Improvements in Breech Loading Small Arms.
Year: 1894

page_text: Date of Application, 24th Feb., 1894-Accepted, 16th June, 1894
COMPLETE SPECIFICATION.
Improvements in Breech Loading Small Arms.
I, ALFONSO DUNI, Major of Artillery, of Piazza Statuto 9, Turin, in the
Kingdom of Italy, 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 for improvements in breech loading small arms relates to fire
arms in which the breech is closed by a bolt working longitudinally and locked
by a partial rotary movement and has for its object to effect all the operations
of loading and cocking by a straight backwards and forwards movement of
the hand.
In the accompanying sheet of drawings
Fig. 1 shows detail views of the parts of the breech mechanism with its loose
head and extractor.
Fig. 2 shows a slightly modified construction to that shown in Fig. 1.
Fig. 3 is a vertical longitudinal section through the breech of a gun showing the
breech-piece withdrawn.
Fig. 4 shows the firing pin and spring.
Fig. 5 is an elevation partly in section of the breech of a gun, showing the parts
in the position they occupy when the breech is closed.
The breech piece or bolt bored to receive the firing pin and its operating spiral
spring, is composed of two parts A B (Fig. 1) screwed together. The front
piece A provided with tenons A' is terminated at the back by the triangular
segmentgh the side 9 being helicoidal. This segment may be made as shown
by Fig. or as in Fig. 2. The back piece B of the breech bolt has the shape of
a tube bd smaller in diameter than the front piece A with an enlargement a ceb
of equal diameter to that of the front piece A and formed with a triangular
projection a be the side ab of which is a helicoid springing from a straight line
almost normal to the axis of the breech piece:
The cam sleeve C (Fig. 1) or C' (Fig. 2) slides on the part bd of the back
piece B and gives the desired motion to the breech piece, the handle C' having
only a straight reciprocatory motion.
The sliding sleeve and breech piece or bolt have a uniform thickness equal to
the interior orifice of the breech guide. The sleeve has two helicoidal indentations
one g h at the front and the other ab at the back, each of which is equal and
respectively arranged to correspond with the helicoidal segment g of the front
piece A and with the helicoidal segment ab of the back piece B of the
breech piece.
The sleeve C during the alternating movement is always retained in position
with the handle to the right by means of the guide runner which slides in the
straight groove of the breech guide.
As shown in Fig. 2 the sleeve C is formed with an angular indentation and a
triangular projection of which the helicoidal sides g" h" and a" have the same
pitch and surfaces equal and corresponding to those of the sides g h and ab of the
breech piece or bolt. By pushing the handle C¹ of the sleeve to the front the
mechanical action of the front helicoid g¹ (Fig. 1) or g¹¹h (Fig. 2) of the sleeve
on the helicoid g h of the front piece A. produces a rotating movement of the
breech piece to the extent of one quarter turn to the right. If the sleeve handle
is drawn to the back the action of the back helicoid a' (Fig. 1) or a" 6" (Fig. 2)
of the sleeve on that a b of the back piece forces the breech piece to make a
quarter turn to the left. Thus the rectilinear movement in the sleeve effects the

page_text: rectilinear and rotary movements of the breech piece by means of the angular
indentations in one and projections in the other or vice versa whilst the diameter of
the whole is equal to that of the front of the breech piece and corresponds with the
breech guide.
The firing pin is constructed in one single piece and comprises the rod D D¹
(Fig. 4) with the button D the point D¹ and the nose piece F. The section of the
rod D D¹ near the extremity D' is flattened or made oval to correspond with the
orifice in the loose head q g'. The nose piece F has a hole o o' (Fig. 4) corre-
sponding to the pin p (Fig. 5) on the safety mechanism and serves to prevent the
release of the firing pin when loaded. An oblique piece m m¹ on the nose piece F
is designed to act on the oblique indentation kk' (Fig. 1) of the back end of the
breech piece or bolt for the purpose of withdrawing the point of the firing pin
when the breech is opened. Also the nose piece F has a tooth o m¹ (Fig. 4)
corresponding to the groove u u¹ (Fig. 2) of the sliding sleeve C serving to prevent
any rotary movement. A spiral spring E E¹ (Figs. 3 and 4) surrounds the firing
rod and is connected to it by a forked stop H or sleeve open at one side. This
method of supporting the extremity of the spring allows the whole of the firing rod
to be made in one piece and the breech mechanism to be easily taken apart without
the aid of any tools. The loose head and extractor q q¹ is a simple disc carrying
the catch (Fig. 2). The disc is bored to correspond to the shape of the
flattened part of the firing rod in order to prevent displacement of the loose head.
It is fitted on the front of the breech block and rests against the front end W W
of the breech piece (Fig. 1) and is held by the C shaped head of the spring M M¹
(Figs. 1 and 2). For this purpose the spring M M' having the head z Mbent
in the form of an arc is provided with an angular catch towards the ends
support the disc. The central part slightly flattened of the C shaped head and at
the same time the bar M M₁ have a spring effect which permits the extractor to
seize the rim of the cartridge and to hold it gripped. The bar M M¹ is provided
with an extension y having a T shaped section which serves to hold it in its
corresponding seating in the breech piece and with a projection y' which ensures
the effective junction of the two portions A B of the breech piece.
to
This extractor has the advantage when compared with other systems of loose
head that the part of the breech piece where the locking tenons are fixed
remains solid and for that reason is better able to withstand heavy forces when
firing.
The safety mechanism is double acting, that is to say it operates to prevent the
release of the firing rod and at the same time any movement of the sleeve C and
breech piece. By raising the lever N (Fig. 5) from the back upwards the bolt P
engages in the orifice o o' (Figs. 4 and 5) of the nose piece F and firmly arrests the
firing rod and also moves back the nose piece F slightly and disengages it from
its notch; simultaneously the bolt P engages in a groove in the sleeve C and
prevents any movement of the breech piece. The lever N also acts when the nose
piece F is in position to prevent the breech opening accidentally. The safety
apparatus is not provided with a spring nevertheless the stability of the safety lever
in the two positions of the lever N is effected by the same spring used for the
trigger by means of a projection S (Fig. 3) on the trigger which bears under the
lever (Fig. 5).
The operation to open and close the breech at each shot are reduced simply to
drawing back the sleeve C' and pushing it forward. On drawing back the sleeve
the breech is rotated by the helicoidal surface of the sleeve on that of the breech
piece. The simultaneous retrograde movement of the loose head gq' of the breech
piece is effected by the slightly oblique surfaces of the projections of the
breech guide and so loosens the base of the cartridge enclosed in the barrel. The
nose piece F (Fig. 4 and 5) not being able to follow the above mentioned turning
movement is pushed back by the oblique surface k k¹ (Fig. 1) of the breech piece,
the firing rod is thus cocked and maintained thus by the entry of the nose piece in
a slot el (Fig. 1) of the cylinder. After this movement the tenons A¹ being then

page_text: opposite the slots A' in the breech guide, the breech piece or bolt is drawn back so
as to open the vertical passage for the cartridges. On pushing the sleeve C forward
the loose head seizes the base of the cartridge and carries it forward to the breech.
The tenons A sliding in the longitudinal grooves of the breech guide can only move
in a rectilinear direction consequently the firing rod which is engaged in the slot in
the breech piece and in the groove u u¹ (Fig. 2) of the sleeve can only move in a
rectilinear direction at the same time as the sleeve whilst the tenons are moved
towards the breech. When they reach the breech the tenons A¹ are beyond the
guiding grooves and by pushing the sleeve further forwards a quarter turn is given
to the breech piece and the tenons A¹ pass behind inclined projections on the breech
guide; the
part
in front of the tenons vv (Figs. 1 and 2) enters the annular
seating tst (Fig. 3 section 3, 4) of the head of the breech guide; the extractor
hook (Fig. 1 section 1, 2) penetrates into its position sx (Fig. 3 section 3, 4) so
that the disc qq' does not follow the movement of rotation whilst the edge of the
breech piece fits exactly against the ring tt' (Fig. 3 section 3, 4).
This system of breech mechanism is applicable to magazine repeating mechanism
fixed under the breech box or any other repeating mechanism.
A gun provided with this breech machanism can fire with ease and rapidity all
the cartridges enclosed in the magazine without the weapon being removed from
the shoulder.
From comparative tests of the above described weapon with one of automatic
action that is to say utilising the force of the recoil for cocking loading and closing
the breech it results that my arrangement whilst more simple and practical has the
advantage in rapidity of fire.
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 mechanism consisting of the guided breech piece with cam surfaces
and the operating sleeve sliding thereon, with corresponding cam surfaces so
arranged that the breech can be unlocked and withdrawn by one straight movement
and inserted and locked by the opposite straight movement substantially as
described.
2. The construction and arrangement of breech closing mechanism substantially
as described with reference to the drawings.
3. A stop for the spiral spring of the firing rod consisting of two opposite notches
in the firing rod and a U-shaped head adapted to be slid along the notches
substantially as described.
4. The combined loose head and extractor consisting of a disc provided with a
book and held on the end of the breech piece by the C-head of a spring secured on
the breech bolt substantially as described.
5. The safety apparatus consisting of an operating lever and parts engaging the
firing rod and in the sliding sleeve so as to hold both the firing pin and breech piece
substantially as described.
6. The improvements in fire arms substantially as described with reference to the
drawings.
Dated this 24th der of Fobma100A
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.