Improvements in and relating to Breech-loading Small-arms and Machine Guns.
Year: 1890

page_text: Date of Application, 10th Jan., 1890
Complete Specification Left, 10th Nov., 1890-Accepted. 27th Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in and relating to Breech-loading Small-arms and
Machine Guns.
I, OSKAR WILLIAM BERGMAN, of Gothenburg, in the Kingdom of Sweden,
Lieutenant in the Royal Swedish Artillery, do hereby declare the nature of this
invention to be as follows:-
My invention relates to military or sporting rifles or small arms with or without
magazines, and to machine guns operated either by hand or automatically by the
force of the recoil, and it comprises the improvements hereinafter described.
My improved breech-mechanism comprises two essential parts, namely, what I
term a block and a carrier, which block and carrier are located in a chamber or
frame at the breech of the gun. The block is pivotted on a horizontal axis at the
rear part of the said frame, and the carrier is adapted to be moved horizontally
forwards and backwards in guides in the said frame by means of studs, attached to
the said carrier and entering a cam groove formed in the said block, in such a
manner that, when the block is moved or oscillated upon its pivot to open the
breech, the carrier will be drawn back. When the block is moved to close the
breech the carrier is again moved forward. The shock of the discharge is thus
received by the carrier supported by the block which by its axis carries over the
pressure to the frame. A portion of the groove with which the carrier is in
engagement when the breech is closed is made concentric with the axis upon which
the block moves, so that the said carrier is allowed to remain stationary during the
first part of the movement of the block; the other parts of the groove are so shaped
as to rapidly move the carrier backwards during the remaining part of the movement
and vice versa when the breech is to be closed.
The carrier has attached to it extractors for withdrawing the empty cartridge
shells from the barrel and a firing-pin which is made in parts passes through the
carrier. The hammer for striking the said firing-pin is placed at the rear in such
a position that, when the block is moved to open the breech, the said hammer will
be cocked, or the firing pin itself, actuated by a spring, can be cocked directly by a
stud moved by a second cam groove in the block.
Motion is advantageously imparted to the block by means of a lever, one end of
which forms a handle, or by means of a crank. The motion can also be effected by
utilizing the force of the recoil when the arm is fired. In this case the barrel and
the frame are adapted to slide in suitable guides and a pin or stud in the fixed bed
which does not recoil enters a slot adjacent to the pivot of the block in such a manner
that, when the frame moves backwards owing to the force of the recoil, the block
will be moved relatively to the stud in engagement with the slot, and so caused to
turn upon its axis.
In some cases instead of employing a block which merely oscillates upon its
axis I employ a block which completely rotates and has a continuous cam groove;
in this case one part of the cam groove is advantageously formed to withdraw the
carrier while the other serves to return it to its normal position. If desired,
however, the cam groove may be made with duplicate portions so that the carrier
will be reciprocated to and fro twice during each rotation of the block.
In applying my invention to machine guns adapted to be operated by hand I
advantageously employ a block having a complete rotary motion.
In order to fire the cartridges the trigger can be operated either by the rotation
of the said block or by hand.
When my improvements are applied to guns in which the recoil is utilized for

page_text: effecting the various operations of the arm, the barrel and frame are adapted to
slide as hereinbefore stated, and are placed in connection with a fixed bed carrying
a stud for causing the movement of the blocks. With this arrangement the force
of the recoil acts upon the breech mechanism without the employment of intermediate
crank-shafts or of other additional parts, which is not the case with other such guns.
In connection with the frame and barrel is arranged a spring which serves to
return the barrel to its normal position to close the breech, and thus to introduce
the cartridge and to perform other operations.
In a machine gun where the recoiling force actuates the breech mechanism I can
advantageously employ the rotating block having duplicate cam grooves as I am
thereby enabled to dispense with the use of springs for performing any of the
operations of the mechanism, the force of the recoil being employed for this purpose,
light springs being merely necessary for returning the barrel to its normal position.
The rotating block is in some cases made with the parts carrying the two cam
grooves in different planes so that one part of the block will work in connection
with one barrel and the other part in connection with another barrel.
I prefer to supply the cartridges by means of a belt of special construction. This
belt, which can be made either of canvas, metal or other suitable material has fixed
to it clips of steel into which the cartridges are placed. One end of each clip is
made sloping or bevelled so that when the cartridge is pushed therefrom the flange
thereof will impinge against the said bevelled surface and so force the cartridge out
of the clip, and into the mechanism.
It is to be understood that this belt is equally applicable for other guns in which
feeding belts are employed.
The belt is advantageously passed through the gun by a gear or sledge actuated
by the block during its rotation or by the backward and forward movement of the
carrier.
I sometimes modify the construction hereinbefore described by letting the end of
the block directly close the barrel in which case the extractor is moved by pins in
the same way as the carrier would have been moved.
Dated the 10th day of January 1890.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Breech-loading Small-arms and
Machine Guns.
I, OSKAR WILLIAM BERGMAN, of Gothenburg, in the Kingdom of Sweden,
Lieutenant in the 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 military or sporting rifles or small arms with or without
magazines, and to machine guns operated either by hand or automatically by the
force of the recoil, and it comprises the improvements hereinafter described.
In the accompanying drawings,-
Figure 1 represents a longitudinal sectional elevation of a machine,
gun constructed
according to my invention and adapted to be operated either by hand or by the
recoil, the breech being shewn closed and the mechanism in the position it occupies
immediately after the gun has been fired.
Figure 2 represents a side elevation of the gun with the breech open:
Figure 3 is a plan view of the gun :
Figures 4, 5, 6, 7, 8, 9 and 10 are transverse sections taken respectively on the
lines a b, ef, i k, 1 m, p q, c d and g h of Figure 1:
Figure 11 represents various views of a cartridge feeding belt employed:

page_text: Figures 12 to 22 are views of modifications hereinafter described.
Similar reference letters indicate similar or corresponding parts throughout the
drawings.
In carrying out my invention I provide a frame or box K which encloses the
whole of the mechanism of the gun, the said frame being of bronze or any other
suitable metal, and provided with the trunnions for supporting the gun, the seating
for the elevating screw, the handle J and the sights N, N¹.
My improved breech-mechanism comprises two essential parts, namely, what I
term a block indicated by the letter A, and a bolt or carrier indicated by the
letter B, which block and carrier are located in a breech-piece or frame C at the
breech of the gun, the said breech-piece being attached to the barrel G, so as to
receive the recoil as hereinafter described, and working in guides K'. The block A
is provided with a handle a¹ for the purpose hereinafter described, and is pivoted on a
horizontal pin or axis I at the rear part of the said breech-piece; and the carrier B
is adapted to be moved horizontally forwards and backwards in guides C' in the
said breech-piece by means of a stud b', attached to the said carrier and entering a
cam-groove a³ formed in the said block A, so that, when the block A is moved or
oscillated upon its pivot I to open the breech as hereinafter described, the carrier
will be drawn back, and when the block is moved to close the breech the carrier
will be again moved forward. The shock of the discharge is thus received by the
carrier supported by the block, which, by its axis, transmits the pressure to the
breech-piece or frame C. A portion of the groove a³ with which the carrier is in
engagement when the breech is closed is made concentric with the axis I upon which
the block turns, so that the said carrier is allowed to remain stationary during the
first part of the movement of the block; the other part of the groove is so shaped
as to rapidly move the carrier backwards during the remaining part of the movement
and vice versa when the breech is to be closed. The breech-piece is provided with
openings c², c³ to allow of the feed of each cartridge and the ejection of the empty
shell respectively.
On the block A and concentric with its axis or pivot I is formed a segment of
cog-teeth a which engages with a rack H fixed to the frame K, so that during the
movements of the breech-piece C, the block A. is made to turn on its axis I to open
and close the breech. The pin I is located in slots I* in the frame K so as to
enable the said pin to move relatively to the said frame during the movements of
the breech-piece C.
Motion is advantageously imparted to the breech-piece C and consequently to
the block A by means of a crank-handle U, which can work either to and fro or in
a continuous circular direction, the said motion being imparted through the medium
of a pin attached to but eccentric with the pivot of the handle U and provided
with a bush u' working in a groove u in a slide V attached to the pin I.
At one side of the frame K is a spring-catch W, the boss of which has a bearing
and slides in the said frame, as shewn in Figures 3 and 4, which catch is provided
with a projection working in a spiral groove in the pin I, so that by turning the
said spring-catch, the pin I can be engaged with or disengaged from an opening v¹
in the slide V, in order that the gun can be worked either by hand or by the
recoil as hereinafter described.
The pin or pivot I is provided with a groove in which engages a projection on
the breech-piece so that the said pin is prevented from turning when operated by
the spring-catch W.
The carrier B has attached to it extractors *, 6 for withdrawing the empty
cartridge shells from the chamber of the barrel G and a firing-pin D which
passes through the said carrier. In order to withdraw the firing-pin D after firing
it is provided with an inclined shoulder d against which impinges a lug d' on the
block A when the said block is moved to open the breech. is a spring which
engages with notches in the firing-pin D to retain it in its different positions.
E is the hammer for striking the firing-pin D, which hammer is placed in a groove
in the block A in such a position that, when the block A is moved to open the

page_text: breech, the said hammer will be cocked, as hereinafter described; or the firing-pin
itself, actuated by a spring, can be cocked directly by a stud moved by a second
cam-groove in the block A.
Partly inside the hammer is the main-spring F which serves to move the hammer
forward against the firing-pin D, and on the top of the hammer is a notch e', with
which the sear of the trigger L engages when cocked, it being kept in engagement
with the hammer by the spring. The hammer E has a lug e² which, when the
block A rotates, is acted upon by an inclined planes on the breech-piece C and
draws back and cocks the hammer, so that the trigger L engaging with it, retains
it in the cocked position.
For operating the trigger I provide a trigger-rod O which is arranged in the
frame K, as shewn, one end o² being in a convenient position to be operated by the
thumb of the hand holding the handle J while the other end, which is inclined, is
underneath an arm 12 on the trigger L, the said arm being also inclined to corre-
spond with the incline on the said end of the rod O. By this arrangement,
assuming the hammer be cocked and the block A closed down, if the trigger-rod O
is pushed forward by the thumb, the incline on the said rod acting upon the incline
on the arm will lift up the trigger L. The hammer thus released will be driven
forward by the main-spring F and strike the firing-pin D which then fires the
cartridge. The trigger-rod is returned to and kept in its normal position by a
spring o³. By keeping the trigger-rod O in its forward position, the trigger L will
be operated each time the block A. is moved down to close the breech, by reason of
the incline on the arm 12 striking the incline on the said rod O.
The cartridges are fed to the gun by means of a feed-belt Q of special
construction and a worm R placed beneath a lid or cover P which is hinged to the
frame K behind the chamber of the gun and fastened down by a catch p¹. As,
however, the worm R forms the subject of an application for Letters Patent dated
November 6 1890 No. 17857 no claim is made thereto in this application. The
worm R is provided with a spiral groove r¹ which engages with one end of a lever S.
The spiral groove is endless, that is to say, one half is formed in one direction
round half of the circumference of the axis of the worm R, and the other half is
formed in the opposite direction round the other half of the said circumference so
as to join the first half, as shewn clearly in Figure 6, so that if the end of the
lever S be oscillated, the said worm will be caused to make a complete revolution in
one direction. The lever S is oscillated through the medium of a rod T by the
forward and backward movement of the barrel &.
M is a cranked lever, one arm of which is normally located above the top of the
rim of the cartridge to be fed into the barrel and serves, when its other arm is
operated upon by a shoulder at the end of a slot in the carrier B, to depress
the lower part of the flange of the cartridge into the way of the said carrier as
hereinafter described. m' is a spring which engages with notches in the lever M to
hold it in its different positions.
The feed-belt Q consists of a belt or ribbon of flexible steel, cotton or other
suitable material. To this ribbon are rivetted or otherwise fixed a number of clips
of steel or other suitable material. Each clip consists of flexible or elastic
arms q', q² which serve to hold a cartridge, as shewn in Figure 11. A flange q³ on
the clip prevents each cartridge from moving rearwards, and the edges at the rear
end of the arms of each clip are inclined, so that, when the cartridge is pushed
therefrom by the carrier B, its flange will impinge against the said inclines and so
force the cartridge out of the clip, when it will drop in front of the carrier and be
forced into the chamber g. When in use the feed-belt Q is placed transversely
across the gun between the frame K and the cover P so that some of the clips
containing cartridges are kept between the convolutions of the worm R. The belt
can at any time be removed from the gun simply by lifting the cover P after having
released the catch p¹ which keeps the said cover securely in position.
X is a spring which serves to give the forward movement to the barrel and
mechanism, the spring being placed in a recess in the frame K in the rear of the

page_text: breech-piece and bearing with one end against the said breech-piece and with the
other against a stop Y.
The operation of the gun by hand is as follows:- that is to say, assuming the
mechanism to be in the position shewn in Figures 1, 3 and 4 the spring-catch W
must be turned so as to engage the pin I with the slide V and thus connect the
handle U with the mechanism. One end of the feed-belt Q is then passed into the
opening below the cover P in a direction transversely of the gun and the first
cartridge is placed against the thread at one end of the worm R. By turning the
handle U the breech-piece C and barrel G will be drawn back and thereby cause
the block A to turn into the position shewn in Figure 2, the block in its movement
drawing back the carrier B by means of its cam-groove a³, cocking the hammer and
withdrawing the firing-pin as hereinbefore described.
By the movement of the breech-piece the worm R will be caused to revolve, by
reason of the rod T acting upon the lever S as hereinbefore described. By
continuing the turning of the handle the said cartridge is brought by the worm
above the opening in the breech-piece in which the carrier slides, at the front of
the said carrier but in the rear of the chamber g and thus in loading position, the
shoulder b² of the slot 63 in the carrier B just prior to the said carrier reaching the
end of its backward movement, impinging against the lower arm of the lever M,
end thereby causing the lower part of the flange of the cartridge to be depressed
into the way of the said carrier as hereinbefore described.
The extreme rearward position of the mechanism is attained by a half revolution
of the handle U, by continuing the movement of the said handle (or by moving it
back), the mechanism will move forward, that is to say, the breech-piece C will be
moved forward and cause the block A to move down and close the breech and
thereby cause the bolt or carrier B to move forward, and push the cartridge into
the chamber 9, the cartridge as it is being pushed forward descending, by reason of
the inclined edges of the arms of the clip which hold it acting upon its flange as
herein before described, the said flange passing behind the two extractors, b
g is an incline just in front of the chamber g which serves to direct the point of
the cartridge into the said chamber in case the cartridge should tip up.
The forward movement of the mechanism having been accomplished and there-
fore the complete rotation of the handle U, the trigger-rod O can be pushed
forward whereby the trigger L will release the hammer E which will strike the
firing-pin D and fire the cartridge.
By again operating the handle U another cartridge will be fed by the worm R
to the gun and a similar cycle of operations will be effected by the other parts of
the mechanism to those described, with the addition that the empty shell will be
withdrawn from the chamberg by the carrier B and will be ejected by falling
through the opening c³. By this arrangement it will be seen that a rapid fire can
be maintained by a constant rotation or to and fro movement of the handle U and
by keeping the trigger-rod O depressed.
To enable the gun to work by the recoil due to the explosion of the cartridges,
the pin I must be withdrawn from the slide V by means of the spring-catch W,
thus putting the handle U out of use.
Assuming the cartridge-belt Q has been placed in position as hereinbefore
described, the operation of loading and firing the first cartridge must be effected
by hand in the following manner, that is to say, the block A must be lifted by
means of its handle a¹, thereby causing the carrier B, breech-piece C and barrel G
to move to their extreme rear positions, the hammer to be cocked and a cartridge
placed ready to be pushed into the chamber g, in the same manner as when the
handle U was moved the first half of a revolution as herein before described. If
now,
the block A is moved down and closes the breech, the mechanism of the gun
will be operated as when the handle U was moved the latter half of a revolution
will
as hereinbefore described, so that, if the trigger-rod O be depressed, the
be fired and the recoil due to the firing will move the barrel and breech-piece into
their rearward positions, and thereby the other parts of the mechanism into the
gun

page_text: positions due to such movement. At the same time the spring X is compressed,
the next forward movement of the parts being effected by the expansion of the
said spring, so that if the trigger-rod be still depressed, the gun will again be fired
and so on until the supply of cartridges is exhausted.
In some cases instead of employing a block which merely oscillates upon its axis,
I employ a block which completely rotates and has a continuous cam-groove; in
this case one part of the cam-groove is advantageously formed to withdraw the
carrier while the other serves to return it to its normal position. This arrangement
is shewn in Figures 12 and 13 which respectively represent a machine gun in
sectional elevation and sectional plan, and Figure 14 is a transverse section on the
line no, Figure 12.
a³ is the continuous cam-groove in the block A, the stud or roller b¹ of the bolt
or carrier B engaging therewith. If the block A be turned in the direction of the
arrow, Figure 12, it will be seen that the upper part of the groove will withdraw
the carrier from the barrel when the block is turned half a revolution and the
lower part of the groove will push it in again when the second half revolution of
the block is completed.
Figures 15 and 16 shew an elevation and horizontal section respectively of a
block by which the carrier B is withdrawn when the said block has turned a quarter
of a revolution, and by continuing the revolving of the block in the same direction
the next quarter of a revolution will push the carrier forward and the last half
revolution will again withdraw and move forward the carrier.
Motion is advantageously imparted to the block A, Figures 12, 13 and 14,
by means of a handle U fixed to the axle I. This handle makes a complete
revolution.
In this arrangement the necessary movements can also be effected by utilizing
the force of the recoil when the arm is fired. For this purpose the barrel G and
the breech-piece or frame C are adapted to slide in guides K'in the frame or box K.
The necessary rotary motion can advantageously be imparted to the block by the
following means. 2 is a pinion on the axle I. H is a bar provided with an oblong
hole H having toothed racks at the top and at the bottom and a slot 2 provided
with an incline at each end, the said bar being pivoted on a pin ', in order that
it may be moved to engage either of its racks with the pinion as hereinafter
described. is a spring attached to the breech-piece C and provided with a stud
at its free end which enters the slot h² in the bar H. When the block and other
mechanism of the gun are moved back by the recoil, the pinion * being engaged
with the rack at the top of the hole H' will cause the block to turn. Just before
the breech-piece reaches its extreme rearward position the stud on the spring h³
will impinge against the incline at the rear end of the slot H' and during the
remainder of such backward movement will cause the bar H to turn on its pivot
and bring its lower rack into engagement with the pinion 2, thereby causing the
block to continue its rotation on the forward movement of the mechanism, and just
before such movement is completed the before inentioned stud will impinge against
the other incline of the hole H₁ and move the bar so that its top rack comes again
into engagement with the pinion 2 and so on.
In feeding the cartridges to the gun shewn in Figures 12, 13 and 14, I prefer to
use the same arrangements of mechanism as in the gun illustrated in Figures 1
to 11, the different operations being carried out in the same order as described with
reference to those figures.
I sometimes advantageously employ a rotating block having duplicate cam-
grooves, as I am thereby enabled to dispense with the use of springs for performing
any of the operations of the mechanism, the force of the recoil being employed for
this purpose, light springs being merely necessary for returning the barrel to its
normal position without any turning of the block then taking place. To prevent
the cartridges from being fired prematurely, I arrange the trigger-arm O so that it
cannot act upon the trigger L before the barrel is home; or other suitable arrange-
ments may be employed.

page_text: The rotating block is in some cases made with the parts carrying the two cam-
grooves in different planes, so that one part of the block will work in connection
with one barrel and the other part with another barrel. Figures 17 and 18 are
respectively an elevation of one of such blocks and a horizontal section of part of a
gun shewing the said block applied thereto, and Figures 19 and 20 are respectively
an elevation and horizontal section of another form of block, the block in each case
being arranged to operate in conjunction with two barrels.
In Figures 17 and 18 the carrier B2 is in the firing position when the other
carrier B is in its most rearward position, a lug a' on the block being behind
a shoulder B³ in the carrier B2, and thus in a position to transmit the strain
due to the explosion of the cartridge through the block to the pivot-pin of the
block and breech-piece C. With the block illustrated in Figures 17 and 18 one
shot will be fired at every half revolution of the block, and with that illustrated
in Figures 19 and 20 one at every quarter revolution.
Figure 21 is a sectional elevation illustrating an adaptation of the constructions
hereinbefore described to a rifle. In the said figure the carrier B is dispensed
with and the block A serves to close the barrel, as shewn. The cartridge is
pushed into the chamber and the shell extracted again, by a piece B shewn
detached in Figure 22, which piece has a lug engaging in a groove a³ in the
block A. and which slides in the breech-piece C. All the parts belonging to
the firing mechanism are located in the block A. In order to get an oscillating
movement of the block A, when the mechanism is recoiling, I preferably use a
As the block
pin H fixed to the gun and working in a slot a² in the block A.
with its centre I is recoiling the pin H, being stationary, will cause the said
block to oscillate on its centre and open the breech and extract the empty
cartridge-shell, and a fresh cartridge will be moved in place for loading by a spring
from a magazine underneath, or otherwise. When the mechanism is again moving
forward the block A will be caused to push the cartridge forward by the piece B
and close the breech, thereby preparing the gun ready for firing. This adaptation
I prefer to employ principally for rifles, as shewn, or other small arms.
obvious that the pin H and slot 2 can be used in the machine gun shewn in
Figures 1 to 10, instead of the toothed segment and rack described.
It will be
In order to avoid overheating the barrel with rapid firing, I sometimes use a
stream of water which I cause to circulate round the barrel, and I prefer an arrange-
ment by which I only allow a small quantity of water to come in contact with the
barrel for each round.
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. The employment in a fire-arm of a block having an oscillating or rotary move-
ment, and having a cam-groove giving a rectilinear movement to a bolt or carrier
which serves for the introduction of cartridges into, and the extraction of empty
shells from the chamber of a gun barrel, substantially as described.
2. In a fire-arm, an oscillating or rotating block having a cam-groove therein and
provided with a spring-hammer for igniting cartridges through the intermediary of
a striker or firing-pin, substantially as described.
3. A fire-arm the cocking of the hammer and firing-spring of which is effected
by the oscillating or rotating movement of a cam-block, substantially as
described.
4. In a fire-arm having an oscillating or rotating block, the employment
of a rack and toothed sector for giving movement to the said block, substantially
as described.
5. In a fire-arm, the employment of a movable cover which allows a feed-belt
to be laid in position or taken away without other manipulation than moving the
said cover, substantially as described.
6. In a fire-arm, the employment of a crank-handle which, when receiving a

page_text: continuous rotary motion, will give to the barrel and breech-piece a forward
and backward movement and thereby effect the different operations of closing and
opening the breech, feeding the cartridges, firing the same, and extracting and
ejecting the empty shells, substantially as described.
7. In a fire-arm, means, substantially as hereinbefore described, which will allow
the said arm to be fired, either by hand by a continuous rotary motion of a. crank-
handle, or by the force of recoil due to the explosion of the cartridges in the
chamber of the barrel.
8. In a fire-arm, means for allowing the crank-handle to remain stationary while
the arm is worked by the force of recoil, substantially as described.
9. In a fire-arm, the construction of the crank-handle and the parts which transmit
its motion in such a manner that the said fire-arm may be operated, either by a
continuous rotary motion or by an oscillating or to and fro motion without affecting
the normal working of the gun, substantially as described.
10. A feed-belt for use in a fire-arm provided with elastic arms or clips so con-
structed that cartridges held by the said elastic arms or clips are ejected by the
breech-bolt or carrier, which pushes them forward at the same time depresses them
by means of inclined edges, substantially as described.
11. A feed-belt for use in a fire-arm, provided with clips, each of which consists
of two flexible arms and a flange, which flange serves to prevent the rearward move-
ment of the cartridge, substantially as described.
12. The improved machine gun consisting of the parts constructed and combined
substantially as described with reference to Figures 1 to 10 of the drawings, and
operating as, and for the purposes, set forth.
-.
13. The modifications of my invention, substantially as described and illustrated
in Figures 12 to 22 of the drawings.
Dated the 10th day of Novembar 1800
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.