Improvements in Explosive Projectiles.
Year: 1896

page_text: Date of Application, 1st Dec., 1896
Complete Specification Left, 26th Aug., 1897-Accepted, 16th Oct., 1897
PROVISIONAL SPECIFICATION.
Improvements in Explosive Projectiles.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (which has been communicated to me from abroad by James King
Bakewell, Attorney at Law, of Pittsburgh in the County of Allegheny and State
of Pennsylvania, one of the United States of America) to be as follows:-
This invention relates to a construction of and mode of dealing with explosive
projectiles or shells such that nitro-glycerine, dynamite, and other powerful
explosives may be safely employed as explosive agents.
The use of dynamite as a charge for explosive projectiles has hitherto been
considered too dangerous to be employed in an ordinary gun, from which the shell
is ejected by explosion of gun powder, and, therefore appliances such as pneumatic
guns have been devised for this purpose, but these are more or less objectionable
in practical use. The object of this invention is to produce a shell charged with
dynamite or other powerful explosive, which may be fired by gunpowder from an
ordinary gun, without danger of premature explosion of the shell. The invention
consists broadly in charging the shell with nitro-glycerine, dynamite, or other
powerful explosive, and in reducing the temperature of the explosive agent to
such a degree that it may be fired without danger of explosion from the shock
produced by the discharge, the explosive in the shell being afterwards brought
into condition for explosion, either by the heat generated by impact of the pro-
jectile against the target, or by supplemental heat generated in the projectile by
a combustible, such as a slow burning powder or fuse, or by other heat-producing
agent.
The fact that nitro-glycerine and its compounds are of such high explosive
character that they readily explode on being subjected to concussion has rendered
them hitherto unsafe to be used in guns. Hitherto, also, frozen nitro-glycerine
has been regarded as practically incapable of explosion.
Recognising these facts my correspondent saw that it was necessary, in order to
utilize these high explosives for ordnance purposes, first to reduce them to a non-
explosive temperature before firing, and, secondly, to render them explosive after
firing. Both of these necessary conditions are secured by freezing the explosive
before firing the 'shell and afterward heating it either by a heat-producing agent,
or solely by the rapid passage of the projectile through the atmosphere and from
the gun, and by the great heat produced by its impact on an object which it
strikes.
It has been discovered by experiment that when dynamite is cooled down to
40° F., or to a lower temperature, it can be used as an explosive agent in projectiles
without danger of its being exploded by the firing of the gun, and the same is
true of nitro-glycerine and its compounds, and although it is not desired to limit
this invention to the use of any particular form of shell, in the accompanying
drawings a convenient form of shell adapted to this purpose is shewn.

page_text: Figure 1 shews in vertical axial section an armour piercing shell constructed
in accordance with my invention, and having a fuse and detonating cap to ensure
explosion of the charge. Figure 2 is a like section, showing a service projectile
with a firing pin. Figure 3 is a like section of a service projectile, having a time
fuse, a heating agent for heating the frozen explosive, and a detonating cap.
Figure 4 is a vertical axial section of the case for containing the frozen
explosive.
In Figure 1, 2 is the body of the projectile having a cavity for the explosive
opening at the rear. The explosive charge, which is preferably dynamite (but
which may be liquid nitro-glycerine, or other high explosive which is rendered
non-explosive by freezing) is put in a metal case 3, fitting the cavity. This
charged case is introduced into the projectile, preferably after the explosive has
been frozen; by putting the charged case into any suitable refrigerating chamber.
A charge of gunpowder 4 is then inserted and the rear end of the cavity is closed
by a plug 5 containing a time fuse 6 having at its end a detonating cap 7. 8, 8 are
vent-holes leading from the cavity of the projectile for venting it when the
powder 4 is ignited. The parts of the projectile having been thus put together
the explosive in the case being frozen, the projectile can be fired from the gun
at once, or may be kept ready as long as desired by storing it in a refrigerator.
Instead of freezing the explosive before putting it into the projectile, it may be
first put into the projectile and then frozen by placing the projectile in the
refrigerator.
The projectile is fired by a suitable charge of gun powder or other propelling
agent leaving the gun safely, and the time-fuse 6 being ignited. When the
projectile strikes an object, the heat generated, if the object is an armour plate
and if the cooling of the explosive has not been carried much below its freezing
point suffices to thaw the explosive so that it is exploded by the concussion. The
time-fuse and detonating cap are therefore in such a case unnecessary, but I prefer
to employ them for ensuring the explosion even after the projectile has penetrated
the object.
When the fuse is burned to the end, which may be after the projectile has
entered the object, the powder 4 is ignited and the detonating cap 7 is exploded,
and by their conjoint action the thawing and explosion of the explosive are
effected. When the explosion is intended to be thus effected after impact, the
explosive should in the first instance be cooled considerably below the freezing
point, so that the impact alone may not be sufficient to thaw and explode it. For
an armour piercing shell, having the cap and fuse, the powder 4 may be omitted,
the fuse being alone relied upon to furnish such heat as may be required to
supplement that generated by impact.
In Figure 3, I show a service shell which may be used not only for firing against
armor plate, but against earth works, etc., where the heat of impact has to be
supplemented by additional heat followed by detonation to supplement or take
the place of the action of the impact. In this case. where the shell is not to be
used for piercing armour the cavity and the case 3 may be made of large dimen-
sions. A body of powder 4 or other heat-giving agent is placed behind the cap 7,
so that it is ignited before the cap is exploded. The powder 4 may be arranged
to surround the case 3, or otherwise brought into more intimate contact with it.
When this projectile is fired the fuse 6 ignites the powder 4, heats the case 3,
and fires the cap which explodes the compound in the case 3. By regulating
the length of the fuse and the quantity and rate of burning of the powder 4, the
time when the explosive is sufficiently heated may be accurately determined, and
by employing a sufficient quantity of powder 4 and a suitable time-fuse and cap,
the projectile may be adapted to be exploded during its flight.
When the object fired at is an armour plate, or like hard substance, the pro-
jectile may be exploded by impact alone without detonating cap or supplemental
heating agent. I prefer, however, to intensify the heating action of the impact
in such case by employing a firing pin 9, as shown in Figure 2, which extends

page_text: from the point of the projectile into the cavity thereof and may have at its rear
end an enlarged head or piston 10. When the projectile strikes the firing pin
and its head are forced in so as to compress the explosive thereby heating and
exploding it.
Although it is known that dynamite and nitro-glycerine are rendered difficult
to explode by cooling them below 40° F., I am not aware that any practical use.
has been made of this knowledge, or that it is known that while frozen nitro-
glycerine is practically non-explosive in a gun when it is used to charge projectiles,
it can be heated and exploded after being fired from the gun. The freezing of
nitro-glycerine has practically been avoided owing to its non-explosive properties
while in that condition, and the danger of accidental explosion in case of its being
thawed by artificial means.
It is to be understood that my invention is not only applicable to nitro-glycerine
or its compounds, such as dynamite, but also to other high explosives which can
be rendered less explosive by cold and that the charge may be introduced into the
cavity of the projectile without a case enclosing it.
Dated this First day of December 1896
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Explosive Projectiles.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (which has been communicated to me from abroad by James King
Bakewell, Attorney at Law, of Pittsburgh in the County of Allegheny and State
of Pennsylvania, one of the United States of America) 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 a construction of and mode of dealing with explosive
projectiles or shells such that nitro-glycerine, dynamite, and other powerful
explosives may be safely employed as explosive agents.
The use of dynamite as a charge for explosive projectiles has hitherto been
considered too dangerous to be employed in an ordinary gun, from which the shell
is ejected by explosion of gun powder, and, therefore appliances such as pneumatic
guns have been devised for this purpose, but these are more or less objectionable
in practical use. The object of this invention is to produce a shell charged with
dynamite or other powerful explosive, which may be fired by gunpowder from an
ordinary gun, without danger of premature explosion of the shell. The invention
consists broadly in charging the shell with nitro-glycerine, dynamite, or other
powerful explosive, and in reducing the temperature of the explosive agent to
such a degree that it may be fired without danger of explosion from the shock
produced by the discharge, the explosive in the shell being afterwards brought
into condition for explosion either by the heat generated by impact of the pro-
jectile against the target, or by supplemental heat generated in the projectile by
a combustible, such as a slow burning powder or fuse, or by other heat-producing
agent.
The fact that nitro-glycerine and its compounds are of such high explosive
character that they readily explode on being subjected to concussion has rendered
them hitherto unsafe to be used in guns. Hitherto, also, frozen nitro-glycerine
has been regarded as practically incapable of explosion,

page_text: Recognising these facts, my correspondent saw that it was necessary, in order
to utilize these high explosives for ordnance purposes, first to reduce them to a
non-explosive temperature before firing and, secondly, to render them explosive
after firing. Both of these necessary conditions are secured by freezing the
explosive before firing the shell and afterwards heating it either by a heat-
producing agent, or solely by the rapid passage of the projectile through the
atmosphere and from the gun, and by the great heat produced by its impact on
an object which it strikes.
It has been discovered by experiment that when dynamite is cooled down to
40° F., or to a lower temperature, it can be used as an explosive agent in projectiles
without danger of its being exploded by the firing of the gun, and the same is
true of nitro-glycerine and its compounds, and although it is not desired to limit
this invention to the use of any particular form of shell, in the drawings accom-
panying the Provisional Specification a convenient form of shell adapted to this
purpose is shewn.
Figure 1 shews in vertical axial section an armour piercing shell constructed
in accordance with this invention, and having a fuse and detonating cap to ensure
explosion of the charge. Figure 2 is a like section, shewing a service projectile
with a firing pin. Figure 3 is a like section of a service projectile having a time
fuse, a heating agent for heating the frozen explosive, and a detonating cap.
Figure 4 is a vertical axial section of the case for containing the frozen explosive.
In Figure 1, 2 is the body of the projectile having a cavity for the explosive
opening at the rear. The explosive charge, which is preferably dynamite (but
which may be liquid nitro-glycerine, or other high explosive which is rendered
non-explosive by freezing) is put in a metal case 3, fitting the cavity. This
charged case is introduced into the projectile, preferably after the explosive has
been frozen; by putting the charged case into any suitable refrigerating chamber.
A charge of gunpowder 4 is then inserted and the rear end of the cavity is closed
by a plug 5 containing a time fuse 6 having at its end a detonating cap 7. 8, 8
are vent-holes leading from the cavity of the projectile for venting it when the
powder 4 is ignited. The parts of the projectile having been thus put together
the explosive in the case being frozen, the projectile can be fired from the gun at
once, or may be kept ready as long as desired by storing it in a refrigerator.
Instead of freezing the explosive before putting it into the projectile, it may be
first put into the projectile and then frozen by placing the projectile in the
refrigerator.
The projectile is fired by à suitable charge of gun powder or other propelling
agent leaving the gun safely, and the time-fuse 6 being ignited. When the pro-
jectile strikes an object, the heat generated, if the object is an armour plate and
if the cooling of the explosive has not been carried much below its freezing point
suffices to thaw the explosive so that it is exploded by the concussion. The time-
fuse and detonating cap are therefore in such a case unnecessary, but I prefer to
employ them for ensuring the explosion even after the projectile has penetrated
the object.
When the fuse is burned to the end, which may be after the projectile has
entered the object, the powder 4 is ignited and the detonating cap 7 is exploded,
and by their conjoint action the thawing and explosion of the explosive are
effected. When the explosion is intended to be thus effected after impact, the
explosive should in the first instance be cooled considerably below the freezing
point, so that the impact alone may not be sufficient to thaw and explode it.
For an armour piercing shell, having the cap and fuse, the powder, 4 may be
omitted, the fuse being alone relied upon to furnish such heat as may be required
to supplement that generated by impact.
In Figure 3, is shewn a service shell which may be used not only for firing
against armour plate, but against earth works, etc., where the heat of impact has
to be supplemented by additional heat followed by detonation to supplement or
take the place of the action of the impact. In this case where the shell is not to

page_text: be used for piercing armour, the cavity and the case 3 may be made of large
dimensions. A body of powder 4 or other heat-giving agent is placed behind
the cap 7, so that it is ignited before the cap is exploded. The powder 4 may be
arranged to surround the case 3, or otherwise brought into more intimate contact
with it. When this projectile is fired the fuse 6 ignites the powder 4, heats the
case 3, and fires the cap which explodes the compound in the case 3. By regu-
lating the length of the fuse and the quantity and rate of burning of the powder 4
the time when the explosive is sufficiently heated may be accurately determined,
and by employing a sufficient quantity of powder 4 and a suitable time-fuse and
cap, the projectile may be adapted to be exploded during its flight.
When the object fired at is an armour plate, or like hard substance, the
projectile may be exploded by impact alone without detonating cap or supple-
mental heating agent, it is preferred however, to intensify the heating action of
the impact in such case by employing a firing pin 9, as shewn in Figure 2, which
extends from the point of the projectile into the cavity thereof and may have at its
rear end an enlarged head or piston 10. When the projectile strikes, the firing pin
and its head are forced in so as to compress the explosive thereby heating and
exploding it.
Although it is known that dynamite and nitro-glycerine are rendered difficult
to explode by cooling them below 40° F., my correspondent is not aware that any
practical use has been made of this knowledge, or that it is known that while
frozen nitro-glycerine is practically non-explosive in a gun when it is used to
charge projectiles, it can be heated and exploded after being fired from the gun.
The freezing of nitro-glycerine has practically been avoided owing to its non-
explosive properties while in that condition, and the danger of accidental explosion
in case of its being thawed by artificial means.
It is to be understood that this invention is not only applicable to nitro-
glycerine or its compounds, such as dynamite, but also to other high explosives
which can be rendered less explosive by cold, and that the charge may be
introduced into the cavity of the projectile without a case enclosing it.
When surrounding the charge of frozen dynamite with powder, as above stated
this will also act as an envelope of a bad conductor of heat which will greatly
retard the conduction of heat to the charge from the outside, so that this arrange-
ment will be employed with advantage in cases where the shell has to be kept for
some time in a heated gun before firing the same, or where the shell is used
against armour and it is desirable to retard the explosion to a period subsequent
to penetration. It will be obvious that for this purpose any other explosive that
is a bad conductor might be employed instead of gunpowder thus the accompanying
drawing shews a section of a shell in which the case 3 containing the charge of
frozen explosive is surrounded by an envelope 4 of guncotton which may
advantageously be introduced in a wet state, and, if necessary, also be frozen.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. The herein described method of enabling a powerful explosive, liable to be
exploded by concussion, to be used as charge for a shell, by freezing the explosive
or reducing it to a temperature at which it will not explode by concussion, and
firing it from the gun while in the said condition, substantially as described.
2. A projectile charged with powerful explosive liable to be exploded by
concussion, cooled to such a degree as not to be practically non-explosive when
fired from a gun substantially as described.
3. A projectile charged with frozen dynamite, substantially as described.
4. In a projectile such as is referred to in the preceding claims, surrounding the
charge of explosive reduced to a low temperature with another explosive that will
act as a bad conductor of heat, substantially as described.
5. In a projectile such as is referred to in Claims 2 and 3, in combination with

page_text: the cooled explosive charge, a time-fuse, a detonator and a charge of gunpowder
or other relatively low explosive substantially as and for the purpose set forth.
6. In a projectile such as is referred to in Claims 2 and 3, in combination with
the cooled high explosive charge, a firing pin or rod which effects the compression
and firing of the explosive on the projectile striking the object fired at.
Dated this 26th day of August 1897.
ABEL & IMRAY,
Agents for the Applicant.