Improvements in Metallic Cartridge-cases.
Year: 1891

page_text: Date of Application, 5th Dec., 1891
Complete Specification Left, 4th Oct., 1892-Accepted, 5th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in Metallic Cartridge-cases.
We, ARTHUR CHAMBERLAIN of No. 4 New Bartholomew Street, Birmingham
Manufacturer, and GEORGE HOOKHAM of Nos. 7 and 8 New Bartholomew Street,
Birmingham Manufacturer do hereby declare the nature of this invention to be as
follows:-
Our improvements consist partly in the formation of the heads of cartridge-cases,
partly in the material of which these cases are made. Hitherto it has been found
necessary to make a composite head, the base being formed of harder metal than
that composing the body of the case, in order to support the backward force of the
explosion at that part where the breech of the larger calibres of quick-firing guns
is recessed. We prefer to make the head solid with the rest of the case, either
letting in a ring of manganese bronze, or other hard alloy, the mean diameter of
which is about equal to the diameter of the recess in the breech, or we may simply
form a hollow circular channel of a similar mean diameter, or we may recess the
whole of the centre part of the head, making the diameter of the recess in the
cartridge about a quarter of an inch larger than the diameter of the recess in
the breech of the gun. In order to prevent the burning of the mouth of the case,
a defect which has been found to occur in connexion with the use of some
explosives, we form the case of the alloy known as Muntz's metal, which is not
injured by the heat generated by the explosion.
Dated this 4th day of December 1891.
ARTHUR CHAMBERLAIN.
GEORGE HOOKHAM.
COMPLETE SPECIFICATION.
Improvements in Metallic Cartridge-cases.
We, ARTHUR CHAMBERLAIN, of 4 New Bartholomew Street, Birmingham,
Manufacturer, and GEORGE HOOKHAм of Nos. 7 and 8 New Bartholomew Street,
Birmingham, Manufacturer, 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 improvements consist partly in the formation of the heads of cartridge cases,
partly in the material of which these cases are made. Hitherto it has been found
necessary in some cases to make a composite head, the base being formed of
harder metal than that composing the body of the case, in order to support the
backward force of the explosion at that part where the breech of the larger calibres
of quick-firing guns is recessed. We prefer to make the head solid with the rest
of the case, either letting in a ring of manganese bronze, or other hard alloy, the
mean diameter of which is about equal to the diameter of the recess in the breech,
or we may simply form a hollow circular channel of a similar mean diameter, or
we may recess the metal of the centre part of the head, making the diameter of the
recess in the cartridge about a quarter of an inch larger than the diameter of
the recess in the breech of the gun. In order to prevent the burning of the
mouth of the case, a defect which has been found to occur in connection with
the use of some explosives, as cordite, we form the case of the alloy known as
Muntz's metal or other alloy which is not injured by the heat generated by the
explosion.

page_text: Referring to the accompanying sheet of drawings-
Figures 1 and 2 are sections illustrating cartridge cases constructed in accordance
with our invention.
The circular groove A, A Figure 1 is cut in the head D and is arranged of such
diameter that when the case is in position in the gun, the edge of the circular
recess B in the breech of the gun lies within the groove preferably as shown in
Figure 1 about the centre of the groove. The centre part of the cartridge case
edge is thus isolated from the external portions and so all inconvenient distortions
are avoided.
Instead of the groove A, A Figure 1, the recess C, C Figure 2 may be provided,
and it is arranged to be a little larger in diameter than the recess B; that is it has
the same relation to B as the groove A, A has to it.
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 :-
1. In solid cartridge cases for large calibre quick-firing guns a groove or recess
as A Figure 1 or as C Figure 2 for the purpose hereinbefore described.
2. In cartridge cases for cordite charges the use of a metallic alloy which is not
brittle at high temperatures substantially as herein before described.
Dated this 3rd day of October 1892.
ARTHUR
CHAMBERLAIN.
GEORGE HOOKHAM,
7 & 8, New Bartholomew Street, Birmingham.