Improvements in Welding Metals Electrically.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in 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 electric welding, hereinafter fully described
and claimed.
Figure 1 is a perspective of an apparatus which may be used to practice my
invention, and
Figure 2 is a vertical central section through the apparatus for re-enforcing
a weld.
G represents a table, of wood or other insulating material, provided with
clamps M N, having set-screws P O, and connected by the conductors F Q with the
opposite poles of a generator of electricity.
HH represent two articles to be welded together, laid on table G with their
welding edges in contact and secured by the set-screws in the clamps M N.
.
A represents a conductor connected with F and with a binding-screw B on a
conductor K, the end of which may terminate in a roller J, as shown, or may be a
simple flat or rounded end. Resistance-coils A' and F are located in the conductors
for the purpose of directing the bulk of the circuit through either conductor at will,
and more particularly for forming a voltaic arc between the points K and H H, as
more particularly hereinafter described.
E is an insulating-handle on conductor K.
TT represent two insulated rollers on the ends of arms I I, which branch from
the conductor K, and their purpose is to facilitate carrying the lower end on
conductor K along the joint, either in contact with or at a slight distance from H H.
By placing the rollers T T out of line, the lower end of K (the roller J, as shown)
tilting the conductor will throw it in or out of contact with H H.
D represents a hollow conductor (carbon) carried on an insulating-handle E,
connected with the conductor A, and C represents a wire or rod of metal like HH,
passing down through conductor D. This is used when an irregularity, such as is
shown at L, Figure 2, is encountered in the welding edges of H H, the rod C melting
and re-enforcing the joint at L.
My process is carried out as follows :—
HH being placed as shown in Figure 1, the electric current is established through
conductor F, clamp N, articles HH, clamp M and conductor Q, thus heating the
edges of H H. The lower end of conductor K (roller J) is now brought in contact
with the meeting edges of HH, thus shunting a part of the current through
conductors A and K and increasing the local heating effect of the current of the
edges of H H, and conductor K is traversed along said joint. An increased heating
effect may be produced by bringing conductor K into contact with H H, thus
establishing the circuit, then slightly raising conductor K, whereby a voltaic arc is

page_text: formed between K and H H, and traversing the joint with the arc. If an irregularity
like L is encountered, the conductor D is substituted for conductor K, and enough
of wire C to fill the hole L is melted by the voltaic arc. When the edges of HH
are brought to a welding heat, the weld is formed by pressing H H together, and
may be finished by rolling, hammering, or in any other known way.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
-
1. The hereindescribed method of welding metals electrically, consisting in placing
the articles to be welded in contact, connecting them with opposite poles of a
generator of electricity, passing a heating-current through them, simultaneously
traversing the joint with an electric conductor, one end of which is connected with
one pole of the generator and the other end in contact with the joint, and finally
completing the weld by pressure.
2. The hereindescribed method of welding metal electrically, consisting in placing
the articles to be welded in contact, connecting them with opposite poles of a generator
of electricity, passing a heating-current through them, simultaneously traversing the
joint with a voltaic arc sprung between the joint and a conductor connected with one
pole of the generator, and finally completing the weld by pressure.
3. The hereindescribed method of welding metal electrically, consisting in placing
the articles to be welded in contact, connecting them with opposite poles of a generator
of electricity, passing a heating-current through them, simultaneously traversing the
joint with a voltaic arc sprung between the joint and a conductor connected with one
pole of the generator, re-enforcing the joint by supplying like metal carried by the
traversing conductor and fuzed by the arc, and finally completing the weld by
pressure.
Dated this 21st day of May 1890.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.