Improvements in Projectiles for Ordnance.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Projectiles for Ordnance.
We, ARTHUR TREVOR DAWSON, Superintendent of Ordnance Works, and
GEORGE THOMAS BUCKILAM, Engineer, both of Vickers, Sons & Maxim Limited,
of 28, Victoria Street, Westminster, in the County of London, and Louis
SILVERMAN, of Vickers, Sons & Maxim Limited, Crayford, Kent, Engineer, do
hereby declare the nature of this invention to be as follows:-
Our invention relates to the construction of projectiles for heavy guns with
gas checks so arranged as to prevent or diminish the erosive effect of the explo-
sion of heavy charges.
The gas check according to our invention, whilst it forms a perfect check for
the gases, is not torn off by the rifling when the projectile is fired; the plastic
material which forms part of the gas check is guarded against deformation when
the projectile is stored on board ship or in the magazine, and it lubricates the
rifling as the projectile passes along the bore.
The erosion in the interior of gun barrels is principally caused by the passage
of the highly heated explosion gases between the projectile and the bore.
In order to prevent this, we provide the projectile near its base, behind the
ordinary driving band, with flanges preferably made of copper, forming between
them grooves for the reception of plastic packing and lubricating material.
These flanges may either be separately attached to the projectile, or they may be
formed on a ring or band, separate from or forming a continuation of the
driving band.
The flanges are made of such section, that whilst they offer sufficient support
for the plastic material between them, it requires comparatively little force
to make them take the rifling, and there is space between them into which any
one can fold back when it meets with excessive resistance, so that they are not
liable to be torn off during the passage of the projectile along the bore.
The flanges are preferably of such diameters that, when the projectile is
pushed home the rearmost flange comes first in contact with the interior surface
of the chamber and is bent somewhat back before the flange in front of it meets
the surface of the chamber. The rear flange is preferably made in the first
instance with an inclination rearwards. In this manner there is obtained a
perfect piston fit of the flanges and the plastic material between them, when the
projectile is pushed by the rammer, and, when the charge is fired, the rear flange
is caused to fit still more tightly by the pressure of the explosion gases.
The packing material placed in the grooves between the flanges consists pre-
ferably of asbestos saturated with wax, plumbago or other suitable lubricant.
The rings may be formed in semicircular sections or as complete circles like
spring piston rings, or they may he wound on the projectile. The packing
material is preferably covered by a thin metallic band which protects the packing

page_text: during the handling or storing of the projectiles. This cover may be a real wards
continuation of the driving band, or, in some cases, it may be dispensed with.
Dated this 25th day of April 1899.
ABEL & IMRAY,
Agents for the Applicants.
improvements in Frojectiles for Ordnance.
We, ARTHUR TREVOR DAWSON, Superintendent of Ordnance Works, and
GEORGE THOMAS BUCKILAM, Engineer, both of Vickers, Sons & Maxim Limited,
of 28, Victoria Street, Westminster, in the County of London, and LOUIS
SILVERMAN, of Vickers, Sons & Maxim Limited, Crayford, Kent, 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:-
Our invention relates to the construction of projectiles for heavy guns with
gas checks so arranged as to prevent or diminish the erosive effect of the explo-
sion of heavy charges.
The gas check according to our invention, whilst it forms a perfect check for
the gases, is not torn off by the rifling when the projectile is fired; the plastic
material which forms part of the gas check is guarded against deformation when
the projectile is stored on board ship or in the magazine, and it lubricates the
rifling as the projectile passes along the bore.
In order to prevent the erosion in the interior of the gun which is principally
caused by the passage of the highly heated explosive gases between the projectile
and the bore, we provide the projectile near its base, behind the ordinary driving
band, with flanges made preferably of copper, forming between them grooves
charged with elastic packing and lubricating material, as we shall describe
referring to the accompanying drawings, which is a longitudinal section of one
side of the rear part of a shell provided with a gas check according to our
invention.
In Fig. 1a is part of the gun shewing the profile of the internal surface of
the bore and the charge chamber c. The projectile has on its rear part
the driving band d which is of the usual kind for taking the rifling, but, accord-
ing to our invention, is made with a rearward extension e from which project
several flanges f having their intervals charged with lubricating material g
protected by a thin sheet metal covering band h. The flanges f are compara-
tively thin so that, while they give sufficient support to the packing it requires
comparatively little force to make them take the rifling, and any one can fold
backwards when it meets with excessive resistance, so that none of them is likely
to be torn off during the passage of the projectile along the bore.
The flanges are preferably of such diameter that, when the projectile is pushed
home, the rearmost flange comes first in contact with the interior surface of the
chamber and is bent somewhat back before the flange in front of it meets the
surface of the chamber. The rear flange is preferably made in the first instance
with an inclination rearwards. In this manner there is obtained a perfect piston
fit of the flanges and the plastic material between them, when the projectile
is pushed by the rammer, and, when the charge is fired, the rear flange is caused
to fit still more tightly by the pressure of the explosion gases.
The packing material placed in the grooves between the flanges consists pre-
ferably of asbestos saturated with wax, plumbago or other suitable lubricant.

page_text: The covering band h may be dispensed with, but it is useful for protecting
the packing and flanges during the handling or storing of the projectiles.
Although we have shown in Fig. 1 the extension e as made in one piece
with the driving band d, it might obviously be a separate ring put on in the
same way as the driving band as f shewn in Fig. 2, in which instead of several
flanges, only one fitting the bore is shewn.
The gas check is obviously applicable to solid shot as well as shell.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
A gas check for a projectile consisting of a ring fixed on the projectile behind
the driving band and having one or more projecting flanges with plastic packing
of lubricating character in the intervals between the flanges substantially as
and for the purpose set forth.
Dated this 25th day of January 1000
ABEL & IMRAY,
Agents for the Applicants.