Machine Guns.
Year: 1888

page_text: Date of Application, 25th Jan., 1888
Complete Specification Left. 22nd Oct., 1888
Complete Specification Accepted, 23rd Nov., 1888
Machine Guns.
I, WILHELM LORENZ of 61 Kriegstrasse Karlsruhe in the Grand Duchy of Baden,
German Empire, Engineer and Manufacturer do hereby declare the nature of this
invention to be as follows:-
The metallic bases of cartridge cases for fire arms ordnance and machine guns have
heretofore been made with a flat face, so as to be held in the cartridge chamber of the
gun by the abutting flat face of the breech block or bolt.
The percussion cap being fitted into the cap chamber with its outer end flush with
the flat end face of the base, there is considerable liability to an accidental explosion
of the cartridge through the striking of the cap against any hard object when being
handled, and in order to avoid this danger as much as possible with large cartridges
for ordnance it has been customary to temporarily secure by metal straps a pad of
soft material over the end of the cap until the cartridge is to be used.
My present invention has for its object an improved construction of the bases of
cartridges whereby such above mentioned danger of accidental firing is avoided, and
the use of the safety device referred to, consequently rendered unnecessary. It consists
in making the base of the cartridge of concave or dished form so that while the
peripheral part of the base remains in the same plane as heretofore, the central part
and consequently also the head of the percussion cap is sunk to a greater or less
distance within such plane, and thus any hard surface with which the base of
the cartridge may be accidentally brought into contact, cannot strike against
the cap.
The said dished or concave form of the cartridge base can be produced at the same
time that the case is formed by stamping and drawing in the usual manner, in which
case this form of the base offers the further advantage of enabling the peripheral part
thereof to be made comparatively thick to afford the requisite strength, while the
central dished portion surrounding the cap chamber can be made considerably thinner.
Or the base of the cartridge may be made flat as usual in the first instance, and be
then bulged inwards by means of suitable dies.

page_text: With cartridge cases constructed according to my above described invention, the
breech block or bolt of the gun would have to be made of a convex form so as to fit
into and support the concave base of the cartridge on firing, but this construction is
not intended to be claimed under this application.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Cartridge Cases for Fire Arms, Ordnance, and
Machine Guns.
I, WILHELM LORENZ of 61 Kriegstrasse Karlsruhe in the Grand Duchy of Baden
German Empire, Engineer and 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 :-
The metallic bases of cartridge cases for fire arms ordnance and machine-guns have
heretofore been made with a flat face so as to be held in the cartridge chamber of the
gun by the abutting flat face of the breech block or bolt.
The percussion cap being fitted into the cap chamber with its outer end flush with
the flat end face of the base, there is considerable liability to an accidental explosion
of the cartridge through the striking of the cap against any hard object when being
handled, and in order to avoid this danger as much as possible with large cartridges
for ordnance it has been customary to temporarily secure by metal straps a pad of
soft material over the end of the cap until the cartridge is to be used.
My present invention has for its object an improved construction of the bases of
cartridges whereby such above mentioned danger of accidental firing is avoided and
the use of the safety device referred to consequently rendered unnecessary. It consists
in making the base of the cartridge of concave or dished form so that while the
peripheral part of the base remains in the same plane as heretofore, the central part
and consequently also the head of the percussion cap is sunk to a greater or less
distance within such plane and thus any hard surface with which the base of
the cartridge may be accidentally brought into contact, cannot strike against the cap.
The said dished or concave form of the cartridge base can be produced at the same
time that the case is formed by stamping and drawing in the usual manner in which
case this form of the base offers the further advantage of enabling the peripheral part
thereof to be made comparatively thick to afford the requisito strength, while the

page_text: central, dished portion surrounding the cap chamber can be made considerably thinner.
Or the face of the cartridge may be made flat as usual in the first instance, and be
then bulged inwards by means of suitable dies.
With cartridge cases constructed according to my above described invention, the
breech block or bolt of the gun would have to be made of a convex form so as to fit
into and support the concave base of the cartridge on firing but this construction is
not intended to be claimed under this application.
The accompanying drawing shews by way of example three different modes of
recessing the bases of cartridges according to my invention.
In Fig. 1 the entire base within the outer rim is made of a dished or concave form,
so as to bring the outer end of the cap chamber within the plane of the rim.
In Fig. 2 only the central portion is recessed or dished, and in Fig. 3, which
represents a cartridge case of large size such as are used for ordnance and machine
guns, a comparatively small central recess is formed, only extending slightly beyond
the cap chamber.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
Constructing the bases of cartridge cases entirely or partially of a concave, dished
or recessed form so that the outer end of the cap chamber is sunk within the plane of
the rim substantially as and for the purposes described.
ABEL & IMRAY,
Agents for the Applicant.