(Fig. 6)

The fuze is of the igniferous type with a combined graze and direct action mechanism and an optional delay setting device which produces a 0.3 second delay. In conjunction with a gaine it is used in the H.E. shell, "K.Gr. 39" in the the 17 cm K in Mrs.L. equipment (a 17.25 cm gun on the 21 cm howitzer mounting).

Constructed mainly of steel, the portion protruding from the shell is coned with a flat top and is closed at the nose by a brass disc. The designation, "A.Z. 35 K" is stamped near the base of the coned head and, diametrically opposite, is a delay setting plug with set-ting marks lettering "M" and "O" stamped adjacent to it on either side. The overall length of the fuze is 4.94 inches and the weight 2 lb. 3 oz. 5 dr. The portion which is exposed when in the shell protrudes to a length of 3 inches.

The fuze body is screwthreaded externally for insertion in the shell and below the thread it is reduced in diameter and has a side aperture for the assembly of a centrifugal bolt attached to a shutter. The aperature is closed by a plate secured by a screw. Above the threaded portion a flange is formed which is coned to match the head. Above the flange the body is reduced in diameter and screwthreaded externally to receive the head. The delay setting plug, engraved with an arrowhead, is secured in a radial hole in the flange and on its inner end has an eccentric projection which bears on the upper end of the shutter locking bolt. The body is recessed from the base to accommodate the delay ar-rangement with a perforated pellet of gunpowder and is closed by a screwed plug with a central flash hole. Two flash channels in the top of the recess communicate with an up-per recess containing a steel graze pellet carrying the detonator. This recess is enlarged near the top to form a platform for five pivoted centrifugal segments of aluminium. The segments are held in a position to overlap a shoulder on the graze pellet by an expanding spring ring surrounding them. The needle, carried in a cylindrical pellet of aluminium, is supported above the graze pellet by a spiral creep spring, the pellet being kept in aligne-ment with the wooden hammer in the fuze head by a steel sleeve which fits over and protrudes above the pellet. The pellet and sleeve are accommodated in a central hole in a screwed plug which closes the top of the upper recess.

The delay holder consists of an aluminium cylindrical pellet with a flash channel through the centre, and a second channel, displaced from the centre, which contains a pressing of delay composition. A guideway of the shutter is cut in the top of the pellet and ex-tends beyond the central open flash hole. The figures "0,30"  (indicating a delay of 0.3 seconds) are stamped in the base of the holder. A thin disc of tin placed over the top of the holder has two perforations which correspond with the holes in the holder and is cut away to permit movement of the centrifugal bolt.

The shutter consists of a copper plate which fits in the guideway on the delay holder and is connected at its outer end to a centrifugal bolt. The bolt is pressed towards the centre of the body by a spiral spring held between the outer end of the bolt and a ring shaped recess in the plate closing the aperture in the side of the body. The shutter lock-ing bolt is contained in a vertical channel between the top of the aperture and the top of the body and consists of a solid cylindrical pellet of steel with a stem at its base. A spiral spring surrounding the stem supports the pellet, the upper end of which is engaged by the eccentric projection on the inner end of the delay setting plug.

When delayed action is required the delay setting plug is turned so that the arrowhead engraved on its head is set to the "M" graduation on the flange. At this setting the ec-centric on its inner end is lowered and the shutter locking bolt is pushed, against its spring, down into the aperture in the side of the fuze body, thus preventing the centrifu-gal bolt from moving outwards. For nondelay action the plug is set to the "O" graduation. The eccentric is then in the raised position and the shutter locking bolt is clear of the path of the centrifugal bolt.

During flight the coil of the expanding spring rings is enlarged and the segments swung clear of the graze pellet by centrifugal force. When set for non-delay the centrifugal bolt is also thrown outwards, taking with it the shutter and thus exposing the open flash hole in the centre of the delay holder. If set for delay the centrifugal bolt is held by the lock-ing bolt and only the channel containing the delay composition is exposed. During the pe-riod of deceleration, "creep" of the graze pellet is prevented by the creep spring. On gra-ze the pellet, overcoming the spring by its momentum, moves forward and the detonator is pierced by the needle. When suitable impact is obtained, the hammer, and conse-quently the needle, are driven at the same time as the pellet moves forward and direct action results. The path of the flash from the detonator to the magazine is governed by the setting. If set for delay, the empty channel in the delay holder is masked by the shutter and the path is through the channel containing the delay composition. If set for non delay the flash passing through the exposed empty channel will reach the magazine first.

Fig. 6