(Fig 30)

The fuze is of the detonating type with a direct action of the floating needle type and is used in 2-cm shell.

The head of the fuze which screws on to the body is recessed at the front end to ac-commodate the hammer. The recess has a central hole through which the stem of the hammer passes and is closed against air pressure at the front by a metal disc. The ham-mer consists of a disc with a stem which aligned with the needle in the fuze body.

The body is screw-threaded externally behind the flange for insertion in the shell and has an internal left-hand screw-thread for the magazine. A channel is formed through the centre of the body for the needle, the channel being of larger diameter at the front end to receive the head of the needle on functioning. A centrifugal safety slide, shaped to fit the stem of the needle below the enlarged head, is retained in the safe postion in its slot by a detent carried in the body. The detent is contained in a sleeve which screws into a recess in the fuze body and is supported in contact with a chamfered portion of the safety slide by a pellet of gun-powder at its base. A flash channel in the recess behind the powder pellet leads to another recess containing a detonator held off a striker in the base of this recess by a spiral spring. The detonator contains a mixture of potassium chlorate and antimony sulphide topped with black powder. A similar empty recess is for-med diametrically opposite in the fuze body; this is probably intended to preserve the balance of the fuze and to divert some of the pressure produced by the functioning of the detonator in the connected recess. Both recesses are closed at the front end by metal discs.

The magazine contains approximately 7 grains of P.E.T.N. in powder form and is closed by a detonator pressed in at the front end. The detonator contains about 15 grains of a mixture consisting of lead azide and calcium silicide topped with P.E.T.N.

On acceleration the detonator in the recess sets back against its spring and is pierced by the striker. The flash passes through the channel to the detent recess and ignites the gunpowder pellet thus depriving the detent of this support. Centrifugal force, set up by the rotation of the projectile and fuze, causes the slide to move outwards, away from the needle head, the chamfered end of the slide depressing the detent as this movement occurs. During flight "creep" action and the protection from air pressure provided by the metal closing disc at the nose results in a forward movement of the hammer and needle. On impact the needle is driven into the detonator by the hammer and thus brings about the detonation of the magazine.

Fig. 30

GERMAN FUZE A.Z. 1501