IMPROVEMENTS IN CARTRIDGES FOR SMALL ARMS
Year: 1885

page_text: I, AZEL STORRS LYMAN, of Brooklyn, New York, United States of America,
chemist, do hereby declare 'the nature of my invention for IMPROVEMENTS IN
CARTRIDGES FOR SMALL ARMS and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following state-
ment, reference being had to the accompanying drawings forming part of this
specification:-
The invention relates to cartridges for small arms or hand arms. The object of
the invention is to produce a cartridge by which a pressure may be exerted upon
a projectile that shall be uniform or constantly increasing during the time tho
projectile is passing through the barrel of the gun, thereby causing the projectile
to be started slowly, and with comparatively little strain upon the walls of the
gun, but giving it continuously increasing motion during its passage through the
barrel.
The invention consists in forming the powder into a solid cake within the
cartridge case or shell, which cake is pierced from end to end by a central
perforation, and is protected by the shell on its outer surface and rear end so
that only the surface of the perforation and the front end of the cake are exposed
to the igniting flame.
The igniting flame is thrown along the central perforation, the surface of which
is thus ignited throughout its entire extent, and the burning then proceeds in a
radial direction toward the exterior surface of the cake, thereby continuously
enlarging the burning surface and increasing the development of the gases
produced by the combustion of the powder, and exerting (according to the special
construction of the cartridge) a uniform or a continuously increasing pressure upon
the projectile while it is in the barrel of the gun.
Here a
In the drawings, Fig. 1 shows a central longitudinal and Fig. 2, a cross-section
of a cartridge embodying the invention and adapted for use in sinall arms.
represents a shell or case in which is packed the powder b, which is formed into
a single, hard, solid cake. The letter c indicates the central hole or perforation
extending through this cake, and through the rear end of the shell a The shell
may also contain a projectile arranged in any proper manner in front of the powder
cake. The cartridge may also be provided with any suitable primer or igniting
material, arranged so as to throw a stream of fire along the perforation through
the powder cake. This will ignite the powder along the internal walls of the
perforation; and, as the surface thus ignited is comparatively small, the volume

page_text: of gases at first generated will be correspondingly small, but as the combustion
proceeds the fire surface will continuously enlarge until substantially the entire
mass of the powder, is consumed. The effect produced by burning the powder in
this way, is that the initial pressure upon the projectile placed in front of the
charge is low (as compared with the initial pressure produced by the common forms
of cartridges), and by reason of this low pressure the projectile is started with a
correspondingly light strain upon the walls of the gun. As the projectile gains
velocity, the fire surface at the same time rapidly increases in extent, and a corre-
sponding increase in the volume and heat of the gases is produced, so that the
pressure upon the projectile is maintained or is also increased."
By properly proportioning the size and shape of the powder cake, relatively to
the projectile and the barrel of the gun, the force exerted upon the projectile by
the burning powder may be regulated practically at will, and therefore so as to
do the most effective work with any particular size of gun and projectile: the
cartridge may be so proportioned (and this, it is believed, will be found to be the
most desirable condition), so that the initial pressure exerted upon the projectile to
start it will be maintained substantially uniform during the entire progress of the
projectile through the bore of the gun; this being effected by constructing the
powder cake so that the rate of increase of its fire surface will be in accordance
with the rate of the increase in the velocity of the projectile. Instead of. thus
maintaining a constant pressure upon the projectile after its start and during the
time that it is in the barrel of the gun, the cartridge might be constructed so that
such pressure would continuously increase; and this, obviously, could be done by
constructing the powder cake so that the fire surface would have a rate of increase
more rapid than the increase in the velocity of the projectile.
The cartridge here described may be used for firing either bullets or shot. In
the latter case, the shot may be properly massed in front of the powder cake
according to any of the common methods.
It will be seen that the forward end of the powder cake is exposed to the
burning flame; but as the area of this end is small, and constantly becomes smaller
during the burning process, the burning at this end does not interfere with the
desired increase of burning surface. The rear end of the powder cake, however, is
protected; and this is deemed necessary to prevent ignition of such rear end
surface as a whole and the possible consequent breaking of the powder cake.
Ordinarily, with such a cartridge, the primer used would be applied at the rear
end; but such a cartridge may be ignited by priming material otherwise placed ;
the only condition being that the whole surface of the central perforation be
instantaneously ignited, so that the radial progress of the burning may be regular.
The character of the powder cake is an important feature of the invention. It
should be a dense, solid and compact mass, that is, it should not be granular or
composed of separate blocks or pieces compressed together or in any other way
arranged side by side. When a cake of powder, that is made into a solid
ungranular mass, is ignited, combustion will take place only on its surface; and,
if the cake have a uniform density, it will be burned away evenly on all sides. To
produce such a cake, powder meal or dust may be used. This powder meal, which
is in an exceedingly fine flour-like condition, may be moistened until it becomes
somewhat plastic or of a consistency adapting it to be molded and compressed into
a solid mass; and, while in this soft or plastic condition, it is properly compressed
in the cartridge shell, which shell should be held in a suitable die or holder and have
a central core running through it to form the perforation in the powder cake.
When the shell has been properly charged and the core withdrawn, the powder
cake is allowed to dry. Whether the cake be made in this way or by some other
method, it should be made so that when ignited the fire will be confined to the
surface of the cake, and will not penetrate into or through its mass; and the
powder cake should be so fixed within the shell that it will not be moved from its
seat during its combustion, and so that the surface in contact with the shell will
not be ignited.

page_text: The rapidity with which the powder burns, depends upon the porosity of the
cake; the harder and denser the cake is, the slower will be the combustion ; and
one method of predetermining this rate of combustion, is by the quantity of
moisture in the powder meal, and the extent to which the moistened powder is
compressed. If there be much moisture, and the cake be lightly compacted in the
shell, then the dried cake will be very porous, and the rate of combustion will be
rapid, and vice versa; but the porosity of the cake should never be such as will
permit the fire to so penetrate into the cake as to disrupt it.
The cartridge here shown and described is more particularly adapted to small
arms, or to small arms and certain small ordnance. The principle of the invention
when adapted to large guns and heavy projectiles, requires a cartridge of a special
construction differing materially from the cartridge here shown. This cartridge
will be made the subject of a separate application for letters patent, and need not
therefore be described here.
I am aware that cartridges have been made in which the charge consisted of a
cake or pellet composed of granulated powder; also, that in making such cakes a
very small percentage of water has been used to moisten the grains of powder;
also, that a perforated tube has been arranged along the center of a cartridge
charged with loose granular powder; but do not claim these forms, and they do
not embody my invention, for in them the powder is of such a granular character
that the fire penetrates into and through their mass and is not confined to a
continuously increasing surface of the cake, the perforations through the charges
being only employed to assist in distributing the igniting flame. So, too, water-
proof blasting cartridges have been made from hard cakes of powder which were
centrally pierced by a hole which was for the purpose of inserting a fuse or other
igniting device to the center of the charge; and this is not my invention, because,
among other things, the central perforation contains the igniting device, and so is
not left free and unobstructed so that its surface can be instantly ignited through-
out its whole extent, and hence the burning area will not continuously increase as
is required by my invention. However, the cake be made, it is essential that the
entire surface of the central perforation be instantly ignited, so that the fire surface
and consequent development of gases will continuously increase during substantially
the whole burning process; and I would have it understood, that I do not claim
any form of cartridge in which the last named two conditions are not embodied.
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, consisting of a shell charged with a cake of powder made solid
substantially as hereinbefore set forth, said cake of powder being pierced. longi-
tudinally by a free unobstructed perforation, as and for the purpose described.
2. A cartridge, consisting of a shell charged with a cake of powder made solid
substantially as hereinbefore set forth, said cake of powder being pierced longi-
tudinally by a free unobstructed perforation, and being protected from the action
of fire upon its outer surface and rear end by said shell, as and for the purpose
described.