Improvements in Cannons or other Apparatus for Discharging Projectiles by Means of Air or Gaseous Pressure.
Year: 1887

page_text: Date of Application, 14th Sept., 1887
Complete Specification Left, 14th June, 1888
Complete Specification Accepted, 14th Sept., 188
Improvements in Cannons or other Apparatus for Discharging
Projectiles by Means of Air or Gaseous Pressure.
I THOMAS WHITAKER, of Horsforth, near Leeds, in the County of York Contractor,
do hereby declare the nature of this invention to be as follows :-
This invention has for its object an apparatus for discharging projectiles by means
of compressed air, or possibly, in rare cases, by compressed carbonic acid gas, either
pumped by hand into the apparatus, or supplied from a reservoir on board ship,
or in the fortification or other place where the apparatus is used, or a combination
of these, namely, a hand apparatus pumping a maximum pressure from a reservoir
already charged to a medium pressure. For warlike purposes, however, in any
case besides the general reservoir of air pressure a special pumping apparatus
will be attached to each cannon or gun, so that in the event of accident to
the pumping apparatus worked by the engines, hand pumping apparatus can
be used.
The cannon itself will be composed first of the barrel proper in which the projectile
is placed, either in the breech loading manner or muzzle loading as preferred. In
a conical seating in the end of the barrel proper the end of a plunger is seated.
This plunger is surrounded by a very strong cylinder allowing, however, an air space
to surround the plunger of say one third the diameter of the projectile, though of
The
course the dimensions can be varied to suit the particulars of each case.
cylinder has a gland and packing round the plunger so as to prevent escape of air.
The plunger is preferably for a large portion of its length made hollow, so as to be
as light as practical, so that it can be more easily driven backwards and forwards and
thus entail less wear and tear and strain upon the gun or apparatus. By having the
plunger hollow, also, I can if desirable perforate its sides & thus use a larger quantity
of air. The end of the ram has a piston attached to it working in another cylinder,
which cylinder is rigidly connected to the ram cylinder by means of a strong
metallic strap. This cylinder is provided with ports and valves by whicli

page_text: means the air pressure can be thrown onto either side of the piston as required,
and also with a pet cock, or other valve, to work by hand, or otherwise, to let
off the air from the back of the piston when the gun or apparatus is to be
discharged.
The mode of action is as follows. The compressed air is let into the back of the
piston, driving the plunger firmly up to its seat. A projectile is now driven into the
barrel firmly up to the plunger head. The compressed air is let into the larger
cylinder surrounding the plunger. When the gun or apparatus is to be discharged
the compressed air is withdrawn from the back of the piston and let onto the front
of the piston simultaneously this at once causes the piston to fly back against the back
of the end cylinder, where if desired it can be cushioned by a little of the air still
left in. This flying back of the piston and the plunger leaves an annular opening
from the main cylinder into the barrel immediately behind the projectile which is
instantly driven out of the gun with the force of the highly compressed air behind it.
The valves are now reversed, the air pressure introduced behind the piston and
let out of the front of the piston driving the plunger back into its seat. Fresh
compressed air is admitted to the main cylinder and the operation is performed
afresh.
When used on shipboard or in a fortress, and supplied from pumping apparatus
from the main engines; the supply from the pumping engine is caused to pass
direct to the ram cylinder. If however an accident happens to the main pumping
apparatus which is connected with a flexible pipe to the rain cylinder, a disconnection
is made and a hand pump can be used in its place.
In order to supply the air under pressure to a gun which will recoil on being
discharged, and is consequently not a fixed object, the air pipes are connected to the
side of the gun, or the hand pump attached thereto by means of pipes jointed by
universal pipes, or in rare cases, where the apparatus is always to fire in one direction,
stuffing boxes and long cylinders can be used."
Dated this 12th dor of Santambo. 1807

page_text: Projectiles by Means of Air or Gaseous Pressure.
I, THOMAS WHITAKER, of Horsforth, near Leeds, in the County of York, Contractor
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 object of this invention is to provide a gun or apparatus for discharging
projectiles by the pressure obtained from compressed air or other elastic fluid.
It is designed chiefly for cannons throwing heavy explosive projectiles or shells but
may be employed in connection with smaller guns.
It consists essentially in forming the cannon with a chamber or reservoir for the
compressed air, through which moves one end of a double plunger or ram acting as a
piston valve to control the passage of the compressed air, the other end of the plunger
working in a separate cylinder and held in position against its seat by the force of
compressed air admitted behind it.
Referring to the accompanying drawings
Fig. 1, is a side elevation.
Fig. 2, a longitudinal sectional elevation of canon constructed in accordance with
the invention.
Fig. 3, sectional elevation of back end of gun showing modified arrangement with
cylinder F formed in one with the gun.
Fig. 4, transverse sectional elevation of breach on line a. a.
The barrel A of the cannon may be constructed in any ordinary manner, either
breach loading or muzzle loading, preferably the former as shown. At the back end
the barrel is strengthened by a casting B of bronze or steel or other metal. This
casting surrounds the barrel A for a portion of its length and extends back beyond it,
and in it behind the barrel is formed a chamber or reservoir C, opening into the
barrel, to receive the charge of compressed air for discharging the projectile.from
the gun. The air or charge chamber C terminates at the back in a cylinder or is
fitted with a suitable gland or stuffing box in which a ram or plunger D works passing
forward through the air chamber C to a seating a at the end of the barrel A forming
therewith a valve to control the passage of air from the chamber to the interior of
the barrel. The ram or plunger D is preferably made hollow as shown to render it
as light as possible and easily worked. The space of the plunger D may if
required be utilized as, or to form part of, the reservoir for the compressed air, if the
chamber C is not found sufficiently large or it is desired to reduce it in size. To the
other end of the plunger D a second piston or plunger E is connected which works
in a cylinder F. to which compressed air is admitted at one end to force or hold the

page_text: plunger D against its seating at a. The cylinder F is rigidly connected to the gun
by means of a strong metallic strap G or otherwise. The strap G is jointed at g and
by unscrewing the bolts the cylinder F may be removed when it is desired to take
out the plunger D to examine or repair it. Instead of a cylinder F detached as shown
in Figs. 1 and 2 the cylinder may be formed as part of the back of the gun. In
Fig. 3 the plunger E works in the cylinder F the end of which is closed by a door
or lid F to which the valve is secured. In the air chamber C slides or guides H are
fitted for the plunger D to slide on. At each joint or seating packings of leather or
other material I are inserted to prevent the escape of air. J, J are glands or
stuffing boxes to prevent escape of air and K piston rings for the same purpose.
In the end of the plunger E is inserted a stud L to protect the washer I when the
plunger is driven back against the end of cylinder. The compressed air is admitted
to the chamber C through the port c and to the cylinder F through the port ƒ from
the supply pipes P fitted with the valves or cocks p, p, p. The air will be compresed
by any suitable apparatus and stored in an accumulator or receiver for use or may be
pumped direct into the chamber of the gun.
The breach through which the projectile is admitted is formed in the side of the
gun and may be closed by a movable lid M. held in position by cotters N driven
through the flanges band behind which are driven the taper wedges O. Instead of
this arrangement a hinged lid with screw attachment or other arrangement
of breach may be employed. Q is the trunnion of the gun and T a pressure
gauge.
In firing the cannon the action will be as follows:-The compressed air will be
admitted to the pipes Pat R and the valve p¹ first opened through which the air will
pass to the cylinder F and drive the plunger D tightly against its seating at a and the
valve again shut. The projectile S will then be placed in position against the end
of the plunger D, the valve opened, the charge of air admitted to the chamber C
through the port e, and the valve shut. The gun is thus charged and in readiness for
firing which is done by opening the valve p through which the air in the cylinder F
escapes relieving the pressure on the end of the plunger. The end of the plunger D
is made to project slightly above its seating a so that when relieved of pressure at F
the pressure of air in the chamber C acting on the end of the plunger moves it
back and allows the full force of the charge to be directed against the projectile.
When the gun is constructed to recoil with the discharge a flexible pipe may be
attached at or pipes otherwise fitted to allow for the movement.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. A cannon or other apparatus for discharging projectiles having a chamber, at
the back end opening into the barrel, to receive a charge of compressed air or other
elastic fluid with one end of a piston or plunger moving therein to form a valve,
the other end of the plunger working in a separate cylinder and held to its seat by
the pressure of air admitted behind it substantially as described.
2. In a cannon from which the projectile is discharged by the pressure of
compressed air or other elastic fluid the use of a plunger valve moving through the air
chamber and held to its seat by the pressure of air on its outer end substantially as
described.
3. A cannon having a double piston or plunger forming the discharge valve one
end of which passes through the compressed air chamber and is seated against the end
of the barrel and the other works in a subsidiary cylinder the piston being held to
its seat by the pressure of air admitted to the subsidiary cylinder and withdrawn
from its seat when the pressure is relieved from behind it by the pressure in
the charge chamber acting upon an exposed part of the plunger end substantially as
described.
4. A cannon or other apparatus for discharging projectiles having a strengthening
piece cast (or otherwise affixed) at the back end containing an air chamber

page_text: opening into the barrel, a cylinder forming part thereof or rigidly connected thereto
and a double piston or plunger working therein substantially as and for the purposes
described.
5. A cannon or other apparatus such as herein described having a plunger valve
formed hollow or with an internal chamber to be utilized for, or form part of, the
reservoir for the air charge substantially as described and shown.
6. A cannon or other apparatus for discharging projectiles by the force of
compressed air or other clastic fluid constructed and arranged substantially as described
and shown.