Improvements in and relating to Electric Metal Working Apparatus.
Year: 1892

page_text: Date of Application, 17th May, 1892-Accepted, 9th July, 1892
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Metal Working Apparatus.
I, GEORGE DEXTER BURTON, a Citizen of the United States of America,
residing at 194 Washington Street, Boston, in the County of Suffolk and 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 per-
formed to be particularly described and ascertained in and by the following
statement:-
The object of this invention is to produce metal forgings of superior quality in
an economical manner, and especially to produce twisted metal bars, by the aid of
electricity, for stair rods, fence pickets, and ornamental metal work in general.
Figure 1 of the accompanying drawings represents a side elevation of this
improved apparatus in connection with an electric converter.
Figure 2 represents a plan view thereof.
Figure 3 represents a face view of the oscillating clamp for holding one end of
the bar to be 'twisted.
Figure 4 'represents a portion of a twisted bar.
Similar numerals of reference indicate corresponding parts in the different
figures.
The rings 10 and 11, whereof segments only are represented in the drawings,
constitute parts of an electric current converter, which need not be fully illustrated
in this case. The ring 10 is provided with a boss 12, and the ring 11 with a boss 13,
which bosses constitute the terminals of the converter.
A bracket 20, composed of copper or other suitable conductive material, is
attached at one end to the boss of the ring 10 and depends therefrom when
arranged as 'shown in the drawings.
A similar bracket 30, also composed of copper or other suitable conductive
material, is attached to the boss or terminal 13 of the converter ring 11 and
depends therefrom:
The outer ends of these brackets are provided with arms 21 and 31 respectively,
which are preferably slotted longitudinally and adjusted in line with each other
in the same horizontal, plane. The brackets and arms may be composed wholly
or in part of iron or other material or composition of lower conductivity than
copper, provided they be sufficiently large in proportion to the bars to be operated
upon to carry a current adapted to heat such bars to a forging temperature without
becoming overheated themselves.
Two clamps 40 and 50, composed of copper, iron or other suitable conductive
material, are adjustable respectively on the arms 21 and 31. These clamps or.
holders may be of any suitable construction for clamping the ends of the bar to
be heated and twisted.
A
A bar twisting apparatus is disposed on the arm 31. This bar twister com-
prises two similar adjustable standards 60 and 61, a shaft 70 journaled in
said standards, and a clamp 71 at one end of said shaft for grasping one
end of the bar to be twisted. A third standard 62, somewhat taller than the
shaft-supporting standards, is disposed at the outer end of said arm 31.
stub shaft 80 is journaled in said standard 62 and provided at one end with a
beveled pinion 81 and at the other end with an actuating crank 82. The outer
end of the shaft 70 is provided with a beveled gear 72 which meshes with the
pinion 81'on the stub shaft 80.
The clamp 71"comprises a rectangular frame 73, two sliding jaws 74 and 75, and

page_text: set screws 76 and 77 passing through the ends of said frame and engaging said
jaws for adjusting them upon the end of the bar.
The standards 60, 61 and 62 are severally provided with lugs 63 which
project downward through the slot in the arm 31, and said arm is provided at its
outer end with a fixed dependent lug 64 having an insulating bushing 65. A screw
rod 66 passes through the bushing 63 and through the lugs 63 and is provided
with a hand wheel 67 at its outer end. This screw rod serves to adjust the twister
on the arm 31.
In the use of this apparatus one end of a metal bar 100 to be twisted is placed
in the clamp 40 and the other end in the clamp 50, said bar extending through
the clamp 50 and the extended end thereof being engaged by the jaws of the
clamp 71. Both the clamps 40 and 50 are closed tightly upon the bar and the
electric current switched on. The current passes from the positive ring 10 of the
converter through the bracket 20, or other conductor, leading from said ring,
thence through the arm 21, thence through the clamp 40, thence through the bar 100
to be heated to the clamp 50, thence through the arm 31 to the bracket 30 and
through said bracket or its equivalent to the negative ring 11 of the converter.
The rod 100 under the action of the heating current will be heated in a few
seconds to a forging temperature throughout that portion of its length which spans
the space between the clamps 40 and 50; while the ends which are directly in
contact with the clamps will remain cool in the metallurgical sense of the term.
The current is then switched off and the clamp 50 released from the bar. The
crank 82 is then turned whereby the shaft 70 and its clamp 71 are rotated. One
end of the bar 100 being still held in the clamp 40 and the other end in the
clamp 71. The rotation of the shaft 70 causes a twisting of the bar, as repre-
sented in Figures 1, 2 and 4. The bar may be twisted more or less as desired, and
is then released from the clamps and removed from the apparatus.
In the use of the electric current for heating bars or blauks, I have found that
the bar or blank is heated from the interior instead of the exterior as in the
ordinary furnace forge, and that there are no gases introduced into the metal when
heated by electricity and consequently when twisted no scale is formed, and the
metal is left clean and free from blemishes. Moreover, the bar retains the heat
developed by the electric current from its interior longer than the surface heat
of the ordinary forge. When heated from the exterior the outer surface of
the metal is broken, which causes the scale, owing to the fact that the exterior
is overheated before the interior is heated to the required working temperature.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed 1 declare that what
I claim is :-
1. In an electric metal working apparatus, the combination of two converter
rings constituting the positive and negative poles, two conductive brackets con-
nected respectively to said rings and provided with horizontal arms, two clamps
adjustable toward and from each other on said arms, two standards on one of said
arms, a shaft journaled in said standards and provided with a clamp at one end,
and means for rotating said shaft.
2. In an electric metal working apparatus, the combination of two converter
rings constituting the positive and negative poles, two conductive brackets
connected respectively to said rings and provided with horizontal arms, two
clamps adjustable towards and from each other on said arms, two standards on
one of said arms, a shaft journaled in said standards and provided with a clamp
at one end, means for rotating said shaft, and means for adjusting said standards
on said arm.
3. In an electric metal working apparatus, the combination of two converter
rings constituting opposite electric poles, two conductive arms or beds connected
respectively with said rings, a bar holder or clamp disposed on one of said arms,

page_text: a bar holder or clamp disposed on the other arm, and a bar twister also disposed on
one of said arms and adapted to engage one end of the bar to be twisted.
Dated this 5th day of April 1892.
GEORGE DEXTER BURTON.
Witnesses:
ETTIE F. PHILIPSON,
Stenographer, Boston, Mass., U.S.A.
FRED J. HUTCHINSON.
Attorney-at-Law, 209, Washington Street, Boston, Mass., U.S.A.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.