Improvements in Cartridges for use with Projectiles containing High Explosives.
Year: 1898

page_text: Date of Application, 10th Oct., 1898-Accepted, 4th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in Cartridges for use with Projectiles containing High
Explosives.
I. JOHN PETER ELLIOT, residing in Block No. 67, Smith Street, Martinez,
Contra Costa County, State of California, U.S.A., Surveyor, 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:-
My invention relates to a device for the discharge of projectiles containing
high explosives, in such a manner that the initial impulse of the projectile will
not be accompanied by such a shock as will tend to explode the charge within
it before it leaves the gun.
It consists in a novel construction of the charge chamber of the cartridge and
its connection with the projectile and its chamber, and in details of construction
which will be more fully explained by reference to the accompanying drawings,
in which, Figure 1 is a longitudinal section shewing the union of the projectile
and the impelling charge in a cartridge, and the means for igniting the latter.
Figure 2 is a similar view shewing a converging powder chamber. Figure 3 is a
longitudinal section through of Fig. 4, shewing a central core with inde-
pendent surrounding powder chambers. Figure 4 is a transverse section
through of Fig. 3. Figure 5 is a similar section shewing a different form
for the powder chambers.
In order to impel projectiles containing high explosives it is necessary to
avoid the sudden initial shock which would be produced in the ordinary methods
of firing guns with charges of powder, this shock being so violent that it is very
probable it will discharge the high explosive at once and before the projectile
leaves the gun.
To avoid this is the object of my invention, and it is effected by forming a
cartridge containing the projectile and the impelling charge of powder in a
single structure, the area of the powder chamber or chambers being much less
than that of the projectile, and being extended to any desired length; and, if
desired, the powder chambers may be increased in diameter towards the rear
to give an accelerated motion to the projectile.
When made up as the cartridge the powder chamber, projectile and inter-
mediate cushion are all enclosed in an exterior shell to form a single structure.
The front end of the chamber B is concaved or made with a diminishing
bevel outwardly so as to form a space at the front for the expansion of a portion
of the powder charge which will thus occupy a diameter approximately as great
as the diameter of the projectile chamber.
The projectile D is made to fit the chamber which may be rifled, or the pro-
jectile may be in other ways guided so as to move accurately as it is discharged
from the gun.

page_text: The projectile is made hollow having a chamber D' which is adapted to con-
tain a high explosive, and it may be ignited by impact, by means of a percussion
cap or primer fixed at the front, or the cap or primer E may be fixed upon the
front end of a firing pin E which movable longitudinally within the projectile.
The forward momentum of the firing pin at the instant when the projectile
strikes and is arrested, will be sufficient to explode the cap and ignite the charge
within the shell.
The rear of the projectile is closed by a plug F.
A pin F extends to the rear from this plug.
Surrounding this pin or extension and having a diameter approximately the
same as that of the projectile so that it fits within the barrel of the gun, or
the cartridge case, is a cushion which is made of any suitable elastic material,
such as rubber, gutta percha, or a combination of these, and canvas or cloth
which may be made in a sheet and rolled up to the proper diameter to fit the
sheath and be interposed between the projectile and the powder charge. As
shewn in the present illustration, the cushion is formed with the end discs G
of rubber, and the central portion G¹ of woollen yarn, which will yield to com-
pression and also resist the destructive action of the ignited powder.
In order to ignite the powder charge in such a manner as to ensure the burning
of the whole charge with a gradually increasing force, I have shewn a firing pin
or rod H which extends through the centre of the cartridge to the front where
it makes contact with the projection F at the rear of the projectile.
The front end of this pin or rod is adapted to receive the cap or primer h, and
the rear end extending through the rear of the cartridge is so arranged as to
be struck by the hammer or other firing device, and when this is done the primer
at the front will be exploded. The gas from the cap or primer being discharged
rearwardly around the firing pin, will first ignite the powder in the front of
the powder chamber, and the first impulse to the projectile will be given at
this instant. The powder thence burning from front to rear, the increase of the
gases produced by the explosion will impel the projectile with an accelerated
motion until it is finally discharged from the gun and all of the powder within
the powder chamber will be burned without being thrown out of the gun as
might be the case if the ignition takes place from the rear.
The acceleration may be increased by gradually increasing the diameter of
the chamber from the front to the rear, the length being also increased as may be
desired.
In Figures 1 and 2, a single central powder chamber is shewn. In Figures 3,
4 and 5 the central portion is a solid core with a central longitudinal hole through
which the firing pin H is movable, and in place of a single powder chamber
there are a number of separate chambers 332 formed by longitudinal channels
made in the outside of the core, and by the enclosing exterior shell of the cart-
ridge. These essentially parallel chambers may gradually increase in area from
one end to the other as described for the single chamber, to provide for an
accelerating charge, and they unite at the front so that the single primer serves
to ignite the powder in all the chambers.
In order to still further reduce the initial velocity I prefer to employ a
powder of low force at the front of the powder chamber, the remaining portion
of the charge being of greater explosive force so that the weaker powder being
first ignited will start the projectile, and the impulse of the stronger powder
will then increase its velocity without the sudden shock which would otherwise
result.
The cushion G being interposed at the rear of the projectile, the first impulse
of the explosion is further cushioned upon this elastic block and the projectile
is thus started with the slowest possible initial velocity which is afterwards
rapidly increased to as high a velocity as may be desirable when it leaves the
muzzle of the gun.

page_text: The different diameters of the powder and projectile chamber of the cartridge
may be provided for by rolling paper around a mandrel which will give the
proper size for the single powder chamber B while the thickness of the paper
which forms the outside, as at B1, is sufficient to give it a diameter equal to that
of the projectile D.
The thickened cylinder or the chambered cores may be pressed out of paper
pulp or other light or suitable material, the whole being enclosed in the outer
shell J. The shell J may be made destructible at the junction of the projectile
with the cushion, or the cushion with the powder chamber, or at both portions.
The front end of the cartridge is cut away in a flat bevel inwardly at b, to
allow the powder within the chamber B to spread out into this portion and
beneath the elastic cushion G as previously described.
The rear end of the cartridge thus formed has fitted upon it a metal head I
flanged as shewn, to provide a hold for the shell extractor after the cartridge
has been fired. The cartridge is made up by placing the powder chamber B¹ in
contact with the rear of the elastic cushion G, this being connected with or
attached to the rear of the projectile D and the firing pin H extends through the
centre with its front end approximately in contact with the pin or extension F¹
at the rear of the projectile, and the whole is contained in the outer shell J
of the cartridge. This shell may be extended sufficiently to the front to enclose
the cushion and the rear part of the projectile and it may if desired be made
destructible at the junction with the projectile. The sheath or shell J may be
made of wrappings of paper sufficiently stout to hold the parts together, but
such as to be easily torn or destroyed at the instant the explosion takes place so
as to allow the proiectile to leave when the charge is ignited. This destructible
connection might, for instance, be made of paper suitably impregnated or other-
wise treated so as to be extra-inflammable.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:
•
1st. A cartridge of the type described, comprising a projectile and chamber,
one or more powder chambers of less area, a firing pin and means for igniting
the propelling charge at the front and a cushion interposed between the powder
chamber and the base of the projectile.
2nd. A cartridge consisting of one or more separate powder chambers of
small area with an exterior enclosing casing, a projectile of equal diameter with
the exterior of said casing, a cushion interposed between the base of the pro-
jectile and the front of the powder chamber, a pin extending rearwardly into
the centre of the cushion from the base of the projectile, a firing pin extending
centrally through the cartridge from the rear having the front end adapted
to receive an explosive cap or primer and abutting against the pin at the rear
of the projectile whereby the ignition of the powder in the chamber commences
at the front of the charge.
3rd. A cartridge comprising a projectile, a powder chamber having an
exterior diameter equal to that of the projectile and a small inner diameter to
receive the powder charge, a metallic head fixed to the rear of the powder
chamber having a hole made centrally in it, a firing pin extending through said
hole having the front end adapted to receive a primer or percussion cap, a pro-
jectile having a diameter equal to the exterior diameter of the powder chamber,
a pin extending rearwardly from the base of the projectile to contact with the
front end of the firing pin, an elastic cylindrical cushion interposed between
the projectile and the impelling charge, and an exterior shell enclosing the
powder chamber and the projectile, said shell being separable at the front of
the powder chamber when the cartridge is fired.
4th: In a cartride, a projectile chamber, a powder chamber of smaller diameter
and greater length than the projectile, a cushion interposed between the base

page_text: of the projectile and the impelling charge, a firing pin extending through the
chamber and a primer fitting the front end and explosible by percussion so as
to ignite and burn the powder charge from the front to the rear.
Dated this 10th day of October 1898.
for the Apрисали,
GEDGE & FEENY,
60, Queen Victoria Street, London, E.C., Chartered Patent Agents.