Improvements relating to the Welding of Metals by Electricity.
Year: 1890

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by Professor ELIHU THOMSON, of Swampscott, Massa-
chusetts; United States of America, Electrician.]
Improvements relating to the Welding of Metals by Electricity.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake, & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My invention relates to welding metals by the agency of electricity, and consists
essentially in the repeated application of a heating electric current and of pressure
alternately to the picces to be welded.
My invention may be carried out by the use of any desired form of apparatus, and
by beating electric currents of the proper volume derived from any desired source.
In carrying my said invention into practice the pieces or objects to be welded
having been placed in the conducting clainps of the apparatus, and in contact with one
another, but without any considerable pressure, a heating electric current of moderatë
volume is passed through them and allowed to flow for a greater or less time according
to the size of the pieces, and according to the number of alternations of current and
pressure which it is desired to employ in completing the operation. The current, is
then entirely cut off or greatly reduced so as to stop the increase of heat in the
pieces, and mechanical pressure is applied to force the pieces more closely together.
This force is then greatly diminished or entirely removed, the heating current is again
applied, and, when the desired beating is secured, is again removed or cut down, and
pressure again applied.
In this manner the heating current and pressure are alternately applied until the
work is finished.
By this means a perfect weld is gradually effected if the operations have been
carefully performed.
In the accompanying drawings,
Figure 1 illustrates an apparatus which may be used in practising my invention.
Figure 2 illustrates another form of appartus which may be employed.
Figures 3 and are diagrammatical representations of the action of the apparatus
shown in Figures 1 and 2.
Referring to Figure 1, the numeral 3 indicates the secondary, 2 the iron core,
and 1, the primary of any transformer adapted to convert alternating electric
currents into currents of lower electro motive force but large volume suitable for
heating the piece or pieces of metal 4, held in suitable clamps forming the terminals
of the secondary. The clamp 12, is provide with suitable means for moving it
parallel to the rods 4, and towards the opposite clamp. The means here shown consists
of a piston which moves in a cylinder 10, and has its rod attached to the movable
clamp 12. 9 is a valve in a water pressure supply pipe leading through the cylinder 10.
8 is a spring which tends to counteract the weight of the parts operating the valve
such as lever 7, and the valve itself. Lever 7, is pivoted at 6, and carries one of two
contacts 5, which, when in connection, close the circuit of the primary 1.
The operation of the apparatus is as follows:-
-
The lever 7, being held upward current flows and the metal 4, begins to soften.
The lever is then depressed to stop the current and open the valve admitting
pressure to the piston so as to force the metals together. The lever is then again
held upward and current allowed to flow while the pressure is discontinued through
the closure of the valve. This is repeated as often as desired, current and pressure
being used alternately, as graphically represented in Figure 3, where C, indicates
current and P, pressure.

page_text: Figure 2 indicates an apparatus wherein the alternating current and pressure may
he applied without entirely cutting off the current during the application of pressure.
15, is a reactive coil which may be placed in the circuit of a primary and is provided
with a movable core 19, the depth of insertion of which in the coil 15, determines
the reactive kick or resistance of the latter, as well understood in the art. Core 19
is operated by means of a lever 7, pivoted at 6, and carrying a pawl 13, which serves
to rotate a wheel 17, step by step. 16, is a pinion carried by wheel 17, and meshing
with a rack 18, by which movement and pressure may be imparted to the work. As
the lever is moved down to move the core 19, and decrease or tend to stop the
current, the pressure is applied by means of the pawl 13. On movement in the
opposite direction which removes the pressure the current is increased and the heating
takes place. This operation is practically the same as in Figure 1, excepting that
the current is gradually kicked back instead of entirely discontinued.
Figure 4, illustrates graphically the manner in which the current and pressure
overlap. In both cases it will be observed there is an alternate application of heating
current and welding pressure, as before described.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent I declare that what I claim is :—
The herein described method of electric welding which consists in the repeated
alternate application of a heating electric current and pressure to the object to be
welded.
Dated this 18th day of Nazzambon 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.