Year: 1887

page_text: Date of Application, 17th May, 1887
Complete Left, 16th Feb., 1888
Complete Accepted, 16th Mar., 1888
1, THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster Civil
Engineer do hereby declare the nature of this invention to he as follows:-
This invention relates to breech loading guns in which the breech is closed by a
block entering the breech opening and having spaced screw threads upon it engaging
with corresponding spaced screw threads within the breech of the gun. In such guns
give all the necessary movements to the breech block by means of a lever handle
and axis rotating through the arc of a circle. The same movement also actuates an
extractor and gives the necessary movement to it for withdrawing the cartridge case
from the chamber of the gun.
The mechanism as I prefer to construct it is as follows:-
Upon the breech end of the gun a flanged ring or cap is fixed, and this has upon it
bearings in which a vertical axis, formed with or fixed to the lever handle, is able to
turn. This axis is on one side of and a short distance in rear of the breech opening-An
arm at the upper end of this axis carries a stud or roller to engage with a notch in a
sliding bar which is carried in guides and moves transversely to the bore of the gun.
The same bar has another notch in it and this engages with a stud or roller upon the
breech block. These parts are so arranged that in the movement of the lever handle
to open the breech, the bar, during the first part of the movement, slides in its guides,
and in doing so turns the breech-block through an angle of about 60 degrees or
sufficiently far to disengage the screw threads upon it from the corresponding screw
threads within the gun. When this has taken place the stud or roller, which is
carried with the lever handle, escapes from its notch in the transverse horizontal bar
and travels on, whilst the bar remains without further movement.
Upon the rear end of the breech-block there is a collar in which it is able to turn
freely, and this collar has a stud upon it projecting downwards through a longitudinal

page_text: slot in a tray or support provided to receive the breech block when withdrawn and
into another slot formed in an arm by which the withdrawal of the breech block from
the gun and its replacement after loading are effected. This arm I shall call the
withdrawing arm. The withdrawing arm and also the tray are mounted upon the
axis of the lever handle, but they are not fast thereon, and both these parts remain
stationary during that portion of the movement of the handle which causes the
engagement and disengagement of the screw threads, as already described.
In opening the breech, as soon as the lever handle is moved sufficiently far to
disengage the screw threads, a shoulder upon or moving with the lever handle comes
against another shoulder upon the withdrawing arm and this then commences to turn
with the hand lever moving rearwards from the breech of the gun. In this movement
it draws back the breech-block out of the gun, the breech block being engaged with
the disengaging arm in the manner already described. In this way the breech block
is landed upon the tray or support and as soon as this is the case, the tray or support
also commences to move round with the lever handle carrying the breech block to the
rear and at the same time conveying it to one side so as to leave the breech opening
unobstructed. In closing the breech the same movements take place in reversed
order First all the parts move together whilst the breech block is brought back into
position to enter the breech opening, then the tray or support remains stationary
whilst the breech block is thrust from off it by the withdrawing arm and finally this
arm remains at rest during the last part of the movement of the lever handle, whilst
the rotary movement is imparted to the breech block requisite to cause the engagement
of the screw threads.
on
In order to ensure this sequence of movements a bolt or filling piece is provided
the withdrawing arm and a piece fast with the axis of the lever handle gives motion
to the bolt. It has a stud upon it and this in opening the breech whilst the unlocking
movement is in progress enters an inclined groove in the bolt. The bolt thus
moved along the arm inwards towards the axis whilst the shoulder on the axis of
the lever handle is moving towards the corresponding shoulder on the withdrawing
arm. The bolt is thus drawn inwards behind the first mentioned shoulder, and by the
time that this comes in contact with the shoulder upon the withdrawing arm the space
behind it becomes occupied by the bolt and then for the time the withdrawing arm
is fast locked on the axis of the lever handle. The bolt or filling piece is not with-.
drawn until in closing the breech the breech block has been again inserted into the
breech opening.
The extractor, which is provided to withdraw the cartridge case from the chamber
of the gun after firing, slides in a longitudinal groove provided for it on one side
of the breech opening. It has a lip which, when the cartridge is in place in the
gun, overlaps the flange at the base of the cartridge. It has also part of a screw
thread formed upon it at the side. When the breech block is turned to open the
breech the thread upon the breech block engages with the thread upon the extractor,
and the screw then operates powerfully upon the extractor to withdraw it a short
distance and loosen the cartridge case in the bore. When the breech block being
unlocked is drawn rearwards, in the way already described (the screw thread upon
it being still engaged with that upon the extractor) the extractor also is drawn back
carrying the cartridge case with it. As soon as the breech block has been landed
upon its cradle or support and this commences to move around the centre, the screw
thread upon the breech block leaves the screw thread on the extractor, and the extractor
remains at rest at the rear end of its guide groove. The extractor also is then locked
by a sliding bolt which enters a recess in the side of the extractor and holds it in
place this bolt is carried in guides upon the cap on the breech of the gun and it
receives its movement from a lug which is fast with the axis of the lever handle.
The face of the breech block is cupped to a form corresponding to that of the base
of the cartridge that is to say somewhat inclined at the sides and in loading this cavity
effects the centering of the cartridge and ensures it entering truly into the gun
although there may be but little clearance between the flange of the cartridge and
the screw threads in the breech of the gun over which the flange has to pass,

page_text: The way the parts operate is as follows:-in loading the cartridge is first inserted
into the bore as far as the extractor will permit it to enter, then the breech block
swings round and the cavity in its face applies itself over the base of the cartridge
whilst it is stopped by the extractor from moving forward. The base of the cartridge
is thus compelled to enter to the bottom of the cavity of the breech block.
In the further movement of the parts the extractor becomes locked with the breech
block and these parts between them then carry the cartridge forward into the gun
with the cartridge securely held and truly centered between them.
My invention it will be seen is well suited to be applied to existing guns in which
the breech is closed by a breech block locked in place by means of divided screw
threads.

page_text: 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:-
This invention relates to breech loading guns in which the breech is closed by a
block entering the breech opening and having spaced screw threads upon it engaging
with corresponding spaced screw threads within the breech of the gun. In such guns
I give all the necessary movements to the breech block by means of a lever handle
and axis rotating through the arc of a circle. The same movement also actuates an
extractor and gives the necessary movement to it for withdrawing the cartridge case
from the chamber of the gun.
The mechanism as I prefer to construct it is represented by the annexed
drawings.
Figure 1 is a rear elevation.
Figure 2 is a longitudinal section mainly on the line A B in Figure 1 but in part
(around the extractor n) on the line G H in the same figure.
Figure 3 is a plan.
Figure 4 is a section on the line CD in Figure 2.
Figure 5 is an elevation of the lever handle, its axis and other parts. (A portion of
the axis is broken out).
Figure 6 is a section on the line E F in Figure 5.
Figure 7 is a plan of the lever handle and parts connected with it.
Figures 8 show the extractor.
Figures 9 show the bolt which serves to retain the extractor when the breech is
open.
Upon the breech end of the gun a flanged ring or cap a is fixed, and this has upon
it bearings a' a' in which a vertical axis b formed with or fixed to the lever handle c
is able to turn. This axis is on one side of and a short distance in rear of the breech
opening. An arm d at the upper end of this axis carries a stud or roller d¹ to engage
with a notch e¹ in a sliding bar e which is carried in guides and moves transversely to
the hore of the gun. The same bar has another notch e in it and this engages with a
stud or roller upon the breech block f. These parts are so arranged that in the
movement of the lever handle c to open the breech the bar e during the first part of
the movement slides in its guides and in doing so turns the breech block through an
angle of about 60 degrees or sufficiently far to disengage the screw threads upon it
from the corresponding screw threads within the gun. When this has taken place the
stud or roller d which is carried with the lever handle escapes from its notch in the
transverse horizontal bar e and travels on whilst the bar remains without further
movement.

page_text: The bar e is now held in position at the end of its course by an arc g on the axis b
which then comes in behind the curved end of the bar at e³.
Upon the rear end of the breech block f there is a collar h in which it is able to
turn freely and this collar has a stud upon it projecting downwards through a
longitudinal slot in a tray or support i provided to receive the breech block when
withdrawn and into another slot k¹ formed in an arm by which the withdrawal of
the breech block from the gun and its replacement after loading are effected. This
arm I shall call the withdrawing arm. The withdrawing arm k and also the tray i
are mounted upon the axis b of the lover handle, but they are not fast thereon, and
both these parts remain stationary during that portion of the movement of the handle
which causes the engagement and disengagement of the screw threads, as already
described.
In opening the breech as soon as the lever handle c is moved sufficiently far to
disengage the screw threads f² a shoulder upon a piece moving with the lever.
handle comes against another shoulder upon the withdrawing arm and this then
commences to turn with the hand lever moving rearwards from the breech of the gun.
In this movement it draws back the breech block fout of the gun the breech block
being engaged with the disengaging arm in the manner already described. In this
way the breech block is landed upon the tray or support and as soon as this is the
case the tray or support also commences to move round with the lever handle carrying
the breech block to the rear and at the same time conveying it to one side so as to
leave the breech opening unobstructed. In closing the breech the same movements
take place in reversed order. First all the parts move together whilst the breech
block is brought back into position to enter the breech opening, then the tray or
support remains stationary whilst the breech block f is thrust from off it by the
withdrawing arm k and finally this arm remains at rest during the last part of the
movement of the lever handle, whilst the rotary movement is imparted to the breech
block requisite to cause the engagement of the screw threads.
In order to ensure this sequence of movements a bolt or filling piece m is provided
on the withdrawing arm and a piece fast with the axis of the lever handle gives
motion to the bolt. It has a stud upon it and this in opening the breech whilst the
unlocking movement is in progress enters an inclined groove m¹ in the bolt. The bolt
is thus whilst the stud 12 passes from 1× to 1** moved along the armik inwards towards
the axis whilst the shoulder on the axis of the lever handle is moving towards the
corresponding shoulder on the withdrawing arm. The bolt is thus drawn inwards
behind the first mentioned shoulder, and by the time that this comes in contact with
the shoulder upon the withdrawing arm the space behind it becomes occupied by the
bolt in and then for the time the withdrawing arm is fast locked on the axis of the
lever handle. The bolt or filling piece m is not withdrawn until in closing the breech
the breech block has been again inserted into the breech opening.
The extractor n which is provided to withdraw the cartridge case from the chamber
of the gun after firing, slides in a longitudinal groove o provided for it on one side of
the breech opening. It has a lip n which when the cartridge p is in place in the gun,
overlaps the flange at the base of the cartridge. It has also part of a screw thread n³
formed upon it at the side. When the breech block is turned to open the breech
the thread f upon the breech block engages with the thread n' upon the extractor,
and the screw then operates powerfully upon the extractor to withdraw it a short
distance and loosen the cartridge case in the bore. When the breech block being.
unlocked is drawn rearwards, in the way already described (the screw thread f* upon
it being still engaged with that upon the extractor) the extractor also is drawn back
carrying the cartridge case with it. As soon as the breech block has been landed
upon its cradle or support and this commences to move around the centre b the screw
thread upon the breech block leaves the screw thread n² on the extractor, and the
extractor remains at rest at the rear end of its guide groove o. The extractor also is
then locked by a sliding bolt q which enters a recess n³ in the side of the extractor
and holds it in place this bolt is carried in guides a* a* upon the cap a on the

page_text: breech of the gun and it receives its movement from a cam r which is fast with the
axis of the lever handle.
:
q¹ is a stud on the bolt q (see Figs. 9) which remains constantly engaged in the cam
groove and this groove is so formed as to shoot the bolt forward into the recess n³
and to withdraw it at the proper times.
3
The face of the breech block is cupped to a form corresponding to that of the
base of the cartridge p that is to say somewhat inclined at the sides and in loading
this cavity f³ effects the centering of the cartridge and ensures it entering truly into
the gun although there may be but little clearance between the flange of the cartridge
and the screw threads in the breech of the gun over which the flange has to
pass.
The way the parts operate is as follows :—in loading the cartridge p is first inserted
into the bore as far as the extractor n will permit it to enter, then the breech block f
swings round and the cavity f³ in its face applies itself over the base of the cartridge p
whilst it is stopped by the extractor n from moving forward. The base of the
cartridge is thus compelled to enter to the bottom of the cavity f³ of the breech
block.
In the further movement of the parts the extractor n becomes locked with the
breech block and these parts between them then carry the cartridge forward into
the gun
with the cartridge securely held and truly centred between them.
My invention it will be seen is well suited to be applied to existing guns in which
the breech is closed by a breech block locked in place by means of divided screw
threads.
The parts and h fit together with a bayonet joint; there are lugs on the part f
which enter through corresponding notches in the part h. The lugs and notches
extend over arcs of 90 degrees and as the rotary movement of the breech block fis
but 60 degrees the parts remain engaged when at work.
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. Breech mechanism in which an axis b by means of an arm d turns the breech
block and locks and unlocks it and by means of another arm k withdraws and
replaces the breech block; the said arm k being so connected with the axis b as to
move with it only over a portion of the are over which the rotation of the axis
extends.
2. The combination of the parts a b c d e f hi and k substantially as described.
3. The combination of the axis 6; the part with its shoulder ; the withdrawing
arm k; and the filling piece m operating substantially as described.
4. The extractor n with its screw threads n' engaging with the screw threads f³ on
the breech block and disengaging therefrom substantially as described.
5. The combination of the extractor n the bolt q and a cam or its equivalent on the
axis 6 operating the bolt substantially as described.
6. The combination of the block with its cup like face f³ and the extractor n¹ in
such manner that when loading the parts fand n' lock together and hold the base of
the cartridge centrally between them and then advance with it into the gun substantially
as described.
7. Breech loading mechanism substantially as described and represented by the
annexed drawings.
Dated this 16th day of how 1000