Improvements relating to Machine-guns and other Fire-arms and to Apparatus to be Used in the Manufacture thereof.
Year: 1886

page_text: Date of Application, 13th Oct., 1886
Complete Left, 13th Aug., 1887
Complete Accepted, 13th Oct., 1887
Improvements relating to Machine-guns and other Fire-arms and
to Apparatus to be Used in the Manufacture thereof.
I, HIRAM STEVENS MAXIM, of 57D Hatton Garden, in the County of Middlesex,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates chiefly to that class of guns for which numerous patents have
already been granted to me, and which are now well known as automatic guns. It
also relates to apparatus to be used in the manufacture of such guns.
My said invention comprises various improvements hereinafter set forth which are
applicable to machine or battery guns, to military rifles and other small-arms, and
also to large and heavy guns or ordnance.
In the specification of former Letters Patent granted to me and dated 29th January
A.D. 1885, No. 1307, I have described an automatic gun wherein the barrel is firmly
attached to an inner frame and is arranged to recoil therewith in an outer frame or
support, the breech-block being fitted to slide longitudinally to and fro in the said
inner frame. In the specification filed with my application for provisional protection
dated 1st June A.D. 1886, No. 7354, I have described an automatic gun of this kind
or class wherein the breech-block is locked to the barrel and inner frame and, at each
discharge, recoils therewith. through a distance slightly greater than the length of a
cartridge, and, at the termination of such recoil, is unlocked and is then held back,
during the forward movement of the barrel and inner frame, to effect the extraction
of the empty cartridge-shell and to permit the transfer of a fresh cartridge from the
magazine into position to be thrust into the barrel by the breech-block.
My present mprovements are chiefly designed to further simplify and improve the
construction of guns of this kind or class.
An important feature of my present invention is the employment of a wedge or
block, which is arranged to move perpendicularly to the axis of the barrel, and
whereby the breech-block is locked to the barrel when the breech is closed. This
wedge or block is carried by, and travels with, the breech-block.

page_text: My present invention, moreover, comprises the construction and arrangement of the
parts in such a manner that, when the barrel and breech-block have recoiled through
a distance equal to about one half of the desired length of the stroke or movement of
the breech-block, the latter will be unlocked from the barrel and its continued
backward movement will be effected, during the forward or return movement of the
barrel, by energy stored, during the recoil, in a spring or springs connected with the
said barrel.
In some instances, I provide the barrel and the breech-block with racks geared with
a pinion arranged between the said racks; and I provide means whereby the said
pinion, although free to recoil with the barrel, will be held back at the termination of
such recoil, so that, in the forward movement of the barrel, the said pinion will be
rotated and thus caused to move back the breech-block. I also provide means
whereby the said pinion will be subsequently released and permitted to move forward
with the breech-block.
In other instances, I employ hydraulic apparatus so constructed and arranged that,
in the forward or return movement of the barrel, water will be forced from one
chamber into another chamber and caused to act upon a piston to move back the
breech-block.
Another feature of my present invention is the combination, with a vertical hopper,
feeder or magazine, of means whereby the cartridges will be supported therein in
such a manner that, in each recoil or backward movement of the breech-block, a
cartridge in the said magazine will be released and permitted to fall into position in
front of the said block, without the release of the remaining cartridges in the
magazine.
I
When the gun is to be supported upon a tripod or carriage, I provide for cooling
the barrel by means of water contained in a reservoir arranged above, below, or at
one side of the barrel, instead of around the same as heretofore. For this purpose,
arrange a suitable casing around the barrel, and combine, with the said casing and
reservoir, means whereby, at each discharge, a small quantity of water will be
admitted from the said reservoir into the said casing. The admission of water to the
casing is effected by the pulling of the trigger, or by the barrel or other part either in
its recoil or in its forward or return movement, or in any other convenient manner;
the water is permitted to flow by gravity from a reservoir above the barrel into the
casing around the same; or it is forced into the said casing, from a reservoir beneath
or at one side of the barrel, by means of compressed air, or by means of a pump, the
piston of which consists of an enlargement of the barrel, or which is provided with a
separate piston connected with the barrel or other moving part.
In some instances, I provide means whereby the opening or openings for the
passage of the water may be increased or diminished at will to regulate the speed of
firing.
When the gun is of large size, I prefer to make the barrel as follows, that is to
say: I take a steel forging of the required dimensions and either solid or hollow and
bore the same so that its internal diameter is a small fraction of an inch less than the
desired diameter of the finished bore. I then place the barrel, in its rough state, in
an upright position within a furnace, and I take two or more girders or columns
provided with projections and place the said girders or columns vertically outside the
furnace in such a manner that the said projections extend through the walls of the
furnace and bear firmly against the sides of the barrel for the purpose of keeping it
straight while in the fire. These girders or columns must be of great strength and
stiffness and are each provided with one or more supports which may be moved inward
until the said projections bear against the sides of the barrel.
I combine, with the said girders or columns, a strong platen and a hydraulic
cylinder, whereby longitudinal pressure may be applied to the barrel. The barrel is
cooled from the inside by a stream of water which is caused to pass through the same.
For this purpose suitable connections are made for the inlet of water at the bottom
and for the escape of hot water and steam at the top.
At the instant of allowing the water to enter at the bottom, a strong pressure is

page_text: applied to the barrel longitudinally to prevent the formation of cracks on the inside
thereof. As the inside cools and shrinks, it must either become stretched or else
shorten the outside of the barrel. To assist the compression and shortening of the
outside of the barrel (which is hotter than the inside thereof), during the process of
cooling, I use hydraulic pressure as above described.
For the purpose of cooling the barrel, in the above described process, I employ a
large tank, which is situated outside the furnace, and which, to commence with, is
filled with hot water. The top of this tank is connected with the bottom end of the
barrel and the bottom of the tank with a cold water supply. The water as it enters
the barrel will, therefore, be hot at first and will then become colder and colder as the
hot water is displaced in the tank by the cold water; and, when all the hot water is
exhausted, there will be a stream of cold water passing through the barrel. When
the gun has been so far cooled as to be only a dull red on the outside, the furnace is
allowed to cool, while the water is still flowing.
In some instances, I provide for cooling the barrel, in the above described process
by means of oil which is caused to circulate through the same.
For this purpose, I
provide an oil-tank, through which extend a number of tubes like those of a surface
condenser. The bottom of this tank is connected with a centrifugal or other pump
which is arranged to deliver into the bottom of the barrel. The top of the barrel
communicates with the top of the said tank. Cold water is caused to circulate
through the said tubes to cool the oil which comes from the barrel before it returns
thereto.
When the gun is of very large size, I sometimes form the barrel of two or more
lengths or pieces, each of which is made and cooled in the manner above described.
After these pieces are fitted one to another, an outer tube is heated and shrunk on to
the same.
My improved gun is very advantageous for use with cartridges of the kind or class
described in the specification filed with my application for Provisional protection
dated October 2nd A.D. 1886, No. 12,561.
I will hereinafter describe a gun constructed according to my present improvements
and chiefly designed for use with the said cartridges. In this gun, the barrel is fitted
to slide to and fro in suitable guides in a frame or support as described in my said
specifications No. 1307 and 7354. A spiral spring is placed upon the barrel within
an extension of the said frame, and bears, at one end, against the said frame, and, at
its other end, against a shoulder on the barrel, so that it will effect the return
movement of the latter. Or one or more springs are otherwise suitably arranged for
the purpose.
The breech-block is fitted to slide to and fro in suitable guides in the gun-frame
and is provided with one or more springs for effecting its forward or return movement.
A wedge-shaped or other block is fitted to slide up and down in guides formed on, or
attached to, the back of the breech-block, and is adapted to engage with shoulders or
projections on the barrel, when the breech is closed, and thus lock the breech-block to
the barrel. The said wedge or block is provided with antifriction rollers, and inclined
surfaces are formed on the inner sides of the said frame, so that, in the recoil of the
barrel and other parts, the said rollers will ride up the said inclined surfaces and the
wedge or block will thus be moved upward to unlock the breech-block from the barrel.
One or more springs are provided, which will be extended by the said wedge or block
in its upward movement and will react, at the termination of the forward or return
movement of the breech-block, to draw down the said wedge or block into its locking
position. A suitable switch pivotted to the gun-frame in such a manner that the
aforesaid antifriction rollers will raise the same and pass under it in their rearward
movement, but will, in their forward or return movement, pass over the said switch.
The said wedge or block is thus held up, in the forward movement of the breech-
block, until the breech is closed.
A rack is formed upon the underside of the barrel and is geared by means of a
pinion with a similar rack attached to the breech-block. This pinion is, under normal
conditions, free to roll between the said racks, but it is provided with a lever which,

page_text: when the barrel has recoiled through the desired distance, will engage with a shoulder
or stop on the gun-frame and prevent the forward movement of the said pinion. By
this time, the breech-block has been unlocked from the barrel. The barrel is then
moved forward by the reaction of its spring, and, acting upon the breech-block
through the medium of the said pinion, moves the said breech-block back, thus
opening the breech and extracting the empty cartridge-shell, which falls through an
aperture in the gun-frame. As soon as the breech-block has reached the rear end of
its stroke or movement, a projection on the barrel strikes the said lever and releases
the said pinion so that it is free to move forward with the breech-block.
The hammer and firing pin are so arranged within the breech-block that they will
be cocked in the upward movement of the aforesaid wedge or block, but cannot be
released until the said wedge or block is in its locking position.
Two sears are provided which engage with the firing pin, and one of which is
arranged to be disengaged from the said firing pin by the said wedge or block in the
latter part of its downward movement. The other sear is connected with a trigger so
that it can be disengaged from the firing pin by hand.
The magazine is attached to the top of the gun-frame, this frame is formed with an
aperture through which the cartridges will fall by gravity when released as hereinafter
described. The cartridges in the magazine are supported, at their forward ends, by
the sloping end of the magazine, and, at their rear ends, by a sliding piece acted upon
by a spring which tends to keep the said piece in engagement with the lowermost
cartridge. This sliding piece is arranged to be moved backward by the aforesaid
antifriction rollers so that, when the breech-block has terminated its rearward
movement, a cartridge will be permitted to fall from the magazine into position in
front of the breech-block. To support the column of cartridges in the magazine
while the lowermost cartridge is falling therefrom, I provide levers or pawls which
are pivotted to the sides of the magazine and extend through slots therein, so that
they project between the lowermost cartridge and the cartridge immediately above
the same.
In the forward movement of the breech-block, after the aforesaid sliding
piece has resumed its normal position, these levers or pawls are withdrawn by
projections on the barrel to permit the descent of the column of cartridges until the
said cartridges are supported by the said sliding piece. Or I provide other suitable
means for effecting the desired object.
In some instances, I provide a device for receiving and supporting the cartridges
when they fall from the magazine into the loading position. This device consists of a
bent bar fitted to slide in suitable guides on the outer frame or on the barrel and
provided with a spring, so that, when the breech-block moves away from the barrel,
the said bar will be pushed back by its spring to receive and support a cartridge;
the breech-block, in its forward movement, will push the said bar forward with the
said cartridge. One end of the said bar forms part of the seating for a cartridge in
the barrel.
If desired, the gun is provided with hydraulic or other buffers for diminishing the
shock produced by the recoil.
Dated this 12th day of
100
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.

page_text: to Apparatus to be Used in the Manufacture thereof.
I, HIRAM STEVENS MAXIM, of 57D Hatton Garden, in the County of Middlesex,
Mechanical 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 :-
My invention relates to automatic and other guns or fire-arms, and to apparatus to
be used in the manufacture thereof.
My said invention comprises various improvements hereinafter set forth, certain of
which are applicable to machine or battery guns, to military rifles and other small-
arms and also to large and heavy guns or ordnance
In the specifications of former Letters Patent granted to me and dated January 29th
A.D. 1885; No. 1307, and June 1st A.1). 1886, No. 7354, I have described
automatic guns wherein the barrel and breech-block are locked together and, at each
discharge, recoil within a stationary frame or support. In the said Specification
No. 1307, I have described a gun wherein the breech-block is unlocked from the barrel
during the recoil and then moves backward therefrom at a higher relative velocity, in
order to extract the empty cartridge-shell and permit the introduction of a fresh
cartridge between the barrel and breech-block, so that the said cartridge will be
thrust into the barrel by the breech-block in its forward or return movement. In the
said Specification No. 7354, I have described a gun wherein the breechi-block is
unlocked from the barrel at the termination of the recoil, and the barrel and breech-
block are then moved in opposite directions for the purposes above specified.
My present improvements are chiefly designed to further simplify and improve the
construction of guns of the last named kind or class.
An important feature of my present invention is the employment of a block or piece
which moves to and fro with the breech-block and whereby the breech-block is locked
to the barrel when the breech is closed, and which is arranged to be operated in the
to-and-fro movement of the breech-block to unlock the same from, and lock it to the
barrel. The said block or piece is, in some instances, fitted to slide in or upon
the breech-block perpendicularly to the axis of the barrel. It may, however,
be arranged to operate in any other suitable manner for the purposes above
specified.

page_text: My present invention, moreover, comprises the construction and arrangement of the
parts in such a manner that, after the breech-block has been unlocked from the barrel
at the termination of the recoil, its continued backward movement will be effected,
during the forward or return movement of the barrel, by energy stored up, during
the recoil, in a spring or springs connected with the said barrel.
In some instances, I provide the barrel and the breech-block with racks geared with
a pinion arranged between them, and I provide means whereby the said pinion,
although free to recoil with the barrel and breech-block, will be held back at the
termination of such recoil, so that, in the forward movement of the barrel, the said
pinion will be rotated and thus effect the continued backward movement of the breech-
block. I also provide means whereby the said pinion will be subsequently released
and permitted to move forward with the breech-block.
Another feature of my present invention is the employment, in combination
with a vertical hopper, feeder or magazine, of means whereby the cartridges will
be supported therein and; in each recoil or backward movement of the breech-block,
the lowermost of the said cartridges will be released and permitted to fall into
position in front of the breech-block, without releasing the remaining cartridges in
the magazine.
According to another part of my invention, I provide for cooling the barrel by
means of water or other suitable liquid contained in a reservoir arranged above,
below, or at one side of the barrel, and injected at intervals into a suitable casing
around the same. For this purpose, I combine, with the said casing and reservoir,
means whereby, at each discharge of the gun, communication will be established
between the said reservoir and casing by the pulling of the trigger, or by the move-
ment of the barrel or other part of the gun, or in any other convenient manner, so
that a small quantity of the water or other liquid may flow, under the action of
gravity, into the said casing, or may be forced therein by means of compressed air,
or by means of a pump, the piston of which consists of an enlargement of the barrel,
or which is provided with a separate piston connected with the barrel or other moving
part of the gun.
My said invention, moreover, comprises various other improvements hereinafter
set forth.
In the accompanying drawings,
Figure 1 is a vertical longitudinal central section of an automatic gun constructed.
according to my present invention.
Figure 2 is a transverse section on the line x, x, Figure 1.
Figure 3 is a sectional elevation of the said gun, drawn to an enlarged scale,
showing the parts in the positions which they occupy at the termination of the recoil.
Figure 4 is a similar view showing the parts in the positions which they occupy
when the barrel has returned to the firing position and the breech-block is about to
move forward.
Figure 5 is a similar view showing the parts in the positions which they occupy
when the breech-block has been driven home and again locked to the barrel.
Figures 6 and 7. show, in sectional elevation, a gun-barrel provided with means
hereinafter described for cooling the same while the gun is in use for firing.
Figure 8 is a transverse section on the line a', x', Figure 6.
Figure 9 is a side elevation, partly in vertical central section, showing apparatus
for cooling the barrel while the gun is in use for firing.
Figure 10 is a vertical central section of part of the said apparatus, drawn to an
enlarged scale.
Figure 11 is a vertical longitudinal central section showing a modification of my
invention.
Figure 12 is a vertical longitudinal central section showing another modification
thereof.
Figure 13 is a rear elevation, and,
Figure 14 is a transverse section, showing details of construction.

page_text: tempering or hardening gun-barrels.
Figure 16 is a vertical longitudinal central section illustrating another modification
of my said invention.
Figure 17 is a vertical longitudinal section, and
Figure 18 an end elevation showing details of construction.
Figure 19 is a vertical longitudinal central section, illustrating a further modifi-
cation of my said invention, and
Figure 20 is a transverse section on the line 2, 22, Figure 19.
Like letters indicate corresponding parts throughout the drawings.
A is a strong metal frame which is provided with trunnions A', and in which
the barrel B is fitted to slide substantially as described in my said former
specifications.
Cis the breech-block which is fitted to slide to and fro in grooves or guide-ways A2
in the frame A, and is provided with springs for effecting its forward or return
movement. C is a block or piece of metal which is wedge-shaped or slightly taper
vertically and is fitted to slide up and down in guides C³ formed on the back of the
breech-block C. This wedge or block is adapted to engage with shoulders or
projections B* on an extension B₁ of the barrel, when the breech is closed, and thus
lock the breech-block to the barrel. The said wedge or block is provided with anti-
friction rollers c, and inclined surfaces A³ are formed on the inner sides of the frame A,
so that, in the recoil of the barrel and breech-block, the said rollers will ride up the
said inclined surfaces, and thereby raise the wedge or block out of engagement with
the shoulders B* and unlock the breech-block from the barrel. A switch a is pivotted
at a to the gun-frame A in such a manner that the antifriction rollers c will raise the
same and pass under it in the recoil of the barrel and breech-block, but, in the forward
or return movement of the said breech-block, will pass over the said switch, so that
the wedge or block C will be held up during such forward or return movement until
the breech-block has returned to its firing position. To ensure the locking of the
breech-block to the barrel at the termination of the forward or return movement of
the said breech-block, a spring c¹ is attached at one end to the said wedge or block
and at its other end to the breech-block, so that it will be extended when the said
wedge or block is raised during the recoil, and, when the breech-block has returned
to the firing position will, by its reaction, draw down the said wedge or block into
its locking position.
A spring a² is enclosed within an extension A* of the frame A, and bears at one
end against the said frame and at its other end against a shoulder B² on the barrel, so
that it will be compressed during the recoil and energy will thus be stored up in the
said spring, which, by its reaction, will effect the forward or return movement of
the barrel.
D is a rack which is formed or fixed on the underside of the barrel B and is geared,
by means of a pinion D¹ with a similar rack D2 formed or fixed on an extension C*
of the breech-block C. A bent lever d is pivotted to the axle of the pinion D', and a
shoulder or stop a³ is formed on the frame A so that, when the barrel has recoiled
through the desired distance, the lower arm of the said lever will engage with the said
shoulder or stop a³ and will prevent forward movement of the pinion B until released
by means of a stud or projection d' on the barrel, as hereinafter described.
c² is a cocking lever, the short arm of which engages a notch in the firing pin e,
and the other arm of which is adapted to enter a slot or recess in the wedge or block C²,
so that the firing pin will be cocked in the upward movement of the said wedge or
block and will be held by the latter in its cocked position until the breech-block is
again locked to the barrel.
el is a safety sear one end of which engages with a notch in the lower end of the
wedge or block C and the other end of which is adapted to enter a notch in the
firing pin e and prevent the release of the said firing pin until the breechi-block is
locked to the barrel. e² is another sear adapted to enter a notch in the firing pin and

page_text: connected with the trigger E through the medium of the lever E' and rod E² so that
it can be disengaged from the firing pin by hand.
"
F is the main spring one arm or part whereof bears against a shoulder or projection
on the firing pin and the other arm or part whereof is divided and bears against the
sears eG is the magazine which is attached to the top of the gun frame A ;
the said frame being formed with an aperture in the top thereof through which the
cartridges from the magazine will fall by gravity when released as hereinafter
described. The cartridges in the magazine G are supported, at their forward ends,
by the sloping end of the said magazine, and, at their rear ends, by a sliding piece Gi
acted upon by a spring g which tends to keep the said piece in engagement with the
flange of the lowermost cartridge in the magazine. This sliding-piece is provided
with a projection g¹ on its under-side to be acted upon by the antifriction rollers c
during the latter portion of the rearward movement of the breech-block, so that the
sliding piece G will be moved backward a sufficient distance to allow a cartridge to
fall from the magazine into position to be thrust into the barrel by the breech-block
in its forward movement. To support the column of cartridges in the magazine
while the lowermost cartridge is falling therefrom, levers or pawls H are pivoted to
lugs formed on the sides of the magazine G and extend through slots G² in the said
magazine, so that they may be caused to project between the lowermost cartridge and
the cartridge immediately above the same in the said magazine. The sliding piece G¹
has attached thereto two arms or projections I, which slide in guide-ways i formed
in the magazine G. Each of the said arms or projections I is provided with a slot J
in which works a pin or stud H³ fixed in the corresponding lever or pawl H as shown
in Figure 2. When the barrel or breech-block recoil and the sliding piece is moved
backward, to allow the lowermost cartridge to fall into position in front of the breech-
block, the forward ends of the levers or pawls H will be moved inward and inserted
between the said lowermost cartridge and the one above it and will thus support the
remaining cartridges in the magazine. The levers H are enclosed by a casing K
which is secured to the magazine G.
Lis a stop formed on or attached to the frame A for arresting the movement of
the barrel when it has recoiled through the required distance.
M is the extractor which is carried by and pivoted to the breech-block, the pin
upon which it is pivotted passing through a slot in the said extractor so that the
breech-block will move a short distance backward before commencing to extract the
empty cartridge shell. The frame A is open at its under side so that the cartridge-
shells when extracted will fall from the gun.
The gun is provided with a pistol-butt or handle N (part only of which is shown in
the drawings) for facilitating the firing of the gun by hand.
The operation of the improved gun is as follows, that is to say :-The parts are
shown in Figure 1 in the positions which they occupy when the trigger has been
pulled and the projectile is about to move forward in the barrel. The force created
by the explosion of the cartridge in the barrel causes the recoil of the barrel and
breech-block. In this recoil, the antifriction rollers c ride up the inclined surfaces A³
thus raising the wedge or block C, so that, by the time the barrel has terminated its
recoil, the breech-block is unlocked from the barrel. By this time, moreover, the
firing pin has been cocked by the said wedge or block in its upward movement and
the lever d has arrived in position to engage with the shoulder or stop a² as shown in
Figure 3. The barrel is then moved forward by the reaction of the spring a² and
the rack D acts upon the pinion D³ which, as it is prevented from moving forward,
is rotated upon or about its axis, and, through the medium of the rack D2 moves the
breech-block backward, thus opening the breech and extracting the empty cartridge-
shell, which falls through the opening in the underside of the gun-frame. In the
backward movement of the breech-block, the rollers c act upon the projection g' and
move back the slide G¹ thus permitting the lowermost cartridge in the magazine to
fall in front of the breech-block, the remaining cartridges in the magazine being held
up by the pawls H as above described. As soon as the breech-block has reached the

page_text: rear end of its stroke or movement and the barrel has returned to its firing position
the stud or projection d' on the barrel strikes the lever d and releases the pinion D'
so that it is free to move forward with the breech-block. The breech-block is then
moved forward by the springs C¹ and thrusts the cartridge in front of it into the
barrel. The rollers e run along the top of the switch a until the breech-block is
driven home, the wedge or block C² is then moved down, under the action of gravity
and of the spring e, into position to again lock the breech-block to the barrel. The
said wedge or block, at the termination of its downward movement, disengages the
sear e¹ from the firing pin. If the sear e² is held out of engagement with the firing
pin by means of the trigger E, the gun will continue firing as long as it is supplied
with ammunition if, however, the trigger is released after pulling it to fire one shot,
it must be again pulled in order to fire another shot.
The gun shown in the drawings is specially designed for use with cartridges of the
kind or class described in the Specification of former Letters Patent dated October 2nd
A.D. 1886, No. 12561. It is obvious, however, that my improved gun may be
adapted for use with other cartridges.
Other suitable means may, if desired, be provided for supporting the cartridges in
the magazine and permitting them to fall successively in front of the breech-block.
It is evident that the construction and arrangement of the parts in such a
manner that, after each recoil, the forward or return movement of the barrel and
the continued backward movement of the breech-block will be simultaneously
effected by energy stored in a spring or springs during the recoil, can be
advantageously applied to military rifles and other small arms and also to large
and heavy guns.
If desired the gun is provided with hydraulic or other buffers for diminishing
the shock produced by the recoil.
In some instances, I make the vertically sliding wedge or locking block with a
series of projections adapted to engage with similar projections on the extension B¹
of the barrel so that the said block will only require to be moved a short distance
to unlock the breech-block from the barrel.
To provide for cooling the barrel of a gun when in use for firing. I employ
apparatus such as that shown in Figures 6 to 14.
Referring to these Figures O is a casing which is firmly attached to the gun-
frame A and which surrounds the barrel B. O is a tube which is fixed upon the
barrel and slides therewith in the said frame. A pipe or passage o extends from the
casing to a reservoir 02 (Figures 9 and 12) and is provided with a valve o'. The
reservoir Ois designed to contain water or other suitable liquid for cooling the barrel,
and is formed in the gun carriage or mounting as shown; I can, however, employ a
reservoir made separately from the carriage or mounting and attached thereto in any
convenient manner. The valve o consists of a rod or spindle having a conical end
and extending through a stuffing-box 03. The said valve is to be connected in any
suitable manner with the trigger of the gun so that it will be opened by the said
trigger when pulled to fire the gun, and will be closed when the trigger is released.
The reservoir O Figures 9 to 12 has a pipe 0* extending from the top to, or nearly
to, the bottom thereof.
The tube O is made with an elongated slot 0* so that there will always be an
opening for the flow of the water or other liquid from the pipe or passage o into
the said tube notwithstanding the to-and-fro movement of the barrel. To provide
for effectually cooling the rear part of the barrel, this tube is made to extend to
the breech end thereof, and is closed at its forward end by a ring or annular
piece of having a small aperture 06 above the barrel, and also, if desired, at each
side thereof. Therefore the water which enters the tube 0' must flow around the
breech-end of the barrel before it can escape from the said tube into the main
portion of the casing O. I prefer, moreover, to provide at suitable intervals along
the barrel B and casing O partitions formed of annular pieces 07 which divide the
said casing into compartments leaving apertures 08 above or at one or both sides of
B

page_text: the barrel to permit the flow of the water or other liquid from one to another of
the said compartments, these partitions are advantageously constructed as shown in
Figures 13 and 14, that is to say, a ring or annular piece 09 adapted to fit closely
around the barrel, is attached by means of distance pieces O", to another ring or
annular piece 010 designed to be secured in the casing O, and of such internal 5
diameter that, when secured in the said casing, it will not touch the barrel. The
distance pieces O" keep the said two rings or annular pieces apart and permit the
passage of the water or other liquid between them. By means of the above described
partitions, the flow of the liquid from the rear to the forward end of the casing O is
impeded or retarded. Suitable apertures are formed in the forward end of the
casing O, above the barrel, for the escape of the water from the said casing.
The reservoir O is to be partially filled with water or other suitable liquid, and air
is then to be pumped or forced therein until it is compressed to such an extent that,
by its expansion, it will force the liquid out of the reservoir through the pipe 04 into
the casing O when the valve o' is opened, therefore, when the trigger is pulled to fire
the gun a small quantity of water will be injected into the casing O, and will pass
through the said casing from end to end, thereby effectually cooling the barrel while
the gun is in use for firing.
To provide for the introduction of the liquid and the compressed air into the
reservoir 02 I insert in the side of the said reservoir a socket or hollow plug P
provided with a valve P' which opens inward and which is held upon its seat by a
spring P2. The said socket is, moreover, provided with a screw-cap or plug P3 for
tightly closing the same. To charge the reservoir 02, the screw-cap or plug P³ is first
removed, and the nozzle of a supply pipe is screwed into the socket P until its
extremity comes in contact with the outer end of the valve P¹ and pushes the said
valve away from its seat; the desired quantity of water is then introduced into the
said reservoir through this supply pipe. The said pipe is then removed from the
socket P and the spring P2, by its reaction, closes the valve P¹. Another pipe is then
connected with the said socket P and air is pumped or otherwise forced into the
reservoir O until the required pressure therein is attained, the valve P¹ permitting
the entrance of the air but preventing escape thereof.
I prefer to provide means whereby communication between the reservoir 02 and the
pipe or passage o will be automatically established in the act of placing the gun
upon its mounting. For this purpose I employ a device such as that shown in
Figures 9 and 10 in which P is a hollow cylinder screwed into the upper end of
the reservoir 02. P³ is a piston fitted to slide up and down in the said cylinder and
formed or provided with an extension or stem p which is fitted to slide in an aperture
or passage whereby communication is established between the said cylinder P* and
the reservoir 02. P is another piston also fitted to slide up and down in the
cylinder P above the piston P³. An india-rubber valve p¹ is inserted in the upper
end of the said cylinder and is firmly secured therein by means of a screw-cap P7.
The upper surface of the pinion Pe forms a scat for the valve p' and a spring p³ is
arranged between the pistons P5, P6, and tends to press the piston Pe upward against
the valve pt and to press the piston P³ downward.
P is a hollow stem which is screwed into a socket P° firmly attached to the
gun-frame and having the passage o¹ formed therein. This socket is adapted to
fit upon a casing P forming a part of the gun-mounting and surrounding the
cylinder P, the pistons P³, P³, have snall holes p', p² formed therein to permit the
passage of the water through the said pistons. The stem or extension p is, moreover,
cut away at p in such a manner as to form a passage for the liquids from the
reservoir O2 into the cylinder P*.
In the act of placing the gun on its mounting the hollow stem P³ which is perforated
at its lower end, is pushed through the valve p* and depresses the piston P*, thus
allowing the liquid to pass freely from the reservoir 02 into the passage o¹. When
the valve p is closed, the pressure in the cylinder P4 will be equal to the pressure in
the reservoir 02, therefore the piston P³ will remain at the lower end of its stroke.

page_text: When however, the valve p is opened as above described, water will flow from the
cylinder P into the casing around the barrel more rapidly than it can flow from the
reservoir through the hole p, consequently the pressure above the piston P³ will be
diminished and the said piston will rise, thereby compressing the spring p and
partially closing or contracting the passage p. As the pressures above the piston P³
increases, the spring, by its reaction, moves the said piston downward thereby
again opening the passage ps. The above described device therefore constitutes a
reducing valve, whereby the flow of water is accurately regulated or controlled as
required.
When the casing around the barrel is designed to be connected with the reservoir
by means of a suitable pipe, after the gun has been placed upon its mounting, I
provide means whereby, in the act of connecting the said pipe with the reservoir, the
communication between the said reservoir and the passage o' will be automatically
established. For this purpose I sometimes provide the reservoir with a valve fitted
to a seat in a socket or plug and held against its seat by a spring enclosed in a
chamber or cavity in the said screw-cap. And I provide the said pipe with a coupling
or union for connecting it with the said socket or plug. The said coupling is so con-
structed that its lower end will bear against the upper end of the valve stem and,
when the coupling is tightened, will open the said valve and keep it open until the
said coupling is slackened.
It will therefore be seen that, by the means above described, I provide for pre-
venting the flow of liquid from the reservoir, except when connected with the casing,
and for the automatic opening of the said valve in the act of connecting the said
reservoir and casing.
In some instances, I provide means whereby the opening or openings for the
passage of the water inay be increased or diminished at will to regulate the speed of
firing as hereinafter described.
When the gun is of large size, I prefer to make the barrel and to harden or temper
the same as follows, that is to say, I take a steel forging of the required dimensions,
and either solid or hollow, and bore the same so that its internal diameter is a small
fraction of an inch less than the desired diameter of the finished bore. I then place
the barrel, in its rough state, in an upright position within a furnace R, Figure 15.
Girders or columns R¹ are placed vertically outside this furnace and are provided with
struts R which extend through the walls of the furnace and are provided with means
for adjusting them, after the barrel has been placed in the furnace, so that they will
bear firmly against the sides of the barrel for the purpose of keeping it straight while
subjected to the heat of the fire. These girders or columns must be of great strength
and stiffness.
I combine, with the said girders or columns, transverse girders or cross-bars R³, R4,
and, on the lower girder R, I arrange a hydraulic ram S, whereby longitudinal
pressure may be applied to the barrel as hereinafter described. A strong platen S' is
placed on the said ram to support the barrel thereon, and a metal block S2 is placed
between the upper end of the barrel and the top girder R³.
The barrel is to be hardened or tempered by cooling it from the inside by means of a
stream of water or oil caused to pass through the same while it is subjected to the heat of
the furnace. For this purpose suitable connections are made for the admission of the
water or oil at the lower end of the barrel, and for the escape of the hot water or oil
and steam at the upper end thereof.
As the inside of the barrel is cooled, it will shrink, and must either become
stretched or else compress and shorten the outside of the barrel. To assist the com-
pression and shortening of the outside of the barrel (which is hotter than the inside
thereof) and to prevent the formation of cracks on the inside thereof, I apply strong
hydraulic pressure thereto as above described during the process of cooling.
I prefer to provide for cooling the barrel by means of oil which is caused to
circulate through the same as hereinafter described, that is to say:-I provide an oil-
tank T through which extend a number of tubes T¹ like those of a surface condenser.

page_text: The bottom of this tank is connected, by means of a pipe T², with a centrifugal
pump T3 which is arranged to deliver the oil into the bottom of the barrel through a
pipe T connected with the platen S' which is formed with a way or passage s. The
upper end of the barrel communicates, by means of a pipe T5, connected with the
block S3 which is formed with a way or passage s¹. Cold water is caused to circulate
through the space around and between the tubes T¹ to cool the oil which comes from
the barrel before it is again passed through the same. This water is admitted through
a pipe U and is discharged through a pipe U.
When the cooling of the barrel is to be effected by means of water, I employ a
large tank, which is situated near the furnace and which, to commence with, is filled
with hot water.
The top of this tank is connected by a pipe V with the lower end of
the barrel and the bottom of the said tank is connected with a cold water supply, an
escape pipe V being connected with the upper end of the barrel. The water as it
enters the barrel will, therefore, be hot at first and will then become colder and colder
as the hot water is displaced in the tank by the cold water, and, when all the hot
water has been forced through the barrel, a stream of cold water will pass through
the same.
When the gun has been so far cooled as to be only a dull red on the
outside, the furnace is allowed to cool, while the cold water is still flowing through
the barrel.
The barrel is to be subsequently bored to the required calibre.
When the barrel is very long, I sometimes form the same of two or more lengths
or pieces each of which is made and hardened or tempered in the manner above
described and which are then firmly united. After these pieces are joined one to
another, an outer tube is heated and shrunk upon the same.
In Figures 16, 17 and 18, I have shown a pump and devices whereby the same
will be operated in the to-and-fro movement of the barrel to draw liquid from a
tank or reservoir and force it into the casing O around the barrel. The breech-end
of the barrel B is fitted into a cylinder t at the rear of the casing O, and a piston-
ring or packing-ring t¹ is fitted in a groove in the said barrel. The cylinder t is
connected with the said tank or reservoir by means of a pipe or passage t* provided
with a check-valve 2 and with the casing O by means of a pipe or passage to provided
with a check-valve t¹. A sliding rod t is so arranged in combination with the
valve 2 that, when the barrel, after its recoil, returns to the firing position, a pro-
jection thereon (not shown in the drawing) will push forward the said sliding rod to
and open the valve t². The barrel, in its recoil, will draw liquid, from the tank or
reservoir through the said valve into the cylinder t, and will, in its forward or return
movement, deliver the said liquid through the valve t into the casing O.
To provide for regulating the speed of firing, I sometimes make the valve t¹ with a
screw-threaded spindle to extending through a stuffing-box t and provided with a
screw-nuts, by turning which in one or the other direction the lift of the said valve
may be increased or diminished and the velocity of the forward or return movement
of the barrel thus regulated.
t3
In the modification of my invention shown in Figures 19 and 20, a plunger u is
fixed in a bracket u formed on, or attached to the barrel B and extending downward
therefrom. This plunger works in a cylinder & connected with the water tank or
reservoir by means of a pipe or passage provided with a check-valve 2, and with
the casing by means of a pipe or passage t³ provided with a check-valve t. The
two ends of the said cylinder are, moreover, connected by means of a pipe or
passage v, the flow of liquid through which may be regulated by means of a rod or
plunger which is curved at its forward end as shown (or may be inclined if desired)
and which works in a stuffing-box v² at the rear end of the said pipe or passage v.
This rod or plunger is acted upon by a spring which tends to pull it outward. It
is connected, by ineans of a rod or bar , with a lever v pivoted at v to the rear end
of the frame A, a pin or stud 7 being fixed in one arm of the said lever and working
in a slot in the said rod or bar . The other arm of the said lever is coupled
to a screw-threaded rod extending through the rear end of the frame A and

page_text: provided with an adjusting nut 10. By turning this nut in one or the other
direction; the position of the forward end of the plunger relatively to the part " of
the passage v may be altered so as to increase or diminish the opening for the flow of
liquid from one to the other end of the cylinder t.
The plunger u is provided with a perforated piston ² held against a flange or
collar u on the plunger u by means of a spring u, substantially as described in my
said former specification No. 3844. The forward part of the cylinder t is of con-
siderably greater diameter than the piston u; the rear part of the said cylinder is,
however, of such diameter that the piston will fit and slide therein.
The operation of the device above described is as follows that is to say :- -Assuming
the parts to be in the firing position as shown and the whole of the available space in the
cylinder t and passage to be filled or nearly filled with liquid; in the recoil, the plunger u
will be partially withdrawn from the said cylinder and more liquid will thus be drawn into
the said cylinder from the tank or reservoir. As soon as the piston u² reaches the
smaller part of the cylinder t, the liquid behind the piston will flow through the
passage into the space in front of the said piston, or, should the said passage be
nearly closed by the plunger ', the spring u will be compressed and the liquid will
flow through the perforated piston 2. In the forward or return movement of the
barrel, the plunger u will be forced into the cylinder t; the holes in the piston u² will
be closed by the flange or collar u³, so that while the said piston is in the smaller part
of the cylinder, the liquid in front of the piston must flow through the passage vinto
the space behind the piston. The velocity of the forward or return movement of the
barrel and consequently the speed of firing will, therefore, depend upon the extent of
opening of the part of the said passage. The plunger u, as it is pushed into the
cylinder t, displaces some of the liquid therefrom and forces the same into the
casing 0, for the purpose of cooling the barrel as above specified.
It will be seen from the foregoing description that the speed of firing can be very
accurately regulated or determined by adjusting the nut 10.
It is evident that, if desired, a pump connected with the water tank or reservoir and
with the casing around the barrel may be combined with the trigger or trigger-rod in
such a manner that, when the trigger is pulled to fire the gun, it will operate the said
pump to draw liquid from the said tank or reservoir, and, when the trigger is released,
the said pump will be operated by the spring connected with the trigger, or by another
spring provided for the purpose, to force the said liquid into the said casing. Or the
operation of the said pump may be reversed so that liquid will be forced into the said
casing whenever the trigger is pulled to fire the gun.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is :-
First. A gun or fire-arm such as is hereinbefore referred to, wherein the barrel is
provided with a spring or springs, and the barrel and breech-block are connected by
suitable mechanism so that, after the recoil, the forward or return movement of the
barrel and the continued backward movement of the breech-block will be simultaneously
effected by energy stored up in the said spring or springs during the recoil.
Second. The employment, for locking the breech-block to the barrel, of a block or
piece which moves to and fro with the said breech-block and is arranged to be operated,
in the to-and-fro movement thereof, to unlock the same from, and lock it to the
barrel.
Third. The combination, with the sliding barrel and breech-block, of the wedge or
block which is carried by the breech-block and whereby the latter is locked to the
barrel, and means for moving the said wedge or block alternately in either direction
perpendicularly or transversely to the axis of the barrel, substantially as, and for the
purposes, set forth.
Fourth. The employment of a sliding locking wedge or block provided with a series
of projections adapted to engage with projections on the barrel, substantially as, and
for the purpose, set forth.

page_text: Fifth. The employment of rack-and-pinion mechanism whereby, when the barrel
and breech-block have recoiled, the continued backward movement of the said
breech-block will be effected during the forward movement of the barrel, for the
purposes above specified.
Sixth. The combination, with the sliding barrel and breech-block, of the racks
formed thereon, and the pinion gearing with the said racks and provided with the lever
adapted to engage with a shoulder or stop on the gun-frame and to be disengaged
therefrom by a stud or projection on the barrel, substantially as, and for the purposes,
set forth.
Seventh. The combination, with a gun provided with a vertical hopper or magazine,
of means whereby, in each recoil of the breech-block, a cartridge will be released
from the said magazine whilst the remaining cartridges will be held up therein until
the breech-block has moved forward, substantially as, and for the purpose, set forth.
Eighth. The employment of a switch, such as that shown at a, pivoted to the
gun-frame, substantially as, and for the purposes, set forth.
Ninth. The combination, with the locking wedge or block, of means whereby the
said wedge or block, when operated to unlock the breech-block from the barrel, will
cock the firing pin, substantially as set forth.
Tenth. The combination, with a locking block or piece carried by the breech-block
and operated in the to-and-fro movement thereof for the purposes above specified, of a
sear adapted to engage with the firing pin and so arranged that it will be disengaged
therefrom when, but not until the said block or piece is moved into its locking
position.
Eleventh. The improved automatic gun consisting of the parts constructed, and
combined substantially as described with reference to Figures 1 to 5 of the drawings
and operating as above specified.
Twelfth. The combination, with a gun having a chamber or casing around the barrel,
of means whereby, at each discharge of the gun, water or other liquid will be injected
into the said chamber to cool the barrel.
Thirteenth. The combination, with a gun having a chamber or casing around the
barrel, of a reservoir forming a part of, or attached to the gun carriage or mounting,
and a pump designed to be operated by the trigger or other moving part of the gun
for injecting water from the said reservoir into the said casing, substantially as, and
for the purpose, set forth.
Fourteenth. The combination, with a gun having having a chamber or casing around
the barrel, of a reservoir for containing water or other liquid and compressed air,
connected with the said casing by a pipe or passage provided with a valve coupled to
the trigger or other moving part of the gun, substantially as, and for the purpose,
set forth.
Fifteenth. The combination, with the reservoir for containing water or other liquid
and compressed air, of means for automatically regulating or controlling the flow of
liquid therefrom as required substantially as set forth.
Sixteenth. The employment, in combination with the reservoir for containing water
or other liquid and compressed air, of means for automatically opening and closing the
said reservoir when the gun is attached to and detached from its carriage or mounting,
substantially as set forth.
Seventeenth. The employment of the india-rubber valve in the reservoir, and the
hollow perforated stem attached to the gun and communicating with the casing around
the barrel thereof, substantially as, and for the purpose, set forth.
Eighteenth. The improved reducing valve constructed substantially as described
with reference to Figure 10 of the drawings for the purpose specified.
Nineteenth. The provision of means for regulating the flow of liquid from the said
reservoir into the chamber or casing around the barrel and thus controlling the speed
of firing, as above described.
Twentieth. The improved apparatus consisting of the parts constructed and combined
substantially as described with reference to Figures 6, 7 and 8 of the drawings,

page_text: whereby I provide for the cooling of the barrel during the operation of the gun,
as above specified.
Twenty first. The improved gun-mounting constructed with the reservoir,
substantially as described with reference to Figures 9 and 10 or to Figure 12 of the
drawings, for the purpose specified.
Twenty second. The above described improved method of hardening or tempering
a gun-barrel by cooling the same internally while heat is applied to its exterior and
while it is subjected to endwise pressure.
Twenty third. The manufacture of a gun-barrel by roughly boring a steel forging,
hardening or tempering the same by cooling it internally while heat is applied to its
exterior and while it is subjected to endwise pressure, and then boring it to the
required calibre, substantially as hereinbefore described.
Twenty fourth. The improved apparatus comprising the furnace, the girders or
columns, the hydraulic apparatus for applying endwise pressure to a gun-barrel, and
the means for causing a circulation of water or other liquid through the said barrel
while subjected to endwise pressure, substantially as, and for the purpose, set forth.
TARZ KA
HIRAM STEVENS MAXIM.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.