Year: 1886

page_text: I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, of 52 Chancery
Lane, London, in the County of Middlesex, Patent Agents, do hereby declare the
nature of this invention, which has been communicated to me from abroad by
Thomas J. Middleditch, of 325 Carlton Avenue, Brooklyn, in the County of Kings,
and State of New York, United States of America, Printer, to be as follows:-
The present invention relates to the manufacture of cartridges in which the
powder used is compressed while in a moist condition into a solid mass enclosed
within a shell.
.
These cartridges consist of a metallic shell or case open at the front end and
closed at the rear end and charged with a solid cake of powder pierced longitudinally
with a central perforation. The fulminate cap or other priming material is placed
preferably at the centre of the head, and when exploded ignites the powder along
the central perforation. The powder cake is made of such density that when
ignited the combustion takes place at the surface only; and the cake is so encased
by the shell that its outer cylindrical surface and its rear end are protected from
the action of the fire of ignition.
When such a charge is fired, the surface of the perforation only is at first ignited,
and such surface being comparatively small the initial pressure exerted upon the
projectile is correspondingly low; but, as the combustion proceeds, the fire surface
constantly extends and the pressure exerted upon the projectile is thereby
substantially maintained or is increased during the passage of the projectile up the
bore of the gun. This causes the projectile to start easily and with little strain on
the gun, but by maintaining or increasing the pressure upon it gives it a velocity
at the muzzle of the gun much higher than is obtained from the common arrange-
ment of loose grain powder.
It is to be. particularly noted that the powder cake of such cartridges is to be
non-granular in structure and so compressed into a solid mass that, when ignited,
the fire will not penetrate into or through the cake; but will be confined to its inner
surface. If the cakes of powder were to be made of common grain powder pressed
into form, their mass would be more or less, granular, and when ignited the fire

page_text: would be likely to run along the surfaces of the grains and so penetrate into the
cake and disrupt it, thus preventing the regular and continuous increase of the fire
surface.
In the application of this principle of construction to cartridges for ordnance,
more than one powder cake is sometimes used in one shell; and in such case the
perforated cakes are grouped together within a common shell each being protected
on its outer surface and rear end as in the case of a single cake; or a single large
cake is used which is pierced with various longitudinal holes.
The present invention relates to an improved method of making cartridges of
the above-described construction; and the novel feature of the invention consists
in submitting the charged shells to the action of a vacuum and a moisture-
condensing or absorbing apparatus, constructed and arranged to exhaust the air
from the cartridges and take up the moisture or vapor of water in the air as it is
drawn from the shells.
The vacuum chamber is connected through a pipe to a condenser, which in turn
is connected with an air exhaust pump. The vacuum chamber may be of any
suitable form constructed to receive any convenient number of cartridges, and
adapted to be closed air tight. The condenser may be of any construction or kind;
it is, however, to be arranged between the vacuum chamber and the air-exhausting
punip, and must be adapted to condense or absorb the moisture of the air drawn
from the vacuum chamber. For this purpose, I prefer to fill the condenser with
small pieces of pumice stone, which, previous to drying a quantity of cartridges, is
saturated with sulphuric acid, which has a strong affinity for vapor of water and
readily absorbs the moisture from the air as it is drawn through the pumice stone.
Ice, however, may be used in the place of the pumice stone and sulphuric acid, and
the action then would be to condense the moisture of the air drawn off by the
pump. The air pump may be of any suitable. construction. A gauge is attached
to the pipe leading from the vacuum chamber to the pump and is for indicating to
what extent the air is exhausted from the chamber. The condenser is provided
with a cock to draw off the acid or other liquid that may collect in the bottom.
The charged cartridge shells, in any suitable quantity or arrangement, are put in
the vacuum chamber and the chamber closed air tight. Preferably, though not
necessarily, the vacuum chamber is heated so as to raise the temperature of the
powder cakes considerably above their normal temperature, but not to the point
where the form or condition of the cakes will be undesirably affected. The
exhaust pump is now put in operation and by a few strokes produces a partial
vacuum in the vacuum chamber, and draws off the moisture from the powder cakes,
which is absorbed or condensed before it reaches the air pump. The cartridges
need remain in the partial vacuuin only for a few minutes, when they can be taken
out sufficiently dry for immediate use.
The utility of the condensing or absorbing apparatus lies in the fact that the
pump alone could not readily and effectively remove the vapor of water or other
moisture, because of the greatly increased volume of such vapor at low pressure,
and particularly because it would condense in front of the descending piston of the
pump instead of being forced against the pressure of the atmosphere, and when
the piston rises it would flash into vapor again and fill the pump, thus preventing
the withdrawing quickly of either air or vapor from the vacuum chamber. But with
a condensing or absorbing apparatus arranged between the vacuum chamber and
the pump, the moisture of the air is taken up, and the air may be exhausted and
the powder cakes dried with great rapidity, and without affecting the cakes in any
way not desired.
As intimated above, this drying operation may be carried on so as to alter the
character of the powder cakes, and thus the manuer of their burning; and I avail
of this capability of the drying mechanism to prepare cartridges for special work
or uses. Thus, it is found that the drying may be so forced as to draw the
moisture from a powder cake, particularly if it be lightly compressed, in. such
manner as to leave it comparatively porous, and thus cause it to burn very rapidly.

page_text: again, a cake may be so dried as to cause much of the nitre of the powder cake to
be drawn to its igniting surface, and in such case the rate of combustion will be
slow at the first moment of ignition, but will rapidly increase as combustion
proceeds. These various conditions may be adopted to produce cartridges which,
for a given quantity of powder, or a given size of shell and central perforation,
shall have different times of burning, or a varying rate in the time of burning, as
may be required for different guns, or with different projectiles and bores. The
condition, however, that is believed to be most essential, is that which brings the.
nitre of the powder to the igniting surface and causes the rate of combustion to
increase from the moment of ignition to the end of the burning; and this is
because such rate of burning augments the effect produced by this particular form
of powder cake. That is, the volume of gases first developed will be small both
because the surface ignited is small, and also because the rate of combustion is at
this time slow; and the rapid and continuous increase in the volume of gases
will be caused both by the extending fire surface and by the increasing rate of
combustion.
I do not limit myself to the exact construction of drying apparatus described
herein, as this may be modified in many ways without departing from the principle
of its desired operation. It is manifest also that the method is applicable not only
to the drying of the powder cakes of small cartridges, but also to drying the
powder cakes of large cartridges, in which there may be a single cake pierce
with various igniting holes, or several powder cakes each pierced with one or more
such holes.

page_text: Improvements in the Manufacture of Cartridges.
I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, of 52 Chancery
Lane, London, in the County of Middlesex, Patent Agents, do hereby declare the
nature of this invention, which has been communicated to me from abroad by
Thomas J. Middleditch, of 325 Carlton Avenue, Brooklyn, in the County of Kings,
and State of New York, United States of America, Printer, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
The present invention relates to the manufacture of cartridges in which the
powder used is compressed while in a moist condition into a solid mass enclosed
within a shell, and it relates more especially to cartridges of the general character
shown in Fig. 2 of the accompanying drawing.
These cartridges consist of a metallic shell or case open at the front end and
closed at the rear end and charged with a solid cake of powder pierced longi-
tudinally with a central perforation. The fulminate cap or other priming material
is placed preferably at the centre of the head, and when exploded ignites the
powder along the central perforation. The powder cake is made of such density
that when ignited the combustion takes place at the surface only; and the cake is
so encased by the shell that its outer cylindrical surface and its rear end are
protected from the action of the fire of ignition.
When such a charge is fired, the surface of the perforation only is at first ignited,
and such surface being comparatively small the initial pressure exerted upon the
projectile is correspondingly low, but, as the combustion proceeds, the fire surface
constantly extends and the pressure exerted upon the projectile is thereby sub-
stantially maintained or is increased during the passage of the projectile up the
bore of the gun.
This causes the projectile to start easily and with little strain ou
the gun, but by maintaining or increasing the pressure upon it gives it a velocity
at the muzzle of the gun much higher than is obtained from the common arrange-
ment of loose grain powder.
It is to be particularly noted that the powder cake of such cartridges is to be
non-granular in structure and so compressed into a solid mass that, when ignited,
the fire will not penetrate into or through the cake but will be confined to its
inner surface. If the cakes of powder were to be made of common grain powder
pressed into form, their mass would be more or less granular, and when ignited the
tire would be likely to run along the surfaces of the grains and so penetrate into
the cake and disrupt it, thus preventing the regular and continuous increase of the
tire surface.
In the application of this principle of construction to cartridges for ordnance,
more than one powder cake is sometimes used in one shell; and in such case the
perforated cakes are grouped together within a common shell each being protected
on its outer surface and rear end as in the case of a single cake; or a single large
cake is used which is pierced with various longitudinal holes.
The present invention relates to an improved method of making cartridges of
the above-described construction; and the novel feature of the invention consists

page_text: in submitting. the charged shells to the action of a vacuum and a moisture-
condensing or absorbing apparatus, constructed and arranged to exhaust the air
from the cartridges and take up the moisture or vapor of water in the air as it is
drawn from the shells.
In the accompanying drawings Fig. 1 represents a vacuum or air-pumping
apparatus adapted to drying the cartridges, in accordance with the present
invention; and Fig. 2 is a central longitudinal section of a cartridge shell charged
with a cake of hard powder, in the manner above indicated.
Referring to these views, and first to Fig. 2, A represents the metallic shell of a
cartridge, which may be of any desired proportions and form. Usually such shells
are made cylindrical with their heads B integral with the sbell, and are capped
or otherwise provided with a primer before they are charged with powder.
C represents the powder cake, which is perforated with a central longitudinal
hole D. This powder cake is made from slightly moistened meal powder, which is
pressed into the shell around a rod arranged centrally in the shell to form the
perforation D. Instead of meal powder, common granulated powder may be used
to form the cake C; but in such case the granular powder must be first reduced to
substantially the ungranular condition of meal powder, and sufficiently moistened
so that it can be readily moulded and compressed into form.
Referring to Fig. 1, E is a vacuum chamber, connected through pipe F to a
condenser G, which in turn is connected with an air exhaust pump H.
The
vacuum chamber may be of any suitable form constructed to receive any
convenient number of cartridges, and adapted to be closed air tight. The con-
denser may be of any construction or kind; it is, however, to be arranged between
the vacuum chamber and the air exhausting pump, and must be adapted to
condense or absorb the moisture of the air drawn from the vacuum chamber. For
this purpose I prefer to fill the condenser with small pieces of pumice stone I,
which, previous to drying a quantity of cartridges, is saturated with sulphuric
acid, which has a strong affinity for vapor of water and readily absorbs the
moisture from the air as it is drawn through the pumice stone. Ice, however, may
be used in the place of the pumice stone and sulphuric acid, and the action then
would be to condense the moisture of the air drawn off by the pump. The air
pump may be of any suitable construction. A gauge J is attached to the pipe
leading from the vacuum chamber to the pump and is for indicating to what
extent the air is exhausted from the chamber F. The condenser is provided with
a cock K to draw off the acid or other liquid that may collect in the bottom.
The charged cartridge shells, in any suitable quantity or arrangement, are put
in the vacuum chamber and the chamber closed air tight. Preferably, though not
necessarily, the vacuum chamber is heated so as to raise the temperature of the
powder cakes considerably above their normal temperature, but not to the point
where the form or condition of the cakes will be undesirably affected. The exhaust
pump is now put in operation and by a few strokes produces a partial vacuum in
the vacuum chamber, and draws off the moisture from the powder cakes, which is
absorbed or condensed before it reaches the air pump. The cartridges need remain
in the partial vacuum only for a few minutes, when they can be taken out
sufficiently dry for immediate use.
The utility of the condensing or absorbing apparatus lies in the fact that the
pump alone could not readily and effectively remove the vapor of water or other
moisture, because of the greatly increased volume of such vapor at low pressure,
and particularly because it would condense in front of the descending piston of the
pump instead of being forced against the pressure of the atmosphere, and when
the piston rises it would flash into vapor again and fill the pump, thus preventing
the withdrawing quickly of either air or vapor from the vacuum chamber. But
with a condensing or absorbing apparatus arranged between the vacuum chamber
and the pump, the moisture of the air is taken up, and the air may be exhausted
and the powder cakes dried with great rapidity, and without affecting the cakes in
any way not desired.

page_text: As intimated above, this drying operation may be carried on so as to alter the
character of the powder cakes, and thus the manner of their burning; and I avail
myself of this capability of the drying mechanism to prepare cartridges for special
work or uses.
Thus, it is found that the drying may be so forced as to draw the
.moisture from a powder cake, particularly if it be lightly compressed, in such
manner as to leave it comparatively porous, and thus cause it to burn very rapidly;
again, a cake may be so dried as to cause much of the nitre of the powder cake to
be drawn to its igniting surface, and in such case the rate of combustion will be
slow at the first moment of ignition, but will rapidly increase as combustion
proceeds. These various conditions may be adopted to produce cartridges which,
for a given quantity of powder, or a given size of shell and central perforation,
shall have different times of burning, or a varying rate in the time of burning, as
may be required for different guns or with different projectiles and bores. The
condition, however, that is believed to be most essential, is that which brings the
nitre of the powder to the igniting surface and causes the rate of combustion to
increase from the moment of ignition to the end of the burning; and this is because
such rate of burning augments the effect produced by this particular form of
powder cake. That is, the volume of gases first developed will be small both
because the surface ignited is small, and also because the rate of combustion is at
this time slow; and the rapid and continuous increase in the volume of gases
will be caused both by the extending fire surface and by the increasing rate of
.combustion.
I do not limit myself to the exact construction of drying apparatus shown and
described herein, as this may be modified in many ways without departing from
the principle of its desired operation. It is manifest also that the method is
applicable not only to the drying of the powder cakes of small cartridges, but also
to drying the powder cakes of large cartridges, in which there may be a single cake
pierced with various igniting holes, or several powder cakes each pierced with one
or more such holes
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. The herein described method of making cartridges, which consists in com-
pressing the powder while in a moist and non-granular condition into a solid cake
within the shell, substantially as set forth, and then drying the powder by means
of a vacuum and moisture-condensing or absorbing apparatus.
2. The herein described process of treating the solid charges of cartridges, to
produce a varying rate of combustion of such charges, which consists in submitting
such charges while in a moist condition to the energetic action of a vacuum in
connection with a moisture-absorbing or condensing apparatus.
3. A cartridge, consisting of a shell A B charged with a cake of powder C
perforated by a central longitudinal hole D, said cake being protected by the shell
from the action of fire on its outer cylindrical surface and at its ear end, and
consisting of powder made to have an increasing rate of combustion from the
Burface of the perforation to the exterior cylindrical surface of the cake.
Dated this 3rd day of June 1886.