Improvements in Cartridges.
Year: 1889

page_text: Date of Application, 13th Mar., 1889
Complete Specification Left, 9th Nov., 1889-Accepted, 14th Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in Cartridges.
1, PIERRE AMBJORN, Comte de Sparre of 1 Boulevard St. Denis, Paris, France,
Engineer, do hereby declare the nature of this invention to be as follows:-
:-
In the cartridges now used, whether for portable firearms or for artillery there is a
defect due to the difficulty which these cartridges have in resisting laterally the
pressure of the gas. In portable firearms it is more particularly in front of the
shoulder, that is to say at the point where the extractor lies that the resistance is
borne by the cartridge case alone, and this is a source of danger of explosion. For
larger guns this danger is at the obturating ring employed to ensure the closing of
the breech.
In order to overcome this defect 1 construct cartridges in such manner that the
pressure of the gas is exerted in front of those dangerous places and in such manner
that the pressure there is insignificant.
With this object I employ at the rear of the cartridge a cylinder of steel or
other suitable metal, to the front of which is fixed by means of a rivet a cup or
thimble which fits the cartridge case and is made either in one piece or of several
cups fitted one within another. The head of the rivet is arranged to receive the
cap in the ordinary way and it has a hole throughout its entire length for the
ignition of the powder. This apparatus, consisting of the cylinder, cup and rivet
is introduced into the cartridge case which is closed by the metal base in the
ordinary manner.
It is evident that if the thickness of the cup around the edge of its rear or closed
end is greater than the space comprised between the steel cylinder and the inner
wall of the barrel, the gas will be completely stopped at this place so that behind
the cup there will be no expansion of gas and this can only produce compressive
force in the direction of the bore of the barrel and not in a lateral direction.
My method of construction has the further advantage of allowing the cartridge to
be formed of several pieces and therefore the resisting power of the metal is not
affected, a result which is impossible with cartridges made in a single piece drawn by
means of a number of operations which disaggregate the metal.
For large guns my invention is still more important because it enables me to
dispense with the obturating rings which are very inconvenient and expensive.
Dated this 13th day of March 1889.
J. C. MEWBURN,
55 & 56. Chancery Lane, London, Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Cartridges.
I, PIERRE AMBJORN, Comte de Sparre of 1 Boulevard St. Denis, Paris, France
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 :-
In the cartridges now used, whether for portable firearms or for artillery there is a
defect due to the difficulty which these cartridges have in resisting laterally the
pressure of the gas. In portable firearms it is more particularly in front of the
shoulder, that is to say at the point where the extractor lies, that the resistance is
borne by the cartridge case alone, and this is a source of danger of explosion. For
larger guns this danger is at the obiurating ring employed to ensure the closing of the
breech

page_text: In order to overcome this defect I construct cartridges in such manner that the
pressure of the gas is exerted in front of those dangerous places and in such manner
that the pressure there is insignificant.
In the annexed drawing I show in longitudinal section on an enlarged scale a cartridge
constructed according to my invention and suitable for a portable firearm. In this
cartridge a is a cylinder of steel or other suitable metal, to the front of which is
fixed by means of a rivet b a cup or thimble c, which fits the cartridge case and
is made either in one piece as shown or of several cups fitted one within another.
The head of the rivet is arranged to receive the cap in the ordinary way, and
it has a hole throughout its entire length for the ignition of the powder. This
apparatus consisting of the cylinder, cup and rivet is introduced into the cartridge
cased which is closed by the metal base in the ordinary manner.
It is evident that if the thickness of the cup around the edge of its rear or
closed end, that is to say at the angle g, is greater than the space comprised
between the steel cylinder a and the inner wall of the barrel, the gas will be com-
pletely stopped at this place so that behind the cup c there will be no expansion of
gas and this can only produce compressive force in the direction of the bore of the
barrel and not in a lateral direction.
My method of construction has the further advantage of allowing the cartridge to
be formed of several pieces and therefore the resisting power of the metal is not
affected, a result which is impossible with cartridges made in a single piece drawn
by means of a number of operations which disaggregate the metal.
For large guns my invention is still more important because it enables the
obturating rings which are very inconvenient and expensive to be dispensed with.
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 :-
The construction of cartridges substantially as hereinbefore described for the
purpose explained.
Dated this 9th day of November 1889.
ember 1889.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.