Improvements in the Methods of and Apparatus for Working Metals by Electricity.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in the Methods of and Apparatus for Working Metals
by Electricity.
I, GEORGE DEXTER BURTON, of 194, Washington Street, Boston, in the County
of Suffolk and State of Massachusetts, United States of America, Inventor and Car-
builder, 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 a method of and apparatus for working metals, in which
electricity is employed as a heating agent for softening the metal to be worked.
The invention has special reference to methods and apparatus for working a
succession of articles from a metallic bar.
The principal objects of the invention are to avoid repeated heating of the bar from
which the articles are produced; to secure a proper regulation of the electric current ;
and to separate the electrodes from the forging or shaping mechanism.
The invention consists in the method of making a forging by forming a blank of a
determinate size for the forging to be produced; then softening said blank by passing
an electric current therethrough; then cutting off said current and feeding the
softened blank to the working dies; and then subjecting the blank to a forging or
shaping operation.
The invention consists further in a bar feeder; a bar cutter for cutting off a blank
from the bar being worked; a metal working mechanism; and an electric heater
disposed between the cutter and the metal working mechanism for heating the blank
after it is cut from the bar and before it is subjected to the forging or other metal
working mechanism; whereby that portion only of the material to be. worked is
subjected to the electric current and repeated heating and re-heating of the bar
avoided. The electric heater may also serve as a feeder for feeding the blank to the
working mechanism, or a separate blank-feeder may be employed.
The invention consists further in the combination of forging dies; a feeder for
feeding the metal to be worked to said dies; electrodes for heating said metal while
out of contact with the dies; an electric circuit connected with said electrodes, and a
variable resistance in said circuit between the source of electricity and said electrodes
for regulating the current passed through said metal while out of contact with the dies.
The invention consists further in certain combinations of parts hereinafter set forth
for carrying out the process herein described.
Figure 1 of the accompanying drawings is a front elevation of a forging machine
adapted for use in connection with my improved electric heating and feeding
mechanism, the electrodes and their supports being omitted.
Figure 2 is a rear elevation thereof.
Figure 3 is a side elevation thereof showing the bar-heater, and the electric circuit
provided with resistance coils.
Figure 4 is an enlarged vertical longitudinal section of a portion of this improved
metal working apparatus and its appurtenances, the forging mechanism being on line
4-4 of Figure 1.
Figure 5 is an enlarged horizontal section thereof on line 5-5 of Figure 3.
Figure 6 is a diagram representing a variable resistance circuit, and my improved
blank-supporting electrodes disposed therein.
Figure 7 illustrates one species of the electrodes used in this apparatus.
Figure 8 represents a vertical section of the cutting-off dies.
Similar numerals of reference indicate corresponding parts in the different figures.
Any suitable metal forging or shaping mechanism may be employed in connection
with my improvements. The mechanism herein illustrated for this purpose is a drop

page_text: forging machine. The frame of this machine comprises a bed 10, upright standards 11
attached to said bed, and a cross web 12 connecting the upper ends of said standards.
The standards are provided on their inner faces with vertical guide-ways 13, and with
horizontal shaft-bearings 14; and the cross web is also provided with pedestals having
shaft-bearings. A driving shaft 20 is journaled in one set of bearings at the top of
the frame, and a counter shaft 30 is journaled in the horizontal bearings 14.
A plunger 35 reciprocates vertically in the guide ways 13 of the standards, and is
connected by a strap belt 31 with a pulley 32 on the driving shaft 20, said pulley being
controlled by a clutch mechanism in any suitable inanner.
The fixed die 40 is attached to the bed 10 by any suitable means, and the movable
die 41 is attached to the lower end of the plunger.
The bar from which the articles are to be forged is preferably fed to the apparatus
by a mechanical intermittent feeder. The feeder herein shown for this purpose
comprises a lateral arm 50 attached to one of the standards 11; a cam 51 on the
counter shaft 30, and provided with a cam groove 52; a lever 53 pivoted at its upper
end to said arm, and provided with a pin 54 which projects into the groove of said
cam; the lower end of said lever being adapted to grasp the bar. The bed 10 is
provided with an arm 55 carrying an anti-friction pulley 56, and a cord 57 passes over
this pulley and is connected at its upper end to a clamp 58 adjustable on the bar. The
lower end of said cord is provided with a weight 59 which tends to. feed the bar
forward when it is released by the lever 53. Any suitable bar feeder may be
employed as the equivalent of that herein described.
A blank cutter for cutting off a blank of the required size from the metal bar from
which the articles are to be made is disposed adjacent to the metal forging or working
mechanism. This blank-cutter as herein illustrated.comprises a vertically reciprocating
cutter die 60 and a fixed cutter-die 61. The fixed cutter-die 61 is supported on the
bed 10, and the movable cutter-die 60 is attached to a cross-head 62 which is
provided with guide-ways and moves on studs 68 attached to the vertical standards.
A toggle link 63 connects the upper end of the cross-head with a cam ring 64 which
encircles a cam disk 65 disposed on the counter shaft 30. This cam ring is also
connected by a toggle link 66 with a fixed rod 67 supported in lugs 67ª of the
standards. The cutting edges of the cutter-dies are preferably V-shaped. A stop 69
is disposed at one side of the cutter-dies, preferably attached to the cross-head 62.
An electric heater for heating the blank cut off from the bar to soften it for the forging
operation operates between the cutter-dies and the forging or metal working mechanism.
The electric heater herein shown for this purpose comprises two electrodes in the
form of levers 70 and 71 which are pivoted on a rod 72 supported in bracket arms 73
of suitable standards 74. These levers which serve as carriers for the blank are
composed of highly conducive material, preferably hard copper, and are insulated
from the rod on which they are pivoted by sleeves 75 of insulating material. The
outer ends of these levers are actuated by cams 76 disposed on a shaft 77 and
insulated therefrom by insulating sleeves 78. These levers are preferably provided at
their outer ends with slots 79 in which the cams 76 work. The cam shaft 77 is
provided with a pulley 80, and a belt 81 passes over said pulley and over a pulley 82
on the counter shaft 30, and motion is thereby communicated from the counter shaft
to the cam shaft. The counter shaft is provided at its opposite end with a pulley 83
which is connected by a belt 84 with a pulley 85 on driving shaft 20, whereby motion
is communicated from the driving shaft to the counter shaft. The current is supplied
to the electrodes by means of automatically adjustable contact pins 90 disposed in two
insulated guide sockets 91 on the standards 74. These contact pins are provided with
collars 92, and springs 93 are interposed between said collars and the guide sockets,
said springs acting. expansively to hold the contact pins in contact with the electrodes.
The lower ends of these contact pins are provided with binding posts 94 for connecting
the positive and negative wires therewith. The inner ends of the lever electrodes are
provided with holding faces 95 for supporting the blank cut from the bar being
worked, as indicated in dotted line in Figure 4, or in other form. Each of the
electro levers may constitute one part of a pair of clamping tongs, as illustrated in

page_text: Figure 7, for holding the blank while it is being heated. In this case the upper
member 71" of the clamping tongs is pivoted on the rod 72 and insulated therefrom,
and is controlled by a separate cam 96 and a spring 97 which act in unison with the.
cams 76 of the lower member 71 to open and close the tongs.
The levers, where they support the blank to be worked or forged, are preferably
provided with platinum faces 98 which facilitate the passage of the current from the
electrodes to the blank.
The electric circuit for passing a heating current through the metal to be worked is
illustrated in diagram in Figure 6 in which a dynamo, storage battery or other source
of electricity is represented at 100. A number of resistance coils 110 are disposed in
this circuit by means of which the volume of the current can be regulated to suit thé
requirements of the work, whereby a uniform heat may be obtained for the forging
operations.
A blank feeder, for feeding the blank cut off from the bar to the dies, may he
disposed between the electrodes and the dies. The blank feeder herein shown for this
purpose consists of an inclined table 120 disposed beneath the cutter-dies adjacent to'
the forging dies. This table is preferably hinged to an adjustable support '121 which
is dove-tailed in a recess 122 in the bed 10. An adjustable screw 123 passes through:
a plate 124 attached to the bed 10 and takes into a screw-threaded hole in the support.
When the blank is released by the electrodes it drops upon the table which tilts.
toward the dies under the weight of the blank and feeds said blank to the dies.
The operation of the apparatus is as follows: A metallic bar 200, from which the'
articles are to be forged, is fed by the bar-feeder between the cutter-dies 60 and 61
against the stop 69, and the cam disk 65 operating on the cam ring 64'straightens!
the toggle links 63 and 66 and forces down the upper die 60 whereby a blank of
the desired length is severed from the bar. This blank then drops upon the inner ends'
of the electrodes 70 and 71 which are then in the position indicated by dotted
lines in Figure 4. The blank closes the electric circuit between the electrodesí
and causes an electric current of sufficient volume to soften the blank to pass
therethrough. The inner ends of the electrodes are then swung down under the
action of the cams 76 and release the blank which falls upon the table 120 which
conducts it to the dies. The plunger 40, carrying the upper forging die is ther
brought into action and the blank forged thereby into the desired shape.
"
It will be observed that the metal to be worked is subjected to a single heat,
and the final effect of the current of electricity after the metal becomes cold is
to harden or compact the particles thereof.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. The method of forging an article from a inetal bar, which consists in cutting
off from said bar a blank of the required length for the article to be forged;
then softening said blank by passing an electric current therethrough; then with-
drawing the current; and then subjecting the blank to a forging operation, sub-
stantially as set forth.
2. In an electric metal working machine, the combination of a bar-feeder, a
bar-cutter for cutting a blank from the bar, electrodes for passing an electric
current through the blank after it is cut off, and means for delivering said blank
for the action of forging dies.
3. In an electric metal working machine, the combination of a bar-feeder, a bar-
cutter for cutting a blank from the bar, electrodes for passing an electric current
through the blank after it is cut off, and a blank-feeder for feeding said blank to the
dies after it is released by said electrodes.
4. In an electric metal working machine, the combination of a bar-feeder, a
bar-cutter for cutting a blank from the bar, electrodes for passing an electric
current through the blank after it is cut off, and a blank-feeder consisting of an.
inclined table for feeding said blank to the dies after it is released by the electrodes.

page_text: 5. In an electric metal working machine, the combination of two pivoted levers for
supporting a blank to be worked, ineans for actuating said levers, and sliding contact
pins connected with an electric circuit and engaging said levers.
6. In an electric metal working machine, the combination of two movable
carriers provided with holding faces for supporting the blank to be heated, said
carriers being connected with an electric circuit and serving as electrodes.
7. In an electric metal working machine, a heating device consisting of two
pairs of clamping tongs, electric conductors in connection therewith, and means for
opening and closing said tongs.
i
'
8. In an electric metal working machine, the combination of metal working
mechanism, and an electric heater having electrodes provided with platinum holding
faces for holding the metal to be heated.
9. In an electric metal working machine, the combination of cutter-dies, forging
dies, a feeder for feeding the metal to be worked to said forging, dies, electrodes
for heating said metal while out of contact with the dies, an electric circuit
connected with said electrodes, and a variable resistance in said circuit between
the source of electricity and said electrodes for regulating the current passed through
said metal while out of contact with the dies.
10. In an electric metal working machine, the combination of the supporting
standards 74 provided with sockets 91, the rod 72, the shaft 77 provided with
insulated cams 78, the lever electrodes 70 and 71 pivoted on said rod and insulated
therefrom, said electrodes being provided with holding faces at their inner ends
and with slots at their outer ends engaged by said cams, the spring actuated contact
pins 90, movable in said sockets, and electric connections for said pins.
11. The method of making a metal forging, which consists in forming a blank of a
determinate size for the forging to be produced; then softening said blank by passing
an electric current therethrough; then withdrawing the electric current from the
prepared blank; and then subjecting said blank to a forging operation.
DL1
1000
Witnesses:
CHESTER MARR,
Accountant,
Gloucester, Mass.
E. F. PHILIPSON,
Stenographer,
Boston, Mass.
GEORGE DEXTER BURTON.