Improved Safety Breech-lock for Machine-guns and other Guns.
Year: 1895

page_text: Date of Application, 12th Sept., 1895-Accepted, 26th Oct., 1895
Improved Safety Breech-lock for Machine-guns and other Guns.
A communication from abroad by Charles Meyer, of 1 Rue Larrey, Paris, in
the Republic of France, Accountant.
I ALFRED GEORGE BROOKES of 55 and 56 Chancery Lane, in the County of
London, Chartered Patent Agent, 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 :—
The object of my invention is to provide a means for locking automatically the
breech-block of a quick firing, machine or other gun, in such a manner that the
breech cannot be opened before the discharge of the piece except by a definite and
conscious action on the part of the gunner; to provide a means for automatically
unlocking the breech immediately on the discharge of the piece and to provide a
means for throwing the safety lock out of action when it is desired to manipulate
the gun without firing, as at drill.
In the
All guns are liable to what is technically known as "hang fires" and this is
particularly the case when "brown" and "smokeless" powders are employed, as a
defect in the priming may cause a very appreciable time to elapse between pulling
the lanyard or the fall of the firing pin and the discharge of the piece.
beat of action, when the gun is being fired at its maximum rapidity, the gunner
operating the breech mechanism works almost automatically, and may (as has
occurred) open the breech after the primer has been struck, but before the
discharge of the piece, thus causing a disastrous accident.
In accordance with one
My invention is designed to prevent such accidents.
arrangement of my safety lock, my invention consists essentially of a bolt mounted
on a gun held normally in engagement with the breech mechanism to lock it by a
spring or other suitable yielding device and automatically throw it out of engage-
ment therewith on the recoil of the gun after firing.
In the accompanying drawings which illustrate this first arrangement,
Fig. 1 is a view partly in cross section of my safety lock applied to the breech
mechanism of the well known Hotchkiss quick firing gun, in which the safety lock
is shown in the locked position at the moment that the hammer has struck the
primer of the cartridge, but before the discharge of the gun.
Fig. 2 is a view partly in cross section of the same after the firing of the gun,
with the safety lock retracted and the breech-block partially withdrawn.
Fig. 3 is an end view of the device for throwing the safety lock out of action.
Fig. 4 is a view partly in cross section on the line 4-4 of Fig. 2 showing the
forward end of the breech block.
A Figs. 1 to 4, is the breech of the gun and B is the breech-block. C is a box
or case containing the safety lock device. In this instance, the box C is screw
threaded at its open end by which it is secured in its seat C₁ in the breech-block
but it may also consist of a chamber recessed in the breech-block itself. B is a
passage through the breech-block forming a prolongation of the case and centering
with a similar passage A' drilled through the breech A, when the breech-block is
in the closed position and the gun is ready for discharge. D is the safety bolt
or piston having a limited longitudinal play in the case C in the line of the recoil
of the gun. When the bolt D is thrust toward the breech of the gun, its
extremity D' projects through the passage B' beyond the rear face of the breech-

page_text: block, ready to engage in the corresponding chamber A' in the breech and when
the bolt is retracted, it lies flush with the rear face of the breech-block. A coiled
spring D2 located within the case C and abutting between a collar d on the bolt D
and the end of the case, holds the bolt normally in position to engage with the
aperture A of the breech. E is a sear pivoted to the case C and thrown into
engagement through a slot c in the case with the groove d' of the bolt D when the
spring D is compressed against the bolt. A spring e lodged between the tail e¹
of the sear and the case C, holds the sear normally in position to engage with the
bolt and lock it when the latter is retracted out of the way of the breech. Fis
the shaft or axis of the firing hammer, on which is mounted a cam F' in position
to engage with the tail e of the sear E and to withdraw the latter from engage-
ment with the bolt on the cocking of the hammer after the discharge.
The operation of this first arrangement is as follows: When the gun is in
the position shown in Fig. 1, at the moment that the hammer has struck the primer
of the cartridge, but before the discharge of the piece, the extremity D' of the
safety bolt which is thrust out by the stress of the spring D² engages in the
chamber A of the breech. It is now impossible to open the breech, as all move-
ment of the breech-block is prevented by the bolt D. On the discharge, the gun
recoils, but the bolt by its inertia does not partake of this motion, but the
spring D2 is compressed against it until the sear E actuated by its spring e rises
and engaging in the groove in the bolt D prevents the latter from resuming its
original position. The breech of the gun may now be opened. As the breech
block descends, the hammer is cocked and the revolution of the shaft F brings the
cam F in position to encounter the tail e¹ of the sear E, raising it and releasing
the bolt D, which resumes its normal position under the stress of the spring D².
On closing the breech, the bevelled extremity D¹ of the bolt encounters the
inclined plane a on the breech A and the bolt is forced back, but not sufficiently
to engage the sear E. When the breech is completely closed, the extremity D¹
of the bolt is thrust into the passage A' in the breech by spring D² and the breech
is again locked.
To open the breech without firing the gun or to render the safety lock
inoperative, I provide a lever G which is keyed to a bolt G located in the
chamber A. of the breech. A spiral groove on the bolt engages with the guide
screw g controlling the throw of the bolt. When the lever G is given a half turn
to the left to the position marked " Danger," the bolt G moves forward
completely, closing the chamber A', thus preventing the entrance of the safety
bolt D and the breech may now be opened or closed at will.
It is evident that the aperture closing the device mounted in the breech may be
employed with any safety lock, automatic or otherwise, in which the chamber or
recess engages with a bolt or other device on the safety lock.
I will now consider another arrangement of my safety lock. In a machine gun,
where, as in the well known Hotchkiss revolving cannon, the rotating of the
harrels, the loading and firing mechanism and the extraction and discharge of the
cartridges are actuated by the rotation of a single shaft through its various
connections, the gunner turns the crank continuously, and a "hang fire" cartridge
may explode during extraction, or even upon the ground, with equally grave
results.
Heretofore, the safety lock, as far as known to me, has been so located in the
gun breech that it engages directly with the gun body or vice versa, or it has been
so located in the gun breech as to engage with a recess in the breech-block crank, or
vice versa. In both instances, it has the great disadvantage of occupying a position
difficult of access to the gunner, and of having a construction which renders it
unavailable where the adjacent parts of the breech and breech-block are concealed
or under cover, or otherwise inaccessible. In the second instance, the recessing of
the breech-block crank, either to engage with or to contain the safety lock is a
source of great weakness to a part of the gun mechanism which, when in use, is
subject to a severe strain, and for this reason is practically unavailable.

page_text: bolt, substantially as described and shown in Figs. 5, 6, 7, 8 & 9 of the
accompanying drawings.
9. The combination with a safety lock for a gun, said lock having a bolt adapted
to be actuated by the recoil of the gun, of a locking cam located in the path of
said bolt and a device to throw said cam into and out of engagement with said
bolt, substantially as described and shown in Figs. 5, 6, 7, 8 & 9 of the accompanying
drawings.
Dated the 19th day of Sentember 1895.
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, Agents for the Applicant.

page_text: The object of this second arrangement is to remedy these objections by providing
a means for locking automatically an exterior part of the breech-block operating
mechanism of a quick firing machine or other gun, in such a manner that the
mechanism cannot be operated and the breech opened before the discharge of the
piece, except by a definite and conscious action on the part of the gunner; by
providing means for automatically unlocking or releasing the breech operating
mechanism immediately upon the discharge of the piece and to provide means for
throwing the safety lock out of action when it is desired to manipulate the gun
without firing as at drill.
My object is to further provide a safety locking device which can be equally
well applied to the breech operating mechanism, the firing mechanism or the barrel
revolving mechanism of a gun either one or all, to maintain the breech closed until
after firing, and whether such operating mechanism be concealed in the breech-
block as in the case of the Hotchkiss revolving cannon, or in any other inaccessible
location, where such mechanism is actuated by an exterior projecting, rotatable or
movable part.
This second arrangement consists in placing a spring safety lock actuated by
inertia in the path of a laterally projecting exterior rotating rocking or moving
part of the firing, breech actuating or barrel revolving mechanism of the gun, and
in providing it with a scar so located in respect to such part, that said safety lock
shall be automatically caused to lock said rotating, rocking or moving part, by the
movement of said part itself into a position in which the gun breech is closed, until
said safety lock is withdrawn by the firing of the gun, whereupon the above
operation is again repeated. It further consists in a particular locking cam device,
by which the safety lock can be thrown out of action at will.
Figure 5 is a view of the safety lock applied to the bevel pinion on the crank
shaft of the well known Hotchkiss revolving cannon. Figs. 6, 7 & 8 are detail
views of the safety lock shown in Fig. 5 with the front plate removed, and Fig. 9
is a horizontal longitudinal section through the same.
A, Fig. 5, is the breech piece, B the main shaft, B' the pinion of the mechanism,
and C is the crank for manipulating the shaft and pinion, all of a well known
construction. D is the box or case attached to the frame of the gun. E is the
safety bolt. E' is its extremity projecting through the aperture D¹ in the case.
F is a stop mounted upon the pinion B' in position to engage with the bolt when
the latter is thrust forward and the pinion is revolved. E2 is the coiled spring
located in the recess 2 in the rear of the bolt and abutting against the end of the
casc. G is the spring sear secured to the case D and engaging through the slot d
with the notch e of the bolt, when the latter is thrust back and the spring
compressed. is the tail of the sear projecting into the path of the stop F on the
pinion B.
In this instance, the operation of the safety lock is as follows: When the gun is
in the position shown in Fig. 5, the firing pin has struck the primer of the cartridge.
In order to reach the point at which the barrels begin to revolve opening the
breech, the pinion B' and with it the stop I is turned through an angle of 90 degrees,
but if the discharge of the gun has not taken place, the projecting extremity E' of
the safety bolt encounters the stop F on the pinion before the full movement is
completed and prevents the opening of the breech. If the discharge has taken
place, the gun recoils and the inertia of the bolt overcomes the resistance of the
spring E, compresses it and allows the sear G to spring up and maintain the bolt
withdrawn in the position shown in Fig. 6. The pinion B₁ can now complete its
revolution and the stop F striking the tail of the sear G forces it down,
releasing the bolt E which resumes its original position under the stress of the
spring E. In the event of a hang fire, the bolt E may be withdrawn by means
of the handle and the stop F allowed to pass. To throw the safety lock
completely out of action, as when operating the gun at drill, 1 mount the lever H
on a shaft passing through the face of the box and projecting into a recessed
chamber in the bolt E. On the shaft is the eccentric cam, which beara

page_text: against the end wall of the chamber e when the lever is turned to the danger
position, holding the bolt sufficiently withdrawn to permit of the stop F, but not
sufficiently to permit the sear to engage..
I do not limit myself to the combination of the safety lock as constructed by
me with the pinion B and the stop F, as it is evident that any laterally pro-
jecting exterior part rotating or moving in the path of the safety lock will be
within the scope of my invention.
Having thus described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I
claim is:
1. The combination, with the breech of a breech-loading gun having the
chamber A and a bolt in the breech-block adapted to engage in said chamber,
of the lever G, its spirally grooved shaft G' located in said chamber A' and guide
screw mounted in the breech and engaging in said groove, substantially as
described and shown in Figs. 1, 2, 3 & 4 of the accompanying drawings.
2. The combination, with the breech of a breech loading gun, of the breech A
having the chamber A', the lever G, its spirally grooved shaft G' located in said
chamber and the guide screw g' mounted in the breech and engaging in said groove,
of the breech-block B having a safety lock engaging in said chamber when the
same is open, and rendered inoperative when the same is closed, substantially as
described and shown in Figs. 1, 2, 3 & 4 of the accompanying drawings.
3. The combination, with the breech of a breech-loading gun having the
chamber A, and a bolt in the breech-block which registers with said chamber when
the breech is closed, of a rod or shaft located in said chamber and longitudinally
adjustable therein, whereby said bolt is permitted to engage or prevented from
engaging said chamber at will, and a device mounted on the breech for adjusting
said rod or shaft, substantially described and shown in Figs. 1, 2, 3 & 4 of the
accompanying drawings.
4. In a breech-loading gun, the combination, with the gun breech having a
rccess, and means to open and close said recess, of the breech-block having a bolt
which registers with said recess when the breech is closed, substantially as described
and shown in Figs. 1, 2, 3 & 4 of the accompanying drawings.
5. In a breech loading gun, the main shaft B, the pinion B1 mounted on said
shaft, the stop F on said pinion, and a safety lock having a bolt held normally in
the path of the stop by a spring, and withdrawn from under the stop by means of
the recoil of the gun, substantially as described and shown in Fig. 5 of the
accompanying drawings.
6. In a breech loading gun, the main shaft B, the pinion B' mounted on the
shaft, the stop F on said pinion and a safety lock having a holt held normally in
the path of the stop by a spring, and withdrawn from under the stop by means of
the recoil of the gun, and a spring sear for locking said bolt when withdrawn,
having an arm projecting into the path of said stop, substantially as described and
shown in Figs. 5, 6, 7, 8 & 9 of the accompanying drawings.
7. The combination of a case D, the bolt E located therein and having the
recessed chamber e, the spring E2 located in the recess e in the rear of the bolt,
the spring sear G, the lever H on the exterior of the case, its shaft I passing
through the face of the case and the eccentric cam i mounted on the shaft and
bearing against the walls of the recess e in the bolt E, substantially as described
and shown in Figs. 5, 6, 7, 8 & 9 of the accompanying drawings.
8. In a breech loading revolving gun having the pinion B', the combination,
with the stop Fon the pinion, of the case D secured to the gun, the bolt E located
therein having the recesses e² and e and normally projecting into the path of the
stop F, the spring E2 located in the recess e in the rear of the bolt, the spring
sear G having the tail g projecting into the path of the stop F, the lever H on the
exterior of the case, its shaft L passing through the face of the case, the eccentric
cam mounted on the shaft within the recess e¹ of the bolt, and the handle e³ of the