Improvements in Fire-arms.
Year: 1897

page_text: Improvements in Fire-arms.
I, CARL AXEL TEODOR SJÖGREN, of 28, Jakobsgatan, Stockholm, in the Kingdom
of Sweden, Engineer, do hereby declare the nature of this invention to be as
follows:
This invention relates to an arrangement of fire-arms, consisting therein that
the breech-bolt, which in its forward position enters the breech like a plunger,
is not locked in its closing position, the weight of the bolt and the length of the
portion of the same, which enters the chamber of the breech, being instead so
proportioned to the weight of the projectile and the length of the bore (barrel)
that, when the fire-arm is discharged, the projectile will have time to leave the
bore before the portion of the bolt which enters the chamber of the breech has.
had time to leave the latter.
The arrangement referred to is chiefly intended to be applied to automatic
machine-guns and small arms, the latter being either arranged as single-loaders
or as magazine-guns.
The breech-bolt which reciprocates in the usual manner in the casing is pro-
vided at its forward end with a narrower head which enters the breech like a
plunger. The head is preferably made slightly tapering so as to cause it to
close gas-tight in the similarly shaped breech chamber. When the bolt has
receded through a slight distance a gas-tight closure is effected by the expansion
of the cartridge-case. Besides being made to enter the barrel, the breech-bolt
is so arranged that its weight and the length of the portion of it which enters
the breech bear such a relation to the weight of the projectile and the length
of the bore that, when the gun is discharged, the projectile will have time to leave
the bore before the head of the bolt has had time to leave the chamber of the brecch,
ample safety being thus insured from a too early opening of the breech. As
the breech-bolt recedes, the spring which enters the bolt and acts on the firing-
pin, is compressed and the cartridge-case is extracted by the extractor. The
lever which is attached to the breech-bolt and' which with one end acts on the
firing-pin and at the other is actuated by a projection, is simultaneously rotated,
thereby cocking the firing-pin. The lever is locked by the scar which on the
closing of the breech can be released by the trigger and the trigger lever. In
its extreme rear position the breech-bolt is locked by the latch which in its up-
ward motion pushes the empty case upwards and ejects it from the gun. When
a fresh cartridge is inserted, the latch is depressed by said cartridge and the spring.
pushes the released bolt into its closing position, the gun being. then ready for
firing. The casing is suitably made open towards the breech-bolt so as to admit
the latter to enter the casing with its rear end, for the purpose of forming an air-
cushion behind the recoiling bolt.
"
As a special advantage of the invention described above, apart from its auto-
matic action, there may be mentioned that, inasmuch as the return motion of
the bolt in this gun corresponds to the recoil of an ordinary gun while the pro-,
131*
[Price 8d71

page_text: jectile is passing through the barrel, the recoil in the present gun will be retarded
to such an extent that it will not have time to disturb the sighting of the gun
and affect the direction of the projectile.
Dated this 17th day of July 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Fire-arms.
I, CARL AXEL TEODOR SJÖGREN, of 28, Jakobsgatan, Stockholm, in the Kingdom
of Sweden, 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 to an improved arrangement of fire-arias, consisting in
that the breech-bolt is not locked in its closed position and is given such a
shape that in the position mentioned it will enter the cartridge-chamber of the
barrel like a plunger. Moreover, the breech-bolt is so proportioned as regards
its weight and the length of its plunger-like part in relation to the weight of the
projectile and the length of the bore (barrel) that in firing the projectile will
have time to leave the barrel before the plunger-like part has had time to with-
draw from the cartridge-chamber. After the recoil the breech-bolt is advanced
by one or more spiral springs.
The arrangement referred to is chiefly intended for use in machine-guns and
small arms, the latter being either arranged as single-loaders or as magazine-guns.
In the accompanying drawing I have shown my invention applied to
níagazine-gun.
a
Figure 1 is a longitudinal section of such a gun with the breech-bolt in its
closed position.
'
Figure 2 is a longitudinal section with the breech-bolt withdrawn.
Figure 3 shows the arrangement of the return-spring when one such spring.
only is used.
Figure 4 shows the gun partly in plan and partly in section having two return-
springs.
Figure 5 shows the gun in plan having one return-spring only.
Figure 6 is a transverse section, one part being on the line a-b and the other
part on the line cd of Figure 1, and
Figures 7, 8 and 9 show transverse sections respectively on the lines e-f, g-h
and k of Figures 1 and 5.
The principal parts of the gun are the casing 1, the breech-bolt 2, the barrel 3,
the return-springs 4, 4 located on each side of the latter, the rods 5 connecting
the springs and the breech-bolt 2 with each other, the firing-pin 6, the hammer 7,
the pawl 8, the lever 9, and the trigger 10.
The casing 1 is provided at the back with an end-piece 11 that is inserted into
it from above and held in place by the catch 12. By pressing on the latter and
taking up the piece 11 the casing 1 can be opened when it is desired to remove
any of the parts contained therein, the latter being taken out through the rear end
of the casing. In the casing 1, the forward end of which is firmly screwed on to the
No latch
barrel at 13, the breech-bolt is adapted to slide in the usual manner.
is provided for locking the breech-bolt in its forward position, the said bolt
being held in this position by the springs 4, 4. The latter are located each in a
tube 14 at the sides of the barrel, bearing at the forward end against a washer

page_text: or the like on each rod 5, and at the rear end abutting against the front end of
the casing (at 15, Figure 4).
The rods 5, 5 are extended into the casing, at the inner surface of which
grooves 16 are cut out to receive them, and engage with the breech-bolt by means
of their hooked ends 17, as may be seen from Figures 4, 5 and 6. At its for-
ward end the breech-bolt is provided with a narrower part as at 18 forming the
plunger previously mentioned, the said plunger when the breech-bolt is advanced
into its forward position entering into the cartridge-chamber of the barrel, as
shown in Figure 1. The plunger is preferably made slightly tapering so as to
close up tightly in the cartridge-chamber which is corespondingly shaped.
When the breech-bolt is withdrawn, the hammer 7 mounted on the pin 19 in
the casing 1 is moved into the position shown in Figure 2, at the same time
placing the spring 20 in a state of tension the said hammer being engaged by the
pawl 8. The latter is also attached to the casing 1, being pivoted on the pin 22.
In the position of the hammer shown in Figure 2 the firing-pin 6, which is slightly
movable to and fro in the breech-bolt 2, is held back by the spring 23, so that.
its forward point does not project beyond the forward end of the breech-bolt.
The releasing of the trigger 10 which latter occupies the position shown in
Figure 2 after the last discharge and has a tendency to move forward under the
action of a spring 24 acting upon the lever 9, will cause the said part 9 which
is hooked at its forward end to engage with the notch 25 of the part 8, and the
next discharge can now take place. The part 8 is provided with a projecting
lug 21 which. when the said part 8 has been disengaged from part 7 by the
part 9, disengages the part 9 from 8, so as to enable the latter to engage with the
hammer in the next receding motion of the breech-bolt.
The discharge is effected by the released hammer striking the firing-pin 6,
Figure 1. The breech-bolt not being locked in position immediately begins its
recoil, owing to the pressure of the powder-gases; the weight of the breech-bolt
and the length of the plunger 18, however, are so proportioned that the projectile
will have ample time to leave the barrel before the plunger has been disengaged
from the cartridge-chamber. When the breech-bolt has receded a slight distance
obturation (or a gas-tight fit) in the cartridge-chamber is effected by the cart-
ridge-case accompanying the breech-bolt and expanding so as to conform to
the taper of the chamber.
In the receding-motion of the breech-bolt the springs 4, 4 are compressed the⚫
breech-bolt being finally stopped by the end piece 11. In this position of the
breech-bolt a cartridge rises from the magazine 26 to the level of the bore of
the gun, at the same time ejecting the spent cartridge, which has receded further
in the manner previously mentioned, the breech-bolt subsequently returning to.
the position shown in Figure 1 and at the same time inserting the fresh cart-
ridge into the barrel. The gun is now ready for firing.
It is also possible to insert one cartridge at a time by hand. When with-
drawn the breech-bolt is locked by the bottom 29 of the cartridge-magazine, as
shown in Figure 2 said bottom as usual being elevated by means of a spring 28.
By depositing a cartridge on the said bottom and depressing the latter by means
of the cartridge the breech-bolt is released and the cartridge inserted by the said
bolt into the barrel. In order to admit of opening the breech-bolt by hand, the
breech-bolt is provided with a detachable handle 27.
In the modified arrangement shown in Figures 3, 5 and 9 a return spring 30
is wound directly around the barrel, the rear end of said spring being fastened
to a sleeve 31 movable on the barrel, while its forward end is made to embrace
a conical portion 32 on the barrel. The rods 5 are attached to the sleeve 31.
The manner of operation is the same as that previously described, the sleeve how-
ever in the recoil bringing up against the abutments 33 and 34, Figure 3, simul-
taneously with the striking of the breech-bolt against the end piece 11, the
stresses being thus advantageously distributed over several parts of the gun. By.
rotating the rods 5 so as to bring the hooks 17 out of engagement with the breech-

page_text: bolt, the recesses in the latter for the hooks being for this purpose made wide
at the top (Figure 6), the breech-bolt can be detached.
As special advantages of the gun herein before described I may mention on the
one hand its automatic action by which the gun is made quick-firing and on the
other hand, that, owing to the fact that the receding motion of the breech-bolt
corresponds to the recoil of an ordinary gun while the projectile is passing through
the bore of the gun, the recoil in the present gun is so retarded that it has no
time to exert a disturbing effect on the sighting of the gun. Moreover the gun
is distinguished by its great simplicity owing to the absence of any locking-
motion for the breech-bolt, the danger of a derangement of the gun consequently
being greatly lessened as compared with the guns heretofore employed.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, "I declare that what I
claim: is:
1. In a fire-arm, the combination of a breech-bolt (2) without locking-arrange-
ment, a plunger-like prolongation (18) of said bolt which prolongation, when
the breech-bolt occupies its closed position enters in the cartridge-chamber of
the barrel to such a length that the projectile, in firing, will have time to leave
the barrel before the plunger has left the said cartridge-chamber, one or more
return-springs (4 or 30) acting upon the breech-bolt, and in the latter a firing-
pin (6) for discharging the gun substantially as shown and described.
2. In a fire-arm, the combination of a breech-bolt (2) without locking-arrange-
ment, a plunger-like prolongation (18) of said bolt which prolongation extends
into the cartridge chamber of the barrel, one or more return-springs (4 or 30),
rods (5) connecting the said springs with the breech-bolt (2), a casing (1) in which
the breech-bolt can slide to and fro, and a detachable end-piece (11) in the latter,
which piece arrests the motion of the breech-bolt, substantially as shown and
described.
3. In a fire-arm, the combination of a breech-bolt (2) without locking-arrange-
ment, a plunger-like prolongation (18) of said bolt, which prolongation extends
into the cartridge-chamber of the barrel, one or more return-springs (4 or 30)
acting upon the breech-bolt, a firing-pin (6) arranged in the breech-bolt, a
hammer (7) acting upon said firing-pin, a pawl (8) for retaining in position the
returned hammer, the latter having placed a spring (20) in tension, and a releas-
ing or trigger mechanism, (9, 10) for disengaging the. hammer, substantially
as shown and described.,
4. In a fire-arm, the combination of a breech-bolt (2) without locking-arrange-
ment, a plunger-like prolongation (18) of said bolt, which prolongation extends
into the cartridge-chamber of the barrel, one or more return-springs (4 or 30)
acting upon the breech-bolt, a firing-pin (6), a hammer (7) adapted to actuate
the firing pin, a spring (2) acting on the hammer (7), a pawl (8) adapted to retain
the returned hammer, a lever (9) adapted to engage with the pawl (8), and a
trigger (10) connected with the lever (9) so as to admit of the release of the
hammer by means of the trigger, substantially as shown and described.
5. In a fire-arm, the combination of a breech-bolt (2) without locking-arrange-
ment, a plunger-like prolongation (18) of said bolt, which prolongation extends
into the cartridge-chamber, a casing (1) in which the breech-bolt can slide to
and fro and which casing is secured to the barrel (3) of the gun, a return-
spring (30) wound around the barrel, a sleeve (31) movable on the barrel and
attached to the rear end of the spring (4) while the forward end of the latter is
attached to the barrel, said sleeve being adapted to abut against the forward end
of the casing (1) which end is screwed on to the barrel, and rods (5) connecting
the sleeve and the breech-bolt, substantially as shown and described.
6. In a fire-arm, the combination of a breech-bolt (2) without locking-arrange-
ment, a plunger-like prolongation (18) of said bolt, which prolongation extends
into the cartridge-chamber of the barrel, a cartridge-magazine (26), a movable

page_text: bottom-piece (29) in the latter said piece being acted upon by spring-pressure
from below and locking the recoiled breech-bolt when the magazine has become
empty, substantially as described and shown for the purposes set forth.
7. In a fire-arm the breech-bolt of which, when in its forward position, enters
like a plunger into the cartridge-chamber (Claim 1), the arrangement by which
the breech-bolt is not locked in position and that the weight of the same and
the length of the part (18) entering into the cartridge-chamber are so propor-
tioned in relation to the weight of the projectile and the length of the bore that
the projectile at the discharge of a shot will have time to leave the bore before.
that part of the breech-bolt, which enters into the cartridge-chamber, has time
to leave said chamber.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.