Abstract: Upper and lower separate pistons confining a constant volume of liquid in upper and lower chambers separated by a horizontal partition. A valve closing an aperture in the partition and opened by liquid in upper chamber moving to lower chamber when upper piston is pushed downwardly, the lower piston being moved downward by the liquid thus added to lower chamber. Orifice in valve permitting coil spring on lower piston to slowly raise lower piston and thereby return liquid from lower to upper chamber while valve is closed and downward push is absent from upper piston. A normally-open switch in electric fuze circuit, closable by lower piston upon attainment of a predetermined downward displacement, the upper piston being downwardly pushable through a one-way clutch by a plunger downwardly pushable by an external force and upwardly returned by an internal coil spring.

Abstract: A plurality of radio frequency shielded electrical break wire sensors for a issile fuze circuit are peripherally positioned on the circumferential outer surface of a warhead body. A first wire sensor provides an electrical indication of contact of the warhead outer surface with a target structure and initiation of the fuze electronics in response thereto. A second printed wire sensor is operatively positioned underneath the first sensor to provide an electrical indication of an impending break-up of the warhead body structure and initiation of the missile fuze.