EMPLOYMENT: 15-cm Raketen Granate. (See fig. 612.)

DESCRIPTION: This is a direct action base fuze used in the 15-cm H.E. rocket. It may be identified by the stamping "Bd.Z. DOV" in the base. The over-all length of the fuze is 1.4 inches and its maximum diameter, over the threads, is 1.75 inches.

The fuze consists of a steel body, steel striker, five centrifugal segments of light alloy, expanding spring ring, creep spring, steel detonator holder, igniferous detonator and steel screwed plug. All steel components are rustproofed.

The body is screwthreaded externally with a left-hand thread for insertion in the base of the rocket, and the forward end is reduced in diameters screw-threaded for the attach-ment of the detonator holder. It is bored centrally from the front two diameters to form chambers to house the middle pellet and centrifugal segments. The neddle is integral with the inertia pellet, the pellet is housed in the base of the body, and provided with two shoulders below the needle, which is located centrally in the large chamber.

The five centrifugal segments are pivoted on this and are shiped so that one locks the other. In the unarmed position, the segments engage the plunger shoulder of the striker pellet and hold the striker off the detonator. They are surrounded and retained in this position by an expanding spring ring.

The spiral creep spring surrounding the striker held between the smaller shoulder of the striker pellet and a seating in the detonator holder.

The detonator holder is bored centrally to form a chamber, which are connected by a coned ring with a seating for one end of the creep spring. The larger chamber is screw-threaded to  receive the forward end of the fuze body. The larger chamber houses an igniferous detonator and is closed by a perforated screwed plug secured by stabbing.

ACTION:

Before Firing. The striker is held off the detonator by the centrifugal segments which are retained in the closed position by the expanding spring ring.

During Flight. On deceleration and when the necessary rotational velocity is reached, the segements, overcomming the spring ring, swing outwards under centrifugal force, clear of the striker pellet. Creep action by the striker pellet is prevented by the creep spring.

On impact or graze, the pellet moves forward, compressing the creep spring and carries the striker on to the detonator.

Figure 612 – Bd.Z. DOV