An Improved Method of and Apparatus for Heating Metal Bars or Blanks by Electricity for Forging and other Purposes.
Year: 1891

page_text: Date of Application, 23rd June, 1891-Accept.d, 25th July, 1891
COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Heating Metal Bars or
Blanks by Electricity for Forging and other Purposes.
I, EDWIN ELLIOTT ANGELL, of Somerville, in the County of Middlesex and
State of Massachusetts, United States of America, Machinist, 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 methods of and apparatus for heating metal bars or
blanks for the manufacture of forgings and other purposes.
The object of this invention is to heat a succession of metallic bars or blanks in
an economical manner.
The invention consists in the method of heating metallic bars or blanks by
inserting a bar or blank in an electric circuit, then inserting another bar or blank
in shunt in the same circuit, and then withdrawing one of said bars or blanks from
said circuit, the other bar or blank remaining in circuit during such withdrawal.
The invention consists further in the apparatus hereinafter described and claimed
in which this method may be carried out.
Figure of the accompanying drawings represents a longitudinal vertical
section of this improved electric heater.
Figure 2 represents a longitudinal horizontal section thereof on line 22 of
Figure 1.
Figure 3 represents an elevation of the rear end thereof.
Figure 4 represents a perspective view of the conductive contact piece of one of
the split electrode jaws, and the short conducting rod for conveying the current.
thereto, the split end of the jaw, the end of one of the auxiliary lever electrodes,
and the conducting contact roller journalled therein, being indicated in dotted
lines.
Figure 5 represents a vertical section taken longitudinally of the upper
transverse shaft between the supporting frame, showing the bushings and adjustable
collars thereon, and the upper main and auxiliary electrode levers.
Figure 6 represents a top plan of the upper, or a bottom plan of one of the
lower auxiliary lever clectrodes.
Figure 7 represents a side elevation thereof.
Figure 8 represents an end elevation thereof.
Figure 9 represents a plan of the inner face of one of the main lever electrodes.
Figure 10 represents a side elevation thereof.
Figure 11 represents an elevation of the jaw end thereof.
Figure 12 represents a plan and side view of the conductive contact piece of one
of the split jaws.
Figure 13 represents side and end views of the conducting roller of one of the
auxiliary electrode levers.
Figure 14 represents the conducting cables for the electric current so connected
with the apparatus as to pass currents longitudinally of the bar or link to be
heated.
Figure 15 represents the conducting cables so connected with the apparatus as
to pass currents transversely through the blank to be heated.
Figure 16 represents the conducting cables adjusted so as to pass a current
diagonally through the blank to be heated.
Similar numerals of reference indicate corresponding parts in the different
figures.
The support for this electric heater may consist of a rectangular frame or
bracket 10 adapted for attachment to a wall or to a forging machine. The

page_text: rectangular frame shown in the drawings comprises an attaching plate 11,
dependent arms 12 and 13, which curve outwardly from said plate and then
extend vertically downward, a cross-bar 14 connecting said dependent arms at the
upper ends of their straight portions and a cross-bar 15 connecting said arms at
their lower ends.
The cross-bars 14 and 15 are provided with dovetail guide grooves 16, and
with set-screws 17 opposite said grooves. Two adjustable arms extend hori-
zontally and longitudinally of the machine from the upper cross-bar 14. One of
these arms on the rear side is numbered 21 in the drawings and the other, which is
correspondingly disposed on the front side and which is hereinafter referred to as
arm 20, does not appear in the views represented in the drawing. These arms
are provided with T-heads having dovetail tongues 24 fitting the dovetail
grooves of said cross-bar and two similar adjustable arms 22 and 23 are secured in
a similar manner to the lower cross-bar 15, being adjustable therein by means of
set-screws 17. Each of the upper adjustable arins 20 and 21 is provided near its
outer end with an elongated dependent tubular lug 26, and near its inner end with
a short dependent tubular lug 27, and the lower adjustable arms 22 and 23 are
provided near their outer ends with elongated upright tubular lugs 28, and near
their inner ends with short upright tubular lugs 29. Adjustable stops 30,
composed of insulating material, are severally disposed in these tubular lugs, and
rendered adjustable therein by means of adjusting screws 31.
Two transverse shafts or rods 40 and 41 are disposed, one above the other, in
the frame 10. These shafts are provided at their outer ends outside the frame
with collars 42.
Two electrode levers 50 and 51 are pivoted on the lower shaft 40 and two
similar electrode levers 60 and 61 are pivoted on the upper shaft 41. These four
electrode levers are all provided with short, hollow trunnions 52, through which
the shafts pass, said trunnions having flanged bushings 53 composed of insulating
material, and the trunnions on the same shaft being separated from each other by
ring bushings 54. Steel sleeves 55 serve as linings for the bushings to prevent
wear thereof. Adjustable collars 56 are disposed on the shafts outside the
trunnions, and insulated therefrom by the flanges of the flanged bushings 53.
These collars may be adjusted on the shaft by means of set screws 57.
The main electrode levers 50, 51, 60 and 61, are of similar construction, and are
provided with longitudinal vertical slots 58 opposite their trunnions. The lower
lever electrodes 50 and 51 are provided at their rear ends with upwardly projecting
horizontally elongated split jaws 59, having tightening screws 62, and the upper lever
electrodes 60 and 61, are provided at their rear ends with downwardly projecting
horizontally elongated clamping jaws 63, provided also with tightening screws 62.
These jaws are provided with conductive contact pieces 64 composed of metal of
high conductive power, having a high fusing point. These contact pieces are
clamped in the split jaws and are provided at their inner ends with contact
boxes 65, and with lugs 66 in line with their contact faces.
Contractile springs 68 connect the front ends of these lever electrodes with the
adjustable arms 20, 21 22 and 23, and tend to close the jaws thereof toward each
other. This movement of the levers is regulated by the adjustable stops 30 of
the short lugs 27 and 29 on said arms.
Two auxiliary lever electrodes 70 and 71 are also pivoted on the lower shaft 40
and two similar auxiliary lever electrodes 80 and 81 are pivoted on the upper
shaft 41. These auxiliary levers are provided with perforated pivot ears 72
through which the shafts pass and which fit into slots 58 of the main lever
electrodes. The rear ends of these levers terminate at points opposite the inner
ends of the jaws on the main levers, and are provided at said ends with inwardly
projecting perforated lugs 73 and 74. At their opposite ends they are provided
with perforated lugs 75 having insulated bushings and opposite their pivots they
are provided with perforated similarly bushed lugs 76. Conducting rods 77 of
copper or other suitable material extend parallel with the lever electrodes, and are

page_text: supported in the lugs 75 and 76 thereof. Shorter conducting rods 78 arc
supported in the lugs 73 and 74 and are connected with the rods 77 by means of
connecting sleeves 79 provided with set screws 82. Contact rollers 83, composed
of conducting, comparatively non-fusible material, are disposed on the rods 78
between the lugs 73 and 74, and serve the triple purpose of feed rolls, clamping
jaws, and electric conductors. The outer ends of the conducting rods 78 enter the
boxed ends of the conductive contact pieces 64 at the inner ends of the jaws of
the main levers. Springs 84 connect the auxiliary levers with the outer ends of
the adjustable arms, and tend to move the upper and lower auxiliary levers toward
cach other, this movement being regulated by the adjustable stops of the
elongated lugs of said arins. The lugs 65 of the conducting contact pieces,
bridge the spaces between the contact faces of the jaws of the main and the
auxiliary electrode levers.
The outer ends of the conducting rods 77 are provided with clamping sleeves 90
having set screws 91 and 92 for connecting the branches of the cables with
the rods.
The positive cable 100 is provided with branches 101 and 102 which may be
connected with the rods of the two upper auxiliary electrodes. A negative
cable 110, connected with a dynamo or current transformer is provided with
branches 111 and 112 which may be connected with the conducting rods of the
lower lever electrodes, as shown in Figure 3.
In carrying out this method by this apparatus, a bar, as 200, to be heated and
softened for a forging operation or for other purpose, is passed endwise between
the pair of roller jaws of the upper and lower auxiliary electrode levers 70 and 80
at one side of the heater and across to and between the pair of jaws 71 and 81, at
the other side of the heater, spanning the space between said pairs. When the
conducting cables are connected as shown in Figures 2 and 15, two currents are
passed transversely through the bar one from the electrode 80 to the electrode 70
and another from the clectrode 81 to the electrode 71. When the cables are
connected as shown in Figure 14, two currents are passed longitudinally of the
bar, one from the electrode 70 to the electrode 71 and another from the electrode 80
to the electrode 81. The electrodes may be so adjusted on the shafts as to increase
or diminish the distance between the two pairs of jaws, but when transverse currents
are passed through the bar, the distance between the pairs of jaws should not greatly
exceed the diameter of the bar to be heated. In that case the part between the
jaws is heated by conduction. The bar or blank is then moved outward between
the conductive contact pieces 64 of the jaws 59 and another bar, as 300, is inserted
between the jaws of the auxiliary electrodes. These jaws yield independently of
the main electrodes to permit the insertion of the bar and the rods 78 play in and
remain in contact with the contact boxes 65 of the conducting pieces 64, whereby
the current is maintained through the main jaws during the insertion of a bar or
blank, between the auxiliary jaws. After the insertion of the bar 300 between the
jaws of the auxiliary electrodes, the bar 200 can be removed from between the jaws
of the main electrodes without breaking the main electric circuit which continues
through the bar 300. The bar 300 is then moved outward and another bar inserted,
and the operation may thus be continued indefinitely without breaking the current.
Two or more bars or blanks may be held at the same time between the jaws of the
main levers.
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 heating metallic bars or blanks which consists in inserting a
bar or blank in an electric circuit, then inserting another bar or blank in shunt
in the same circuit, then withdrawing one of said bars or blanks from said circuit,
the other bar or blank remaining in circuit during such withdrawal, substantially as
described.

page_text: 2. In an electric heater, the combination of two pairs of electrode-levers disposed
apart from each other and having elongated clamping jaws adapted to receive two
or more bars or blanks, substantially as described.
3. In an electric heater, the combination of a supporting frame, two pairs
of lever-electrodes pivoted therein, and provided with clamping jaws, and
arms extending froni said frame and provided with insulated stops for said
electrodes.
4. In an electric heater, the combination of a supporting frame, two pairs of
lever-electrodes pivoted therein and provided with clamping jaws, arms extending
from said frame and provided with insulated stops for said electrodes, and springs
connecting said electrodes with said arms.
5. In an electric heater, the combination of a supporting frame, two shafts disposed
in said frame, one above the other, two lever electrodes pivoted on the upper shaft
and adjustable toward or from each other, and two lever electrodes pivoted on the
lower shaft and adjustable thereon.
6. In an electric heater, the combination of a pair of pivoted electrode levers
provided with clamping jaws, and a pair of pivoted auxiliary electrode levers having
clamping jaws disposed in line with the clamping jaws of the main levers, and
adapted to open and close independently thereof.
7. In an electric heater, the combination of a pair of pivoted electrode levers
provided with clamping jaws, and a pair of pivoted auxiliary electrode levers having
clamping jaws disposed in line with the clamping jaws of the main levers, and adapted
to open and close independently thereof, the clamping jaws of the auxiliary levers
being provided with conductive feed rollers.
:
8. In an electric heater, the combination of a supporting frame, two shafts therein,
horizontal arms adjustable on said frame, electrode levers adjustable on said shafts,
springs connecting said arms with said levers, and adjustable stops on said arms for
regulating the movements of the electrode levers.
.
9. In an electric heater, the combination of a frame, two shafts supported
therein, two main levers provided with hollow trunnions through which said
shafts pass, and with longitudinal slots traversing said trunnions, and auxiliary
electrode levers provided with perforated pivot ears hung on said shafts within
said slots.
10. In an electric heater, the combination of two pairs of electrode levers disposed
apart from each other and provided with electro-conductive clamping jaws, and two
pairs of auxiliary electrode levers provided with conductive clamping jaws in line
with the jaws of the main electrode levers.
11. In an electric heater, the combination of a pair of electrode levers having jaws
provided with conductive contact pieces, a pair of auxiliary electrode levers provided
with conductive jaws and with perforated lugs, conductive rods disposed in said lugs,
and insulated therefrom, the rear ends of the rods being in contact with the
contact pieces of the main jaws.
01
1
1001
EDWIN ELLIOTT ANGELL.
Witnesses:
F. C. SOMES, Lawyer,
514, F Street, N.W., Washington, D.C., U.S.A.
EDWARD NEWITT, Machinist,
Fitchburg, Mass.
Haseltine Lake & Co