Werkzeugmaschinenfabrik Oerlikon-buhrle Ag

Robert Apotheloz

Georg Leutwyler

The dud de-arming device serves to de-arm a fuze of a projectile which has remained lying on the ground or the place where it landed as a dud in order to prevent the discovered dud from still exploding when touched or moved. As to spinning projectiles the dud de-arming device should de-arm the fuze after disappearance of the projectile spin and for spinless projectiles the dud de-arming device should de-arm the fuze after a certain time following the impact deceleration of the spinless projectile. The dud de-arming device comprises a rotor which can be rotated by spring force. This rotor can assume an armed or live position due to the projectile spin or by virtue of the firing acceleration. Upon disappearance of the projectile spin or by virtue of the impact deceleration the rotor should assume a de-armed or safety position.

Dud de-arming device or insert for a projectile fuze

It happens time and again that a fuze does not function and that the projectile remains in the field or the place where it landed as a dud. When such a dud is found the danger exists that it might explode upon the finder's touch or when moved or lifted. To prevent this danger the impact fuze in a dud should be able to de-arm itself in a non-explosive manner. This is achieved by positioning a dud insert or de-arming device between an explosive or firing train and a booster charge. This dud de-arming device contains an escapement device which after a predetermined delay time following impact of the projectile moves a rotor from its armed or live position into its de-armed or inert position. The dud de-arming device contains structure which, by virtue of the impact delay or deceleration, that is a delay in ignition of the booster charge upon the projectile hitting the target or ground, activates the escapement mechanism.

Projectile impact fuze containing de-arming device

A safety device for a fuze of a spinning projectile comprises a spin acceleration safety element and a firing forward acceleration safety element. The firing forward acceleration safety element contains a ball displaceable by the action of the firing forward acceleration. The spin acceleration safety element employs an escapement or delay mechanism including an asymmetrically structured balance wheel whose center of gravity is radially displaced from its pivot axis such that the escapement or delay mechanism can begin to operate and time out only after the spin acceleration has ceased to be effective.

Safety device for a spinning projectile fuze

The impact fuze is as light as possible and protects a time-delay device against preliminary destruction at impact of the projectile in or at the target in order that the projectile can penetrate as deeply as possible into or through a hard target, for instance a concrete wall, before the projectile is detonated. A steel housing is introduced into the interior of a light metal housing of the impact fuze in order to fulfill both of these requirements.

Impact fuze

A safety apparatus for a spinning projectile fuze comprises a rotor with which there is operatively associated a toothed segment which, under the action of the spin, drives a retarding or restraining mechanism and following expiration of the action of the retarding mechanism moves the rotor into its armed or live position. The safety apparatus further comprises a spin safety element and an acceleration-spin safety element. The acceleration-spin safety element contains a ball displaceable by the action of the firing acceleration, and a disc member, and the spin safety element possesses a piston displaceable by the action of the projectile spin in order to release the rotor.

Safety apparatus for a spinning projectile fuse

A blocking mechanism for an impact fuze comprising a spring-loaded blocking sleeve lengthwise displaceable in the fuze housing and provided with at least one radially movable blocking body. The blocking body can be brought by means of a spring-loaded blocking bolt lengthwise displaceable within the blocking sleeve into a position blocking the blocking sleeve in the fuze housing. The fuze housing has a recess into which there can engage the blocking body for blocking the blocking sleeve in a first position. The fuze housing has a further substantially wedge-shaped recess which tapers towards the rear in which there can be wedged the blocking body between a wall of this recess and the blocking bolt, in a second position of the blocking sleeve, for the purpose of securing the blocking bolt against displacement towards the rear.

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Greifensee, Switzerland

Robert Apotheloz