Improvements in Rifled Ordnance and Projectiles therefor.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Rifled Ordnance and Projectiles therefor.
I, GILBERT RUGGLES ELLIOTT of 73 Warren Street, Boston, Massachusetts,
United States of America, Civil Engineer 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 :-
The present invention relates primarily to the manner of discharging a projectile
from a gun, that is to say, it is the object of the invention to arrange the charge or
charges of a gun upon the accellerating plan, or so that the projectile will not
receive the full effect of the whole powder charge upon ignition thereof, but will
at intervals, while passing up the barrel of the gun, receive the impulses of various
separate and successively ignited charges arranged to add their gases to the
column of gas already behind and then propelling the projectile.
By this arrangement of the propelling charges it is designed to overcome the
momentum of the projectile at a low pressure and with comparatively light strain
upon the gun, and to maintain a low maximum pressure upon the projectile during
the time it is in the gun, whereby a high velocity of the projectile will be secured
without severe strain upon the gun.
The special object of the invention is to separate the various charges so that
they cannot ignite from one another, and to successively ignite them by mechanical
means caused to operate by a special form of grooving in the gun.
The invention therefore consists of a rifled gun provided with one or more
grooves crossing the rifling, which grooves are designed to receive a projection or
projections on a movable part of the projectile, and thereby to hold such part
against revolving with the projectile as it is turned by the rifling, and to cause
explosive charges in the projectile to be successively ignited as it passes up the
bore of the gun.
The invention also consists of a projectile having several separate chambers at
its rear end for receiving explosive charges, cach such chamber being provided
with mechanical exploding apparatus for igniting its contents which exploding
devices are operated by the rifling of the gun.
Referring to the drawings,
Figure 1 is a longitudinal section of a gun rifled on the plan of the invention.
Figure 2 is a plan view of the projectile embodying the invention.
Figure 3 is an elevation view of the rear end of the same.
Figure 4 is a section, on an enlarged scale, of a portion of the rear end of the
projectile, the section being taken through one of the circumferential chambers and
through the centre chamber.
Figure 5 shows a detail enlarged view of what I term the firing ring of the
projectile.
Figure 6 is a section similar to that of Figure 4 showing a modification.
Referring to these views more fully, A represents the projectile, which in general
form is of the usual construction of projectiles for rifled guns. B is the sabot ring
designed to take the rifling of the gun. This ring may be of any desired form or
may be substituted by studs; in the present case I have shown a sabot ring having
studs or projections C corresponding in position to the grooves on the inner surface
of the barrel of the gun.
In the rear end of the projectile is a central chamber D which is surrounded by
other like chambers E. These chambers are designed to receive charges of powder
or other explosive material and are then closed by the discs F, which discs may be
made of wood, paper, packing or other like material, such material being preferred
to metal. The central chamber D is provided with a firing hole G which is located

page_text: so as to register with the vent hole of the gun when the projectile is in position for
firing. Each of the other chambers has at its rear end a firing hole H, which
communicates with the anvil of the detonating cap 1. Just above this anvil and
in a circular, radial hole is arranged a firing pin J having a cam head K.
L is a
spring on the firing pin arranged between its head K and a shoulder just above the
anvil of the detonator I, and is of sufficient strength to hold the firing pin off the
explosive cap. M is the firing ring. This ring lies in a circular groove in the outer
surface of the projectile and flush therewith. The inner surface of this firing ring
is provided with two or more cams N, which are of the same width as the thickness
of the heads of the firing pins, and which project into a shallow groove, at th
bottom of the groove of the ring M, into which shallow groove the heads K also
project. The firing ring is free to move circularly in its groove, and by such
movement its cams N are brought into contact with the firing pins and force their
points upon the detonating caps to explode them. Upon the outer face of the
firing ring are one or more projections or lugs O, which are of the width of the
grooves of the gun (to be hereafter described) and of a height corresponding to
the depth of such grooves. These lugs are preferably longer than the width of
the firing ring so that they may have an extended bearing in the grooves of the
gun to prevent their leaving such grooves when the projectile is fired.
Referring now to Figure 1, P represents the ordinary grooves of the rifling,
and Q the lands. This rifling may be of any suitable pitch and of any desired
number, width and depth of grooves. R represents one of two straight grooves
which are parallel to and in the plane of the axis of the gun. These straight
grooves are preferably of the same width and depth as the inclined rifling which
they cross.
As the
The projectile, having its chambers charged with powder or other explosive
material, is to be placed in the breech of the gum with its studs O in the grooves R,
in which position its studs C will of course be in the grooves P, and this will bring
the firing hole G of the central chamber of the projectile opposite the vent of the
gun. Now, upon applying an igniting flame to the vent of the gun, the explosive
in the central chamber of the projectile will be ignited, and its confining wad or
disc will be blown out and the rear end of the gun will be filled with the gases of
explosion, and the projectile started forward along the barrel of the gun.
projectile moves up the barrel the rifling will cause it to turn upon its axis, but
the straight grooves will hold the firing ring from turning with the projectile, so
that very soon after the projectile has commenced to move forward one of the cams
of the firing ring will be forced against a firing pin and another loaded chamber in
the projectile will be exploded, and this action will be repeated until all the loaded
chambers have been exploded. In this way successive impulses will be given to
the projectile, so that an increasing volume of gas behind the projectile will be
preserved and the pressure of the saine kept up during the passage of the projectile
to the muzzle of the gun. By these means it will be seen that a practically
constant pressure may be preserved upon the projectile during its passage up the
barrel, and hence that a higher velocity may be given to it with less strain upon
the gun, than is possible where the whole powder charge is exploded at once.
these means the various charges may be positively exploded at times best suited
to accomplish the desired results, that is, they may be timed so as to add their
gases to the column of gas behind the projectile at just the instant of time when
such addition is required to maintain the proper pressure upon the projectile.
By
I have shown the grooves in the gun that hold the firing ring against rotation
as straight and of practically the same form as the rifling, but this is not essential.
It may be preferred in some cases to use but a single groove, or to make such
groove or grooves deeper or of different form than the rifling. So, too, this groove
may be inclined to a plane of the axis of the gun; that is to say, so long as this
groove crosses and is not of the same pitch as the rifling it will accomplish its
purpose, and, as in the case of a very flat rifling, it may be essential to give the
groove an inclination or opposite pitch in order to properly time the ignition of

page_text: the various charges. And therefore I do not confine myself to any special form
of groove further than that it must cross the rifling and be inclined thereto.
It will be understood that the firing ring of the projectile may have- more than
two cams, or less as the case may be also that it may be provided with any
suitable device for locking it against rotation while the projectile is being handled
and after it has been charged. I do not therefore limit myself to any special
arrangement of the firing parts of the projectile, as the form to be used in any one
case will depend upon the results sought to be accomplished. Neither do I
confine myself to the general form of firing pin and its detonating cap and anvil,
for various of the well known firing devices may serve in lieu thereof, (thus in
Figure 6 show soft metal caps S that may be cut by the cams U, thus exposing
the inner ends of the powder charges, through grooves T to ignition by the gases
evolved by the primary charge) or the ring might be arranged to act directly
upon the fulminates. I have shown one form of igniting apparatus to illustrate
the principle of the invention, which generally speaking, includes the firing ring
of the projectile arranged to successively explode various loaded chambers, and
held from revolving with the projectile when in the gun by one or more grooves
in the barrel that cross the ordinary rifling or are inclined thereto.
I have explained the invention as applied to a projectile designed to carry its
primary charge, that is, the charge that first starts it up the barrel of the gun, but
it is obvious that the charges succeeding the primary charge may be as readily
exploded, and all their effects realized, if the projectile be started in the usual way
by a charge placed in the breech of the gun behind the projectile.
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 :-
First. A rifled gun or cannon provided with a groove crossing the lands and
grooves of the rifling, substantially as and for the purpose set forth.
Second. In a gun or cannon, the combination with the lands and grooves of the
rifling of the barrel, one or more grooves extending across the rifling and in a
direction inclined thereto, substantially as and for the purpose set forth.
Third. In combination in a projectile for rifled ordnance, two or more chambers
at the rear end of the projectile for carrying explosive material, a movable firing
ring surrounding the projectile and having a stul for taking in a groove in the
barrel of the gun whereby the ring is held against rotation while the projectile is
being turned by the rifling of the gun, and detonating mechanism arranged between
said chambers and the firing ring, substantially as described.
Fourth. In combination in a projectile, a sabot by which the projectile is caused
to take the rifling of the gun, a firing ring M surrounding the projectile and having
cams N and projections or lugs O, chambers E for carrying explosive material
ocated in the base of the projectile, and a firing pin J arranged in the path of the
said cams F, substantially as described.
Fifth. In combination in a projectile for rifled guns, the chamber D provided
with an igniting hole G located to communicate with the vent of the gun,
chambers E, the movable firing ring M surrounding the projectile and provided
with lugs O and cams N, and the firing pins J, substantially as described.
Dated this 19th day of May 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.