Improvements in the Manufacture of Metallic Cartridge Cases.
Year: 1893

page_text: Date of Application, 4th Apr., 1893
Complete Specification Left, 4th Jan., 1894-Accepted, 10th Feb., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Metallic Cartridge Cases.
I, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redferu & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication to
me by Ernst Ternström, of 8, Rue Auber, Paris, in the Republic of France,
Engineer) to be as follows:-
This invention relates to the manufacture of metallic cartridge-cases and has for
its object to make them of less weight and less costly than the solid drawn
cartridge-cases hitherto used.
The new cartridge-case constructed according to this invention consists of three
component parts, viz.,-the body, the base-cup and the keeper-ring or disc.
The body is made of brass, tinned iron or other suitable metal and can be either
a solid drawn tube or made of a coiled up overlapping metal sheet to fit the
chamber of the gun. Both its ends are open before the parts are put together, and
its rear end is worked to suitable dimensions for entering the base-cup. Bodies
constructed in this manner can be made much thinner and lighter than when drawn
out from the bases as in solid drawn cartridge-cases.
The base-cup can be made of malleable cast-iron or of wrought iron or other
suitable metal which is not necessarily capable of being drawn out into a body.
This base-cup which is provided with a flange or groove for extraction and with a
recess for the percussion cap, or with the usual arrangement for electrical firing is
tapered upwards and is provided round its inner surface with a groove or recess
into which the body is driven by the keeper-ring.
The keeper-ring is made of wrought iron or mild steel or other metal
sufficiently stiff to hold the body in its place and sufficiently ductile not to crack
when stretched.
Sometimes I use a buckled keeper-disc in preference to the keeper-ring.
In cases where special lightness is important I make the three component parts
of aluminium alloy.
In assembling the three component parts into a complete cartridge-case, the
base-cup is placed inside a mould to secure it against deformation and the rear end
of the body is inserted into it; the keeper-ring is then placed on the base inside
the body and a punch is inserted through the mouth of the body until its lower end
touches the keeper-ring, the said lower end of the punch being bevelled, rounded or
shaped to the form which I wish to give to the keeper-ring when the cartridge-case
is ready. When pressure is put on the punch the keeper-ring is extended in
diameter and forces the body into the groove or recess inside the base-cup and holds
it there as firmly as can be desired.
When a buckled disc is preferred the punch flattens it, thus increasing its
diameter and shaping it as desired. The disc is provided with a hole in its
centre large enough to prevent it from bearing against the pan which contains the
percussion or electrical cap so that the latter can not be deformed when the disc is
Alattened out.
In the improved cartridge-cases no rivets are required for securing the body to
the base-cup and the parts made of iron can be tinned, varnished or otherwise
treated so as to prevent any corrosion.
I am aware that other cases have been invented and used where a body has been

page_text: fixed to a base, but I have found none so reliable and convenient as the one now
described, especially for arms with calibres larger than rifle calibres.
When large cartridge-cases containing powder have to be fixed to heavy
projectiles, it has been found difficult to fix them rigidly together; I do this by
running a wire of copper or other metal round the neck of the case where it is
pressed into the groove usually cut in the projectile, and I twist the ends of the
wire firmly together and flatten them into a longitudinal groove. When extracting
the fixed cartridge-case, the wire remains embedded in the neck, and the mouth of
the cartridge-case is not torn off when the rear edge of the groove in the projectile
is well rounded off.
Dated this 4th day of April 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Metallio Cartridge Cases.
İ, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication to
me by Ernst Ternström, of 8, Rue Auber, Paris, in the Republic of France,
Engineer) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to the manufacture of metallic cartridge-cases of the kind
in which the body and the base are made separately and secured together, the
object of the invention being to secure the body to the base more efficiently than
heretofore so that the case will not be injured by the explosion within it or by the
extraction of the case after firing, thereby enabling it to be used again and again.
The new cartridge-case constructed according to this invention consists of three.
component parts, viz.,-the body, the base-cup and a keeper-ring which is forcibly
expanded to press a part of the body into a cannelure or groove formed inside the
upright cylindrical part of the base-cup.
To enable the said invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which:-
:-
Figure 1 is a longitudinal section of a cartridge-case manufactured according to
the said invention:
Figures 2 and 3 are sectional views of keeper-rings which can be employed.;
and,
Figure 4 is a sectional view of the cartridge-case shewing the parts assembled.
ready for fixing and the punch by which the expansion of the ring is effected.
a is the body of the metallic cartridge-case, and b is the base-cup the upright
wall of which is made tapering near the top as at c and provided with a cannelure
or grooved near the bottom so as to form a projecting ledge or rim.e.
The body a is made of brass, tinned iron or other suitable metal and can be.
either a solid drawn tube or made of a coiled-up overlapping metal sheet to fit the
chamber of the gun. Both its ends are open before the parts are put together,
and its rear end is worked to suitable dimensions for entering the base-cup.
The base-cup 6 can be made of malleable cast-iron or of wrought iron or other
suitable metal which is not necessarily capable of being drawn out into a body.
This base-cup is provided with a flange (or groove) for extraction and with a
recess 9 for the percussion cap, or with the usual arrangement for electrical
firing.
his the keeper-ring which is made of wrought iron or mild steel or other metal
sufficiently stiff to hold the body in its place and sufficiently ductile not to crack
when stretched or expanded,

page_text: In assembling the three component parts into a complete cartridge-case, the
base-cup b is placed inside a mould to secure it against 'deformation and the rear
or lower end of the body a, which is shaped as shewn in Figure 4 to fit the taper
portion of the base-cup, is inserted into it; the keeper-ring is then placed on the
base inside the body and a punch i, also shewn in Figure 4, is inserted through the
mouth of the body until its lower end touches the keeper-ring, the said lower
end of the punch being bevelled, rounded or shaped to the form which it is wished
to give to the keeper-ring. When pressure is put on the punch the keeper-ring is
extended in diameter and forces the body a into the canuelure or groove d inside
the base-cup and holds it there as firmly as can be desired.
:J.
The keeper-ring can also be extended in diameter, and thus fix the body in the
cannelure below-the projecting ledge by being. spun into it from the inside by
rollers, the shape of which also determines the form of the inner surface of the
ring when operated upon.
Some of the advantages of the said invention are that it offers an efficient
method, without the use of rivets or screws, of rigidly joining a body to a base,
thus meeting the important essential requirement for high pressure, viz., of allowing
the base to be made of a very stiff and strong metal which has less tendency to
bulge than the softer metal required for drawing into solid cartridge-cases, while
the body or tube can be made of a softer metal which has no tendency to crack
or rend; that the keeper-ring reinforces and strengthens the weakest part of the
cartridge-case, viz., the corner where the body is joined to the base the only part
where the cartridge-case is not supported by the chamber of the gun or by the
breech-block; that the keeper-ring is pressed radially outwards by the powder-
pressure on the explosion of the charge, the joint being thereby made firmer and
more rigid after every round fired, which adds to the durability of the cartridge
during repeated use; and that it is specially suitable for cartridge-cases of light
weight made of aluminium or aluminium bronze, which can be successfully stamped
into base-cups and keeper-rings and rolled into sheets, but which it is almost
impossible to draw into tubes or solid cartridge-cases especially for larger calibre
guns.
In the improved cartridge-cases the parts made of iron can be tinned, varnished
or otherwise treated so as to prevent any corrosion.
When large cartridge-cases containing powder have to be fixed to heavy
projectiles, it has been found difficult to fix them rigidly together; I do this by
running a wire of copper or other metal round the neck of the case where it is
pressed into the groove usually cut in the projectile, and I twist the ends of the
wire firmly together and flatten them into a longitudinal groove. When extracting
the fired cartridge-case, the wire remains embedded in the neck, and the mouth of
the cartridge-case is not torn off when the rear edge of the groove in the projectile
is well rounded off.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I wish it understood I
am aware it has been proposed to secure the bodies of composite cartridges to
their bases by means of discs, washers or cups but the constructions proposed
required the use of an unnecessary amount of metal and I do not claim such as my
invention but what I do claim is :-
1. A composite cartridge case, the body or tube of which is joined or fixed
to the base-cup by pressing one end of the body into a cannelure or groove formed
around the inside of the upright cylindrical part of the said base-cup by means of
a ring expanded by means of internal pressure, substantially as described.
2. In the manufacture of a composite cartridge-case of the kind referred to in
the preceding claiming clause, the extension of the diameter of the keeper-ring by
means of a punch with bevelled outer edges the stroke of which acts upon the
inner surface of the ring and causes the ring to drive one end of the body into the
cannelure or below the projecting ledge, for the purpose described.

page_text: 3. In the manufacture of a composite cartridge case of the kind referred to in
Claim 1 the extension of the diameter of the keeper-ring for the purposes specified
by means of rollers acting upon the inner surface of the keeper-ring, substantially
as described.
4. The manufacture and use of metallic cartridge-cases, substantially as herein-
before described and illustrated in the accompanying drawing.
Dated the 4th day of January 1894.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.