Abstract: A fuse is capable of installation in a warhead only when a rotor of the fuse is in its safety position. If the rotor is in its live position, installation in the fuse is not possible. The fuse comprises an installation safety element which is movable between a normal first position blocking installation of the fuse and a second position permitting such installation. In its live position, the rotor blocks movement of the element to its second position. When in its second position, the element does not interfere with movement of the rotor to a live position.

Abstract: A switch is adapted for use in a projectile for actuating an electrical explosives-igniter in response to impact of the projectile. The switch includes a stationary electrical contact and a movable electrical contact. An actuator moves the movable contact against the stationary contact to complete an electric circuit in response to projectile impact. The actuator comprises a ball movable toward the movable contact. The ball is seated in a conical recess to enable the ball to move toward the movable contact even when the projectile does not impact along its longitudinal axis. The movable contact may comprise a cone-like array of flexible arms which engage the ball; movement of the ball flexes one or more of the arms into engagement with the stationary contact. Alternatively, the movable contact may comprise a linearly movable bolt engaged by the ball. A movable weight may be positioned behind the ball and adapted to engage the ball upon projectile impact to urge the ball toward the movable contact.

Abstract: A projectile fuse comprises a rotor rotatable from a safety position to a live position. A slide is arranged to immobilize the rotor in its safety position. A piston is operably connected to the slide for displacing the slide to release the rotor for rotation. A conduit communicates one end of the piston with air pressure generated in response to firing of the projectile to shift the slide in a manner displacing the slide to release the rotor.