US2215416A - Battery terminal - Google Patents

Description

. 17, 1940. 1...c. woLcoTT BATTERY TERMINAL Original Filed Aug. 26,1937

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z 4 wk w m 7 4 4 Patented Sept. 17, 1940 UNITED STATES BATTERY TERMINAL Leslie 0. Wolcott, Warren, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Original application August 26, 1937, Serial No.

Divided and this application May 17, 1940, Serial No. 335,815

6 Claims. (01. 173-259) This invention relates to terminal members for storage battery connectors, and has particular reference to battery terminal clamps cast of soft metal, such as lead, or an alloy of lead and other elements, and which clamps are to be attached to a terminal post by clamp means incorporating a screw device.

This application is a division of Serial No. 160,948 filed August 26, 1937, for Battery terminals.

In a battery terminal clamp of the type indicated, there is a tendency for the clamp portions of the terminal to be thrown out of alignment or parallelism, when clamping force is exerted on the arms, that results in the flow or squeezing of the soft metal into engagement with the threads of the screw device. In the usual form of clamp, when the screw device is operated, the clamp arms are drawn out of parallelism so that the opposed surfaces of the arms, or their free ends, tend to converge at a point outside of the clamp, which causes the bores through the clamp arms to be thrown out of alignment and bind on the shank or threaded portion of the screw device. In some instances this binding is sumcient to cause bending of the screw device, especially where the clamp member is formed of relative hard metal. In some instances the extreme clamping of the arms causes fracture and even breakage of the ring portion of the member thus requiring early replacement of the terminal clamp. It has been found that many of these faults may be obviated, if the arms of the clamp can be maintained in substantial parallelism throughout the'clamping operation.

It is therefore an object of the instant invention to provide a battery terminal clamp that will be relatively free from fracture while it is being clamped in place upon a battery post.

It is another object of this invention to provide a battery terminal clamp that will be relatively free from binding effect between the clamp arms and the clamping device.

A further object of this invention is to provide a battery terminal clamp that will make effective contact with the terminal post of the battery, without any attendant deformation of the parts, and that will be readily releasable from the battery terminal post upon loosening of the clamping device.

Another object of this invention is to provide means in a battery terminal member for preventing injury to the clamp arms when the terminal is fixed in place.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention-is clearly shown.

In the drawing:

Fig. 1 is a fragmentary plan view of a battery showing a terminal clamp, incorporating the instant invention, attached thereto.

Fig. 2 is a horizontal sectional view on an enlarged scale through the terminal clamp, removed from the battery post and without the clamping device.

Fig. 3 is a fragmentary plan view of the terminal member applied to a battery post, and illustrating a modification of the terminal mem ber.

With particular reference to the drawing, 1 0 indicates a battery providing a terminal post I 2 and a cell cap it, all of which is structure well known I to those experienced in the art. For conducting the current stored in'the battery to selected' d evices, a battery lead or connector l6 is provided that is coupled to the battery post l2 in good conductive relation, by means of a terminal clamp member l8, that includes a screw or clamp device 20 for attaching the clamp member to the battery post.

In order to accomplish the several objects hereinbefore proposed, the battery clamp member [8 is carefully designed to incorporate the stated features. The terminal clamp member l8 herein disclosed, comprises a casting of soft metal, such as an alloy of lead and antimony, and at the time of formation is cast about the bared end 22 of the battery lead l6, and so as to enclose a reinforcing strip 24, as well as the end portion of the insulation of the conductor l6.

It is preferred that the stock from which the strip 24 is fashioned shall be devoid of any appreciable springback function, for which reason a quality of metal known as dead soft steel is used. As to configuration, the reinforcing member 24 comprises an elongated strap bearing large apertures 28 at each end 29, while points intermediate the apertures 28 are struck up from the plane of the strap to form pimples 34, substantially as indicated. When the strip has thus been provided, it is bent into U-form substantially as indicated so that the leg portions 36 terminate with the apertures 28 in substantial alignment. This positions the pimples 34 on the outer surface of the leg, and disposes them in substantially diametrical relation as respects the locus of the bend.

With the reinforcing strip so fashioned, and N having been dipped or lead coated, it is placed in the mold cavity in proper adjusted relation with respect to the battery lead It, whereupon the cooperating cavity members are closed and the molten lead 'or casting metal introduced into the cavity under pressure. The reinforcing member 24 being so positioned-is thereby properly centered with respect to the mold cavity such that the molten metal substantially completely surrounds each and every part of the reinforcing member.

As a result there is provided a battery terminal member having a shank 40 that ends in a collar 42, bonded to the conductive element of the battery lead, and embracing an end portion of the insulation, as indicated at 44. Joined to the shank portion there is a split ring or clamp portion 48, ending in the clamp arms 48 and 49, that embraces the reinforcing member 24, and provides an outer layer of cast metal 50 covering the outside surface of the reinforcing member, and

.an inside layer 52 covering the inside surface of the reinforcing member 24, the layers 50 and 52 being joined together at the edge of the reinforcing member.

The central portion of the clamp member provides a circular opening 58 for reception of the battery terminal member, substantially as indicated in Fig. 1, and a lateral slit 60 opens from the aperture 58 outward between the clamp arms 48 and 49, substantially as illustrated. The drawpin part of the mold elements is sumciently smaller than the diameter of the apertures 28, to permit a coating of lead to form a lining for the apertures in the form of a sleeve substantially as indicated in Fig. 2 yet the draw pin is of sumcient cross sectional dimension to allow for easy passage of the clamp device 20, such as the shank of the bolt 64, that is received in the aligned apertures 66 in each of the clamp arms 48 and 49. The casting is otherwise fashioned to provide an abutment 88 to be engaged by one flat side of the head 10 of the clamp bolt 64, and keeps the bolt from turning when the nut of the screw device is run-down to secure the clamp arms about the battery post l2.

In order to prevent deformation of the clamp arms, and so as to insure that the clamping force will be more evenly distributed, an abutment or compression lug I2 is formed integral with one of the clamp arms and is so fashioned that it extends across the slit 60, and is adapted to engage the opposite clamp arm, after a certain amount of clamping force has been exerted.

As an obvious alternative, a pair of opposing compression lugs, such as illustrated at 12a and 12b in Fig. 3 may be provided, one on each clamp arm, so that clamping of the arms will result in engagement of the lugs prior to collapse of the terminal member, as hereinabove set out. There- .fore, reference herein to the compression lug,

contemplates inclusion of constructions where means are provided between the clamp arms, that operate to prevent the undesirable deformation of the clamp or terminal member.

With a battery terminal clamp so fashioned it may be readily and securely fixed to a battery terminal post as indicated in Fig. 1, or 3 without the usual danger of deformation or rupture. With the battery clamp in place, and a hard metal washer 14 disposed on the bolt 64 and positioned between the nut and the clamp arm, secure and efllcient electrical connection may be made with certainty. Running the nut down upon the bolt .moves the nut against the hard metal washer which eliminates carving away of the clamp arm due to the movement of the nut. The clamping force of the screw device draws the clamp arms together until the abutment 12 engages the opposite clamp arm, or the lug 12a engages 12b,

and the reinforcing member 24 distributes'the movement of the clamp arms throughout the ring portion of the clamp member, instead 'of allowing the clamp arms to bend at the juncture of the arms and the ring, as has heretofore been the case. As a result, a more firm engagement is attained between the clamp element and the battery terminal post, and the attendant is informed by the marked increase resistance in turning of the screw device, that a complete electrical connection has been made.

Operation of the screw device to clamp the arms upon a battery post will cause the lug 12, or lugs 12a and 1212, at the extreme ends of the clamp arms to prevent cocking the arms out of parallelism, and/or bending of the clamp arms at their juncture with the clamp ring, and/or bending of the clamp bolt, and/or entry of the soft metal into the threads of the clamp bolt by reason of which binding of the clamp bolt in the apertures in the clamp will result. Thereby, the clamping force effected by the screw device will cause the ring portion of the clamp member to firmly compress about the entire surface of the battery post I2, and will effect good electrical connection, devoid of any breaking or rupture of any part of the battery terminal. Upon release of the clamping device, the bolt 44 may be easily removed and the terminal member removed from the post l2 without dimculty.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In a molded battery terminal cast of soft lead, a split ring providing a pair of parallelly extending laterally arranged apertured clamp arms, said arms being normally spaced apart and providing interposed means integrally Joined to the end .of one of the arms and adapted to project across the space, and a clamp screw passing through the arms inwardly of the interposed means for clamping the terminal member on a battery .post, said interposed means adapted to engage for preventing substantial deformation of the arms when clamped.

2. In a molded storage battery terminal clamp, a lead attaching portion having a pair of spaced parallelly extending clamp arms, said arms being apertured in alignment for reception of a clamp screw, a projection molded integral with and at the extreme end of one of the arms so as to extend toward the other arm for engagement therewith when the arms are drawn toward each other, said projection being spaced outwardly from the apertures for the clamp screw and maintaining the apertures in the arms in substantial alignment during clamping, so that the threads in the clamp screw will pass through the apertures without binding.

3. A battery terminal member of the clamp type, comprising in combination, a casting of soft lead alloy providing an open ring with a pair of laterally extending arms, said arms being provided with aligned apertures, a screw device comprising a nut with a cooperating bolt disposed in the apertures for drawing the arms together, means for preventing substantial deformation of the arms when the screw device is tightened, and means substantially preventing binding efiect between the clamp arms and screw device, said last named means comprising an integrally formed lug located at the end of one of the arms and extending toward the opposite arm, said lug preventing the extreme ends of the clamp arms ad vancing toward one another more rapidly than the portion joining the clamp ring.

4. In a battery terminal clamp cast of soft metal and having a pair of spaced arms for reception of a clamp screw, the combination comprising, means remote from the clamp screw for preventing substantial collapse of the arms when the screw device is tightened, and means for maintaining substantial alignment of the apertures for receiving the screw device, both of said means comprising a 'member interposed between the arms at the extreme ends thereof and projecting across the space to abut an arm and obstruct the approach of the arms when the clamping device is operated to tighten the terminal member upon a battery post.

5. A molded soft metal battery clamp comprising a split body adapted to be clamped around a battery terminal and being capable of deformation when tightly clamped, opposed lugs formed integral with and extending outwardly from said body on opposite sides of the split thereof and being likewise deformable when tightly clamped, said lugs having bolt receiving openings therein and an abutment portion formed integral with one of said lugs at the free end of the latter and extending towards the other lug for engagement therewith to control the deformation of said lugs and body upon the clamping thereof to the battery terminal.

6. In a battery terminal clamp cast oi. soft metal and having a pair of spaced arms for reception of a clamp screw, the combination comprising, means remote from the clamp screw for preventing substantial collapse of the arms when the screw device is tightened, and means for maintaining substantial alignment of the apertures for receiving the screw device, both of said means comprising a member integrally joined to an end of one of the arms in interposed relation between the arms so as to be spaced outwardly from the clamp screw, and project across the space to abut the end of the other arm thereby preventing the approach of the arms when the clamp screw is operated to tighten the terminal member upon a battery post.

Y LESLIE C. WOLCOTI.

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