamp 10. In an exemplary embodiment, the U-spring clamp 42 may be re-positioned along the clamp handle 12 by a sliding motion, to change the distance from the pivot pin 16 as desired, the distance here indicated as dimension “C.” In an alternative embodiment, the
The thickness of the contact body 44 is preferably greater than the thickness of the terminal contact foil 46. Alternatively, the rigidity of the contact body 44 is preferably greater than the rigidity of the terminal contact foil 46. This configuration allows the terminal contact foil 46 to assume a generally curved shape, approximating the convex circumferential surface of the battery terminal 22, when forced against the battery terminal 22. This configuration also serves to return the terminal contact foil 46 to a generally planar shape when the terminal contact pad 36 is moved away from the battery terminal 22, as shown in
It can thus be appreciated that the legs of the terminal contact body 44 are slightly bent inwardly when the terminal contact pad 36 is forced against the battery terminal 22, and spring back when the terminal contact pad 36 is removed from the battery terminal 22. By enabling the terminal contact foil 46 to partially wrap about the battery terminal 22, when the compact battery clamp 10 is placed into a state of tension, a greater contact area is achieved with the battery terminal 22, than if the terminal contact foil 46 remained flat, or if the terminal contact pad 36 were fabricated as a single, rigid component.
This configuration also allows for use of the compact battery clamp 10 when a vehicle battery cable clamp 48 is attached to either or both the battery terminals 22 and 24, such as may be the case when the battery 20 is mounted in a vehicle engine compartment. It can be appreciated by one skilled in the relevant art that the vehicle battery cable clamp 48 has a larger diameter than the battery terminal 22 and, because of flexibility of the terminal contact foil 46, the terminal contact foil 46 can partially wrap around both the battery cable clamp 48 and the battery terminal 22 so as to increase the area of physical and electrical contact. The compact battery clamp 10 can thus be used in the process of charging the battery 20 (i) when the battery 20 has been removed from a vehicle and placed on a bench, or (ii) when the battery 20 remains secured in an engine compartment and is electrically connected to a pair of vehicle battery cable clamps 48.
In an alternative exemplary embodiment, a terminal contact pad 50, shown in
The terminal contact cup 52 is sized and shaped so as to generally conform to: (i) the outer surface contour of the battery terminal 20, as shown in
As can be appreciated, the contact cup 52 may be too inflexible to usefully conform to the outer contour of the battery terminal 22 or to the outer contour of the battery cable clamp 48. Consequently, electrical resistance is thereby reduced between the terminal contact pad 50 and the battery terminal 22, and between the terminal contact pad 50 and the battery cable clamp 48. In addition, the terminal contact cup 52 may be mounted to the swivel connector 38 for the reasons stated above.
As shown in
As the electrical cables 28 can be attached or removed as desired, the combination of two compact battery clamps 10 and the pair of electrical cables 28 provide for a booster cable assembly 150, shown in
As best seen in
As also seen in
It can thus be appreciated by one skilled in the art that a first electrical path runs from the electrical connector 72, through the third electrical conductor 66, through the swivel connector 34, through the terminal contact pad 32, and to the battery terminal 24. A second electrical path runs from the electrical connector 74, through both the first electrical conductor 62 and the second electrical conductor 64, through the pivot pin 16, through the contact arm 14, through the swivel connector 38, through the terminal contact pad 36, and to the battery terminal 22. In an exemplary embodiment, an insulating layer 70 may be provided on the surface of the clamp handle 12 to reduce the risk of electrical shorts during emplacement and positioning of the compact battery clamp 10 between the battery terminals 22 and 24, and near protruding metal components, such as may be found in the engine compartment of a motorized vehicle.
As also shown in the cross-sectional view of
Accordingly, in the alternative embodiment, the combination of the clamp handle 12 and the U-spring clamp 42 may be replaced by a clamp handle 80 comprising interior concave recesses 82 and 84, as shown, for retention of the tubular contact arm 88. When the clamp handle 80 is pushed towards the tubular control arm 88, the tubular control arm 88 may enter the clamp handle 80 and engage both the recesses 82 and 84. This can function to place the corresponding clamp handle 12 into a state of compression between battery terminals or vehicle battery cable clamps, as explained in greater detail above.
It should be understood that the configuration of the mating socket openings in the electrical socket 60 is not limited to any one particular geometric shape. As shown in
In an exemplary alternative embodiment, shown in
In yet another exemplary alternative embodiment, shown in
In an exemplary embodiment, shown in
The adjustment feature may include an internal thread 148 formed in the lower tubular member 144, and an external thread 149 formed on the upper cylindrical member 146, for example. That is, the lower tubular member 144 thus has a threaded interface with the upper cylindrical member 146. The upper cylindrical member 146 may comprise a solid rod, or a hollow tube, as may be specified by a product designer. Alternatively, a chuck-like configuration (not shown) can be included on the upper end of the lower tubular member 144, to enable a sliding adjustment of the upper cylindrical member 146 into and out of the lower tubular member 144.
There is shown in
For clarity of illustration, the booster cable 150 is shown attached to the battery posts of the batteries 20 and 26, but it should be understood that the compact battery clamps 10 may be used as well when vehicle battery cable terminals remain emplaced on the battery posts of one or both batteries 20, 26. In an alternative embodiment, one or two compact battery clamps 140 (not shown) may be used in place of one or both the compact battery clamps 10, at respective ends of the high-amperage, two-conductor, insulated electrical cable 28, in accordance with the present invention.
It is to be understood that the description herein is only exemplary of the invention, and is intended to provide an overview for the understanding of the nature and character of the disclosed booster cable and battery clamp configurations. The accompanying drawings are included to provide a further understanding of various features and embodiments of the method and devices of the invention which, together with their description and claims serve to explain the principles and operation of the invention.
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Number | Date | Country | |
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Number | Date | Country | |
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61728738 | Nov 2012 | US |