GB580243A - Improvements in or relating to fuzes for projectiles - Google Patents

Abstract

580,243. Projectile fuzes. BLACKMAN, W., and HULSE, F. W. Sept. 23, 1941, No. 12294. [Class 9 (i)] Relates to arming devices for the fuzes of rocket projectiles (such projectiles having a low initial acceleration and little spin) of the kind actuated when the external air pressure developed during flight and acting on a piston in a cylinder exceeds a predetermined value and produces a sudden movement of the piston to effect arming. According to the invention, the effective area of the piston subjected to air pressure is suddenly increased following initial movement' of the piston, thereby accelerating the piston to complete the arming. In the form shown applied to a time fuze having combustion rings 3, 4, the piston 7 is retained against a shoulder C<1> in the cylinder by the pressure of a spring 14, the lower end of which rests on a shoulderedstriker 13 that engages pivoted latches 15 which in turn engage the piston. The arrangement is such that the external air pressure acts through'passages B first to move the piston suddenly to expose a larger area to the pressure, the latches being turned first to raise the striker and compress the spring 14 and then to permit release of the striker to pierce the detonator 20. Passages 40 leading to the outside slipstream serve to reduce the pressure below the piston. A safety stop 21 below the striker is turned aside by hand when the fuze is set. The time of arming can be adjusted by rotating the screwed member 17 carrying the latches and locking by a pin 41. Specification 579,921 is referred to.