Method of Welding Metals Electrically.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Method of Welding Metals Electrically.
I, CHARLES LEWIS COFFIN of Detroit, County of Wayne, State of Michigan,
United States of America, Chemist do hereby declare the nature of this invention
nd in what manner the same is to be performed, to be particularly described and
scertained in and by the following statement:-
Complete Specification Left, 22nd May, 1890-Accepted, 2nd Aug., 1890
COMPLETE SPECIFICATION.
Method of Welding Metals Electrically.
I, CHARLES LEWIS COFFIN of Detroit, County of Wayne, State of Michigan,
United States of America, Chemist 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 consists in a method of welding metals electrically, hereinafter fully
described and claimed.
The drawings illustrate mechanism by which my invention may be practised.
Figure 1 is a side view of a complete apparatus.
Figure 2 is an end elevation thereof.
Figures 3, 4 and 5 are partial side elevations.
Figure 6 is a section on line a x, Figure 2; and
Figure 7 is a partial end elevation showing an eccentric for operating the clamp
instead of a screw.
My present invention relates more particularly to welding thin metals, which would
be wholly or partially destroyed by the direct action of the heating-current or voltaic
arc; and it consists, generally speaking, in bringing the metal to a welding heat by
enclosing the same between electrically-heated conductors.
A and B represent standards mounted on suitable clamps, one or both of which,
as B, Figure 1, is made movable on its standard in any suitable way, as by the
dovetailed groove and projections a, a, Figure 2.
D represents a lug on the base of the machine, in which is swivelled a screw-shaft C,
provided with a crank E and threaded into standard B, whereby said standard may be
moved to or from the standard A at will.
For the purpose of pressing the articles to be welded together, I have illustrated
the pressure-bar H, having a guide J, sliding in the standard and having a screw-
shaft F slipped through the pressure-bar and engaging with the thread in the hole
tapped in the standard, whereby the bar H may be moved and its upper end pressed
against the articles to be welded.
Secured to the top of each standard A and B, but insulated therefrom by the
insulating material I, is a clamp. The mechanical construction of this clamp is not of
much importance, and that which I have illustrated is as follows:-―
V represents a U-shaped plate, one end of which is secured to the top of the
standard, the other end rising above and passing over the standard, as clearly shown
in Figures 2 and 7, and the lower end of V forms the lower clamp.
N represents the upper plate of the clamp, having at its end an upper extension O,
on which is formed a projecting dovetail n, Figure 6, taking into a similar groove in
the upright part of V.
N and V are insulated from each other throughout, as though there is no electrical
connection between them, when, as indicated in the drawings, the two parts of the
clamp are connected with the poles of a generator; but the same result may be
obtained by insulating the two parts of the clamp from the things contained between
them, when it is immaterial whether N and V are insulated from each other.
Q represents a screw-shaft provided with any suitable means for rotating the same,

page_text: tapped through the upper part of the plate V and swivelled into plate N, by means of
which the plate N may be raised or lowered.
K and L represent two articles to be welded together.
PP represent plates of conducting material, (preferably carbon) between a pair of
which in each clamp the articles K and L to be welded are held, the said plates P in
Figure 1 having no insulation between themselves and the articles K and L, but in
Figures 3, 4 and 5, being insulated therefrom by the strips of insulating material I'³,
placed between the plates P and the articles K and L.
S and T represent electrical conductors by which the upper plates N of the two
clamps are connected with the opposite poles of a generator of electricity..
When the plates N and V are insulated from each other and the plates P are
insulated from the articles K and L to be welded, I connect the plates N and V of
one clamp with one pole of a generator by the conductors T and T', and the plate N
and V of the other clamp with the other pole of a generator by conductors S S', as
shown in Figures 3, 4 and 5; or T and S may be one circuit and T S¹ another
circuit.
In the arrangement shown in Figures 1 and 3, the opposite plates P of the two
clamps are not in contact, and the articles K and L to be welded do not reach the
ends of the plates P.
The operation of this arrangement is as follows:-
The ends of the plate P are brought into contact and slightly separated, whereby a
voltaic arc is formed between the opposite upper plates P and also between the
opposite lower plates P, thus heating the ends of said plates, and thereby beating by
contact the interposed articles K and L to be welded. When articles K and L have
reached a welding heat, they are pressed together to form the weld by rotating the
screw-shaft F, which causes the bars H to press K and L together. The shaft E may
be moved to draw A and B apart to give space for the working of joint at K and L
when they are pressed together.
The bars H are provided at their upper ends with insulating material i. In the
arrangement shown in Figure 4, the opposite upper plates P and the opposite lower
plates P are in contact, and the articles K and L are in contact.
In this arrangement, the plates P are heated by passing heating-currents through
them, and they heat the articles K and L by contact, and when K and I are
sufficiently heated, they are pressed together, as before.
The arrangement in Figure 5 is the same as that of Figure 4, except that K and L
are not in contact and are pressed into contact when sufficiently heated through the
heating of the upper and lower plates P by the passage of a heating-current.
The insulation I may be of a refractory material which will not be destroyed at the
temperature necessary to bring K and L to a welding-heat. When the weld is cold,
or while cooling, it may be finished by rolling, hammering, or in any other desired
way.
In the arrangement shown in Figure 7, 1 substitute an eccentric b, pivoted to the
upper end of the plate V by a pin c and connecting with the plate N by a strap and
connecting-rod Q1, this being a mechanical equivalent for the screw-shaft Q for this
purpose.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described method of welding metals electrically, consisting in
enclosing the articles to be welded between conductors electrically heating the.
inclosing-conductors, and forming the weld by pressing together the articles to be
welded when brought to a welding heat.
Dated this 1st do. of M1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.