Improvements in Projectiles for Ordnance and Especially Projectiles for Piercing Armour Plates.
Year: 1886

page_text: Date of Application, 16th Dec., 1886
Complete Left, 16th Sept., 1887
Complete Accepted, 29th Nov., 1887
PROVISIONAL SPECIFICATION.
Improvements in Projectiles for Ordnance and Especially Projectiles
for Piercing Armour Plates.
I, RICHARD CAIL of Newcastle on Tyne in the County of Northumberland, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object improvements in projectiles for ordnance and
especially projectiles for piercing armour plates. For this purpose I make the nose of
the projectile of a conical form and upon the face of the cone I form a spiral groove
or screw. The side of the groove is parallel to the axis of the projectile and presents
a square shouldered cutting edge in the direct line of force which as the projectile
penetrates the plate acts progressively to pare away the sides of the holo produced by
the pointed end of the projectile and enlarge the hole to the full size to admit the body
of the projectile to pass through. I prefer to employ a gun with a smooth bore and
to obtain the rotation of the projectile by a suitable configuration of its exterior.
I provide a gas check upon the rear of the projectile consisting of a copper ring
angular in section; it is attached by tap screws to the flat base of the projectile and
also it bears against the bore of the gun.
The pressure of the powder gases causes the gas check to make a gas tight closing.
In the angle of the gas check I provide a wire ring to ensure the proper expansion of
the gas check when the charge is fired. This ring is soldered in. These projectiles
can be loaded either from the muzzle or rear, and are suitable for smooth or
rifled guns.
Dated this 16th day of December 1886.
CARPMAEL & Co.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Projectiles for Ordnance and Especially Projectiles
for Piercing Armour Plates.
1, RICHARD CAIL of Newcastle on Tyne in the County of Northumberland, 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 :—
This invention has for its improvements in projectiles for ordnance and especially
projectiles for piercing armour plates.
For this purpose I make the nose of the projectile of a conical form and upon the -
face of the cone I form a spiral groove or screw. The side of the groove is parallel
to the axis of the projectile and presents a square shouldered cutting edge in the
direct line of force which as the projectile penetrates the plate acts progressively to
paro away the sides of the hole produced by the pointed end of the projectile and
enlarge the hole to the full size to admit the body of the projectile to pass through
without incurring the lateral resistance in the plate to be pierced to which the ordinary
segmental point is subjected.
I prefer to employ a gun with a smooth bore and to obtain the rotation of the pro-
jectile by a suitable configuration of its exterior.
I provide a gas check at the rear of the projectile consisting of a copper ring
angular in section it is attached by tap screws to the flat base of the projectile and also
it bears against the bore of the gun or the gas check may consist of a cylindrical
ring fastened by tap screws having a fillet on the base of the projectile. Those
projectiles can be loaded either from the muzzle or rear and are suitable for smooth
or rifled guns.
In order that my said invention may be most fully understood and readily carried
into effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows a side view partly in section of a projectile constructed in accordance
with my invention.
Figure 2 shews a transverse section on the line X. Y. Figure 1.
Figure 3 shows a rear view and
Figure 4 is a section showing an alternative form of gas check.
As is seen in Figure 1, the nose of the projectile is made with a square shouldered
spiral groove a a around it. bb are the grooves around the body of the projectile by
which it is rotated when fired from a smooth bore gun. These grooves extend from
the front end of the body to within a short distance from the rear end.

page_text: is the gas check which may either be made of angular section as shewn in
Figure 1 or it may be a cylindrical ring fixed on the side of projectile with tap screws
as shewn in Figure 4.
This gas check makes a tight joint between the projectile and the bore but inclined
holes d d are bored outwards and forwards from the rear of the projectile to the ends
of the rifle grooves upon its surface and allow gas to pass into the open rifled grooves
or tubes.
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 projectile having around its nose a spiral groove having an angular cutting
edge substantially as described.
2. A gas check with a ring of angular section substantially as shewn in Figure 1.
3. A gas check consisting of a cylindrical ring with a fillet upon it at the base of
the projectile substantially as shewn in Figure 4.
4. Projectiles which are caused to rotate by the configuration of the exterior and
which are provided with gas checks substantially as described.
Dated this 16th day of September 1887.
CARPMAEL & Co.,
Agents for the Applicant.