Year: 1887

page_text: Date of Application, 9th June, 1887
Complete Left, 9th Mar., 1888
Complete Accepted, 27th Apr., 1888
I, 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:-
:-
This invention has for its object improvements in breech loading guns.
In order to receive the breech block the walls of the gun immediately in rear of the
breech face, are cut away on one side in such manner as to form a vertical face parallel
to the axis and tangential to the boro or thereabout. In this vertical face there is an
opening into a lateral passage communicating with the bore and of its full diameter.
The breech block fits to the gun making up a complete although divided cylinder in
rear of the breech face. The two parts are provided with a series of parallel inter-
locking grooves and ridges both on the otherwise plain lateral faces which abut the
one on the other and on the curved surfaces corresponding to the inner side of the
original bore. Thus there is a large area of bearing surfaces on all sides of the bore
to resist the rearward pressure upon the breech block when the gun is discharged.
The way in which it is preferred to mount and operate this breech block is as
follows:-
A ring is shrunk upon the gun immediately in front of the breech-face and this
ring carries a stationary vertical spindle upon which the breech block is hung by means
of short arms. The arms are moveable about the spindle in such manner that in
opening the breech the breech block may first move a short distance laterally (sufficient
to disengage the interlocking parts) and then swing round about the spindle, leaving
the bore of the gun open. The spindle is made cylindrical except that it is flattened
at the front and back where the arms of the breech block embrace it. The holes
in the arms to receive the spindle are of a key-hole-like form, with straight
sides which fit over the flats on the spindle when the breech-block is home.
When in opening the breech the breech-block is moved laterally to disengage the
interlocking parts the spindle is thereby brought into the enlarged or circular portion
of the holes in the arms, and the breech block is set free to turn about the spindle. A
lever handle is also provided to turn about the spindle; it has a short arm upon it
carrying a small roller which is received into a cam groove on the under side of the
lower arm of the breech block. When in opening the breech the lever handle is
moved, the roller travelling along the cam groove first imparts to the breech-block the

page_text: necessary lateral movement and then, when the breech-block is free, the further
movement of the lever and arm carries the breech-block round about the spindle.
Similarly in closing the breech the arm connected with the lever handle carries the
breach-block round with it until it is brought up to the breech face, and then the roller
upon the arm travels along the cam groove and moves the breech-block laterally to
the extent requisite to engage the interlocking parts.
This breech closing mechanism is especially suitable for quick firing guns in which
the charge is contained in a metallic capsule which after firing, requires to be with-
drawn from the bore. I therefore provide extractors consisting of two horizontal blades
let into grooves in the breech face, one above and the other below the bore. The
cartridge, when in its place, rests against these blades in recesses formed in them at the
back to receive the base flange.
The extractor blades are connected with the breech block by a vertical joint pin at a
short distance from the main spindle. When the breech is opened the extractor blades
after being first drawn a distance laterally are slowly moved rearwards at one end,
whilst the other or inner end remains in the groove in the breech face. At this time
the extractors act slowly and powerfully to loosen the cartridge case in the boro whilst
the breech block turns for some distance about the spindle. Afterwards shoulders upon
the extractor blades come against stops upon the arms of the breech block, and
then the extractor blades move round the spindle with the breech block and the
cartridge case is projected rapidly to the rear.
In order to fire the charge various arrangements of firing mechanism either
mechanical or electrical may be einployed. When mechanical mechanism is resorted
to I prefer the following:
:-
The cartridge carries its priming in the centre of its base and the breech-block
contains a firing pin and a coiled spring serving to force the firing pin forward when
it is released. The firing pin has a finger upon it projecting downwards and extending
through the breech block on its under side. This finger is received into a corresponding
groove in the part of the gun beneath the breech-block, so that the finger does not
interfere with the movement of the breech-block in opening the breech, but in closing
the breech the finger comes against a shoulder in the groove in the gun and is retained
by it, whilst the further movement of the breech-block causes the spring behind the
firing pin to be compressed. The passage in the breech block in which the firing pin
works also has a cam-like groove cut in it and a stud upon the firing pin enters this
groove. When the firing pin is caused to recede along the passage in the breech-
block it is when the spring is sufficiently compressed, turned through a small anglo
by the operation of the cam groove and this is sufficient to disengage the finger on the
firing pin from the shoulder in the groove upon the gun. The firing pin however does
not immediately advance in the breech-block because the stud upon it now comes
against another shoulder which is formed in the groovo in which the stud works, and
so the firing pin is retained until it is required to fire the charge.
The firing is effected by a trigger upon the gun which operates against the finger
on the firing pin so as to turn it and release its stud from the retaining shoulder. The
trigger cannot operate until the breech is securely closed, because it cannot advance
until a recess in the breech block comes into position to receive it.
Dated this 8th day of June 1887.

page_text: 1, 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 has for its object improvements in breech loading guns.
In order to receive the breech block the walls of the gun immediately in rear of the
breech face are cut away on one side in such manner as to form a vertical face parallel
to the axis and tangential to the bore or thereabout. In this vertical face there is an
opening into a lateral passage communicating with the bore and of its full diameter.
The breech block fits to the gun making up a complete although divided cylinder in
rear of the breech face. The two parts are provided with a series of parallel inter-
locking grooves and ridges both on the otherwise plain laterai faces which abut the
one on the other and on the curved surfaces corresponding to the inner side of the
original bore. Thus there is a large area of bearing surfaces on all sides of the bore
to resist the rearward pressure upon the breech block when the gun is discharged.
The way in which it is preferred to mount and operate this breech block is as
follows:
A ring is shrunk upon the gun immediately in front of the breech-face and this
ring carries a stationary vertical spindle upon which the breech block is hung by
means of short arms. The arms are movable. about the spindle in such manner
that in opening the breech the breech block may first move a short distance
laterally (sufficient to disengage the interlocking parts) and then swing round
about the spindle, leaving the bore of the gun open. The spindle is made cylindrical
except that it is flattened at the front and back where the arms of the breech block
embrace it. The holes in the arms to receive the spindle are of a key-hole-like
form, with straight sides which fit over the flats on the spindle when the breech-block
is home.
When in opening the breech the breech-block is moved laterally to disengage the
interlocking parts the spindle is thereby brought into the enlarged or circular portion
of the holes in the arms, and the breech block is set free to turn about the spindle.
A lever handle is also provided to turn about the spindle; it has a short arm upon it
carrying a small roller which is received into a cam groove on the under side of
the lower arm of the breech block. When in opening the breech the lever handle
is moved, the roller travelling along the cam groove first imparts to the breech-
block the necessary lateral movement and then, when the breech-block is free,
the further movement of the lever and arm carries the breech-block round
about the spindle. Similarly in closing the breech the arm connected with the
lever handle carries the breech-block round with it until it is brought up to
the breech face, and then the roller upon the arm travels along the cam groove
and moves the breech-block laterally to the extent requisite to engage the inter-
locking parts..

page_text: This breech closing mechanism is especially suitable for quick firing guns in which
the charge is contained in a metallic capsule which after firing, requires to be with-
drawn from the bore. I therefore provide extractors consisting of two horizontal blades
let into grooves in the breech face, one above and the other below the bore. The
cartridge, when in its place, rests against these blades in recesses formed in them at the
back to receive the base flange.
The extractor blades are connected with the breech block by a vertical joint pin at
a short distance from the main spindle. When the breech is opened the extractor
blades after being first drawn a distance laterally are slowly moved rearwards at one
end, whilst the other or inner end remains in the groove in the breech face. At this
time the extractors act slowly and powerfully to loosen the cartridge case in the bore
whilst the breech block turns for some distance about the spindle. Afterwards shoulders
upon the extractor blades come against stops upon the arms of the breech block, and
then the extractor blades move round the spindle with the breech block and the cartridge
case is projected rapidly to the rear.
. In order to fire the charge various arrangements of firing mechanism either
mechanical or electrical may be employed. When mechanical mechanism is resorted
to I prefer the following:
:-
The cartridge carries its priming in the centre of its base and the breech-block
contains a firing pin and a coiled spring serving to force the firing pin forward
when it is released. The firing pin has a finger upon it projecting downwards and
extending through the breech block on its under side. This finger is received into a
corresponding groove in the part of the gun beneath the breech-block, so that the
finger does not interfere with the movement of the breech-block in opening the breech,
but in closing the breech the finger comes against a shoulder in the groove in the gun
and is retained by it, whilst the further movement of the breech-block causes the spring
behind the firing pin to be compressed. The passage in the breech block in which the
firing pin works also has a cam-like groove cut in it and a stud upon the firing pin
enters this groove. When the firing pin is caused to recede along the passage in the
breech block it is when the spring is sufficiently compressed, turned through a small
angle by the operation of the cam groove and this is sufficient to disengage the finger
on the firing pin from the shoulder in the groove upon the gun. The firing pin
however does not immediately advance in the breech-block because the stud upon
it now comes against another shoulder which is formed in the groove in which
the stud works, and so the firing pin is retained until it is required to fire the
charge.
The firing is effected by a trigger upon the gun which operates against the finger on
the firing pin so as to turn it and release its stud from the retaining shoulder. The
trigger cannot operate until the breech is securely closed because it cannot advance
until a recess in the breech block comes into position to receive it.
In order that my said invention may be more fully understood and readily carried
into effect I will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation
Figure 2 is a rear elevation and
Figure 3 is a plan of a gun constructed according to this invention. In these figures
the breech is shown closed.
Figure 4 is a plan with the breech open the portion of the gun to the rear of the
bore being shown in section on a horizontal plane along the axis of the bore.
A is the gun and a is the portion of it to the rear of the bore. is the breech
block which as is shown has à plane face top and bottom and a curved face at the
centre to fit the corresponding faces of the part a. The two parts a and b are provided
withta series of parallel interlocking grooves and ridoes a¹ a¹ and b¹¹ on their curved

page_text: (shown separately in elevation and cross-section at Figures 5) upon which the breech
block bis hung. This spindle d is carried by a lug c (see Figure 1) on the ring c
above and below the lug c' tho spindle d is flattened at the front and rear. The holes
in the arms carrying the breech block are of a key hole like form the straight sides
fitting over the flats on the spindle when the breech block is home and the circular
part fitting the circle of the spindle when the interlocking parts a¹ b¹ and a² b² have
been disengaged so that the breech block is then free to turn upon the spindle.
e is a lever handle for opening the breech, it is pivotted on the upper part of the
spindled and carries a pin e' working in a cam slot e2 cut in the breech block. The
front part of this slot is radial or nearly so to the axis of the handle so that the handle
can gain momentum before any work has to be done. The pin e¹ however in the latter
part of its course presses against the straight part of the side of the slot e² and thereby
moves the breech block transversely to the axis of the gun until the locking
parts aand 22 have been disengaged. When this has been done the pin e
comes to the end of the slot e and the further motion of the lever handle turns the
breech block about the spindle d as shown in Figure 4.
ff are the extractors these are shown in dotted lines at Figure 2 and one of them
in full lines at Figure 6 the latter figure being a longitudinal horizontal section on the
line XX figure 2. these extractors are pivotted by a pin f₁ to the breech block. As
the latter is turned their pivotted ends slowly come away from the breech of the gun
the other ends however moving transversely to the bore. This movement starts the
cartridge and continues until the shoulders f² on the breech block come against the
extractors when this takes places the extractors commence to revolve with the breech
block and the cartridge is thrown out. Inclined slots f³ ³ are provided in the part a
of the gun as shown by dotted lines in Figure 6 so as to bring the extractors back to
the position shown in that Figure.
Figures 7 and 8 are transverse sections of the breech block on the lines Y Y and Z Z
Figure 2 illustrating the firing mechanism.
g is the firing pin which is enlarged at its middle where it works in the tube or
cylinder h. This cylinder is pressed forward by a coiled spring j. The firing pin g is
pressed backwards by another coiled spring at the front end of the cylinder h. In
the act of firing the pin g having been forced forward by the spring ; and having thus
acquired momentum compresses the spring and assumes the position shown in
Figure 7 firing the cartridge; the spring & then brings the firing pin g back again
sliding it within the tube and withdrawing its protruding end into the breech block.
The firing pin y has a finger g¹ (see Figures 2 and 8) upon its underside. This finger
fits in a cam recess in the breech block the shape of which is shown in Figure 8. In
closing the breech the end of the finger g¹ comes against an incline 1 (see Figure 4) at
the rear of the part a of the gun. This movement forces the pin sideways in the
breech block towards the pivot. As the breech continues to close the pin escapes from
the incline but immediately afterwards comes against the shoulder m (see Figure 4)
and is arrested. As the breech block continues to move the finger being no longer
able to travel with it, compresses the spring; until the rear of the finger comes against
an incline n (see Figure 8) in the cam groove in the breech block. This incline forces
it to one side and it is thereby freed from the shoulder m and is forced forward by the
spring but is immediately arrested by the shoulder o in the cam groove. The gun
is now cocked. The finger gl can be released from the shoulder o and the gun fired
in any convenient manner. In figures 1 and 2 p is a trigger operated by a lanyard.
The upper end of this trigger has an arm p¹ (see figure 2) which actuates a plunger p²
having an incline p³ at its upper end which as it rises comes against the lower end of
the finger gl and forces it to one side until it clears the shoulder o whereupon it is
released and being forced forward by the spring j fires the gun.
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 breech block having a curved face corresponding to the bore of the gun and

page_text: two plane faces one on either side of it, theso faces and the corresponding faces
on the gun being provided with interlocking grooves and ridges substantially. as
described.
2. A gun whose breech block interlocks with it and in opening first moves transversely
to the bore and then turns about a pivot substantially as described.
3. The breech block having in it a hole of a key hole like form and mounted on a
spindle partly cylindrical and partly flat sided substantially as described.
4. The means for operating the breech block consisting of a lever.handle and cam
slot substantially as described.
5. The construction and method of actuating the firing pin substantially as
described.
6 My
provements in breech loading guns substantially as described.