IMPROVEMENTS IN CARTRIDGES FOR BREECH-LOADING FIRE- ARMS
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
24th August 1868.-A communication from abroad by Samuel
Norris, of Springfield, Massachusetts, United States of America.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
No. 8, Southampton Buildings, Chancery Lane, in the County of
Middlesex, Consulting Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN CARTRIDGES FOR BREECH-LOADING FIRE-
ARMS," a communication, to be as follows:-
The said improvements relate to metallic cartridges formed of tubes
or cylinders of copper, brass, or other suitable metal, and provided at
the base with means for containing the fulminate or detonating com-
pound. Such cartridges have hitherto been commonly manufactured by
crimping or folding the base to form the exterior rim or flange, which
has therefore always been the weakest part of the cartridge, both from
the thinness of the metal at that part and the effect of the bending or
folding. The provision for receiving the fulminate has been made by
inserting in the base of the cartridge devices which have all been more

page_text: or less imperfect with regard to their security in the shell and the
prevention of the escape of gas at the rear of the same.
In constructing my improved cartridge the rear end or base is formed
solidly with the tube or cylindrical part of the shell, the interior corner
or angle at the junction of the base and cylindrical portion being filled
up with the solid metal by curving or bevelling the surface of the tube
to meet the interior of the base. At the centre of the inside of the base
and in the solid metal of the same I form a cup or cavity with a raised
flange to receive the fulminate, and this flange may be either flattened
over the fulminate to form the anvil or may be turned over upon a
separate disc employed for that purpose. After the cartridge has been
exploded it may be again fitted for use by boring out or otherwise
removing the central portion of the base, and fitting therein a cap and
anvil of any suitable description. I first take a cartridge tube of copper,
brass, or other suitable metal, having its closed end which is to form the
base of the cartridge of greater thickness than the cylindrical portion of
the said cartridge; this tube or shell is placed in a block die, and is
subjected to the action of a punch 'inserted into the tube "and a com-
pressing tool which acts on the exterior of the base. By the action of
this apparatus the metal of the closed end or base of the tube is
compressed and spread around the exterior of the same, thereby forming
the rim or flange of the cartridge. By the pressure thus exerted upon
the metal of the base, and either at the same operation or separately, as
desired, the inner central cup or cavity is formed. To allow this to be
effected the tool inserted inside the tube or shell inust 'have its face
formed with an annular central recess corresponding in size with the
rim to be raised inside the base. Then when the said base is compressed
between this tool and the compressing tool outside the base the metal of
the latter will be forced into the annular recess, thereby forming the said
rim solidly with the base and tube. The metal of the base inside this
raised rim should be thinner than the other portions of the base to render
it more sensitive to the action of the firing pin or other striker of the
fire-arm in, which the cartridge is used; and I prefer to effect this
reduction of the thickness by making the tool or punch with the central
portion of its face projecting slightly beyond its exterior portion. After
the interior raised rim has been formed in the manner above described,
the fulminate is placed in the central cavity or recess within the said
rim. I then either turn down the rim over the fulminate, or place over
..
1.
dy
.

page_text: the latter a separate metal disc or anvil, and force the rim down upon
the said disc. I prefer to adopt the former method, which is the more
simple of the two, and forms an equally good anvil or support for the
fulminate. The turning or forcing inward of the rim is effected by
means of one or more punches, with ends so formed that when sufficient
pressure is exerted upon them the rim is first bent inward and then
forced down over the fulminate in the central chamber, a hole or
aperture being left in the centre of the rim when the same is thus forced
inward to allow the fulminate when fired to communicate with the
charge in the body of the shell.