Improvements in or relating to Pneumatic Cannon.
Year: 1891

page_text: Date of Application, 27th Feb., 1891
Complete Specification Left. 16th Oct., 1841-Accepted, 24th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pneumatic Cannon.
A communication from HENRY EICHBAUM, of the Grand Hôtel du Louvre,
Boulogne-sur-Mer, in the Republic of France, Engineer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., do hereby declare the nature of this invention to be as follows:-
-
This invention relates to that class of ordnance in which the projectile is
discharged by the admission behind it of compressed air or gas. Hitherto these
guns have been arranged pivotted upon trunnions placed at or near the breech
end of the gun, or between that and the centre. These guns have necessarily very
long barrels usually about fifty feet in length, one of the consequences of which
construction was that being usually fired at a high elevation the muzzle of the gun
projected extensively thus offering a good target for the enemy's fire and enabling
him readily to locate the exact position of the gun.
I seek to overcome this and other drawbacks attendant upon the previous con-
struction by pivotting the gun at the muzzle end instead of at the breech end, not
necessarily close to the muzzle as I might easily carry the trunnions back several
fect but however they may be precisely placed they would always be between the
muzzle and the centre instead of as hitherto between the breech and the centre.
One very important advantage of this is that the long projecting barrel hitherto
displayed is retained entirely within the walls of the fort or sides or turrets of the
vessel, elevation of fire being obtained by lowering the breech rather than by
raising the muzzle.
As regards the mechanical details of this arrangement it will readily be seen
that these may vary very materially without departing from the spirit of the
invention but I will describe some ways in which this construction of gun may be.
accomplished. The gun having its trunnions at or near the muzzle the compressed
air or gas would be introduced through these trunnions and carried back to the
breech by means of one or more external pipes or by a passage or passages or
jacket partially or completely surrounding the gun tube, rigidity and strength being
secured by suitable bracing, tying or trussing in connection with or in addition to
the said pipes passages jacket or means employed for conveying the pressure from
the muzzle to the breech.
The elevation or depression of the breech may be accomplished by means of one
or more hydraulic or other rams or pistons connected either directly or indirectly
with the barrel and arranged upon or in connection with a suitable training carriage
A direct
and arranged as much as possible below the level of the gun barrel.
connection between the rain would consist of a simple link or connecting rod and
an indirect one could be a series of links or levers or an arrangement of multiple
pulleys and chains or bands. Another way of raising or lowering the gun would
be to allow the breech to rest upon a segmental platform adapted to be raised or
lowered by any of the means above described.
One means of supporting the gun would be the employment of one or more
sectors or quadrants in which a guide block or cross head upon or connected with
the gun 'slides, the said cross head or equivalent having the requisite movement
imparted to it by the before described rain or rams by a rack and pinion, by levers,
chains, or other suitable device.
The carriage would be arranged to work horizontally upon any suitable platform
upon which it could travel in any required direction under the influence of any
suitable form of power whether inanual or otherwise. It will be understood that
the carriage spoken of above may be of any required construction and in one or
D

page_text: more parts or even more than one independent carriages may be employed and
these may be arranged and constructed so as particularly to provide for the requisite
stability of the gun.
Where it is not desired to convey the pressure to the breech of the gun by
means of pipes or passages from the trunnions this may be accomplished by securing
upon the gun itself a reservoir which can be charged as required by means of a
flexible pipe or by bringing it to a suitable connection, of the carriage or other-
wise or by any suitable arrangement of flexible or adjustable piping connected
either with the said reservoir or directly with the valve chamber of the gun. Or
a reservoir may be carried on the gun in which the pressure is obtained by the
explosion of suitable powder in cartridge or other form.
Dated this 27th day of February 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant."
COMPLETE SPECIFICATION.
Improvements in or relating to Pneumatic Cannon.
A communication from HENRY EICHBAUM, of the Grand Hotel du Louvre,
Boulogne-sur-Mer, in the Republic of France, Engineer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., 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 relates to that class of ordnance in which the projectile is
discharged by the admission behind it of compressed air or gas.
Hitherto these
guns have been arranged pivotted upon trunnions placed at or near the breech end
of the gun, or between that and the longitudinal centre of the barrel. These guns
have necessarily very long barrels usually about fifty feet in length one of the con-
sequences of which construction was that being usually fired at a high elevation the
muzzle of the gun projected extensively thus enabling the enemy to readily locate
the exact position of the gun and offering a good target for his fire.
1 seek to overcome this drawback attendant upon the previous construction by
pivotting the gun at the muzzle end instead of at the breech end, not necessarily
close to the muzzle as I might easily carry the trunnions back several feet but
however they may be precisely placed they would always be between the muzzle
and the longitudinal centre of the barrel instead of as hitherto between the breech
and the centre, the object of such arrangement being the entire concealment of
the position of the gun. It is evident that the greatest advantage in this respect
would accrue by placing the trunnions of the gun as near the muzzle as practicable,
as in that case no part of the gun would appear above the rampart which would
also be so low as not to attract attention from a distance. By this arrangement the
long projecting barrel hitherto displayed is retained entirely within the walls of
the fort or sides or turrets of the vessel, elevation of fire being obtained by
lowering the breech rather than by raising the muzzle.
As regards the mechanical details it will readily be seen that these may vary
very materially without departing from the spirit of the invention but I will
describe some ways in which this construction of gun may be accomplished. The
gun having its trunnions at or near the muzzle the compressed air or gas would be
introduced through these trunnions and carried back to the breech by means of one
or more external pipes or by a passage or passages or jacket partially or com-
pletely surrounding the gun-tube, rigidity and strength being secured by suitable
bracing tying or trussing in connection with or in addition to the means employed
for conveying the pressure from the muzzle to the breech.
The elevation or depression of the breech may be accomplished by means of one

page_text: or more hydraulic or other rams or pistons connected either directly or indirectly
with the barrel and arranged upon or in connection with a suitable training carriage
and as much as possible below the level of the muzzle pivot. Any other suitable
means may however be employed for the purpose of elevating or training the gun.
Where it is not desired to convey the pressure to the breech of the gun by
means of pipes or passages from the trunnions this may be accomplished by securing
upon the gun itself a reservoir which can be charged as required by means of a
flexible pipe or by turning it to suitable connection with a fixed supply or by any
suitable arrangement of flexible or adjustable piping connected either with the said
reservoir or directly with the valve chamber of the gun. Or a reservoir may be
carried on the gun or its supports in which the pressure is obtained by the
explosion of suitable powder in cartridge or other form as set forth in the Specifi-
cation to Letters Patent granted to me No. 2868 dated 22nd February 1890.
In the accompanying drawings:
:-
Figure 1 is a sectional elevation, and Figure 2 a plan showing an arrangement of
the muzzle pivotted gun.
Like letters represent like parts throughout the drawings.
A represents the barrel of the gun which in the drawings is shown pivotted quite
close to the muzzle A'. The pivotal mechanism, the supporting pintle, pipes, and
compressed air reservoirs would preferably be arranged in a manner similar to that
described in my previous British Specification No. 6369/89; for present purposes
it will be sufficient to say that the compressed air or gas is supplied to the gun
through trunnions B arranged one at each side of the muzzle and thence conveyed
as already explained to the breech end of the gun, the drawing representing a
hollow casing or a large tube outside the gun barrel for this purpose. The pintle,
reservoirs etc. may be arranged in any convenient manner within the masonry, earth
or rock of the fortress or other station where the gun is placed. C represents the
breech which may be raised to the level of the projectile D shown supported upon
a suitable carriage E and adapted to be inserted in the gun tube by manual or other
power. The projectile carriage E is adapted to run upon a circular track E
whose centre would be at the pivot of the gun so that when the breech of the gun
is raised to the level of the carriage (which would preferably be such that the axis
of the projectile would be in the same plane as the axis of the gun when lying in
a horizontal plane) the latter may be run round so as to bring the projectile
opposite the breech of the gun wherever that may at the moment happen to be.
The gun is shown in its horizontal or elevated position for loading in dotted lines
in Figure 1.
For the reason already mentioned that the gun is usually fired with the muzzle
elevated and also to avoid presenting a mark to the enemy, it would probably
seldom happen that the breech would require to be raised above the muzzle and
the arrangement illustrated herein is therefore such as would be chiefly suitable for
moving the gun up to a horizontal plane only; nevertheless I wish it to be under-
stood that the mechanisin may be arranged to elevate the breech just as high above
the muzzle as may be desired as for example when the gun was mounted in a high
and commanding position and had to fire downwards instead of upwards.
The elevating mechanism is shown in the drawings particularly in Figure 1, as
consisting of a hydraulic ram F working in an oscillating cylinder G supported on
a training carriage H running upon a circular track so that the gun may be trained
around its centre of motion at the trunnions B. The hydraulic pressure to the
cylinder G may be supplied through the pipe G1, from a supply carried through
the pintle.
The gun may be trained around the pintle by movement imparted to the
carriage H which with its flanged wheels I (preferably one fixed and one loose
upon each shaft J) runs upon rails K arranged circularly around the centre of the
pintle L so that the gun moves radially around the said pintle centre. The training
carriage H may be caused to travel upon the rails K in any suitable manner as by

page_text: manual power pulleys and chains rack and pinion mechanism or by other convenient
means.
Probably the arrangement shown in Figures 1 and 2 with the trunnions very near
the muzzle would be sufficient for practical purposes but it will be understood that
the trunnions may be placed close up to the muzzle if desired.
Where the gun was set to fire always at the same vertical angle the raising and
lowering apparatus such as the cylinder G and rain F would not be required and
the loading arrangements would permit of the projectile being inserted with the
gun at that angle; the training carriage could be retained and the variation in
range would be secured by varying the quantity or intensity of the charge which
expelled the projectile. As shown in the drawings the gun is capable only of
being trained around the pintle for a portion of the complete circle, but this is
merely a matter of arrangement dependent upon circumstances and the gun may
revolve completely around the pintle or support if required.
Having now particularly described and ascertained the nature of the said
invention, as communicated to me by my foreign correspondent, and in what manner
the same is to be performed I declare that what I claim is :-
1. In a pneumatic canson pivotting the tube or barrel on the muzzle side of its
longitudinal centre substantially as and for the purpose described.
2. A pneumatic cannon pivotted at or near the muzzle substantially as and for
the purpose described.
3. A pneumatic cannon pivotted on the muzzle side of its longitudinal centre
and having the breech end supported upon a training carriage or equivalent and
provided or not with elevating mechanism and adapted to be moved about said
pivot substantially as and for the purpose described and illustrated in the accom-
panying drawings.
Dated this 15th day of October 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant.