Abstract: A self-powered fuze apparatus for a projectile containing an explosive charge which comprises a first housing containing a mechanical safety device for releasably preventing undesired movement of a detonator cup holder containing a detonator from an unarmed to an armed position wherein the detonator cup is shielded from the charge to be exploded in the unarmed position and the detonator cup communicates with the charge only in the armed position and the second housing adjacent the first housing containing an electronic safety means for sensing target impact and projectile launch and selectively passing a piezoelectrically generated firing current to the detonator cup only upon sensing a predetermined magnitude target impact only within a predetermined time after sensing the launch acceleration and only when the electronic means is electrically and mechanically connected to the detonator cup in the armed position.

Abstract: In the method of increasing the detonation energy in an electromagnetic fuze system of a low-acceleration projectile a detonator generator which is held in an inactive or rest position by an elastic force, is accelerated along a predetermined travel path in the rear portion of a housing at the onset of the firing acceleration. The detonator generator is accelerated such that the detonator generator impacts upon an impact body which is provided with a central bore. As a result, a reaction member of the detonator generator inactivates its mechanical safety device and is accelerated, thus providing the detonation energy. In the retarding phase the detonator generator is returned into its original position by means of the elastic force and thus is ready for detonation. In comparison to known methods and apparatus there can thus be dispensed with an external power supply, whereby safety is increased with respect to maintenance, tests and firing.

Abstract: The invention is directed to the provision of a safety device to prevent premature detonation of ammunition, particularly low spin projectiles of the type in which a primer pellet is positioned in a rotor which rotates from an unarmed to an armed position upon firing. The safety device is biased under the action of the spring to project into a groove in the rotor so as to be engageable with an end face of the groove. If the projectile is fired with normal acceleration, the resulting force will cause the safety device to become disengaged from the groove in the rotor against the action of the spring. If acceleration is below normal, the safety device will engage the rotor and lock it in an unarmed position. An inertial mass lock is also provided as an additional measure against accidental or premature arming of the projectile.