Improvements in the Breech Mechanism of Guns.
Year: 1890

page_text: Date of Application, 25th June, 1890
Complete Specification Left, 25th Mar., 1891-Accepted, 20th June, 1891
PROVISIONAL SPECIFICATION.
Improvements in the Breech Mechanism of Guns.
We, ANDRE THEODORE CHRISTOPHE, of 5 Rue Meyerbeer, Paris, in the
Republic of France, and PER NORDENFELT, of 32 Victoria Street, in the City
of Westminster, Engineers, do hereby declare the nature of this invention to be as
follows:-
This invention relates to breech loading guns in which the breech is closed by a
cylindrical block having segments of screw threads upon it engaging with
corresponding segments in the gun and in which in opening the breech, this block
has to be turned partly round to disengage the screw threads, then to be drawn
back into a carrier ring which surrounds it and finally when clear of the gun has
to be moved to one side and rearwards around an axis tangentially situate in
relation to the carrier ring and on which this ring is mounted.
In order to impart these movements to the breech block and carrier ring in
opening the breech and opposite movements when closing the same we fix an arm
to the rear face of the breech block and provide the same with a roller which
works in a helicoidal groove cut on a sleeve on the axis about which the carrier
ring turns. We further provide rack teeth cut on the block itself when the
breech block has been turned by the arm the teeth on the breech block engage in
a set of cogs cut upon the sleeve. The rotation of the breech block through the
action of the roller on the end of the arm and the helicoidal groove is sufficient to
disengage the screw segments, and the rack on the breech block then becomes
engaged by the cogs on the sleeve, the breech block is drawn rearwards.
The rotation of the sleeve and axis about which the carrier ring turns thus
causes the rotation and withdraws the breech block.
As soon as the breech block gets clear of the gun it is unable to travel back
further through the carrier ring and then the cogs on the sleeve still acting upon
the rack teeth, the sleeve with the breech block and carrier ring move together
around the axis until the bore of the gun is accessible for the insertion of a new
cartridge. Similarly in closing the breech the rotation of the axis first brings the
carrier ring back to its place, then drives the breech block forward into the gun
and finally turns the breech block and so locks it in place.
The axis above mentioned has a bevelled pinion upon it which gears with a
toothed sector upon another axis parallel to the bore of the gun. This axis may
be turned by means of a crank handle at its rear end but usually we provide
mechanism such as is described in our Patent No. 12777 in the year 1888 to rotate
it to open the breech as the gun moves forward after recoil and to cause it to
return by the operation of a spring when it is liberated after a fresh cartridge has
been put into the gun
A. T. CHRISTOPHE.
PER NORDENFELT.
COMPLETE SPECIFICATION.
Improvements in the Breech Mechanism of Guns.
We, ANDRE THEODORE CHRISTOPHE, of 5 Rue Meyerbeer, Paris, in the
Republic of France, and PER NORDENFELT, of 32 Victoria Street, in the City
of Westminster, Engineers, 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

page_text: cylindrical block having segments of screw threads upon it engaging with
corresponding segments in the gun and in which in opening the breech, this block
has to be turned partly round to disengage the screw threads, then to be drawn
back into a carrier ring which surrounds it and finally when clear of the gun has
to be moved to one side and rearwards around an axis tangentially situate in
relation to the carrier ring and on which this ring is mounted.
We impart these movements to the breech block and carrier ring in opening the
breech and opposite movements when closing the same by means of a sleeve upon
the axis of the carrier ring. We fix an arm to the rear face of the breech block
and provide the same with a roller which works in a helicoidal groove cut in the
sleeve. We further provide rack teeth cut on the block itself and cogs upon the
sleeve to engage with these rack teeth.
When the axis and sleeve are rotated in opening the breech the groove and the
arm turn the breech block.
The rotation of the breech block through the action of the roller on the end of
the arm and the helicoidal groove is sufficient to disengage the screw segments and
to bring the rack on the breech block into engagement with the cogs upon the
sleeve. Then by the further rotation of the sleeve and axis the breech block is
drawn rearwards.
The rotation of the sleeve and axis about which the carrier ring turns thus
causes the rotation and withdraws the breech block.
As soon as the breech block gets clear of the gun it is unable to travel back
further through the carrier ring and then the cogs on the sleeve still acting upon
the rack teeth, the sleeve with the breech block and carrier ring move together
around the axis until the bore of the gun is accessible for the insertion of a new
cartridge. Similarly in closing the breech the rotation of the axis first brings the
carrier ring back to its place, then drives the breech block forward into the gun
and finally turns the breech block and so locks it in place.
The axis above mentioned has a bevelled pinion upon it which gears with a
toothed sector upon another axis parallel to the bore of the gun. This axis mayibe
turned by means of a crank handle at its rear end but usually we provide
mechanism such as is described in our Patent No. 12777 in the year 1888 to rotate
it to open the breech as the gun moves forward after recoil and to cause it to
return by the operation of a spring when it is liberated after a fresh cartridge has
been put into the gun.
In order that our said invention may be fully understood and readily carried
into effect we will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation partly in section of the breech mechanism of a gun
made in accordance with the other arrangement previously referred to.
Figure 2 is a rear elevation of the same and
Figure 3 is one half of a horizontal section on the line 6, 6 in Figures 1 and 2,
but with the breech block its rack sleeve and cogs on the same which drive it,
shown in plan.
A is the breech of the gun, B is the screw breech block. C is the carrier ring
in which the breech block is held and in which it is able to move longitudinally.
D is the axis upon which the carrier ring is mounted. E are the rack teeth cut on
the breech block. F is the sleeve on the axis D. G is a bevelled pinion on the
same axis and in gear with the sector H, I is the axis on which the sector H is
carried. is the lever fixed to the breech block. Jis the roller attached to the
same. F is the groove in which the roller works. Fare the cogs which engage
in the rack E for withdrawing the breech block; H' is a notch in the sector H
into which a pawl K drops, it serves to hold the breech open until it is lifted by
pulling the string K¹. At L is the control apparatus which by springs and
hydraulic appliances regulates the recoil and the return of the gun to the firing
position.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we would state that
we do not now claim either the screw breech block or the carrier ring in which it
is mounted or the mechanism for regulating the recoil or the mechanism described
in our former Specification for automatically turning the axis I, for all these
arrangements are already known, but what we claim is:-
1. Breech mechanism in which a screw breech block mounted in a carrier ring is
actuated by a lever fixed to the breech block with a roller engaging in a groove
cut on a sleeve on the axis of the carrier ring and by rack teeth on the breech
block gearing with cogs on the sleeve.
2. The combination of parts viz.: the breech A; the breech block B with its
arm J, and roller J₁; the carrier ring C; the axis D of the carrier ring; the
rack teeth E, on the breech block; the sleeve F with its groove F¹ and cogs F",
the axis I parallel to the bore of the gun and gear connecting the axes D and 1.
Dated this 25th day of March 1891.
CARPMAEL & Co.,
Agents for the Applicants.