IMPROVEMENTS IN ME- TALLIC CARTRIDGE CASES
Year: 1871

page_text: LETTERS PATENT to George Coburn Wilson, of Birmingham, in the
County of Warwick, for the Invention of "IMPROVEMENTS IN ME-
TALLIC CARTRIDGE CASES."-A communication from abroad by General
Hiram Berdan, of the City of New York, in the United States of
America, but now residing at Saint Petersburgh, in the Empire
of Russia.
PROVISIONAL SPECIFICATION left by the said George Coburn Wilson
at the Office of the Commissioners of Patents, with his Petition,
on the 3rd July 1871.
I, GEORGE COBURN WILSON, of Birmingham, in the County of
Warwick, do hereby declare the nature of the said Invention for "Iм-
PROVEMENTS IN METALLIC CARTRIDGE CASES," being a communication to
me from abroad by General Hiram Berdan, of the City of New York,
in the United States of America, but now resident at St. Petersburgli,
in the Empire of Russia, to be as follows:—
This Invention relates to the manufacture of metallic cartridges cases.
It is especially applicable to those of a small calibre, but it may be also
applied with great advantage to those of a larger calibre.

page_text: The first part of my Invention consists in forming a solid headed
cartridge case having an external flange at its base from one piece of
metal of such a thickness that after the body of the case has been drawn
to the required degree of thinness the formation of the cap cavity from
the remaining thick metal of the base shall cause the said thick metal
to be foulded upon itself, so as to bring the hub or exterior of the cap
cavity into close contact with the interior of the cartridge case instead
of leaving an annular space around the said hub or cap cavity as has
hitherto been the case. The use of thick metal as described also permits
a solid external flange to be formed upon the cartridge case of sufficient
thickness to fill the usual recess or counterbore of a breech-loading|
rifle. An exceedingly strong cartridge case is thus produced and from
very thin metal without there being any risk of breaking the internal
punch, which having no annular space to form becomes a much simpler
and stronger tool.
The second part of my Invention consists in forming a solid headed
cartridge case from one piece of metal in such a manner as to produce
an annular space around the hub or exterior of the cap cavity in
combination with a solid external flange of a less thickness than the
base of the cartridge case, and in combination also with an external
shoulder or boss of less diameter than the flange, the said shoulder or
boss being formed either at the front or at the rear of the flange,
so that although the flange bec not of itself sufficiently thick to fill the
ordinary recess or counterbore of a breech-loading rifle, yet the flange
and the shoulder or boss are sufficiently thick to do so.
Although one operation only is in some cases sufficient to form the
cap cavity and the solid external flange and shoulder, I prefer this to be
done by two separate operations, because by so doing I obtain uniformity
in the thickness of the head of the cartridge case notwithstanding
variation in the thickness of the metal employed to a greater extent
than by any method of manufacture hitherto known. For in this
manner the cap cavity is formed in the first operation, and the thickness
of the head is precisely determined, the superfluous metal having room
to expand sideways in the counterbore of the die. In the second
operation the external flange is perfected, and any variation in the
thickness of the metal employed simply affects the thickness of the
external flange, which is a matter of small importance.

page_text: Another advantage obtained by the second part of my Invention is,
that cartridge cases can be made of thinner metal than usual, and yet
they will possess very great strength. The use of thinner metal has the
advantage of reducing the strain upon the internal punch and of
allowing the priming holes to be formed by punching through the metal.
of the cap cavity instead of by the longer process of drilling which is
necessary when thick metal is empoyled.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Coburn Wilson in the Great Seal Patent
Office on the 3rd January 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
COBURN WILSON, of Birmingham, in the County of Warwick, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of July, in the year of our
Lord One thousand eight hundred and seventy-one, in the thirty-fifth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said George Coburn Wilson, my exccutors, adminis-
trators, and assigns, Her special licence that I, the said George Coburn
Wilson, my executors, administrators, and assigns, or such others as T, the
said George Coburn Wilson, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN METALLIC CARTRIDGE CASES," being a communication
to me from abroad by General Hiram Berdan, of the City of New York,
United States of America, but now resident at St. Petersburgh, in the
Empire of Russia, upon the condition (amongst others) that I, the said
George Coburn Wilson, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the
same to be filed in the Great Scal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said George Coburn Wilson, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement (that is to say) :-
In the Provisional Specification filed I have described, under what
is there termed the first part of my Invention, a solid head metallic
cartridge case which I am advised I cannot properly claim, and I there-
forc desire it to be understood that I disclaim so much of my Invention
as is there so described; and I will now proceed, by taking that part of
my Invention which is there described as being of the second part, and
which consists in forming a solid headed" cartridge case from one piece
of metal in such a manner as to produce an annular space around the
hub or exterior of the cap cavity in combination with a solid external
flange of a less thickness than the base of the cartridge case, and in
combination also with an external shoulder or boss of less diameter than
the flange, the said shoulder or boss being formed either at the front
or at the rear of the flange, or in both positions if necessary, so that
although the flange be not of itself sufficiently thick to fill the ordinary
recess or counterbore of a breech-loading rifle, yet the flange and the
shoulder or boss are sufficiently thick to do so.
.
Although one operation only is in some cases sufficient to form the
cap cavity and the solid external flange and shoulder, I prefer this to be
'done by two separate operations, because by so doing I obtain uniformity
in the thickness of the head of the cartridge case, notwithstanding
variation in the thickness of the metal employed, to a greater extent
than by any method of manufacture hitherto known. For in this
manner the cap cavity is formed in the first operation, and the thickness
of the head is precisely determined, the superfluous metal having room
to expand sideways in the counterbore of the dic. In the second
'operation the external flange is perfected, and any variation in the
thickness of the metal employed simply affects the thickness of the
external flange, which is a matter of small importance.
Another advantage obtained by the second part of my Invention is
that cartridge cases can be made of thinner metal than usual, and yet
they will possess very great strength. The use of thinner metal has
the advantage of reducing the strain upon the internal punch, and of
allowing the priming holes to be formed by punching through the metal

page_text: of the cap cavity instead of by the longer process of drilling, which is
necessary when thick metal is employed.
That my Invention may be fully understood I have annexed Drawings
thereof, which I now proceed to describe, and which will explain the
method of carrying my said Invention into effect. I will first proceed
to describe particularly the first five Figures, and in doing so I desire it
to be understood that the entire head of a cartridge case made according
to my Invention consists of those parts which in the several Figures
are included between the lines marked a, a, the distance from a to a
being equal to the depth of the counterbore of a breech-loading rifle;
and it will be also understood that the flange is that portion of the head
which is marked b, b, and which projects from the body part of the case,
and is used for the purpose of extracting the shell from the chamber in
the gun.
According to my Invention the entire head is made up of the flange b,
which is of a less thickness than the entire head, in combination with
a boss or shoulder c, which may be either in the front or in the rear of
the said flange, or in both positions if necessary, the said flange band
the boss or shoulder c together forming the entire head, so that the
cartridge case may be made from very much thinner metal than would
It
be required if the flange were as thick as the entire head a, a.
will be obvious that thinner metal than usual being employed the wear
of the dies and punches used in drawing the metal into shape will be
much less than if thicker metal were used.
ways
Figs. 1, 2, 3, 4, 5, and 9 shew a few only of a great variety of in
which, according to my Invention, a thin flange may be combined with
a boss or shoulder of any desired shape so as to form together the entire
licad of the cartridge case.
I will now proceed to describe Figs. 6, 7, 8, and 9. After the cartridge
case has been brought to the form shewn in Fig. 6 the entire head is
formed in two operations, the first of which is shewn in Fig. 7. d is the
die into which the cartridge case e is placed; fis the punch or bunter
which partially upsets the metal of the base of the cartridge case into
the recess or counterbore g of the die d, and determines precisely the
thickness of the entire head, the punch at the same time completing
the formation of the cap cavity 1. An internal punch formed to fit into
the annular recess of the cartridge case supports the latter during the
operation.

page_text: In the second operation the punch i (Fig. 8) is formed so as to produce
the flange b from a portion of the metal of the base without affecting
the thickness of the entire head which the previous operation had deter-
mined. An internal annular punch is used in this operation also in
order to support the cartridge case.
By this part of my Invention the said internal as well as the external
punch is greatly relieved from strain, for in the first operation a partial
upsetting only of the metal is performed, and in the second operation
the shoulder which was formed by the said partial upsetting transmits
to the die a great portion of the strain which would otherwise be
sustained by the internal punchi.
This part of my Invention also ensures accuracy in the thickness of
the entire head, for if there be any variation in the amount of metal in
the base of the cartridge case when in the form shewn in Fig. 6 the
thickness of the entire head is not affected thereby, because, in the first
operation (see Fig. 7) there is no restraint to the expansion of the metal
sideways in the counterbore of the dic, and, in the second operation (sec.
Fig. 8), the thickness of the flange alone is in question. Any variation
which may exist is thus thrown into the thickness of the flange, which
is an unimportant matter, provided the thickness of the entire head
is correctly maintained.
In Figs. 1, 2, 3, 4, and 5 the cap chamber is shewn in the form in
which the punch or bunter leaves it, that is to say, before the anvil has
been raised. In Fig. 9 the anvil m is shewn after having been raised by
a subsequent operation.
The use of thin metal, as herein-before described, also enables the vent
or priming holes to be formed by punching through the metal of the cap
cavity instead of by the longer process of drilling, which is necessary
when thick metal is employed.
Having now described the nature of my said Invention, and the
manner in which the same is to be performed, I desire it to be under-
stood that I do not confine myself to any or all of the particular forms
of flanges herein-before referred to and shewn in the several Figures,
because it will be obvious that, without departing from the nature of
my said Invention, an almost innumerable variety of forms of flanges
could be produced, all having for their object the reduction of metal in
the said flanges; but what I do claim as the Invention to be protected

page_text: by the herein-before in part recited Letters Patent is, the manufacture
of solid headed metallic cartridge cases in which the metal in the flange
is of a less thickness than the base or head of the casc, so that a less
quantity of metal is required than if the flange were as thick as the
entire base or lead, substantially as herein-before described and illus-
trated in the accompanying Drawings.
And I also desire to claim the manufacture of the said base or head
in two operations instead of one by the means herein-before described, so
as to relieve the punches employed from undue strain, and to obtain
greater accuracy in the thickness and in the diameter of the base or
head of the cartridge case, substantially as herein-before described.
In witness whereof, I, the said George Coburn Wilson, have here-
unto set my hand and seal, this Second day of January, in the
year of our Lord One thousand eight hundred and seventy-two.
Witness,
G. R. HOLLAND,
Patent Office,
Birmingham.
GEORGE C. WILSON. (L.S.)