Improvements in or relating to Electrically Welding or Heating Metals.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to Electrically Welding or Heating
Metals.
A communication by CHARLES L. 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, Man-
chester, 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 ivention consists of an improved method of electrically welding or heating
metals, hereinafter fully described and claimed.
In the accompanying drawings;
Figure 1 is a perspective view;
Figure 2 an elevation on line a, Figure 1, showing the method applied to that
system of electric welding in which an arc is sprung between the material in circuit
and an extraneous conductor ;
Figure 3 a top plan view; and
Figure 4 a section similar to Figure 2, showing the invention applied to that
method of welding in which the material is subjected to the action of an arc sprung
between two extraneous conductors.
In all the figures, M represents material to be heated or welded, S represents
the line of seam or weld, along which the metal is to be heated, and the figures
represent extraneous conductors, usually carbons.
Referring to Figures 1 and 2; M represents two plates of metal, between which
a scarf joiut is to be made. The material M is connected with one pole, or similar
poles of a number of generators of electricity, as for instance the terminal or
terminals of the secondary of a transformer, and each of the conductors 1, 2, 3, 4,
and 5, and 11, 2, 31, 4¹, etcetera, are connected with the other pole or poles. The
conductor 1, 2, 3, 4 and 5, are placed above the material M, and on being brought
into contact with said material and then slightly separated therefrom, the arcs are
formed between said conductors and the material, by which the material is brought
to a welding heat. The conductors 1, 2, 3, 4', etcetera, are placed under
material M, brought in contact therewith, separated therefrom, by which means
voltaic arcs are formed between said conductors and the material to heat the material
from the under side.
My correspondent has found by experience that, while it is very desirable in
many cases
to thus heat the metal simultaneouly from both sides, if the
conductors 1 and 11 be placed opposite each other, the tendency is to draw one of
the arcs as from conductor 1, toward the metal, and repel the arc from conductor 1¹
away from the metal, and the close proximity and opposition of the arcs render
regulation difficult by reason of magnetic or amperian or current effects, this
tendency being strongest when the metal M is a magnetic metal such as iron. He
finds it necessary in order to avoid this to alternate the upper and lower
conductors 1, 11, 2, 21, etcetera, shown in the drawings, in which case this tendency
does not exist, or is greatly modified or lessened, and both the upper and lower arcs
act regularly on the metal. In Figures 1 and 3, the material M is subjected along
the seam to the action of arcs formed above the metal by pairs of extraneous
conductors 1, 1, 2, 2, 3, 3, 4, 4, and 5, 5, connected to suitable source or sources of
electric energy, and to arcs formed below the material by pairs of extraneous

page_text: conductors 11, 11, 21, 21, 31, 31, 41, 4, etcetera, connected to suitable source or sources
of electric energy, and those are arranged in the same manner as above described,
the arc formed by conductors 11, 11, below the material being between the arcs
formed by conductors 1, 1 and 2, 2, above the material. When the metal is
sufficiently heated it may be welded or worked in any desired manner.
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 heating metal consisting in subjecting the
opposite sides of the metal simultaneously to the action of voltaic arcs alternated in
position.
Dated this 26th day of Santamba- 1000
WM. P. THOMPSON & Co.,
Agents for the Applicant.