Improvements in Methods of Utilizing Electricity in the Formation of Metallic Cartridge Cases and other Articles.
Year: 1890

page_text: Date of Application, 15th Oct., 1890-Accepted, 15th Nov., 1890
COMPLETE SPECIFICATION.
Improvements in Methods of Utilizing Electricity in the Formation
of Metallic Cartridge Cases and other 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 METHODS OF UTILIZING
ELECTRICITY IN THE FORMATION OF METALLIC CARTRIDGE CASES AND OTHER
ARTICLES and in what manner the same is to he performed, to he particularly
described and ascertained in and by the following statement :-
"2
My invention relates to the process of manufacturing cartridge cases from sheet
metal or thin metal of uniform thickness.
The purpose of my invention is to keep the metal annealed or in a softened condition
during a part of, if not the entire formation of the cartridge case, and to decrease the
number of dies as well as the number of pressings heretofore required in forming or
shaping the case, and, also, to save time and handling.
The object of my invention, also, is to provide a process or method, by which,
stronger and superior cartridge cases can be produced, the formation of cases from
thicker sheet metal is allowed, and various metals can be employed in the manufacture
of cases heretofore incapable of being pressed.
My invention consists essentially in electrically heating the metal to be formed into
the case, preferably by passing an electric heating current through the same before or
while the case is formed, or before its completion.
My invention consists also in electrically heating the metal sheet or disk while it is
formed over or within a punch or die by pressure suitably and gradually applied and
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, and
also in certain apparatus and devices useful in practising the processes.
In the accompanying drawings,
Fig. 1 is a side elevation, parily in section of my cartridge stamping apparatus to be
used in practising my method.
Fig. 2 shows a heading machine for heading the case by my method, and
Fig. 3 illustrates the shape the case assumes at different stages of the process.
Referring specifically to the drawings, Fig. 1 represents a screw stamping or
drawing press adapted to form the cases according to my method and consists of a
metal frame A securely bolted to a table or bench A and containing or supporting the
stamping devices.
The press is shown partly in section to more clearly show internal parts of the
apparatus, and to aid in describing the same.
B is a strip of sheet metal between the punch and the drawing die D and is
shown slightly raised above said die, but in practice rests upon the same.
E is a stationary annular cutting punch encircling the drawing punch (, but
insulated therefrom by insulation a. One of the terminals F of the heating circuit is
connected to this cutting punch while the other terminal is connected to the punch C
through the upper part of the frame A which is insulated from the lower part of the
frane by insulation to prevent the current short circuiting through the apparatus.
G is the screw that operates or lowers the punch, C, and H is the screw that raised
the drawing die D with its annular cutting die I to cut a disk from the sheet B and to
make electric contact between the centre of the disk and the punch C, and the
circumferential portion of said disk and the cutting punch E.
Electric contact is made as soon as the cutting punch and die press the metal on

page_text: opposite sides. The metal is then rapidly heated and softened by the current passing
through the same from the punch C to the cutting punch E which also constitutes the
clamp or holder for the circumferential portion of the disk. The cutting punch E is
hollowed out on its underside so that it cannot come in contact with the sheet
immediately except at and near its cutting edge, and the lower end of the punch C is
on a line with or slightly below said cutting edge of the punch, so that contact will be
made between both of said parts and the sheet at the same time, and, to make the
path for the current through the disk as long as possible, and to evenly heat the
same.
When the metal is heated sufficiently the dies D and I are raised still more to cut
the disk from the strip or sheet and clamp the same to hold the metal smooth
between E and ID. Then the screw G is used to rapidly force the punch C down-
ward so that the metal disk is pressed into the die D and made to receive a
corresponding form or cup shape. As the sheet or disk is thus forced into the die,
its circumferential portions are drawn out from under the clamp, and the strain or
tension thus exerted upon the metal effectually insures smoothness in the completed
article, and also enables a deeper cup to be produced at a single operation.
The current may be interrupted if desired during the latter part of the operation or
may not be applied until after the case is partly formed as the metal may be pressed
to a certain extent before it is necessary to heat it; but, the operation is so rapid
that it is preferably heated at the commencement of the operation as hereinbefore
described.
I do not limit myself therefore, to electrically heating the metal for the case while
it is being pressed, nor while it is in position in the press as it may be removed
therefrom after it is partly formed, electrically heated or softened, and then re-inserted
in a press and finished.
A cam press may be employed instead of a screw press if desired.
I do not limit myself to formning the case complete by a single impression as it may
be necessary or desirable to make several impressions thereon before it is completed.
It will be apparent from the foregoing description, that in forming a cartridge case
by my method; I preferably first cut a disk as shown at 1 in Fig. 3 from a sheet or
strip of thin metal, then form the case while it is electrically heated by a suitable force
to press said disk within a die to form a cup 2 somewhat longer than the finished case
to allow for the formation of the head. The case is then trimmed as usual to remove
its rough edge formed by pressing. Then the case is placed in a suitable countersunk
die so that the closed end is held projected sufficiently and the die containing the
case is passed in the heading press shown in Fig. 2 beneath the heading punch p
thereof which descends by means of the handle j 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 3 and 4 in Fig. 3.
In the heading press the dies & and p are connected with the conductors c and c¹
and the current Hows from one die to the other through the cartridge case. The dies
are insulated from each other by insulation to prevent the current short-circuiting
through the frame. The die p 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, it will he 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
maintained in a heated, softened or annealed condition during the entire formation of
the case 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 cases with-
drawn therefrom in any suitable manner and by any suitable and well known means
heretofore used in connection with similar cartridge forming apparatus.

page_text: 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 herein described improvement in processes of manufacturing cartridge cases,
which consists in forming the case by drawing or stamping the same from thin metal,
and electrically heating the case during its formation as and for the purpose described.
2. The herein described improvement in processes of manufacturing cartridge cases,
which consists in forming the case by drawing or stamping the same from a sheet of
thin metal, and electrically maintaining the case in a heated condition during its
formation..
3. The herein described improvement in processes of manufacturing cartridge cases,
which consists in forming the case by drawing or stamping the same from a sheet of
thin metal and annealing the case during its formation or before its completion by
passing a heating current of electricity through the same.
4. The herein described improvement in processes of manufacturing cartridge cases,
which consists in forming the case by drawing or stamping the same from a sheet of
thin metal, and electrically heating the case during its formation by passing a heating
current of electricity through the same and from one die to the other as and for the
purpose described.
5. The herein described improvement in processes of manufacturing cartridge cases,
consisting in cutting a disk of metal from a sheet, then drawing or stamping the full
length cup from the disk at one operation while the blank is electrically heated and
then heading and finishing the cup as desired to complete the case.
6. The herein described improvement in processes of manufacturing cartridge cases
which consist in forming the case from a single piece of metal of uniform thickness,
by drawing, swaging or otherwise shaping it as desired, and electrically heating the
metal during its formation or before the case is completed.
Dated hood La
1900
MARK WESLEY DEWEY.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.