Improvements in Automatic Machine Guns.
Year: 1894

page_text: Date of Application, 12th June, 1894
Complete Specification Left, 13th Apr., 1895-Accepted, 24th May, 1895
Improvements in Automatic Machine Guns.
I, OSCAR WILLIAM BERGMAN, of Gothenberg, in the Kingdom of Sweden,
Lieutenant Royal Swedish Artillery, do hereby declare the nature of this invention
to be as follows:-
My invention relates to machine guns, the movements of the several parts of
which are effected by the to-and-fro movement of the parts under the action of the
recoil, means being provided whereby the gun can also be fired by hand.
The mechanism is enclosed in a frame provided with grooves in which several of
the parts slide and with bearings for the several rotating axles, and the frame is
closed by two covers, one covering the feeding apparatus, the other the rear end
of the gun. When these covers are open all the interior parts can be examined and
dismounted, and spare parts easily introduced.
The barrel which is adapted to recoil has screwed on to its rear end a breech
box containing the breech bolt, the said breech box being made in two parts
united in front for being screwed on to the barrel, and connected near the
middle and the end by stays or studs, and being adapted to slide in the grooves
in the frame.
At the rear end of the breech box is pivoted a lever having at one end a segment
of teeth (the said lever being hereinafter referred to as the segment lever) adapted
to engage with rack teeth on the frame and thereby cause the movement of the
segment lever during the to-and-fro movement of the parts. The other end of the
said lever engages in a slot in a cam (hereinafter referred to as the slotted cam)
the said slotted cam being pivotted to move in a vertical plane at or near the centre
of the frame.
The breech-bolt moves forwards and backwards in grooves cut in the sides of
the breech-box, and its rear part is slotted and carries a roller which is acted upon
by the slotted cam to give to the breech-bolt an additional movement to that of
the breech-box. The breech-bolt has a push rod which serves to eject the fired
cartridge cases. The breech-bolt is provided with percussion mechanism, and
extractor mechanism.
The percussion mechanism consists of a striker and a percussion spring, the
tail of the striker having a bar which is adapted to be engaged by the slotted
cam to draw back the said striker for compressing the percussion spring. In
front of the said bar is a hook with which a safety-catch engages and a notch
in which a trigger-catch engages. The striker slides in the upper part of the
breech-bolt.
The trigger-catch acts by a spring and is fitted to the side of the breech-bolt, and
when engaging in the notch of the striker it prevents the striker from being
displaced in relation to the breech-bolt before the latter has completely closed
the breech.
The trigger-catch is disengaged from the striker by being lifted by one of the
two locking blocks on the segment lever at the moment when the latter completes
its locking movement.
The said segment lever when the breech is closed, serves to lock the breech bolt
when the charge is fired.
The said segment lever is composed of two checks joined together by the pin
which slides in the slotted cam and each having teeth on the periphery. The

page_text: said cheeks move outside the sides of the breech-box and carry the two locking
blocks hereinbefore referred to, which blocks rise behind the breech-bolt when
the pin of the segment lever is raised by the pivotting movement. In this position
the locking blocks support the end of the breech-bolt and prevent it from recoiling
independently of the breech-box, thus locking the breech and carrying the pressure
of the discharge in a line with the axis of the barrel.
When the pin of the segment lever is in its lower position, the two locking blocks
are free from the breech-box, and the breech-bolt is free to execute its additional
movement for opening the breech under the action of the slotted cam.
The pivotting movement of the segment lever does not commence until a short
time after the explosion of the charge; to permit of this the rack with which
the teeth on one cheek of the segment lever engages is adapted to slide a short
distance, whilst the rack with which the teeth of the other cheek engages is made
of such a length that the teeth of the segment lever will only engage there-
with when the sliding rack has finished its movement, and the teeth of the two
racks coincide, when the teeth of both racks cause the complete pivotting movement
of the segment lever.
In the frame underneath the breech-box is placed a spring (hereinafter referral
to as the reversing spring) which spring stores energy during the recoil and after
each shot bring the parts forward to the firing position. One end of this spring
presses against a protruding part of the breech-box and the other against a shoulder
on a rod which serves for regulating the strength of the spring by means of a nut.
A pivotted spring stop is placed behind the slotted cam and the latter strikes against
it at the end of the recoil, in order to store the remaining energy of the recoiling
parts; as soon as the recoil is finished, the spring-stop gives back such energy and
helps to push the parts forward.
The feeding of the cartridges carried by a belt and the extraction and ejection
of the empty cases may be considered as six operations, viz.;
1. Transverse movement of the belt the distance between two consecutive
cartridges :
T
2. Pushing each cartridge forward out of the belt:
3. Moving the cartridges to a position behind the chamber of the barrel :
4. Inserting the cartridges into the breech chamber:
5. Extracting them from the chamber:
6. Ejecting each fired cartridge-case outside the machine-gun.
The cartridge belt consists of a number of elastic clasps fixed to a metal
band; the rear part of each clip firmly holds the cartridge, but allows of its being
pushed forwards by a projecting finger on the breech-box to disengage it from
the clip. Behind the clips is a stop which prevents the cartridge from moving
backwards. When desired the clips can be prolonged forwards so as to protect
and guide the bullet.
The clips are fixed to the flexible metal belt by covers of a form corresponding
with that of the clips, openings being formed in the metal belt between the
clips, with which openings the wings of a distributing drum engage to move the
belt transversely.
In order to make the belt as flexible as possible in all directions, the parts of
the band which join the clasps should be at or near the level of the axial centres
of the cartridges.
14
The distributing drum of the feeding apparatus is placed over the forward part
of the breech-box, and rotates on an axle parallel with the centre line of the
barrel in order to convey the cartridges from the point where they are pushed from
the clips to the breech chamber, several cartridges being carried forward at one
time. Each movement of the distributing drum brings one of the intervals between
the wings into line with the breech chamber, and allows the passage of the breech-
bolt for inserting the cartridge and for extracting the fired cartridge-case, thus
carrying out operations Nos. 4 and 5 mentioned above.
At the same time that the breech-bolt introduces a cartridge into the chamber

page_text: from between the two lower wings, another cartridge is disengaged from the belt
by the push-finger on the breech-box, but as the movement of the sail push-finger is
shorter than that of the breech-bolt, the disengaged cartridge is left free between
the two uppermost wings, thus accomplishing operation No. 2.
ז',
The empty cartridge-case is pulled back into the space between the wings from
which it was previously pushed on the backward movement of the breech-bolt and
then the distributing drum is rotated to bring a fresh cartridge into position. On
the breech being again closed the empty case is ejected by an ejecting finger on the
breech-bolt thus carrying out operation No. 6.
The four operations Nos. 2, 4, 5 and 6 are thus carried out by the rectilinear
movements of the breech-box and breech-bolt. The other two operations' are
effected by the rotary movement of the distributing drum, which' is effected by the
torsional reaction of a spring coiled around the axle upon which the drum is
mounted. This axle is moved to twist the spring by a fork on the front part of the
breech-box, acting upon helicoidal surfaces on the axle, the said axle turning in
one direction during the recoil and in the opposite direction during the advance of
the breech-box. One end of the torsion spring is fixed to the drum and the other
to a ring round the axle, the said ring having ratchet teeth which engage in corre-
sponding ratchet teeth on a collar fixed to the axle, the two sets of ratchet teeth
being held in contact by the longitudinal pressure of the spring. The ring carries
a pin which moves in a slot in the drum, and which determines the length of the
movement of the spring in turning the drum.
At the rear end of the distributing drum are grooves, one at each interval
between the wings, into which grooves the push finger of the breech-box enters
Buccessively to keep the drum from turning while the breech-bolt is between the
wings.
As each shot is fired the fork on the breech-box during its recoil turns the
axle of the drum, and the ratchet-wheel on the axle turns the ring and puts
the spring in torsion. As soon as the push-finger of the breech-box leaves the
groove in the drum, the torsion power of the spring turns the drum the distance
allowed by the pin on the ring and a fresh cartridge is moved to the rear
of the chamber. When the breech-box again moves forward, its push-finger
enters the next groove and the fork gives a reverse movement to the axle.
As the drum is thus prevented by the rod from turning and the ring is held in the
slot, the reverse movement of the axle only turns one ratchet wheel in rotation to
the other.
11"
The cooling of the barrel is effected by the vaporization of a sufficient quantity
of water introduced at each shot fired between the barrel and au outer tube, holes
made in the rear part of the tube entering during the recoil into an annular space
to which water is supplied under pressure from a reservoir. The steam escapes near
the muzzle of the barrel.
1...
In order to give to the mechanism, by hand, the same movements given to it
during automatic firing by the recoil, and to load the machine-gun at the commence-
ment of automatic firing, I provide a hand-lever outside the frame, which hand-
lever can also be used for ensuring the complete closing of the breech-mechanism,
in case, from any cause, this should not have been done by the reversing spring.
The hand-lever is mounted on a crank-shaft which has bearings in the two sides of
the frame. The crank when in its fixed position allows the breech-box and breech-
bolt to pass freely; when, however, the hand-lever is "turned a short distance
downwards, the crank moves forwards and supports the rear end of the breech-box,
whilst by continuing the rotary movement of the hand-lever a shot is fired, the
crank receiving the shock. The further turning of the hand-lever causes the crank
to engage in ears on the rear end of the breech-box and draws them backwards until
they escape from the crank, when all the recoiling parts are free to be again pushed
forwards by the reversing spring.
.
When firing by hand, the feeding, percussion, and extraction apparatuses operate
in the same manuer as during automatic firing.

page_text: When commencing automatic firing a cartridge is introduced into the chamber,
the breech closed and the percussion spring compressed by one complete turn of
the hand-lever.
In case of an unforeseen stop in the automatic firing caused by the incomplete
introduction of a cartridge into the chamber, it is only necessary to turn the
hand-lever about one-third of a revolution and to replace it in its fixed position
to ensure that the cartridge is fully introduced and the breech completely
closed.
The hand-lever does not during automatic firing participate in any movement of
the mechanism but remains motionless in its fixed position.
I have already stated that the trigger-catch retains the striker by its notch, and
that it is released by the last upward movement of one of the locking blocks. To
ensure safety I provide a safety trigger-catch for retaining the striker by its hook.
This catch has one arm which passes through the side of the frame slightly in front
of the handle of the hand-lever when in its fixed position for automatic firing, and
is actuated by a trigger-bolt and a trigger.
When firing automatically the gunner holds up the safety trigger-catch by
pressing on the trigger in order that the hook on the striker may pass freely
under it, whereby a shot is fired every time the locking block lifts up the trigger-
catch.
When the automatic firing is to cease, the gunner ceases to press the trigger,
whereupon the safety trigger catch arrests the striker hook and prevents the
striker from firing the percussion cap of the cartridge. The breech then remains
closed and the percussiou spring compressed; as soon, however, as the gunner
again presses on the trigger the automatic firing recommences.
When firing by hand the safety-trigger-catch is raised by the turning of the
hand-lever in time to allow the striker to pass freely as soon as the locking block
lifts the trigger-catch.
The trigger-bolt acts upon the arm of the safety trigger catch by inclined planes
when the bolt is moved either forwards or backwards. When the trigger-bolt has
no work to do, it is retained in an inoperative position by a spring which pushes it
back to that position after it has been moved forwards or backwards.
During automatic firing the trigger-bolt is pushed forwards by the trigger which
is in a convenient position for the hand placed on the handle of the hand-lever.
During hand-firing the trigger-bolt is pushed backwards by a pin with inclined
planes fitted on the hand-lever. The trigger-bolt serves also for locking the hand-
lever. When the hand-lever is in its fixed position the trigger-bolt can be pushed
forwards, a pin on the trigger-bolt entering a groove on the lower part of the
hand-lever and preventing it from being turned. To effect this the trigger is lifted
part of a turn upwards and a shoulder then wedges against the handle of the
hand-lever and pushes the trigger-bolt forwards sufficiently for locking the hand-lever
though not far enough for releasing the safety trigger-catch.
Before replacing the trigger in its ordinary position the gunner cannot turn the
hand-lever, nor accidentally fire off a shot.
The several parts of the mechanism herein before described operate in the
following manner :-
At the moment of discharging a shot, during automatic firing, the recoiling
parts are thrown back by the energy given to them through the explosion of the
charge. While high pressure remains in the barrel the breech bolt remains locked
to the breech-box by the locking blocks on the lever segment which moves back
with the movable rack. During this part of the recoil the breech-box and the
breech-bolt thus move with the same velocity. By the time the pressure in the
barrel is sufficiently reduced, the movable rack is stopped in its sliding movement
and its teeth correspond with those of the fixed rack; both together then cause
the segment lever to oscillate and disengage the locking blocks, leaving the breech-
bolt free to move rearwards. The continued oscillating movement of the segment
lever causes the slotted cam to pivot, and draw with it the bolt which thus arrives

page_text: at the end of its additional movement at the same time that the recoil of the
breech-box is completed.
The fired cartridge case is extracted by the rearward movement of the breech-
bolt, to which the spring-extractor is fixed. The extraction is very powerful in
consequence of the favorable angles at which the forward side of the slotted cam
acts upon the roller of the breech-bolt. The empty case is released from the jaw
of the extractor by the turning of the distributing drum and remains in an interval
between two wings of the said drum until it is ejected. During nearly the whole
recoil of the breech-box the fork thereon turns the axle of the distributing dram
by acting upon its helicoidal surfaces and so puts the feed spring in torsion. The
force necessary for raising and moving the belt and its cartridges transversely is
thus given to the feed spring by the breech-box itself acting slowly and at favorable
angles on the axle of the drum.
Towards the end of the recoil movement of the breech-box its push finger is
withdrawn from the corresponding groove in the drum, which thus released is
turned by the torsion of the feed spring until it is stopped by the pin of the ring,
whereby the wings of the distributing drum move the belt transversely and place
a cartridge behind the chamber of the barrel and in front of the breech-bolt.
The striker is pulled back and its spring gradually compressed during nearly the
whole additional movement of the breech-bolt the slotted cam pressing on the cross
bar of the striker until the trigger-catch engaging in its notch holds the striker
with its spring compressed.
At the end of the rearward movement of the breech-bolt its remaining energy
and that of the other recoiling parts is stored by the spring stop compressed by the
slotted cam.
The reversing spring is compressed by the recoil of the breech-box during its
entire movement rearwards and it can be so regulated that its force when
compressed will suffice for reversing the movement of the recoiling parts, push
them forward until the breech is closed and performing the operations depending
upon such forward movement.
The extraction of the empty cartridge case and the compressing of the feed
spring and percussion spring having been effected during the recoil movement, the
reversing spring can evidently be comparatively weak; the operations during the
forward movement requiring but little force.
As soon as the force of recoil has been absorbed or stored, the reversing spring,
assisted at the beginning of the return movement by the spring stop, pushes the
parts forwards, and causes the segment lever to oscillate whereby the slotted cam
moves the breech-bolt forwards; the continued pivotting movement of the
segment lever then locking the breech-bolt in the breech-box by means of the
locking blocks.
The last movement of the segnent lever causes one of the locking blocks to
lift the trigger-catch and thus releases the striker which strikes the percussion cap
in the cartridge if the gunner keeps the safety trigger-catch raised by pressing on
the trigger.
The trigger-catch being lifted by the locking block inside the gun out of reach
of the gunner, the latter cannot inadvertently fire a shot, even if pressing the trigger,
until the breech is closed.
The breech-bolt pushes a loaded cartridge into the chamber of the barrel from
one of the intervals between two wings on the drum, and the ejector rod at the
same time ejects a fired cartridge-case outside the gun.
The push finger in entering one of the grooves in the distributing drum, pushes
a loaded cartridge out of its clasp in the belt, and leaves it free in the interval
between two wings.
During the forward movement of the breech-box its fork turns the axle of the
distributing drum in an opposite direction to that in which it was turned during the
recoil whereby the ratchet teeth on the shoulder of the drum axle slide over those
on the ring, against the rectilinear pressure of the feed spring.

page_text: The metallic feed belt can be rolled up on a drum or placed in a box which
follows the laying of the gun.
When the barrel becomes hot the cooling is effected during the greater part of
its movement backwards and forwards by the introduction between the barrel and
its outer tube of a quantity of water, the evaporization of which will absorb fully
the heat given to the barrel by the explosion of each charge.
When firing by hand the crank of the hand-lever shaft, by engaging with the
ears of the breech-box effects all the operations of the mechanism including the
feeding of cartridges.
When the crank escapes from the ears of the breech-box, the reversing spring
acts in the same manner as during automatic firing, the crank, by supporting the
breech-box, taking up the shock of the discharge while the hand-lever raises the
safety trigger-catch and allows the shot to be fired as soon as the trigger-catch is
released by the locking block.
Dated the 10th day of Tune 1901
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements in Automatic Machine Guns.
I, OSCAR WILLIAM BERGMAN, of Gothenberg, in the Kingdom of Sweden, 2
Lieutenant Royal Swedish Artillery, 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 machine guns, the movements of the several parts of
which are effected under the action of the recoil, means being provided whereby 2
the gun can also be fired by hand.
In the accompanying drawings,
Figure 1 is an elevation of my improved automatic machine gun; and,
Figure 2 is a sectional plan of the same :
Figure 3 is a sectional elevation of the gun, the mechanism being shewn with
the parts in the position which they occupy when the breech is open and the
recoil almost completed; and,
Figure 4 is a longitudinal vertical section shewing the parts in the position
which they occupy at the moment of firing:
Figures 5 to 10 are sections on the lines 5-5, 6-6, 7-7,8-8, 9-9 and 10-10 3
respectively of Figure 4 drawn to an enlarged scale:
Figure 11 is a plan view drawn to an enlarged scale of the metallic cartridge
feeding belt which I employ in conjunction with my gun:
Figure 12 is a section through the belt on the line 12-12, Figure 11:
Figures 13 and 14 are respectively sections on the lines 13-13 and 14-14 of 4
Figure 12:
Figure 15 is an edge view of the belt; and,
Figures 16, 17 and 18 are perspective views of details of the belt.
The mechanism is enclosed in a frame or casing a provided with grooves, in
which several of the parts slide and with bearings for the several rotating axles,
and the frame is provided with two covers a', a', one covering the feeding a paratus
and the other the rear end of the gun.
When these covers
are open all the interior parts can be examined and
dismounted, and spare parts easily introduced.
The barrel which is adapted to recoil has at its rear end a breech-box b'{
containing the breech-bolt c; the said breech-box being formed of two side
pieces, united at the front end by the solid portion & screwed on to the barrel,

page_text: and connected near the middle and the rear end by cross-pieces b, b, the said
breech-box being adapted to slide in the frame a.
The breech-bolt c reciprocates on guides c¹, c¹ between the sides of the breech-
box and has fixed to its lower side a spring extractor d which operates in the
usual manner.
In order to produce the independent motion of the breech-bolt c relatively with
the breech-box b¹ for opening and closing the breech the following arrangement is
provided. At the rear of the breech-box is a lever e (hereinafter referred to as
the segment lever) composed of two segmental cheeks e', e' connected by a bar or
pin and carrying two screw trunnion pins e, e' which enter holes in the sides of
the breech-box (as shewn most clearly in Figure 9) and serve to pivot the
segment lever to the said breech-box. The portions of the segmental cheeks
concentric with the pivot pins are provided with gear teeth e which engage with
the two rows of teeth f, f of a rack f' capable of sliding a short distance so
that during the first part of the rearward movement of the breech-box b' under
the recoil no movement shall be imparted to the segment lever e but so that
when the rearward movement of the rack fl is stopped the continued rearward
movement of the said breech-box shall cause the said lever to turn upon the
axis of the pins e³, e. In conjunction with the rack teeth f, I arrange two
other rows of teeth g, 9 on a plate g¹ fixed to the frame or casing a, with which
teeth the teeth e of the segmental cheeks el also engage when the rack fi has.
moved rearwardly as just described, whereby on the return movement of the
breech-box rotary motion will be imparted to the segment lever before the
rack fis again moved forward.
The racks can be replaced by a plate placed in the same position as the racks,
in which plate two slots are cut of suitable length. In these slots move fingers
The distance of
or projections which replace the teeth on the segment lever.
the rear ends of the slots from the fingers where the breech is fully closed
determines the part of the recoil during which the breech remains fully closed
before the pressure in the bore has been sufficiently reduced.
When the recoil causes the fingers to bear upon the rear end of the slots the
segment lever is thereby pivotted and caused to effect all its functions during the
opening movement; when the recoil is exhausted and the reversing spring forces
the breech-box towards its foremost position, the fingers, bearing upon the front
ends of the slots, cause the segment lever to pivot in the opposite direction and
thus performs all its functions during the closing movement.
The bar or pin e' connecting the two cheeks e¹, e¹ engages in a slot in a
cam (hereinafter referred to as the slotted cam) pivotted at * to move in a
vertical plane at or near the centre of the frame, and also adapted to engage by
means of its slot with a roller i on a pin at the rear end of the breech-bolt c, in
such a manner that when during the recoil of the parts the segment lever e is
moved, a movement is imparted to the said breech-bolt independently of the
breech-box 6 through the medium of the slotted cam /.
I
In order to support the breech-bolt c during the discharge of the gun the
cheeks e', e of the lever e carry two locking blocks j, j which abut behind the end
of the breech-bolt as shewn in Figure 4 when the breech is closed, thus locking
the breech and carrying the pressure of the discharge in a line with the axis of
the barrel b.
When the pine of the segment levere is in its lowest position (see Figure 3)
the two locking blocks j, j are moved out of the breech-box b¹ so that the breech-
bolt c is free to execute its additional movement for opening the breech under the
action of the slotted cam h¹.
The percussion mechanism consists of a striker k sliding in the breech-bolt c and
a percussion spring the tail of the striker being formed with a bar which is
adapted to be engaged by the slotted cam to draw back and cock the said
*striker. Behind the said bar is a notch (Figures 2, 3, 8, 9 and 10) in which a
trigger-catch engages for retaining the striker in its cocked position.
เ

page_text: C
The trigger-catch 7 is a spring-catch and is attached to one side of the breech-
holt c, as shewn in Figures 2, 9 and 10, and when engaging in the notch of the
striker it prevents the said striker from being displaced in relation to the breech-
bolt c before the latter has completely closed the breech. The said trigger-catch
is disengaged from the striker k to allow of discharging the gun by being lifted
by one of the two locking blocks j, j on the segment levere at the moment
when the latter completes the locking of the breech by means of the said locking
blocks.
In the frame underneath the breech-box is placed a spring n (hereinafter
referred to as the reversing spring) which spring stores energy during the recoil,
and after cach discharge brings the parts forward to the firing position. One
end of this spring n presses against a protruding part of the breech-box 6 and
the other against a shoulder on a rod n which serves for regulating the strength
of the spring by means of a nut n³.
A pivotted spring-stop o is placed behind the slotted cam h¹ and the latter
strikes against it at the end of the recoil, in order to store the remaining energy
of the recoiling parts which may not have been stored in the spring n, and more
especially to store the remaining energy of the breech-bolt c. As soon as the
recoil is finished, the spring-stop o gives back such energy and helps to push the
parts forward.
The supplying of the cartridges is effected by means of a feed wheel or drum p
and of a belt g, and the feeding operation and the extraction and ejection of the
empty cases may be considered as necessitating six separate steps, viz.:—
1. Transverse movement of the belt g the distance between two consecutive
cartridges :
2. Pushing a cartridge forward out of the belt:
3. Moving the cartridge to a position behind the chamber of the barrel b:
4. Inserting the cartridge into the said chamber:
5. Extracting it from the said chamber:
6. Ejecting the fired cartridge-case outside the gun.
The distributing drum or feed wheel p is placed over the forward part of the
breech-box and rotates on an axle q¹ parallel with the centre line of the barrel
in order to convey the cartridges from the point where they are pushed from the
clips of the feed belt 7 into the breech-chamber, several cartridges being carried
forward at one time. Each movement of the distributing drum p brings one of
the intervals between the wings o into line with the breech-chamber, and allows
the passage of the breech-bolt c for inserting the cartridge and for extracting the
fired cartridge-case, thus carrying out operations Nos. 4 and 5 before mentioned.
At the same time that the breech-bolt e introduces a cartridge into the breech-
chamber from between the two lower wings another cartridge is disengaged from
the belt by a push-finger 9' on the breech-box but as the movement of the said
push-finger is shorter than that of the breech-bolt the disengaged cartridge is left
free between the two uppermost wings g' of the wheel p, thus accomplishing
operation No. 2.
The empty cartridge-case is extracted by pulling it back on the backward
movement of the breech-bolt c into the space between the wings o from which it
was previously pushed and then the distributing drum is rotated to bring a fresh
cartridge into position. On the breech being again closed the empty case is ejected
by an ejecting finger q on the breech-bolt e thus carrying out operation No. 6.
The four operations Nos. 2, 4, 5 and 6 are thus carried out by the rectilinear
movements of the breech-box b¹ and breech-bolt c. The other two operations are
effected by the rotary movement of the distributing drum p which is effected by
the torsional reaction of a spring r coiled around the axle qupon which the drum p
is mounted.
C
This axle is moved to twist the spring r by a fork r¹ on the front part of the
breech-box b, acting upon helicoidal surfaces on the axle g', the said axle turning in
one direction during the recoil and in the opposite direction during the advance of

page_text: the breech-box. One end of the torsion spring is fixed to the drum and the
other to a ring round the axle q', the said ring having ratchet teeth which
engage in corresponding ratchet teeth on a collar fixed to the axle g', the two
sets of ratchet teeth being held in contact by the longitudinal pressure of the
spring. The ring carries a pin or projection which moves in a slot in the
drum and which determines the length of the movement of the spring in
turning the said drum. At the rear end of the distributing drum p are grooves
one at each interval between the wings 9, into which grooves the push-finger q* of
the breech-box enters successively to keep the drum p from turning while the
breech-bolt c is between the wings q'.
As each shot is fired the fork on the breech-box 6' during its recoil turns the
axle of the drum p, and the ratchet wheel on the said axle turns the ring +³
and puts the spring in torsion. As soon as the push-finger q leaves the groove
in the drum p the torsional power of the spring turns the said drum the distance
allowed by the pin on the ring and a fresh cartridge is moved to the rear of
the breech chamber. When the breech-box again moves forward, its push-
finger g³ enters the next groover and the fork r gives a reverse movement to the
axle q As the drum is thus prevented by the finger q* from turning and the
ring is held in the slot by the pin the reverse movement of the axle q' only
turns the ratchet wheel in relation to the ratchet ring.
The cartridge belt 7, Figures 11 to 18, consists of a number of elastic clips &
fixed to a metal band or belt s¹, the rear part of each clip firmly holding the
cartridge, but allowing of its being pushed forwards by the projecting finger q on
the breech-box to disengage it from the clip. At one end of the clip is a stop s³
which prevents the cartridge from moving backwards. When desired the clips
can be prolonged forwards so as to protect and guide the bullet.
The clips are fixed to the flexible metal belt s¹ by covere st of a form corre-
sponding with that of the clips, openings & being formed in the metal belt s¹ between
the clips &, s, with which openings the wings g of the distributing drum p engage
to move the belt transversely.
In some cases I vary the form of the belt by making the clip and the cover in
one piece of elastic metal, and instead of fixing such combined clip and cover to
a band I join each to the next one by a link, open in the middle for admitting the
wing of the distributing drum.
In order to make the belt as flexible as possible in all directions the parts of
the band which join the clasps or clips should be at or near the level of the axial
centres of the cartridges.
The cooling of the barrel is effected by the evaporation of a sufficient quantity
of water introduced at each shot fired between the barrel and an outer tube t,
holes t¹ made in the rear part of the tube being uncovered by the barrel during
the recoil so as to open communication into an annular space to which water is
supplied under pressure from a reservoir. The steam escapes near the muzzle of
the barrel.
In some cases I surround the barrel by cold water contained in a water-jacket
in sufficient quantity under ordinary firing to cool the barrel without evaporating.
In order to give to the mechanism by hand the same movements given to it
during automatic firing by the recoil, and to load the machine-gun at the com-
mencement of automatic firing, I provide a hand-lever u outside the frame a,
which hand-lever can also be used for ensuring the complete closing of the breech-
mechanism, in case, from any cause, this should not have been done by the
reversing spring n. The hand-lever u is mounted on a crank-shaft u' which has
bearings in the two sides of the frame a, the crank u' when in its fixed position
allowing the breech-box 6' and breech-bolt c to pass freely; when, however, the
hand-lever u is turned a short distance downwards, the crank u moves forwards
aud supports the rear end of the breech-box 6' whilst by continuing the rotary.
movement of the hand-lever u a shot is fired, the crank u receiving the shock.
The further turning of the hand-lever u causes the crank u' to engage with ears **
B

page_text: +
on the rear end of the breech-box 6' and draws them backwards until they escape
from the crank u', when all the recoiling parts are free to be again pushed forwards
by the reversing spring n; or in case the spring should not act the crank u³,
during the continuation of the rotary motion, engages the breech-box b¹ at b
(Figures 3 and 4) and pushes it home thus doing the same work as the spring.
When firing by hand, the feeding, percussion, and extracting mechanisms operate
in the same manner as during automatic firing."
When commencing automatic firing a cartridge is introduced into the breech
chamber, the breech closed and the percussion spring compressed by one turn of
the hand lever.
In case of an unforeseen stop in the automatic firing caused by the incomplete
introduction of a cartridge into the chamber, it is only necessary to turn the hand-
lever u about one third of a revolution and to replace it in its fixed position to
ensure that the cartridge is fully introduced and the breech completely closed.
The hand-lever does not during automatic firing participate in any movement of
the mechanism, but remains in its fixed position.
I have already stated that the trigger-catch retains the striker k by its
notch and that it is released by the last upward movement of one of the locking
blocks To ensure safety I provide a safety trigger-catch for retaining the
striker by engaging behind a hook or lug ¹ formed thereon. This catch has an
arm
which passes through the side of the frame a slightly in front of the handle
of the hand-lever when in its fixed position for automatic firing, and is actuated
by a trigger-bolt v³ and trigger of.
by
When firing automatically the gunner holds up the safety trigger-catch
pressing against the trigger in order that the hook on the striker may pass
freely under it, whereby a shot is fired every time the locking block; lifts up
the trigger-catch 1.
When the automatic firing is to cease, the gunner ceases to press the trigger of
whereupon the safety trigger-catch engages with the striker hook v and
prevents the striker k from firing the percussion cap of the cartridge. The breech
then remains closed and the percussion spring compressed; as soon, however,
as the gunner again presses on the trigger the automatic firing recommences..
When firing by hand the safety trigger-catch is raised by the turning of the
hand-lever in time to allow the striker k to pass freely as soon as the locking
block lifts the trigger-catch 1.
The trigger-bolt acts upon the arm of the safety trigger-catch by inclined
planes vo, when the said bolt is moved either forwards or backwards. When the
trigger-bolt has no work to do, it is retained in an inoperative position by a
spring which pushes it back to that position after it has been moved forwards
'or backwards.
During automatic firing the trigger-bolt is pushed forwards by the
trigger which is in a convenient position for the hand placed on the handle
of the hand-lever. During hand-firing the trigger-bolt is pushed backwards by
a pin or projection on the lever u engaging with an inclined plane & fitted on
the said bolt. The trigger-bolt serves also for locking the hand-lever u.
When the hand-lever u is in its fixed position, the trigger bolt can he
pushed forwards, a pin ör projection on the trigger-bolt entering a groove..
on the inner side of the hand-lever and preventing it from being turned. To
effect this the trigger is turned partly upwards and a shoulder thereon then
wedges against the handle of the band-lever u and pushes the trigger-bolt
forwards sufficiently for locking the hand-lever u though not far enough for
releasing the safety trigger-catch v.
Before replacing the trigger
o
in its ordinary position the gunner cannot turn
the hand-lever u, nor accidentally fire off a shot.
The several parts of the mechanism bereinbefore described operate in the
following manner
At the moment of discharging å shot diiring aŭtomatic firing the recoiling

page_text: are thrown-back by the energy given to them through the explosion of the charge.
While high pressure remains in the barrel b, the breech-bolt c remains locked to
the breech-box b¹ by the locking blocks j, j on the segment levere which
moves back.
During this part of the recoil the breech-box b' and the breech-bolt c thus move
with the same velocity. By the time the pressure in the barrel b is sufficiently
reduced, the movable rack f' is stopped in its sliding movement and its teeth
coincide with the fixed rack teeth g. Or the fingers hereinbefore described on the
segment lever e bear against the ends of the slots with which they engage; 'both
together then cause the said segment lever to oscillate and disengage the locking
blocks j, from the breech-bolt cleaving the latter free to move rearwards. The
continued oscillating movement of the segment lever e causes the slotted cam /¹ to
turn upon its pivot, and draw with it the bolt c which thus arrives at the end of
its additional movement at the same time that the recoil of the breech-box 6' is
completed.
The fired cartridge-case is extracted by the rearward movement of the breech-
bolt c to which the spring-extractor d is fixed. The extraction is very powerful in
consequence of the favourable angles at which the forward side of the slotted
cam acts upon the roller i of the breech-bolt c. The empty case is released from
the jaw of the extractor d by the turning of the distributing drum p and remains
in an interval between two wings g of the said drum until it is ejected.
During nearly the whole recoil of the breech-box b' the fork thereon turns the
axle 2' of the distributing drum by acting upon its helicoidal surfaces and so puts
the feed spring in torsion. The force necessary for raising and moving the belt
and its cartridges transversely is thus given to the feed-spring by the breech-
box 61 itself acting slowly and at favourable angles on the axle q' of the drum. p.
Towards the end of the recoil movement of the breech-box 6' its push-finger q
is withdrawn from the corresponding groove in the drum p which, thus released,
is turned by the torsion of the feed-spring until it is stopped by the pin of
the ring, whereby the wings of the distributing drum p move the belt
transversely and place a cartridge behind the chamber of the barrel 6 and in front
of the breech-bolt c.
The striker k is pulled back and its spring ¹ gradually compressed during
nearly the whole additional movement of the breech-bolt c, the slotted cam A¹
pressing on the cross-bar of the striker until the trigger-catch engaging in its
notch holds the said striker with its spring compressed.
At the end of the rearward movement of the breech-bolt c its remaining energy
and that of the other recoiling parts is stored by the spring-stop o compressed by
the slotted cam h¹.
The reversing spring n is compressed by the recoil of the breech-box 6' during
its entire movement rearwards and it can be so regulated that its force when
compressed will suffice for reversing the movement of the recoiling parts, pushing
them forward until the breech is closed, and performing the operations depending
upon such forward movement.
The extraction of the empty cartridge case and the compression of the reversing
spring n and percussion spring k' having been effected during the recoil move-
nient, the said reversing spring can evidently be comparatively weak; the
operations during the forward movement requiring but little force.
As soon as the force of recoil has been absorbed or stored, the reversing spring n
assisted at the beginning of the return movement by the spring-stop o, pushes the
parts forwards, and causes the segment lever e to oscillate, whereby the slotted
cam h¹ moves the breech-bolt c forwards; the continued pivotting movement of the
segment levere then locking the breech-bolt c in the breech-box by means of
the locking blocks j, j.
The last part of the movement of the segment levere causes one of the locking
blocks to lift the trigger-catch and thus release the striker k which strikes the

page_text: .
percussion cap in the cartridge if the gunner keeps the safety trigger-catch raised
by pressing against the trigger o.
The trigger-catch being lifted by the locking block j inside the gun out of
reach of the gunner, the latter cannot inadvertently fire a shot, even if pressing the
trigger until the breech is closed.
The breech-bolt c pushes a loaded cartridge into the chamber of the barrel b from
one of the intervals between two wings q on the drum, and the ejector q* at the
same time ejects a fired cartridge-case outside the gun.
p
The push-finger in entering one of the grooves in the distributing drum
pushes a loaded cartridge out of its clip in the belt g and leaves it free in the
interval between two wings g³.
During the forward movement of the breech-box b¹ its fork turns the axle gl
of the distributing drum p in an opposite direction to that in which it was turned
during the recoil, whereby the ratchet teeth on the collar of the said drum axle
slide over those on the ring against the rectilinear pressure of the feed-
spring r.
The metallic feed-belt q can be rolled up on a drum or placed in a box which
follows the laying of the gun.
When firing by hand the crank u of the hand-lever shaft u', by engaging with
the ears of the breech-box 6' (the reversing spring n acts in the same manner as
during automatic firing) supports the said breech-box, taking up the shock of the
discharge, while the hand-lever u raises the safety trigger-catch r and allows the
shot to be fired as soon as the trigger-catch is released by the locking block j.
Having thus fully described my invention I desire, before formulating my claims,
to state clearly that the following inventions are, each of them separately or in
combination with one another, public property, in consequence of the Patents which
may have at some period of time protected them having expired, viz. :-
(a) The automatic cycle of guns, in which the opening or closing of the breech,
the successive introduction of cartridges into the chamber, and the firing of such
cartridges, are effected directly or indirectly by the explosion of the charge of
powder in order to fire automatically and rapidly a consecutive number of rounds
from such guns.
The automatic cycle was patented in 1854 and was afterwards the subject wholly
or in part of a number of other Patents now expired which have indicated different
moles of carrying it into practical effect.
In those inventions the force produced by the explosion of the charge has been
utilized, either by means of the recoil of one or more parts of the weapon itself or
by storing the force by means of springs, counterweights, hydraulic, pneumatic
or hydro-pneumatic appliances, for accomplishing different operations of the
automatic cycle.
(6) The employment of movable frames or breech-boxes with movements
depending upon that of the gun in relation to other fixed frames.
(c) The use of a bolt or breech-block set in motion directly or indirectly by the
explosion of the powder charge, obtaining thereby a movement additional to that
of the breech or of the gun itself.
(d) The introduction of cog gear for determining the relative movements of
different parts of the breech-mechanism of a machine-gun.
(e) The utilization of a fixed point on a frame which does not participate in the
recoil, for accomplishing not only the opening and closing of the breech of a recoiling
gun, but also for fulfilling other functions such as firing off the cartridges, etc.
(f) The employment of a crauk-shaft for allowing the breech-mechanism to
support the pressure or blow created by the explosion of the powder charge.
(9) Means for delaying the opening of the breech until the pressure produced in
the bore of the gun by the explosion of the powder charge has been sufficiently
reduced.
(h) The use of a flexible belt for feeding a machine-gun with cartridges as well

page_text: as the use of a revolving drum provided with wings for moving the cartridges
into position in the rear of the chamber of the barrel.
(i) The use of water for cooling a gun.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, declare that what I
claim is :-
-
1. In an automatic machine-gun the combination of the breech-box, the breech-
bolt, the segment lever, the slotted cam, and the reversing spring for accomplishing
the opening and closing of the breech, substantially as described.
2. In an automatic machine-gun the segment lever and its rack or plate arranged
and operating substantially as described.
3. In an automatic machine-gun the segment lever mounted in the frame and
provided with locking blocks bearing upon the breech-bolt for supporting the blow
of the discharge by locking the breech-bolt to the breech-box, substantially as
described.
4. In an automatic machine-gun the sliding rack which during the first part of
the recoil moves back owing to its engagement with the teeth of the segment lever
and afterwards acts in conjunction with the fixed rack for oscillating the segment
lever, substantially as described.
5. In an automatic machine-gun the breech-bolt provided with a roller acted
upon by a slotted cam for giving to the breech-bolt a longer stroke than that of the
breech-box, substantially as described.
.:
6. In an automatic machine-gun the slotted cam oscillating on an axle fixed to
the frame, the slot in which cam is engaged by the segment lever for setting it in
motion, and which cam by means of its slot also acts upon a roller in the breech-
bolt for giving to the latter a prolonged stroke, substantially as described.
7. In an automatic machine-gun the combination of the slotted cam, the breech-
bolt, the striker and the percussion spring, the latter being compressed by the
slotted cam during the recoil of the breech-box, substantially as described.
8. In an automatic machine-gun the feeding apparatus in which a spring is
placed in torsion during the recoil and while a distributing drum is held in a fixed
position by a push-finger on the breech-box, which spring as soon as the push-finger
is withdrawn from the distributing drum turns such drum sufficiently for moving a
cartridge to its position in front of the breech-bolt, substantially as described.
9. In an automatic machine-gun the transformation of the rectilinear movement
of the breech-box into the rotary movement for placing the spring of the distributing
drum in torsion, substantially as described.
10. In an automatic machine-gun the ring fixed to the spring in the distributing
drum and the ratchet teeth on the axle of the drum engaging in corresponding teeth
on the ring for the purposes described.
11. In an automatic machine-gun the combination with the ring referred to in the
preceding claiming clause of a pin moving in a slot on the distributing drum for
regulating the movement of the said drum, substantially as described.
12. In an automatic machine-gun the use in combination with the feeding apparatus
of two fingers, one, the push-finger, for releasing the cartridge from the belt being
fixed to the breech-box, and the other, the ejecting finger, fixed to the breech-bolt..
for ejecting the fired cartridge, substantially as described.
13. In an automatic machine-gun the utilization of the push-finger which releases
the cartridge from the belt, for the purpose of holding the distributing drum in a
fixed position while its spring is being placed in torsion, substantially as described.
14. The flexible metallic feed belt constructed substantially as described for use
in an automatic machine-gun.
15. In an automatic machine gun the use of a hand-lever, mounted on the frame,
which hand-lever remains stationary during the automatic firing and which is
connected with a crank-shaft acting upon ears on the breech-box to effect the recoil
movement of the latter and compress the reversing spring, thus giving the required

page_text: movements to all the parts of the breech-mechanism and the feeding apparatus when
the machine-gun is fired by hand, substantially as described.
16. In an automatic machine-gun the utilization of the crank-shaft on the hand-
lever and of ears on the breech-box, not only for giving a rearward movement to
the breech-box and allowing it to escape from the crank-shaft as soon as such.
rearward movement is completed, but also for ensuring the complete closing of the
breech and for supporting the breech-box during the explosion of the charge when
firing by hand, substantially as described.
17. In an automatic machine-gun the trigger-catch acted upon by one of the
locking blocks of the segment lever, which locking block raises the trigger-catch as
soon as the segment lever is in the position in which the breech-bolt is completely
locked to the breech-box, substantially as described.
18. In an automatic machine-gun the provision of means for effecting by hand
all the movements of the gun including the feeding of the cartridges by a belt,
substantially as described.
19. In an automatic machine-gun a safety trigger-catch arranged and operating
substantially as described.
20. In an automatic machine-gun a trigger-bolt and a trigger arranged and
operating in relation with one another as well as in connection with the hand-lever,
substantially as described.
21. The improved automatic machine-gun consisting of the parts constructed
and combined substantially as hereinbefore described and illustrated in the
accompanying drawings and operating as, and for the purpose, set forth.
Dated this 13th day of April 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.