US650861A - Electrical connector and method of making same. - Google Patents

Description

No. 650,86I.

, Patentedlune 5, |900. T. J. MGTIGHE.

ELECTRICAL CONNECTOR AND METHOD 0F MAKING-SAIE.

(Appumion med mar. ao, 1900.)

(lo Modal.)

MM, W /w m m .w Md Mw UNITED. STATES PATENT OFFICE- THOMAS J. Marlena, or NEW YORK, N. Y.

ELECTRICAL coNNec-ron AND METHOD oF'MAK'mc SAME.

SPECIFICATION formingV part of Letters Patent No. 650,861, dated J une 5, 1900'. Application filed Harel: 30, 1900. Serial No. 10,838. (No modcl,

This invention relates to the manufacture of electric-railway-rail bonds, especially of that class wherein the terminals or rail-attaching studs are fixed on the extremities of a flexihle'connector consisting of a number of separate wiresor bars or a piece of ordinary wire cable, such terminals and connector being usually of copper.v As it is desirable that there should be no appreciable resistance between the connector and its terminals, various plans have been adopted to secure a close contact. A'Ihe ends have .been placed in a mold and molten copper poured in to fill around the connector and formthe stud, and while both terminal and connector are at a high temperature a drop-hammer is applied to consolidate the parts together.' plan is to form the terminals first, by casting or otherwise, then insert lthe cable or connector, bring both up to a welding temperature,

and thenpress them into a substantiallywelded condition. In all methods involving the application of heat the high temperature causes the rapid formation of oXid on the connector itself, thus appreciably reducing its.

conductivity, and it practically prohibits the use of insulation on the connector.

In practicing my invention I do not raise the temperature of, the cable or connector, bnteiect the union of the parts cold, thus avoiding oxidation and obtaining a number of advantages.

To this and other ends my invention consists in the manufacture of electric connecting devices-such as railway-rail bonds, dynamo-terminals, &c.-by swagug the parts together by great pressure applied cold, substantially as hereinafter fully described and claimed.

In the drawings which form part of this Another,

specification, Figure 1 is a sectional view civ Fig. v5 shows a plan and edge view of the' same with the cable inserted.V and `the two coldswaged together. Fig. 6 shows an edge and plan view of a bus-bar coupling or clamp and iiexible'connector cold-swaged together.

For making rail-bonds I use a shaping-die A, a confining-die B, and a plunger C. The precise shape of the working parts of thesev will depend upon the shape to be given the terminal. I show one end of a rail-bond composed of the rail-attaching stud d, its head e, and the flexible cable f.

The confining-die B may have a cavity g cut in it, as shown, for forming part of the head e, or the shoulder-cavity h may be recessed deeply enough in the die Ato avoid making any cavity in the die B. The die A has a hole '1T bored through it, the lower 'por-A tion being tapered to facilitate withdrawal of the pressed terminal. The plunger C is arranged to enter the hole t' and, if desired, may be attached to the platen of the press.

I take a cast or drop-forged copper terminal approximating the desired finished form, as shown in Fig. l, having a holeV or socket formed in it transversely to receive the end of the terminal f. This hole may be round; but I prefer a flattened or elliptical form, as shown.v 'I prefer to clean the terminal with acid or otherwise and remove all oxid or scale and dirt from the surface, leaving the latter bright and untarnished. The end of the cable f is then inserted in the hole, as shown in Fig. 1, and the dies are brought together,

after which great pressure is applied by meansl of the plunger C, actuated by a suitable press. This presses upon the end of the stud d. As the pressure increases the metal of the terminal is compelled to low and fill all the cavities in the mold or die, consoli-4 dating the whole mass of the wires of cable f in IOO and with the head e and the stud d. By this method of swaging cold and under great pressure I produce a close union of the wires of the cable with the terminal d e, an effect which I call cold Welding. Thel effect of the great pressure is illustrated in Fig. 3, Where it is seen that the metal of the terminal fills the external crevices of the cable, the

voids in the cable have been eliminated, and the originally-round Wires are pressed into hexagonal shape, bringing all the surfaces into such intimate and' cohesive contact as to constitute a weld for the purposes intended and without the possibility of oxidationvor burning by overheating.

lVhile the invention is thus designed and shown as especially applicable to the manufacture of rail-bonds, various other electrical applications come within its scope. alnple, Figs. 4 and 5 illustrate it as applied to dynamo-terminals. For large generators the connections between the movable brushholders ,andthe stationary counectiomboard of the machine are usually made of very flexible cable, and the cable is covered with insulation. The terminals are usually attached by soldering, with resulting im perfect and uncertain conductivity and damage to the insulation by heat. I make such a terminal T of soft copper, with the socket s', into which the end of the cable f is inserted, and then by using appropriate dies and great pressure I swage the whole mass into the abovedescribed condition of a cold weld, as in Fig. 5, aord'i'ng perfect conductivity without injury to thelinsulation on the remainder of the cable.

In Fig. 6 I shoiv the same method applied to the socketm of a clamp n for attaching a branch cable f"-to the bus-bar P of a switchboard. In practice I find that a pressure of about one hundred thousand pounds per square inch is well adapted to effect the desired result.

As compared with the usual soldered connection my cold-Welded terminals have the important advantage that under an overload of electric current there is no solder to melt and run out and make trouble.

Having described my invention, I claim as nev'v and desire to secu re by Letters Patentl. The method of uniting an electrical conductor toa metallic terminal, which consists in inserting one into the otherand cold-welding them together by pressure.

2. The method of uniting an electrical conductor to a metallic terminal, consisting in inserting one into the other and cold-swagin g them into mutually-coherent homogeneous masses.

3. The method of uniting an electrical conductor to a metallic terminal, consisting in inserting the conductor into the terminal and swaging the two together under pressure sufficient to cold-weld the contacting surfaces.

4. The method' of manufacturing railbonds, consisting in fitting the ends of a flexible conductor into suitably-shaped terminals and swaging the parts together under pressure sufficient to cold-Weld the contacting surfaces.

5.v An electrical connection composed of asuitably-shaped terminal and a flexible conductor swaged and cold-welded together.

6. A rail-bond consisting of a flexible conductor and terminals having shoulders and attaching-studs, said terminals and conductor being swaged and cold-welded together.

In testimonywhereof I aix my signature in presence of two witnesses.

' THOMAS J. MCTIGIIE.

Witnesses:

Trios. A. CoNNoLLY, Jos. B. CoNNoLLY.

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