Improvements in Methods of and Apparatus for Heating, Forging, and Welding Metals, for Heating other Electrically Conducting Bodies, and for Producing Light by the Electric Arc.
Year: 1895

page_text: Date of Application, 17th Apr., 1895-Accepted, 17th Apr., 1896
:
COMPLETE SPECIFICATION.
Improvements in Methods of and Apparatus for Heating, Forging,
and Welding Metals, for Heating other Electrically Conducting
Bodies, and for Producing Light by the Electric Arc.
I, GEORGE DEXTER BURTON, a citizen of the United States of America,
residing at 7 Water Street, Boston, in the County of Suffolk, in the State of
Massachusetts, United States of America, Electrician, do hereby declare the
nature of my 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 the heating of metals by electricity for forging,
shaping, rivetting or welding operations, also to the smelting of ores and fusing
of metals.
The invention consists principally in the art of working metal which consists in
immersing or partially immersing the metal in a watery liquid and subjecting it to
the heating action of an electric are formed between it and the liquid until it
attains the required degree of plasticity, and then subjecting it to a forging,
welding or shaping operation. One advantage of forming a heating arc between
the metal and the liquid is that the are at once adapts itself to the shape of the
metal and surrounds or partially surrounds it, whereby a quick and uniform heating
effect is attained. Another advantage is the exclusion of oxygen and prevention
of oxidation or scaling of the metal.
The invention consists further in apparatus and implements for practising the
invention.
Figure 1 of the accompanying drawings represents a plan of an apparatus for
carrying out this process in metal working.
Figure 2 represents a longitudinal section of a work holder for supporting
rivets and other articles. Figure 2' represents a vertical section of an automatic
clamp for the work.
Figure 3 represents a longitudinal vertical section of one form of vessel for
containing the solution or bath used in this process.
Figure 4 represents a perspective view of a non-conductive hearth adapted to
support articles to be heated.
The same reference numerals indicate the same parts in all the figures.
This apparatus comprises a vessel 10, for containing an electrolytic solution 20.
This vessel, preferably in the form of a tank, is constructed of or lined with a
material which is a non-conductor of electricity. It is preferably composed of
porcelain or fire clay or earthenware lined with porcelain, and to protect it against
breakage it is surrounded by a wooden jacket 11.
The tank may be provided with a porous partition inclosing the positive plate
and protecting it from contact with the work, while permitting the passage of the
electric current. The tank may be made in small portable form, so that it can be
readily carried about and constitute a portable forge.
An electrolytic bath 20 is disposed in, the vessel 10 and partially fills it. This
bath consists of any suitable electrolyte having a density greater than that of
water and capable of evolving hydrogen, being an electrolyte which will cause
with the electric current under proper conditions the formation of a voltaic arc
between the metal to be heated and the solution.. It may consist of an acid or an
alkaline watery solution, preferably the latter.
1

page_text: The solution preferably consists of water, carbonate of soda and borax in the
proportions of three quarts of water, twelve pounds of carbonate of soda and
one pound of borax. A bath of this character does not give off offensive gases
and does not form objectionable films on the surface; nor injure the metal being
heated.
Instead of the solution described I have used a solution of sodium carbonate or
sal-soda of a specific gravity of 1.305 at 84 degrees Fahrenheit; also a solution of
equal parts of sal-soda and potassium bitartrate or cream of tartar of a specific
gravity of 1.255 at 77 degrees Fahrenheit.
An anode plate 30 is disposed in the tank and has a contact surface with the
liquid, much greater than the area of contact of the article to be heated. This
plate is composed of lead, copper, carbon or other suitable conductive material
and it is preferably in angular form, one part resting on the bottom of the tank
and the other part being parallel with one end thereof. A fixed rod 31 extends
from said plate to the top of the tank, being provided with a binding post 32 and
a conductor 33 is secured to said binding post and connected at its other end to a
positive pole of an electric source.
A conductive rest 40 is disposed at one side or one end of the tank, being
preferably supported in brackets secured to one end of the tank. A conductor 45
is secured at one end to this conductive bed and is connected at its other end to the
negative pole of an electric source.
A work bed 50 for the metal to be heated is disposed in the tank 10 and its
surface 51 is normally above the plane of the surface of the bath 20.
This work
rest is composed of non-conductive material, such as fire clay, stone, or slate,
preferably the latter. Its upper surface 51 is preferably corrugated, serrated or
otherwise roughened in some way so that parts thereof are elevated above other
parts. This non-conductive bed serves as a rest for the metal to be heated and
its corrugated or roughened surface permits the liquid to intervene between the
metal and the bed, whereby an arc or arcs are formed on the underside of the
metal.
A conductor 60 serves to connect the metal on the work bed 50 with the negative
pole of the electric source, said conductor bearing on the conductive rest 40
through which the current passes. This conductor 60 is preferably in the form of
a pair of tongs, the jaws grasping or touching the metal to he heated, and the
handles being disposed in contact with said rest.
.
As before stated, the surface of the work bed 50 is normally above the surface
of the bath 20, and any suitable means are provided for shifting vertically one of
said surfaces with reference to the other so that the metal on the bed and the
liquid of the bath are brought into electrical connection. In the instance
illustrated in the accompanying drawings the surface of the bath is elevated
and depressed relatively to the surface of the bed. Any suitable means may be
employed for this purpose. The means herein shown comprise a plunger barrel 70
opening into the tank 10, and preferably formed in the tank by a partition 12
dividing off a portion of said tank, and a plunger 71 adapted to fit and play
within this plunger barrel. A rod not shown connected with said plunger extends
through a stuffing box in the bottom of the tank, and is connected at its lower end
to the slotted end of an actuating lever 73, which is preferably in the form of a
pedal lever pivoted on a suitable support, as 74. In the construction shown in
Figure 3 a plunger rod 75 connects with the slotted inner end of a lever 76
pivoted to a bracket 77 attached to one end of the tank and a rod 78 connects
the outer end of said lever with the pedal lever 73. A dynamo 90 is illustrated in
Figure 1 as the source of current and an ammeter 91 and voltmeter 92 are disposed
in the circuit.
In the use of this apparatus, as shown in Figure 1, for carrying out the method
described, the metal to be heated, as for instance a horse shoe 100, is placed on the
work bed 50 by means of a pair of tongs 60, the handles thereof being in contact
with the conductive rest 40 and the jaws being in contact with the metal. Then

page_text: the pedal 73, or other actuating device, is depressed sufficiently to cause the
plunger 71 to elevate the surface of the liquid so as to first submerge the metal:
on the bed 50 and wet its entire surface, and then the pedal is slightly raised so
that the surface of the liquid is lowered to merely form contact with the underside
of the metal on the bed or to a point sufficiently near to said metal to maintain an
electric arc between it and the liquid. This contact of the liquid with the metal
closes the circuit and an electric arc or arcs are formed between the metal and the
liquid, which arcs serve to quickly heat the metal to a red, white or fusing
temperature as desired..
The current used has a voltage of from one hundred and twenty to five hundred
and an amperage of from six upward according to the size or quantity of the
metal being heated.
When the metal being heated is sufficiently heated to place it in the desired
condition, the pedal or other actuating mechanism is released and the surface of
the liquid is permitted to fall below the metal and it can then be removed and
utilized as desired. This remark applies to the metal which is heated on the
hearth.
In another use of the process and apparatus, a work holder as 130, which is
shown in the drawings as provided with holes adapted to hold rivets, is connected
by a conductor 131 with the negative pole of the electric source and held over the
liquid so that the rivets, as 135, supported in said holder, may become partially
inimersed in the bath, and an electric arc is formed between said bath and the
immersed portions of said rivets or other articles and the latter are quickly heated
at the desired points, the said holes being surrounded by raised rims. The work
holder is as shown provided with an insulated handle.
In Figure 1 I have shown a work holder 140 supported on the work rest 40 and
on the partition 12, so that the rivets or other articles held by said work holder
project into the bath.
In another use of the method and apparatus, ore may be placed upon the work
bed or hearth and the metal contained in said ore' will become smelted and
separated from the ore by placing a conductor, as 80, in contact therewith and
holding it in close proximity thereto, so that an electric arc is formed and sustained
between it and the ore.
In another use of the apparatus, the metal or body constituting electrodes to be
heated in the form of a bar as 120, or otherwise, may be held in the hand and
placed in contact with the conductive work rest 40 and is then projected into the
bath 20 as shown at the right hand end of Figure 1, and that portion of the bar
which is immersed in the liquid is immediately surrounded with a gas envelope and
an electric arc is formed between the metal and the bath, which instantly heats
the metal to the desired temperature. In that case the surface of the solution
need not be elevated.
In another use of the device, a bar, as 300 is projected through an automatic
clamp 170 connected with the negative pole of an electric source and its end is
projected into the liquid and heated, being withdrawn when sufficiently heated.
The automatic clamp may comprise a fixed jaw having an eye 171 through which
the bar to be heated is projected, and a movable jaw 172 in the form of a pin
which projects through a hole transversely to said eye. This movable jaw may be
weighted by a ball 173 adjustable thereon, which ball may be used to regulate the
position of the movable jaw with reference to the lower side of the eye, as shown
in Figure 2, being raised more when thick bars of metal are to be passed
through the eye. The eye preferably flares at its outer upper edge and its
lower inner edge whereby the bar may be adjusted at any desirable incline in
the eye.
In another use of the device the bar, as 150, is held in a pair tongs or holder 160,
which is connected with a negative pole of an electric source, and another bar
as 151 is held in contact with the bar 150 and the ends of said bars are projected
into the solution or bath beyond their point of contact and both bars are heated

page_text: and may be forged, or welded together. In this case the bar 151 receives current
from the bar 150. Both pieces are thus connected with the negative pole of the
electric source.
This apparatus constitutes a very convenient forge for a blacksmith and also
an economical one as no current is employed when the article is not being
heated.
The term metal as used in the Specification and claims is intended to include
that substance in any form.
In this process of electric bath metal working the solution itself might be said
to constitute one of the electrodes, and being flexible it surrounds the bar or metal
to be heated and an arc or luminous film is formed around all the submerged part
thereof, whereby said bar is uniformly heated throughout. The work, constituting
the negative electrode, offers a much higher resistance than the other metallic
electrode or anode, and while the arc or luminous film is formed between the
work and the liquid electrode, the current passes from the positive metallic
electrode to the liquid electrode without incandescence or luminosity. If the
process of heating is conducted with a proper current, one say having a voltage
of from one hundred and ten to five hundred and an amperage of from sixty
upward, and with the electrodes the proper distance apart, the hydrogen set free
at the work, which constitutes the cathode, opposes the passage of the current
with such resistance that it will soon become incandescent, as may be readily seen,
by looking down into the fluid, where a stream of the hydrogen bubbles should be
visible passing between the liquid electrode and the inetal surrounded thereby.
The incandescent hydrogen is thus made to reinforce the direct action of the
heating electric current and it will be found that the heating of the metal in
this way will clean off the oxidation on the surface of the metal when the process
is finished, as for example, with the rivets shown. This enables them to make a
better and closer job of rivetting than otherwise.
The work calls for the current which is required to heat it; that is to say the
apparatus being capable of supplying sufficient current to heat the larger pieces
required to be heated, when such a piece or pieces are placed in circuit with the
bath, they will take the maximum current; when a smaller piece or pieces are
placed in circuit the quantity of the current passing through the line is reduced.
The current is thus regulated by the size of the piece or pieces being heated and a
rheostat or other means of regulation is dispensed with. The metal bars to be
heated are held as near the surface as practicable, being submerged sufficiently to
cover the parts to be heated, and to cause the formation of the hydrogen jacket
and the voltaic arc.
The piece held in the hand of the workman can be readily manipulated and as
he holds it above the point of connection with the circuit and has connection with
one pole only danger of shock is avoided.
Whenever a bar or metal or other body constituting a negative electrode or
cathode is immersed as herein before described or partially immersed in the solution,
an arc is formed as aforesaid, and the arc produces light.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. The art of working metal, which consists in forming a voltaic arc between the
metal and a watery liquid, the metal constituting the negative pole and the liquid
the positive pole, and subjecting the metal to the beating action of said are until it is
raised to the forging heat, then withdrawing said metal from the liquid and
subjecting the heated metal to a forging or shaping operation.
2. The art of electrolytic metal working which consists in forming a voltaic arc
between the metal to be worked and an electrolytic solution, the arc impinging at
one of its terminals on the metal to be heated and at its other terminal solely on
the solution and subjecting the metal to the heating action of said are until it is

page_text: raised to a working heat, then withdrawing the metal from the solution and
subjecting it to a metal working operation.
3. The art of electrolytic metal working which consists in immersing or partially
immersing the metal to be worked as a cathode in a solution containing or con-
stituting the anode, passing an electric current through said solution and forming
a voltaic arc below the surface of said solution surrounding the submerged metal,
the arc impinging at one of its terminals on said metal and at its other terminal
solely on the solution; and subjecting the so heated metal to a metal working
operation.
4. The art of working inetal which consists in submerging the work in an
electrolytic bath, said work constituting the negative electrode and offering a much
higher resistance than the positive metallic electrode in sail bath, and passing an
electric current through said bath and work, said bath serving as a flexible
electrode, said current being of such a character as to form an electric arc
surrounding the work between it and the bath, and passing without incandescence
through the bath from the metallic anode.
5. The art of heating metal which consists in supporting the metal upon the
surface of a non-conductive bed above the surface of an electrolytic bath, then
shifting vertically the horizontal plane of one of said surfaces and bringing the
bath and metal into electrical connection and passing an electric current through
the metal and bath, said current forming an electric arc or arcs between the metal
and the liquid of the bath.
6. The art of heating metal, which consists in submerging or partially sub-
merging it in a bath consisting of an aqueous solution of carbonate of soda, and
borax, then passing electric current through said metal and solution and forming an
incandescent gas envelope or voltaic arc around the immersed metal.
7. The art of heating metal which consists in supporting it above the surface of
an electrolytic bath, then elevating the surface of said bath into contact with said
metal and permitting the metal to protrude above the bath, and passing an electric
current through said article and bath, said current forming an electric arc between
them.
8. A portable tank provided with a porous partition and with a bracket at one
side serving as a rest for the work or work-holder.
9. A portable tank for heating metals provided with a porous partition and with
a bracket at one side serving as a rest for the work or work-holder, said rest
constituting one terminal of the tank.
10. A movable work bolder connected with an electric conductor and provided
with an insulated handle and with holes for holding the metal to be heated.
11. A movable work holder connected with an electric conductor and provided
with an insulated handle and with holes for holding the metal to be heated, said.
boles being surrounded by raised rims.
12. A tank for heating metals provided with electric connections and with a
bracket at one side which serves as the rest for the work, said rest constituting one
of the electric terminals of the tank.
13. The combination of a vessel, an electrolytic bath therein, a non-conductive
bed upon which the metal rests to be heated, the surface of said bed being above
the surface of the bath in their normal relations, conductors for connecting said
bath and metal with opposite electric poles, and means for elevating and depressing
one of said surfaces to bring the bath and metal on the bed into electric connection
and separate them at will.
14. The combination of a vessel, an electrolytic bath therein, a non-conductive
bed for the metal to be heated provided with a roughened surface, the surface of
said bed being above the surface of said bath in their normal relations, means for
elevating and depressing one of said surfaces to bring the bath and metal on the
bed into electrical connection and separate them at will, and conductors for
connecting said bath and metal with opposite electric poles.
15. The combination of a vessel, an electrolytic bath therein, a non-conductive

page_text: bed for the metal to be heated, and means for establishing an electric arc between
the bath and the metal on the said bed.
16. In an electrolytic bath metal heating apparatus, the combination of a
non-conductive bed provided with an irregular surface.
17. The combination of a bath, an automatic clamp for receiving a bar to be
heated in said bath, and conductors for connecting said bath and metal holding
device with opposite electric poles.
18. The combination of a tank, a bath composed of a suitable liquid disposed in
said tank, automatic clamp mounted on the edge of said tank, and means for
connecting said bath and clamp with opposite electric poles.
19. The combination of a receptacle for containing a resistance bath, an
automatic clamp mounted on the edge of said receptacle, the movable jaw of said
clamp being provided with means for regulating its action, and conductors
connecting said solution and clamp with opposite electric poles.
20. The combination of a receptacle, a bath composed of a suitable liquid
disposed in said receptacle, an automatic clamp mounted on said receptacle, the
stationary member of which is provided with an eye flared at its upper outer edge
and its lower inner edge which permits the bar to be adjusted at any desired
incline, and conductors connecting said solution and clamp with opposite electric
poles.
21. The combination of a receptacle for containing a resistance bath, an
automatic clamp mounted thereon and comprising a stationary member provided
with an eye flared at its upper outer edge and also at its lower inner edge, and a
weighted pin sliding in said eye, and conductors connecting said solution and clamp
with opposite electric poles.
22. The art of heating metal bars which consists in subjecting the parts to be
heated while in contact with each other to the action of an electric arc sprung
between them and an electrolytic bath.
23. The art of heating metal bars which consists in immersing or partially
immersing the parts to be heated in a suitable bath, and passing a suitable electric
current through said bath and bars, said bars being in contact and one receiving
current from the other.
24. The art of uniting two pieces of metal, which consists in subjecting them to
the action of an electric arc sprung between them and an electrolytic bath, and
fusing the parts together while in the bath.
25. The art of uniting two pieces of metal, which consists first in subjecting
them to the action of an electric current, in an electrolytic bath in which an
envelope of evolved bydrogen surrounds them, and secondly bringing them into
pressure contact with each other when at the proper heat until they unite,
substantially as described.
26. The art of heating two pieces of metal, which consists in immersing or
partially immersing the parts to be heated in a suitable electrolytic bath and
passing a suitable electric current through said bath and pieces, both of said pieces
being connected with the negative pole of the electric source, an incandescent gas
envelope being formed around the submerged portions thereof.
27. The art of heating metal by electricity and regulating the amount of current
consumed, which consists in immersing or partially immersing the article to be
heated in a solution and passing an electric current through said article and
solution, said current forming an arc sprung between said article and said liquid,
the article being heated determining the quantity of current and serving as a
regulator therefor whereby other means of regulation are dispensed with.
28. The art of heating metal which consists in submerging or partially sub-
merging it in a bath consisting of an aqueous solution of carbonate of soda, and
borax, and then passing an electric current through said metal and solution
forming an incandescent gas envelope or voltaic arc around the immersed metal.
29. The art of working metal, which consists in immersing or partially immersing
a metal to be worked in a bath consisting of carbonate of soda and borax, or its

page_text: equivalent, and subjecting said metal while so immersed to the action of an electric-
current until it is raised to the desired working heat, and then subjecting the
heated and softened metal to a metal working operation.
30. The art of heating an electrically conductive body, which consists in
connecting the body to be heated to one pole of an electric generator, connecting a.
suitable gas producing electrolytic bath with the other pole thereof, and then
immersing the body to be heated in said bath and developing a gaseous resistance.
sheath around the same, whereby heat is localized thereon and an arc is sprung
between the liquid and the article to be heated.
31. The art of heating a part of an electrically conductive body, which consists.
in connecting said body to one pole of an electric generator, connecting the liquid
of an electrolytic bath with the other pole of said generator, and then plunging
the part to be heated into said bath and forming a voltaic arc surrounding the
submerged portion of said body between it and said bath.
32. The art of heating a body electrically which consists in immersing the body
to be heated in a conductive liquid having in contact with it an electrode of large
superficial area compared with the body to be heated, and developing on said body.
a gaseous resistance sheath operating to convert the electrical energy into heat
and localize it on said body, said body and liquid being connected with opposite-
electric poles of the same source.
33. The method of heating an electrode which consists in immersing or partially
immersing it in a solution, passing an electric current through said electrode and
solution and forming a voltaic arc below the surface of said solution around the
submerged electrode, the arc impinging at one of its terminals on said electrode.
and at its other terminal solely on the solution.
34. The method of forming an electric light, which consists in submerging an
electrode in a chemical solution and subjecting said electrode and solution to
the action of an electric current which forms a voltaic arc between the solution.
and the electrode and surrounding the submerged portion of the latter.
35. The process of heating an article, which consists in submerging it as a
cathode in an electrolytic bath and subjecting it to the action of an electric current
which forms an electric arc surrounding all that portion below the surface of the-
bath, the current passing without incandescence from the anode to the liquid.
Dated this 28th day of March 1895.
Witnesses:
FRANCES J. BURTON.
GEO. N. BLISS.
GEORGE DEXTER BURTON..