IMPROVEMENTS IN THE CONSTRUCTION AND MANUFACTURE OF PERCUSSION CAPS FOR THE IGNITION OF CARTRIDGES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by George Clark at the Office of the
Commissioners of Patents, with his Petition, on the 23rd December
1870.
I; GEORGE CLARK, of No. 10, Craven Buildings, Drury Lane, London,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION AND MANUFACTURE OF
PERCUSSION CAPS FOR THE IGNITION OF CARTRIDGES," to be as follows:-
The object of this Invention is to produce a percussion cap for the
ignition of cartridges on a new or improved plan, of which the following
´is a description :—
For each percussion cap a quantity of any fulminating substance or
compound in a dry or moist state is deposited on a disc or any other
form of thin metal, paper, or cardboard corresponding to the size of
the cartridge to which it is to be adapted, having one or more small
holes (for the passage of the flash from the fulminate to the charge)

page_text: perforated near to the centre. This disc or other form of metal or
cardboard having the fulminate deposited on it is fastened by means
of any suitable paste, gum, varnish, or cement to a cardboard or paper
wad, having a hole in its centre large enough to leave uncovered the
holes in the centre of the before-mentioned disc of metal or cardboard,
and a thin paper is pasted over the aforesaid wad. Another cardboard
wad having a hole in its centre corresponding to the before-mentioned
wad is, in like manner, fastened to the other side of the said disc or
other form of metal or cardboard on which the fulminating substance
is deposited, care being taken that the hole in the last-mentioned wad
is large enough to prevent contact between this latter wad, and the
fulminate, and then a disc of thin paper is pasted or otherwise fastened
on the top of the last-mentioned wad. The result of this arrangement
is first, that the fulminating substance deposited on the metal or card-
board as before described is protected on both sides from any blow or
pressure which might accidentally cause the fulminating substance
to explode as it would or might if not so protected, and, secondly, that
the explosion of the cap so constructed as above described may be
effected by perforation through or a blow on it by a sharp needle or a
blunt pin.
The above described mode of applying my Invention is suitable
for all kinds of cartridges not having a metallic base, or if with a metallic
base, having a hole for the passage of the needle or pin. But for
cartridges with a metallic base and without any hole in the base the
same application of any kind of fulminating substance may be adopted
by bringing the disc or other form of metal or cardboard on which
the fulminate is deposited in close proximity to the inner side of the
metallic base, and supporting the inner side of the said disc or other
form of metal or cardboard on a pin or plate secured to the case, so
that by this arrangement a blow struck with a pin on the centre of
the outside of the metallic base of the cartridge will instantaneously
cause the fulminating substance to explode and ignite the gunpowder
or other explosive substance with which the cartridge is charged.
The arrangement above described as to the deposit of the fulminate
on a thin piece of card or metal, may be varied by applying the
fulminate on the under instead of the upper side of such thin piece
of metal or cardboard.

page_text: Another part of this Invention is the use and application of com-
bustible paper or cloth to form the discs and wads before-mentioned
in order that they may be entirely consumed by the combustion of the
gunpowder or other explosive substance with which the cartridge is
5 charged, and that little or no residuum be left in the barrel.