Improvements relating to Guns Worked by Compressed or Liquefied Gas.
Year: 1891

page_text: Date of Application, 9th Mar., 1891
Complete Specification Left, 9th Jan., 1892-Accepted, 13th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements relating to Guns Worked by Compressed or
Liquefied Gas.
We, JOHN STEWART WALLACE, of Cliftonville Avenue, Belfast, Ireland,
Timber Merchant, and BENJAMIN THOMAS LINDSAY THOMSON, of 4 Altenburg
Gardens, Clapham Common, in the County of Surrey, Engineer, do hereby declare
the nature of this invention to be as follows:-
Our invention relates to guns worked by compressed or liquefied gas, and more
particularly to guns of the kind or class now commonly known as Giffard guns, in
which the expansive force of liquefied gas is used for discharging the projectiles.
One feature of our said invention is the construction of the breech-mechanism in
such a manner that the hammer or striker instead of being moved forward as in an
ordinary gun, will be moved backward when released by the pulling of the trigger,
and will strike the stem of a valve which controls the discharge of the gas from a
reservoir arranged within the stock or butt of the gun or in any other convenient
manner. Or the said hammer is adapted to strike a rod or other suitable device
connected with the said valve for the purpose of opening the same and permitting
the egress of a charge of gas.
Another feature of our said invention is the construction of double barrelled
sporting guns and rifles on the principle of the Giffard gun. I find it advantageous
for this purpose to provide simple and efficient means whereby the propelling force
for the discharge of projectiles from both barrels of a double-barrelled gun may
be obtained from a single reservoir of compressed gas having but one valve or vent
for the passage of the gas therefrom.
Our said invention moreover comprises the construction and arrangement of the
hammer and trigger in such a manner that in the backward movement of the
trigger, the hammer is first raised or cocked and then released and allowed to
operate to effect the discharge of the required quantity of gas.
Our said invention also comprises improved means for feeding or transferring the
bullets or shots from a magazine to the barrel of the gun and our said invention
further comprises other improvements hereinafter mentioned.
In making a double-barrelled gun according to our said invention we prefer to
arrange a reservoir containing the compressed or liquefied gas in a recess or cavity
formed for the purpose in the stock of the gun in rear of the barrels, the said
reservoir being so situated that the end thereof containing the valve is adjacent to
the breech end of the barrels. We provide suitable gastight chambers extending
from the said reservoir to each of the barrels ; and we so arrange hammers or
strikers that in their cocked position, they press against and serve to close the
breech end of the barrels, a ring or washer of india rubber or other suitable
material being provided between each hammer and the corresponding barrel to
effectually prevent the entrance of the gas into the said barrel while the hammer
is cocked.
For communicating the blow or impact of the hammers to the valve in the
reservoir, we provide a striking pin or rod, preferably L-shaped in transverse
section or otherwise so formed as to permit the flow of the gas through the passage
in which the said rod is fitted. This striking pin or rod is so arranged that, when
either of the hammers is released by the pulling of the corresponding trigger, the
said striking pin or rod will be thereby driven inward against the force of a suitable
spring, and will open the valve and thus permit the escape of a charge of the
compressed or liquefied gas from the reservoir. The gas thus liberated, enters the
barrel the hammer of which has just been released, and discharges the said barrel,

page_text: The other barrel, however, remains inoperative, being closed by the cocked hammer,
which is pressed more firmly against the breech end of the said barrel by the
pressure of the liberated gas. We can, if desired, use two of the said striking pins
or rods one for each hammer; and we can if desired use a reservoir in combination
with each barrel.
The barrels of the gun are of ordinary construction and may be hinged to the
stock in the usual or any other convenient manner.
When the gun is opened, the hammers or strikers are, by any convenient means,
cocked or brought into a position ready for striking. The charge of shot, made up
in any convenient manner, is inserted in the barrel when the gun is opened. The
gun now has both strikers ready for firing, and in the position covering the openings
of their respective barrels. Should either trigger be pulled, the hammer or striker
in connection with that trigger will fall and hit the striking pin, and the gas will
escape. The
pressure of gas, however, against the striker that remains in position
against the corresponding barrel will, as above stated, effectually close this barrel
so that the whole of the gas will be diverted to the barrel whose striker has fallen.
We sometimes construct a gun wherein the trigger
so combined with the hammer
or striker that, by the pulling of the said trigger the hammer or striker will be
first cocked and then released. For this purpose, we find it advantageous to provide
a hooked link which is coupled to the trigger and is acted upon by a spring whereby
it is held in engagement with a shoulder or projection on the hammer. When the
trigger is pulled this hooked link turns the hammer through a certain angle about
its pivot, and the said link is then automatically disengaged from the said hammer.
The hammer being thus released, flies back under the action of its spring and
strikes the valve of the reservoir thereby operating the same and liberating a
portion of the gas contained therein which then passes through a suitable channel
or passage to the barrel of the gun.
After the hammer has thus operated and the trigger is allowed to move forward,
the hooked end again engages with the hammer so that it is ready to again operate
the same.
In applying our invention to a magazine gun or rifle we find it advantageous to
provide a revolving cylinder or disc having recesses or chambers formed therein to
receive the projectiles. This cylinder is so situated that the recesses in passing the
opening of the magazine receive the projectiles therefrom and then convey them in
the revolution of the said cylinder into line with the barrel of the gun through
which they are projected by the gas liberated by the action of the hammer or
striker. We also provide suitable mechanism which is worked by the movements
of the hammer to impart intermittent rotation to the said cylinder and thus bring
the recesses or chambers therein consecutively in line with the barrel of the gun.
The magazine which we prefer to employ consists of a slotted tube arranged
beneath the barrel and containing a spiral spring situated in the forward extremity
thereof, which presses upon or against a sliding piece or follower and moves or tends
to move the said follower towards the rear end of the magazine. A projection or
thumb piece connected to the follower projects through the slot in the magazine
and enables the follower to be moved to and fro therein by hand if necessary from
the exterior thereof. The magazine is charged from the rear end thereof and the
aforesaid sliding piece or follower is thereby moved towards the forward end of the
magazine so compressing the spiral spring contained therein and storing up energy
to effect the feeding of the projectiles from the said magazine into the recesses or
chambers in the aforesaid revolving cylinder.
Dated this 04 M1 1001
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements relating to Guns Worked by Compressed or
Liquefied Gas.
We, JOHN STEWART WALLACE, of Cliftonville Avenue, Belfast, Ireland,
Timber Merchant, and BENJAMIN THOMAS LINDSAY THOMSON, of Altenburg
Gardens, Clapham Common, in the County of Surrey, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
"
Our invention relates to guns worked by compressed or liquefied gas, and more
particularly to that kind or class now commonly known as "Giffard guns in which
the expansive force of liquefied gas is used for discharging the projectiles.
An important feature of our said invention is the construction of the breech
mechanism and arrangement of the same in combination with the reservoir in such
a manner that the hammer or striker instead of being moved forward as in ordinary
guns is moved backward when released by the pulling of the trigger.
Another feature of our invention is the application of the "Giffard" principle
to double barrelled sporting guns and rifles. In constructing a double barrelled
gun on this principle we find it convenient to so arrange that one reservoir supplies
the energy for both barrels. In some cases however we provide a separate reservoir
for each barrel.
According to another part of our invention we arrange that when the trigger is
operated it shall first cock the hammer and then release it.
Our said invention also comprises improved means for feeding or transferring the
bullets or shots from a magazine to the barrel and it also comprises other improve-
ments hereinafter described.
In the accompanying drawings;
Figure 1 is an elevation of the stock and breech portions of a single barrelled
gun constructed according to our invention some of the parts being removed.
Figure 2 is a transverse section on the line 2, 2, Figure 1.
Figure 3 is a side elevation of the cocking lever.
Figure 4 is a section on the line 4, 4, Figure 3.
Figure 5 is a sectional elevation, some of the parts being removed, and
Figure 6 is a plan, partly sectional, of the stock and breech portions of a double-
barrelled gun constructed according to our invention.
Figure 7 is a cross section of the valve rod taken on line 7, 7, Figure 5.
Figure 8 is a sectional elevation of the stock and breech portions of a self
cocking single barrelled gun, constructed according to our invention.
Figure 9 is an elevation partly sectional of our improved magazine and mechanism
for transferring the shots to the barrels, and
Figure 10 is a cross section on the line 10, 10, Figure 1.
A is the barrel of the gun, B is the breech shoe, C is the stock, and E is the
reservoir for the compressed or liquefied gas.
Referring now to Figures 1, 2, 3 and 4 the hammer D is pivoted at d and is
furnished with two notches or recesses formed respectively by a shoulder d¹ and
tail piece d³. a is the main spring secured to the breech frame by a screw a² and
which engages by means of its hooked end a' with the recess of the hammer
formed by the tail piece d.
g
e is a fever pivoted at 3 and formed with a hook adapted to engage with the
aforesaid shoulder d¹ in front of the hammer; f is a spring for maintaining the
said hook e in contact with the hammer D. The trigger which is pivoted at g³ is
formed with a tongue gl that can move between the tail part d' of the hammer and
the lever e. h is a rod mounted to slide in guides 6, 6º secured to the breech
frame. The said rod is provided to operate the valve in the fore part of the
reservoir E. The cocking device is as follows, k is a pin mounted in a bearing 6*

page_text: provided in the breech frame in line with the hammer pivot. The said pin is
formed with a lug which is adapted to engage with a projection on the
hammer D and has moreover a squared end on which is fitted a lever 1, the said
lever being secured thereon by a screw P. A spiral spring having one end secured
to the lever and the other to the bearing tends to keep the said lever in an
upright position and thereby to prevent the lug k¹ of the pin k from pressing against
the projection d³ of the hammer.
When the lever is pressel forward and downward the pink is partly rotated, its
lug engages with the projection and turns the hammer D on its pivot against
the force of the spring a, until the hooked lever e engages with the shoulder d.
On releasing the lever it turns back to its normal position under the influence of
the spring but the hammer is held in the cocked position by the hooked lever e.
When the trigger g is pulled the tongue g¹ operates to press the levere against the
spring and disengages the hammer. The latter is then forced backward by the
spring a and strikes the forward end of the valve rod h, thus opening the valve in
the reservoir and liberating a charge therefrom.
Figures 5 and 6 illustrate a double barrelled gun or rifle having a single
reservoir E for the compressed or liquefied gas.
is the valve rod moving in a channel in the solid end of the reservoir E. This
valve rod is cruciform in section as shown in Figure 7 so that the gas liberated
from the reservoir may escape through the grooves in the sides of the said rod into
the small space between the end of the valve rod and the hammers.
The barrels A communicate with the channel in the sides of the valve rod h by
means of oblique passages shown at B'. Referring now to mechanism connected
with one barrel, m is the hammer pivoted at m² and having a conical head m¹
which fits into the aforesaid passage B' in the shoe. The said hammer is moreover
furnished with a projection or shoulder m³ and has a fork m' at its lower end which
is rounded off on the rear side as shown at m³.
A
The trigger g is pivoted at 93 and at its forward end it is furnished with a
projection adapted to engage with the tail end n' of a lever n pivoted at n². The
forward end of the said lever is provided with a projecting part n³ which is adapted
to engage with the shoulder m³ of the hammer. The said lever has moreover a
rounded portion n* corresponding with the rounded part m³ of the hammer.
spring tends to keep the lever n in contact with the trigger g. o is a rod adapted
to slide in bearings in the shoe B. The said rod is attached to the forked end m⭑
of the hammer by a pin o¹. o* is a collar fixed on the rod o, and o³ is a spiral
spring bearing on the said collar at one end and at the other end pressing against
a slotted piece B' which is secured in the breech block or shoe. The end of of the
rod o projects beyond the front end of the breech block or shoe and is bevelled off
as shown. The barrels A are pivoted on the breech block or shoe at a³ and are so
arranged at the part A' as to engage with and press upon the forward ends o' of the
rods o when turned about the said pivot a³ to open the breech. It must be under-
stood that the parts mentioned above g, m, n, o are duplicated, one set for each
barrel of the gun and the said parts are so arranged that the conical hammer
heads m' both act on the same valve rod h. This construction is seen from the plan
view of Figure 6.
When the gun is opened in the ordinary manner by turning the barrels on the
pivot a the lower part of the barrels A1 act on the bevelled ends o* of the rods o
and force the said rods inwards thus compressing the springs o³. The hammers m
are thus partly rotated on their pivots and the heads m' thereof are caused to close
the holes B' in the breech block. The projections or shoulders m³ at the same time
slide up the rounded parts n' of the levers n until the said projections engage with
the parts n³. The hammer is thus cocked. The charge of shot or the like is now
inserted into the barrels and the gun closed again. Upon one of the triggers, the
left hand one for example being pulled, the rear end n' of the lever n is pressed
down against the spring n' and the part n³ moved out of engagement with the
shoulder m³, thus liberating the hammer and allowing the spring o³ to operate and

page_text: cause the hammer to strike the end of the valve-rod h, thus opening the valve and
setting free a portion of the compressed or liquefied gas from the reservoir. The
right hand barrel is during this time kept closed by its hammer head m' and the
pressure of the gas behind the hammer only helps to keep it closed the tighter,
hence all the energy of the liberated gas is utilized in the left hand barrel which
is thereby discharged. On now pulling the right hand trigger, the hammer head m¹
in the rear of the right hand barrel operates to liberate a portion of the gas in the
reservoir, this fills the channels in the valve rod and pressing on the head m³ of
the left hand barrel closes it. The gas is thus diverted into the right hand barrel
and discharges the same. A little play is preferably allowed at the hammer pivots
so that the closing of the discharged barrel may be accomplished by means of the
liberated gas pressing on the conical hammer head of the said barrel.
In Figure 8 we have shewn how one of our single barrelled guns may be made
self cocking, this is accomplished in the following manner, the leve e instead of
being pivoted to the breech frame is pivoted to the forward end of the trigger as
shown at e². When the trigger is pulled, the lever e is drawn downwards and thus
cocks the hammer by reason of the hooked part e¹ of the lever e engaging with the
projection d' of the hammer. After the hammer has been partially rotated, the
hooked part e becomes disengaged from and releases the hammer and the latter
flies back and strikes the valve rod h. When the trigger is released the trigger
spring presses it back to its original position thereby raising the lever e into a
position when its hook e¹ can re-engage with the shoulder of the hammer and
the engagement is ensured by a spring .
The magazine and mechanism for feeding or transferring the bullets or shots
from the magazine to the barrel, are shown in Figures 9 and 10. is a groove or
slotted tube arranged in the stock and extending for a convenient distance along
the barrel. In the forward extremity of this groove is a spring which presses
against a sliding piece or follower p² and moves or tends to move the said follower
towards the rear end of the magazine. A projection is provided on the follower
by means of which the said follower can be moved to and fro in the magazine tube
by hand. is an enlargement provided in the slot to allow of charging the
magazine tube with the shot or bullets. The sliding piece or follower is pushed
forward when the magazine is charged, the spring p₁ being thereby compressed and
storing up energy by which the feeding of the projectiles is accomplished. is a
revolving cylinder pivoted at q' and having recesses or chambers q² which receive
the bullets or shots from the magazine when passing the opening thereof. * is a
plate pivoted at and having a projection 2 on it. This plate carries a spring
pawl pivoted at the said pawl being adapted to engage with depressions q³ in
the edge of the cylinder. A second hooked pawl s pivoted at s also engages with
the said depressions thus preventing the cylinder from turning backwards when the
pawl is dragged back. The action of the device is as follows, when the hammer
is cocked, its forward and upper part d' presses on the projection 2 of the plate
and partially rotates the said plate about its pivot causing the pawl to rotate the
cylinder through a distance just sufficient to bring the next chamber containing
bullet into line with the barrel of the gun, and also an empty chamber into position
behind the magazine so as to take therefrom a fresh bullet.
When the gun is
discharged and the hammer flies back and releases the plate the latter is turned
backwards by a spring thus dragging the pawl ³ round the cylinder until it engages
a fresh depression in the periphery thereof, the cylinder being meanwhile prevented
from turning backwards by means of the second pawls as hereinbefore mentioned.
The parts are now in a position for being operated again when the hammer is next
cocked, and the operations above described are then repeated.
r
a
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
First. In a gun worked by compressed or liquefied gas, the arrangement of the

page_text: reservoir in the butt or stock of the gun behind the barrels in combination with a
hammer or striker that moves backward away from the barrels when released by
the pulling of the trigger.
Second. A double-barrelled gun worked by compressed or liquefied gas and so
constructed that one reservoir having but one valve or vent serves both barrels,
substantially as described.
Third. The construction and arrangement of the parts of a double-barrelled
sporting gun or rifle operated by compressed or liquefied gas substantially as
described with reference to Figures 5, 6 and 7.
Fourth. The hammer and trigger so constructed and arranged that in the
backward movement of the trigger the hammer is first raised or cocked and then
released, substantially as described with reference to Figure 8.
Fifth. The means for transferring the bullets or shots from the magazine to the
barrel of the gun, substantially as described with reference to Figures 9 and 10.
Sixth. A gun constructed and arranged substantially as described with reference
to Figures 1 to 4, and operating as specified.
Dated this 9th day of January 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.