Improvements in Machine Guns.
Year: 1890

page_text: Date of Application, 28th June, 1890
Complete Specification Left. 25th Sept.. 1890-Accepted. 28th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in Machine Guns.
I, EMIL RITTER VON SKODA, of Pilsen, Bohemia, in the Austrian Empire,
Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention relates to a gun in which the energy of recoil produced by the
discharge, is transmitted to a fly-wheel, and the recoil of the gun is converted
into rotary motion, the energy stored up in the fly wheel effecting the advance or
return of the gun into its original position, and also all the operations necessary to
maintain uninterrupted automatic firing.
The transmission of the movement of the gun produced by the recoil to the fly
wheel may be effected by means of any suitable and usual means such as a crank
and connecting rod, an eccentric, a dog link, a cam, or a groove in a disc rotating
about the fly wheel shaft.
On the recoil of the gun, there take place, besides the action on the fly wheel,
a partial opening of the breech, ejection of the cartridge case, and cocking of the
lock, and the further rotation produced by the energy stored up in the fly wheel,
effects the complete opening of the breech, the introduction of a fresh cartridge,
closing of the breech, advance of the gun, firing the next shot, and the operation of
a pump for the purpose of cooling the gun barrel.
The energy stored up in the fly wheel after a shot is sufficient, even if several
shots should miss fire, to maintain in operation for some time, the entire breech and
firing mechanism of the gun, as well as the supplying of cartridges, and the operation
of the pump for cooling the gun barrel.
The connection between the fly wheel and the breech is such that the
opening and closing of the breech, during the recoil and advance of the gun barrel
will correspond with the ejection of the empty case and the introduction of a fresh
cartridge.
The annexed drawings illustrate a machine gun according to this invention.
Fig. 1 is a vertical longitudinal section of the gun with the breech closed,
and the percussion pin-lock in the cocked position it will assume at the moment of
firing.
Fig. 2 is a horizontal section of the same.
Fig. 3 is a vertical section on the line x x of Fig. 2.
Figs. 4 and 5 are cross sections on the lines ¹ x and x2 a² of Fig. 2.
Fig. 6 shows in longitudinal section the arrangement for guiding the gun barrel
in its cooling casing.
Figs. 7 and 8 are cross sections respectively of the rear and front ends of the
barrel and cooling casing.
Figs. 9 and 10 show the guiding frame of the gun barrel in vertical and in
horizontal longitudinal section.
Figs. 11 and 12 are cross sections respectively of the rear and front parts of this
guiding frame.
Figs. 13, 14 and 15, show the breech cylinder respectively in side elevation,
horizontal section, and rear elevation.
Fig. 16 shows the breech piston with the cocking piece in its position after
firing.
Figs. 17, 18 and 19 illustrate the arrangement of links by means of which the
recoil acting upon the breech cylinder is, on the recoil of the barrel, transmitted to
the fly wheel.
Fig. 20 illustrates diagrammatically the movement of these links during a
revolution of the fly wheel.

page_text: Figs. 21 to 27 show several arrangements of cases or holders adapted to be fixed
on a band and which serve for the reception and supply of the cartridges.
Figs. 28 to 48 illustrate diagrammatically several mechanical arrangements with
various breech closing devices, suitable for serving to transmit the energy of recoil
to the fly wheel.
The breech closing device, which can either be a cylindrical breech closure, as
shown in Figs. 1 to 20, or may be any closure usually employed in fire-arms, is
connected, as is also the gun barrel, with the fly wheel by means of mechanism
which transmits the rectilinear or curvilinear movement of the parts directly
acted upon by the recoil, to the fly wheel, and converts the same into rotary
motion, the direction of rotation of the fly wheel remaining always the same.
parts thus moved may remain in constant connection with one another, or may be
temporarily separated from one another and be returned into their position of rest
by means of independent spring power.
The
Cartridges may be supplied to these guns either by means of a hopper or loading
frame, or by means of a cartridge belt passing over a drum, the movement of the
drum being regulated at each shot and at the proper time by means of intermediate
mechanism actuated by the fly wheel.
The water-cooling of the gun tube or barrel is effected by means of a suitable
pump which is also operated by the fly wheel.
In a machine gun according to this invention as illustrated in Figs. 1 to 20 the
cylindrical breech closing device consists of a breech closing piston E inserted in
the guide of the gun barrel which is formed of a guide frame A (Figs. 9 to 12)
movable in the casing B.
The casing B is carried by trunnions 6 on a gun carriage of any suitable con-
struction, and is provided with a cross bolt b' (Fig. 1) with which the elevating
device may be brought into connection.
Into the front end of the guide frame A is screwed the gun tube or barrel A¹
which passes through stuffing boxes 62 of the casing B' that surrounds the gun
barrel for the purpose of water-cooling, so that it can move freely backwards and
forwards in the said casing (Figs. 6, 7, 8).
To the gun barrel guide frame A, there is pivotally connected by means of a
pin a, a joint-piece C, through which passes the crank pin d of a crank disc D
arranged laterally of the casing, so as to be capable of rotating. The crank pin
can move freely in a recess a¹ of the guide frame.
On the shaft d' of this crank disc Ď is keyed a fly wheel D' which runs on the
outer periphery of the shaft bearing whereby the fly wheel shaft d' is relieved
of the load (Fig. 3).
With this fly wheel or with the joint-piece C of the crank pin d the breech-
closing piston E is movably connected by means of the connecting rod c.
The fly
wheel shaft carries a handle or hand wheel d³, by means of which the fly wheel can
be rotated for the purpose of opening and closing the breech or for preparing for
firing.
In this operation, when the breech is closed, and the cartridge has been inserted,
the connecting rod c and the joint piece C assume an extended position, in which
position (Figs. 1 and 17) the nose c² of the connecting rod c allows the arm 1 of
the cocking piece, which is pivoted to the breech closing piston, to slide off, so
that the striking pin e¹ thus freed, is impelled forwards by the force of the firing
spring and the cartridge is fired, whereupon the cocking piece e assumes the
position shown in Fig. 16.
At the moment the projectile leaves the barrel A', the energy of the recoil
throws back the gun barrel with the breech closing piston E, and this movement
is by means of the connecting rod c and joint piece C, transmitted to the crank
pin d and the pin a, whereby the fly wheel is caused to rotate in the direction of
the arrow 2 (Fig. 1), and the gun barrel guide A with the gun barrel A' is caused
to move backwards.
The energy of recoil acts upon the crank pin d until the latter arrives in the

page_text: direction of the axis of the gun barrel at the dead point (Fig. 18) whilst during
the remainder of the travel of the crank, only the energy stored up in the fly
wheel comes into action.
с
Whilst the crank pin d is moving from the position Figs. 1 and 17 into that of
Fig. 18, the breech at first remains closed, and the barrel and the breech move
together backwards. As the connecting rod c is connected with the longer arm,
and the gun barrel guide A is connected with the shorter arm of the joint piece C
which is capable of rotation about the crank pin d, it results that the breech
closing piston has a rearward travel greater than that of the gun barrel or its
guide.
The breech closing piston has reached its extreme position in which the ejection
of the cartridge takes place as hereinafter described (open breech), when the joint
piece C has been moved backwards to the greatest extent by means of the crank
pin d (Fig. 19) but meanwhile the gun barrel A' has already begun its forward
movement. When the crank pin & moves from its position Fig. 19 into that
Fig. 17, besides the insertion of a cartridge into the loading chamber (as herein-
after described), the breech is closed; the gun barrel completes its forward
movement, when the crank pin intersects the axis of the barrel (see position
shown. in dotted lines in Fig. 19) whereupon firing takes place when the joint
pieces C c are in the extended position.
The joint pieces C c are protected in their lowest position (Fig. 19) by a plate a³
(Fig. 3) of the casing.
The rearward movement of the gun barrel and the extended position of the joint
pieces Cc immediately before firing, have for result that the breech practically
remains completely closed during firing up to the exit of the projectile from the
barrel.
The diagrammatic view (Fig. 20) shows the movements of the breech and gun
barrel with the link pieces. O to P represents the travel when the breech is
closed; P to Q the travel when the breech is open; Q to R the travel during the
ejection of the case; R to S the travel during the supplying of the cartridge; and
during the movement from S to O the cartridge is inserted, the breech is closed,
and a fresh shot is fired.
The numerals 1 to 12 indicate the movements of C and c during a revolution of
the wheel.
The rectilinear movement of the centre of rotation a of the joint piece C is shown
by the lines drawn towards the left hand from the points 1 to 12 of the crank
circle.
When the breech is being opened the cartridge whose rim is caught by the
cartridge extractor e is drawn out of the loading chamber and strikes against an
ejector pin a² (Figs. 2 and 10) projecting in the path of the breech closing piston,
whereby the cartridge is knocked downward by the cartridge extractor and is
ejected through an opening 63 (Figs. 2, 5 and 10) formed in the barrel guide A and
the casing B. A tappet 64 (Fig. 5) arranged on the casing, causes it to diverge
laterally and prevents it from being thrown too far.
The supply of cartridges may be effected by means of loading frames or cartridge
belts as already mentioned.
For this purpose there is arranged in the casing B and below the breech closing
piston E a star-shaped drum F (Figs. 1 and 5). This drum is rotated by a shaft g
by means of toothed wheel gearing (shown in Fig. 5 by dotted circles h¹).
The shaft g is driven by the crank disc D, (Fig. 3), which is provided at its
periphery with a helical groove d' in which a pinion g¹ fixed on the shaft
engages.
When the supply of cartridges is effected by means of a loading frame, there is
provided on the casing B a passage 65 (as indicated in dotted lines in Fig. 5 at the
left hand) from which the first cartridge enters by its own weight between two teeth
of the drum F, whereupon the said cartridge by the rotation of the drum arrives,
after the opening of the breech, in front of the path of the breech closing piston, so

page_text: that on the closing of the breech, the cartridge is caught by the breech closing
piston E and can be pushed into the loading chamber.
When the supply of cartridges is effected by means of a belt I (Fig. 1) there are
fixed on the latter, at equal distances apart, metallic casings i (Figs. 21 to 27) in
which the cartridges are inserted. The belt furnished with cartridges is laid upon
the drum F (Figs. 1 and 5), so that the ends i of the casings lie between the
teeth fof the drum.
The supplying of the cartridges by rotation of the drum is effected as already
described, and a star-wheel g² (Fig. 5) may be arranged on the shaft g whereby the
cartridges are better guided.
The casings which serve for the reception of the cartridges, have at the rear
end a rim which, according as the cartridge rim projects (Fig. 21) or is turned
down behind (Fig. 22), is swelled out (Fig. 23) or bent over (Fig. 24).
Instead of the rim, only one or more short portions 2 of the same may be employed
(Figs. 25 to 27).
The casings are open at top and are elastic, so that the cartridge cannot fall
out, but can be caught and pushed out by the breech closing piston.
During the opening of the breech the striking pin el is cocked by the arm 2 of
the cocking piece e striking against a shoulder 6 of the casing B, whereby the
cocking piece is rotated and the striking pin is drawn back by the arm 3.
Whilst the arm 2 slides over the shoulder, the nose c¹ in consequence of the
bending of the joint pieces Cc (Fig. 18) passes over the arm 1 of the cocking piece
and maintains the latter in the cocked position until the extended position of the
joint pieces Fig. 1, is reached, that is to say when the breech is closed, whereupon
the firing is effected by the release of the cocking piece.
In order that fresh water shall continually circulate in the cooling casing B1
(Fig. 6), the fly wheel D₁ is enclosed by a casing d³ (Fig. 3), the rear surface of
the former being provided with curved grooves de which open into an annular
passage d' of the casing d³, which passage communicates through a pipe d³ (Fig. 1)
with the water reservoir.
The water drawn by the pump through the pipe de is pressed against a passage d
situated at the outer periphery of the fly wheel casing, the discharge union d
(Fig. 1) of which passage communicates with the inlet union on the cooling
jacket B (Fig. 6).
The escape of the heated water takes place aroungement described any other
of the heated water takes place through a pipe 68 (Figs. 6 and 8).
suitable pump driven from the fly wheel may be employed.
For regulating the speed of firing there is provided on the fly wheel casing
Fig. 2 a brake, the brake block ; of which acts upon the periphery of the crank
disc D.
Between the brake block j and the bolt 2 which is capable of being screwed in
by means of a handle j¹, there is a spring j³, whereby the brake block can be
pressed with increasing pressure against the brake disc D.
If the screw be screwed in so far that its end passes directly upon the rim of
the brake spindle j, the fly wheel can be brought at once to rest.
The brake may also be constructed as a gravity or a hydraulic brake; in the
first case the weight being correspondingly varied, and in the second case the
cross-sectional area of flow of the cooling liquid being decreased in the known
manner.
(Fig. 1) is the back sight; ' (Fig. 6) is the front sight, and 69 (Fig. 1) are
bosses serving for the mounting of lubricator cups.
Instead of the cylinder breech closing device above referred to, any breech
closing device usually employed in fire arms may be operated by means of the
movements hereinbefore described.
Figs. 28 to 35 illustrate further examples for operating the breech closure by
means of the connecting rod.
Figs. 36 to 44 illustrate examples of arrangements for operating the breech

page_text: closure by means of a combination of the to and fro movement of the gun and the
rotation of the fly wheel shaft or by means of the latter alone.
In these figures the gun is moved by the connecting rod c2 and the breech by the
connecting rod c. In this case also, as in all the other cases herein described,
the connecting rod may be replaced by mechanisms referred to at the beginning,
suitable intermediate gears being inserted.
In Figs. 39 and 40, there is no travel of the gun and the breech closure alone
moves.
Figs. 45 and 46 serve to illustrate the movement of the breech closure by the
gun moved by recoil, in which only the gun is connected with the crank shaft, and
the movement of the breech closure is produced, the point p of the two-armed
lever P1 P2 being either attached to the frame by means of guide rods p, a or working
between two fixed points x y of the frame.
In all the cases hereinbefore described, a portion of the energy of recoil
may also be taken up by a spring which aids the further rotation of the fly
wheel.
This spring may act in any desired direction, and on any desired crank pins, or
on any desired moving parts, Fig. 28.
Buffers may also be provided at suitable points for softening the shock.
In Figs. 47 and 48, only the breech closure acts upon the crank shaft, whilst the
gun barrel is carried along only as long as there is gas pressure remaining in the
barrel. It will then, in consequence of the lever P striking against a, be released,
and be returned to the position of rest by the spring 4, whilst the breech closure
moves on and effects the other operations.
Dated this 28th day of June 1890.
EMIL RITTER VON SKODA.
By L. W., per F. B.
COMPLETE SPECIFICATION.
Improvements in Machine Guns.
I, EMIL RITTER VON SKODA, of Pilsen, Bohemia, Manufacturer, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to a gun in which the energy of recoil produced by the
discharge is transmitted to a fly wheel, and the recoil of the gun is converted into
rotary motion, the energy stored up in the fly wheel effecting the advance or return
of the gun into its original position, and also all the operations necessary to maintain
uninterrupted automatic firing.
The transmission of the movement of the gun produced by the recoil to the fly
wheel may be effected by means of any suitable and usual means, such as a crank
and connecting rod, an eccentric, a crank pin working in a slot, a cam, or a cam
groove in a disc secured to the fly wheel shaft.
On the recoil of the gun, there take place, besides the action on the fly wheel,
a partial opening of the breech, ejection of the cartridge case, and cocking of the
lock, and the further rotation of the fly wheel produced by the energy stored up in
the same, effects the complete opening of the breech, the introduction of a fresh
cartridge, closing of the breech, advance of the gun, firing the next shot, and the
operation of a pump for the purpose of cooling the gun barrel.
The energy stored up in the Hy wheel after a shot is sufficient, even if several
shots should miss fire, to maintain in operation for some time, the entire breech and
firing mechanism of the gun, as well as the supplying of cartridges, and the
operation of the pump for cooling the gun barrel.
The connection between the fly wheel and the breech mechanism is such that the
opening and closing of the breech, during the recoil and advance of the gun barrel

page_text: will correspond with the ejection of the empty case and the introduction of a fresh
cartridge.
The drawings filed with my Provisional Specification illustrate a gun according
to this invention.
Fig. 1 is a vertical longitudinal section of the gun with the breech closed, and the
percussion-lock in the cocked position at the moment of firing.
Fig. 2 is a horizontal section of the same.
Fig. 3 is a vertical section on the line a Fig. 2.
Figs. 4 and 5 are cross sections on the lines all and ² ² respectively of
Fig. 2.
Fig. 6 shows in longitudinal section the arrangement for guiding the gun barrel
in its cooling jacket.
Figs. 7 and 8 are cross sections respectively of the rear and front ends of the
barrel and cooling jacket.
Figs. 9 and 10 show the guiding frame of the gun barrel in vertical and in
horizontal longitudinal sections.
Figs. 11 and 12 are cross sections respectively of the rear and front parts of this
guiding frame.
Figs. 13, 14, and 15, show the breech cylinder respectively in side elevation,
horizontal section, and rear elevation.
Fig. 16 shows the breech bolt with the scar in its position after firing.
Figs. 17, 18 and 19, illustrate the arrangement of links by means of which the
recoil acting upon the breech bolt is, on the recoil of the barrel, transmitted to the
fly wheel.
Fig. 20 illustrates diagrammatically the movement of these links during a
revolution of the fly-wheel.
Figs. 21 to 27 show several arrangements of cases or holders adapted to be
fixed on a band and which serve to receive the cartridges and feed them into
the arm.
Figs. 28 to 48 illustrate diagrammatically several mechanical arrangements with
various breech actions suitable for serving to transmit the energy of recoil to the
flywheel.
As will be seen from the drawings, the breech action which can either be a
cylindrical breech action, as shown in Figs. 1 to 20, or may be any breech action
usually employed in firearms, is connected, as is also the gun barrel, with the fly
wheel by means of mechanism which transmits the rectilinear or curvilinear move-
ment of the parts directly acted upon by the recoil, to the flywheel, and converts
the same into a continuous rotary motion. The parts thus moved may remain in
constant connection with one another, or may be temporarily separated from one
another and be returned into their position of rest by means of independent
spring power.
Cartridges may be supplied to these guns cither by means of a hopper or loading
frame, or by means of a cartridge belt passing over a drum, a suitable movement
being imparted to the drum at each shot at the proper time by means of intermediate
mechanism actuated by the flywheel.
The water-cooling of the gun barrel is effected by means of a suitable pump
which is also operated by the flywheel.
In the machine gun according to this invention illustrated in Figs. 1 to 20
the breech action, constructed as a bolt breech action, consists of a bolt or breech
cylinder E inserted in the frame A, which is secured to the gun barrel and is
movable in the casing B.
The casing B is carried by trunnions 6 on a gun carriage of any suitable construc-
tion, and is provided with a cross bolt b¹ (Fig. 1) with which the elevating device
may be brought into connection.
Into the front end of the guide frame A is screwed the barrel A¹ which passes
through stuffing boxes 62 of the jacket B₁ that surrounds the gun barrel for the

page_text: purpose of water cooming, so that it can move freely backwards and forwards in the
said jacket (Figs. 6, 7, 8).
To the gun barrel guide frame A, there is pivotally connected by means of a
pin a, a link C, through which passes the crank pin d of a crank disc D arranged
laterally of the casing. The crank pin can move freely in a recess a¹ of the guide
frame.
On the shaft d' of this crank disc D is keyed a flywheel D' which runs on the
outer periphery of the shaft bearing d² whereby the flywheel shaft d' is relieved of
the load (Fig. 3).
With this flywheel, that is to say with the link C of the crank pin d, the breech
bolt E is movably connected by means of the connecting rod c. The flywheel
shaft carries a handle or hand wheel d³ by means of which the flywheel can be
rotated for the purpose of opening and closing the breech or for beginning firing.
In consequence of this rotation the connecting rod c and the link C assume, when
the breech is closed and the cartridge has been inserted, an extended position, in
which position (Figs. 1 and 17) the nose c¹ of the connecting rod c allows the arm 1
of the sear, which is pivoted to the breech bolt, to slide off, so that the striking
pin e thus freed, is impelled forwards by the force of the main spring e² and the
cartridge is fired, whereupon the sear e assumes the position shown in Fig. 16.
At the moment the projectile leaves the barrel A', the energy of the recoil
throws back the gun barrel with the breech bolt E, and this movement is, by means
of the connecting rod c and link C, transmitted to the crank pin d and the pin a,
whereby the flywheel is caused to rotate in the direction of the arrow = (Fig. 1),
and the gun barrel guide A with the gun barrel A' is caused to move backwards.
The energy of recoil acts upon the crank pin d until the latter arrives in the
direction of the axis of the gun barrel at the dead point (Fig. 18), whilst during the
remainder of the travel of the crank, only the energy stored up in the flywheel comes
into action.
Whilst the crank pin d is moving from the position Figs. 1 and 17 into that of
Fig. 18, the breech at first remains closed, and the barrel and the breech move
together backwards.
As the connecting rod c is connected with the longer arm, and the gun barrel
guiding frame A is connected with the shorter arm of the link or lever C which is
capable of partial rotation about the crank pin d, it results that the breech bolt
performs a rearward travel greater than that of the gun barrel or its guiding frame.
The breech bolt has reached its extreme position in which the ejection of the
cartridge takes place as hereinafter described (open breech), when the link C has
been moved backwards to the greatest extent by means of the crank pin d (Fig. 19),
but meanwhile the gun barrel A' has already begun its forward movement.
When the crank pin d moves from its position Fig. 19 into that Fig. 17, a
cartridge is pushed into the chamber of the barrel (as hereinafter described) and
the breech is closed; the gun barrel completes its forward movement, when the
crank pin passes across the axis of the barrel (see position shown in dotted lines
in Fig. 19) whereupon firing takes place when the links C c are in the
extended position.
The links C c are protected in their lowest position (Fig. 19) by a plate a
(Fig. 3) secured to the casing.
The rearward movement of the gun barrel and the extended position of the
links Cc immediately before firing, have for result that the breech practically
remains completely closed during firing up to the exit of the projectile from the
barrel.
The diagrammatic view, Fig. 20 shows the movements of the breech bolt and
gun barrel and the links. O to P represents the space corresponding to the breech
being closed, P to Q to the breech being open; Q to R the space during which
the ejection of the case takes place; R to S the space corresponding to the
supplying of the cartridge; during the movement from S to O the cartridge is
inserted, the breech is closed, and a fresh shot is fired.

page_text: The numerals 1 to 12 indicate the movements of C and e during a revolution of
the wheel.
The rectilinear movement of the pivot a of the link C is shown by the
lines drawn towards the left hand from the points 1 to 12 of the crank circle.
When the breech is being opened, the cartridge whose rim is caught by the
cartridge extractor e³ is drawn out of the chamber of the barrel and strikes
against an ejector pin a² (Figs. 2 and 10) projecting in the path of the breech
bolt, whereby the cartridge is loosened from the cartridge extractor and is
ejected through an opening 63 (Figs. 2, 5, and 10) formed in the barrel guiding
frame A and the outer casing B. A stop (Fig. 5) arranged on the casing,
causes it to diverge laterally and prevents it from being thrown too far.
The supply of cartridges may be effected by means of loading frames or cartridge
belts, as already mentioned.
For this purpose there is journaled in the casing B and below the breech bolt E
a star-shaped drum F (Figs. 1 and 5).
This drum is rotated by a shaft g by means of toothed wheel gearing (shown
in Fig. 5, by dotted circles h h').
The shaft 9. is driven by the crank disc D, (Fig. 3), which is provided at its
periphery with a helical groove d in which a pinion g¹ fixed on the shaft 9,
engages. This crank disc also serves as a brake disc as hereinafter described.
When the supply of cartridges is effected by means of a loading frame, there
is provided on the casing B, a sort of hopper 65 (as indicated in dotted lines
in Fig. 5, at the left hand) from which the first cartridge enters by its own.
weight between two teeth of the drum F, whereupon the said cartridge by the
rotation of the drum arrives, after the opening of the breech, in front of the
breech bolt, so that on the closing of the breech, the cartridge is caught by
the breech bolt E and pushed into the chamber of the barrel.
When the supply of cartridges is effected by means of a belt I (Fig. 1) there are
fixed on the latter, at equal distances apart, metallic casings i (Figs. 21 to 27)
in which the cartridges are inserted. The belt furnished with cartridges is laid
upon the drum F (Figs. 1 and 5), so that the ends i of the casings lie between the
teeth of the drum.
The supplying of the cartridges by rotation of the drum F is effected as already
described, and a star-wheel g² (Fig. 5) may be arranged on the shaft whereby
the cartridges are better guided.
The casings which serve for the reception of the cartridges, have each at
the rear end a rim i which, according as the cartridge rim projects (Fig. 21)
or is formed with an annular groove (Fig. 22), is swelled out (Fig. 23) or bent
over (Fig. 24).
Instead of an entire rim, one or more short portions 2 only of the rim may be
used (Figs. 25 to 27).
The casings are open at the top and are elastic so that the cartridge cannot fall
out, but can be caught and pushed out by the breech bolt.
During the opening of the breech the striking pin e¹ is cocked by the arm 2 of
the sear e striking against a shoulder 6 of the casing B, whereby the sear is rotated
and the striking pin is drawn back by the arm 3.
Whilst the arm 2 slides over the shoulder, the nose c', in consequence of the
bending of the links Ce (Fig. 18), passes over the arm 1 of the sear and maintains
the latter in the cocked position until the extended position of the links Fig. 1, is
reached, that is to say when the breech is closed, whereupon the firing is effected by
the release of the sear.
In order that fresh water shall continually circulate in the cooling jacket B1
(Fig. 6), the fly-wheel D₁ is enclosed by a casing a³ (Fig. 3), the rear surface of
the former being provided with curved grooves d' which open into an annular
passage d' of the casing d³, which passage communicates through a pipe d³ (Fig. 1)
with the water reservoir.
The water drawn by the pump through the pipe d8 is forced into a passage d

page_text: situated at the outer periphery of the flywheel casing, the discharge union d10
(Fig. 1) of which passage communicates with the inlet union 6' on the cooling
jacket B1 (Fig. 6).
The escape of the heated water takes place through a pipe 68 (Figs. 6 and 8)
whose upper end terminates at the upper portion of the jacket B'.
It is to be understood that instead of the arrangement described any other
suitable pump driven from the flywheel may be employed.
For regulating the speed of firing there is provided on the fly wheel casing
(Fig. 2) a brake, the brake block of which acts upon the periphery of the crank
disc D; or it may be upon the flywheel shaft, or upon the flywheel itself.
Between the brake block; and the screw 2, which is capable of being screwed
in by means of a hand wheel j', there is a spring 3, whereby the brake block can
be pressed with increasing pressure against the brake disc D.
If the screw be screwed in so far that its inner end presses directly upon the
shoulder of the brake spindle, the fly wheel can be brought at once to rest.
In Fig. 3 the disc D is shown turned through an angle of 180° and in engage-
ment with the wheel g¹ of the cartridge feeding device.
With this arrangement the engaging projection of the brake block is thrown out
of the groove of the disc D at every complete revolution of the latter.
This may however, if desired, be obviated in any desirable manner, as for instance
by using two parallel discs, or by providing the disc D with two grooves of which
one engages with the brake and the other with the feeding device or the like.
The brake may also be constructed as a gravity or a hydraulic brake; in the
first case the weight being correspondingly varied, and in the second case the cross-
sectional area of conduit through which the cooling liquid passes being decreased in
a manner that is known. k (Fig. 1) is the back sight; (Fig. 6) is the front
sight, and 68 (Fig. 1) are bosses serving for the mounting of lubricator cups.
Instead of the bolt breech action above referred to, any breech action usually
employed in fire arms may be operated by means of the movements hereinbefore
described.
Figs. 28 to 35 illustrate further examples of mechanisms for operating the breech
action by means of the connecting rod.
Figs. 36 to 44 illustrate examples of arrangements for operating the breech
action by means of a combination of the to and fro movement of the barrel and the
rotation of the flywheel shaft or by means of the latter alone.
In these figures the barrel is moved by the connecting rod ² and the breech
block by the connecting rod c³. In this case also, as in all the other cases herein
described, the connecting rod may be replaced by mechanisms referred to at the
beginning, suitable intermediate gears being inserted.
In Figs. 39 and 40, there is no travel of the gun, and the breech block alone
moves.
of*
Figs. 45 and 46 serve to illustrate the movement of the breech block by the
barrel moved by recoil; in these figures only the barrel is connected with the
crank shaft, and the movement of the breech block is produced, by the point
the bell-crank lever P1 P2 being either attached to the frame by means of a link p-
or working between two stops y formed on the frame.
In all the cases hereinbefore described, a portion of the energy of recoil may
also be taken up by a spring which aids the further rotation of the flywheel.
This spring may act in any desired direction, and on any desired crank pins,
or on any desired moving parts, see Fig. 28.
Buffers may also be provided at suitable points for softening the shocks.
In Figs. 47 and 48, only the breech block acts upon the crank shaft, whilst
the gun barrel is carried along only as long as there is gas pressure remaining
in the barrel. It will then, in consequence of the lever P¹ striking against t,
be released, and be returned to the position of rest by the spring 9, whilst the
breech block moves on and effects the other operations.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion, and the manner in which the same is to be performed, I declare that what I
claim is :-
1. A. machine gun having a fly wheel connected with the gun barrel in such a
manner as to receive and store up the energy of recoil and to be thereby caused
to rotate constantly in one direction, the energy thus stored up being utilised to
effect the return of the barrel to its original position and to operate the breech
action.
2. In a machine gun provided with a fly wheel as referred to in the preceding
claim, operating the breech action and cartridge extractor by the energy of recoil
stored up in the fly wheel, by means of (a) an oscillating connecting rod; or (b) by
the revolving crank-shaft and a suitably arranged crank pin; or (c) by the to and
fro motion of the gun barrel which is combined with a stationary part that is either
in constant connection with the breech' action or is connected only at intervals
with the breech action; or (d) by any suitable combination of the above men-
tioned means for transmitting motion.
3. In a machine gun of the kind referred to in claim 1, the combination with
the breech bolt E capable of movement along the gun barrel guide frame A, of a
link or lever C pivoted to the said guide frame and to a crank pin connected with
the fly wheel D¹ upon which the recoil acts in such a manner as to rotate the same,
and a connecting rod e so connected to the link or lever C, as to be in line with it
when the cartridge is fired, and afterwards to bend or form an angle with the
link or lever, the arrangement being such that the gun barrel and breech bolt at
first make a short recoil movement together and on the further rotation of the
fly-wheel the breech bolt effects the complete opening of the breech, the ejection
of an empty cartridge case, and afterwards the closing of the breech with simul-
taneous insertion of a fresh cartridge and the advance of the gun barrel as set
forth.
4. In a machine gun of the kind referred to in claims 1 and 2, supplying the
cartridges by means of a belt I that is mounted on a toothed drum F driven
by the fly wheel, and is provided with flexible casings that are open at top so
that the cartridges inserted in them can be caught by the breech bolt™ and
pushed out.
#1
5. In a machine gun of the kind referred to in claims 1 and 2, a sear e pivoted to
the breech block or bolt, and so arranged in relation to a nose c¹ on the connect-
ing rod c and to a fixed shoulder 66, that at the opening of the breech, the sear
is rotated by reason of its arm 2 striking against the shoulder 66 and thereby cocks
the striking pin, the arrangement being such that the nose c' of the connecting rod c
then moves over the arm 1 of the sear and keeps the striking pin cocked until
the breech is closed and the nose is drawn back from the arm 1 in consequence
of the connecting rod c being brought into line with the link C, when the gun is
fired.
637
TIL
6. A machine gun of the kind referred to in claims 1 and 2, constructed with an
adjustable brake subjected to variable pressure, and the brake block of which acts
upon the crank disc connected to the fly wheel, or upon the fly wheel shaft, or
upon the fly wheel itself, for the purpose of regulating the speed of firing.
7. In a machine gun of the kind referred to in claims 1 and 2,
projecting into the path of the breech bolt and against which a cartridge case strikes
whilst being drawn out of the chamber of the barrel by the cartridge extractor, so
that the said case is thereby ejected.
screw a²
8. A machine gun of the kind referred to in claims and 2, constructed with a
cooling jacket B' and with a pump operated by or from the fly, wheel D', the
arrangement being such that the pump can force water into the cooling jacket B¹
for the purpose of cooling the gun barrel as set forth.
9. My improved machine gun constructed arranged and operating substantially
102

page_text: as hereinbefore described with reference to and shown in Figs. 1 to 20 inclusive of
the drawings annexed.
Dated this 25th day of Santember 1890
EMIL RITTER VON SKODA.
By L. W., per F. B.