IMPROVEMENTS IN CARTRIDGE CASES
Year: 1881

page_text: LETTERS PATENT to George Kynoch, of Witton, near Birmingham, in the
County of Stafford, for an Invention of "IMPROVEMENTS IN CARTRIDGE
CASES"
PROVISIONAL SPECIFICATION left by the said George Kynoch at the
Office of the Commissioners of Patents on the 1st November 1881.
GEORGE KYNOCH, of Witton, near Birmingham, in the County of Stafford.
"IMPROVEMENTS IN CARTRIDOE CASES."
My Invention relates to the construction of metallic cartridge cases in such a
manner as to get great soundness and durability consistently with great lightness
of material and economy of manufacture. For this purpose I make the cartridge
case in two parts, the tube and the head, but instead of making the tube, as in
many kinds of composite cartridge cases, without a bottom, or with a hole through
its bottom, and then securing it to the head by compressed pulp or otherwise, I
make the tube by drawing in the ordinary way with a complete bottom, and I
indent this bottom with a recess to receive the inwardly projecting percussion
chamber of the head. As the bottom of the tube does not require the strength
needed in ordinary cartridge cases, I draw it and the tube thinner than usual. I
prepare a separate cup, which is to form the head of the cartridge case, and which
has, as usual, the inwardly projecting percussion cap chamber. I insert the bottom
of the tube into the cup, and subject the two together to drawing and heading
pressure, by which the tube and the cup become soundly united. The finished
cartridge case thus manufactured presents a double bottom, the inner thin bottom
which is in one piece with the tube, and the outer thicker bottom which is of
sufficient strength to sustain the percussion, and which has the projecting lip for
extraction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Kynoch in the Great Seal Patent Office on the 4th April
"
1882.
GEORGE KYNOCH, of Witton, near Birmingham, in the County of Stafford.
IMPROVEMENTS IN CARTRIDGE CASES."
My Invention relates to the construction of metallic cartridge cases in such a
manner as to secure great soundness and durability consistently with great
lightness of material and economy of manufacture. The construction which I will
describe applies to cartridge cases, whether for sporting or for military purposes,
as I will explain referring to the accompanying Drawings. Of these Figures 1, 2,
3, 4, and 5 relate to a common form of case for sporting cartridges, and Figs. 6, 7,
8, 9, and 10 to a well known forin of case for military cartridges. For cartridge
cases of other forms and proportions a like construction is applicable, as may be
readily understood. I make the cartridge case in two parts, the tube and the
head, but instead of making the tube, as in many kinds of composite cartridge
cases, without a bottom, or with a hole through its bottom, and then securing it to
the head by pulp or otherwise, I make the tube by drawing in the ordinary way,
with a complete bottom indented with a recess to receive the inwardly projecting
percussion chamber of the head. Figs. 1 and 6 shew in longitudinal section the tube
thus prepared. As the head which I shall presently describe strengthens the bottom, I
do not require to make the bottom of the drawn tube itself of considerable thickness
relatively to the tube, and consequently as the tube is of nearly uniform thickness
throughout its whole substance, I am enabled to draw it very thin without exposing
any parts of it-to-unequal strains-I-prepare by punching and drawing a cup, such
as those shewn in Figs. 2 and 7, which cup is to form the head of the cartridge
case, and which has formed in it the inwardly projecting percussion chamber.
Having prepared the tube, as shewn in Figs. 1 and 6, the cup, as shewn in Figs. 2
and 7, 1 insert the bottom of the tube into the cup, as shewn in Figs. 3 and 8, and
I then subject the two together to drawing and heading pressure so as to give the
finished form shewn in Figs. 4 and 9, the cup being by this operation soundly
united to the tube. Holes are then pierced, as shown by the plan, Figs. 5 and 10,
for passage of flame from the percussion cap into the charge, and the case is
complete, ready for charging; or a single central hole may be pierced to receive an
anvil of any known kind suitable for the percussion cap. The finished cartridge
cuse thus manufactured without requiring any internal lining presents a strong
double bottom, consisting of the inner thin bottom, which is of one piece with the
tube, and of the outer thicker bottom, which is sufficiently strong to sustain the
percussion, and which has the usual projecting lip or flange for extraction. As the
inner bottom is in one piece with the tube there is no joint at the angles of the
bottom liable to produce fracture or to permit escape of powder gas.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I hereby declare that I make no general claim to doubling
in whole or in part the metal of a cartridge case, but I claim,—
The manufacture of cartridge cases with double bottoms, substantially as and for
the purposes herein set forth.
In witness whereof, I, the said George Kynoch, have hereunto set my hand
and seal, this Twenty-seventh day of March, in the year of our Lord One
thousand eight hundred and eighty-two.