EP1344999A1

EP1344999A1 - Mechanism for locking the breechblock in a semi-automatic rifle

Info

Publication number: EP1344999A1
Application number: EP03075695A
Authority: EP
Inventors: Bruno Civolani
Original assignee: Oto Melara SpA
Current assignee: Oto Melara SpA
Priority date: 2002-03-15
Filing date: 2003-03-10
Publication date: 2003-09-17
Also published as: ITMI20020558A0; ITMI20020558A1

Abstract

A mechanism for locking the breechblock in a semi-automatic rifle, comprises a breechblock carrier (14), slidably guided in a breech (13) housed in a rifle casing (10), a breechblock (50) slidably supported by said breechblock carrier (14), a locking latch (40) suitable for engaging in a seat (18) realised in said breech (13) to lock the breechblock (50) at the breech (13), an cocking clip (19) consisting of a pin which crosses the casing (10), said latch (40) having a groove (42) in which said cocking clip (19) is housed, in such a way that through the mutual engagement of the cocking clip (19) in said groove (42) during the sliding back of the breechblock (50) and the latch (40) the descent of the latch (40) is permitted to release it from engagement in the seat (18) of the breech (13) when a shot has been fired.

Description

The present invention concerns a mechanism for locking the breechblock in a semi-automatic rifle.
In particular, the invention concerns a safety mechanism suitable for holding the breechblock of an inertia operating semi-automatic rifle in closed position during the blasting of the cartridge and to then lock it until the insertion of the next cartridge in the chamber.
For some time inertia operation rifles have been known, in which the kinetic energy of the breechblock group is exploited, sliding open backwards following the blasting of the cartridge, to obtain the expulsion of the cartridge case and the loading of the next cartridge in the chamber.
In rifles currently known there are different mechanisms and ratchet gears with automatic operation and/or controlled from the outside through buttons, to ensure safety of the firearm during firing and unlocking during the subsequent steps.
Such mechanisms are in general somewhat complex and expensive and some of these are delicate for sporting use as a hunting rifle.
The purpose of the present invention is that of providing a mechanism for closing the breechblock in a semi-automatic rifle which allows the aforementioned drawbacks of the prior art to be avoided and which ensures high safety in use of the rifle.
This purpose is accomplished according to the present invention by realising a mechanism for locking the breechblock in a semi-automatic rifle according to that which is outlined in claim 1.
Further characteristics of the invention form the object of the dependent claims.
The mechanism for locking the breechblock of a semi-automatic rifle object of the present invention comprises a breechblock carrier, slidably guided in a breech housed in a rifle casing, a breechblock slidably supported by said breechblock carrier, a locking latch suitable for engaging in a seat realised in said breech to lock shut the breechblock at the breech, a cocking clip consisting of a pin which crosses the casing, said latch having a groove in which said cocking clip is housed, in such a way that through the mutual engagement of the cocking clip in said groove during the sliding back of the breechblock and of the latch the lowering of the latch is allowed to unlock it from the engagement in the seat of the breech when a shot has been fired.
The characteristics and advantages of the mechanism according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings, in which:

figures 1 to 6 illustrate side section views of a detail of the rifle carrying the mechanism according to the invention during various operating steps;
figure 7 illustrates an enlarged detail of the mechanism according to the invention;
figures 8 and 9 show two of the details of the mechanism illustrated assembled in figure 7.

With reference to the figures, a casing 10 of a semi-automatic hunting rifle houses, inside its housing 11, the sear mechanisms for the firing of shot cartridges 12, preferably but not exclusively calibre cartridges 12.
Inside a breech 13, consisting of the elongation of the barrel of the rifle in the housing 11, a carrier 14 slides carrying, arranged inside of it, the breechblock 50.
Between breechblock 50 and carrier 14 is placed an inertia spring 16 the function of which is that of compressing during the recoil backward motion of the breechblock 50 following firing to then restore its elastic energy, up to a certain compression threshold, thrusting the carrier 14 which has a relatively large mass with respect to that of the breechblock 50.
The carrier 14 in practice recoils and frees a latch 40 protruding from the breechblock 50.
Said latch 40, during all of the firing step, is engaged in a seat 18 realised in the breech 13 so as to lock making the breech 13 and breechblock 50 integral.
For this purpose, the latch 40 is made in the form of a cylindrical pawl so as to be able to be inserted in a corresponding circular opening 51 realised in the breechblock 50.
The latch 40 has an upper portion 41 which has the purpose of coupling with the seat 18 present on the breech 13 holding the breechblock when the locking is realised.
The latch 40 also has, in the lower portion of its casing, a groove 42 in which an cocking clip 19 consisting of a pin which crosses the casing 10 is housed.
Such a groove 42 has, in the lower portion, a tilted plane 43 along which the cocking clip 19 slides during the sliding back of the breechblock and of the latch so as to allow the lowering of the latch 40 to release it from engagement in the seat 18 of the breech when a shot has been fired.
With particular reference to figures 7 to 9, the latch 40 has, in a central position, a slot 44 in which a dowel screw 52 is inserted fixed in the opening 51 of the breechblock to hold the latch 40 in the opening 51 during its vertical engagement/disengagement movement in the seat 18 so as to avoid it slipping out.
A firing pin 20 axially crosses the carrier 14 of the breechblock 50 and the latch 40 passing in the longitudinal openings arranged for the purpose so as to be able to strike, upon firing of the hammer, the base plate of the cartridge in which the capsule which starts off the blast is arranged.
For a description of the operation of the mechanism according to the invention we consider the state in which the cartridge 12 is inserted in the chamber 30 of the rifle, which has the carrier 14 of the breechblock 50 closed, and one wishes to fire.
In this state the inertia spring 16 is unloaded, the latch 40 is locked engaged in the seat 18 present on the breech 13 and one is ready to fire.
The firing state is absolutely safe since the locking latch 40 cannot come out of the locked state. To do this it should descend until it no longer interferes with the notch present on the breech 13, but it cannot do so since it is blocked by the lower plane 14' of the carrier 14.
At this point firing takes place, the firearm recoils backwards and the breech 13, the breechblock 50 and the latch 40 move back integral with it, keeping the rifle locked, with the exception of the carrier 14.
The carrier 14, maintaining its position, allows the compression of the inertia spring 16 until there is no inversion point in which the inertia spring 16, compressed, releases its energy thrusting back the carrier 14 itself creating the conditions for the subsequent unlocking.
The carrier 14 slides back pulling with it the spent cartridge case 12, until the plane which blocks the descent of the latch 40 has completely displaced.
The cocking clip 19 comes up against the tilted plane 43 of the latch 40 and allows it to descend releasing it from the locked state.
The carrier 14 proceeds on its stroke until the cartridge case has been ejected, after which either it remains open held by a stop tooth 31 of the breechblock since the spent cartridge 12 was the last one present, or else, if there is another available cartridge, the breechblock goes back to advance putting the aforementioned cartridge into the chamber for the next shot.
In particular, in the instant in which the latch 40 leaves the seat 18 of the breech 13 which keeps the rifle locked, the rifle is in a safe condition in any case.
Hypothetically, if in such a condition there were a cartridge 12 ready for firing in the chamber 30 and the firing pin 20 were made to advance completely, the firing pin 20 would not protrude from the breechblock 50 but would remain some millimetres inside it.
This means that in the most critical situation for the rifle, i.e. when it has left the locked state but the breechblock group 50 is still in advanced position, the firing pin 20 does not have the physical possibility of firing the capsule allowing premature blasting.

Claims

Mechanism for locking the breechblock in a semi-automatic rifle, comprising:

a breechblock carrier (14), slidably guided in a breech (13) housed in a rifle casing (10);

a breechblock (50) slidably supported by said breechblock carrier (14);

a locking latch (40) suitable for engaging in a seat (18) realised in said breech (13) to lock the breechblock (50) at the breech (13);

a cocking clip (19) consisting of a pin which crosses the casing (10), characterised in that said latch (40) has a groove (42) in which said cocking clip (19) is housed, in such a way that through the mutual engagement of the cocking clip (19) in said groove (42) during the sliding back of the breechblock (50) and the latch (40) the descent of the latch (40) is permitted to release it from engagement in the seat (18) of the breech (13) when a shot has been fired.
Mechanism for locking the breechblock according to claim 1, wherein said groove (42) has, in its lower portion, a tilted plane (43) along which the cocking clip (19) slides.
Mechanism for locking the breechblock according to claim 2, wherein said latch (40) has an upper portion (41) suitable for coupling with the seat (18) present on the breech (13) to hold the breechblock (50) when the locking is realised.
Mechanism for locking the breechblock according to claim 3, wherein said carrier (14) has a lower plane (14') suitable for blocking the descent of said latch (40) to hold it in the seat (18) until the sliding back of the breechblock (50).
Mechanism for locking the breechblock according to claim 4, wherein said latch (40) is realised in the form of a cylindrical pawl so as to be able to be inserted in a corresponding circular opening (51) realised in the breechblock (50).
Mechanism for locking the breechblock according to claim 5, wherein a stop tooth (31) of the breechblock is foreseen to hold the carrier (14) in open position following sliding back after a shot.