IMPROVEMENTS IN MACHINE GINS
Year: 1882

page_text: LETTERS PATENT to Thorsten Nordenfelt of N° 53 Parliament Street in
the City of Westminster for an Invention of "IMPROVEMENTS IN MACHINE
GINS"
PROVISIONAL SPECIFICATION left by the, said Thorsten Nordenfelt at the
Office of the Commissioners of Patents on the 14th October 1882.
THORSTEN NORDENFELT of N° 53 Parliament Street in the City of Westminster.
"IMPROVEMENTS IN MACHINE GUNS
"
This Invention has for its object improvements in machine guns, and it relates
especially to simplification of the construction and improvements of the details of
that class of gun now well known as the Nordenfelt gun and which have the
barrels arranged side by side in a horizontal plane in the fore part of a rectangular
frame. The barrels are inserted from behind through the centre cross piece of the
frame and kept in position by lugs on their breech ends and the cover hinged to
the top of the centre crosspiece. Or the barrels can also be screwed into the
centre cross piece, the front cross piece being then passed over their muzzles and
secured to the side arms of the frame by keys or bolts. The barrels have flats
upon them and corresponding projections on the front crosspiece, prevent them
unscrewing.
.
The action block which holds the plungers, firing pins and firing springs is so
short that it does not as heretofore reach over the rear end of the frame when it is
at its rearmost position; it is provided with a cam slot on its under side by which
through a friction roller on the action lever, it receives its sliding motion backwards
and forwards.
At the front end of the action block below the plungers is a projecting plate,
carrying oblique studs which working with corresponding inclines in the cartridge
receiver shifts the cartridge receiver at the end of the rearward and beginning of
the forward motions of the action block, in order to feed the gun.
The firing pins each surrounded by its spring are placed in holes drilled through
the action block and part of the plungers, protrude behind the action block through

page_text: the spring bar which is in two pieces. They are each provided with a lug on the
underside and these lugs nro slanted or bevelled off at their rear in order to
move laterally the trigger comb, which lies at the rear end of the frame. The
trigger comb is held on one side, say to the left, by a spring; and is provided with
studs or lugs for retaining the firing pins. These studs or lugs are slanted or
bevelled off on one side to correspond with the slant on the firing pin lugs, which
being pressed against tiem in the rearward motion of the action block moves the
trigger comb to the right until the firing pin lugs liave passed the cocking lugs.
The spring then brings the comb to the left again whereby the cocking lugs comio
in front of the lugs on the firing pins retaining them during the forward motion of
the action block and until they are released by the action lever moving the trigger
comb.
The part of the firing pin above the lug is of a rectangular section and enters a
guiding recess in the rear part of the cover or frame while the lug is working the
trigger comb.
The action of the trigger comb is not dependant on the spring; for if the trigger
comb spring should break or become weak its work will be performed by a bevelled
lug on the action block which comes in contact with the comb and works it over
to the left as soon as the firing-pin lugs have passed.
When the hand lever approaches its foremost position the heel of the nction
lever comes in contact with a stud on the trigger comb bringing this to the right,
releasing the hammers and firing the shots. Further, in case of breakage or
weakness of the trigger comb spring there is another stud on the comb which is
touched by the same heel of the action lever when this goes back again, bringing
the comb to the left; this stud is so, placed that the comb-is moved the required
distance, and is then held in position by the heel until it is time for it to be moved
by the firing pins. I can also arrange the cocking mechanism so that the hammers
or firing pins do not work the trigger comb to the sido, in which case I save some
of the labour which is required, for overcoming the pressure of the trigger spring.
Instead of having a spring to press the trigger comb over to one side I place a
spring along the side of the comb in order to make the comb work somewhat
stiffly the spring lins a lug and the trigger comb two notches with which the
lug engages; they are placed as far apart as the length of the stroke of the trigger
comb. The lug on the trigger comb, by means of which the action lever heel
brings the comb back after firing, will in this case be dispensed with.
When the shots are fired the trigger comb is placed so that the cocking lugs are
clear of the firing pin lugs, the comib retains this position until after the firing pin
Jugs have returned past the cocking lugs, and then the bevelled lug on the action
block forces the comb over to the ollier side where it remains until the action lever
heel works it back for firing.
The action lever which by the friction roller upon it works the action block, is
also made to lock the breech at the same time as it moves the trigger comb for
firing. This is done by rounding off both ends of the lever to a radius equal to
their distance from the centre of rotation, and having corresponding concave
surfaces on the action block and on the rear of the frame. These surfaces are so
arranged that the front of the action lever enters the coucave on the action block
when this is fully forward, and before the rear end of the lever has commenced to
'move the trigger comb.
When the shots are fired the blows caused by the explosion press the action
block against the lever, and the lover being supported at the rear transfers the blow
to the frame.
The action lever has a boss which enters a socket in a bracket on the frame.
The boss is tubular and a notch is cut in the side of it at its lower part. The
hand lever has a stud entering the hole in the action lever boss and it has also a
lug to correspond with the notch. The bracket is provided with a flange under-
'neath, it overlaps the socket on one side and serves for the lug to rest upon when,
"the levers are in acting position. The hand lever is thus kept in place thus

page_text: making cross pins and split pins unnecessary for coupling the hand lever to the
action lever.
The hand lever may also be provided with another lug or finger to work the
spreading apparatus. There is a bracket to which the elevating screw is fixed and
which remains stationary. This bracket is grooved to receive a dovetail or guide
at the rear end of the frame and the frame can move horizontally upon it. An
adjustable bolt or pin projects through the bracket and the spreading finger on the'
hand lever acts upon it during firing pushing against the bracket and as the
bracket plate is fixed to the carriage by the elevating screw the gun moves. The
bolt or pin is adjustable by a nut on the rear side of the bracket and graduated
to the required spreading for different distances. The spreading given by the
apparatus is dependant upon the distance of the point of the pin acted upon by the
spreading finger from the centre of motion of the lever, the further the- bolt or pin
is projected forward towards the centre the less movement is imparted. The bolt
or pin can also be used as a cramp to fasten the bracket to the gun frame, when no
spreading is required.
•
After firing the gun is brought back to its original position by the spreading
finger acting against a lug on the bracket.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thorsten Nordenfelt in the Great Seal Patent Office on the
14th April 1883.
THORSTEN NORDENFELT of No. 53 Parliament Street in the City of Westminster
IMPROVEMENTS IN MACHINE GUNS"
This invention has for its object improvements in machine guns and it relates
especially to simplification of the construction and improvements of the details of
that class of gun now well known as the Nordenfelt, gun and which have the
barrels arranged side by side in a horizontal-plane in the foro part of a rectangular
frame.
In the Drawings annexed Figure 1 is a plan partly in section and Figure 2 is a
longitudinal and vertical section of a seven barrelled gun constructed in accordance
with my invention.
Figure 3 is a rear elevation of the same and Figure 4 is a transverse vertical
section taken on the lines 1. 1 and 2. 2 in Figure 1.
A. A are the barrels. B the front cross piece and O the centre cross piece of the
rectangular frame. D is the cover which closes over the breech mechanism and
which as in the ordinary Nordenfelt gun has openings in it through which the
cartridges descend from a moveable magazine into the gun. The cover is hinged
at d, to the centre cross piece C. E is the action block and F. F. are the side bars
of the rectangular frame which near their rear ends also serve to guide the action
block in its movements to and fro. G are the plungers by which the cartridges
are thrust into the barrels and the breeches closed behind them. The plungers are
armed with extractors as usual to draw the cartridge cases out of the barrels.
Hare the strikers or firing pins for firing the cartridges. I are the springs for
throwing the strikers forward.
K is the action lever by which the parts are moved.
A is the cartridge receiver into which the cartridges fall from the magazine and
which carries the cartridges to the barrels. The cartridge receiver has openings
through it as usual for the delivery of the cartridge cases when they are withdrawn
from the barrels. N is the trigger comb which retains and releases the strikers at
the proper times.
O is a part of the support on which the gun is carried.
P is the upper end of the elevating screw connected with O by an universal
joint.
Qis a clamp also forming, part of a spreading arrangement herein-after
described.
Tis the hand lever for working the gun.
I will now proceed to explain the novel features which these parts present.
I have represented two different arrangements for fixing the barrels in their
places, one of these is illustrated by the Figures 5. 6. 7. 8 and 9. Figure 5 is a
vertical section Figure 6 a rear elevation and Figure 7 a plan of a portion of the
centre cross piece of the frame with a part of one of the barrels and a portion of
the cover. Figure 8 is a side elevation and Figure 9 is a plan of a portion, of the
fore part of the frame and of one of the barrels. As shown in these Figures the
barrels. A are inserted from behind through the centre cross piece C and front cross
piece B of the frame and kept in position by lugs a. on their breech ends and the
cover D hinged to the top of the centre crosspiece.
Another method of securing the barrels is represented in Figures 1 and 2. The
barrels are in the usual way screwed into the centre cross piece. The front

page_text: cross piece is then passed over their muzzles and secured to the side arms of the
frame by keys or bolts. The barrels have flats upon them and corresponding
projections on the front cross piece prevent them unscrewing.
Figures 10 shew the forms of the holes and recesses in the crosspiece B and of
the flats upon the barrels which render it impossible for the barrels to turn when
the cross piece is in its place and secured by the keys flfl.
The action block E which holds the plungers G firing pins H and firing springs I
is so short that it does not as heretofore reach over the rear end of the frame when
it is at its rearmost position, It is provided with a a cam slot e. on its underside by
which through a friction roller on the action K it receives its sliding motion
backwards and forwards.
At the front end of the action block E below the plungers is a projecting plate L
carrying oblique studs 1. and . which working with corresponding inclines m.
and m. in the cartridge receiver M. shifts the cartridge receiver at the end of the
rearward and beginning of the forward motions of the action block E in order to
feed the gun.
The first movement places the recesses in the cartridge receiver beneath the
openings in the cover so that cartridges may fall into them from the magazine and
the second movement carries these cartridges to the barrels ready to be thrust into
them by the plungers G on the further advance of the action block.
The firing pins H each surrounded by its spring. I are placed in holes drilled
through the action block and part of the plungers and protrude behind the action.
block, through the spring bar e³. which is in two pieces. They are each provided
with a lug h on the underside and these lugs are slanted or bevelled off at their
rear in order to move laterally the trigger comb N which lies at the rear end of
the frame. The trigger comb is held to one side, say to the left, by a spring n. and
is provided with studs or lugs n for retaining the firing pins. These studs or lugs
are slanted or bevelled off on one side to correspond with the slant on the firing pin
Jugs h. which being pressed against them in the rearward motion of the action
block E moves the trigger comb N to the right until the firing pin lugs h have
passed the cocking lugs n. The spring n'.. then brings the comb N to the left again
whereby the cocking lugs n come in front of the lugs h on the firing pins
retaining them during the forward motion of the action block E. and until they are
released by the action lever K moving, the trigger comb. N.
The part of the firing pin above the lug is of a rectangular section and enters a
guiding recess d'. in the rear part of the cover or frame while the lug h is working
the trigger comb N.
The action of the trigger comb N is not dependent on the spring n' for if this
trigger comb spring n', should break or become weak its work will be performed by
a bevilled lug el. on the action block which comes in contact with the comb at n³.
and works it over to the left as soon as the firing pin lugs h have passed the lugs n
on the trigger comb.
When the hand lever T approaches its foremost position the heel kl. of the action
lever K comes in contact with a stud n². on the trigger comb N bringing this to
the right releasing the firing pins or hammers H and firing the shots. Further in
case of breakage or weakness of the trigger comb spring n. there is another stud n⭑.
on the comb which is touched by the same heel of the action lever when this goes
back again bringing the comb to the left; this stud is so placed that the comb N
is moved the required distance and is then held in position by the heel until it
is time for it, to be moved by the firing pins.
Sometimes to shorten the mechanism by the length which the striker H in.
Figure 2 projects through the spring bar e³ I form the striker with an arm h' on
its underside to carry the lug h, this modification is shewn in Figure 11.
•
The action lever K which by the friction roller upon it works the action
block E is also made to lock the breech at the same time as it moves the trigger
comb N for firing. This is done by rounding off both ends k'. and . of the lever K
to a radius equal to their distance from the centre of rotation and having

page_text: corresponding concave surfaces on the action block E ate and on the rear of the
frame at f. These surfaces are so arranged that the front of the action lever let;
enters the concave e². on the action block E when this is fully forward and before
the rear end of the lever lias commenced to move the trigger comb N.
When the shots are fired the blows caused by the explosion press the action
block E against the lever K and the lever being supported at the rear transfers
the blow to the frame.
Figure 12 shows a vertical section through the boss of the action lever and the
socket on the frame into which the boss is received. It shews also in elevation a
portion of the land lover and a stud upon it which enters within and engages with
the boss of the action lever. As will be seen the action lever K has a boss k¹.
which enters a socket f³ in a bracket on the frame. The boss 2. is tubular and a
.notch is cut in the side of it at its lower part. The hand lever T has a stud t
entering the hole in the action lever boss, and it has also a lug t' to correspond with
the notch. The bracket is provided with a flange f underneath, it overlaps the
Bocket on one side and serves for the lug t to rest upon when the levers are in
acting position. The hand lever is thus kept in place thus making cross pins-and
split pins unnecessary for coupling the hand lever to the action lever.
The hand lever is easily made to engage with the action lever when the action
block has been removed and when it is in place the two lovers are securely locked
together.
Figure 13 is a plan of the parts concerned in producing the spreading
movement, by which in the act of firing, the position of the gun is slightly varied
so that all the shots may not be planted in the same place.
The hand lever T is provided with another lug or finger t. to work the spreading
apparatus. There is a bracket to which the elevating screw P is fixed and
which remains stationary. This bracket is grooved to receive a dovetail or
guide f. at the rear end of the frame, and the frame can move horizontally upon it.
An adjustable bolt or pin Q projects through the bracket and the spreading
finger t. on the hand lever acts upon it during firing, pushing against the bracket O,
and as the bracket plate is fixed to the carriage by the elevating screw the gun
moves. The bolt or pin Q is adjustable by a nut 7 on the rear-side of the bracket
and graduated to the required spreading for different distances. The spreading
given by the apparatus is dependent upon the distance of the point q' of the pin Q
acted upon by the spreading finger from the centre of motion of the lever T the
further the bolt or pin is projected forward towards the centre the less movement
is imparted.
After firing the gun is brought back to its original position by the spreading
finger acting at ol. against a lug o² on the bracket O. Thus the bracket is brought
up against the stop f' and it is retained there during the further movement of the
hand lever by curved horn or lug o².
The bolt or pin Q can also be used as a cramp to fasten the bracket O, to the
gun frame when no spreading is required. The bolt or pin Q is then drawn back
until it is clear of the spreading finger t. and its head is minde to enter a notch fº.
in the frame.
Figure 14 is a longitudinal and vertical section Figure 15 a plan. Figure 16 a
rear elevation and Figure 17 a transverse section of a four barrelled gun of larger
calibre. The cocking apparatus differs somewhat from that previously described.
I arrange the cocking mechanism so that the hammers or firing pins H do not
work the trigger comb N to the side. I thereby save.souie of the labor which is
required for overcoming the pressure of the trigger comb spring. Instead of having
a spring to press the trigger comb over to one side I place a spring S along the
rear side of the comb in order to make the comb work somewhat stiffly The
spring has a lug and the trigger comb two notches n n with which the lug
engages, they are placed as far apart as the length of the stroke of the trigger
comb N. The lug on the trigger comb by means of which the action lever heel
brings the comb back after firing, will in this case be dispensed with.

page_text: When the shots are fired the trigger comb N is placed so that the cocking lugs n
are clear of the firing pin lugs h. the comb retains this position until after the firing
pin lugs h. have returned past the cocking lugs n. and then the bevelled lug e¹. on
the action block acting against the incline n³. forces the comb N over to the other
side where it remains until the action lever heel ¹ works it back for firing.
In this gun the cartridge receiver M receives movement from the action block E
by means of a stud at the end of an arm L projecting forward from the action
block. The stud is contained in a central passage m provided in the cartridge
receiver M to receive it and at ml. the passage is inclined so that the stud
traversing the passage may impart the desired movement to the cartridge receiver.
In this gun also the action block is locked when the breech is closed by bolts R. R.
pushed out from it into the frame, the bolts are controlled by a slotted lever
rocking on a pivot c. The slotted lever receives movement from the end ct. of the
action lever as in Nordenfelt guns at present in use.
Having thus described the nature of my said Invention and the manner of
performing the same I would have it understood that I.claim
First. The method illustrated by the Figures 5. 6. 7. 8 and 9 for fixing the
barrels in the frame..
Second. The method illustrated by the Figures 1. 2 and 10 for preventing the
barrels unscrewing from the centro cross piece of the frame.
Third. The method illustrated by the Figures 1. 4. 14. 15 and 17 for actuating
the cartridge receiver by inclines and studs."
Fourth. The method illustrated by Figures 1 and 15 for actuating the trigger
comb by means of the action block to ensure that independently of its spring the
trigger comb shall engage with and retain the strikers.
Fifth. The method illustrated by Figure 1 for actuating the trigger comb by
the action lever by which independently of the spring the comb after firing is
replaced.
Sixth. The method illustrated by Figure 1 for locking the breech by providing
bearing surfaces upon the action block action lever and frame.
Seventh. The method illustrated by Figure 12 for coupling the hand lever and
the action lever.
Eighth. The method illustrated by Figures 2 and 13 for obtaining the spreading
movement.
Ninth. The method illustrated by Figures 14 and 15 for retaining and operating
the trigger comb.
Tenth. The machine guns substantially as herein shewn and described.
In witness whereof I the said Thorsten Nordenfelt have hereunto set my
hand and seal this twelfth day of April in the year of our Lord One
thousand eight hundred and eighty three.
THURSTEN NORDENFELT (L.S.)