Improvements in or relating to Electrically Heating and Welding Metals.
Year: 1894

page_text: Date of Application, 27th Nov., 1894-Accepted, 13th Apr., 1895
COMPLETE SPECIFICATION.
Improvements in or relating to Electrically Heating and Welding
Metals.
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 31 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 relates to improvements in the method of and apparatus for
electrically welding metals and heating the same hereinafter fully described and
claimed, reference being made to the accompanying drawings, in which
Figure 1 is a perspective view of a carbon holder connected with an improved
furnace or furnace box, the latter being in section ;
Figure 2 an enlarged sectional perspective view of the furnace, one end being
omitted;
Figure 3 a section through one part of the furnace box looking downward and
Figure 4 a top plan view of the furnace box with the inner plate removed and
showing a slight modification in construction.
Figure 5 is a perspective view of a complete machine for welding metals, devised
with special reference to welding rings such as hub bands and other forms of
hoops;
Fi
Figure 6 a side elevation partly in section of the same and
Figure 7 a perspective view of the clamp and movable anvil;
Figures 8 and 9 are side elevations partly in section of an improved apparatus
for heating metals electrically and Figure 10 a side elevation of a modification.
In heating metals by the action of a voltaic are, in a furnace, the intense heat
tends to disintegrate the furnace, and it is found that a furnace of considerable life
can be made as follows:-Referring to Figures 1 and 2, A A represent soup-stone
slabs or slabs of slate, lava, or any suitable material, which is for ordinary purposes
considered a refractory non-conductor of electricity, forming insulating slabs, which
form the sides and ends, and top or bottom of the furnace, the bottom slab being
omitted in Figures 1 and 2. It will be noticed that the insulated slabs A A shown
in Figure 2, project somewhat below the other parts of the furnace so that when
the bottom slab is put in position and is secured by bolts engaging with threaded
B represent>
sockets, it will not come in contact with any of the interior linings
the slabs of carbon, or mixtures of carbon with clay, or may be such mixtures as
are known as carbon brick, or graphite brick, but which for the purpose of this
invention fulfil all the requirements of a slab of pure carbon, two of which are
secured to the insulating sides A by a screw bolt a, taking into a threaded socket b.
The inner slab is recessed as shown, to receive the head of bolt a and protect it
from the fire. The aperture C through the insulating sides A is continued through
the carbon slabs B, but made larger through said carbons for the purpose of
preventing contact between the carbons between which the voltaic arc is formed

page_text: and said slabs, the hole C being made of such size through the insulating sides as
to be somewhat snugly closed by the arc carbons. D represents a refractory block
such as lime or magnesia or graphite cut to fit between the inner carbon slabs B and
provided with shoulders to engage with the recess in said carbon slabs and thus
protect the heads of bolts a. While the insulating slabs may be threaded to
receive the bolts which fasten the sides and top or bottom of the furnace together
firinly it is preferred to screw into said insulated slabs a thimble c which is screw-
threaded on its outside to engage with the bolt, whereby repeated operations of the
bolt or screw do not tend to wear off the threads on the insulated slab. As shown
in Figure 3, three sides of the furnace indicated by E, may be made of iron,
the other side E¹ being also made of iron and connected with the remainder of the
box by screw bolts which pass through insulation which is also interposed
between the sides E and E¹, as clearly shown in the figure. If this iron box is
used, instead of the insulating slabs, it is advisable for the purpose of preventing
short circuiting that the carbon slabs B, with which the side El is lined, shall not
be in electrical contact with any other of the carbon slabs B lining the other part
of said box, as clearly shown in said drawing. In Figure 4 the insulating sides A
are retained for three sides and the fourth is made direct by two carbon slabs B,
the outer one of which may be recessed to form an air space between them, as
shown in the drawing, and in this construction care should be taken that said
carbon forming one side of the furnace preferably should not come in electrical
contact with any of the carbon slabs lining any other side of the furnace.
Figure 4, the outer side containing the air space is secured in position by bolts e¹
engaging threaded sockets b. By keeping all of the carbon slabs B on the
different sides of the furnace out of electrical contact with each other, a short
circuit between the arc forming carbons is prevented, as this would interfere with
the maintenance of the voltaic are in its proper location. It is found by repeated
trials that a furnace lined in this way with a refractory top, such as lime or
magnesia, or graphite, and double carbon slabs at the sides will last under continued
use for a long time, the only thing which requires renewal being the inner carbon
slabs, and by the construction shown these slabs can be usually renewed at the end
of 30 or 60 days, or whenever too much eaten away by simply unscrewing the
bolts e and a, and putting a new carbon in place.
In
The furnace or furnace box, constructed as described, may be used in connection
with the carbon holder exhibited by Figure 1, where the letters F F represent
two carbon holders, whose upper ends form nuts G, one of which is tapped with a
right hand screw thread, while the other is tapped with a left hand screw thread,
to engage with screw threads on shafts H, said screw threads being of different
pitch, and both nuts G are bored to fit and slide on guide rods g g². H represents
a shaft journaled in heads ff, and lugs lying between guide rods g g and
provided at one end with a hand wheel G'. The ends of shaft II outside of
lugs hare right and left-hand screw threaded, the pitch of one of said screw
threads being about double that of the other, so that when by rotation of said shaft
the nuts G are moved, the motion of one of said nuts will be faster than the motion
of the other, so that one of the carbon holders carried on said nuts will advance
faster than the other to compensate for the greater rapidity of combustion of the
positive carbon. The carbon holders are adapted to hold carbons which project
into the furnace or furnace box through the passages C, the construction being
such that the arc can be regulated.
Figures 5, 6 and 7 show a complete machine for welding metals having the
aforementioned furnace and carbon holder.
I represents a skeleton table, carried on suitable legs. J represents a shaft
journaled in brackets j on the under side of the table I and provided at one end
with a hand wheel J'. K represents a wheel on shaft J meshing with a pinion k
on shaft K and engaging with a rack L secured on the underside of a boss M,
supported by wings mm² on table I, so as to slide freely thereon, when said rack L
is moved.

page_text: L' represents a shaft fastened on the back part of table I, by lug l, and bolts l.
which extends through boss M to guide the same in its travel, and also extends
through, and guides and supports an anvil O, which is connected by a bar O' with
an upright plate P on boss M, and slides on shaft L'.
P P' represent the two parts of a ring clamp which are partially supported by
wings ppl on table I, and which each have a threaded lug o, right and left hand
screw threaded respectively, to engage with a right and left hand screw threaded
shaft Q, journaled in table I, and provided with a hand wheel Q', by which shaft Q
may be rotated to either draw the two parts of the clamp together or separate
them. In Figure 7, the hand wheel Q₁ is represented at the left of the screw
shaft Q.
R represents a furnace, or box of refractory material, slidingly supported on
plate P, into the interior of which project from opposite sides a pair of carbons B
carried in holder F', provided with a screw shaft H and hand wheel G', as shown
in Figure 1 by which said carbons may be brought together or retracted from
each other, it being understood that said carbons are to be connected with the poles
of a generator of electricity.
R' represents a screw shaft threaded in a lug, on furnace R, bearing on the
support P, by which said furnace may be raised or lowered, a hand wheel
connected with said screw shaft R'.
S represents a hub band in position in the machine.
The operation is as follows:-
being
A piece of metal, bent into the form of a hoop, is inserted into clamps P¹ P³, the
joint coming in the open space at the top of said clamps, and is then clamped so
as to be securely held, by rotating shaft Q.
Shaft J is now rotated so as to first pass anvil through the hoop S, and to
bring furnace R over the joint of said hoop, when, an arc being established
between carbons B, the metal at each side of the joint is rapidly brought to a
welding heat and as soon as this is accomplished shaft J is rotated in the opposite
direction, moving furnace R away from the hoop, and bringing anvil O under the
joint, when the joint can be readily and rapidly finished by a hammer.
Figures 8, 9 and 10 represent three different forms of apparatus for heating
metals electrically. In these
T represents a table or support for the material to be heated, provided with a
standard T¹. tt represent insulated arms carried on and projecting from
standard T.
In Figures 8 and 9, the arm & terminates in a collar U, which serves as a journal
for an upright shaft U', which is supported and rotated by a belt pulley u, clamped
to shaft U', and resting on collar U. The shaft U carries at its lower end an
electrode V, which in Figure 8 is clamped in the lower end of said shaft by a set
screw V, eccentric to the axis of revolution of, and parallel with, the shaft U¹,
and in Figure 9 is clamped at right angles with said shaft.
Arm terminates in an annular clamp W, within which is clamped a hollow
electrode V, preferably made of carbon.
W, Figure 8, represents a sheath for electrode V, which may be either of some
refractory material or may be a metal or magnetic sheath.
W2 represents a magnet carried on electrode V and included in au electric
circuit, which may be a shunt of the main circuit, or a separate circuit, the office
of said magnet being to deflect downwards a voltaic are formed between
electrodes Vand V, and this magnet may or may not be used, at will.
X represents insulating material in all cases.
v represents a conductor connecting arm with one terminal of a generator of
electricity, and to represents a conductor connecting arm t¹ with the other terminal
of said generator. V' represents the material to be heated, represented in
Figures 8 and 10 as a plate of metal, and in Figure 9 as the end of a drum with a
flanged head, to be welded thereto.
In Figure 10, the arm is omitted; the electrode V' is solid passing through

page_text: collar U, and held in position by a clamp V', to which is connected conductor v,
resting on the top of said clamp, and in this instance the collar U is insulated from
electrode. Belt pulley u is journaled on and is in electrical connection with
collar U, and has a bent arm y which carries at its ends the electrode V, pointing
towards the lower end of electrode V³.
W
represents a magnet carried on electrode V, and in this arrangement the
terminals of the bobbin of the magnet may be carried up inside of the belt pulley,
and lead out above said pulley.
The operation of this part of the invention is as follows:-
An electrical circuit being established, a voltaic arc is formed between
electrodes V and V2, either by bringing them in contact and then separating
them, or by bridging between them with a fusible conductor. Belt pulley u is
then rotated, rotating the movable electrode V, thus carrying the voltaic arc
around the inner periphery of electrode V in Figures 8 and 9, and the outer
periphery of electrode V' in Figure 10.
The material V' to be heated is brought in proximity to the rotary voltaic arc,
by which it is rapidly heated. The heating effect may be aided by the action of
the magnet W' forcing the voltaic arc towards the material.
In addition to the heating effect of the arc, the lower end of the electrode V2
becomes very highly heated, (to incandescence usually). and its radiated heat acts
powerfully upon material V³.
Having now particularly described and ascertained the nature of the said
invention, 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. A furnace for electrically heating metals, consisting of a box composed of
separable parts, secured together by bolts, having its sides and ends lined with
double slabs of carbon, the lining of the sides and ends being insulated from each
other, and having its top or bottom, as the case may be, lined with a refractory
slab, such as lime, magnesin or graphite, substantially as shown and described.
2. A furnace for electrically heating or welding metal, consisting of a box
formed of the refractory insulating slabs A provided with threaded sockets c,
secured together by bolts el, and liued with the carbon slabs B secured in position
by the bolts a and threaded sockets b, and the lime or magnesia top or bottom,
substantially as shown and described.
3. In an apparatus for electrically heating metal, the combination of a separable
clamp for holding the article to be welded, means for opening and closing the
clamp, a movable furnace, a movable anvil, and connecting mechanism for
moving the furnace towards the clamp, and moving the anvil in proper relation to
the clamped article, substantially as described.
4. In an apparatus for electrically heating metal, the combination of a separable
clamp approximately conforming to the article to be held, and composed of two
independent parts, with guiding ways for the independent parts, and a right and
left threaded shaft engaging with lugs on the parts of the clamp for moving the
said parts, with a movable furnace, and an anvil, which is moved towards and
from the clamp as the furnace moves, substantially as described.
5. In an apparatus for heating metals electrically, the combination of a support,
a separable clamp approximately conforming to the article to be held, and
composed of two independent parts, means for opening and closing the parts of
the clamps, a furnace movable towards and from the clamp, and an anvil placed in
proper relation to the clamp as the furnace moves away from said clamp, substan-
tially as described.
6. In an apparatus for heating metals electrically, the combination of a support,
a separable clamp approximately conforming to the article to be held, an anvil,
and a movable furnace adapted to subject the clamped article to heat and place
said article in proper relation to the anvil as the furnace moves away from the
clamp, substantially as described.

page_text: 7. In an apparatus for electrically heating metal the combination of a stationary
and rotary electrode, with means for revolving one of said electrodes about the
other electrode.
for
8. In an apparatus for electrically heating metal the combination with the metal
to be heated, of a stationary electrode, a rotary electrode and means
maintaining an electric arc between said electrodes.
9. In an apparatus for electrically heating metal, the combination with the metal
to be heated, of a stationary electrode, a rotary electrode, means for maintaining
an electric arc between said electrodes, and a magnet for deflecting or directing
said arc.
10. In an apparatus for electrically heating metal, the combination, with the
metal to be heated, of two electrodes, ineans for rotating or revolving one of said
electrodes, with means for maintaining an electric arc between said electrodes.
11. In an apparatus for electrically heating metal, the combination, with the
metal to be heated, of two electrodes, means for rotating one of said electrodes,
an electric are maintained between said electrodes, and a magnet for deflecting or
directing the arc.
12. In an apparatus for electrically heating metal, the combination with the
metal to be heated, of a solid electrode, meaus for rotating a second electrode
about said first named electrode, means for maintaining an electric arc between
said electrodes, and a magnet for deflecting or directing said arc.
Dated this 26th day of November 1894
WM. P. THOMPSON & Co.,
Agents.

page_text: Date of Application, 27th Nov., 1894-Accepted 18th May, 1895
Improvements in the Method of and Apparatus for Electrically
Heating Metal or other Conducting Bodies.
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 31 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 :-
My correspondent some time ago discovered that by connecting a body to be
heated with one terminal of a source of electric energy, and then bringing said
body in circuit with a liquid electrode connected with the other terminal of said
source of electric energy, the solid electrode could be heated, but he also found
that this method required an undue expenditure of mechanical and electrical energy
for the result attained.
He then discovered that by heating the solid electrode to about the boiling point
of water before bringing it in circuit, a rapid heating effect was attained with
comparatively small expenditure of mechanical and electrical energy, and also that
by using a liquid electrode, the liquid or solution of which contains a substance
which volatilises or evaporates at a comparatively low temperature, the solid
electrode could then be heated rapidly and economically by putting it in circuit
with the liquid electrode without first heating the solid electrode.
This volatile or vaporable constituent acts in two ways, first in surrounding the
metal or substance to be heated with a gaseous or vaporous film or envelope which
assists in establishing the arc and may primarily provide high initial resistance, and
second provides the arc with an inflammable or conducting gas or vaporous medium,
thereby assisting in securing steady maintenance of the arc, and in supplying the
arc with a conducting gas.
He is aware that in the method of heating metal by immersion in a liquid or
electrolyte, electrolytic oxygen or hydrogen gas is evolved, us the case may be, and
may surround the immersed portion of the metal to be heated; this gas does not
perform the function of the volatile or vaporable constituents of the electrolyte
as the invention herein described, being evolved only by electrolysis, whereas the
volatile or vaporable body is volatilised or vaporised by the spark at contact, by
the heat owing to high initial resistance, and ultimately by the combined heat of
the heated electrode, and the arc.
This volatile or vaporable constituent also may act in increasing the conductivity
of the electrolyte, and when volatilised or vaporised may increase materially the
conductivity of the arc and its gases or vapors.
For the purposes of the present invention, it is found that a saturated solution of
borax, carbonate of soda, carbonate of potash, either singly or in combination, to
which has been added acetic acid, acetate of potash, phenol, acetone glycerine,
methyl alcohol, singly or in combination, will provide an electrolyte having
sufficient conductivity and affording a volatile or vaporable medium. The
proportion of acetone glycerine or volatile bodies may be varied to suit, and they

page_text: may be supplied to the electrolyte when from long usage or other reasons the
electrolyte has become depleted.
The following is a list of the solutions which may be used, though probably it
does not comprise all. To 3 gallons saturated solution of carbonate of potash one
half gallon of glycerine may be added to form the electrolyte; or where it is desired
to still further increase the volatile constituent, the glycerine may amount to one
gallon to three of saturated aqueous solution of carbonate of potash.
A mixture of one pound acetic acid to three gallons of water may be used; or
one pound acetic acid to a solution of acetate of soda composed of three gallons of
water and two pounds acetate soda.
To three gallons saturated aqueous solution of carbonate of soda the addition of
one pint of methyl alcohol forms a convenient electrolyte.
A suitable liquid electrolyte is formed by adding one pint of methyl alcohol and
two pints of glycerine to three gallons of a solution of caustic potash of sp. gr. 1210
at 80 degrees Fahrenheit.
A solution of sal soda, cream of tartar, equal parts in water, to sp. gr. of 1255
at 75 degrees F. to 3 gallons of which one half gallon of glycerine has been added
forms another good electrolyte.
There are many other substances or chemicals which would suggest themselves
to chemists or those skilled in the art, and various combinations of these
substances could be made to increase or decrease the conductivity of the
electrolyte.
In the drawing, Z represents a vessel, either insulated or placed on some insulated
support, containing the above described solution marked Z', which solution is
connected by a conductor z, either through the medium of the vessel itself or by
said conductor making contact with the solution, with one terminal of a source of
electricity.
Z represents a cover or bridge on vessel Z, insulated therefrom by insulating
material X, and connected by conductor x with the other terminal of the
generator.
Z represents a solid electrode, the thing chosen for illustration in this case
being a rivet, to the heating of which this method and apparatus are particularly
suited.
Electrode Z³ makes contact with bridge or cover Z³, and is held by said bridge
or cover so as to dip just the proper distance desired to be heated, into the liquid
electrode Z¹.
Of course the bridge or cover may be omitted, and the electrode may be grasped
by a pair of tongs connected with conductor and immersed by hand.
With this process an alternating current can be used to advantage, probably
because the gaseous envelope surrounding the electrode to be heated, is not
dependent upon electrolytic action. In practice it has been found necessary to use
a continuous current and preferably connect the metal to the negative pole, to
secure good action, in the first mentioned process used prior to this invention, and
it has been found impracticable to use an alternating current in such old process.
With the present process above described the metal may be connected to either
terminal and either a continuous or alternating current may be used.
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 electrically heating metal, and other
conducting bodies consisting in bringing the metal in circuit with a liquid electrode
containing a substance more volatile or vaporisable than water.
2. The herein described method of electrically heating metal, and other
conducting bodies consisting in springing an electric arc between the electrode to
be heated and a liquid electrode or electrolyte containing a substance more volatile
or vaporisable than water.

page_text: 3. The herein described method of electrically heating metal, and other
conducting bodies consisting in putting the electrode in circuit with a liquid
electrode containing a substance more vaporisable or volatile than water, whose
volatile constituent is inflammable.
4. The herein described method of electrically heating metal, and other
conducting bodies consisting in springing an electric arc between the electrode and
a liquid electrode or electrolyte containing a substance more volatile or vaporisable
than water whose volatile constituent is inflammable.
Dated this 26th day of November 1894.
WM. P. THOMPSON & Co.,
Agents.