Improvements in Apparatus for Heating or Welding Metals Electrically.
Year: 1894

page_text: COME LEIE DI PUIFICATION.
Improvements in Apparatus for Heating or Welding Metals
Electrically.
A communication by CHARLES Lewis CoFFIN, of 980, Jefferson Avenue, 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 :-
This invention consists in an improved apparatus for heating or welding metals
electrically, hereinafter fully described and claimed.
Figure 1 is an end elevation, partly in section, of an apparatus which may be
used to practise the invention, and
A, represents legs or supports, each of which carries a clamp K made of such
form as to receive the work to be operated upon, which in the illustration is shown
as a tube or ring, and provided with set screws by which the work may be fastened
in the clamp. W represents the material to be heated or welded, shown as a tube
or ring which is to be welded together with a lap joint. C represents an extraneous
conductor or carbon held in an insulating handle H and connected by conductor X
with one terminal of a source of electricity G, the other terminal of which is
connected by a conductor Y with the material W, the connection shown in Figure 1
being through one of the clamps K, or it may be made with the material direct.
R represents a variable resistance interposed in conductor X, by means of which
the current can be regulated. k represents a cross bar supported at its ends on the
two clamps K K, and S represents a screw shaft threaded through bar k and
swivelled at its upper end into a plate t. TT represent standards secured to, but
insulated from plate t, to the upper ends of which are pivoted two carbon holders j
carrying carbons c c². M represents a magnet carried on a support b secured to
arms T T, and the core of magnet M is threaded as shown at S¹ and provided with
a thumb piece, whereby said core may be adjusted with relation to the meeting
point of the carbons c c as shown in Figure 1. Carbons cc' are connected by
conductors x and y with the terminals of a generator G, a variable resistance Ri
being inserted in one of said conductors, and the terminals of the electro magnet M
are connected by shunt circuits Z Z with said conductors y and x, a variable
resistance R' being introduced into said circuits.
The carbon C and the carbons c c¹ are shown in circuits connected with the
separate generators, but it is evident that they may be all connected with the
terminals of one generator.
Referring to Figure 1, a current being passed through conductors X and Y,
carbon C and material W, by bringing carbon C in contact with the material and
then slightly raising it, a voltaic arc is formed between said carbon and the
material. A current being passed through conductors x and y and carbons c c¹
(said carbon being in contact) by separating said carbons a voltaic arc is formed
between them in proximity to the underside of the material W, and this are may
be thrown towards said material by magnet M, as described in my correspondent's
previous Patent application No. 494 of January 9th 1894. The result is that the
outer side of the upper lap and the inner side of the under lap are simultaneously

page_text: heated by independent voltaic arcs, and both are rapidly brought to a welding heat,
and may be welded in any desired manner, while, if it be attempted to make a lap
joint on metal of any appreciable thickness, say one-quarter of an inch, by means
of one arc applied either to the outer or inner lap, said lap will be melted before
the other lap approaches a welding heat.
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 clairn is―
1. In an apparatus for electrically heating metal, the combination of means for
connecting the metal to one terminal of a source of electric energy, an extraneous
conductor connected to the other terminal of said source of electric energy, two
extraneous conductors and means for maintaining an electric arc between said
electrodes within the field of force of a magnet.
2. In an apparatus for heating metal for making a lap joint consisting of a clamp
for holding the material with the lap in position, mechanism for maintaining a
voltaic arc on the outer side of the outer lap and mechanism for simultaneously
maintaining a voltaic arc on the inner side of the inner lap within the field of force
of a magnet substantially as shown and described.
Dated this 8th day of January 1894.
WM. P. THOMPSON & Co.,
Agents for the Applicant.