Improvements in Apparatus for Working Ordnance.
Year: 1888

page_text: Date of Application, 4th Sept., 1888
Complete Specification Left, 4th June, 1889-Accepted, 6th July, 1889
DDAVTO
TA
SDRAI
TATIAN
CIONAL SP
PRO
ALATIAN
Improvements in Apparatus for Working Ordnance.
I, THORSTEN NORDENFELT, of 53 Parliament Street Westminster, Civil Engineer,
do hereby declare the nature of this invention to be as follows :-
The object of the invention is a mounting for automatic opening and closing of the
breech and extracting of the cartridge in guns of considerable calibre.
The breech mechanism and mounting of the gun are so arranged that the recoil of
the gun causes the breech to be opened and extracts the cartridge case, and stores up
power for closing the breech after a fresh cartridge has been entered into the
chamber.
For the breech mechanism I use an interrupted screw and the mechanism is so
arranged that by one turning motion the breech block is first disengaged from the
screw in the gun then withdrawn from the breech and finally is turned around an axis
parallel to the bore of the gun, whereby the block is moved to the side leaving the
breech open.
I provide gear teeth upon the block and place a pinion on the axis, about which the
block turns when it is moved to the side to clear the bore. This pinion engages with
the teeth in the block. I further mount a bar parallel to the gun, and at the end of
this bar is fixed another pinion, which engages with the pinion on the axis.
Round the bar is placed a tube or sleeve which can turn freely upon it. The sleeve
is provided with a clutch which in one direction engages the pinion at the end of the
bar but in the other direction allows the sleeve to be turned independent of the bar.
The sleeve and bar move together longitudinally when the gun recoils.
The bar and sleeve pass through a bearing on the gun and through another bearing
on the cradle or part of the mounting which always remains parallel with the gun, but
does not recoil with the same. Finally I put a collar on the bar which rotates with it
but which does not move longitudinally.
0
The above mentioned bearing on the mounting is provided with a stud, entering a
corresponding groove in the sleeve, or otherwise so arranged that when the gun
recoils and carries with it the bar and sleeve, the sleeve is made to turn in one
direction when the gun recoils, and in the opposite direction when the gun returns to
its firing position.
The collar which turns with the bar but which does not move longitudinally,
I form as a fusee and attach a spring to the same.
These parts act in the following way:
When the gun recoils it carries the mechanism with it (except as previously stated)
and the sleeve is turned but the clutch being disengaged the mechanism is not
actuated.
When the gun is moved again to firing position by the springs or buffers in the
recoil mounting the sleeve is turned in the opposite direction; the clutch now
engages with the cog wheel at the end of the bar, turns the same, and through the
pinion on the axis turns the block so as to disengage it from the teeth in the breech,
afterwards to withdraw it, and finally to pivot it round the axis leaving the bore free.
When the cog wheel and the bar are turned, the collar to which the spring is
attached is turned, and the spring is put in tension. In the breech of the gun I place
a small ejector. When the breech block pivots round the axis parallel with the gun,
a part in connection with it strikes the ejector and causes it to operate to throw out
the cartridge. A bolt prevents the block returning until it is withdrawn. This is
done when a fresh cartridge is entered into the bore; the rim of the same presses
against the ejector and this in its movement displaces the bolt and allows the breech
to be closed. The block being released the spring turns the bar and pinion and
thereby operates the mechanism,

page_text: I so arrange the parts that the breech block can be disengaged to allow it to be
operated by hand.
Dated this 4th day of Candau 1000
COMPLETE SPECIFICATION.
Improvements in Apparatus for Working Ordnance.
I, THORSTEN NORDENFELT, of 53 Parliament Street, 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:
This invention has for its object apparatus applicable to guns of considerable calibre
and which automatically opens and closes the breech and extracts the cartridge case.
The breech of the gun is closed by a breech block which enters into it and is
secured by a divided screw thread so that by a partial turn it can be locked or
unlocked.
The breech block is embraced by a ring or holder in which it is able to turn and
the ring or holder can turn about a stud or axis fixed to the breech of the gun
and parallel to the bore.
There is a pin in the ring or holder which enters a helicoidal groove in the breech
block. This groove is so formed that in opening the breech it first allows the
breech block to be freely turned sufficiently far to disengage the screw threads and
then it still allows the block to be turned but only in conjunction with a rearward
movement which takes the breech block out of the gun.
Afterwards by the movement of the ring or holder about the stud or axis on
which it is mounted the breech block is carried to one side to leave the bore 'clear'
to receive the cartridge.
The opening and closing of the breech is performed automatically and for this
purpose a pinion is provided upon the stud. The pinion is in gear with an arc of
teeth upon the breech block.
In opening the breech the pinion in revolving turns the breech block in the ring
or holder as far as the groove and pin admit; that is to say until the block is
unlocked and withdrawn. Then the pinion still rotating carries the breech block
and also the ring or holder with it in a circuit around the stud and so the breech
of the gun is left free for the insertion of a cartridge.
The pinion is driven by a wheel mounted on the gun and connected by its axis
with the cradle so that during recoil the axis does not rotate, but when the gun
moves forward again the axis turns and operates the breech mechanism to open
the breech. The same rotation of the axis winds up a spring which when the gun
is loaded is allowed to react and the mechanism then operates to close the breech.
The arrangement which I prefer for imparting movement to this driving axis is as
follows:-
The axis which is parallel to the bore of the gun is carried by the gun in a
bearing near its breech end and it passes with groove and feather through a sleeve
which is held in a box upon the cradle. A coiled spring surrounding the sleeve
is attached to it by one end and the other end is fast to the box. In the axis a
spiral groove is formed and there is a spring pin upon the box to enter. the groove.
When the gun is in the firing position the pin is not in the groove and during
the recoil the pin has no influence and the axis does not revolve. But when the
gun has recoiled to its full extent or nearly so the pin drops into the groove and
hence when the gun comes forward again (which it immediately. does in consequence
of the reaction of the springs in the hydraulic control cylinders) the axis is caused
to rotate by the pin following along the spiral groove. Thus the spring coiled around
the sleeve on the axis is wound up. The same rotation of the axis causes the with-
drawal of the breech block and opens the breech as already stated. At the end of the
forward movement of the gun the spring pin upon the cradle runs out of the spiral

page_text: Figure 1 is a side elevation of the gun and automatic loading mechanism; it is
shown upon a mounting which forms the subject of another Patent No. 1606 in the
year 1889.
Figure 2 is a plan. Figure 3 is a longitudinal section and Figure 4 is a rear
elevation. Figure 5 is another side elevation, in this figure the shield is partly in
section and many parts not shown in Figure 1 are here indicated by dotted lines.
Figure 6 shows full size the spring stop by which the breech is held open until
released by the insertion of a cartridge.
Figure 7 shows a longitudinal section of a separated portion of the mechanism―
Figures 8 and 9 are end elevations of these parts.
a is the base of the mounting. the upper frame which can rotate thereon. c is
the cradle carried by its trunnions in bearings on the upper frame. e is the gun held.
in the cradle and moveable longitudinally in it. The elevating and training
mechanism is shown but as it forms no part of the present invention it is unnecessary
here to explain it in detail. are hydraulic recoil cylinders; there are coiled springs
(not shown) confined within them, which after recoil return the gun to the firing
position. These springs may be replaced by springs of other forms or by compressed
air. is the breech block, it is able to turn in the ring m. The breech plug is locked
in the gun by a divided screw and it has a helicoidal groove in it with which a pin
within the ring m engages. These arrangements being now well known are not
represented in the drawings; they are fully described in my Specification No. 5743
in the year 1888 and are such that the breech block being in its place in the gun, its
rotation causes first the unlocking of the screw and then its rearward movement out
of the gun. The breech block has upon it a ring of teeth and it is provided with a
telescopic handle 2: The handle is jointed to the block at so that the handle may
be made to project from the block on either side. In automatic firing no use is made
of this handle. n is an axis carried in the bearing n¹ fixed to the gun. This axis
slides through a bearing upon the cradle and through a sleeve o contained in a spring
box attached to the cradle. p is a coiled spring attached by one end to the spring
box and by the other to the sleeve. The sleeve turns with the axis. n' is a spiral

page_text: m is
groove in the axis n.
qis a spring pin carried by an arm o¹ projecting rearwards
from the spring box. The pin q tends inwards and drops into the groove n² when
g
this groove passes beneath it; this takes place towards the end of the recoil. The
pin passes out at the rear end of the groove as the gun reaches its forward position.
The axis consequently is turned as the gun runs forward but not during the recoil,
this rotation winds up the spring p.
is a toothed wheel on axis n. n³× is a bolt
carried by the axis it shoots into a hole in the wheel or rather in a die capable of
moving along a curved concentric slot in the wheel but held central therein between
two stiff coiled springs. This bolt is withdrawn when the gun is to be worked by
hand and it then shoots into a hole formed to receive it on the outside of the
bearing n. s¹ is a long pinion mounted on a stud s fixed into the gun parallel to the
axis. The pinion s gears with the wheel and also with the teeth upon the breech
block. Inclined teeth are employed as the drawing indicates. The ring
mounted on the studs and can turn about it. As the gun runs forward the breech
block turns in the direction indicated by the arrow in Figure 4; it turns in this
direction as far as the stop in the ring allows it to do so and until it is out of the
gun; the ring m carrying the breech block in it then moves around the studs until
it comes to rest against the abutment t. The ring m is provided with a handle m¹
which may be used for moving it when working by hand. u in Figure 6 is a stop
having its fulcrum at ¹, it is mounted upon the breech of the
gun being recessed into
the face against which the ring m works. u² is a piston and u³ a spring which presses
the stop outwards. When the ring m comes against the abutment t, the stop u starts
out in front of the ring and prevents its return. vis another lever movable about a
fulcrum at v¹. w is the cartridge in its place in the gun. On the insertion of the
cartridge the base flange comes against the end of the lever and moves it to the
position in which it is shown by full lines in the Figure. The other end of the lever v
bears against the adjacent end of the lever u and so this lever also is by the insertion of
the cartridge forced against the resistance of the spring u³ into the position indicated
by full lines, in this position it no longer retains the ring m and so the breech closes
by the reaction of the spring.p. When the breech opens the levers u and v assume
the positions indicated by dotted lines and the lever v aids in ejecting the cartridge
case from the gun. When working the gun by hand the levers u and are put out
of use by pressing the lever v forward into the recess v² in which it is then retained
by the light spring v³.
The mechanisin which I have described admits of variation, thus for example a
fixed driving pin q may be substituted for the spring pin shown by the drawings; in
this case the pin would remain constantly engaged in the groove n² and this groove
would be formed, not in the axis n itself, but in a sleeve surrounding it and turning
freely on the axis when the gun recoils but clutched with it and the toothed wheel
which it carries whilst the gun advances to the firing position.
The arrangement shown by the drawings in which the driving pin 9 serves also as
the clutch to engage and disengage the parts as required, is however to be preferred.
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. The combination consisting of the gun; the breech block locked in the gun by a
divided screw thread; also springs which move the gun forward after recoil; and
mechanism put in action by the gun during its forward motion after recoil; which
mechanism then rotates the breech block and opens the breech.
2. The combination consisting of the gun; the breech block; springs which move
the gun forward; mechanism which then rotates the breech block; and a spring
which is then wound up, and when released causes the closing of the breech.
3. The combination consisting of the cradle d; the gun e; the breech block 1; the
teeth; the ring m ; the stud s; the pinion s¹; the axis n; the wheel r; and
mechanism which rotates the axis n when the gun moves forward in the cradle.
4. The combination consisting of the cradle d; the gun e; the breech block ; the

page_text: teeth, the ring m; the stud s; the pinion s¹; the axis n; the wheel r ; mechanism
which rotates the axis n when the gun moves forward; the coiled spring p which is
thereby wound and which when liberated rotates the axis n in such manner as to close
the breech.
a
5. The method substantially as described of closing the breech of a gun; by
spring which is constrained by the forward movement of the gun and is released by
the insertion of the cartridge.
T
1030
THN. NORDENFELT.