Year: 1886

page_text: I, THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster Civil·
Engineer do hereby declare the nature of this invention to be as follows:-
:―
The object of my invention is to provide a stronger and more durable cartridge case
than those hitherto used and one which can without too great cost of manufacture be
used for guns of considerably larger calibres than those at present provided with metal
cartridges.
I make the cartridge case in one piece of steel by drawing the metal by mechanical
means or I take a tube of steel drawn without weld or welded out of plate. I cut
off this tube to suitable lengths for the cartridge case. I fix to one end of each a base or
base plate made of gun metal, steel or iron the rim of which protrudes beyond the tube
for the purpose of extraction as usual. I fix the base or base plate by rivetting it to
one end of the tube or I fix the base or base plate on to the end of the tube by rivet
bolts with or without a washer or cup inside.
The other and foremost end of the tube is to be of suitable inside diameter for
holding the projectile, or it can be choked to a smaller diameter than the rest of the
tube if it is desired to have the portion of the cartridge case which contains the powder
of a larger diameter than is necessary for holding the projectile.
If it is required to have the cartridge case conical, a conical mandril can be driven
in from the base end before the base is affixed to the tube.
In order to fix the base which contains the chamber for the percussion cap, to the
stee tube, the rear end of the steel tube may be choked in so as partly to close the
rear, then the base is applied outside and a cup inside and these are fixed together to
the choked end of the tube by rivets. Or the rear end of the tube can be threaded
and the base prolonged forwards inside can be screwed into the tube. Or the rear end
of the tube can be bulged outwards the base inserted in the wider part and the end of
the tube again be choked in behind the base. Or the base can be made so that it-
enters in the shape of a shallow cup some distance inside the rear end of the tube
which is choked inwards so as partly to close up the rear of the tube, then when
the base is pushed in the cup shaped edges can be choked down over the end of the

page_text: tube turned inwards so as to hold the tube fixed to the base such choking of the cup
shaped base being done by means of a tool inserted through the front opening of the
tube. Or the part of the base which reaches some distance inwards can have a
recess or canelure made around it, into which after the base is inserted, the rear
end of the tube is driven, and then a ring of steel, iron or brass can be choked into
the recess outside the rear end of the tube so that this ring fills up the recess and
makes the outside form the same as the inside form of the chamber of the gun. Or
the recess can be so deep as to give room for the ring and still leave a rim for the
extractors to act upon without this fim protruding beyond the largest diameter of
the tube.
The advantages offered by thus making a cartridge case out of a steel tube with a
base or base plate fixed to it are many, for instance for large calibres where steel may
be more suitable than brass or gun metal for cartridge cases the steel cartridge cases
can be made in this manner much more cheaply than by drawing them solid in the
same way as is usually done with cartridge cases of brass or gun metal. The drawn or
rolled welded or weldless steel tube if tempered is so much stiffer than other metal
generally used for this purpose, that a cartridge case made as now proposed can be
reloaded many more times than can be done with ordinary cartridge cases; the
yielding and breaking strain and the elasticity of such steel tubes are so great that
more freedom can be given between the outside of the cartridge case and the inside of
the chamber of the gun-and for the same reasons a cartridge case made of a steel
tube can be made cylindrical or much less conical than has hitherto been customary
without causing difficulty in extracting it after being fired.
In consequence of the greater strength and elasticity of steel tubes the weight of
the cartridge case can be made much less than that of cartridge cases hitherto made
and the larger the calibre of the gun the more important is it to keep the cartridge
case as light as possible.

page_text: Improvements in Cartridges.
I, THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster,
Civil Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and by the
following statement :—
The object of my invention is to provide a stronger and more durable cartridge
case than those hitherto used and one which can without.too great cost of manufacture
be used for guns of considerably larger calibres than those at present provided 'with
metal cartridges.
I make the cartridge case in one piece of steel by drawing the metal by mechanical
means or I take a tube of steel drawn without weld or welded out of plate, I cut off
this tube to suitable lengths for the cartridge case and I fix as hereinafter described to
one end of each a base or base plate made of gun metal, steel or iron the rim of which
protrudes beyond the tube for the purpose of extraction as usual.
The advantages offered by thus making a cartridge case out of a steel tube with
a base or base plate fixed to it or formed in one piece with it are many.
The drawn or rolled welded or weldless steel tube if tempered is so much stiffer
than other metal generally used for this purpose that a cartridge case made as now
proposed can be reloaded many more times than can be done with ordinary cartridge
cases the yielding and breaking strain and the elasticity of such steel tubes are so
great that more freedom can be given between the outside of the cartridge case and
the inside of the chamber of the gun and for the same reasons a cartridge case made
of a steel tube can be made cylindrical or much less conical than has hitherto been
customary without causing difficulty in extracting it after being fired.
In consequence of the greater strength and elasticity of steel tubes the weight of
the cartridge case can be made much less than of cartridge cases hitherto made and
the larger the calibre of the gun the more important is it to keep the cartridge case
as light as possible.
The drawings hereunto annexed shew examples of cartridge cases for guns of large
calibre formed of steel as above described.
The cartridge case shewn in longitudinal section at Figure 1 is formed in one piece
of steel. It is made from a disc forced in succession through a series of dies con-
tinually decreasing in internal diameter. The disc is forced through the dies on a
mandril.
For the first few reductions sometimes it is heated prior to being forced through.
the dies but when the sides of the tube have become comparatively thin the remaining
reductions are made without reheating the metal. When the case has been drawn
down to the diameter required the tube is cut to the proper length--the rim is formed
around the end of the base by pressing the metal out or in other suitable way and if
required the open end of the case is choked in as shewn to make it of a diameter
suitable for receiving the base of the projectile. A central hole is also bored in the
base of the cartridge case and a firing tube screwed into it as shewn or fixed in any
other suitable way.
Figure 2 is a longitudinal section of a steel cartridge case formed in the manner I
prefer when the tube is in a separate piece from the base. The end of the steel tube
which is to have the base, secured to it is choked in to the formn shewn-the base is
made of two main parts-one a ring A cup shaped on one face for the choked in end
of the tube to fit into the other B which is put in from the opposite end of the tube

page_text: is formed so that it covers the whole of the inside base of the cartridge-its outer
part is cup shaped to fit into the interior of the choked in end of the tube-at the
centre it has a cylinder projecting backwards from it which passes through the ring A
and is rivetted or choked over as shown. A brass or copper cup shaped ring C, is
preferably put between the parts A and B as shown to form a gas check and make
the base of the cartridge gas tight.
A central hole is formed through the part B for a firing tube D to be screwed into
as shewn.
In place of the parts A and B being held together by forming the part B with a
rivet stem of large diameter to pass through A and be rivetted over the parts, A and
B might be held together by separate rivets E as shewn at Figure 3. I however
prefer the first plan shewn at Figure 2.
Other ways than those above described may be adopted for securing the base into
the end of the steel tube. For example the rear end of the tube can be threaded and
the base prolonged forwards inside can be screwed into the tube. Or the rear end
of the tube can be bulged outwards the base inserted in the wider part and the end
of the tube again be choked in behind the base. Or the base can be made so that it
enters in the shape of a shallow cup some distance inside the rear end of the tube
which is choked inwards so as partly to close up the rear of the tube, then when the
base is pushed in the cup shaped edges can be choked down over the end of the tube
turned inwards so as to hold the tube fixed to the base such choking of the cup shaped
base being done by means of a tool inserted through the front opening of the tube.
Or the part of the base which reaches some distance inwards can have a recess or
cannelure made around it, into which after the base is inserted, the rear end of the
tube is driven, and then a ring of steel, iron or brass can be choked into the recess
outside the rear end of the tube so that this ring fills up the recess and makes the
outside form the same as the inside form of the chamber of the gun. Or the recess
can be so deep as to give room for the ring and still leave a rim for the extractors to
act upon without this rim protruding beyond the largest diameter of the tube.
The foremost end of the cartridge cases can be choked to a smaller diameter than
the rest of the tube if it is desired to have the portion of cartridge case which contains
the powder of a larger diameter than is necessary for holding the projectile.
If it is required to have the cartridge case conical a conical mandril can be driven
in from the base end before the base is affixed to the tube.
In some cases I not only form the cartridge cases of steel but in addition I temper
the steel in order to increase its elasticity and the yielding and breaking strain-so
that the cartridge cases may be reloaded a greater number of times and as before
stated more freedom given between the outside of the cartridge case and the inside of
the chamber of the gun.
The process of tempering takes place when the cartridge case has been fully drawn
to near the proper dimensions and before it is turned and polished in order to make it
of the exact dimensions wanted.
Having now particularly described and ascertained the nature. of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. A cartridge case for guns of large calibre with the sides formed of steel tube.
2. A cartridge case formed in one piece of steel substantially as described.
3. A cartridge case having its sides formed of tempered steel tube substantially as
described.
4. A cartridge case formed substantially as described with reference to figures 2
and 3.
Dated this 24th day of February 1887.