Improvements in Gas Checks for Projectiles.
Year: 1895

page_text: Date of Application, 26th June, 1895
Complete Specification Left, 12th Mar., 1896-Accepted, 18th Apr., 1895
PROVISIONAL SPECIFICATION.
Improvements in Gas Checks for Projectiles.
I ALFRED NOBEL of 59 Avenue Malakoff, Paris in the Republic of France,
Chemist, do hereby declare the nature of this invention to be as follows:-
Projectiles are usually provided with driving rings of copper or other soft metal,
which, on being squeezed into the rifle grooves of a gun, act also as gas checks.
Such provision for gas checking has, however, been found inadequate to check
all leakage of gas, and prevent erosion in the bore of guns, consequent on such.
leakage. The gas check rings which constitute the subject of the present:
invention are so devised as to cause a rapid expansion of said rings sufficient to
prevent leakage of gas. Various devices may be employed to secure this effect,
gases of explosion being in all cases used to drive in a radial direction the gas
check ring against the bore of the gun.
The projectile may be formed with an annular groove near its base to receive
a check ring of copper or other metal, which will take such shape or proportions
with respect to the groove, as to form behind it a closed annular chamber for
the reception of the explosive material. This chamber will be open to the rear
of the projectile by means of a channel which is closed by a hollow plug fitted.
with a loose valve capable of yielding to end pressure. A cord or thread of
ballastite may conveniently form the explosive used in filling the chamber, such
coid being so proportioned as to ensure, when ignited, the requisite internal
pressure on the check ring. The cord thread may extend down the channel,
and through the hollow plug carrying the valve.
When, therefore, the charge is fired, the fire will be communicated to the
explosive material in the chamber, and an instant radial expansion of the check
ring will take place.
Instead of placing ring expanding material in the annular chamber, the base
of the projectile may be pierced to form a chamber or chambers for the explosive.
compound, such chambers communicating by channels with the annular chamber,.
for the purpose of delivering the gases evolved to the back of the check ring.
These chambers in the base of the projectile will be closed by perforated plugs,
as above explained. Or, in place of leading the compressed gases to the check:
ring, the annular chamber may be charged with a semi-liquid substance for
receiving the pressure of the gases and transmitting the same to the check ring.
In place of forming an annular chamber between the projectile and the check.
ring, the so-called check ring may form the base of the projectile, and be screwed,
onto a central stem thereof, when it will act as a driving ring. In this case, the
chamber for receiving the charge for expanding the ring will be formed in the
ring itself, and be open to the base of the projectile.
In some cases, it may be found desirable to dispense with the charge used for
expanding the ring, and to rely on the gases evolved from the firing charge of
the gun driving forward an expanding wedge fitted in the annular chamber of
the ring, and thus imparting the radial pressure to the ring, to secure a close,
gas check.
Dated this 26th day of June 1895.
NEWTON & SON,
Agents for the Applicant.

page_text: provements in Gas Onecks for Projecules.
I ALFRED NOBEL of 59 Avenue Malakoff, Paris, in the Republic of France,
Chemist, 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 :-
Projectiles are usually provided with a driving ring of copper or other soft
metal, which, on being squeezed into the rifle grooves of a gun, acts also as a gas
check. Such provision for gas checking has, however, been found inadequate to
check all leakage of gas, and prevent erosion in the bore of guns consequent on
such leakage.
Now the object of this invention is to obtain a gas check ring which will expand
rapidly when the charge is fired, so as to prevent leakage of gas. Various devices
may be employed to secure this effect, gases of explosion being in all cases used to
expand in a radial direction the gas check ring, that it may fit tightly the bore of
the gun.
Fig. 1 in the accompanying drawing shows in partial central section a projectile
constructed to receive, according to this invention, an expanding ring or gas
check.
A is the projectile, a a driving and gas checking ring of copper, aluminium,
brass, or other soft and resisting metal; 6 is a groove in the ring a, but said groove
may be replaced by a corresponding groove in the projectile, as indicated by the
dotted lines b; or the projectile as well as the ring may be grooved, to form an
annular chamber behind the ring. c is a small outlet leading from the groove b to
the rear of the projectile. d is a screw, which partly bars the opening c, leaving,
in its centre, the touch hole e. f is a small valve, which may be conical or
spherical, and which an excess of interior pressure automatically shuts.
The aforesaid gas check operates as follows:-The groove b receives a charge
of very quick powder, which is introduced through the opening c, which opening is
then partially closed by the hollow screw d. The powder charge should be so
regulated by aid of well-known tables of powder pressure, as to obtain, as near as
possible, the pressure aimed at, which is sufficient to swell the ring a, and thereby
secure immediate gas checking, without too violent action on the bore of the gun.
A very convenient explosive for charging said groove or chamber is the one
described in the British Patent dated January 31st 1888, No. 1471, and known as
"ballistite." It is easily made into cords of any size, and of such porosity as to act
as an instantaneous fuse, and secure an extremely quick explosion. By duly
proportioning the thickness of said string to the size of the chamber, so as to leave
sufficient air cushioning, overpressure is avoided. Through the inlet c, the
ballistite may easily be inserted into the chamber b, and if it is allowed to reach or
outreach the touch-hole it will readily ignite when the main charge of the gun
Instead of the ballistite cord, other quick explosives may be used, but the
charging will possibly be less convenient, and the pressure tend to be somewhat
more localised.
is fired.
e,
By firing the main charge near to the touch-hole e, the gas checking action of
the aforesaid ring can be accelerated ;-and, to render it still more instantaneous,
electric firing might be effected in the touch-hole e, so as to ignite the special gas
checking charge herein described, and relying on that charge to fire the main
charge of the gun. But experiments hitherto made have not appeared to show the
necessity for resorting to such complication.
The small valve f is intended to shut off automatically the communication

page_text: but
between the main powder chamber and the small gas checking chamber, whenever
the pressure in the latter is in excess. The gas thus completely confined, keeps up.
its pressure tolerably well during the passage of the projectile through the entire
length of the bore, and thus tends to act as a gas check not only in the rear,
throughout the whole length of the gun. Unless such prolonged gas checking is
needed, said valve can be dispensed with. Its presence necessitates making the
gas check ring very resiting, in order to prevent its bursting when the projectile
leaves the gun.
As soon as the main charge of the gun is fired, the ignition spreads inside the
touch-hole e, and catches the charge in the chamber b, which charge, by the strong
pressure produced, expands the ring a, and forms therewith a perfect gas check.
The expansion is momentary, and can only be measured by its effect in preventing
erosion.
Fig. 2 shows in partial section a modified form of the projectile for receiving the
expanding ring. a is the gas check or driving ring, 6 the groove or chamber
already described, e one or more powder chambers, each communicating through
an opening d with the groove b; e is a hollow screw partially closing the powder
chamber c; f is a touch-hole, and g the valve already described.
As soon as the charges in the chambers c have been fired through the touch-
holes f, the gas produced enters through the inlets d into the groove b, and swells
by its pressure the ring a.
In Fig. 3, the arrangement only so far differs from what is shown in Fig. 2, as
that the groove b is filled with water, or some viscous or soft substance, such as
soft glue or vaseline, which transmits to the ring a the pressure developed by
exploded powder in the chambers c. A small inlet q is provided for conveniently
filling the annular groove b with the aforesaid liquid, viscous, or soft material, and
is then closed by a screw or plug h. i is a small plug or partition which the
powder gas blasts or removes, and which serves the purpose of separating the
powder charge from the liquid or other viscous or soft substance contained in.
the groove b, which liquid or equivalent substance transmits the pressure of the
powder gas, and somewhat accelerates the swelling out of the aforesaid ring a.
Fig. shows an arrangement which somewhat differs from those heretofore
described. A is a hollow or chambered ring made to contain a powder charge of
the volumetric density needed to effect, when ignited, the éxpansion of said ring
requisite to make it act as a perfect gas check. Said ring should be well secured
on the projectile, or otherwise fixed. is a touch-hole through which the fire from
the main charge is allowed to enter into the chambered ring a, and through which
said chamber may also receive its powder charge..
It is not absolutely necessary that the ring A should be closed on all sides. It
may be shaped, as shown in Fig. 5, with a kind of groove or chamber, charged
with some very quick explosive, such as highly nitrated paper, and presenting all
round a slit, open to the main charge, and through which the inside charge will be
fired. Said contrivance can only act quickly enough for the purpose herein set.
forth if the aforesaid slit is very narrow, and the inside charge very quick.
The gas checking rings herein described may be made to serve as driving rings
as well, or projectiles may be provided with the usual driving rings in conjunction
with gas-check rings, such as herein described.
It is clear that the construction of the aforesaid gas-checking rings may be
greatly varied, without departing from their distinctive feature, which consists in
causing them to expand radially so rapidly as to realize very perfect gas checking,
and thereby prevent or greatly reduce erosion in guns.
Having now particularly described and ascertained the nature of my said inven- .
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A projectile fitted with a gas check ring or rings, which, by the explosion of
a special charge, located in the projectile, or in the ring or rings, and fired by the

page_text: main charge or otherwise, is pressed in a radial direction against the bore of the
gun, substantially as herein shown and described.
2. In projectiles of the character referred to in the first claim,
a) The arrangement of a valve which the special charge above referred to,
when fired, automatically shuts, for the purpose of keeping up the pressure
produced, as and for the purpose above set forth;
b) The means provided for receiving the special charge. referred to in Claim 1,
as herein shown aud described.
Dated this 11th day of March 1906
NEWTON & SON,
Agents for the Applicant.