Improvements in Automatic Guns.
Year: 1896

page_text: Improvements in Automatic Guns.
I, HUGH WILLIAM GABBETT-FAIRFAX, of 107 Lambeth Palace Road, London,
S.E., Civil Engineer, do hereby declare the nature of this invention to be
follows:-
This invention has for its object to so construct automatic guns, that the breech-
mechanism, instead of being operated by the energy of recoil or by the pressure
of the gases of discharge, can be operated by means of compressed gas or air or
liquefied gas contained in a detachable holder which is capable of being removed
when spent and replaced by a charged one. The said compressed or liquefied gas
may be also utilized for cooling the gun-barrel so that, in the case of machine
guns, the ordinary water-jacket may be dispensed with.
According to my invention I prefer to employ compressed or liquefied carbonic
acid gas contained in steel cylinders provided with suitable valve controlled out-
lets near one of their ends and these cylinders are in the case of a small-arm
adapted to enter a suitable recess or cavity formed for their reception in the stock.
When one of the said cylinders is inserted in place within this recess or cavity
its valve-end comes into engagement with a socket which is formed in a chamber
arranged at the inner end of the aforesaid recess or cavity. The act of inserting
the said gas-cylinder into place causes the valve of the cylinder to open and put
the contents of said cylinder into connection with the aforesaid chamber. This
chamber is situated in contiguity to, or may form part of a working cylinder con-
taining a piston which is appropriately connected by rods and levers to some suit-
able moving part of the breech mechanism, say the hammer in the case of a
small-arm, or the reciprocating breech-lock in the case of a machine gun.
aforesaid chamber to which the contents of the gas cylinder have access, as above
stated, serves as a valve chamber in which the valve or valves work for regulating
the inlet and outlet of the gas to and from the working cylinder. The said valve
or valves are so arranged that the cocking of the hammer or the operation of some
other appropriate part or device, will cause them to assume the proper position for
enabling the gas to enter the working cylinder, so that when the trigger is pulled
and the weapon discharged the piston will be then operated to work the breech
mechanism and will continue working as long as the trigger is pulled. Instead of
making the cylinder double acting, I may employ a suitably arranged spring
which becomes stretched or compressed as the piston moves in one direction, and
reacts to drive said piston in the opposite direction.
The
In some cases it may be found preferable to operate the aforesaid valve or valves
by a movement of the barrel which is arranged to recoil for such purpose.
The exhaust gas passing from the aforesaid working cylinder is conducted by
suitable conduits to the barrel, into which or around which it is allowed to escape
for the purpose of keeping the said barrel cool.
Dated this 20th dove of Suntambian 1800
HASELTINE LAKE & Co.
45 Southampton Buildings, London, W.C. Agents for the Applicant.

page_text: Improvements in Automatic Guns."
I, HUGH WILLIAM GABBETT-FAIRFAX, of 107 Lambeth Palace Road, London,
S.E., Civil Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:
This invention has for its object to so construct automatic guns, that the breech-
mechanism instead of being operated by the energy of recoil or by the pressure
of the gases of discharge can be operated by means of an independent source of
compressed gas or air or liquefied gas, that is to say compressed air or gas con-
tained in a vessel which is preferably adapted to be removed when spent and
replaced by a charged one. The said compressed or liquefied gas may be also
utilised for cooling the gun-barrel so that, in the case of machine guns, the
ordinary water-jacket may be dispensed with.
According to my invention I prefer to employ compressed or liquified carbonic
acid gas contained in steel cylinders provided with suitable valve controlled out-
lets near one of their ends and these cylinders are, in the case of a small-arm,
adapted to enter a suitable recess or cavity formed for their reception in the stock.
When one of the said cylinders is inserted in place within this recess or cavity
its valve-end comes into engagement with socket which is in communication
with a chamber arranged near the inner end of the aforesaid recess or cavity.
The act of inserting the said gas-cylinder into its place causes the valve of the
cylinder to open and put the contents of said cylinder into communication with the
aforesaid chamber. This chamber is situated in contiguity to, or may form part
of the working cylinder containing a piston which is appropriately connected by
rods and levers to some suitable moving part of the breech mechanism, preferably
the reciprocating breech-block. The aforesaid chamber to which the contents of
the gas cylinder have access as above stated, is provided with a valve or valves for
regulating the passage of the gas to the working cylinder. The said valve or
valves should be so arranged that the pulling of the trigger to fire the gun will
cause them to assume the proper position for enabling the gas to enter the work-
ing cylinder, so that when the weapon is discharged the piston will then unlock
the breech block, open the breech and otherwise operate the breech mechanism to
prepare the weapon for the next discharge. I prefer to employ a suitably arranged
spring which is compressed as the breech-block is drawn backward to open the
breech and which reacts to move forward the breech block and return the said
piston to its original position.
The exhaust gas passing from the aforesaid working cylinder is conducted by
suitable conduits to the barrel, into which or around whch it is allowed to escape
for the purpose of keeping the said barrel cool.
In some cases it may be found preferable to operate the aforesaid valve or valves
by a movement of the barrel which is arranged to slightly recoil for such purpose,
and under these circumstances the firing of the weapon would take place auto-
matically so long as the trigger is held back.
In order that my said invention may be clearly understood and readily carried
into effect I will proceed to describe the same more fully with reference to the
accompanying drawings, in which :-
Figure 1 is a longitudinal section of a rifle constructed in accordance with my
invention, the parts thereof being represented in the position they occupy at the
instant when the trigger has been pulled to fire the weapon.
Figure 2 is a similar view with the parts in the position they occupy when the
breech-block has been fully withdrawn,

page_text: Figure 3 is a sectional plan shewing the breech-block, the working cylinder
and the case containing the spring for returning the breech-block to its firing
position.
Figure 4 is a cross section on the line 1.1 of Figure 1.
Figure 5 is a detail section showing the valve with which the gas cylinder is
provided.
Figure 6 similar view with the said valve in its closed position.
Figure 7 is a cross section of the said valve on the line 2. 2 of Figure 5.
A is the detachable vessel or cylinder containing the compressed or liquefied
gas. B is the socket in the stock of the rifle, into which the end of the said gas
cylinder fits. C is the chamber communicating with the said socket. D) is the
working cylinder into which the gas enters from the said chamber C to actuate
the piston E. F is the barrel. G is the breech-block. H is the extractor; I the
hammer; the main spring; J the firing pin; K the trigger; L the sear and M
the magazine.
The breech block is provided with a rotary locking head G having segmental
projections thereon to engage with corresponding internal recesses in the barrel
to lock the block thereto, as explained in the specification of my prior patent
No. 18686 of 1895. This head is mounted on a spindle Ga which is provided with
a spring controlled radial arm g that is adapted to work in a groove N shown in
dotted lines in Figures 1 and 2. This groove is formed in the casing N of the
weapon and is for the most part horizontal, but at its front end, or that end nearest
the barrel, it is formed with a downwardly curved portion N for the said radial
arm to enter when the rotary or angular movement of the locking head G₁ takes
place. Pivoted to the side of the breech block at g' is a bell crank lever the longer
limb g of which is formed with an elongated hole g to engage with the aforesaid
radial arm g-
The shorter limb g is connected by a ping to a link g which is
pivoted at g' to the piston rod E. By these means, when the piston E is shifted
in the direction of the arrow in Figure 1 by the pressure of the compressed gas
entering the working cylinder D, the longer limb of the said bell crank lever is
caused to turn upwardly whereby the unlocking of the rotary locking head from
the barrel is effected; then by the continued movement of the. said piston the
breech block is drawn backward into the position represented in Figure 2.
D is a pipe passing from the exhaust port 12 of the working cylinder D to a
point in proximity to the breech of the gun. This pipe serves to convey the cool
gases of exhaust from the said working cylinder to the interior of the barrel, into
which such gases pass and thereby cool the barrel. This arrangement enables me
in many cases to dispense with a water-jacket for keeping the barrel cool.
C Care valves situated at opposite ends of the gas chamber C, these valves
being so arranged that when one is opened the other is closed. The said valves are
provided with arms c c which are connected to a rod c whose free end is coupled
to an arm forming part of the trigger K, so that when the trigger is pulled the
valve C is caused to close the passage leading from the gas cylinder A to the
chamber C, and the valve C is caused to open the passage leading from the said
chamber C to the conduit D³ through which the compressed gas reaches the front
end of the working cylinder and thereby operates the piston E.
In order to avoid the liability of the breech-block's being actuated to open the
breech too soon, I provide for the existence of a small amount of lost motion
between the trigger and the rod c, whereby the first portion of the movement of
the trigger acts only to trip the sear L and release the hammer to fire the gun, a
further motion of the said trigger being required to operate the valves C¹ C³. For
this purpose, the end of the aforesaid rod c where it is connected to the arm k of
the trigger is provided with a slot through which the pin connecting the said
rod to the arm k extends. I may however employ other means for the purpose.
C is a spring controlled valve which acts to reduce the pressure of the com-
pressed gas entering the chamber C so that the working pressure is kept approx.
imately constant.

page_text: A is the valve with which the gas cylinder A is provided, such valve being
furnished with a prolongation a contained within a nozzle A3 on the gas cylinder.
This valve is normally held on its seat A3 by the pressure of the gas within the
gas cylinder A and it is formed with passages a¹ a through which the gas
escapes into passages a in the nozzle A2 when said valve is opened: The opening
of the valve is effected by its being forced inwardly in pressing against the nipple b
within the socket B, when the gas cylinder is inserted into place within the stock
of the rifle.
The stem of the aforesaid valve A is embraced by a collar as having circum-
ferential lugs to engage with slots in a recess a formed for the reception of said
collar in the nozzle A³. These lugs and slots permit the collar to slide on the valve
spindle without turning thereon. The said collar is also formed with lateral
holes a which when the valve A¹ is forced inward as shown in Figure 5 correspond
with the passages a and thereby place such passages in communication with the
passage a³.
When the said gas cylinder is detached from the fire arm the said
collar a is pressed outwardly by a spring as for a sufficient distance to cause the
passages and a to be disconnected as shown in Figure 6, thus ensuring that
no escape of the compressed gas from the cylinder A shall take place past the
valve A¹.
bbare passages in the socket B by which the gas is conducted to the reducing
valve C³. The said gas cylinder is screw threaded at A to engage with corre-
sponding screw threads in the socket B, a rectangular projection A5 being pro-
vided on the opposite end of the gas cylinder to enable a spanner or similar tool
to be employed for screwing the said gas cylinder firmly in place. The heel
plate O is pivotally connected at o to the stock of the rifle so that by removing the
screw o¹ the said heel plate can be opened to uncover the cavity which is formed in
the stock for the reception of the gas cylinder.
The breech block is furnished with an arm G³ carrying a disc or cap G4 which
slides in the case P against the resistance of a spring P¹ by which the breech
block is returned to its firing position after each discharge of the gun..
The working of the gun is as follows:-
When the trigger is pulled to fire the gun, it acts as already stated, first to
release the trigger and then to shift the valves C C into a position to shut off the
gas chamber from the cylinder A and open it to the working cylinder D. The
compressed gas within chamber C then passes into the working cylinder through
the pipe 13, and by acting on the piston E unlocks the breech block and withdraws
it into its rearmost position as explained above, thereby cocking the hammer and
extracting and ejecting the empty cartridge case. As the breach block retires,
the uppermost cartridge in the magazine assumes the position represented in
Figure 2 by the action of a magazine spring, as is well understood in magazine
rifles, the base of the said cartridge projecting a sufficient distance in the path of
the breech block to ensure that it shall be pushed forward by the breech block
when it advances. The piston E in moving backward to its full extent uncovers
the exhaust port 12 and permits the exhaust gas to flow through the pipe D' and
exert its cooling effect on the barrel in the manner already stated. During the
advance of the breech block, it carries the cartridge forward and pushes the nose
of its projectile against the incline Qwhereby such cartridge is inserted into the
cartridge chamber of the barrel simultaneously with the closing of the breech.
As the breech block completes its closing movement the radial arm g descends in
the portion N of the slot N¹ under the action of a spring, thus locking the head G¹
to the barrel. Meanwhile the release of the trigger has permitted the scar-spring
to return it to its normal position, whereby the valves C C have been caused to
assume the position represented in Figure 1 and a fresh charge of compressed gas
has been permitted to enter the chamber C ready for again actuating the piston
at the next discharge of the weapon.
I prefer to provide the pin with a knob or handle g* by which the unlocking

page_text: and movement of the breech block to operate the breech mechanism, can be effected
by hand when desired.
The pressure of the gas within the gas cylinder A is sufficient to enable the
breech mechanism to be operated a great number of times, say three thousand, and
in some cases it may be found unnecessary to provide for the removel of such
cylinder by the soldier. However I prefer to make the said cylinder detachable
as stated above in order that it may when spent be readily replaced by a charged
one.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I would state that I am
aware that attempts have previously been made to operate the breech mechanism
of a gun by fluid pressure obtained by compressing air in a working cylinder by
the recoil of the gun or of part of the gun; and I am also aware that guns have
been constructed in which compressed air or gas has been employed in place of
powder gases for projecting the bullets from the gun; my invention does not how-
ever relate to guns of either of these classes nor do I wish to claim a gun intended
to operate in such manner, but what I do claim is:-
1. A breech loading fire arm in which the breech mechanism is actuated succes-
sively by the pressure derived from an independent source of compressed air or
gas for the purpose specified.
2. The combination with a breech-loading fire arm of a vessel containing con-
pressed gas or air and arranged in combination with the working cylinder for
automatically actuating the breech mechanism substantially as described.
3. In a breech loading fire arm provided with a vessel of compressed gas o air
for operating the breech mechanism, means whereby the said gas or air is utilred
for cooling the barrel so that a water jacket for the said barrel can be dispensed
with.
4. A breech loading fire arm provided with a working cylinder whose piston is
adapted to be actuated by compressed air or gas contained in a suitable vessel such
piston being so connected to the breech-block by appropriate mechanism that it
will act first to unlock the block and then to withdraw it to open the breech sub-
stantially as described.
5. The combination with the aforesaid working cylinder of valves which are
connected to the trigger or other moving part of the mechanism in such a manner
that they will be operated subsequently to the firing of the gun, for the purpose
specified.
6. A compressed gas or air vessel having a valve which is adapted to be opened
by the act of inserting said vessel into place within the gun substantially as
described.
7. The combination with the aforesaid compressed gas or air vessel and the
working cylinder of an intermediate chamber provided with valves for the purposes
specified.
8. The improved breech loading fire arm in which the breech mechanism is
constructed and adapted to be operated, substantially as described with reference
to the accompanying drawings.
1.100.1
TI 100-
HASELTINE LAKE & Co.
45, Southampton Buildings, London, W.C. Agents for the Applicant.