GB928735A - Improvements in or relating to mechanical time fuzes, particularly for a submarine explosive charge - Google Patents

Abstract

928,735. Clockwork fuzes; mines. MEFINA S.A. Jan. 15, 1960 [Jan. 17, 1959], No. 1516/60. Classes 9 (1) and 9 (2). A mechanical time fuze, particularly for use in marine mines, comprises a timing-shaft 15 housing a spring-actuated striker 13, a clockwork motor 21 with gear train 24 and 25-28 (not shown) which drives a shaft 22 via a toothed wheel 23, a primer 12 in a rockable support 9 and a detonator 6. The fuze is timeset by rotation of the timing-shaft 15 by means of operating member 50, the timing-shaft being connected, for rotation only, to a time-disc 57. This disc may only be rotated after pushing radially inwards the ends 69 of two locking levers 63 (Fig. 2) thereby disengaging ends 65 of the levers from teeth 68. Arming of the fuze is brought about partly manually and partly by working of the clockwork mechanism. The timing shaft 15 is rotated as above and then pulled axially outwards by means of operating member 50, a pin 52 engaging a recess 56 to lock the timing-shaft against the action of a spring 47 and at the same time releasing member 50 and its associated spindle 51. The axial movement of the timing-shaft brings the centre of a hole 40 therein into the same horizontal plane as the centre of a hole 41 in the shaft 22, the holes, however, being angularly displaced due to the initial rotation imparted to the timing-shaft. At the same time a rod 43 is disengaged from a balance wheel 29 to free the clockwork mechanism. An auxiliary safety device comprises a protruding edge 71 of a plate 48 which overlaps a projection 74 of the timing-shaft 15, which device prevents axial movement before a prior and predetermined amount of rotation of the timing-shaft has been made. The support 9 rotatable about an axle 10 under the action of a spring 11 is held with primer 12 out of alignment with the line of movement of striker 13 by a lug 75 which depends from shaft 22 (Figs. 1, 6). A small predetermined rotation of the shaft 22 by the clockwork mechanism frees the support 9 to fully arm the fuze and continued rotation brings holes 40, 41 into alignment after the set time thereby allowing a ball 37 to escape and striker 13 to impinge on primer 12. In the embodiment described a fluid-tight sealing ring 5 is provided between a body 1 and sheath 3 of the fuze and flexible linings 49 ensure fluidtightness between body 1 and timing-shaft 15.