Battery clamp

Abstract: A battery clamp (1) for connection of electrical cables to a terminal post of an electric storage battery has a body (2) of electrically conductive material with an aperture formed therethrough to accommodate the terminal post and includes cam operated locking means (6 and 7) for releasably securing the clamp to the post and also means for releasably securing at least one electric cable to the clamp. Also disclosed is a cam operated electrical cable connector (21) for use with the battery clamp or a suitably adapted cable adaptor (41).

Description: This invention relates to clamps for electric storage batteries and to cable connectors used in conjunction therewith. An application is described for motor vehicle batteries but the invention is not exclusively confined thereto. Battery clamps for securing electrical leads to the terminal posts of motor vehicle batteries generally have securing means comprising an "U" shaped body having a bolt passing through the legs and secured by a nut on the threaded end of the bolt. This system suffers from the disadvantage of requiring a spanner of the correct size to connect or disconnect the clamp and further, the bolt being of a corrosive material, tends to corrode, resulting in difficulty in removal and possible damage to the clamps or terminal post. Although other types of clamp have been used, eg a spring release clamp, these suffer from one or other of these disadvantages, resulting in delays when connecting or disconnecting batteries in service. EP 0164462 discloses a battery connector in which a locking ring is provided loose between two fixed rings. The fixed rings include a cable connector. The rings have openings to receive a battery post through all three rings. The opening in the locking ring is offset from the openings in the fixed rings and the locking ring includes integral lugs to engage the outer circumferential surfaces of the fixed rings so that a cam is formed. It is an object of this invention to provide a clamp which is of simple construction and allows for quick release and securement of battery cables to a battery and also provides quick release cable connectors. According to the invention there is provided a battery clamp for the connection of electrical cables to a terminal post of an electric storage battery comprising a body of electrically conductive material, the body including means for securing at least one electric cable to the clamp, an aperture therethrough to accommodate said terminal post and locking means whereby the clamp may be releasably secured to the terminal post; characterised in that the locking means is located in a recess in the body communicating with the aperture and comprises a rotatable offset cam and a follower in the form of a slug slidable in the recess into and away from the aperture, whereby the cam is arranged to act against the follower to offset the follower relative to the body, such that upon rotation of the cam the follower is lockable into electrical contact with a battery terminal post accommodated by the aperture, the slug having a first surface which is complementary to the shape of a terminal post and a second surface which is complementary to the cam to provide an extensive area of contact with both the cam and the post when locked. Further preferred features, the electrically conductive material body is preferably a casting of elongate configuration. Still further, preferably, the means for releasably securing an electrical cable to the clamp comprises a socket in the body adapted for the insertion and locking therein of a spigot of an electrical connector to which the cable is secured, the spigot having a cam formation thereon whereby the connector may be locked into electrical contact with the clamp. Still further, preferably the body includes an insulating cover surround adapted to provide openings therethrough for a terminal post, electrical connections and an adjusting boss of the cam operated locking means. Two embodiments of the invention are described below by way of example only and with reference to the accompanying drawings in which: Fig. 1 shows a battery clamp according to the invention in plan and cross section; Fig. 2 shows an elevation and plan of a cam connector according to the invention; Fig. 3 shows a battery clamp according to the invention incorporating two removable cam connectors of the type illustrated in Fig. 2. There now follows a detailed description of two preferred embodiments of the invention with reference to the drawings. As illustrated in Fig. 1, there is provided a battery clamp (1) for use in connecting a high tension cable to one of the battery posts of a motor car battery which comprises a cast metal body (2) of oblong shape, enclosed in a plastic cover (3), and having an aperture (4) therethrough shaped to co-operate with the terminal post over which it is located in use. Formed in the body (2) is a shaped recess (5) in which is located an offset cam (6) adjacent to and spaced from a cam slug (7) which is cast from an electrically conductive material and, more particularly an aluminium alloy, and shaped to be locked by the cam in use against the terminal post and integral with the cam (6) is a boss (8) which projects through the top of the plastic cover (3). In the face of the boss (8) is a slot (9) into which a screw driver may be inserted for adjustment of the cam. In the end (10) of the body remote from the aperture (4) is a short bore (11) for insertion of a high tension cable. In use the clamp (1), with a cable inserted in the bore (11) and secured to the body (2) by means of a grub screw (12) passing through a tapped bore therein, is placed with aperture (4) located over a terminal post of a battery. The cam (6) is turned by a screwdriver or like instrument inserted in the slot (9) of the boss (8) to force the slug (7) into locking engagement with the terminal post. Figure 2 illustrates a cam connector (21) which comprises an aluminium casting part (22) which is of hexagonal shape with a short bore (23) open at one end into which a cable may be inserted and secured in the connector by a grub screw (24) and a spigot end (25) on which is carried an offset cam (26). Now referring to Figure 3, a second embodiment of the invention is illustrated which incorporates cam connectors of the type shown in Figure 2. In this embodiment, a battery clamp (31) similar to that of the first embodiment is provided, having two cam connectors (21) secured in locked position within two sockets (33) formed in the body (34) of the clamp, the sockets being formed to cooperate with the cams of the connectors. Like items of clamp (31) with that of the first embodiment are referenced as in Figure 1. In this embodiment it will be seen that two cables may be connected to a clamp on one terminal post. It will be seen that the invention provides ease of connection and disconnection for battery clamps when maintenance is carried out and that other embodiments of the invention are envisaged for the connection of cables when, for example, a battery charger is to be used.

Claims: A battery clamp (1) for the connection of electrical cables to a terminal post of an electric storage battery comprising a body (2) of electrically conductive material, the body including means (12) for securing at least one electric cable to the clamp, an aperture (4) therethrough to accommodate said terminal post and locking means whereby the clamp may be releasably secured to the terminal post; characterised in that the locking means is located in a recess (5) in the body communicating with the aperture (4) and comprises a rotatable offset cam (6) and a follower (7) in the form of a slug slidable in the recess (5) into and away from the aperture, whereby the cam is arranged to act against the follower to offset the follower relative to the body, such that upon rotation of the cam (6) the follower is lockable into electrical contact with a battery terminal post accommodated by the aperture (4), the slug having a first surface which is complementary to the shape of a terminal post and a second surface which is complementary to the cam (6) to provide an extensive area of contact with both the cam and the post when locked. A battery clamp as claimed in claim 1, wherein the electrically conductive material body (2) is preferably a casting and is of elongate configuration. A battery clamp as claimed in claim 1 or claim 2, wherein the means for releasably securing an electrical cable to the clamp comprises a socket in the body adapted for the insertion and locking therein of a spigot of an electrical connector to which the cable is secured. A battery clamp as claimed in claim 3, wherein the spigot includes a cam formation (21) thereon whereby the connector may be locked into electrical contact with the clamp. A battery clamp as claimed in any of the preceding claims wherein the body includes an insulating cover surround (3) adapted to provide openings therethrough for a terminal post, electrical connections and an adjusting boss (8) of the cam operated locking means (6, 7).

Inventors: RISSIK GEORGE VICTOR, VICKERS WILBRAHAM CHARLES KRUG, RISSIK, GEORGE VICTOR, VICKERS, WILBRAHAM CHARLES KRUGER
Applicants: RISSIK GEORGE VICTOR, VICKERS WILBRAHAM CHARLES KRUG, RISSIK, GEORGE VICTOR, VICKERS, WILBRAHAM CHARLES KRUGER
Application year: 1992
Main classification: H01R11
IPC codes: H01R11, H01R4, H01M2