Improvements in the Method of and Apparatus for Heating, Welding, or Working Metals by Electricity.
Year: 1894

page_text: Date of Application, 22nd May, 1894-Accepted, 27th Oct., 1894
COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Heating,
Welding, or Working Metals by Electricity.
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 improvements in the method of and apparatus for
heating, welding or working metals by electricity, hereinafter fully described and
claimed.
Figures and 3 are side elevations of apparatus which may be used to practise
the invention.
Figures 2 and 4 are sections on line z-z, Figures 1 and 3 respectively.
Figure 5 is a side elevation showing a modified form of apparatus: and
Figure 6 is a section on line -z, Figure 5.
A represents a table or support, on which is carried the material B to be heated,
which may be insulated from table A: J, a goose neck or standard rising from
table A: K, a collar at the end of standard J: N, a rod which passes through
collar K. For convenience in raising and lowering the electrodes, rod N may be
screw threaded and engage with a threaded nut M rotatably held on collar K by
lugs L, but many other ways of raising and lowering the electrodes may be used.
I represents insulation: C, a series of electrodes, preferably carbon, supported by
rod N, but insulated therefrom. Electrodes C are insulated from each other, and
each carries a contact plate G. In Figures 1 and 2, electrodes C are grouped in
a circle, and in Figures 3 and 4 they are arranged in line. D represents a movable
conductor, connected with one terminal of a generator of electricity carrying a
brush F adapted to make contact with one of the contact plates G. With the
arrangement shown in Figures 1 and 2, conductor D may be a pulley loosely
mounted on rod N, but insulated therefrom and from the electrodes C, and in
electrical contact with an insulated contact plate E which is connected by
conductor with one terminal of the generator. With the arrangement of
Figures 3, 4 and 5, plate E is made in the form of a rod on which conductor D
slides, or with the arrangement of Figure 5, in which electrode T is as long as the
combined width of all the electrodes and extends along the side of electrodes C,
and in which conductor Y is constantly in contact with electrode T, whilst the
latter can only be in circuit with one electrode C at once. Conductor D may be
directly connected with the generator, contact E being omitted. In using the
mechanism of Figures 1 and 3, the voltaic arc is formed between the electrodes C
and the material B, while in using the mechanism of Figure 5, the material B is
not in circuit.
The operation of the invention is as follows, having special reference to
Figures 1 and 3-
Material B being placed in position, the electrodes C are lowered to make
contact therewith and current is turned on, the circuit being through conductor y,
material B, one electrode C, brush F, conductor D, contact E, conductor
and

page_text: the generator. When the circuit is established, the electrodes C are raised by
nut M, and rod N and a voltaic arc is formed between material B and one of the
electrodes C. Conductor D is now moved, as by a band or belt P, Figure 1, or
by sliding it along rod E, Figure 3, cutting the electrodes C in and out of circuit
successively and causing the arc to shift its position from the end of one
electrode to the end of the next electrode, thus causing the arc to travel a
predetermined path, and rendering it easy to heat a seam of considerable length
with a very small power.
With the arrangement of Figure 5, the electrode T, which is as wide as all the
electrodes C, is brought into contact with one of the electrodes C by any
convenient means, such as shaft t and screw nut V, and then separated, forming a
voltaic arc, and then conductor D is moved, causing the arc to shift along
electrode T as electrodes C are successively cut in and out of circuit. In all cases
however the metal heated will also be heated by radiation from the incandescent
electrodes in proximity to, but not in contact with it.
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 herein described method of heating metal, consisting in subjecting the
metal to the influence of a moving voltaic are while simultaneously heated by
radiation from incandescent electrodes in proximity to, but not in contact with
the metal.
2. In an apparatus for electrically heating by means of the electric arc, the
combination of a plurality of electrodes insulated from each other, a contact device
by means of which said electrodes may be successively thrown in circuit, means
for moving said contact device, and means for maintaining an electric are between
another electrode and the first named electrodes as successively thrown in circuit.
3. In an apparatus for electrically heating by means of the electric arc, the
combination of an electrode connected to one terminal of a source of electric
energy with a plurality of electrodes insulated from each other, a contact device
connected to the other terminal of the source of electric energy, by means of
which said electrodes may be successively thrown in circuit, means for moving
said contact device and means for maintaining an electric are between said first
named electrode and said insulated electrodes, as successively thrown in circuit.
4. In an apparatus for electrically heating by means of the electric arc, the
combination of an electrode connected to one terminal of a source of electric
energy, a movable conductor connected to the other terminal of said source of
electric energy, a series of insulated electrodes adapted to be successively placed in
circuit by said movable conductor, and means for maintaining an electric arc
between said first named electrode and the insulated electrodes, as successively
thrown in circuit.
Dated this 21st day of May 1894.