Improvements in Electric Blank Heaters for Forging Machines.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Blank Heaters for Forging Machines.
We, GEORGE DEXTER BURTON, a Citizen of the United States of America,
residing at Boston, in the County, of Suffolk and State of Massachusetts, United
States of America, Inventor and Car Builder, and EDWIN ELLIOTT ANGELL, a
Citizen of the United States of America, residing at Somerville, in the County of
Middlesex and State of Massachusetts, United States of America, Machinist, do
hereby declare the nature of our invention, for IMPROVEMENTS IN ELECTRIC
BLANK HEATERS FOR FORGING MACHINES, 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 an electric heater for use in connection with a forging
machine for heating to a forging temperature blanks for the manufacture of
forgings.
The object of the invention is to provide a simple and effective apparatus for
this purpose in which the electrodes and their co-operative parts are adjustable to
suit blanks of different lengths for the manufacture of forgings of different sizes; in
which said electrodes are adapted to automatically grasp and release the blanks
with facility; and in which said electrodes are under the control of the operator
for determining the heating periods.
Figure of the accompanying drawings represents a side elevation of this
improved electric blank heater.
Figure 2 represents a plan thereof.
Figure 3 represents a rear elevation thereof, a portion of the back plate being
broken out.
Figure 4 represents a vertical longitudinal section on line 4-4 of Figure 2.
Figure 5 represents a detailed view of the cam sleeve for controlling the
electrodes.
Figure 6 represents a detailed view of an adjustable pivot for one of the
electrodes.
Similar numerals of reference indicate corresponding parts in the different
figures.
The frame of this electric heater comprises two standards 10, a base plate 11,
and a back plate 12, all of which may be cast in one piece. These standards are
provided near their upper ends with short brackets 13, having vertical front
faces 14.
A driving shaft 20 has its bearings in the brackets 13 of the standards, and a
counter shaft 30 has a bearing at one end in the upper end of one of the standards,
being supported at the other end in a sleeve hereinafter described which has a
bearing in the opposite standard. The driving shaft 20 is provided with a driving
pulley 21, and with a pinion 22, which meshes with a gear wheel 31 on the counter
shaft.
An oscillating guide-way 40 is supported between the standards on the driving
shaft 20. This guide-way is provided with a longitudinal guide groove 41. Two
adjustable pivot blocks 42 are disposed on said guide-way, said blocks being provided
with guides 43, which engage said groove. Each of these blocks is also provided
with a horizontal socket 44, and with a slot 45 along its top opening into said socket.
Pivot pins 46 are disposed in said blocks. Each of these pivot pins is provided at
its lower end with a cylindrical foot 47 at right angles to its body, and at its upper
end with a screw-threaded tang 48. The cylindrical foot fits in the horizontal
socket 44, and the body of the pin plays in the slot in said block. The outer end
of said socket is closed by a screw 49 and a spiral spring 50 is disposed in said

page_text: socket between said "screw and the pivot pin. A sleeve 33 is disposed on the
shaft 30 and extends through one of the standards 10. This sleeve is provided with
a feather 34. A clutch mechanism, one member of which is rigidly attached to the
shaft, and the other to the sleeve, serves to connect the sleeve with the shaft, and
disconnect it therefrom.
The clutch comprises a disk 32 fixed to the shaft 30 and a disk 33' fixed to the
sleeve 33. The disk 32 is provided with slots 37 at diametrically opposite points
and the disk 33' is provided with slots 36 also at diametrically opposite points in
which are disposed the sliding dogs 34'. These dogs are normally forced outward
by the springs 35 and are adapted to engage the slots 37 in the disk 32 for locking
the disks together. The dogs are provided with recesses at their rear ends which
are engaged by the lever 38 on the upper side of the shaft and by the cam 39
attached to the frame on the under side of the shaft. The disks are clutched and
unclutched by means of the lever 38 which controls the dogs. The cam 39 prevents
the engagement of the dogs at the lower side of the shaft and the plurality of slots
permits one or more stops to each revolution. This clutch is the same as that used
on ordinary punch presses which effect stops during a revolution.
These eccentrics
Two eccentrics 60 provided with peripheral cam grooves 61 are disposed on the
sleeve 33, being locked against rotation thereon by the feather 34.
are adjustable on said sleeve by means of set screws 62.
These levers are
Two levers 70 are pivoted on the adjustable pivot pins 46.
provided with vertical forks 71 at their rear ends which engage the peripheral faces
of the eccentrics 60 for imparting a vertical oscillation to said levers, and the upper
arms of these forks are provided with pins 72 carrying friction rollers 73 which
project into the cam grooves 61, for imparting a lateral oscillation to said levers.
Any equivalent horizontal oscillator or vertical oscillator may be employed in lieu
of the oscillating mechanism above described for imparting vertical and horizontal
oscillations to the electrodes. The front ends of these levers are provided with
angular arms 74 having insulated faces 75.
Two electrodes 80 composed of copper or other highly conductive material, are
supported at their rear ends on said insulated arms. These electrodes extend
parallel with each other when in normal position, and are provided near their front
ends with recesses 81 cut into their upper and inner faces, said electrodes serving to
support the blank 200 to be heated, the opposite ends of said blank resting in said
recesses.
The electrodes are clamped at their rear ends to the insulated arms 74 by means
of bolts 82 which pass vertically through said electrodes, and through said arms,
being insulated from the latter. These bolts are provided with binding posts 83 at
their upper ends to which the wiges or cables 100 of the electric circuit are attached.
These bolts serve as conductors for the electric current, and their lower ends rest
upon vertically movable contact pins 84 which pass through sockets 85. These
sockets are laterally adjustable in a transverse guide-way 86 extending between the
standards. Sleeves 87 serve to insulate said pins from their sockets. These pins
are provided with heads 88 at their upper ends, and the insulating sleeves with
flanges 89 below said heads. Springs 90 are interposed between the upper ends of
the sockets and said flanges, and tend to hold said pins in contact with the bolts 82
of the electrodes. The contact pins are screw-threaded at their lower ends and
provided with binding posts 91. A rheostat 92 is connected by wires or cables 93
with the binding posts 91 attached to the lower ends of the contact pins. A lever
frame 94 is pivoted to opposite sides of the frame at 95, and connected with the
binding post of one of the sliding contact pins by means of a link 96. This frame
is provided with a foot lever 97 by the depression of which one of the contact
pins 84 is withdrawn from its bolt 82, and the circuit is broken.
Feeders for feeding the blanks from the electrodes to the forging dies (not shown
in the drawings) are attached to the heater. The feeders herein shown comprise
two bent strippers; each consisting of an approximately vertical arm 111 and an
approximately horizontal arm 112. These strippers are attached at the lower ends

page_text: of their vertical arms by bolts 113 to the vertical sockets 85 of the sliding contact
pins, and are insulated from said sockets. The upper approximately horizontal
arms of these strippers are disposed parallel with each other in vertical planes
passing between the electrodes, and serve to release the blank from the electrodes
as the electrodes are depressed, and as inclined planes to contact said blank to the
forging dies.
The operation of the apparatus is as follows: The parts being in the position
illustrated in Figure 1, a blank 200 is disposed between the electrodes, its ends
resting in the recesses 81. The blank serves as a conductor for closing the circuit
between the electrodes, one of which is positive and the other negative. This
closing of the circuit causes a current of large volume to pass through the blank,
the resistance of which is greater than that of the electrodes and heat sufficient to
soften the blank is quickly generated. The driving shaft 20 revolving in the
direction of the arrow 150, causes the gear wheel 31 to revolve in the direction of
the arrow 160, and the parts of the clutch 32 being in gear, the sleeve 33 and its
eccentric grooved cams 60 are rotated. The cam grooves 61 therein impart a
horizontal oscillation to the levers 70 on their pivots 46 and cause the electrodes to
move apart from each other sufficiently to release the pressure thereof upon the
ends of the blank and at the same time the peripheral action of the cams raises the
outer ends of the levers 70 and depresses the electrodes below the plane of the stripper
arms 112, whereby the blank 200 is deposited on said arms. The blank then rolls
down these inclined arms to the forging dies.
As the sleeve 33 continues to revolve, the electrodes are raised and another blank
is fed thereto in any suitable manner or by any suitable means, and deposited with
its ends resting in the recesses 81. The cam grooves then swing the electrodes
toward each other and bring the sides or flanges of the recesses into contact with
the ends of the blank so that the extreme ends thereof will receive the heating
current.
The adjustable spring-pressed pivot-pins 46 of the levers 70 cause a yielding
contact of the electrodes with the blank and permit said electrodes to adjust them-
selves to blanks for the same purpose which may vary somewhat in length. When
it is desired to change the length of the blanks for different sized forgings the
levers 70 carrying the electrodes 80 are adjusted toward or from each other by the
adjustment of the pivot blocks 42 on the oscillating guide-way 40. The eccentric
cams 60 are correspondingly adjusted on the sleeve 33 and the contact pins 84 are
also adjusted to suit the changed position of the electrodes by the adjustment of the
sockets 85 on the guide-way 86. This adjustment of the sockets also adjusts the
strippers when the latter are attached to the sockets as shown, but adjustment of
the strippers is not necessary to the proper working of the apparatus.
By means of the lever 38, the parts of the clutch 32 may be unclutched and the
motion of the sleeve arrested whereby the blank may be held in the electrodes for
any desired length of time.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
1. In an electric blank-heater, the combination of two electrodes adapted for
holding a blank to be heated, and vertical and horizontal oscillators for imparting
vertical and horizontal oscillation to said electrodes.
2. In an electric blank-heater, the combination of two levers carrying electrodes
adapted for holding a blank to be heated, a guide-way, and pivot blocks adjustable
in said guide-way and provided with pivot pins for said levers.
3. In an electric blank-heater, the combination of pivot blocks, pivot pins adapted
to slide in said blocks, springs for affording an elastic adjustment of said pivot pins,
and electrode levers fulcrumed on said pivot pins.
4. In an electric blank-heater, the combination of two pivoted levers provided
with electrodes adapted for holding a blank to be heated, oscillating supports for

page_text: the pivots of the levers, eccentric disks provided with peripheral cam grooves
engaging said levers for imparting vertical and horizontal oscillations thereto.
5. In an electric blank-heater, the combination of a frame, an oscillating guide-
way disposed therein, pivot blocks adjustable on said guide-way, pivot pins disposed
in said blocks, levers fulcrumed on said pivot pins, and provided with forks at their
rear ends, and electrodes at their front ends, and eccentric cams.
grooves engaging said levers.
provided with
6. In an electric blank-heater, the combination of an oscillating guide-way, pivot
blocks adjustable in said guide-way and provided with pivot pins, and levers
fulcrumed on said pivot pins.
7. In an electric blank-heater, the combinatian of two levers carrying electrodes
adapted for holding a blank to be heated and provided with forked ends having
pins, eccentric cams engaging said forked ends, and provided with cam grooves
engaged by said pins.
8. In an electric blank-heater, the combination of two levers carrying at one end
electrodes adapted for holding a blank to be heated, and provided with forked
extensions at their opposite ends, adjustable pivots for said levers, a feathered
sleeve, and cams adjustable on said sleeve engaging the forked ends of said levers.
9. In an electric blank-heater, the combination of two levers carrying at one end
electrodes adapted for holding a blank to be heated, and provided with forked
extensions at their opposite ends, adjustable pivots for said levers, a feathered
sleeve, cams adjustable on said sleeve engaging the forked ends of said levers and
adjustable contact pins for the electrodes."
10. In an electric blank-heater, the combination of two levers carrying at one
end electrodes adapted for holding a blank to be heated, and provided with forked
extensions at their opposite ends, adjustable pivots for said levers, a feathered
sleeve, cams adjustable on said sleeve engaging the forked ends of said levers,
adjustable contact pins for the electrodes, a shaft within said sleeve, a lutch
mechanism for connecting said sleeve and shaft, and a lever for unclutch g the
clutch mechanism and arresting the motion of the sleeve.
11. In an electric blank-heater, the combination of the lever 70 havg the
arms 74, the electrodes 80 disposed on said arms and insulated therefrom, the
bolts 82 clamping said electrodes to said arms, and provided with binding pat
their upper ends, and spring contact pins 84 for contact with said bolts.
12. In an electric blank-heater, the combination of a guide-way 86, the sock ts 8.
adjustable therein, and the spring contact pins 84 supported in said sockets.
A
13. In an electric bank-heater, the combination of the sockets 85, spring co tact
pins 84 disposed therein, and a foot lever connected with one of said contact pins
for depressing it to break the contact.
14. In an electric blank-heater, the combination of two electrodes adapte or
holding a blank to be heated, strippers disposed in vertical planes passing bet .en
said electrodes, and means for depressing said electrodes below the strippers.
Dated this 6th day of January 1891.
Witnesses,
CHESTER MARR,
Accountant, Boston, Mass.
E. F. PHILIPSON,
Stenographer, Boston, Mass.
GEO. D. BURTON.
EDWIN E. ANGELL.