Improvements in Methods of and Apparatus for Utilizing Electricity in the Formation of Sheet-metal Articles.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in Methods of and Apparatus for Utilizing Electricity
in the Formation of Sheet-metal Articles.
I, MARK WESLEY DEWEY, of the City of Syracuse, in the County of Onondaga, in
the State of New York, United States of America, Electrician, do hereby declare the
nature of my invention for IMPROVEMENTS IN METHOD OF AND APPARATUS FOR
UTILIZING ELECTRICITY IN THE FORMATION OF SHEET-METAL ARTICLES, and in what
manner the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
My invention relates to certain processes of and apparatuses for use in my process
of forining sheet-metal articles, which requires the employment of heat to soften or
anneal the metal, and the application of pressure to gradually conform the sheet to the
surface of a suitable die or mould.
Articles have been manufactured from sheet metal heretofore by successive and
graduated pressings depending on the depth of the article, and in some cases the metal
was annealed after each pressing, as such pressing operation rapidly hardened it,
which in turn caused the metal to tear and crack. Some metals, as German silver,
are too brittle to be pressed to a great extent by this method. The process depends
for its success upon the malleability of the metal, and it is the purpose of my invention
to keep the metal annealed or in a softened condition during a greater part of, if not
the entire or complete formation of the article, and to decrease the number of moulds
as well as the number of pressings usually required in forming or shaping the article,
and also to save time and handling.
The object of my invention also, is to provide a process or method that will produce
more durable and superior sheel-metal ware, allow the formation of articles from
thicker sheet metal, and from various metals heretofore incapable of being pressed.
My invention consists essentially in electrically heating the metal sheet, preferably
by passing an electric current through the same before and while said sheet is formed
over or within a die or mould by pressure, gradually and suitably applied, as
hereinafter described.
My invention consists also in certain improved processes involving the application
of a heating current of electricity to the formation of sheet-metal hollow-ware, cartridge
cases, etc., and also in certain apparatuses and devices useful in practising the method
or process described and claimed herein.
In the accompanying drawings,
Figure 1 is a side and edge view of a disk of sheet metal to be operated upon,
Fig. 2 shows a side elevation of a lathe for holding the disk of sheet metal upon a
mould and rotating the same while pressure is applied with an instrument to form said
disk to the shape of the mould,
Fig. 3 shows a sheet metal article partly formed over the same mould,
Fig. 4 represents the article completed,
Figs. 5, 6, 7 and 8 are sectional views of a number of different shaped articles that
be formed by my process and apparatus,
may
Fig. 9 is an elevation of an apparatus for effecting my method of forming sheet-
metal articles by stamping or drawing, and is a view taken before the operation upon
the sheet,
Fig. 10 shows the same apparatus after the operation upon the sheet,
Fig. 11 is a plan view of a portion of the apparatus taken below the dotted liner, c
in Figure 9,
Fig. 12 is a sectional view of the article after it is pressed,
Fig. 13 represents a modified form of making electric contact with the sheet while
in position.

page_text: Figure 14 shows several views of a metallic cartridge case formed by my method,—
onc view shows the case in perspective after it is formed, but prior to the heading
operation, another view shows the same after the heading operation, and another is a
sectional view, and
Fig. 15 represents a simple cartridge case heading machine that may be employed in
carrying out my method.
Referring specifically to the drawings, A in Fig. 2 is a sheet of thin metal,
preferably in the form of a disk as shown in Figure 1, mounted upon a lathe B and
held by pressure from a head-stock a against a mould of the required form, fixed on
the face-plate a of the revolving spindle. The metal sheet may be cut into the form
of a disk in any suitable manner either before or after said sheet is placed in position
upon the mould in the lathe. The disk is preferably heated by passing a heating
current of electricity through the same from a point at or near its centre, or where the
head-stock a bears against it, to the point where the pressure instrument or burnisher D
is in contact with it.
The pressure instrument D may be of metal or some suitable non-conducting
material. When said instrument is metallic the current may be circulated through
the apparatus as shown, from the conductor & through the back-head c, spindle and
head-stock a to the sheet A, through said sheet to the point where the instrument D is
pressed against it, and through the instrument to and through the flexible conductor b¹
connected therewith, back to a suitable source of electricity to which both conductors b
and are connected.
When the instrument D is of non-conducting material as bone or wood, or even
when metallic, the current may be passed through an adjustable contact or brush E
bearing upon the disk as shown in dotted lines in the figure. Said contact may bo
adjusted and moved to any desired position to make and maintain contact with the
disk while it is rotated and formed into an article. The conductor 6' is then connected
to the contact E instead of the instrument D. Instead of passing the current through
the lathe spindle another contact attached to the conductor may be provided to bear
upon the disk. The pressure instrument D is held upon the lathe-rest d as a fulcrum
and while the disk A and mould C is revolved said instrument is applied to the disk
near the centre and rapidly bent or swaged, so as to fit close against the curved face
of the mould. The instrument D may be held and moved by any suitable means, but
preferably in the hand and by the handle . A gentle pressure is caused to bear on
one point thus producing a slight depression, but as the sheet is spinning at high
velocity, the depression at once forms a circle, and so, by continuing the pressure
of the instrument and gradually moving the same, the sheet is moulded into any form
accordingly.
The mould C is preferably made of non-conducting material or of conducting
material coated with a non-electric conducting material, as a mineral paint or enamel.
Various forms of pressure instruments or burnishers may be used--the one shown in
Figure 3 being provided with a roll to decrease the friction between the bearing
points. Sectional moulds are employed when the form of the article as shown in
Fig. 6 will not permit the removal of a solid mould after the article is formed or spun
over the mould,"
Referring now to Figures 9, 10 and 11 of the drawings, represents an ordinary
screw stamping press in different positions and having a number of improvements for
carrying out my process or method by stamping or drawing. Two moulds or dies
are employed in this apparatus at a time. The hollow mould C is placed on the bed
or base and upon it is laid a blank of sheet metal A or a pile of blanks when several
are to be stamped at once. The underside of the blank or sheet A rests upon the flat
upper surface of the lollow die. When the upper die or mould C descends (which
die fits quite closely into the lower hollow die or mould when at its lowest position)
yielding clamps 11 and H carried upon the follower or plunger to which the upper
die is secured, descend with it, and firmly press the sheet A at points on each side of
the dies against electric terminals I and I connected to the conductors and to
make good electric contact between the same and the sheet. The electric current is

page_text: thus permitted to flow through the sheet A between the terminals, the sheet becomes
heated and softened or annealed and is expanded into the hollow die, siretching out
into a smooth seamless pan or other article without buckling or corrugating.
These yielding clamps Hand H¹ serve as holders for the sheet A and may be
located on all sides of the dies if desired. Said clamps may be faced with non-electric
conducting material where they come in contact with the sheet, or the cars e supporting
said clamps may be insulated from the plunger by insulation e' to prevent short-
circuiting of the current through the plunger.
The base of the press is insulated from the terminals by insulation ii, to prevent
the current short-circuiting through the base.
I do not limit myself to the form of holders or clamps as any suitably formed and
insulated holders may be used, another form of which is shown in Figure 13 of the
drawings. This clamp H is fixed to, but insulated from the base by insulation i¹
and is directly connected with the conductor 6'. The pivoted jaws of the clamp
firmly grip the edge of the sheet A by means of the screw and the said sheet is not
only held to make good electric contact, but to keep the same smooth while it is
pressed or formed.
The moulds or dies for my stamping apparatus are also preferably formed entirely
of or faced with a suitable non-electric conducting material to prevent the current
short-circuiting through them. The dies C and C shown in Figs. 9 and 10 cut the
article just before it is completely formed from the sheet by means of the annular
knife n, but this is not essential as it may not be cut until after it is entirely completed
or removed from the dies.
In Figure 12 the article is shown in section as it appears after it is removed from
the dios.
I do not limit myself to forming completely an article by a single impression as it
may be necessary or desirable to make several impressions upon the article before it is
completed.
In forming a cartridge case by my method, for instance, I preferably first form the
case without a head as shown at 1 in Fig. 14, making it somewhat longer than the
finished case to allow for the formation of a head. Then the case is placed in a
suitable countersunk die k so that the closed end is held projected sufficiently and the
die containing the case is passed in the heading press shown in Fig. 15 beneath
the heading punch p thereof, which descends by means of the handle to flatten the
closed end of the tube or case into the countersink. The surplus length of metal in
the case is thus taken up in the formation of the head as shown at 2 and 3 in Fig. 14.
In the heading press the dies k and p are connected with the conductors and and.
The dies are
the current flows from one die to the other through the cartridge case.
insulated from each other by insulation to prevent the current short-circuiting
through the frame. The diep of the heading press is returned to its original position
by means of the spring j'.
Although the stamping presses shown in the drawings are designed to be operated
by hand, will be obvious that they may be operated by any suitable and well known
means.
It will be also apparent that the sheet of metal or disk may be by this method main-
tained in a heated, softened or annealed condition during the entire formation of the
article if desired, and that, with suitable current regulating devices in circuit, the
sheet may be kept at any temperature desired without danger of burning or heating
the sheet metal too much.
The sheet metal may be fed to the forming apparatuses and the formed articles with-
drawn therefrom in any suitable manner and by any suitable and well known means
heretofore used in connection with similar sheet-metal forming apparatus.
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 method of utilizing electricity in the formation of sheet-metal articles,

page_text: consisting in electrically heating a sheet of metal, applying a suitable force to form
the sheet as desired, and maintaining said sheet of metal in the heated condition while
it is thus formed.
2 The method of utilizing electricity in the formation of sheet-metal articles, con-
sisting in passing a current of electricity through a sheet of metal to soften the same
and then gradually forming said sheet by pressure over a die.or mould.
3-The method of utilizing electricity in the formation of sheet-metal articles con-
sisting in electrically heating a sheet of metal while in position upon a die or mould
and applying pressure to gradually form the sheet to correspond to the form of the
surface of the die or mould.
4-The method of utilizing electricity in the formation of sheet-metal articles,
consisting in passing a current of electricity through a sheet of metal between two
points, to soften the same, and then gradually applying pressure to form the sheet
over a suitable circular die or mould.
5-The method of utilizing electricity in the formation of sheet-metal articles
consisting in passing a current of electricity through a sheet of metal between two
points, one at or near the centre and the other nearer the edge or periphery of the
sheet, to soften the same, and then applying pressure to the sheet to form the same
over a suitable die or mould surface.
6 The method of utilizing electricity in the formation of sheet-metal articles
consisting in electrically heating a sheet of metal while it is rotated and gradually
formed or spun over or upon a suitable die or mould.
7 The method of utilizing electricity in the formation of sheet-metal articles
consisting in electrically heating a sheet of metal by passing a current of electricity
through the same while it is rotated and formed or spun upon a suitable die or mould
surface.
8 The method of utilizing electricity in the formation of sheet-metal articles
consisting in electrically heating a sheet of metal by passing a current of electricity
through the same while it is rotated and formed or spun upon a suitable die or mould
surface, and passing said current between two points, one at or near where the
sheet is held by the rotating device and the other where the pressure instrument is
applied.
9 The method of utilizing electricity in the forming of sheet-metal articles, con-
sisting in communicating a rapid circular motion to a sheet of metal held against a
mould, passing a heating current of electricity through the sheet to soften the same,
and then by means of a suitable instrument applying pressure to successive points
upon the sheet to form said sheet to correspond to the form of the surface of the
mould.
10 The method of utilizing electricity in the forming of sheet-metal articles,
consisting in communicating a rapid circular motion to a sheet of metal and a mould
held against it, passing a heating current of electricity through the sheet to soften the
same, and then applying pressure with a movable instrument upon successive parts of
the sheet and towards tho mould to conform said sheet to the form of the surface of
the mould.
11 The method of utilizing electricity in the forming of sheet-metal articles, con-
sisting in communicating a rapid circular motion to a flat disk-shaped sheet of metal
and a mould held against it, passing a heating current of electricity through the sheet
to soften the same, and then applying pressure with a movable instrument upen
successive parts of the sheet and towards the mould to conform said sheet to the form
of the surface of the mould.
12-The method of utilizing electricity in the forming of sheet metal articles, con-
sisting in communicating a rapid circular motion to a sheet of metal and a mould held
against it, electrically heating the sheet while in motion to soften the same, and then
applying pressure with an instrument upon successive parts of the sheet beginning at
or near the centre and gradually approaching the edge, and towards the mould, to
conform said sheet to the form of the surface of the mould.
13-The method of utilizing electricity in the formation of sheet-metal articles

page_text: consisting in electrically heating a sheet of metal to soften the same, and then
gradually applying pressure to form the sheet over a suitable circular die or
mould.
14 In an electric apparatus for forming sheet-metal articles, the combination with
a die or mould, of means for holding and rotating said die or mould with the sheet of
metal to be operated upon, connections to pass an electric current through the sheet
while it is rotated, and means for imparting pressure to the sheet to conform the same
to the surface of said die or mould.
15 In an electric apparatus for forming sheet-metal articles, the combination with
a suitable die or mould, of means for holding and rotating said die or mould with the
sheet of metal to be operated upon, a pressure instrument to gradually conform the
sheet to the form of the surface of the said mould, and terminals of an electric circuit
in contact with the sheet, one at its centre or axis and the other at a point nearer the
edge or periphery of the sheet.
16 In an electric apparatus for forming sheet-metal articles, the combination with
a suitable die or mould, of means for holding and rotating said die or mould with the
sheet of metal to be operated upon, a pressure instrument to gradually conform the
sheet to the form of the surface of the said mould, and terminals of an electric circuit
connected to the sheet, one terminal constituting the head-stock of the rotating means
and the other terminal the pressure instrument.
17 In an electric apparatus for forming sheet-metal articles, the combination with
a suitable die or mould, of means for holding and rotating said die or mould with the
sheet of metal to be operated upon, a pressure instrument having a revolving bearing
to gradually conform the sheet to the form of the surface of the said mould, and
terminals of an electric circuit in contact with the sheet.
18 In an electric apparatus for forming sheet-metal articles, the combination with
a suitable die or mould, of means for holding and rotating said die or mould with the
sheet of metal to be operated upon, a universally movable pressure instrument to
gradually conform the sheet to the form of the surface of the said mould, and terminals
of an electric circuit in contact with the sheet.
19 In an apparatus for electrically forming sheet-metal articles, the combination,
of a die or mould, means for holding the sheet against said die or mould and a
movable pressure instrument to conform the sheet to the shape of the surface of the
mould, and electric terminals in contact with the sheet.
20 In an apparatus for electrically forming sheet-metal articles, the combination
of a die or mould, means for holding the sheet against said die or mould and a
movable pressure instrument to conform the sheet to the shape of the surface of the
mould, and electric connections leading to said means for holding the sheet against
the mould and to the movable pressure instrument.
21 In an electric apparatus for forming sheet-metal articles, the combination with
a drawing die and punch, of connections to pass an electric current through the sheet
while it is operated upon or formed, and means for imparting pressure with the
said die and punch upon the sheet to conform the latter to the surface of the die and
punch.
22 In an electric apparatus for forming sheet-metal articles, the combination with
a drawing die and punch, of electric connections connected with the blank holders to
pass an electric current through the sheet while it is operated upon or formed, and
means for imparting pressure with the said die and punch upon the sheet to conform
the latter to the surface of the die and punch.
23 In an electric apparatus for forming sheet-metal articles, the combination with
a circular drawing die and punch, of connections to pass an electric current through
the sheet while it is operated upon or formed, and means for imparting pressure with
the said die and punch upon the sheet to conform the latter to the surfaces of the die
and punch.
24-In an electric apparatus for forming sheet-metal articles, the combination with
an insulated drawing die and punch, of connections to pass an electric current
through the sheet while it is operated upon or formed, and means for imparting

page_text: pressure with the said die and punch upon the sheet to conform the latter to the
surfaces of the die and punch.
25-In an electric apparatus for forming sheet-metal articles, the combination with
a drawing die and punch, of connections to pass an electric current through the sheet
while it is operated upon or formed, and means for imparting pressure with the said
die and punch upon the sheet to conform the latter to the surfaces of the die and
punch, and means for cutting the formed article from the blank when it is nearly or
entirely formed.
Natal this 50th 1..
1900
°
MARK WESLEY DEWEY.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.