EMPLOYMENT: Use in H.E. shell "K.Gr. 39" in the 17-cm Mrs.L. equipment. (See fig. 582.)

DATA:

Over-all length: 4.937 inches.

Maximum diameter: 2.312 inches.

Threaded length: 0.5 inch.

Number of threads: 4 RH.

CONSTRUCTION: The fuze is of the igniferous type with a combined graze and direct ac-tion mechanism and an optional delay setting device which produces a 0.3-second delay.

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 disk. The designation "A.Z. 35 K" is stamped near the base of the cone head. Diametrically opposite is a delay setting plug with setting marks lettered "M" and "O" stamped adjacent to it on either side. The over-all length of the fuze is 4.94 inches and the weight 2 pounds 3 ounces 5 drams. The portion which is exposed when in the shell protrudes to a length of 3 inches.

The fuze body is screw-threaded 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 shuttler. The aperture 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 screw-threaded externally to receive the head. The delay setting plug, engraved with an arrowhead, is screwed into 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 arrangement with a perforated pellet of gunpowder, and is closed by a screwed plug with a central flash hole. A flash channel in the top of the recess communicates with an upper recess containing a steel graze pellet carrying the detonator. This recess contains a steel graze pellet carrying the detonator. This recess is enlarged near the top to form a plat-form for five pivoted centrifugal segments of aluminum. The segments are held in a position to overlap a shoulder on the graze pellet by an expanding spring ring surrounding them. The striker, carried in a cylindrical pellet of aluminum, is supported above the graze pellet by a spiral creep spring, the pel-let being kept in alignment 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 aluminum cylindrical pellet with a flash channel through the center and a second channel, displaced from the center, which contains a pressing of delay composition. A guideway for 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 se-cond) are stamped in the base of the holder. A thin disk of tin placed over the top of the holder has two perforations which correspond with the hole in the holder and is cut away to permit movement to 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 center of the body by a spiral spring held between the outer end of the bolt and ring-shiped 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 hammer end of the delay setting plug.

ACTION: When delayed action is required the delay setting plug is turned so that the arrowhead engraved in its head is set to the M graduation on the flange. At this setting the eccentric on its inner end is lowered and the shutter locking bolt is pushed, against this spring, down into the aperture in the side of the fuze body, thus preventing the centrifugal bolt from moving out-wards. For nondelay action the plug is set to the O gra-duation. 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 ring is enlarged and the segments swung clear of the graze pellet by centrifugal force. When set for nondelay, the centrifugal bolt is also thrown outwards, taking with it the shutter and thus ex-ploding the open flash hole in the center of the delay holder. If set for delay, the centrifugal bolt is held by the locking bolt. During the period of deceleration, "creep" of the graze pellet is prevented by the creep spring. On graze, the pellet overcoming the spring by its momentum, moves forward and the detonator is pierced by the striker. When suitable impact is obtained, the hammer, and consequently the striker, is driven in at the same time as the pellet mo-ves 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 nondelay, the flash passing through the exposed empty channel will reach the magazine first.

Figure 582 – A.Z. 35 K