Improvements in or relating to Pneumatic Guns.
Year: 1889

page_text: Date of Application, 13th Apr., 1889
Complete Specification Left, 28th Nov., 1889-Accepted, 11th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pneumatic Guns.
A communication from HENRY EICHBAUM, of Hotel Meurice, Calais, 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 which may be termed the Aerial torpedo pneumatic gun is intended
more especially for cannon adapted to throw large projectiles containing high
explosives, and in which air under high tension is used as the propelling force but
it may be carried out with a wide range of sizes and may serve with other gases
than atmospheric air, and the pressure may be produced by other means than
mechanical compression. The objects sought to be obtained in this invention are
simplicity and economy of construction and certainty and effectiveness of operation.
Throughout this specification the word "firing" is used in its technical sense as
used by artillerists to define the act of discharging the gun although in this gun
there is no ignition of powder or other explosive. The word "air" is used to
designate the large volumes of air or other elastic gases confined under heavy pressure
employed to impel the projectile, and the word "oil" to designate the fluid which is
used to pack the joints, though glycerine or various other fluids may be substituted.
The main tube or barrel of this gun instead of being hung or supported as has
hitherto been the case at the breech is supported upon trunnions a considerable
distance from the breech but not so near the muzzle as to interfere with the
preponderating weight of that end of the tube which is required for the satisfactory
working of the gun. The air pressure is contained in a reservoir or series of
reservoirs preferably disposed underneath the gun carriage and which may consist
of a series of tubes closed at one end. and communicating with the main channel
or pipe by which it is conveyed to the gun. These reservoirs are preferably
disposed in opposing sets, whether two or more complete sets are employed being
immaterial, the object being to balance them as completely as possible while there
is the additional advantage that being oppositely disposed they can be tied together in
a secure and effective manner. The gun carriage is centred upon a hollow centre or
pintle closed at both ends the hollow interior being in connection with the reservoirs
the inlets through which are arranged opposite each other, again with the object of
balancing the pressure, shocks or strains. Suitable peripheral openings are provided
in the upper part of the pintle through which the air passes sideways so as to avoid
unnecessary strains. From the pintle the air passes to a yoke or chamber sur-
rounding the pintle and provided with opposing passages which convey the pressure
to the side tubes of the gun each of which carrying at one end a trunnion
terminates at the other at or near the breech of the gun in a valve box. The
trunnion boxes are carried upon suitable brackets conveniently disposed upon the
gun carriage. The breech of the gun is closed by any suitable form of valve or
equivalent which will allow of the entrance of the projection and can be conveniently
and sufficiently tightly closed when required, but I prefer to employ a sliding valve
having a slot with which engages a projection upon a hand lever by which it is
operated. The projectile is supplied from any suitable form of carriage. The gun
carriage may be of any convenient construction provided underneath with rollers to
travel upon a circular path the carriage being preferably revolved by means of a
multi-cylinder hydraulic engine secured upon the carriage itself and working a gear
wheel engaging with an internally toothed ring, the engine being operated by
hydraulic or other suitable pressure which may be conveyed by one or more passages
distinct from the air passage up the central pintle. The elevation of the gun is

page_text: preferably accomplished by means of a hydraulic cylinder pivotted to the carriage
and having a plunger or piston rod pivotted to the gun barrel or to a truss or framing
which is preferably provided as a support for it. The samo fluid pressure which
operated the hydraulic engine above described may be employed for this cylinder also
and the regulation of the pressure may be effected by any convenient arrangement
of levers, valves or equivalent.
Some of the more important features of this invention relate to the valves for
regulating the admission of the air to the gun barrel and to the packing of the joints
and I will first describe the arrangement and operation of the valves:The air
pressure as already described is conveyed by the side tubes to the valves at the breech
of the gun and it will be understood that the pressure being exceedingly severe,
generally a thousand pounds to the square inch, and the valve which is of considerable
dimensions proportionate to the requirements of the gun requires to be opened a
certain distance to give the requisite passage area but must also be closed so quickly
as to be open for an almost inappreciable length of time, say from the tenth to the
hundredth part of a second being found in practice to give satisfactory results
according to the range required. It will be understood that the variation of range is
chiefly effected by the length of time during which the firing valve is open; and it
will thus be seen that the proper action and complete regulation of the firing valve is
of the utmost possible importance to the proper working of the gun. In providing
then a valve possessing the necessary requirements it is necessary to provide two
valves, one the large firing valve proper and the other a smaller valve to operate the
larger valve. In the gun I am describing two firing valves are employed chiefly with
the object, upon which stress has already been laid, of neutralizing the shock by
opposing them the one to the other and in this case both these firing valves are
operated from the one controlling valve so that the operation of the two firing valves
practically simultaneous. Describing now one of the firing valves I prefer to make
it circular with a face towards the gun barrel fitting upon any suitable form of bed or
seat. The valve is hollow and having a cylindrical body externally smaller in
diameter than the valve face at one end and the flange or disc which it carries at the
other and which acts as a piston in a short cylinder provided in the casing. A portion
of the hollow interior of the valvo is filled with any suitable form of comparatively
soft packing for the purpose of deadening the shock occasioned by the movement of
the valve and when the valve is opened to its full extent this packing comes in contact
with a stop projecting into the interior of the valve and adjustable preferably by
means of a screw passing to the exterior of the casing and adapted to be turned by
any convenient means, this spindle preferably carrying an indicator by which the
exact position of the stop may be ascertained. The valve piston is in its normal
condition subject to equal air pressure upon both sides and is of slightly greater area
than the face of the valve so that upon the pressure at the back of this piston being
withdrawn or diminished the pressure upon the other side of the piston will so far
exceed the pressure tending to retain the valve upon its seat that the valve shall be
promptly removed from its seat. The object then to be attained in operating this
valve is to withdraw or diminish the pressure upon the back of the piston momentarily
and instantly replace it; this is accomplished by means of the controlling valve which
I will now describe.
This controlling valve is also practically two valves both cylindrical the first one of
considerably smaller diameter than the firing valve and whose function is to momen-
tarily cut off the supply of air to the back of the firing valve and restore it, and the
small valve which I will term the hand-valve as that is operated directly from the
hand of the person working the gun. The controlling valve is a piston valve and
normally subject to pressure upon both sides so that upon the pressure upon one side
being withdrawn or diminished the valve will be moved and the function of the hand-
valve is to relieve the pressure upon one side of this piston and instantly to restore it.
The controlling valve is in many respects similar to the firing valve but as already
stated smaller, it has a hollow interior provided with packing which comes against a
stop when the valve has reached the extent of travel allotted to it. One end of this

page_text: valve carries the piston already mentioned and the other carries the valve proper
which is a piston valve. The casing or cylinder in which this valve reciprocates is
provided with two annular recesses one in connection with a constant supply of air
pressure and the other communicating with the back of the piston of the firing valve.
When the controlling valve has been moved to that portion of its cylinder between
the two annular recesses it will be understool that the connection between the two
recesses is cut off consequently the continuous pressure in the one can no longer pass
by the other to the back of the firing valve and to enable the firing valve to be lifted
from its seat all that is required is to open a connection between the second annular
recess and the atmosphere and this is accomplished by allowing the controlling valve,
which is preferably provided with considerable lap, a sufficient travel. In its open
position therefore the controlling valve stands between the two annular recesses the
second of which is in direct communication with the atmosphere.
The hand valve which is also preferably cylindrical is arranged in a suitable casing
one end of it resting upon a bed or seat and the other end fitting sufficiently closely
in an opening provided for it in the solid portion of the casing. This valve which is
hollow terminates in a recess in communication with constant pressure and suitable
holes or passages are provided in it by which the pressure can pass from the interior
of the valve to a hollow portion of the casing which is in communication with the
back of the piston of the controlling valve. The openings in the hand-valve are so
arranged that they can be moved into the close fitting portion of the casing and are
thereby closed. The operation is as follows:-Normally the hand-valve rests upon its
seat, being held there by the pressure and the openings in the valve providing
communication between the interior of this valve and the back of the controlling
valve piston. As however this valve is of comparatively small size and sufficient
leverage can be provided the operator is enabled to force it from its seat against
the pressure. This movement effects two objects; firstly, it moves the holes in the
hand-valve into the closed portion of the casing and thereby cuts off the communication
between the constant pressure and the controlling valve, and second by removing the
valve from its seat it opens direct communication between the back of the controlling
valve piston and the atmosphere. The consequence of this is that the front of the
controlling valve piston being by the arrangement and shape of the valve in com-
munication with the first of the annular recesses which is subject to constant pressure
and the piston being of larger diameter than the valve proper the whole of this valve
is promptly moved to its open position with the result that the connection between
the two annular recesses is closed and the connection between the back of the firing
valve piston and the atmosphere is opened. The firing valve is thus opened. The
instantaneous closing is effected as follows:-In connection with the spindle of the
hand-valve is a trigger having a jaw or ring surrounding the spindle of the controlling
valve and the action is that when the controlling valve moves it this trigger releases
the hand-valve from the control of the operator the pressure instantly closes the hand
valve restoring the pressure to the back of the controlling valve and thus returning
it to its normal position with the result that the back of the firing valve being now
again in communication with the constant pressure the firing valve also is instantly
closed.
The length of time during which the controlling valve remains open is determined
by the position of a regulating cock provided with an external indicator by which
its position can be determined; the opening covered by this cock being preferably
carried to a point at one part so that the amount of opening may be regulated to a
Licety. It will thus be seen that if this regulating cock he wide open the controlling
valve will be returned to its seat the very instant the trigger has slipped, that is
to say in fact as soon as ever it has been opened but if this cock be entirely closed the
controlling valve would never return to its seat at all; therefore the movement of the
controlling valve can be absolutely regulated by this cock. The trigger is preferably
provided with a spring to keep it always up to the stop on the spindle of the
controlling valve.
The packing arrangements for the various working joints especially those around

page_text: annular recess.
the centre pintle and the trunnions may be constructed as follows; and I will describe
them as applied to the pintle :-The yoke which surrounds the pintle is provided with
two annular recesses one above and the other below the peripheral openings in the
pintle already described in each of these recesses the bottom of which is preferably
rounded is placed a hydraulic cup leather or other suitable packing ring upon
which rests a perforated metallic distance ring. Upon this is a second cup leather
packing ring reversed and upon this another metallic ring recessed to receive the cup
leather and connected by suitable distance pieces with a similar ring in the second
This ring is also hollow and receives a cup leather upon which is
another perforated ring and upon this again another inverted cup leather this system
of packing rings being made secure by a gland fitting into one of the annular
recesses and secured by bolts or equivalent in the usual manner. Each of these
annular recesses is in communication with fluid, preferably oil under pressure which
is in excess of the permanent air pressure so that while the air is seeking to escape
around this packing the oil is seeking to enter in the same direction and as the oil
pressure is in excess of the air the consequence is that it is impossible for the air to
pass. The pressure upon the oil or other fluid may be advantageously obtained by
means of a differential cylinder provided with a double piston the area of that portion
of which rests upon the oil being less than that of the portion which is in permanent
communication with the continuous air pressure existing in the air passages of the
gun the difference in area between these two pistons or two portions of the same
piston may be whatever is requisite but about 10 per cent. is considered to be
sufficient; this arrangement has the advantage that no matter what variation may
occur in the continuous air pressure the pressure upon the oil which constitutes the
opposing force is always to the same amount proportionately in excess of it.
In the foregoing specification I have somewhat minutely described many portions
of this invention but it will be understood that all the portions of this apparatus may
be modified, many of them considerably modified without departing from the spirit of
the invention.
Dated this 13th day of April 1889.
COMPLETE SPECIFICATION.
Improvements in or relating to Pneumatic Guns.
A communication from HENRY EICHBAUM, of Hotel Meurice, Calais, 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 :-
The invention is intended more especially for cannon operated by compressed air of
high tension and adapted to throw large projectiles containing high explosives, but it
may be carried out with a wide range of sizes and may serve with other gases than
atmospheric air; it is immaterial how the pressure of the gas is obtained.
Throughout this specification and in the claims the word " firing" is used in its
technical sense as used by military men to define the act of discharging the gun,
although in this gun there is no ignition of powder or other combustible. In this
specification and claims the word "air" is used to designate the gas of whatever kind
under pressure employed to impel the projectile, and the word "oil" to designate the
liquid employed in small quantities with an excess of pressure in the packings,
although various other liquids such as water may be substituted for oil.
What is considered the best method of carrying out the invention is fully described
below, and illustrated in the accompanying drawings of which there are seven sheets.
Fig. 1 represents the gun and the mechanism for operating it in side elevation,
with the loading carriage in position to introduce a projectile.

page_text: g. is a plan of the gun with heading carnage,
are not shown.
Fig. 3 is a plan of the air reservoirs.
Fig. is a plan of the gun carriage, showing the elevating ram, the motor for
training the gun and the yoke from which the trunnion blocks are removed to show
the position of the air passages.
Fig. 5 shows an end elevation of the gun carriage with the trunnion blocks thereon
resting on the pintle.
Fig. 6 shows an elevation partly in section of the pintle and Fig. 7 is a plan
the same, a small part being shown in section on the broken line x x in figure 6.
Fig. 8 shows an elevation one half being in section of the hollow central support
hereinafter called the pintle and the yoke the section being made through one air
nozzle of the pintle and one air passage of the yoke, the section being made on the
line y y of figure 9 which shows a plan of the yoke.
Fig. 10 is a side elevation of one trunnion block.
Fig. 1 shows an elevation partly in section of the barrel of the gun, the trunnions
thereof, the yoke and a portion of the pintle and one trunnion block; the other
trunnion block and one trunnion not being in section. This view is taken from the
rear of the gun.
Fig. 12 is a plan of the parts shown in fig. 11, one half being in section through
the axis of the gun.
Fig. 13 shows the special packings used for securing the joints between the pintle
and the yoke against the passage of air, the view being a vertical section of portions
of the pintle and yoke. This figure is shown as being connected by pipes with
figure 15 which is an elevation partly in section of the differential cylinder used for
producing pressure on the packings shown in figure 13. Fig. 14 being a plan of a
portion of the packing called the double distance ring which is shown in elevation in
figure 13.
Fig. 16 is a plan one half being in section of the gun barrel from the trunnions to
the breech showing also the trunnions the side pipes the firing valve chambers and
the breech block. A projectile ready for firing is shown in the barrel and the breech
is shown closed.
Fig. 17 is a view in elevation of the breech block the gate being closed as shown
in figure 16.
Fig. 18 is the same except that the gate is here open for the introduction of a
projectile into the barrel.
Fig. 19 is a side elevation of the parts shown in figure 16.
Fig. 20 shows the manner in which the ducts in the pintle for the conveyance of
the motive fluid for elevating and training the gun, being stationary, are connected
with the controlling valves which rotate with the
gun.
Fig. 21 is a plan partly in section of that portion of the barrel to which are
attached, the firing valves, the pipes which connect them to the auxiliary valve chest
and the chest itself as bolted to a suitable seat on the barrel.
Fig. 22 is an end elevation partly in section of the parts shown in figure 21 with
the auxiliary valve mounted on the chest.
Fig. 23 is a side elevation of the parts shown in figures 21 and 22.
Fig. 24 is a horizontal section through the centre of the auxiliary valve cylinders
showing the two valves in their closed position.
Fig. 25 shows the same except that in this view the valves are open.
Fig. 26 shows a vertical section of the auxiliary valve chamber in side elevation
the valves being removed, this view being intended to show the air passage from the
two air-belts to the auxiliary valve chest. It also shows a vertical section of the
regulating cock.
Fig. 27 is an end elevation of the auxiliary valve chamber and regulating cock and
fig. 27 is a sectional elevation of a portion of figure 27.
Fig. 28 is a cross section of figure 25 without the fittings.
Fig. 29 is a side view of the valve rod which appears in plan in figure 25.

page_text: occur.
omnar letters of reference indicate the same parts in all the figures where they
Referring to figure 1 A designates the pintle which is the fixed centre around
which the gun is trained. It is securely fastened by bolts to a substantial foundation
as shown. It is represented in several of the drawings, but its construction is clearly
shown in figs. 6, 7 and 8. It consists of a single casting combining the following
features:-
1st, a sufficient and solid centre around which the gun is trained of ample stability
and strength to withstand the recoil of the gun. 2nd, a passage for the air under
heavy pressure from the firing reservoirs to the gun and in this respect it is
constructed so that the strains due to this pressure are self contained in the pintle, it
being closed at the top and bottom, and 3rd, it provides for the passage to and fro of
the motive fluid for training and elevating the gun, from the stationary to the
movable parts of the system. The air enters from the firing reservoirs shown in
figs. 1 and
by the two nozzles A' on opposite sides and issues from it through a
number of openings A² which being made around the circumference of the pintle the
pressure both of the entering and issuing air is balanced on all sides. To receive the
recoil of the gun the pintle is provided with a heavy flange A³ reinforced on all sides
by ribs A* extending to the base plate of the pintle. The pintle is also constructed
with ducts A* A* either cast or drilled in its solid substance for the passage to and
fro of the oil or other liquid which under sufficient pressure produced by a pump or
other mechanism is used to operate the machinery for training and elevating the gun,
A being the duct for receiving the fluid and A° the one for discharging it after it
bas performed the services required, as shown by the arrows indicating the direction
of the flow.
Encircling the upper portion of the pintle is a casing called the yoke, B figs. 1, 4
and 5 which carries the gun and carriage. Its construction is clearly shown in
figs. 5, 9 and 11. The centre opening of the yoke is bored to a working fit upon
the pintle, a strong collar B₁ being made upon it for embracing the flange A³ upon the
pintle the collar being strengthened by ribs B² B³ adapted to receive the recoil of the
gun. It is so constructed that opposite the openings A of the pintle there exists an
annular space B into which the air flows from the pintle and from this space the air
passes upward by two elbow nozzles B' on opposite sides of the yoke thus again
balancing the strain. The nozzles B terminate in wide and strong flanges Be on the
upper face of the yoke upon which are bolted the trunnion blocks C see figure 11.
The yoke is also provided with long wide flanges B' to which are securely bolted the
heavy channel bars B³ see figs. 1, 4, 8 and 11 which constitute the longitudinal
framing of the carriage. The yoke with its load is capable of turning through
complete circle around the pintle without obstructing the flow of air by this movement,
the openings in the pintle in every position of the yoke being in full communication
with the annular space B¹.
al
Securely bolted to the upper face of the yoke are the trunnion blocks (see
figs. 1, 2 and 5. Their construction is clearly shown in figs. 10, 11 and 12. Each
trunnion block consists mainly of a pipe C for conveying the air from the yoke to
the gun trunnion. This pipe is supported and strengthened by ribs and flangles c
and the whole forms a strong support for the gun barrel with all its attachments it
being especially shaped with reference to receiving the recoil of the gun and
transferring it to the parts below, viz. the yoke, pintle and carriage. To receive the
trunnions of the gun the pipes C terminate in chambers C which while bored to fit
the trunnions also allow the air to flow entirely around them by means of the annular
spaces C. The lower flange of each trunnion block besides being bolted to the
yoke B is also secured to the channel bars B at each end. The trunnion blocks are
united near the upper part by a strong bolt C to prevent their springing apart by
any strain either of recoil or other movement which may be brought to hear upon
them.
One of the important features of this invention is the means adopted to prevent
the escape of air through the working joints of the pintle and trunnions.

page_text: Ordinary cup leather packings such as are used to retain the heavy pressure of water
or other liquid in hydraulic machinery are found to be incapable of preventing the
leakage of air which passes freely through the pores of the material or finds its way
around the joint. The principle employed in this invention to prevent leakage of air
around or through a working joint, is to oppose the pressure of air seeking escape in
one direction, by a greater pressure of some liquid such as oil acting in a contrary
direction, which liquid will not readily if at all pass through the leather or other
flexible material used in the form of cup leather packing for the joint. The manner
of carrying this into effect is clearly shown in figure 13 which represents in vertical
section the joint between the pintle A and the yoke B. A being the openings in the
pintle and B the annular chamber in the yoke. To receive the special packing a
recess is provided in the yoke above and below the annular chamber. This recess is
shown without the packing in the drawings of the yoke in figs. 8, 9 and 11, being
there marked b. Similar recesses are provided in the joints of the trunnion blocks as
shown at cin figs. 11 and 12 to receive similar packings. Referring to fig. 13.
D is a U-shaped packing ring made of leather or other suitable material; it is formed
in one piece and fits entirely round the pintle at the bottom of the recess in the yoke..
D is a distance or separating ring fitting between D and another U-shaped packing
ring D similar to D but mounted in a reverse position. D³ are two distance rings.
which may be in one piece with connecting bars D₁ of which there are several and
which bridge the space between the two rings D³. Part of this ring is shown in
fig. 14 the connecting bars D* D* being there shown in section. A similar arrangement
of U-shaped packing rings D' D' with their distance ring D is mounted on top of
the double distance ring D³. To secure all these rings in position a metal gland Da
is fitted into the remaining portion of the recess the Hange of the gland being held
down to the yoke by bolts and nuts as shown in figure 13 at D also in fig. 8 where
the whole diameter of the gland is shown. A perforated cylinder or ring or other
equivalent means may be used instead of the double distance ring D³ D*.
Under this arrangement the air under the heavy pressure in the pintle and yoke
would easily find its way by the joint, but to prevent this, oil or other dense liquid
such as glycerine is introduced into the spaces between each pair of U-shaped packing
rings which spaces are maintained by the distance rings D₁ De which as shown in the:
drawing are thinner than the width of the recess, thus leaving a space on each side of
them, cominunication between these spaces being made by holes at intervals through
each ring as shown at d d. Although it is preferable to use the distance rings D¹ B..
the packing rings D D or D D7 can be maintained apart by other means.
Means are provided for filling these spaces with the oil or other liquid at a greater
pressure than the air in the spaces of the gun as follows;-Fig. 15 represents a
cylinder E of two different internal diameters and a piston E' fitting in both parts.
The space E above the piston is connected through the nozzle E³ by means of a pipe
or pipes with a part of the apparatus in which the air is at the firing pressure, (the
interior of the yoke being a convenient place for the purpose as shown by the dot and
dash lines connecting the yoke to the nozzle E³) so that the upper face of the piston
is always under that pressure no matter how much the pressure may fluctuate. A
sufficient quantity of oil is always kept above this piston to constitute a hydraulic
packing. The lower part of the cylinder E is of less diameter than the upper and is
filled with oil or other liquid and connected by suitable pipes E5 and by holes E made.
for the purpose the oil is led to and fills the spaces between the packing rings D D..
and D D' obtaining access to both sides of the distance rings therein by means of
the holes d. About 10 per cent. excess of hydraulic pressure above the air pressure
is found sufficient to make these packings tight; and the two parts E2 E of the
differential cylinder are accordingly made of such diameters that the area of the piston
exposed to the air pressure is about ten per cent. in excess of the area of the piston,
that presses on the oil in the lower and smaller part of the cylinder.
In illustration of the action of the two pistons, if we assume that the pressure of
the air in the firing reservoirs, pintle, yoke, trunnion blocks and other air passages
of the gun before firing is 1000 lbs. per square inch, the pressure of the liquid in the

page_text: .
lower part of the cylinder and in the packings will be about 1100 lbs. per square inch.
If after firing the air pressure falls to 900 lbs., the pressure of the liquid will be
about 990 lbs., and in either and all cases sufficient to absolutely prevent the leakage
of air through or around the joints.
+
The packings for the trunnions are the same (except as to dimensions) as those
described for the pintle recesses c being formed in the chamber of the trunnion
blocks and glands for holding the packings in position as shown in figs. 11
and 12. To supply liquid pressure to these a pipe E7 Figs. 13, and 15 is provided
to carry oil from the differential cylinder to each trunnion where it enters at the
fittings e fig. 11. The space between the upper and lower ends of the piston E¹ is
open to the atmosphere through holes only one of which is shown at e' fig. 15.
In order to render the construction of the barrel easier and incur less risk of
defects in material, the trunnions of the gun are made separate from the barrel.
In this way also they may if desirable be made of a different material from the
barrel to which they are bolted, heavy flanges being formed upon the barrel and on
each trunnion for the purpose; they are thus represented in figs. 2, 11 and 12 where
they are marked F. They are made like the pintle in the respect that both
ends are closed and strains from the air pressure are self contained. Like the pintle
also, they have openings F¹ around their circumferences through which air is admitted
to their interiors from the trunnion blocks as shown by the direction of the arrows
in figs. 11 and 12. Each trunnion is constructed with a nozzle F looking toward
the breech of the gun to which nozzles side pipes F3 are bolted leading from the
trunnions to the firing valves. Each trunnion is also formed with a palm or
flange F of such form as will receive a truss bar for supporting the barrel, these
truss bars being marked G2 in figs. 1, 2 and 12; the flanges for attachment of the
trunnions F to the barrel being marked F.
The barrel G as shown in figs. 1 and 2 is made in three sections though cases
might arise in which a less or greater number would be convenient. These
sections are bolted together to form the barrel. The rear section is constructed with
heavy flanges G₁ for receiving the trunnions see figs. 11, 12 and 16 the flanges
being reinforced by ribs to stiffen the barrel at this point. In order to support the
barrel near the forward end and also near the middle of its length the truss bars G
are secured by clamps G³ G one to each side of the barrel which truss bars
extend back to the trunnions and are bolted to them as above described. The
construction of the breech end of the barrel is shown in figs. 16 and 19 where G³
is a strong flange to which is securely bolted the breech block and Go are two
flanges to which are bolted the firing valve chambers as shown, an opening gin
these flanges admitting air to pass into the barrel when the valves are opened. The
construction of the breech block and the casing for the same is clearly shown in
figs. 16, 17, 18 and 19. The breech block itself marked H slides between heavy
flanges in the casing H' being moved either to cover or uncover the bore of the
gun by the lever H having upon it a pin with an anti-friction roller H³ which
engages the breech block in a slot h.
In the construction now being described two firing valves are shown but one such
if properly constructed would be sufficient for guns of a lesser size and more than
two might be used in very large pneumatic guns. The two valve chambers are
marked reference being here made especially to figs. 16, 19 21, 22 and 23. Each
firing valve is connected to the trunnion on its own side of the gun by pipes called
side pipes marked F³. The construction of the firing valves is clearly shown in
Figs. 21 and 22. On the left hand of fig. 21 is shown a horizontal section of the
chamber and valve and on the right hand an external view of the other valve. In
fig. 22 is shown a vertical section of the left hand valve chamber the valve itself not
being in section. J indicates the valve chambers J₁ being the nozzles connecting
with the side pipes F³. J' is the cover of each valve chamber being fastened thereto
by. bolts.
J is the valve itself the moving part, the lower face J of which is adapted to
close down tightly upon a seat J of preferably fibrous material which is held in

page_text: place by a ring clamp J' and bolts as shown. The other end of the valve is formed
into a piston J larger in diameter than J' and turned to fit accurately but easily in
that part of the valve chamber in which it is shown and intended to slide. A small
packing ring preferably of leather is fitted into a recess in this piston to make it
air tight. The interior of the valve is bored out and partially filled with preferably
fibrous material J8 which forms a buffer for the stop J' when the valve lifts from its
seat. The stop Ja is adjustable being cut with a thread into which is fitted a screw J¹
the stem of which passes through the cover of the valve, the end being squared at
to receive a wrench. All this is clearly shown in fig. 21. By turning the screw the
stop which is prevented from turning by posts J" which pass through wings upon
the stop can be screwed down upon the buffer J" so that the valve cannot open at all
or it may be screwed up toward the cover so as to allow of the full opening of the
valve, or it may be adjusted to any intermediate position. In the position shown in
figs. 21 and 22 the stop is adjusted to allow the valve to open half of the full throw
as shown by the space between the buffer and the stop. In order to ascertain the
position of the stop and thereby determine the extent to which the valve shall be
allowed to open the stem of the screw outside the cover is cut with a thread which
carries an index J12 over a scale on a standard J fastened on the cover, which scale
may be divided as finely as may be found necessary.
In order to prevent the passage of air by the stem of the screw a strong collar J1
is formed on the screw the same fitting into a recess shown on the inner side of the
cover. Between the bottom of the recess and the collar is interposed a washer of
leather or other suitable material the pores of which may be filled with paraffin or
similar compound. This being compressed by the force of the air inside the valve
chamber effectually bars the leakage of air around the stem of the screw.
The manner in which this valve J³ is opened to admit air to the barrel to propel
the projectile and closed again when desired is as follows;-The air from the firing
reservoirs passing through the pintle, yoke, trunnion blocks, trunnions and side pipes,
arrives without diminution of pressure in the chamber of the firing valves and
surrounds the valves J'. Here its pressure upon the flange J' tending to close the
valve is however more than counterbalanced by its pressure upon the flange or
piston J for this latter is larger in diameter than J* and presents a larger area for
the air to pross against. The pressure of the air in the chamber surrounding the
valve therefore tends to lift the valve from the seat J and allow the air to pass into
the barrel. This tendency to lift is however more than neutralized by the pressure
of the air above the piston J in that part of the chamber marked for this pressure
acting upon the whole upper surface of the valve forces it down upon the seat Jo
with, in the case of a large valve, a very considerable pressure. It is however
evident that if the chamber was suddenly opened to the atmosphere the air therein
would escape and the pressure upon the piston J' in excess of that on J would raise
the valve and allow the air to rush into the barrel and propel the projectile. This
accomplished, if the opening by which j¹ was relieved of the pressure was closed, and
the pressure allowed to accumulate in that space the valve J would be closed and the
passage of the air into the barrel stopped.
The operation of opening and closing the valve J is therefore reduced to that of
discharging the pressure in chamber and allowing it to accumulate therein.
To accomplish this that is to alternately release and apply the pressure of the
compressed air to the piston J what may be called an auxiliary valve is employed, a
suitable form of this valve being shown in position at K in figs. 22 and 23. Its
construction is clearly shown in figures 24 to 28.
It consists primarily of a casting K of bronze or other suitable metal having a
cylinder K and a chamber K2 side by side each adapted to allow the play of a
suitable piston which in each case is of two sizes. The cylinder K¹ is closed at the
back end by a cover K³ one of the fastening bolts for which is shown in figure 24.
The valve in this cylinder consists of a double piston the smaller or front end of
which is marked Kand the larger or rear end is marked K' in figs. 24 and 25.
Between these pistons the valve is turned down to a smaller diameter leaving an
B

page_text: annular space in the cylinder surrounding that part of the piston which space forms
a free communication between the two belts K K' each of which is continued through
the lower side of the casting and swelled into a round opening k k ending in a
common flange K8 by which the valve casting is bolted to the top of the double chest L
shown in figs. 21, 22 and 23. It is to be noted that the belt K and its nozzle 4* is
over that chamber in the chest. L which is marked [Fig. 21 from which pipes L³
are led on either side to that part of the firing valve chambers marked that is
above the pistons J while that belt in the auxiliary valve narked K with its nozzle k
is over that chamber in the chest L that is marked L2 from which pipes L are led
on either side to the firing valve chambers J in that part surrounding the valve.J
where the pressure from the reservoirs is always maintained when the gun is in use.
As shown in fig. 24 and also in fig. 26 in the latter of which the auxiliary valve
chamber K is shown without its pistons and the course of the air pressure is shown
by arrows, it is evident that the reservoir pressure is free to pass from J figs. 21
and 22 along the pipes L into the chest L and rise into the belt K7 figs. 26 and 24
and thence as indicated by the arrow into belt K and down through nozzle ke into
the chamber L' of the chest L and along the pipes L' on either side to the firing
valve chamber and it is in this way that the pressure of the air is maintained upon
the face of the piston Je of each firing valve and the valve itself kept closed as is
shown in section in fig. 21.
Examination of fig. 24 will show that when the valve K K is in its closed
position upon the seat K10 it forms no obstruction to the free passage of the air as
above described. But this air pressure between the pistons K K' tends to throw the
valve back toward the cover K³ and thus open the valve by reason of the larger
area of K over K its throw in that direction being limited by the stop ³ formed upon
the cover acting upon the soft buffer K to receive which the valve is hollowed out as
shown. But as the reservoir pressure is maintained in the space k between the
cover K³ and the valve the pressure acting on the whole area of K keeps the valve
tightly upon its seat K and no movement can take place under these circumstances.
But it is evident that if the pressure in the space was reduced the valve would be
forced back on the buffer into the piston shown in fig. 25. In that case the piston K*
which fits accurately that part of the cylinder in which it is shown in fig. 24 will
occupy the space between the two belts K K in which it fits as well, and in this
new position as represented in fig. 25 it forms a complete barrier against the passage
of air under pressure from K to K. But the valve in making this movement
moves from its seat K10 and allows communication between the open air and the
belt K and so through the pipe L with the space above the firing valve J³
figure 21. The pressure on this valve being thus released the air escapes as shown
by the arrows figure 25 and the valve is instantly opened and the air from the
firing reservoirs admitted to the barrel of the gun. It is evident also that to close
the firing valve it is only necessary to restore the pressure in the space k to the back
of the auxiliary valve K³ when it will be driven down upon its seat K10 restoring the
position shown in fig. 24 where communication is cut off between and the open
air, and is again opened between j¹ and the reservoir pressure which instantly closes
the firing valve by moving it into the position shown in fig. 21.
So far it is apparent that just as the firing valves are opened and closed by alternately
releasing and applying the reservoir pressure in the spaces so the auxiliary valve is
operated by releasing and applying the same pressure in the space k the
communication between all three valves causing their motions to be alike and
simultaneous.
It now remains to show how the pressure in the space is alternately discharged
and applied to operate the auxiliary valve.
By a port marked k¹ shown in figs. 24, 25 and 28 communication is effected
between the space k and the chamber K of the auxiliary valve casting..
This chamber is open at both ends. At the front end it opens to the atmosphere
as shown in fig. 25 and at the back end it communicates with the air pressure
existing in the reservoirs through a passage 2 and a regulating cock N figs. 24, 25

page_text: 26 and 27 and which is shown also in fig. 23 as mounted on a flanged connection
which forms part of the chamber L2 which, as before described, has unbroken
communication with the air in the firing reservoirs. The use of this regulating
cock will be presently shown, at present it is to be considered as more or less open
as shown in figs. 24 and 25.
In this chamber K2 is fitted the primary valve M, called primary because it is the
first one operated in the act of firing the gun. This valve M has a short portion M¹
which is larger than the rest of the valve the diameter of which portion accurately
fits a short part K" of the cylinder and its front face closes down upon a seat K" of
preferably fibrous material which is itself held in place by a gland K". The rest of
the valve is turned to a smaller diameter M and accurately fits a portion of the
casting K at the rear end. The valve M is hollow as shown and its interior
communicates through the passage with the regulating cock N through which the
air pressure acts continuously to keep it closed upon its seat K". A number of small
holes m are drilled from the outside of the valve into the hollow in such a position
that when the valve is closed upon its seat as shown in fig. 24 they open into the
port but when the valve is open as shown in fig. 25 the holes m are back in that
portion of the casting marked M2 which covers them and communication between
the regulating cock and the port k¹ is thus cut off.
This valve M is sufficiently small, notwithstanding the immense pressure to which
its rear end is subjected to keep it closed, to be opened by the hand of the gunner
under suitable conditions of leverage such as are provided and shown in fig. 2 where
P is the lever and P¹ the rod leading to the valve, the throw of the lever being
limited in either direction by a quadrant P. The lever P is shown in fig. 2 in that
position which corresponds to the position of the primary valve M that exists in
fig. 24. But if the lever is pushed to the other extreme of its throw, the rod P1 by
means of a catch P³ acting against the end of the valve stem at M³ fig. 24, forces
the valve M inwards into the position shown in fig. 25 the effect of this being to first
close the holes m, thus cutting off the pressure from the port k¹, and then as the valve
face moves out of that part of the chamber K2 in which it fits at K to make
communication between the space k at the back of the auxiliary valve and the open
air as shown by the arrows in fig. 25. The pressure on the back of the auxiliary
valve K' being thus released it flies back against the buffer, and in consequence as
already described the firing valves are opened.
But although the gunner can push the valve M open he cannot hold it open, for the
movement of the auxiliary valve backward releases the primary valve from his control,
for the spring catch P' being at its longer end forked around the stem of the auxiliary
valve is pulled back by the adjustable collar P' in its movement as shown in fig. 25
and in so doing the shorter arm of the catch is freed from the stem of the primary
valve as shown at M' fig. 25 and the primary valve M closes instantly under the
pressure upon its rear ond from the regulating cock N. The effect of this closing is
to at once allow the air pressure from the reservoirs to flow through the holes m into
the space behind the auxiliary valve, and so great is the tension of the air under
the enormous pressure existing in the reservoirs that the opening and closing of the
primary, the auxiliary and the two firing valves would be practically simultaneous,
were means not provided for allowing the auxiliary valve, and with it the firing
valves, to remain open a sufficient length of time to permit the air pressure to act
efficiently on the projectile.
But the time of
As already described the primary valve M is closed almost as soon as it is
opened, by the instantaneous opening of the auxiliary valve.
the closing of the auxiliary valve may be controlled and determined by the
regulating cock N. This is provided with a closely fitting plug N having a
stem N' on the end of which is a sufficiently large handle N to enable the plug
to be turned. The plug is hollow and on one side bas an opening n through which
the air can enter into the passage to the end of the primary valve with its holes m.
It is evident from the inspection of the drawings that the plug may be turned by

page_text: this handle into any position, so that either the opening n may correspond with the
passage as in fig. 24 or that passage be covered by the solid part of the plug and
thus entirely closed, or it may occupy any intermediate position such as is shown in
fig. 25. If the passage is left entirely open as shown in fig. 24, the firing valves
will scarcely open at all, for the space will be filled with air pressure almost as
soon as it is emptied, the interval between release and re-supply being too short to be
measured. If, on the other hand the plug N' be so turned as to entirely close the
end of the passage the auxiliary valve would never have the pressure restored to
its rear face, consequently it would remain open and the firing valves would remain
open and the entire contents of the firing reservoirs would be exhausted into the open
air through the muzzle of the gun.
But the plug may be so turned as to leave uncovered only a small part of the
passage and this uncovered portion may be so contracted as to allow the pressure to
return to the space k in an appreciable period of time and according to the size of the
opening given to the air pressure to flow in so will the time vary that is occupied by
the auxiliary valve in returning to its seat. To accomplish this with the greatest
delicacy the rear end of the passage is so shaped that a considerable movement of
the plug makes but a small variation in the amount of opening, particularly at that
part of its movement when the opening is nearly closed. The shape of the opening
of the passage k² is shown in dotted lines in fig. 27 and in full lines in fig. 27" which
is a sectional elevation of a portion of the regulating cock and in which figures it will
be seen that one side of the hole is brought down to a fine point at the closing side.
The amount of opening allowed is shown by a dial M' which moves with the handle N³,
the numbers of which dial may be recorded as allowing the requisite amount of
air to pass into the barrel to produce certain ranges of the projectile with given
elevations of the gun.
For the purpose of elevating the muzzle of the gun to any desired angle a hydraulic
ram is provided as shown in figs. 1, 2 and 4. It consists of a cylinder 0 attached
at one end to a heavy casting.0 that reaches from one side of the gun carriage to
the other terminating at each end in trunnions, heavy ribs 02 connect the cylinder
with the trunnion bar so as to add strength and stiffness to the structure. The trunnions
rest in trunnion blocks O³ 0* fastened to the sides of the carriage. In the cylinder O
works a ram O figs. 1 and 4 having a forked end 0 upon which rest the truss hars Gr
suitable blocks 07 see fig. 2 being fastened to the truss bars to receive the ends of the
fork. The hydraulic pressure is applied to the ram through a hole which extends from
one of the trunnions to the lower end of the cylinder a pipe o being attached to the
trunnion to convey the motive fluid thereto.
Although the gun is centred as before described upon the pintle A yet it is
intended that its weight should be mainly carried by wheels or rollers running upon
a smooth track. These are placed immediately under the frame of the carriage and
are marked Qin fig. 2, one only being shown in fig. 1 at the rear end of the carriage,
those at the front end being omitted, so as not to interfere with the view of the
rotating or training mechanism. These wheels run upon a circular track Q' secured
to a suitable foundation concentric with the pintle at such a height as to take the
larger part of if not the entire weight of the apparatus.
For the purpose of training the gun around the pintle a hydraulic motor is attached
to the carriage. It is shown in plan at R fig. 4, and less completely in fig. 2, being
secured to a casting R' reaching from side to side of the carriage. The shaft of the
motor passes down through a bearing R2 fig. 1 and carries a toothed pinion R³ which
engages an internal gear R* fastened to or formed upon the track Q. The motor is
preferably multicylindrical, because such motors have no dead points and therefore do
not require fly wheels, the momentum of which might carry the gun in its rotation
beyond the point at which it might be desired to stop. Both the elevating ram and
the training motor are connected by pipes (not shown) to suitably constructed valve
chests or cocks which are placed at any convenient position on the carriage or
trunnion block such as is indicated at S S¹ in figs. 1 and 2 upon one of the trunnion

page_text: blocks, the valves themselves being shifted by levers S² S³ one of which controls the
elevating ram to elevate or lower the gun, the other controlling the motor for training
the gun by rotating it in either direction.
The motive fluid under pressure which actuates the ram and motor may be supplied
by a pump situated at any convenient place in reference to the gun, the pipe from
the
pump being carried to the nozzle A fig. 20 from which it rises as there shown
by the arrows to the top of the pintle. The nozzle A on the opposite side of the
pintic is used for the return passage of the fluid after it has passed through the ram
and motor. The manner in which these ducts in the pintle which are stationary are
connected to the valve chests or cocks S S¹ which revolve with the gun is shown in
fig. 20. A is the pintle, A³ being the nozzle into which a pipe a is led from the
reservoir in which the oil is maintained under suitable pressure by a pump, A being
the nozzle from which a pipe a conveys the liqnid back to the pump after being dis-
charged from the ram O or training motor R. The ducts for the conveyance of the
liquid are continued to the top of the pintle and end in screwed holes A7 and A³.
Into the hole A is screwed a pipe connected with a cup shaped casting T of bronze
or other suitable metal which has two seats t and u formed centrally therein, the
smaller and lower one t of which forms a direct continuation of the pipe leading
from A. The axial line of these seats is coincident with that of the pintle. Upon
the seat t is fitted a central pipe T' having an enlarged end shaped to correspond with
the seat t, the two being ground to an exact fit and making a tight joint. The pipe T¹
is held in place upon the seat by a screwed collar t¹ which is screwed into a recess
adapted for it above the soat t. As thus arranged the pipe T₁ can turn upon the seat,
and from its upper end a suitable fitting 2 with a pipe ts and a branch fitting t* is led
to the valve chests S, S¹ Figs. 1 and 2. The course of the oil under pressure from
the nozzle A³ to t t is shown by arrows marked 8.
a
Upon the upper seat u in the cup shaped casting T is fitted a pipe U of much
larger diameter than T and having large collar U on the lower end, the under
surface of which is shaped to fit into the seat u the two faces being ground to an
exact fit.
A screw gland U bears on the upper surface of the collar U¹ to hold the
pipe U in place. The upper end of the pipe U is formed into a stufting box for the
passage of the central pipe T by a bottom u¹ a follower u³ and a gland ³ an annular
space U being thus formed in the pipe U, the lower part being made tight by the
ground seats t u and the upper part by the stuffing box. Into this annular space the
discharged oil from the ram O and training motor R is led by pipes entering
the nozzle U³ in the pipe U and by a pipe T2 led from a nozzle in the side of the
casting T to the nozzle A in the pintle, whence it is discharged by the nozzle A*
through a suitable pipe to the pump. The course of the returning liquid is shown by
arrows marked s¹.
•
It is evident that the pipes 1 and U in this arrangement form part of the rotating
system of the gun, the points of connection of these with the stationary parts being
the ground seats t, u of each in the casting T. The contained oil affords ample and
permanent lubrication for the preservation of the seats.
It is important both for the safety of the gun and for its stability in the act of
firing that it should be relieved from all strains produced by unbalanced pressures,
and particularly those strains resulting from the recoil of any of its parts when a
large portion of its contained air is suddenly allowed to rush into the barrel to impel
the projectile.
So far the gun has been described as constructed with this object in view, the
pintle, the yoke and the trunnions being so made that their strains are self contained,
and the trunnion blocks, side pipes and firing valves are doubled, so that wherever
pressure or recoil acts upon the gun, or any of its parts to force it in one direction an
equal force of pressure or recoil acts simultaneously in an exactly opposite direction. The
initial recoil upon the breech of the gun in the act of firing cannot be so relieved and
this is taken up upon the trunnion blocks which are purposely made strong and of
the best shape for this purpose. The final recoil is received upon the farthest ends of
the firing reservoirs, and tends to break them from their connections. In order that

page_text: this recoil may not act upon the pintle to which they are connected, either to break
it or move it upon the foundation or shake the gun when it is fired the air-reservoirs
are so constructed and set, that as a whole their recoil is self contained. To this end
they should be placed symmetrically to the pintle in two or more sets, or they may be
placed radially to it, so that when the pressure is suddenly reduced the recoil will
always be in opposite directions. The simplest arrangement is shown in figs. 1 and 3
where there are two sets of firing reservoirs one on each side of the pintle. Each set
is shown in fig. 3 as containing an equal number of chambers W these being con-
nected to heavy branch pipes W' and these again by pipes W2 to the nozzles A¹ of
the pintle. In order that no strain may come upon either the branches W¹, the
pipes W or the flanges of the nozzles A, the ends of the branches of each set are
connected across by strong metal ties Ws firmly secured to each end of each branch.
A nozzle W is arranged to admit the air that is supplied by the air pumps to
the reservoirs.
Projectile carriage. A projectile for the gun is shown in figs. 1 and 2, V being the
projectile resting on a carriage VI constructed to hold the projectile at the proper
height and at the same angle at which the gun is placed for loading, though such an
angle is not necessary, and a level position may in many cases be preferable. The
carriage is so constructed that it may naturally and easily roll upon a track V2 con-
centric with the training movement of the gun so that the projectile may always be
carried to the breech of the gun wherever it is situated in its circle of rotation. Two
or more carriages may be used so as to keep a supply of projectiles ready for loading.
The projectile lies in a smooth trough in the carriage, and it is pushed easily and
quietly into the open breech of the gun by a rod V3 held by a saddle V* sliding upon
guides upon the carriage. The projecting ends of the saddle are attached to
chains one on each side of the carriage by which the saddle is drawn toward the
gun pushing the projectile before it, the chains passing over sprocket or pitch wheels
which are turned by means of toothed wheels and pinions as shown in figs. 1 and 2
these pinions being themselves turned by cranks v²
in the hands of the gunners.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. The application of the pressure of elastic fluids in such a manner that it is
balanced in reference to its action on all the working parts of a pneumatic gun
substantially by means such as are herein described.
2. In or in connection with a pneumatic gun the opposite arrangement of the
reservoirs about a hollow support or pintle for the purpose of balancing strains or
shock substantially as described and illustrated in figure 3 of the accompanying
drawings.
3. In a pneumatic gun a hollow central support or pintle such as A in which
the air pressure is balanced substantially as described and illustrated in the accom-
panying drawings.
4. In a pneumatic gun a pintle such as A closed at top and bottom receiving the
air from opposite sides and distributing it around its circumference substantially as
described and illustrated in the accompanying drawings.
5. In a pneumatic gun the combination in the same pintle of the passage or
passages by which is conveyed the compressed air for firing the gun and the passage
or passages by which is conveyed the liquid pressure for elevating and training the
gun substantially as described and illustrated in the accompanying drawings.
6. In a pneumatic gun the combination with a pintle such as A delivering the
compressed air radially around its circumference of a yoke such as B adapted to
receive the compressed air from the said pintle and deliver it in opposite directions
for the purpose of balancing the strains substantially as described and illustrated in
the accompanying drawings.
7. In a pneumatic gun the combination with a pintle such as A of a yoke such as B
having a belt or annular recess B* and opposing passages B substantially as and for

page_text: the purpose described and illustrated in the accompanying drawings.
8. In a pneumatic gun a trunnion such as F closed at each end and receiving the
compressed air radially towards its axis for the purpose of avoiding unbalanced
pressure substantially as described and illustrated in the accompanying drawings.
9. In a pneumatic gun the combination with a trunnion such as F adapted to
receive the compressed air around its periphery radially towards its axis of a trunnion
block such as Chaving a chambered head for the purpose of supplying the air to the
trunnion without unbalanced pressure substantially as described and illustrated in the
accompanying drawings.
10. The combination with a pneumatic gun of two or more firing valves balancing
the admission of air into the gun substantially as herein described and illustrated in
the accompanying drawings.
11. In a pneumatic gun the combination with the firing valve of a stop adjustable
from the outside of the casing substantially as described and illustrated in figures 21
and 22 of the accompanying drawings.
12. In a pneumatic gun the method of preventing leakage at the working joints
by the application of liquid pressure in excess of the air pressure substantially as
described.
13. In a packing for the working joints of a pneumatic gun the combination with
a pair of annular recesses or spaces of a double ring or distance piece such as D³ D*
substantially as and for the purpose described and illustrated in figure 13 of the
accompanying drawings.
14. In a packing for the working joints of pneumatic guns the combination with
two packing rings such as D D² of a separating ring such as D₁ provided with
openings d substantially as and for the purpose described and illustrated in figure 13
of the accompanying drawings.
15. The arrangement and combination of parts forming the complete packing for
the working joints of pneumatic guns substantially as described and illustrated in
figure 13 of the accompanying drawings.
16. In a pneumatic gun the combination with a joint packing such as described of
a differential cylinder such as E whereof that portion having the larger area is in
communication with the air pressure and that portion having the smaller area is in
communication with the said packing substantially as described and illustrated in
figures 13 and 15 of the accompanying drawings.
17. In a pneumatic gun the combination with the auxiliary valve K³ and primary
valve M of a trigger such as P3 substantially as and for the purpose described and
illustrated in figures 24 and 25 of the accompanying drawings.
18. In a primary valve for a pneumatic gun the combination with a hollow valve
such as M having apertures m and a head M¹ of its chambers and seatings such
as K K M² the whole constructed and operating substantially as described and
illustrated in figures 24 and 25 of the accompanying drawings.
19. In a pneumatic gun the combination with the primary valve of a cock such
as N N¹ operating in conjunction with a tapered opening such as k the whole con-
structed and operating substantially as described and illustrated in figures 24, 25 26
27 and 27 of the accompanying drawings.
20. The arrangement and combination of parts constituting the complete pneumatic
gun substantially as described and illustrated in the accompanying drawings.
1
T
1000
W. P. THOMPSON & BOULT,
Agents for the Applicant.