IMPROVEMENTS IN MACHINE GUNS AND OTHER FIRE-ARMS
Year: 1881

page_text: LETTERS PATENT to Thorsten Nordenfelt, of Saint Swithin's Lane, in the
City of London, for an Invention of "IMPROVEMENTS IN MACHINE GUNS
AND OTHER FIRE-ARMS."
PROVISIONAL SPECIFICATION left by the said Thorsten Nordenfelt at the
Office of the Commissioners of Patents on the 20th July 1881.
THORSTEN NORDENFELT, of Saint Swithin's Lane, in the City of London..
"IMPROVEMENTS IN MACHINE GUNS AND OTHER FIRE ARMS."
This mechanism is an improvement on that described in Specification dated
Nov. 4th, 1880, No. 4523, in which the breech block is in two parts, the fore part
of which has a rotary motion, and the rear part a rotary and also a vertical motion.
In my improved mechanism the block will still be in two parts, an upper and
lower; the lower has a vertical movement only, whilst the upper has a vertical and
also a slight horizontal movement (by horizontal is meant motion parallel to axis of
barrel).
The upper block is in the form of a truncated wedge, and carries the firing pin,
hammer, and main spring.
As in the former gun, the extractor is pivotted to breech end of barrel, but in my
new arrangement is at the lower instead of the upper part, and is acted upon by
the descending breech blocks.
The lower block has a cam shaped groove cut in one of its vertical faces, in
which works a friction roller attached to a lever working in a vertical plane;
motion is communicated to this lever through a spindle upon which is keyed the
band lever.
Another improvement consists in making the gun self-feeding; to obtain this
the breech is carried to the rear of the breech blocks and a hopper fixed to the
upper surface; cartridges are allowed to fall one at a time into the breech, and
are advanced into the chamber by a loading arm, which is a bar running parallel
with axis of the barrel, and having projections at the side, which are acted upon
either by a part of the hand lever, or by a separate lever upon the same axis.

page_text: The above mentioned parts act together in the following manner:-The
mechanism is closed when the hand lever fixed to the axis is in its foremost
position. If the hand lever is pulled backward the blocks glide downward; the
earlier motion of the breech blocks is slowly transferred to the extractor, which
then can act with great force in loosening the cartridge case; when the breech
block approaches the end of its movement, the speed of the extractor is incrcased
and the empty cartridge case is thrown out.
The friction roller having passed out of the slot leaves the block stationary,
whilst the hand lever containing its backward motion draws back the loading bar
and so releases a cartridge from the hopper.
The band lever is now in its rearmost position, and the motion being reversed
causes the loading bar to push the cartridge nearly home in the chamber, then the
friction roller entering the slot forces up the blocks which drive the cartridges
right home.
The gun is cocked as the breech block is making its upward movement, and the
hammer released either by the motion of the hand-lever, or by a trigger at the
moment the wedge or upper block is well home.
The following is another arrangement.
The gun may have one or more barrels.
I will more particularly describe the single barrel gun, leaving it to be
understood that if more than one barrel is used certain of the parts will be in
duplicate.
The barrel is screwed into a frame or body; this body is bored to contain a
plunger having two wings, which (when the plunger has forced the cartridge into
the chamber) are turned into corresponding slots in the body.
Both the lateral and rotary motion of the plunger is obtained by a single
movement of a hand lever, which actuates a roller slide having upon its upper
surface a helical cam, which works in a corresponding groove cut in the plunger.
The roller slide runs in slots cut in the body.
The plunger contains the firing pin and a main spiral spring.
The stem of the firing pin is square in cross section, and passes through a stop
nut with a square opening which is screwed into rear end of plunger, thus
ensuring that when the plunger turns upon its axis, the firing pin shall turn with
it. Upon the rear end of the firing pin is formed a disc or cross piece, a projection
upon which runs in a groove cut in the body. In this groove is situated the
cocking spring which retains the firing pin during the forward stroke of the
plunger, and so compresses the main spring until the plunger being turned for
locking, the projection on firing pin head is carried round into another groove, that
for the extractor, presently described and released.
Thus the projection on the head of the firing pin travels in the lower groove
during the backward and forward movement of the plunger, but passes through
circular grooves into and out of the extractor groove when the plunger is turned
for locking and unlocking.
The extractor runs in a groove in the body and lies upon the surface of the
plunger; a projection upon the rear end of the extractor fits into a slot in the
plunger, and is thus driven backwards and forwards with it, but remains stationary
while the plunger is turning; two projections upon the back of the extractor bear
upon the bottoms of the groove in the body until the cartridge is home, when the
hook end rises over the cartridge head and is forced down in front of it by a spring,
which is let into the body and bears upon the front lug of extractor when in
this position only.
The hand lever is pivotted to a jointed bracket which may be folded and fixed
close to body when the gun is not in use, the hand lever at the same time lying in
line with the body and closing the opening underneath.
The cartridges are held in a hopper which is attached to the upper surface of
body; this hopper is kept continually supplied by magazines introduced into the
upper part of it.

page_text: When the hopper is removed a shield made of spring steel or other suitable
material is sprung over the fore part of the body and entirely closes all openings.
A breech cap or bolt which screws on the end of the body keeps the whole of
the mechanism in position.
The roller slide with the cam and the helical slot in the plunger give the plunger
an intermittent lateral and rotary motion.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thorsten Nordenfelt in the Great Seal Patent Office on the
20th January 1882.
$s
THORSTEN NORDENFELT, of Saint Swithin's Lane, in the City of London.
IMPROVEMENTS IN MACHINE GUNS AND OTHER FIRE ARMS."
This mechanism is an improvement on that described in Specification dated
November 4th, 1880, No. 4523, in which the breech block is in two parts, the fore
part of which has a rotary motion, and the rear part a rotary and also a vertical
motion. In my improved mechanism the block will still be in two parts, an upper
and lower, the lower has a vertical movement only whilst the upper has a vertical
and also a slight horizontal movement (by horizontal is meant motion parallel to
axis of barrel).
The upper block is in the form of a truncated wedge and carries the firing pin,
hammer, and main spring.
As in the former gun the extractor is pivoted to the breech end of the barrel,
but in my present arrangement is at the lower instead of the upper part, and is
acted upon by the descending breech blocks.
The lower block has a cam shaped groove cut in one of its vertical faces, in
which works a friction roller attached to a lever working in a vertical plane.
Motion is communicated to this lever through a spindle upon which is keyed the
hand lever.
Another improvement consists in making the gun self feeding; to obtain this
the breech is crrried to the rear of the breech blocks and a hopper fixed to the
upper surface; cartridges are allowed to fall one at a time into the breech, and are
advanced into the chamber by a loading arm, which is a bar running parallel with
axis of the barrel, and having projections at the side which are acted upon either
by apart of the hand lever or by a separate lever upon the same axis.
The above mentioned parts act together in the following manner :-The
mechanism is closed when the hand lever, fixed to the axis, is in its foremost
position. If the hand lever is pulled backward the blocks glide downward; the
earlier motion of the breech blocks is slowly transferred to the extractor, which
thien can act with great force in loosening the cartridge case.

page_text: The friction roller having passed out of the slot leaves the block stationary,
whilst the hand lever continuing its backward motion draws back the loading bar
and releases a cartridge from the hopper.
The hand lever is now in its rearmost position, and the motion being reversed
causes the loading bar to push the cartridge nearly home in the chamber, then
the friction roller entering the slot forces up the blocks which drive the cartridge
right home.
The gun is cocked as the breech block is making its upward movement, and the
Lammer released either by the motion of the hand lever or by a trigger at the
moment the wedge or upper block is well home.
Sheet 1 of the annexed Drawings represents the breech action and other parts
of a machine gun constructed according to this part of my Invention.
Figure 1 is a side elevation; Figure 2, a vertical and longitudinal section;
Figure 3, an horizontal section; Figure 4, a plan; Figure 5, a back view with
the rear parts of the body and feed hopper removed; and Figure 6, a transverse
section.
A is the body or frame into which the breech end of the barrel B is screwed ;
C and D are the two parts of the divided breech block. The lower part C is
moveable up and down in guides A', A¹, on the body or frame, and the upper
part D is also moveable horizontally in guides C', C¹, on the top of the part C.
This compound breech block is actuated by the arm E' on the axis E, the
roller Ex carried by this arm being received into the groove C2, C², on the part Ċ;
E is the lever handle for working the gun; it is fixed on the axis E. The small
amount of horizontal motion which the upper part D of the block requires to press
it firmly against the breech face when the breech block is raised, and to relieve it
from the breech face as the block descends, it receives by means of interlocking
inclines formed upon the body A and upon the part D; these inclines are marked
A* and D*.
F is the loader; it slides horizontally along the guides A2, A3, on the body or
frame. The loader receives its movement from the lever handle E2; there is a
projection Ex thereon, which enters a groove F¹ in the side of the loader.
When the parts are thus engaged the lever handle in its movements carries the
loader with it.
The loader has a finger F2, which dips down into the trough of the body or
frame A;
it carries a hook F*, which aids in withdrawing the case of the cartridge
after firing.
G is the extractor, which operates first on the cartridge case to loosen it and
draw it back a short distance. The extractor is jointed to the body or frame A,
and as the part C of the breech block descends an incline thereon operates against
the lower end of the extractor, thereby imparting a backward movement to
its upper end or nose, which stands in front of the base flange of the
cartridge.
His the feed hopper; it may be made of any convenient height, provided that
by suitable and well known means the cartridges are prevented from jamming and
descend regularly as those below are removed; I, I, are a pair of rockers upon an
axis I carried upon the side of the hopper; I' is a spring tending to retain the
rockers in the position in which they are represented in Figure 5; 1³ is a lug on
the axis of the rockers, which when the lever handle E2 is raised is struck by the
projection Exx on the handle. Thus the lower ends of the rockers are moved
back out of the way of the cartridge resting upon them,, which consequently falls
down into the trough of the frame or body A. The cartridge next above falls at
the same time on to the upper ends of the rockers and is there supported until on
the return movement of the handle the rockers assume again the position in which
the Drawings show them.
The part D of the breech block contains within it the firing pin K, which is
actuated by the lever or striker L, and this is pressed forward by the spring M.
O is a piece carrying an incline Ox. It is pivotted to the body A at Oч and is,

page_text: partly contained in a recess prepared for it, but the lower part Ox stands out of
the recess in the way of the end of the striker L, which. is similarly inclined, as is
seen in Figure 1; 02 is a spring which presses the piece O forward.
When the breech block descends the end of the striker L passes down in front
5 of the piece O, which yields back to allow it to pass, but as the breech block rises.
the end of the striker L comes against the back of the piece O and the striker is
forced back by the incline. As the breech closes the end of the striker L escapes"
over the shoulder at the top of the projecting incline Ox, and flying forward causes
the firing pin K to strike the priming of the cartridge and fire the shot. The
Ostriker does not follow the firing pin when its noze projects beyond the face of the
breech block and the firing pin K returns to the position shown in Figure 3 at the
instant of firing.
P is a bolt, which when pushed in prevents the advance of the striker L when
free of the incline Ox. When this bolt is in the firing is delayed until the bolt is.
drawn back by hand.
The way in which these parts operate together has been already described; as
the lever handle E2 is moved back the compound breech block descends, the
extractor G loosens the cartridge case from the barrel, and the hook Fx on the
loader F draws the cartridge case back till it falls through the hole A³ in the
bottom of the body. Simultaneously with the escape of the case of the cartridge
last fired another cartridge is dropped out of the hopper H into the trough of the
body A in front of the hook F* of the loader.
On reversing the movement of the lever handle E the loader advances and the
head of its hook F* comes against the cartridge lying in the trough. The head
of the hook being inclined, and the hook being loosely jointed to the finger F², it
yields back and the head of the hook passes the base flange of the cartridge, the
finger F itself coming against the same and driving the cartridge forward into the
barrel. The hook F* resumes its position as the loader moves forward, the head
of the hook then passing in front of the base flange of the cartridge. As this
hook is not required to loosen the cartridge it is sufficient to apply a spring, which
yields to permit the head to pass the flange and then causes its immediate
return.
The breech block is grooved upon the face, as is shown, to receive the finger F
of the loader and its hook F*.
The following is another arrangement :-
The gun may have one or more barrels. I will more particularly describe the
single barrel gun, leaving it to be understood that if more than one barrel is used
certain of the parts will be in duplicate.
The barrel is screwed into a frame or body; this body is bored to contain a
plunger having two wings, which (when the plunger has forced the cartridge into
the chamber) are turned into corresponding slots in the body.
Both the lateral and rotary motion of the plunger is obtained by a single
movement of a hand lever, which actuates a roller slide having upon its upper
surface a helical cam, which works in a corresponding groove cut in the plunger.
The roller slide runs in slots cut in the body.
The plunger contains the firing pin and a main spiral spring.
The stem of the firing pin is square in cross section and passes through a stop
nut with a square opening which is screwed into rear end of plunger, thus
ensuring that when the plunger turns upon its axis the firing pin shall turn with
it. Upon the rear end of the firing pin is formed a disc or cross piece, a projection
upon which runs in a groove cut in the body; in this groove is situated the cocking
spring which retains the firing pin during the forward stroke of the plunger and
so compresses the main spring, until the plunger being turned for locking the
projection on firing pin head is carried round into another groove (that for the
extractor presently described) and released.
Thus the projection on the head of the firing pin travels in the lower groove
during the backward and forward movement of the plunger, but passes through

page_text: circular grooves into and out of the extractor groove when the plunger is turned
for locking and unlocking.
The extractor runs in a groove in the body and lies upon the surface of the
plunger; a projection upon the rear end of the extractor fits into a slot in the
plunger and is thus driven backwards and forwards with it, but remains stationary
while the plunger is turning; two projections upon the back of the extractor bear
upon the bottom of the groove in the body until the cartridge is home, when the
hook end rises over the cartridge head and is forced down in front of it by a
spring which is let into the body and bears upon the front lug of extractor when
in this position only.
The hand lever is pivotted to a jointed bracket, which may be folded and fixed
close to body when the gun is not in use, the hand lever at the same time lying
in line with the body and closing the opening underneath.
The cartridges are held in a hopper which is attached to the upper surface of
body; this hopper is kept continually supplied by magazines introduced into the
upper part of it.
When the hopper is removed a shield made of spring steel or other suitable
material is sprung over the fore part of the body and entirely closes all openings.
A breech cap or bolt which screws on the end of the body keeps the whole of
the mechanism in position.
The roller slide with the cam and the helical slot in the plunger give the plunger
an intermittent lateral and rotary motion.
Sheet 2 of the annexed Drawings represents the breech action and other parts
of a machine gun constructed according to this part of my Invention.
Figure 1 is a longitudinal and vertical section.
Figures 2, 3, and 4 are transverse sections taken on the lines 2, 2, 3, 3, and 4, 4,
in Figure 1 respectively.
Figure 5 is an end view.
Figure 6 is a side elevation.
Figure 7 is a portion of a longitudinal section on the line 5, in Figure 2.
Figure 8 is a portion of a longitudinal section on the line 6, 6, in Figure 2.
Figure 9 is a plan with some of the parts removed.
a is the body, and b a portion of the barrel screwed into it; c is the plunger
which slides to and fro in the body as it is impelled by the slide d; a¹, a¹, aro
the guide grooves in the underside of the body in which the slide d works; d¹ is
a roller on the slide which enters a slot in the lever handle e. The handle has
its fulcrum at e¹ and is supported by a guide a²; f, f, are two links jointed to the
side of the body and carrying the fulcrum of the lever handle. These parts which
are also seen in end view at Figure 10 when out of use fold into the positions
shown in dotted lines in Figure 9 and cover the slot in the underside of the body.
d is an inclined projection on the slide d entering a corresponding inclined
groove c¹ on the exterior of the plunger c; c², c², are wings upon the rear end of
the plunger; they are received into longitudinal openings in the upper and lower
parts of the body. These openings communicate at their fore ends with the
recesses a³, a³, into which the wings turn when the plunger rotates, as it is
compelled to do by the inclines d² and c¹ when it cannot move further forward.
Figures 11 and 12 are separate side views of the plunger c. Thus the plunger is
securely locked before the shot can be fired; g is the firing pin contained within
the plunger, and is its spring. These parts are retained by a nut made in two
parts screwed into the rear end of the plunger. The stem of the firing pin is
square in section, and the hole in the nut corresponds in form, so that when the
plunger turns it carries the firing pin round with it; g' is a wing upon the
enlarged rear end of the firing pin; it is received into the groove a of the body,
and at the time of firing it passes into the groove a³, which also contains the
extractor. These grooves are connected by other grooves a and a7; i is a spring
catch within the groove a; it yields and allows the wing g¹ to pass as the plunger

page_text: moves back, but it stops it in coming forward, so that the spring / then becomes
compressed.
The rotary locking motion of the plunger carries the wing g¹ by the cross
groove a into the groove a³; the firing pin then springs forward and strikes the
priming of the cartridge. The unlocking movement of the plunger carries the
wing g back into the groove at
is the extractor; it is lodged in the groove, a³ and is connected with the
plunger by a projection at its rear end entering a recess. This recess in the
plunger is so formed as to leave the plunger free to turn, as already explained,
whilst the extractor remains in its groove; is the extractor spring; it is fixed to
the body a and bears against a projection at the back of the head or hooked end
of the extractor when it is in its forward position. In closing the breech this
spring yields to permit the head of the extractor to pass to the front of the base
flange of the cartridge.
m is a cover on the top of the body; it is held in place by the cap n screwed
on to the rear end of the body; o is a catch on the cover to lock in its place the
cartridge hopper, which is not shown. Cartridges drop down from the hopper into
the trough of the body whenever room is left to receive them by the retirement of
the plunger c.
The parts operate together in the following manner:-The gun having been
fired the lever handle is in its forward position, it is drawn back; and first it
imparts a rotary movement to the plunger. The plunger is unlocked, and it then
retires with its extractor, drawing the cartridge case out of the barrel. At the
end of the backward movement of the plunger the cartridge case is in position to
be thrown out, and the opening in the bottom of the body is here wide enough to
permit of the base flange of the cartridge to pass down through.
The cartridge case is if necessary pushed down by the pusher p, which is a
double ended lever jointed to the cover. The hinder end of the pusher lies in a
groove in the top of the plunger, and this groove is so formed as to depress the
fore end of the pusher at the time when the plunger comes to the end of its course.
The pusher then dips down in front of the face of the plunger and displaces the
cartridge case if it has not already fallen. A fresh cartridge then descends from
the hopper in front of the plunger, and beyond the head of the extractor, and
where the hole in the body is not of a width to permit it to fall through.
On the return movement the plunger drives this cartridge in front of it into the
barrel. In this movement also the wing g' is caught by the spring catch i, the
firing pin g is drawn back within the plunger, and the spring his compressed.
Finally, the plunger is rotated so as to lock it and to pass the wing g' by the
groove a into the extractor groove a³, when the firing pin advances and the shot
is fired.
Having thus described the nature of my said Invention, and the manner of per-
forming the same, I would have it understood that I claim as my improvements
in machine guns and other fire arms,-
First. The breech block divided in two parts, the lower part moveable up and
down in guides and carrying the upper part, this latter being also moveable hori-
zontally and operated by inclines which close it up to and relieve it from the breech
face, substantially as described and illustrated by the Figures on Sheet 1 of the
Drawings.
Second. The combination of the descending breech block and the horizontally
moving loader arranged and operating together, substantially as described and
illustrated by the Figures on Sheet 1 of the Drawings.
Third. The method of feeding the gun from a hopper by causing the handle
which works the breech block, either directly or indirectly, to give motion to
rockers or retaining fingers on the hopper, which then liberate the cartridges singly
and at the proper times and drop them into the gun, substantially as described and
illustrated by the Figures on Sheet 1 of the Drawings.

page_text: Fourth. The machine gun, substantially as described and illustrated by the
Figures on Sheet 1 of the Drawings.
Fifth. The mechanism by which the movement of the lever handle is trans-
mitted to the plunger and caused to take place partly in a longitudinal and partly
in a rotary direction, substantially as described and illustrated by the Figures on
Sheet 2 of the Drawings.
Sixth. The firing mechanism, including the firing pin, caused to partake of the
rotary movement of the plunger, retained by a catch as the plunger moves forward
and released by the rotary movement, substantially as described and illustrated
by the Figures on Sheet 2 of the Drawings.
Seventh. The hand lever and its bracket or support, folding, when out of use,
close against the body, substantially as described and illustrated by the Figures on
Sheet 2 of the Drawings..
Eighth. The arrangement of the extractor and its spring, the spring being fixed
upon the body and pressing the head of the extractor forwards over the base flange
of the cartridge when the same is in the barrel, substantially as described and
illustrated by the Figures on Sheet 2 of the Drawings.
Ninth. The machine gun, substantially as described and illustrated by the Figures
on Sheet 2 of the Drawings.
In witness whereof, I, the said Thorsten Nordenfelt, have hereunto set my
hand and seal, this Thirty first day of December, in the year of our Lord
One thousand eight hundred and eighty one.
THORSTEN NORDENFELT. (L.S.)