SE325495B - - Google Patents

Abstract

1,177,824. Breech mechanism. RHEINMETALL G.m.b.H. 22 March, 1967 [24 Jan., 1967] No. 13474/67. Heading F3C. An automatic firearm is provided with a masstype breech mechanism with an inertia force intensifier comprising two or more accelerating systems arranged serially at the rear of the head of the breech mechanism, each system including a mass element and corresponding rolling means exerting a mass accelerating function by co-operation with corresponding inclined surfaces. In the embodiment of Fig. 5 rollers 14 are each abutted by a head 3, associated with the rear end of the barrel, inclined faces 10 on abutments 1 secured to the weapon casing, and faces 15a on a control piece 15 on the mass 4 of the first accelerating system. The second system includes a ball or roller 16 abutted by inclined faces 18, 29 and 28 on the head 3, the first mass 4 and the part 21 respectively. When the barrel and head 3 recoils a distance a the parts move to the positions shown in dotted lines, the first mass moving through distance b and the part 21 moving through a distance c which, with the particular values of the inclinations given in the Specification, is 9À8 times that of a. In a particular application (Figs. 2-4, not shown) the planes of the rollers 14 and 18 are positioned at right angles. In a further embodiment shown schematically in Fig. 1 the rollers 9 of both systems have abutment against projecting faces on the weapon body 1. The inclined faces may be curved and the mechanism is suitable for larger calibre weapons than the rapid firing weapon shown.