Improvements in the Manufacture of Conical Metal Cases, Especially Applicable for Use as Cartridge Cases.
Year: 1888

page_text: Improvements in the Manufacture of Conical Metal Cases, Especially
Applicable for Use as Cartridge Cases.
We, GUSTAF WIKTOR ROMAN, of Olofström, in the County of Blekinge, Sweden,
Manager. and OTTO ANDERSSON, of Olofström, in the County of Blekinge, Sweden,
Engineer, do hereby declare the nature of this invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the following
statement :-
Our invention relates to an improved method of manufacturing conical-shaped
metal-cases, which are especially applicable for use as cartridge-cases for breach-
loading guns.
In the accompanying drawing.
Figures 1 and 2 shows in elevation and section a conical punch for making such
cases, the said case being shown in section on the punch.
Figure 3 shows a punch with the moveable disc and the closed case.
Figure 4 shows a punch for punching the bottom caps and,
Figure 5 shows a section partly in elevation of a cartridge-case made according to
our invention.
These cases are made by punching plates in the following manner.
A pressed thin plate cylinder is forced upon a punch a (Figure 1), with a
cylindrical portion at one end and which has also a short conical enlargement,
the said punch being for the rest of its length slightly conical. When the cylinder,
through the punching, has been forced into the form of the punch a, it is taken
away for cutting off the bottom c. The case thus formed is put on a cylindrical
punch (Figure 3), which at one of its ends is turned down to a smaller diameter
as at e. This smaller part is surrounded by a ring f made in three parts 1, 2, 3,
forming a moveable disc (Figure 3). By putting the case b on the punch, its
cylindrical part is to be placed nearest the top of the punch, where it is fastened
by a screw clip g; its other end projects above the punch. This end is then
closed around the disc f (Figure 3), and the case is then cut off at m.
When the case is to be fitted with bottom caps, for the purpose of strengthening
it, such caps h h¹ are punched in different lengths upon a special punch i

page_text: (Figure 4) of the same gauge as the moveable disc. Before the closing of the
end of the case these caps are put upon the disc into the case b, as shown in
Figure 3. Then the screw clip g is loosened and the case removed from the
punch d, whereby the disc f falls to pieces and can be removed through the
muzzle of the case.
Figure 5 shows a cartridge-case, made in this manner and fitted with a bottom
flange k. Such conical cartridge-cases made from steel-plates seems to offer, by
reason of their small weight and cheapness, great advantages as compared with
the heavy cartridge-cases now in use.
In order to prevent the bursting of the cases by the firing, at their bottom
flange there can be made openings 1, through which the gas of the explosion can
escape into the space behind the case, thus equalizing the pressure on both sides,
in order that the bottom flange may not suffer any shock.
The principal cause of the bursting of the common cartridge-cases by firing the
gun is the want of communication between the interior of the case and the
barrel of the gun, consequently by the explosion of the loading, the bottom of
the case especially is exposed to a violent shock from the inside so that it will
burst.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare, that what we
claim is,
First An improved method for manufacturing conical metal-cases from plates,
which consists in first forcing a plate-cylinder upon a conical punch (a) so that
the cylinder assumes the form of the said punch, then cutting away the bottom (c) of
the cylinder and putting the case, the smaller part before, on a cylindrical
punch (d) the one end of which is turned smaller and surrounded by a movable
disc (f) composed of several parts and further in putting one more conical
punched caps (h) one covering the other on the movable disc, and then closing
the part of the case (b) projecting above the punch; in cutting away the part of
the case just at the point of closing and finally in removing the punch and the
movable disc as above described.
or
Second A case, inward and outward conical shaped, and eventually fitted with
bottom caps (h) manufactured in the above described manner.
Third A plate cartridge-case (b) for breech loading guns, the bottom flange of
which is pierced with openings (1) for the purpose of establishing communication
between the inside and outside of the bottom, all substantially as described.
D
17th loof 1888
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.