US2390999A - Joining of wires, particularly fine wires used in the manufacture of electric coils - Google Patents

Description

Dec. 18, 1945. GQGILLIVER 2,390,999

JOINING OF WIRES PARTICULARLY FINE WIRES USED IN THE MANUFACTURE OF ELECTRIC COILS Original Filed March 30, 1943 Attorney Patented Dec. 18, 1945 JOINING F WIRES, PARTICULARLY FINE WIRES USED IN THE MANUFACTURE OF ELECTRIC COILS Gilbert Gilllver, London, England, assignor to I Standard Telephones and Cables limited, London, England, a British company Original application March 30, 1943, Serial No. 481,068. Divided and this application July 25,

'1944, Serial No. 546,520.

October 2, 1942 I 3 Claims.

This invention relates to improvements in the Joining ofwires and is a division of my prior U. 8. application, Serial No. 481,068, filed under In Great Britain date of March 30, 1943, now Patent No. 2,371,438,

dated March 13, 1945. In that specification there was described and claimed the process of joining wires by electric f-use welding and an apparatus for carrying out the process comprising a pair of spaced electrodes, for example of carbon, across which the wires to be joined are bridged, means for clamping the wires against at least one 01' the electrodes and a circuit including an impedance for passing current through the wires. The present invention comprises an improved form 01 apparatus for carrying out such process.

According'to one ieature oi the invention we provide an apparatus for joining wires by electric fuse welding comprising an electrode against which wires to be welded are adapted to abut,

said electrode being mounted to be movable in the direction of length of said wires, means for holding said wires against said electrode and means for connecting one side of an electric supply to said electrode and another side of the supply to said wires at a point away from said electrode andmeans restricting the movemen of said electrodes.

The invention will be better understood from the following description taken in conjunction with the accompanying drawing in which;

Fig. 1 is a perspective view with partsof the casing broken away showing a hand tool for Joining wires according to this invention and Fig. 2 is an enlarged detail view of the wire gripping mechanism incorporated in the tool.

The handle I carries-two contact blocks 2 connected to a suitable electric supply. One or these blocks carries a metal blade 3 extending towards the front 01 the tool and carrying a button 4 extending outside the handle and a contact 5. Under the contact 5 is mounted an insulating block 8 to which is fixed a metal member I carrying a spring blade 8. The member I carries a contact 9 immediately below but not normally touching contact I. The block 8 also carries a wire clamp shown on an enlarged scale in Fig.

2. This wire clamp consists of two fixed members III and I I and a member I2 sliding between them. Coinciding apertures II are formed in the members III and II and an aperture I4, normally out of alignment with aperture ll, in member I 2. A trigger-II pivotally supported in the handle I on shaft Ii has a projection I'I extending through slots II in the fixed members I0 and II and engaging the slidable member I2,

the arrangement being such that when the trigger is actuated it moves membe I2 against a spring I8 to bring apertures Iland I4 into alignment. i

The spring blade 8 carries a carbon electrode opposite the apertures I3. The blade ltends to move away from member I but its movement in this direction is restrained by the head oi! a screw 2| which is screwed into member I and locked by a nut 22, the screw passing freely through an aperture in blade 8. The movement 01' blade 8 towards member I is restricted by a screw stop 23 screwing into member I and held by a nut 24.

The members Ill and I I are connected within the handle to the lower contact block 2.. A

shroud 25 carried by the handle I surrounds members 1,.8. III, II and 12 as shown. The

20 handle I is made in two halves secured together by screws andnuts 26 fitting into recesses in one half.

In operation the wires to be joined indicated at 21 are preferably twisted together and cut oil 25 level. It is. however, not essential to twist the two wires together; they may be placed parallel and close together. The trigger. I5 is then operated to bring aperture It in member I2 into alignment with apertures I3 and the wires 21 to be Joined are inserted through the aligned aperstopped by screw 2|, whereupon the circuit is broken by the wires being out of contact with electrode 20. Trigger I5 is actuated and the wires withdrawn.

The device shown is suitable for the fluxless welding of conductors in electric communication cables, and the like.

It is to be noted that the term wire is not re stricted to circular wire, and may also include a flat thin strip of metal. Thus by the use of the apparatus described the wire 01' a coil winding may be welded to a strip or metal struck up from a terminal of the coil. Also another strip struck up from the same terminal may be welded to an external connecting wire. It is thus possible to produce an electrical equipment without any soldered joints, all joints being made by electrical fuse welding.

It is clear that the apparatus described could be modified to form a bench fitting.

The apparatus described is suitable for welding copper wires or resistance wires or copper wire to resistance wire, but brass, iron or aluminum wires require special treatment.

Joints produced by electric fuse welding have been found to possess a line dendritic structure of the metal throughout the mass into which the 'two wires are fused and this mass is free from voids, whereas in gas welding the fused mass shows a coarse crystalline structure and includes many voids or gas pockets.

What is claimed is:

1. A device for joining wires by electric fuse welding including an electrode against which said wires to be welded are positioned to abut, means for supporting said electrode provided with a resilient mounting for the electrode thereon to be movable in the direction of the length of said wires, means for holding said wires against the pressure of said electrode, said holding'means being positioned in constantly spaced relation to the movable electrode, means for connecting one side of an electric power supply to the electrode and means for connecting the other side oi. said I power supply to said holding means.

2. A device for joining wires by electric fuse welding including an electrode against which said wires to be welded are positioned to abut, termi-' nal means for supporting said electrode to be movable in the direction of the length of said wires, having a resilient mounting for the electrode thereon, means for holding said wires against the pressure of said electrode, means for connecting one side of an electric power supply to the electrode, means for connecting the other side of said power supply to said wires. means restricting the resilient movement of said electrode whereby current passes rrom said electrode to the ends 0! said wires to eflect fuse welding thereof and the restricted movement of the elec trode automatically breaks the (use welding circuit. n

3. A device as claimed in claim 2 wherein the resilient mounting for the electrode consists oi a spring blade secured to a terminal bar and wherein stop means are provided to limit the relative movement of the spring blade relative to the terminal bar.

GILBERT GILLIVER.

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