Improvements in Breech Closing Mechanism for Ordnance.
Year: 1897

page_text: Date of Application, 4th Oct., 1897-Accepted, 15th Jan.,
1898
COMPLETE SPECIFICATION.
Improvements in Breech Closing Mechanism for Ordnance.
We, MICHEL DARMANCIER, and AIME DALZON, both of 10, Rue du Chateau-d'Eau,
Paris, France, 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, reference being had to the accompanying draw-
ings and to the letters and figures marked thereon, that is to say:
This Invention relates to breech closing mechanism for ordnance of any calibers,
and it has reference more particularly to the firing mechanism, the safety devices,
and the mechanism for operating the breech.
The object of our Invention is to enable the successive cocking and releasing
of the firing pin to be effected by one pull on the lanyard, and to avoid premature
firing, whatever the form of the breech mechanism, and further, to prevent the
unlocking of the breech in case of hang-fire when the locking and unlocking
movements are effected by a single rotary movement of the breech lever.
The combination in a breech mechanism of these improved arrangements consti-
tutes an entirely distinct locking means, which we have shewn, by way of example,
in the drawings, and which are supposed to be used in connection with case-shot,
but it must be understood that we do not limit ourselves thereto.
In the accompanying drawings,
Fig. 1 is a rear end view of the breech mechanism locked.
Fig. 2 a plan of the same, and
Fig. 3 a longitudinal section taken on the line A, B, of Fig. 1, the breech being
supposed to be locked and the shot fired.
Fig. 4 represents a similar view, to the previous figure, of a slightly modified
arrangement.
Fig. 5 is a horizontal section taken on the line C, D of Fig. 1, and through the
breech end, the locking mechanism and the extractor being shewn in plan, and in
position when the breech is fully open.
Figs. 6 to 8 are horizontal sections of the breech and its mechanism, taken on
the line E, F of Fig. 1, showing in detail, and in its various positions, the safety
device for use in case of hang-fires, and Fig. 6 shewing the position occupied by the
same at the moment of firing; Fig. 7 that after firing, and Fig. 8 that at the
moment of turning the lever against the rear of the breech screw and before
the handle bolt has entered the recess in the swinging carrier.
The firing mechanism, Fig. 3, comprises the firing pin 1, which is pressed for-
ward by its spring 2 and operated rearwardly by a lever 3 movable about a trans-
verse axis 4 carried in the breech screw 5 (or breech closing block). This lever 3
carries an axis 6, on which is loosely pivotted a tappet or pawl 7, and at the lower

page_text: end of said lever there is pivotted a bar 8 to which is attached the lanyard 9. These
various parts are always under the action of a coiled spring 10 which, by press-
ing on the lever 3, tends to restore them to the position shewn in Fig. 3.
A similar action may, as hereinafter described, be obtained by the arangement
shewn in Fig. 4, wherein a lever 11 is substituted for the spring 10 and is movable
about an axis 12 carried by the breech screw (or block) 5. One end of this lever
is in contact with the lever 3, and the other end serves as a bearing for the spring 2
of the firing pin 1. The spring 2 is subjected to an initial compression strong
enough, by acting on the lever 11, to restore the lever to its normal position
directly the lanyard 9 is released. The other parts of the mechanism are the same
as those illustrated in Fig. 3.
The lever 3 is provided at its upper end with a nose 13 which, when the breech
is completely closed, is free to enter a recess 14 in the swinging screw-carrier 15
(or in the breech). In this closed position, the end 16 of the lever 3 comes exactly
in front of a circular groove 17 formed in the breech, or in the extractor 18, or
in the swinging screw-carrier (if the closing of the breech is effected by a screw),
or in the breech (if closed by a block).
In the arrangement shewn, in the drawings as having a locking screw and a
screw-carrier, the latter is provided with a helicoidal transverse groove 19, and a
longitudinal groove 20, to receive the extremity 16 successively, during the
rotation and the removal of the breech screw 5.
In the screw-carrier (or in the breech) is formed an inclined plane 21 (Fig. 1)
along which passes the nose 13 at the beginning of the rotary movement of the
breech screw,
for the purpose hereinafter explained.
The locking bolt 22, controlled by a spring 23 (Fig. 1) carried by the breech
lever 24 is provided with a lug or projection 25 which comes opposite the bar S
when the bolt 22 is not in its locking position.
Through a tapped nut.26, formed in one with the breech screw 5, is screwed a
split pin 27 (Fig. 3) adapted to enter a hole 28 drilled in the rear end of the firing
pin 1 in such a position that the point of this latter is away from the primer so
long as the firing pin is held by the pin 27.
In the modification shewn in Fig. 4, the split pin 27 is carried by the lever 24,
and its lower extremity is caused to enter a hole 28 in the bar 8 whenever the
firing pin is brought into the safety position, as will be hereinafter described.
The breech closing mechanism is further provided with a safety device for
guarding against accident through hang fire, consisting essentially of an inertia
block or plunger 29, Figs. 1, 6, 7 and 8, located near the interlocking lug 30 of
the lever 24. This inertia block or plunger is urged outwardly by a coiled
spring 31, and is adapted to be held by a stop 32 actuated by a spring 33.
The entire mechanism is operated by a handlever 24 (Fig. 5) movable about
a pin 34, and connected with a pinion 35 gearing into the helicoidal threads 36
on the breech-screw 5.
The operation, taken step by step, is as follows, supposing the gun to have been
just fired and to have returned to battery. The various parts of the firing
mechanism are in the position shewn in Fig. 3 (or in Fig. 4) having been brought
thereinto by the action of the springs 2 and 10 in the first case, or by the spring 2
alone in the second case, owing to the initial compression of such springs.
On the recoil of the gun after the preceding firing, the spring 31 of the safety
device, (intended to prevent any dangerous opening of the breech when hangfire
has taken place) is compressed and the block or plunger 29, by reason of its
inertia, has advanced on the finish of the recoil to the forward end of its stroke
(as shewn in Fig. 7) relatively to the breech mechanism, in which position it is
caught by a stop 32 which has been pushed outwards by its spring 33.
In this state the breech is free to be opened in the following manner:
The lever 24 is gripped by its handle and, at the same time, the bolt 22 is
pressed inwards by the fingers and the lever then turned from left to right until
it strikes against the reinforced end of the breech, as shewn in Fig. 5. This

page_text: 5
movement, which takes place about the axis 34 while the breech screw is being
disengaged from its threads, and then about the axis 37, determines the rotation
and the removal of the breech screw 5 through the gearing of the helicoidal teeth
of the pinion 35 with the corresponding threads 36 on the screw 5.
On. the finish of the movement about the axis 37, the shock to the carrier 15
causes the extractor 18 to eject the empty case from the breech.
On the beginning of the movement of the lever 24 about its pin 34, the lug or
projection 30 becomes disengaged from its recess, and after having moved rear-
ward a slight distance (about 2 m/m.) behind the inertia block or plunger 29
pushes back the stop 32 and thereby disengages said block which now, under the
action of its spring, comes first against the lug or catch 30 (see Fig. 8) and then,
on the lever moving away, takes up the position shewn in Fig. 6.
After the gun has been loaded, the breech is closed in a similar, but reverse,
manner to that described with reference to the opening of the breech.
During the closing movement, the lug 30 moves the inertia block 29 inwards to
a distance of about 2 m/m. from its forward position which is insufficient to lock it
(position represented in Fig. 8), then the lug 30 being in the position "breech
closed" the block 29 takes up the position shewn in Fig. 6 thus preventing the
breech from being opened so long as the charge has not been fired, especially when
hang-fire occurs. The breech being thus securely closed and the firing pin 1 held
at the forward end or its stroke by the spring 2, which takes up its bearing either
directly on the screw 5 (or breech block), or through the medium of a plug fixed
to the rear end of such screw or block, it is only necessary, in order to effect the
cocking and the release of the firing pin, to pull the lanyard 9 as far as it will go.
The lever 3 then turns on its axis 4, the pawl or tappet 7 engages the heel or
flange 38 of the firing pin, and the springs 2 and 10 (or only the spring 2 in the
arrangement shewn in Fig. 4) are compressed towards the rear. At the end of
the stroke of the lever 3, the tappet 7 escapes from the heel or flange 38 by reason
of the neb of the tappet moving through an arc of a circle, having for its centre
the axis 4, and the firing pin 1 following a straight line, and said firing pin is
shot forward by its spring against the primer or fuze. If in the second position of
the lever 3, the lanyard be not pulled, the lever 3 is restored to the forward position
by the spring 10 Fig. 3 (or by the spring 2, Fig. 4). During this movement, the
tappet 7 slides over the heel or flange 38 of the firing pin and turns, relatively to
the lever 3, on its axis 6. At the end of the forward movement of the lever 3,
the extremity 39 of the tappit 7 strikes against the bottom of the groove in the
breech screw (or breech block) and is thus restored to its initial position.
It is clear from what has been stated that, for cocking and releasing the firing
pin, it needs but to exert a full pull on the lanyard, and for repeating this
operation, to allow the lanyard to return to its initial position, and this may be
effected as often as may be desired without interfering with the breech mechanism.
The nose 13 of the lever 3 serves to prevent premature firing. To this end, it
cts concurrently with the opposite extremity 16 of the same lever and establishes
relation between the firing mechanism and the swinging carrier 15, or the breech,
the said mechanism being dependent on the hand lever 24, through the bar 8.
It will thus be understood, from the preceding, that in order to enable the
ever 3 to move and effect the cocking and the releasing of the firing pin 1, and
o repeat these movements, the nose 13 must be opposite the recess 14 in the swing-
ng carrier 15 (or in the breech) when the breech screw 5 (or breech block) is in
ts locked position, and that, in this position, the extremity 16 must be exactly,
pposite the circular groove 17.
In any other position, the lever is prevented from moving sufficiently to produce
he cocking for firing. In the case (taken by way of example) where a breech
crew and carrier are employed, a helicoidal transverse groove 19 and a longitudinal
roove 20 are formed in the carrier 15 to receive the extremity 16 successively
uring the rotary and linear movements of such breech screw 5, and said two
rooves prevent the full movement of the lever 3.

page_text: The nose 13 has further for its purpose to prevent the firing pin 1 from project-
ing into the breech screw (or block) at any other time then when the breech is
closed, by partially cocking the firing pin 1 so far as to bring the striking point
of the latter inside the front end of the screw (or block) by about 2 to 3 m/m., and
retaining it until the breech is completely closed. This result is obtained, from
the very commencement of opening of the breech, by the nose 13 sliding over
the inclined plane 21 which forces the lever 3 to move slightly backward, and
therefore to cause the firing pin 1 to retire sufficiently to prevent the point of the
latter protruding beyond the front face of the screw 5 (or block)..
The lug or projection 25 on the locking bolt 22, provided with the spring 23,
serves to prevent the bar 8 being moved by the lanyard 9, so long as the lever 24
is not engaged in the carrier 15 (or in the breech). The said lug comes in front
of the rear end of the bar 8 whenever the bolt is not locked, and hence prevents the
cocking, and the releasing, of the firing pin 1, which obviously can only be
effected when the bar 8 is permitted to move freely. But in this instance, the bar
is prevented from being moved by the lug 25 which hinders it so long as the
locking bolt 22 has not gone fully home.
The screw split-pin 27, carried in the tapped lug 26 of the breech screw, is
provided for the purpose of preventing accidental firing en route, or during mani-
pulation, when the gun is loaded. To this end, while the gun is not in battery,
and in its firing position, the split pin remains engaged in the hole 28 in the
rear end of the firing pin 1 so as to keep the point of the latter away from the
primer.
In the modification shewn in Fig. 4, the hand lever 24 carries the screw split-
pin 27, and the hole 28, into which such pin engages (whenever the firing pin is
to be placed into a safety position) is arranged in the bar 8, but the operation is
absolutely the same as in the previous case.
The type of breech mechanism which we have just described, by way of example,
is particularly adapted for use with case shot, but it is evident that the same
system may be adapted equally well, and without any essential modification, to
breech closing mechanism with plastic obturation where the projectile is inde-
pendent of the charge.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same may be performed, we declare that what
we claim is:-
1. In breech closing mechanism for ordnance of any calibres, a percussion firing
mechanism consisting essentially of a spring firing pin (1), the cocking and
the releasing of which are effected at one and the same time by means of a lever (3)
pivotally arranged within the interior of the breech screw (or breech block) and
operated by means of a lanyard, the said lever actuating the firing pin through
the medium of a pivotted pawl or tappet and remaining engaged, during the
opening and closing movements of the breech, in grooves in the swinging carrier
(or in the breech block, or in the breech.
2. In breech closing mechanism for ordnance of any calibres, a safety device
consisting of a screw split-pin (27) carried in the breech screw, the closing block,
or the breech lever, and adapted to enter a hole (28) in the rear end of the firing
pin, or its controlling bar 8.
3. In breech closing mechanism for ordnance of any calibres, a safety device
(in case of hang-fire), consisting of a spring-controlled inertia block or plunger (29)
arranged near the engaging lug or projection of the hand lever and capable of
being retained by a spring stop (32) actuated by the said lug or projection.
4. The combination, in a breech closing mechanism, of the arrangements above
claimed, said combination constituting substantially our improved breech closing
mechanism herein before described and represented in the annexed drawings, and
in which both the opening and the closing of the breech are effected by a single

page_text: augurar movement of the hand lever about the axes 34 and 37, at right angles to
the axial line of the gun, said lever carrying a lug (25) so arranged as to prevent
premature firing.
Dated this 4th day of Octobox 1907
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5A, Market Street, Nottingham,
Agent for the Applicants.