Battery terminal and method for making the same

Abstract

A battery terminal is configured to be secured to a battery case and includes a terminal assembly, and a ring. The terminal assembly includes an insert having a threaded bore, and an outer metal portion having a base with an annular flange configured to engage the inner surface of the case. The terminal further includes an anti-turn system with a first set of angularly-spaced bosses with intervening slots formed on a boss on the case, a second set of angularly-spaced bosses with intervening slots on a first side of the ring facing the case, which are complementary to the first set to form interlocking features. A set of recesses on the opposite side of the ring is configured to receive spun-over lead material during final finishing to form another pair of interlocking features. The exterior spun battery terminal eliminates corrosion that would otherwise occur due to cold worked lead contacting acid.

Description

BACKGROUND OF THE INVENTION [0001] 1. Technical Field [0002] The present invention relates generally to a battery terminal and a method for making the same. [0003] 2. Description of the Related Art [0004] It is known generally to provide an electric storage battery of the type having external terminals on the side or end walls of the battery case. Typically, such terminals are not of the post type, but rather are of the recessed, threaded female type terminal, as seen by reference to U.S. Pat. No. 5,814,421 to Spiegelberg et al. Spiegelberg et al. disclose a method for forming such a battery terminal having a threaded hard metal insert received within an outer portion formed of lead, the lead portion being deformed (i.e., cold worked) by an orbital head-forming apparatus to secure the hard metal insert within the outer lead portion. Spiegelberg et al. further disclose that the outer portion includes a spline ring to prevent rotation of the terminal within the battery housing. Spiege...

AI Technical Summary

Benefits of technology

[0007] One advantage of the present invention is that it provides an exterior (i.e., on the outside of the battery case) spin riveted terminal to eliminate the interior (i.e., interior of the battery case) lead cold working to thereby minimize corrosion as described in the Background, and the accompanying leakage associated therewith. Another advantage of the present invention is that it provides an anti-rotation arrangement of interlocking bosses / slots that provide a torque-turning resistance that is improved over conventional approaches taken in the art. Another advantage of the present invention is that it provides a battery terminal having a sealing system configured to seal the battery terminal area to thereby minimize or prevent leakage of fluid, such as sulfuric acid solution. Still another advantage according to the present invention is that it provides a battery terminal having a mechanism for minimizing or eliminating acid stratification, which minimizes corrosion (as described in greater detail hereinafter).

[0008] A battery terminal according to the invention is configured to be secured to a battery case from an exterior side thereof. The battery terminal comprises a terminal assembly, a ring, and a terminal anti-rotation system. The terminal assembly extends generally along a main axis and includes (i) an insert having a threaded bore and (ii) an outer metal portion having a base with an annular flange configured to engage an inner surface of the case. The terminal assembly is inserted from the inside of the case. The ring is configured to be disposed over the terminal assembly from the exterior of the case. The anti-rotation system includes a first set of angularly-spaced bosses with intervening slots formed on a case boss on an outer surface of the battery case. The anti-rotation system further includes a second set of angularly-spaced bosses with intervening slots on a first side of the ring that faces the case boss when inserted over the terminal assembly. The second set of bosses / slots are complementary with the first set to form a first pair of interlocking features. The anti-rotation system also includes a set of recesses on a second side of the ring opposite the first side configured to receive portions of the terminal assembly that are subsequently deformed into such recesses.

[0009] In a preferred embodiment, the portions of the terminal assembly to be received into the set of recesses comprise the distal end portions of the terminal assembly which are, at least in part, deformed in accordance with an orbital spin cold-working operation. A second preferred embodiment is also presented wherein the terminal assembly and the ring are joined using a welding operation.

[0010] In a still further embodiment, the battery terminal further includes (i) an inventive sealing system and (ii) radial bores that allow acid solution to communicate between the main interior of the case and an interior seal which is located in an annular groove.

Problems solved by technology

The anti-rotation approach in Spiegelberg et al., however, does not provide satisfactory resistance to rotation in certain circumstances and the sealing approach requires a complicated insert molding process or the like.

However, it has been found that the cold worked lead, which is exposed to acid (e.g., sulfuric acid solution in a lead-acid battery), results in accelerated corrosion, which may result in acid solution leaking out of the battery case in and around the terminal area.

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