IMPROVEMENTS IN CARTRIDGES FOR ORDNANCE
Year: 1885

page_text: COMPLETE SPECIFICATION,
I, AZEL STORRS LYMAN, of Brooklyn, New York, chemist, United States of
America, do hereby declare the nature of my invention for "IMPROVEMENTS IN
CARTRIDGES FOR ORDNANCE," and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement,
reference being had to the accompanying drawings, forming part of this
specification:-
The invention relates to cartridges for use in large guns or cannon.
The object
of the invention is to so arrange the powder used in such guns, that when it is first
ignited its fire surface will be comparatively small and the initial pressure
developed correspondingly low, and so that the fire area will continuously increase
during the burning of the charge and thereby maintain a uniform or continuously
increasing pressure upon the projectile; the effect being to start the projectile
easily and slowly, but to communicate to it a rapidly increasing motion throughout
the entire bore of the gun, and thus relieve the walls of the gun from such sudden
and heavy strain, as, with common forms of cartridges, is developed when the fire
surface is greatest at or near the moment of ignition and when, consequently, a
very high maximum pressure is suddenly developed before the inertia of the shot
has been overcome.
The invention consists of a cartridge composed of powder compacted into a solid
cake within a shell or case, the cake of powder being arranged so that its outer
surface, or such outer surface and its rear end, is protected from primary ignition
by such shell, and being pierced longitudinally by holes running from end to end of
the cake; the invention also consists in making the cartridge of several cakes of
powder grouped together, all the cakes being protected as described upon their
outer surfaces and rear ends and being each pierced by one or more holes; and the
invention consists, further, in various novel features relating to the construction
and arrangement of the cartridge head, whereby the entire surfaces of all the holes
of the powder cake or cakes may be simultaneously ignited, all as will be herein-
after fully described.
In the drawings, Fig. 1 is a longitudinal section of the breech of a gun containing
a cartridge embodying my invention in position for firing; Fig. 2 is a cross-section
of the cartridge; and Figs. 3, 4 and 5 show cross-sections of modified forms of the
cartridge

page_text: Referring to these views in detail, A is the chamber of the gun; B is the breech
block which holds the cartridge in place, and C is a wedge for securing the breech
block; which parts, it is to be understood, may be of any suitable construction,
D is the cartridge shell or case, and E is the powder cake packed or otherwise
placed in the shell with its outer cylindrical and rear end surfaces protected from
the action of fire by the shell and the head F of the shell. G represents longi-
tudinal holes running through the powder cake from end to end, and also through
the head of the cartridge. H is a firing tube passing centrally through the powder
cake and designed to convey the igniting flame to the front end of the cake. This
tube projects rearwardly from the cartridge head, in which it is made fast, and
bears against the breech block, thereby separating the cartridge head from the
breech block and leaving a space I between such head and block; and the
cartridge head is located somewhat within the shell, as shown, so that the end of
the shell may also bear upon the breech block.
To fire the cartridge, a flame is forced down the firing tube and ignites the front
end of the powder cake, then, flashing back down the perforations in the powder
cake, it ignites simultaneously the entire surfaces of all the holes through the
powder cake. The whole fire surface at the moment of ignition is comparatively
small, and hence the initial pressure is correspondingly low; but as the burning
proceeds in a radial direction, the holes in the powder cake constantly enlarge and
the fire areas continuously increase, as also does the pressure upon the projectile,
and its dead inertia is thus gradually and slowly overcome. After the projectile
has been started from its seat, and as it passes through the gun, the pressure
'exerted upon it is substantially maintained or continuously increases, according to
the rapidity of increase in the fire area, until the powder cake is practically all
.consumed.
1
The particular object of the chamber I behind the cartridge head, is to permit
the perforations through the powder cake to communicate with one another to
ensure their being all instantly ignited throughout their whole extent. Thus, if
these holes were closed at their rear ends, they would be likely to become more or
less filled with gases upon the first flash of ignition at their front ends, which
would tend to prevent their entire surfaces being instantly ignited, and this would
interfere with the intended uniformity of the radial burning and the continuous
increase of the burning area. But when these holes open into a common space, or
communicate with one another in any other way so that the gases pass freely out
of the holes and do not choke them, the entire surfaces of all the holes are
simultaneously and instantly ignited, and the progress of the radial burning is
substantially the same in all parts of the powder cake.
The distance of the perforations in the powder cake from one another determines
the time of the burning, and this distance should be proportioned to the length of
the barrel and the rapidity with which the powder burns.
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.

page_text: The powder may be packed in the shell or shells while in a suitably soft or
plastic condition, or the powder cake may be formed outside of the shells and
afterward inserted therein. It is essential that the powder cake be solid and
dense; that is, it should be ungranular throughout its entire mass and not like a
mass of separate grains or blocks of powder; for it is necessary to have the
combustion take place only on the surface of the cake, and that the fire shall not
penetrate into or through the mass of the cake as it does in the case of a mass of
granular powder. It is also necessary that the powder cake be so firmly fixed
within the shell that it will not be moved from its seat during its combustion.
One method of making a cake of powder that will fulfill these requirements of
the invention, is to employ powder meal, which is to be slightly moistened and
then compacted into a cake of the desired shape and preferably within the shell;
but howsoever the cake may be made, the cssential requisite is that it shall be of
such density or solidity that the fire will not penetrate into or through it, but will
be confined entirely to its exposed surface.
Although I prefer to ignite the powder in the manner set forth, it is quite
possible and in some cases may be found more desirable-to ignite it by throwing
igniting flames along the holes from the rear end of the powder cake. In such
case, the central firing tube would not be required; and some form of priming
material, suitably arranged at the rear of the cartridge, might be used. So, too,
the firing of the charge might be effected from its front end in other ways; and
I do not, therefore, limit myself to any particular way or means for igniting the
charge.
Fig. 3 illustrates a modified form of cartridge for large guns, in which there are
inner tubes or cases J concentric with the outer casc D, and having braces K
between them. These cases are charged with cakes of powder E, which are
perforated by longitudinal holes G, and there is a central firing tube H. Fig. 4
shows a number of small cylinders L, each charged with a powder cake having a
single perforation, and all packed solidly within the large or exterior shell D.
Fig. 5 shows large and small interior cylinders M N packed solidly within the
exterior shell, and each having one or more perforations according to their size.
The construction of the cartridge may be varied to a still greater extent; but the
forms shown suffice to illustrate how in practice the invention may assume
different forms.
I do not propose here to claim a cartridge having a solid cake of powder
perforated by a single hole, as such form of cartridge is not applicable to use in
large guns, being used only in small arms. For large guns such a cartridge would
not serve the purpose of the forms here shown; and this is because the thickness
of the walls of the powder cake should not be greater than what can be burned
through before the projectile leaves the gun; and, further, the desired rapidity of
increase in fire area cannot be had, with a powder cake having a single perforation
large enough to produce the initial pressure required with heavy projectiles, but
can be had with a cake or cakes having a number of perforations that together
have enough exposed surface to develop such initial pressure.
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 solid cake of powder having
longitudinal holes running through it from end to end, such cake of powder being
protected from the action of fire upon its outer surface by said shell, substantially
as and for the purpose set forth.
2. A cartridge, consisting of a shell charged with solid cakes of powder packed
in the shell and extending from end to end of the charge, the cakes of powder
being each protected upon their outer surfaces from the action of fire, and being
also each perforated with one or more longitudinal holes, substantially as and for
the purpose set forth,

page_text: 3. A cartridge, consisting of a shell charged with a solid cake of powder which
is protected upon its outer surface from the action of fire by said shell, and is
protected at its rear end by the head of said shell, said cake and the head of the
shell being perforated by longitudinal holes, substantially as and for the purpose
set forth.
4. A cartridge, consisting of a shell charged with a solid cake of powder
perforated by longitudinal holes extending also through the head of the cartridge,
the cartridge being provided with a projection extending rearwardly from its head
and adapted to bear against the gun and thereby form an open space back of the
head of the cartridge when in the gun, substantially as set forth.
5. A cartridge, consisting of a shell charged with a solid cake of powder
perforated from end to end by longitudinal holes extending also through the
cartridge head, and provided with a firing tube arranged to direct an igniting
flame to the front end of the powder cake, substantially as and for the purpose
set forth.