Patent GB-790879-A (GB)
Title: Device for the control of the breech of a double-barrelled gun
IPC: F41A5/00
Filed: 1956-01-31
Abstract: 790,879. Firearms. SOC. DES FORGES ET ATELIERS DU CREUSOT. Jan. 31, 1956 [Feb. 3, 1955], No. 3049/56. Class 92 Relates to a breech mechanism of a double-barrelled gun, the barrels of which are fired successively although the breech is common to both barrels which thus recoil at the same time. According to the invention the control of the breech is effected by a carriage constituted by two cam assemblies 11, 12, Figs. 1, 2, each corresponding to the portion of the breech 1 associated with a single barrel 2 or 3, this carriage being slidable laterally on guides 21, 22 in such a manner that when one cam assembly 11. 12 comes into the path of levers 9, 10 mounted in the breech and controlling the ejector and the breech block of that portion of the breech corresponding to one barrel, the other assembly 11, 12 is withdrawn from the path of levers corresponding to the other barrel. An eccentric 29 mounted in the breech casing effects the sliding movement of the cam assemblies and is actuated by a changeover mechanism carried by the breech. During recoil the lever 10 is rocked by riding on the cam 11 to effect the lifting of the wedge block 13, Fig. 3, by means of another lever 8 and at the same time the lever 9 is rocked by riding on the cam 12 to operate the ejector 6. Final ejection of the cartridge is effected when a projection 85 on each of the lateral faces of the wedge 13 hits a spur 86 carried by each of the branches of the ejector 6: Fig. 3 shows the different phases of recoil. At the beginning of recoil, the wedge 13 closes the breech. At the next stage the levers have been rocked and the branches of the ejector 6 begin to detach the cartridge 14 by rocking a pivotally mounted abutment 16 about a pivot 15; at the same time the wedge 13 is lifted. At the end of recoil, the wedge 13 has been raised to a maximum and the abutment 16 moved to a rear position in which it supports the wedge 13 in the course of restoring the gun to the firing condition. The insertion of a new cartridge into the barrel restores the ejector to its original position together with the abutment 16 and thus effects the closing of the breech by the wedge 13 which is biased in the closing direction by a device such as a torsion bar. The two cam assemblies slide on bars 21, 22, Fig. 1, and can pivot about the bar 21 but are normally held against such movement by hooked levers 23 held in position by a breaking link 26. If .abnormal resistance prevents rocking of the levers 9, 10, the link 26 snaps and the cam assemblies rock about the bar 21. The eccentric 29 is mounted between two plates 30, Fig 2, on a sleeve 20 connecting the two cam assemblies and is rotated by movement of a lever 38, Fig. 1, this movement being effected by the change-over mechanism carried by the breech during movement of the breech. This change-over mechanism 49, 71, 72. 75, 76, 79 which comprises a system of levers, cams and rods ensures that in timed relationship with the lateral movement of the cam assemblies, the appropriate sear for the firing pin of one barrel is locked whilst the sear for the firing pin of the other barrel is unlocked and vice versa.