Improvements in Automatic Guns.
Year: 1894

page_text: Date of Application, 20th June, 1894
Complete Specification Left, 19 h Mar., 1895-Accepted, 24th May, 1995
PROVISIONAL SPECIFICATION.
Improvements in Automatic Guns.
I, MASSUJI YAMANOUCHI, Lieutenant in the Imperial Japanese Navy, of
76 Gower Street in the County of Middlesex, do hereby declare the nature of this
invention to be as follows:-
The gun is formed with parallel sides on its exterior. Around the centre of the
gun is screwed a ring to form a piston-the portion of the gun in rear of this ring
may be of larger diameter than the portion in front of it. The rear portion of the
gun is surrounded by a fixed outer cylindrical casing-the piston ring or head fits
this cylinder. The ends of the cylindrical casing are formed with glands and
packing the packing at the front end embracing the gun in front of the piston
ring and the other packing embracing the rear portion of the gen. Around the
rear portion of the gun and within the cylindrical casing is a coiled spring bearing
at its ends against the rear end of the casing and against the piston and serving to
run the gun forward after recoil. Through the piston two or more small passages
are formed each fitted with a ball valve which allows liquid to pass during recoil
but not to return when the gun runs forward.
The gland at the rear end of the outer cylindrical casing has screwed on to it a
rearward extension of the casing the breech end of the gun and the breech
mechanism lies within this extension of the casing and slides along it when the gun
recoils.
The breech block is formed to lock into the breech end of the gun with divided
screw threads. Outside the gun the rear end of the screw breech block has a
flange around it which fits within the rearward extension of the casing-the rear
end of the screw breech block also passes through the end of an arm which extends
upwards through a slot cut longitudinally along the top of the rearward extension
of the cylindrical casing a nut screwing on to the rear end of the screw breech
block holds the arm up to the flange but leaves the breech block free to turn.
A coiled torsion spring connects the arm and breech block together.
As the arm passes through the slot in the outer casing it cannot turn but can
slide backwards or forwards whilst the screw breech block can both slide and turn.
A projection on the flange of the breech block enters a cam groove in the extension
of the casing. The groove follows a course in the form of a right angled triangle.
The base of this triangle which is foremost is at right angles to the bore-the side
which is at right angles to the base extends rearwards parallel with the bore and
the third side inclines from one to the other-that side which is parallel with the
bore is also prolonged rearwards beyond the apex of the triangle.
When the breech block is in its locked position the projection extending from it
is at the point of the groove where the base joins the inclined side-when the
recoil takes place the projection travels along the inclined side and thereby gives a
partial turn to the breech block and unlocks it, at the same time putting torsion on
the spring tending to turn the block back into its locked position. At the end of
the recoil the projection arrives at the apex of the triangle and when the breech
block is subsequently moved to the rear to open the breech the projection travels
along the rearward extension of that side of the triangle which is parallel with the
bore.
When the breech block is again run forward to close the gun the projection
is made to travel along this side of the triangle and when it arrives at the point
where this side meets the base the spring having up to this time been kept in

page_text: torsion can now turn the screw breech block and lock it within the breech of
the gun.
The moving of the breech block backwards and forwards is effected in the
following manner.
On the top of the outer cylindrical case and parallel with it is a smaller
cylinder a piston fitting this smaller cylinder has a rod extending rearwards from
it through the rear end of the cylinder and its end is secured to the upper end of
the arm above mentioned. A coiled spring surrounds the rod and bears against
the rear end of the small cylinder and against the back of the piston and serves to
run forward the screw breech block into its locked position.
Communication is provided between the front end of the small cylinder and the
front end of the cylindrical casing through two holes one slightly in rear of the
other. If thought necessary a slide may be fitted to the rear hole serving as a
valve to open and close it.
A firing pin is passed through the breech block along its central longitudinal
oxis this firing pin is thrown forward by a coiled spring which surrounds it in the
ordinary manner.
On the rear end of the firing pin are two projections one to he acted on by the
ecking mechanism the other by the trigger. The cocking mechanism consists of
a lever pivotted to lugs projecting from the rear face of the arm above mentioned
one arm of the lever bears against one of the projections on the rear end of the
firing pin the other enters a groove in the fixed outer cylindrical casing-the
bottom of this groove is inclined and when the gun recoils the arm which enters
the groove being brought against this incline is turned and the other arm bearing
against the projection on the rear end of the firing pin forecs the firing pin
backwards into its cocked position.
The upper consists of two parts held together and in place by a hinge bolt.
Between the two parts is a torsion spring. On the trigger are two projections the
spring tends to bring one projection behind the second projection on the firing pin
when the pin is cocked and keep the pin from being thrown forward whilst the
other projection is acted on by a stud on the flange of the screw breech block just
at the last locking movement of the screw-the trigger is thereby turned and the
firing pin allowed to be thrown forward to fire the gun.
On the left side of the rearward extension of the outer case is a hopper to hold
the cartridges.
An opening is cut on the left side of the case to allow the cartridges to fall from
the hopper into the case while a shorter opening is cut on the right hand side to
allow the empty cartridge cases to be thrown out. A slight ledge is made to
project up from the lower part of the outer case to keep ench full cartridge when
it has dropped from the hopper into the case in a central position.
A flat spring extractor is fitted to the breech screw to withdraw the case from
the gun. A projection from the arm hereinbefore mentioned prevents more than
one cartridge passing into the case each time the gun recoils. Hand means will be
provided on the outside and about the rear end of the case to control the firing of
the gun so that the gun can be fired or prevented from firing at any time. A cap
is screwed on to the end of the rearward extension of the care to close up the
mechanism.
The action of the gun in firing is as follows. When the gun is loaded and about
to be fired the cylindrical case is full of liquid, but the small cylinder is empty.
The gun recoils about 3 inches and in doing so unlocks the breech screw by means
of the cam groove already described. During recoil the liquid is driven past the
small ball valves to the front of the piston. The foremost of the two small holes
between the small cylinder and outer case is open whilst the other is closed. The
breech screw and arm compled to it are of course carried to the rear with the gun.
When the gun runs forward through the action of the spring which surrounds it
the liquid to the front of the piston not being able to return to the rear of the
piston is forced through the open hole into the small cylinder and forces back the

page_text: piston of this cylinder until the gun is fully forward thus the breech screw and
horn instead of coming forward with the gun are carried further to the rear.
When the screw is being unlocked the cartridge is loosened, due to the pitch of
the screw, thus when the gun runs forward, and the breech screw is carried to the
rear, the empty cartridge is easily extracted and ejected. During the first
movement of recoil the firing pin drawn back into its cocked position as above
explained.
When the screw breech block is forced to the rear a projection from the arm
which is coupled to it allows a full cartridge to drop from the hopper into the case
and if perchance the empty case has not been thrown out the weight of the full
case will force it over the ledge. Before another case has time to drop through
the opening, the screw breech block is travelling forward to the gun and the
projection from the arm intervenes and prevents a second cartridge from descending.
The rear part of this projection is always over the mouth of the opening until the
screw breech block again recoils. When the screw breech block is run forward by
the action of the spring which surrounds the piston rod of the small cylinder it
carries the full cartridge with it into the gun, and the screw breech block is locked
and the gun fired as already described. Also when the screw breech block runs
forward the piston of the small cylinder forces the liquid from this cylinder back
into the cylindrical case through the rearmost of the two holes which is now opened
through the slide valve being carried forward with the gun, and the foremost hole
is now closed.
JL:
O
τ
1000
M. YAMANOUCHI.
Improvements in Automatic Guns.
I, MASSUJI YAMANOUCHI, Lieutenant in the Imperial Japanese Navy, of
76 Gower Street, in the County of Middlesex, 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:―
Figure of the drawings hereunto annexed is a longitudinal section of an
automatic gun constructed according to my invention.
Figure 2 is a cross section on the line 1, 1 Figure 1, and Figure 3 a section on
the line 2, 2 Figure 2.
Figure 4 is a diagram view of the cam groove used for unlocking the breech block
as the gun recoils.
The gun is formed with parallel sides on its exterior. Around the centre of the
gun is screwed a ring A to form a piston-the portion of the gun in rear of this
ring may be of larger diameter than the portion in front of it. The rear portion
of the gun is surrounded by a fixed outer cylindrical casing C-the piston ring or
head A fits this cylinder. The ends of the cylindrical casing are formed with
glands and packing D and E-the packing at the front end embracing the gun in
front of the piston ring A and the other packing embracing the rear portion of the
gun. Around the rear portion of the gun and within the cylindrical casing is
a coiled spring F bearing at its ends against the rear end of the casing Cand
against the piston A and serving to run the gun forward after recoil. Through
the piston two or more small passages are formed and fitted with a ball valve B
which allows liquid to pass during recoil but not to return when the gun runs
forward.
The gland at the rear end of the outer cylindrical casing has screwed on to it
a rearward extension G of the casing, the breech end of the gun and the breech
niechanism lies within this extension of the casing and slides along it when the gun
recoils.

page_text: The breech block H is formed to lock into the breech end of the gun with divided
screw threads. Outside the gun the rear end of the screw breech block has a
flange Haround it which fits within the rearward extension G of the casing-the
rear end 11 of the screw breech block 11 also passes through the end of an arm H*
which extends upwards through a slot cut longitudinally along the top of the
rearward extension G of the cylindrical casing, a nut H screwing on to the rear
end of the screw breech block holds the arm 112 up to the flange H' but leaves
the breech block free to turn. A coiled torsion spring H³ connects the arm and
breech block together.
As the arm H passes through the slot in the extension G of the outer casing it
cannot turn but can slide backwards or forwards whilst the screw breech block H
can both slide and turn. A projection on the flange 11 of the breech block 11
enters a cam groove in the extension G of the casing. The groove follows a course
in the form of a right angled triangle see Figure 4. The base of this triangle
which is foremost is at tight angles to the bore-the side which is at right angles
to the base extends rearwards parallel with the bore and the third side inclines from
one to the other--that side which is parallel with the bore is also prolonged rearwards
beyond the apex of the triangle.
When the breech block is in its locked position the projection extending from it
is at the point of the groove where the base joins the inclined side-when the
recoil takes place the projection travels along the inclined side to K and thereby
gives a partial turn to the breech block and unlocks it, at the same time putting
torsion on the spring tending to turn the block back into its locked position.
At the end of the r coil the projection arrives at the apex of the triangle and when
the breech block is subsequently moved to the rear to open the bretch the
projection travels in the direction L along the rearward extension of that side
the triangle which is parallel with the bure. When the breech block is again
run forward to close the gun the projection is made to travel along this side of the
triangle from L to M and when it arrives at the point M where this side meets tho
Las the spring H having up to this time been kept in tersion can now turn
the screw breech block H and lock it within the breech of the gun.
The moving of the breech block backwards and forwants is effected in the
following manner.
On the top of the outer cylindrical case and parallel with it is a smaller
linder (^' a piston (^” fitting this smaller cylinder has a rud (* extending rearwards
from it through the rear end of the cylinder and its end is secured by at C³ to the
upper end of the arm H7 above mentioned. A coiled spring C surrounds the rod
mud bears against the rear end of the small cylinder (and against the back of the
piston and serves to run forward the screw breech block into its locked
position.
Communication is provided between the front end of the small cylinder and
the front end of the cylindrical casing (through two holes, one C slightly in rear
of the other C If thought necessary a slide valve C dovetailed into the
inside of the cylinder C may be fitted to the rear bole C serving as a valve to
open and close it.
A firing pin N is passed through the breech block II along its central longitudinal
axis this firing pin is thrown forward by a coiled spring № which surrounds it in
the ordinary manier.
On the rear end of the firing pin are two projections № and N° see Figure 2
one to be acted on by the cocking mechanism the other by the trigger. The cocking
mechanism consists of n lever pivotted to lugs P projecting from the rear face
of the arm above mentioned, one arm of the lever bears against the projection N
on the rear end of the firing pin the other enters a groove in the fixed outer
cylindrical casing G-the bottom of this groove is inclined and when the gun recoils
the arm which enters the groove being brought against this incline is turned and the
other arm bearing against the projection No on the rear end of the firing pin forces
the firing pin backwards into its cocked position.

page_text: The trigger consists of a body R in two parts held together and in place by a
Between the
hinge bolt. One part is fixed, the other movable around the bolt.
two parts is a torsion spring. On the movable part or trigger proper are two
projections RR, the spring tends to turn the movable part so as to bring one
projection R behind the projection N on the firing pin when the pin is corked and
to keep the pin from being thrown forward whilst the other projection R' is
acted on by a stud H on the flange H' of the screw breech block H just at the
last locking movement of the screw-the trigger is thereby turned and the firing pin
allowed to be thrown forward to fire the gun.
On the left side of the rearward extension of the outer case is a hopper S to hold
the cartridges.
An opening S is cut on the left side of the case G to allow the cartridges to
fall from the hopper into the case while a shorter opening S is cut on the right
hand side to allow the empty cartridge cases to be thrown out.
A slight
ledge G is made to project up from the lower part of the outer case G to keep
each full cartridge when it has dropped from the hopper into the case in a central
position.
A flat spring extractor is fitted to the breech screw to withdraw the case from
the gun. Projections H from the arm H hereinbefore mentioned prevents more
than one cartridge passing into the case each time the gun recoils. Hand means
will be provided on the outside and about the rear end of the ease to control the
firing of the gun so that the gun can be fired or prevented from firing at any time.
A cap G³ is screwed on to the end of the rearward extension of the case to close up
the mechanism.
The action of the gun in firing is as follows. When the gun is loaded and
about to be fired the cylindrical case C is full of liquid, but the small cylinder Cl
is empty. The gun recoils about 3 inches and in doing so unlocks the breech
screw by means of the cam groove already described at the same time putting the
spring 3 in torsion. During recoil the liquid is driven past the small ball
valves B to the front of the piston and the small hole C between the small
cylinder and outer case C is closed whilst the other C is opened by the
movement of the slide C. The breech screw and arm are of course carried
is
to the rear with the gun. When the gun runs forward through the action of
the spring which surrounds it the liquid to the front of the piston not being
able to return to the rear of the piston is forced through the open hole C7 into the
small cylinder C¹ and forces back the piston C of this cylinder until the gun
fully forward thus the breech screw and horn instead of coming forward with the
gun are carried further to the rear. When the screw breech block H is being
unlocked the cartridge is loosened, due to the pitch of the screw, thus when the
gun runs forward, and the breech screw is carried to the rear, the empty cartridge
is easily extracted and ejected. During the first movement of recoil the firing
pin is drawn back into its cocked position as above explained.
When the screw breech block is forced to the rear the projection H from the
arm H2 no longer impedes the descent of a cartridge from the hopper and now
allows a full cartridge to drop from the hopper into the case G and if perchance
the empty case has not been thrown out the weight of the full case will force it
over the ledge. Before another case has time to drop through the opening St the
screw breech block is travelling forward to the gun and the projection H from the
arm intervenes and prevents a second cartridge from descending. The rear part
of this projection then always remains over the mouth of the opening until the
screw breech block again recoils. When the screw breech block is run forward by
the action of the spring C which surrounds the piston rod C of the small
cylinder C¹ it carries the full cartridge with it into the gun, and the screw breech
block is locked and the gun fired as already described. Also when the screw
breech block runs forward the piston of the small cylinder C forces the liquid from
this cylinder back into the cylindrical case through the hole C which is now opened

page_text: through the slide valve C being carried forward with the gun, and the foremost
hole is now closed.
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
1 claim is :-
:―
1. An automatic gun in which the breech block is unlucked during recoil and
liquid caused to pass from back to front of the piston of a recoil cylinder and in
which when the gun is run forwards the liquid is caused to pass to a second
cylinder of smaller diameter and by pressing back the piston of that cylinder
to carry back the breech block away from the rear end of the gun.
2. The combination of the gun, the piston surrounding it, the cylindrical casing
within which the piston works, the coiled spring surrounding the gun and pressing
the gun forwards, passages through the piston fitted with valves which allow liquid
to pass from the rear to the front of the piston when the gun recoils but not to
pass in the opposite direction-the second cylinder of smaller diameter into the
front end of which the liquid is forced as the gun is run forward-the piston of this
second cylinder having a rod extending backwards from it-the spring for pressing
the piston forwards the breech block-the arm to which it is coupled and which
is fixed to the piston rod of the second cylinder so that when this rod is pressed
backwards as the gun runs forward the breech block is carried back along with it.
3. The passage between the cylindrical casing and the second cylinder which
is opened just as the forward movement of the gun is completed and allows the
liquid in the second cylinder to be forced back into the cylindrical casing in rear of
the piston on the gun.
4. The combination of the cocking and trigger mechanism substantially as
described.
5. The automatic gun substantially as herein before described and illustrated in
the drawings annexed.
Dated this 11th day of February 1895.
M. YAMANOUCHI.