Improvements in and relating to Quick-firing and other Breech- loading Ordnance.
Year: 1893

page_text: Date of Application, 5th Aug., 1893
Complete Specification Left, 3rd May, 1894-Accepted, 30th June, 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Quick-firing and other Breech-
loading Ordnance.
I, CHARLES GUSTAV MELLSTROM, of Victoria Mansions, 32 Victoria Street,
Westminster, Civil Engineer do hereby declare the nature of this invention to be
as follows:-
--
My invention relates chiefly to quick-firing guns but parts of it are applicable to
other breech-loading guns for increasing the strength and durability of the breech
and for facilitating the action of their breech-mechanism. The main object of the
said invention is to construct a quick-firing gun, of that class wherein a screw-
breech-block is employed, in such a manner that the breech requires no lateral
aperture for the insertion and withdrawal of the breech-block, which is carried on
a vertical hinge or pivot at the side of the breech and can be inserted into and
withdrawn from the gun by a simple movement about its hinge or pivot.
The said breech-block has projecting screw-threaded portions fitted to engage
with similarly screw-threaded segmental portions in the gun so that by turning
the said block about its axis in the gun the screw-threaded portions of the block
will engage with or be disengaged from those in the gun, in the usual manner.
The said block is supported in a carrier which is hinged or pivotted at the side of
the breech-end of the gun. I attach the block to the carrier by its head or outer
end in such a manner that the block is supported and held firmly by the carrier as
it is moved into and out of the gun.
My said invention consists partly in adapting the breech for the reception of a
novel form of breech-block and in the peculiar construction and method of actuating
the said block.
Heretofore segmental-screw breech-blocks have been usually made cylindrical
or parallel-sided along their screw-threaded portions. They have also, though not
commonly, been made conical so that the small end of the block projects inward
and closes the breech. But according to my present invention I employ a breech-
block, tapered along its screw-threaded portions in such a manner that its largest
diameter is at its inner end, and it is constructed and arranged as hereinafter
described.
As above stated, the breech-block is inserted and withdrawn by moving it about
the aforesaid hinge, that is to say it does not have to slide end wise through the
carrier. But I do not have to curtail its length; it may be of the ordinary length
of a screw breech-block, but as the breech has no lateral opening throughout its
entire circumference it is obvious that the chamber for the breech block, and the
block, must be so formed that the block can move in the arc of a circle about the
axis of the hinge and that in so moving it will clear the sides of the said chamber,
and yet, when home and locked in the chamber will properly close the breech.
For this purpose the said chamber has its sides so shaped in longitudinal section as
to just clear the circular arcs through which the sides of the block move in entering
and leaving the said chamber.
I prefer that the hinge or pivot of the carrier should be arranged about midway
between the outer and inner ends of the screw-threaded chamber.
I may use any suitable form of screw-threads, V-shaped square, or otherwise.
In some instances I prefer to form the block and chamber with a series of steps
increasing in diameter towards the large or inner end of the block.

page_text: Instead of using a taper-sided breech-block, such as that above described, I
sometimes use a cylindrical segmental-screw block or plug.
For turning the breech block about its axis to lock and unlock it and for moving
it with the carrier about its hinge I provide the outer end of the block with a
circular toothed segment preferably arranged below its axis and I gear with this
toothed segment a pinion on a vertical shaft which is supported in suitable bearings
on the hinged carrier and which has attached to or formed with it the operating-
lever of the breech mechanism. The said pinion has teeth on only a portion of
its periphery, that is to say, it has only as many teeth as are necessary to keep in
gear with the segment on the block to turn the latter a sufficient distance about its axis
to move the screw-threads thereon into and out of gear with those of the gun. In
the turning of the block about its own longitudinal axis it moves endwise through
a short distance by the action of the screw threads and therefore the teeth on the
said block are put more deeply into gear with those of the pinion. To prevent
inconvenience from this movement I make the teeth of the latter excentric to the
shaft so that as the block moves backward they recede therefrom. If I make the
segments of the block and chamber with simple interlocking ribs and grooves
instead of with screw-threads this excentricity of the toothed pinion will not be
necessary. The said pinion moreover has on it a shoulder or projection arranged
to act as a stop to the rotation of the pinion when the same has been turned
through about a quarter of a revolution by means of the operating lever. This
stop then comes in contact with the back surface of the carrier so that the continued
movement of the said lever then tends to turn the carrier about its axis in the
proper direction to withdraw the breech-block from the gun and move the same
clear away from the breech-aperture. Thus it will be seen that in a gun provided
with my improvements the breech block in opening the breech has only two
movements, riz. :-rotation on its own axis and a circular movement about the
vertical hinge or pivot, which movements are effected by one continuous movement
of the lever in one direction, the closing of the breech being effected by similar
movements in the reverse order and direction.
The breech-block carries a firing-pin which extends through a central hole
therein. I prefer to use a firing-pin which is semi-annular or trough shaped in
transverse section except at its rear and forward ends. In the trough or curved
portion of the said pin place a spiral spring which bears against the forward
end of the pin and is so arranged that it will be compressed when the latter is
drawn back to cock the gun.
The cocking is effected by the rotation of the block about its axis in unlocking it.
For this purpose I form or fix on the said block a helical or cam surface which
engages with a lug or projection on the rear end of the firing pin. The said firing
pin is so controlled that it is kept from rotating with the block, and the helical
surface is so arranged that as the block rotates its action on the lug of the firing-
pin forces the same backward into engagement with the trigger-mechanism. For
guiding, and preventing the rotation of, the firing pin in the block I insert into the
head of the latter a plate formed to cover the aperture through which the said pin
is inserted into the block; this plate has projecting forward from its inner side
two lugs having between them a space into which projects a fin or finger on the
lower side of the firing pin. This plate is held in place by the pivot pin or bolt
of the operating lever and when the said bolt is removed can be taken out of the
block to afford access to the firing pin or permit the insertion or removal of
the same.
The firing pin has at its rear end a rod projecting through the plate which rod
is formed at its outer end into a hook. By means of this hooked rod the firing pin
can he cocked in case of a missfire without moving the breech block.
The extractor is a lever pivoted near the carrier hinge with an arm or pair of
arms extending into the proper position to engage with the rim of a cartridge
in the gun. A short arm or projection on this lever is arranged to be struck by a
shoulder on the carrier as the latter is turned upon its hinge to open the breech.

page_text: The trigger-mechanism comprises a retaining catch or sear on an arm which is
pirotted to the carrier in the proper position to engage with a projection or
shoulder on the firing pin when the same has been drawn back by the action of the
helical or cam surface on the breech block. The outer end of the said pivotted
arm is bent or cranked so that it projects into a position wherein it will be actuated
by an arm fixed on the end of a pin or bolt which projects through the side of the
breech chamber and the outer end of which is provided with a trigger. A spring
is arranged in combination with the pivotted arm to act thereon to press the catch
or sear into engagement with the firing pin.
In combination with the trigger-mechanism I arrange a safety device consisting
of a small spring lever provided at one end with a stud or bolt that, until the parts
are ready for firing, passes through the carrier into a hole in the aforesaid pivotted
arm and holds the sear so that it cannot release the firing pin. But when the
operating lever is properly home it compresses the spring of the said spring-lever
and raises the bolt out of the hole in the pivotted arm so that the latter can be
actuated by the trigger to release the firing pin and fire the gun.
In breech-mechanism wherein a screw-breech-block is supported with a capability
of rotation about its axis, in a carrier which withdraws the block from the gun,
the said block while moving in and out of the gun has its screw-threads totally
disconnected from those of the gun; therefore it is necessary to provide means for
holding the block immovably in the carrier while it is out of the breech-chamber
so that when the block has been pushed home again in the said chamber its screw-
threads will be in exactly the same position relatively to those in the chamber as
they were when the said block had been turned on its axis to unlock it but before
the carrier commences to turn about its hinge. For this purpose I employ a
spring-pin or catch which is so arranged in the carrier that when the breech block
has been turned on its axis to unlock it from the gun a recess in the said block
comes opposite the said spring catch so that the latter engages therewith and holds
the block so that it cannot be displaced by turning on its axis while moving with
the carrier about the hinge or pivot of the latter. I prefer to place over the
aperture in which the said spring-catch is placed, a cover-plate screwed into the
carrier. The said catch has a hollow or tubular stem wherein I place the spiral
spring which abuts against the said cover plate so as to press the catch into
engagement with the recess in the block.
To avoid accidents from hangfire I provide the gun with a device which will
prevent the premature opening of the breech if the cartridge in the gun does not
explode when the trigger is pulled. For this purpose I prefer to employ the safety
appliance described in the Specification of my former Patent dated December 3rd
1891 and numbered 21123. This appliance consists essentially of a pendulum
arranged in combination with the breech mechanism to prevent the movement
thereof until the gun has completed its recoil after a discharge; then the said
pendulum by continuing to move in the direction of the recoil after the recoil
action has ceased will release the lever of the breech-mechanism so that the breech
can be opened; but if the cartridge is not exploded the said pendulum remains
inoperative.
I now combine this device with my improved breech-mechanism as follows, that
is to say, I attach the pendulum in any convenient position to the gun or suitable
part of the mounting, and I combine therewith a latch fixed on the said lever in
such a position that the hook-shaped extremity of an arm on the pendulum will
engage with the said latch before the gun is fired, the said arm being pressed into
engagement with the latch by a suitable spring; the said pendulum acts, as above
described, to release the lever if the cartridge explodes properly, but not otherwise.
And in combination with this device I arrange an elastic plate having a stud or
projection which is arranged to engage with a shoulder on the hooked arm of the
pendulum and hold the same out of engagement with the latch until the lever has
been pulled back. On the side of the elastic plate are double inclines arranged in
combination with similar inclines on the latch of the lever, so that in moving the

page_text: said lever the said inclines will act to push the projection of the plate out of
engagement with the pendulum to allow the latter to resume its normal position.
I prefer that this mechanism should be enclosed by a casing at the side of the gun.
This improved device may be employed with either a recoil or a non-recoil
mounting.
Data: 1
A 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in and relating to Quick-firing and other Breech-
loading Ordnance.
I, CHARLES GUSTAV MELLSTROM, of Victoria Mansions, 32 Victoria Street,
Westminster, Civil Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates chiefly to quick-firing guns, but parts of it are applicable
to other breech-loading guns for increasing the strength and durability of the
breech and for facilitating the action of the breech mechanism. The main object
of the said invention is to construct a quick firing gun, of that class wherein a screw
breech-block is employed, in such a manner that the breech requires no lateral
aperture for the insertion and withdrawal of the breech-block which is carried on a
vertical hinge or pivot at the side of the breech and can be inserted into and
withdrawn from the gun by a simple movement about its hinge or pivot.
The said invention consists partly in adapting the breech for the reception of a
novel form of breech-block, and in the peculiar construction of the said block and
method of actuating the same.
The said breech-block is of the class known as segmental screw-blocks i.e. it has
projecting screw-threaded portions fitted to engage with similarly screw-threaded
segmental portions in the gun so that by turning the said block about its axis in the
gun the screw-threaded portions of the block will engage with or be disengaged
from those in the gun, in the usual manner. The said block is supported in a
carrier and thereby hinged or pivoted at the side of the breech-end of the gun.
I attach the block to the carrier by its head or outer end in such a manner
that the block is supported and held firmly by the carrier as it is moved into and
out of the gun.
Heretofore segmental screw breech-blocks have been usually made cylindrical or
parallel sided along their screw-threaded portions. They have also, though not
commonly, been made conical so that the small end of the block projects inward
and closes the breech. But according to the present invention I employ a breech-
block which is reversely tapered or coned that is to say it is tapered along its screw
threaded portions in such a manner that its largest diameter is at its inner end; it
is constructed and operated as hereinafter described.
The accompanying drawings shew the breech of a gun provided with the present
improvements.
Figure 1 is an elevation of one side of the breech.
Figure 2 is an elevation of the other side of the said breech.
Figure 3 is a rear elevation of the same.
Figure 4 is a horizontal longitudinal central section through the breech and
breech-block shewing the breech closed.
Figure 4 is a rear view of a locking mechanism hereinafter described.
Figure 5 is a section on the line x, x Figure 3 shewing the breech open.
Figure 6 is a central section,
Figure 7 is a side view and

page_text: .
Figure 8 is a rear view of the breech block alone, drawn to a larger scale.
Figure 9 is a section on the line 2¹¹ Figure 8.
Figure 10 is a rear view of half the carrier bracket drawn to a larger scale.
Figure 11 is a section on the line y, y Figure 10.
Figure 12 is a section on the line y¹ y¹ Figure 10.
The remaining figures shew details of the mechanism, drawn to a larger scale.
Like letters indicate corresponding parts throughout the drawings.
A is the breech portion of the gun; A' is the screw-threaded chamber therein;
B is the breech-block; C is the carrier; D is the lever for operating the breech-
block; C' is the hinge or pivot of the carrier; E is the extractor.
As above stated, the breech-block B is inserted and withdrawn by moving it
about the hinge, at C', that is to say, it does not have to slide end wise through the
carrier. Nevertheless I do not have to curtail its length, it may be of the
ordinary length of a screw breech-block, but as the breech has no lateral opening
throughout its entire circumference the chamber A¹ and the block B must be so
formed that the block can move freely through the chamber in the arc of a circle
about the axis of the hinge C in opening and closing the breech, and yet, when home
and locked in the chamber it must securely and tightly close the breech. For this
purpose the said chamber has its sides shaped in longitudinal section as shewn in
Figures 4 and 5, that is to say, the two sides of the chamber are arcs of circles
whose centre is the axis of the pivot C' and which have such radii as will allow
sufficient clearance for the sides of the block B to pass without touching them in
entering and leaving the said chamber.
I prefer that the hinge or pivot C¹ of the carrier C be arranged about midway
between the outer and inner ends of the screw-threaded chamber, as shewn. It
will be observed that the carrier and the part B* of the block that engages
therewith are screw-threaded, and have the screw threads continuous all around
the same.
It it obvious that a reversely coned or taper breech-block which is moved to lock
and unlock the same by the action of its peripheral screw-thread on a screw-
thread in the breech of the gun must not have a screw-thread consisting of a spiral
with a continuously and uniformly increasing diameter from the small to the large
end of the cone, for if so formed such convolution or turn of the screw-thread, in
moving forward to close the breech would pass from a part of the spiral groove in
the gun in which it has a firm bearing to another part of the said gun of larger
diameter and would therefore cease to be efficiently supported in the breech at the
time when the most efficient support is required.
I therefore form the spiral or screw thread as follows: that is to
say, com-
mencing with the smaller end of the cone and taking a line from one to the other
end along the exterior of the same I form the first turn of the screw thread so that
it has the same diameter and a uniform pitch or longitudinal advance entirely
around the block then continue the spiral from the termination of this turn or
convolution of the thread on the said line so as to form the next turn or convolution
with a larger diameter but in the same manuer i.e. without increase of diameter.
That is to say, the spiral or screw thread of the cone consists of a series of turns or
convolutions each of which is concentric with the axis of the cone entirely around
the same and merges into a convolution of larger diameter towards the forward end
of the cone with a uniform or continuous inclination or pitch from one to the other
end of the same. I complete the said cone by planing off or otherwise removing
portions of the screw threads, and then the said reversely coned breech block
has two or more portions of its periphery consisting of a series of spiral segments
of a uniform pitch suitable for ensuring the necessary end wise movement of the
block but each complete turn having all of its segments of equal radius. There-
fore in turning the breech-block to cause its screw threads to engage with those in
the gun the threads in the different segments of the block will turn and advance in
the grooves in the gun so as to force the block into close contact with the breech
while maintaining a firm bearing and support therein.

page_text: Instead of making each single complete turn of the screw thread of a different
-diameter from the preceding turn I may make the block in steps, that is to say,
with two or more complete turns of the thread of one diameter and next to them
two or more turns of a larger diameter and so on throughout the length of the cone.
It will be obvious that the screw threads in the gun must correspond with those of
-the block.
I may use screw threads which are V shaped as shewn, or which are square or
-otherwise suitably shaped in cross section.
Instead of using a taper-sided breech-block such as that above described I some-
times use a cylindrical segmental-screw block or plug.
For turning the breech-block about its axis to lock and unlock it, and for moving
it with the carrier about its hinge I provide the outer end of the block with a
circular toothed segment or series of teeth at B' preferably arranged below its axis
and I gear with this toothed segment a segmental pinion F on a vertical shaft F¹
which is supported in suitable bearings C on the hinged carrier C and which has
-attached to or formed with it the operating lever D of the breech-mechanism. The
said pinion has only as many teeth as are necessary to keep in gear with the
segment B on the block B to turn the latter a sufficient distance about its axis to
move the screw threads thereon into and out of gear with those of the gun. In the
turning of the block about its own longitudinal axis it moves end wise through a
short distance by reason of the pitch of the screw-threads and therefore the teeth
on the said block approach the axis about which the pinion F turns. To prevent
inconvenience from this movement I make the teeth of the pinion excentric to the
shaft F as shewn in Figure 13 which is a plan of the lever and pinion detached and
in which 1 is the centre of the shaft and 2 the centre of the segment. Therefore
as the block B moves backward the teeth of the pinion recede therefrom, and
vice versa when the block moves forward the teeth of the pinion approach the same.
If I make the segments of the block and chamber with parallel fillets instead of
with screw-threads this excentricity of the toothed pinion will not be necessary.
"The said lever moreover has a shoulder at D' arranged to act as a stop to the
rotation of the pinion when the same has been turned through about a quarter of a
revolution by means of the operating lever D as shewn in Figure 5. This stop
then comes in contact with the back surface of the carrier C and can move no
further relatively to the carrier, therefore from this position the continued move-
ment of the lever D tends to turn the carrier C about its axis C¹ in the proper
direction to withdraw the breech-block from the gun and move the same clear away
from the breech-aperture. Thus it will be seen that in a gun provided with my
improvements the breech-block in opening the breech has only two movements viz.:
rotation on its own axis and a circular movement about the vertical hinge or pivot,
which movements are effected by one continuous movement of the operating lever
in one direction, the closing of the breech being effected by similar movements of
'the reverse order and direction.
The breech-block B carries a firing-pin G which is shewn detached in side and
-end elevation in Figures 15 and 16. This pin extends through a central hole in
the block. I prefer to use a firing-pin which is semi-annular or trough shaped in
transverse section except at its rear and forward ends. In the trough or curved
portion of the said pin I place a spiral spring G' which bears against the forward
end of the pin at G and is so arranged that it will be compressed when the latter
is drawn.back to cock the gun.
In the ordinary working of the gun the cocking is effected by the rotation of the
block B about its axis in unlocking or releasing the block from the gun. For this
purpose I provide the said block with a helical or cam surface B' most clearly
shewn in Figure 6 which is a section of the block B detached. Said surface
engages with a lug or projection G³ Figures 15 and 16 on the rear end of the firing
pin G. The said firing pin is so controlled that it is kept from rotating with the
block during the cocking action, and the helical surface of the block is so arranged
that as the block rotates its action on the lug G³ of the firing-pin forces the same

page_text: backward into engagement with the trigger mechanism. For guiding, and.
preventing the rotation of the firing-pin in the block I insert into the head of the-
Iatter a piece H formed to cover the aperture through which the said pin is-
inserted into the block. This piece H is passed over, and held in place by, the
pivot pin or bolt F' of the operating lever and when the said bolt is removed can
be taken out of the block to afford access to the firing-pin or permit the insertion
or removal of the same. Said piece H forms the rear bearing for the spring G'.
The firing pin bas at its rear end a hook Go projecting through the carrier and
through a slot H' in the said piece H and the firing pin is thereby prevented from
turning about its axis while being cocked. By means of the said hook the firing
pin can be cocked in case of a missfire without moving the breech block.
The extractor E is a lever pivoted near the carrier hinge at E' and has an arm.
or pair of arms E* of the ordinary kind extending into the proper position to engage
with the rim of a cartridge in the gun, as shewn. The tail end E of the extractor
is arranged to be struck by a shoulder C³ on the carrier as the latter is turned upon.
its hinge C¹ to open the breech.
The trigger mechanism comprises various parts which are shewn detached in
Figures 17, 18, 19 and 20. A retaining catch or sear I is formed or fixed on an
arm I' the stem 1° of which is pivoted to the carrier at I' Figure 10 in the proper-
position to engage with a projection or shoulder G' of the firing-pin G when the
same has been drawn back by the action of the helical or cam surface B' of the
breech-block. The outer end of the said pivoted arm I' is bent or cranked as-
shewn at I so that it projects into a position wherein it will be actuated by an
arm K fixed on the end of a pin or bolt K' which projects through the side of the
breech chamber and the outer end of which is provided with a trigger K². A
spring 1 is arranged in combination with the pivoted arm I' to act thereon to press-
the catch or sear I into engagement with the firing-pin.
In combination with the trigger-mechanism I may sometimes employ a safety
device consisting of a small spring-controlled lever R Figure 21 pivoted at R' and'
provided at one end with a projection R' that until the parts are ready for firing
passes through the carrier into a hole or recess I in the aforesaid pivoted arm
and holds the sear so that it cannot release the firing pin. But when the operating
lever is properly home it compresses the spring R of the said lever R and raises
the bolt out of the hole or recess I* in the pivoted arm I' so that the latter can be
actuated by the trigger to release the firing pin and fire the gun.
In breech-mechanism wherein a screw breech block is supported with a capability
of rotation about its axis in a carrier which withdraws the block from the gun. the
said block while moving in and out of the gun has its screw-threads totally
disconnected from those of the gun; therefore it is necessary to provide means for-
holding the block immovably in the carrier while it is out of the breech chamber so.
that when the block has been pushed home again in the said chamber its screw-
threads will be in exactly the same position relatively to those in the chamber as
they were when the said block had been turned on its axis to unlock it but before.
the carrier had commenced to turn about its hinge. For this purpose I employ a.
spring-pin or catch L Figures 3 and 5, shewn detached in end view and longitudinal
section in Figures 22 and 23. This catch is so arranged in the carrier C that when
the breech-block B has been turned on its axis to unlock it from the gun a.
recess B see Figures 8 and 9 in the said block comes opposite the said spring
catch so that the latter engages therewith and holds the block B so that it cannot
be displaced by turning about its axis while moving with the carrier C about the
hinge or pivot C¹ of the latter. I prefer to place over the aperture in which the
said spring-catch is placed, a cover-plate screwed into the carrier. The spring
catch L has a hollow or tubular stem L' from which projects a toe L'. Inside the
hollow stem I place the spiral spring which abuts against the said cover plate so as.
to press the catch into engagement with the recess in the block. Until the block B.
has been turned so that its screw threads are released from those in the gun, the-

page_text: toe L' lies in a groove C' in the carrier, but when the block is ready to move out
of the breech the toe is opposite the recess B' in the screw thread in the block and
by the action of the spring is pushed in the said recess as soon as the carrier
commences to swing round on its hinge and the block is thereby kept from turning
about its axis. In closing the breech, when the carrier comes in contact with the
end of the gun, the projecting catch L Figure 5 is forced back and thereby its toe
is disengaged from the said recess in the block and pushed back into the groove in
the carrier, the block is then free to turn in the carrier.
To avoid accidents from hang-fire I provide the gun with a device which will
prevent the premature opening of the breech if the cartridge in the gun does not
explode when the trigger is pulled. For this purpose prefer to employ a
pendulum so arranged in combination with the breech-mechanism as to prevent the
movement thereof until the gun has completed its recoil after a discharge; if the
charge has been fired, the said pendulum under the influence of the energy of
the recoil in which it has participated continues to move in the direction of the
recoil after the recoil action has ceased and will by this continued movement release
the lever of the breech-mechanism so that the breech can be opened; but if the
charge has not been fired the said pendulum remains inoperative. The pendulum
does not act by reason of its inertia at the beginning of the recoil but by its
momentum at the termination of the recoil.
I combine this device with my improved breech-mechanism as follows, that is to
say, I suspend the pendulum M by its arm on a piu or stud M' fixed in any con-
venient position to the gun or suitable moving part of the mounting. I provide
the said pendulum with a hook-shaped arm M. A latch D is formed or fixed
on the operating lever D in such a position that the hook-shaped arm M' on
the pendulum will engage with the said latch and remain in engagement there-
with before and until the gun is fired, the said arm M' being pressed into
engagement with the latch by a suitable spring M. When the gun is fired, the
said pendulum moving with the gun in its recoil acquires sufficient momentum to
act very efficiently as above described to release the operating lever so that the
breech can be opened. But if the charge hangs fire and consequently there is no
recoil, the pendulum remains inoperative and the said lever is not released. In
combination with this device I arrange an elastic plate N having a stud or
projection N' which is arranged to engage with a recess M* in the hooked arm of
the pendulum and hold the same out of engagement with the latch D³ until the
lever D has been pulled back to open the breech. On the side of the elastic
plate N is an incline N' arranged in combination with a similar incline d on the
latch of the lever D, so that in turning the lever about its pivot F' when closing
the breech the said inclines will act to push the projection of the plate out of
engagement with the pendulum to allow the latter to resume its normal position.
I prefer that this mechanism should be enclosed by a casing O at the side of the
gun as shewn in Figure 4.
This improved pendulum device may be employed with either a recoil or non-
recoil mounting. The effect of a pendulum acting with the energy which it has
acquired in the recoil movement of the gun even though such movement should be
very slight (as in the case of a non-recoil mounting) will always be sufficient to
release the lever and in this respect my improved device is advantageously
distinguishable from those in which a pendulum is arranged to act by its inertia at
the commencement of the recoil movement.
It might happen in some instances when the gun is laid at a high elevation that
the operating lever, through the concussion caused by the discharge, will escape
from the control of the aforesaid safety device. I therefore provide an additional
retaining device as follows, that is to say, I form a recess Do, Figures 13 and 14
in the said lever and place therein a spring latch P formed with an arm P¹ which
projects through the said lever and lies at the side of the handle D*. The nose P
of the latch is arranged to enter a socket or recess P' in the carrier and thereby

page_text: hold the lever D so that it cannot move away from the same. But in grasping the
handle to open the breech the hand also grasps the arm P' which is thereby pressed
inward and releases the latch; the lever D will then be free to move outward as
required.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. A reversely conical or taper screw threaded or filletted breech-block forming
part of a gun which has a similarly formed chamber in which the said block is
fitted, and in which it operates, for the purpose specified.
2. The peculiar formation of the screw threads of the breech-block as, and for
the purpose, specified.
3. The combination of the said breech-block with the hinged carrier, and the
connection of the two parts by the continuous screw threads as, and for the purpose,
specified.
4. The screw threaded breech-block chamber constructed as above described,
and the combination of the breech block and carrier therewith, so that the block
can enter and leave the gun by a simple movement about the hinge of the carrier,
and by a continuous movement of the operating lever in one direction.
5. The combination, with the said block and carrier, of the operating lever and
the toothed gearing having provision for the end wise movement of the block, and
with the extractor, substantially as, and for the purpose, specified.
6. The firing pin carried by the breech-block and actuated thereby, and arranged
in combination with the sear and trigger, substantially as, and for the purpose,
specified.
7. The combination, with the trigger mechanism, of the safety device which
holds the sear in engagement with the firing pin until the parts are in the firing
position, substantially as, and for the purpose, specified.
8. The safety device having a pendulum which locks the operating lever, until
the gun has recoiled, and then releases the lever at the termination of the recoil by
virtue of the momentum it has acquired during the recoil.
9. The combination with the said pendulum, substantially as described, of the
elastic plate for holding the pendulum out of engagement with the latch of the
lever until the latter has been pulled back.
10. A gun provided with breech mechanism substantially such as that herein
described, for the purposes specified.
Dated: 33
1001
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.