Fuze with bimetallic spring delay module

Claim 1

A fuze providing delay arming and impact functioning of a munition, which comprises a bimetallic spring delay module comprising a bimetallic spring, and a pyrotechnic charge for heating said spring, said spring being capable of inverting from a first stable position to a second stable position by heat from the pyrotechnic charge and of reverting to said first position by cooling, a detonator, a firing pin driven by impact of the fuze with a solid target, and a safing and arming means attached to said bimetallic spring for preventing contact of the firing pin with the detonator when the spring is in said first position, and for permitting contact of the firing pin with the detonator when the spring is in said second position; whereby ignition of the pyrotechnic charge causes the bimetallic spring to be heated and to invert from said first position, wherein the fuze is in an unarmed condition, to said second position, wherein the fuze is in an armed condition permitting the firing pin to strike the detonator by impact of the fuze on a solid target and the fuze, if not activated by impact while in the armed condition, is returned to the unarmed condition by reversion of said bimetallic spring on cooling.