Improvements in Welding Metals Electrically and Apparatus therefor.
Year: 1890

page_text: Date of Application, 8th May, 1890-Accepted, 28th June, 1890
COMPLETE SPECIFICATION,
Improvements in Welding Metals Electrically and Apparatus
therefor.
A communication from abroad by Charles L. Coffin, of Detroit, in the County of
Wayne, and State of Michigan, United States of America.
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 328, 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 an improved process of electric welding, hereinafter fully
doscribed and claimed. The invention differs from the known process of electric
welding in which the two articles to be welded are brought into contact and heated
by the effect of an electric current passing through them, in that it utilises the
enormous heat of the voltaic arc, and therefore permits much larger masses to be
welded, and it is operative with much less current.
Figure 1 of the drawings is a perspective view of one form of apparatus which
may be used to practice the invention.
Figure 2 shows a slight modification, in which the onds of the rods to be welded
are bridged by a light piece of metal which serves to complete the circuit and is
destroyed by the passage of the current, thus forming the voltaic arc.
Figure 3 is a sectional olevation of the apparatus so constructed that the welding
operation can be performed in a non-oxidising medium.
Referring to Figure 1 :-
A, represents a base, to one end of which is secured, but insulated therefrom, a
block B, provided with a cap H and bolts P to form a clamp. C represents a similar
block to, but insulated from, the other end of the frame, and extended, as shown at C',
to form a bed for a movable clamp D, having a cap G secured thereto by the bolts O.
K represents a screw-rod passing through clamp C, and having a collar on its inner
end (not shown) and tapped through clamp D, and terminating in a crank J at its
outer end.
I, represents a box to steady screw-rod K, secured to bed C'.
WW represent two metal rods to be welded together, clamped in the clamps
BH and DG in line with each other.
Y and L indicate electric conductors leading from the poles of an electrical genera-
tor, and respectively connected to the resistanco-switch E and cut-out switch F.
E represents a resistance-switch for the purpose of regulating the current, and F
represents a switch by which the circuit may be opened or closed.
M and N represent electrical conductors connecting the switches with the blocks
C and B respectively.
These switches and electrical connections are well known and form no part of the
invention.
The operation of the invention is as follows :-
The electric current being turned into the piece W W, the clamp D G is moved
by turning the screw-rod K until the ends of the rods W W come in contact, closing
the current. The screw-rod is then reversed, slightly separating the ends of the rods
and causing a voltaic arc to be formed between them, by which the ends of the rods
are rapidly brought to welding heat. When this has been attained by means of the
screw-rod K, the ends of the rods W W are pressed firmly together and held in
contact until the weld is completed; or, instead of bringing the ends of the rods W W
together and then separating them to form the arc, the space between them may be

page_text: bridged by a light piece of metal S, Figure 2, which serves to complete the circuit,
and is destroyed by the passage of the current, thus forming the voltaic are.
Figure 8 shows the apparatus so constructed that the welding operation can be
performed in a non-oxidising medium.
In this Figure:-
A, represents a box supported on legs B and having a tight-fitting cover a, which
may be bolted thereto. (represents a stuffing-box, through which slides a tight
box E, carrying on its end a clamp F, insulated from the box E to hold one of the
articles W to be welded. represents a clamp secured at one end of box A and
insulated therefrom to hold the other articlu W to be welded. D represents a man-
hole provided with tight-fitting cover, through which the article W may be passed
into the box, A. K and K represent electrical conductors, which connect the polus of
an electrical generator with the clamps F and F¹.
H represents a bracket secured to the end of box A, having thereon a serow-nut, in
which meshes a screw G, provided with a crank I, by which the box E may be moved
in either direction.
J represents a pipe connected with box A, by which said box may be exhausted of
air and then filled with some non-oxidising melium. Any non-oxidising medium may
ba employed such as hydrogen gas, nitrogen, hydrocarbon gas, solution of caustic
alkali, etcetera including any medium which retards the formation of osides and
scale upon and within the metal which is being welded. This medium may be used
under pressure or under ordinary atmospheric pressure or rarufied. If n liquid
medium be used, the cover a is of course unnecessary, the box A being filled with the
liquid, so as to submerge the articles to be welded.
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 :-
1. The method of welding together two metal rods or bars, the same consisting in
placing the articles to be welded in an electrical circuit, closing said circuit, then
breaking the circuit between the articles to be welded, whereby the voltaic are is
formed at the point of the weld, pressing the articles together, and holding them per-
manently in contact after the ends or edges have reached a welding heat, and passing
heating-currents through the articles while so pressed and held until they are welded
one to the other, substantially as described.
2. The process herein described of welding, which consists in electrically welding
metals together in a non-oxidising medium.
3. The apparatus for welding together two pieces of metal, combined and arranged,
substantially as herein described.
Dated this 7th day of May 1890.
WM. F. THOMPSON & CO.,
Agents for tho Applicant.