Improvements in or relating to Welding Metals Electrically.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to Welding Metals Electrically.
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,
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 inven-
tion and in what manner the same to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention consists in an improved mode of welding metals electrically.
The drawings are diagrammatic views,
Figures 1 and 3 showing that mode in which the article to be welded is in
circuit with an extraneous conductor, and au arc is formed between said article and
said conductor, and
Figure 2 showing an are sprung between two conductors extraneous to the
material to be welded.
In all the drawings, C represents a source of electric energy, X and Y conductors
leading therefrom, O O carbons, H insulating handles for said carbons, t the line
of proposed joint or seam to be welded, and d the articles to be welded together.
RR in Figure 3 represent resistances and ', y y¹ represent conductors for
placing the two carbons OO and the material B in multiple arc.
In the operation of welding shown in Figures 1 and 3, where an arc is sprung
between the material and an extraneous conductor, the effect of such arc is to
modify the character of the metal, usually to convert iron into steel, and thus
destroy the homogeneity at the joint.
For the system illustrated in Figure 2, this evil does not occur if the carbons OO
are held at such a distance from the metal that the carbon particles forming the
voltaic arc do not affect the metal, but if the carbons are held too near the metal,
the same result, though to a smaller extent, may occur. For the purpose of
avoiding this difficulty, the arc is applied not on the line of the proposed weld t
but at such a distance therefrom (indicated by the dotted lines S) that the heating
effect thereof will extend to the line of weld t, whereby the modifying or
'steclifying" effect of the arc is confined to the line of its application and the
character of the metal at the proposed line of weid is unchanged. When the metal
at the line of the proposed seam is brought to a welding heat in this manner, the
weld may be completed by pressure, or hammering or in any known way.
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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 mode of heating metal electrically for welding, consisting
in subjecting said metal to the action of a voltaic are at a short distance from the
proposed seam, whereby the metal is not changed by the action of the arc at the
line of weld.
Dated this 27th day of February 1893.
WM. P. THOMPSON & Co.,
Agents for the Applicant.