Year: 1886

page_text: Date of Application, 21st Dec., 1886
Complete Left, 21st Oct., 1887
Complete Accepted, 22nd Nov., 1887
DECEDIE
1 THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster
Civil Engineer do hereby declare the nature of this invention to be as follows :-
:-
In automatic machine guns 1 employ a pair of barrels parallel to each other and
fixed at their breech ends into a cross piece. These parts are carried in a frame and
a magazine from which cartridges are supplied to the barrels is mounted on the cover
of the frame. The cartridges pass down through slits or openings in the cross bar.
The barrels with the cross piece are able to recoil within the frame compressing a
spring, which, by its re-action brings the barrels forward again into the firing
position. A breech piece or block for opening or closing the barrels is mounted on an
axis parallel with them. This axis is immediately below the barrels. A rocking
motion is imparted to the breech piece and when it closes the breech of one barrel
the breech of the other is open. The barrels are not fired simultaneously but
alternately, but the two barrels recoil together at every discharge.
There are inclines upon the breech block and upon the cross piece and these acting
in conjunction with other parts impart the requisite movements. When one barrel is
fired the motion resulting carries the breech block over to the right and when the
other barrel is fired, that is to say, when the next discharge takes place the breech
block is moved to the left.
A three armed piece also placed behind the breech block is in like manner caused
to rock about its axis which is aligned with that of the breech block.
The breech block carries firing pins and the three armed piece a hammer and
also fingers which serve to thrust the cartridges into the barrels or rather support
the cartridge whilst the rearward movement of the barrel causes the cartridge to
be lodged within it.
The routine in working is as follows:-
Commencing with the position in which one barrel is loaded and its breech
closed; the other barrel is at this time open and a cartridge is supported upon the
breech block in rear of the open breech in position ready to enter the barrel when
the recoil takes place the loaded barrel is now fired and the two barrels recoil
together, the recoil causes the cartridge already in position to pass into the empty

page_text: barrel for behind the cartridge there is a supporting finger which prevents the
cartridge from being carried back with the breech piece and barrel. When the
cartridge is fully pushed into the barrel the breech block rocks closing that barrel
and at the same time allowing a cartridge to drop down from the magazine into
the slit or opening of the cross piece.
Towards the end of the recoil the extractor belonging to the barrel last fired comes
against a part of the three armed piece and the extractor is thereby caused to
eject the cartridge case from the barrel.
The reaction of the spring compressed during recoil afterwards again moves the
barrels forward and during that movement a cartridge falls from the slit in the
cross piece in rear of the barrel last fired, and is thus placed into position to enter
that barrel and as the forward movement is completed the hammer, which had
previously been thrust back, is liberated and thrown forward, it strikes the firing
pin and another shot is fired. The operations are then repeated except that as
movements occur in opposite directions at the
before mentioned the rocking
alternate discharges.
The gun can be set to fire continuously so long as cartridges are supplied or to
be discharged only by pulling a trigger.
Dated this 10th day of December 1886

page_text: COMPLETE SPECIFICATION.
Improvements in Automatic or Self Loading Machine Guns.
I, THORSTEN NORDENFELT, of 53 Parliament Street, in the City of 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 :-
In automatic machine guns I employ a pair of barrels parallel to each other and
fixed at their breech ends into a cross piece. These parts are carried in a frame
and a magazine from which cartridges are supplied to the barrels is mounted on
the cover of the frame. The cartridges pass down through slits or openings in
the cross bar. The barrels with the cross piece are able to recoil within the frame
compressing a spring, which, by its re-action brings the barrels forward again into
the firing position. A breech piece or block for opening or closing the barrels is
mounted on an axis parallel with them. This axis is immediately below the barrels.
A rocking motion is imparted to the breech piece and when it closes the breech of
one barrel the breech of the other is open. The barrels are not fired simultaneously
but alternately, but the two barrels recoil together at every discharge.
There are inclines upon the breech block and upon the cross piece and these
acting in conjunction with other parts impart the requisite movements.
When one
barrel is fired the motion resulting carries the breech block over to the right and
when the other barrel is fired, that is to say, when the next discharge takes place
the breech block is moved to the left.
A three armed piece also placed behind the breech block is in like manner caused
to rock about its axis which is aligned with that of the breech block.
The breech block carries firing pins and the three armed piece a hammer and
also fingers which serve to thrust the cartridges into the barrels or rather support
the cartridge whilst the rearward movement of the barrel causes the cartridge to be
lodged within it.
The gun can be set to fire continuously so long as cartridges are supplied or to
be discharged only by pulling a trigger.
In order that my said invention may be fully understood and readily carried into
offect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows a vertical longitudinal section of a gun constructed in accordance
with the invention; the section is taken partly on the line a-band partly on the
line b-c in Figure 2.
Figure 2 is the gun seen from the rear end with the end plate taken away.
Figure 3 is a cross section of the cun on the line in Figure 1 and seen from

page_text: .
Figure 4 is another cross section taken on the line in Figure 1.
Figure 5 is a plan of the gun with the cover detached; the cover with its
feeding plate is shown separately in Figure 6.
Figures 7, 8 and 9 show the mechanism in different positions.
The remaining figures show separate parts and they are lettered in accordance
with the following description.
In Figures 1, 2, 3, 5 and 6 the mechanism is shown ready for firing.
Figures 7 and 8 indicate the position the moment after firing and Figure 9 the
position when the barrels with the pieces attached to them have been driven
backward by the recoil.
In
A is a crosspiece of the same breadth as the inside of the main frame its
under side rests and slides upon two slide planes at the bottom of the frame.
the crosspiece the two barrels are screwed in. There is also a tube B firmly
fixed in the cross piece beneath the barrels, this tube serves as an axis for the
rocking breech block C. In this breech block there is provided a small slide 1
which carries two firing pins and which is moveable longitudinally for a short
distance. The rear end of this plate is slightly bevelled off to the underside.
In the crosspicce
there are two openings over the respective barrels made for
the cartridges to drop through. When the breech block is turned to one side
closing one of the barrels the other side together with a web on the crosspiece A
forms a pocket for receiving a cartridge. The centreline of this pocket is the
same as that of the barrel the breech of which is open. The other breech at this
time is closed by the block and one of the firing pins corresponds with this
barrel.
1
In the tube B there is a spiral spring which presses on the end of an abutment
rod D. The rod is supported and guided in the end plate of the frame and it
passes freely through a lever E. The lower end of the lever E bears against the
rear surface of a piece F fixed on the abutment rod D and the upper end of the
same lever E rests in a slot in the rear end of another lever or hammer G which is
jointed to the body G¹ of a three-armed piece by a small pin. This piece G¹ is able
to turn with D as the axis and also in certain positions is allowed to slide longitu-
dinally on D. The arms G2 and G³ form part of the same piece and have for their
purpose to push the cartridges into the barrels. The fore end of the lever G
operates upon the slide which carries the firing pins. The arm G³ is not shown
in Figure 9. On the end plate of the frame there is applied a pendulum piece H
oscillating with the stud as the centre. The piece H is at its lower part
provided with two lugs which engage with the pin F2 on the abutment piece D.
Moreover the pendulum piece H has on its upper part two other lugs H² H³ on
which the two arms H and H on the axis H alternately abut. Besides these
four lugs the piece H also carries a stud H which when the piece H swings acts
against the lever E and causes this to turn. The axis H which is provided with
a trigger H has besides two other lugs or arms I and 1' (Figure 5). Of these
I supports the spring 12 and the other I bears against one end of a lever 13 which is
mounted on the side of the frame and is operated on by the cross piece A in its
longitudinal motion. Figure 10 indicates the two positions assumed by the lever I³.
In one position it locks the trigger axis H and in the other it leaves it free. The
abutment D (Figure 1) is prevented being pushed backward by the spiral spring in
the tube B by means of two lugs 1 which project from a flat spring Is rivetted on the
underside of the arm F1 belonging to the abutment piece D.
The turning of the breech block C is effected by the projection (2 on the under
side of the breech block and by the projection C on the arm F aided by the
tongue C firmly attached to the lower part of the crosspiece. Figure 11 shows this
tongue and the projection C² seen from beneath.
The feeding fresh cartridges to the barrels alternately is performed by the slide K
mounted in the cover and able to turn with K¹ as the centre; it lies over the cross-
piece A. The two openings in the slide K shown in Figure 6 are so situated that
one or the other coincides with one or the other of the openings in the crosspiece when

page_text: the slide is in its extreme positions. At the same time the other opening in the
slide K corresponds with the magazine and takes a fresh cartridge. The breech block
has two lugs K and K on its top and when the block turns these lugs move the
slide K; the spring K' forces it to its extreme positions.
Supposing that the right barrel is to be fired the mechanism stands as in Figure 2
and the slide K then is in a situation opposite that shown in Figure 6. A cartridge
has now dropped through the right opening in the crosspiece and is supported by
the breech block. When the barrels recede by the recoil and later on when the
breech block turns to the left the cartridge will be still kept in its place by the
spring L.
The back of this spring usually slides in a groove in the frame but at the proper
time for catching the cartridge it is pressed outward by an incline upon the frame
side whilst the new cartridge is kept in this position the cartridge just fired is
extracted. When the recoil has proceeded further the fresh cartridge will be released
and allowed to drop down into the before mentioned pocket formed by the side of
the breech block and the web on the crosspiece. This place the cartridge keeps until
the next recoil takes the barrels backward again and it is then pushed into the
chamber of the barrel by the arm G³.
On turning the trigger axis H the arm H' abuts on the lug H2 on the pendulum
piece which thus is brought to a midway position as shown in Figure 8. During
this motion the stud H' presses against the upper part of the lever E and causes this
and the whole mechanism G G G G³ to turn on the rod of the abutment D. The
pin F belonging to the abutment piece D is also caused to turn but in an opposite
direction. By these motions the lugs I are brought to coincide with notches in the
body of the three armed piece G' and this allows the abutment D to be thrust back
by the spiral spring the three armed piece G¹ at the same time being moved forward
by the lever E. The hammer G now strikes the rear end of the plate C and the
cartridge is fired. When the recoil takes place the head of the hammer G is
depressed and passes under the plate Con account of the bevelled off shape of the
nose of the hammer as well as of the rear end of the plate. As the recoil proceeds
the lug thrusts itself in between the tongue C and a web on the underside of the
breech block being guided by the lug 02. The breech block is thus turned. This
motion of the breech block again brings the three armed piece to turn to its midway
position as indicated by Figure 2.
At the end of the recoil the front part of the hammer G is pressed upward by the
incline P on the breech block and then on account of its shape it draws the plate C¹
slightly backward.
The extraction is performed by the lower end of the extractor striking against the
front end of the arm F¹.
At the rear ends of the two top openings in the crosspiece (see Figure 5) there
are small slides P¹ P² (see Figure 12) able to move slightly in a vertical direction.
These slides are pushed upward by the arms G and G3 on the three armed piece
when this turns and are kept in this position by lugs on the springs L. At the last
part of the recoil the slides are pressed downward by means of an incline on the
cover not shown in the drawings. These slides have for their purpose to prevent
the fresh cartridge placed in the above mentioned packet falling out when the return
movement of the barrels takes place.
In a like manner with the slides P1 P2 the extractors also are kept in their closed
positions by means of other lugs L³ on the springs L.
With the spring I there is connected a lever R; a longitudinal forward movement
imparted to this makes the gun entirely automatic. The spring then causes the
axis H to turn and as before explained the gun is thus fired.
In the rearmost position of the spring it only abuts over the centre of the axis H
so that no turning is now performed by it and the gun then is not discharged until
the trigger is pulled.
The speed at which the barrels return after recoil is regulated by an air cylinder
with an adjustable vent; this the drawings show.

page_text: 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 machine gun substantially as described having two parallel barrels mounted
in a frame in which they are able to slide longitudinally; also a spring which is
compressed by the recoil and afterwards moves the barrels forward; also a breech
block which rocking about an axis closes the barrels alternately; also inclines on
the breech block and upon another rocking part which during the recoil and return
impart the movements to the breech block requisite to open and close the barrels
as herein set forth.
2. A machine gun substantially as described having two parallel barrels mounted
in a frame in which they are able to slide longitudinally; a breech block automa-
tically actuated by the recoil and a spring which is compressed by the recoil and
afterwards moves the barrels forward and which spring also operates against a
moveable abutment and thereby actuates the hammer as heroin set forth.
3. In a machine gun substantially as described, the hammer striking the firing
pin, driving it forward to explode the cartridge and then operating to withdraw
the firing pin as herein set forth.
4. In a machine gun, mechanism substantially as described and represented in
the annexed drawings.