Improvements in or appertaining to Electric Welding.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in or appertaining to Electric Welding.
A communication from abroad by CHARLES LEWIS COFFIN, of Detroit, in the County
of Wayne and State of Michigan, United States of America, Chemist.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E. of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, and 323, High Holborn, in the County of Middlesex, Civil
Engineer, 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 :-
The invention relates to improvements in electric welding, hereinafter fully described
and claimed.
In one arrangement a voltaic arc is formed in such manner that it shall extend
outside of a straight line joining the ends of a positive and negative conductor, and
then drawing the conductors while the current is passing along the joints to be
welded, whereby the joint is submitted to the action of the voltaic arc; and, as an
addition to this process, the invention further consists in feeding to the joints to be
welded and within the influence of the voltaic are a strip of metal, which is fused
by the arc and deposited on or in the joint, whereby the welded joint is re-
enforced.
The apparatus by which this may be carried out may be varied in form or construc-
tion, it only being necessary that the arc when formed shall spring beyond the ends
of the carbons, which may be done either by the position of the carbons or by
deflecting the arc magnetically in a well known manner.
A mechanism which may be used to practise this part of the invention is illustrated
in Figures 1 and 2 of the accompanying drawings, which are front clevations,
being exactly alike except that Figure 2 has added a guide for feeding the re-
enforcing piece of metal.
B represents a carbon holder, and A represents a box on said holder, containing
mechanism for feeding the carbons as they are worn away, which is not shown, as
it forms no part of the invention designed to be hereby secured.
CC represent two carbon pencils secured in holder B at an angle with each
other, whereby the voltaic arc L is sprung outward from the straight line joining
the point of the carbons, as shown in the figures, so that this are may be brought
into contact with the joint to be welded without touching the joint with the
carbon.
F represents an insulated handle for the carbon-holder B, by which it may be
operated by an attendant.
GH represent binding-posts through which the poles of the generator may be
connected with carbons & C.
EE represent insulated rollers, which may be used to support the holder B and
permit it to be drawn along the joints, the rollers S resting either on the sheets of
metal to be welded or on table carrying the work. These may be used or not, as
willed.
In Figure 2, I represents a guide, consisting of a hollow pipe secured to the
carbon-holder B, and D represents a wire or strip of metal, which passes through the
carbon-holder and through said guide I, so that its end passes between the points
of the carbons CC without touching either of them. The wire D should preferably
be insulated from the carbon-holder B, so that it cannot possibly short-circuit the
carbons. It is evident that when the points of the carbon are placed over the joints
to be welded, the end of the wire D will lie upon the joint, and that it will be
fused by the voltaic arc at the same time the joint is fused, whereby the fused

page_text: portion of the wire D will be laid along the joint, thereby re-enforcing the
welding.
Mr. Coffin is aware that prior patents have described the process of electric welding
in which the voltaic are his heen sprung between the metal to be welded as one
pole and a movable conductor as the other pole, and does not claim any such process
herein.
Figure 3 shows another arrangement, in which :—
A and A reprosent the articles to be welded, and GC represent two carbons
or other conductors, between which the voltaic are which does the welding is
sprung.
B B represent two conductors, which are in electrical contact with the articles A A',
respectively, and the current from the generator of electricity is applied as
follows:-
From one pole of the generator the current flows through the wire W and
conductor B into the article A, thence into the article A', traversing the joint to be
welled, and out through the conductor 13'. Thence it passes through the carbon or
conductor (, forms the voltaic are at the lower end of this conductor, passes forward
through the other carbon or conductor C, and thence off to the other polo of the
generator through the wire W.
If desired, two generators may be connected, one with the conductors B B' and the
other with the carbons CC, the essence of the invention consisting in simultaneously
traversing the joint to be welded by an electric current and subjecting it to the
action of a voltaic arc.
Of course the articles A and A' must be insulated in practising this process.
The arrows indicate the course of the current or currents.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declaro that what I claim is :-
1. The herein described method of electric welding, consisting in forming a voltaic
are between two conductors extending outward from said conductors and submitting
the joint to be welded to the action of said are.
2. The herein described method of electric welding, consisting in forming a
voltaic are between two conductors extending beyond the points thereof, feeding a
strip of metal into the are between the conductors, and submitting the joints to be
welded and said strip of metal simultaneously to the action of said are.
3. The method herein described of welding two articles together, which consists
in placing the two articles against each other and welding the joint by simultaneously
traversing such joint by an electric current and subjecting it to the action of a
voltaic arc, substantially as set forth.
4. The herein described apparatus for welding metals electrically substantially as
set forth.
Dated this 20th day af August 1890