EMPLOYMENT: Base fuze for the 3.7-cm Stick Bomb (3.7-cm Stiel Gr. 41). (See fig. 601.)

DATA:

Over-all Length: 1.65 inches.

Maximum Diameter: 1.0 inch.

Threaded Length: 0.25 inch.

Number of Threads: 5 RH.

CONSTRUCTION: The fuze is used in the 3.7-cm Pak, hollow charge, muzzle stick bomb and is of the igniferous type with a graze action. The designation of the fuze "Bd.Z. 5130" is stamped in the base. The weight of this fuze is 4 ounces 12 drams.

The body of the fuze is cylindrical with a threaded portion of reduced diameter at the head for insertion in the bomb. A large recess formed from the head, contains the graze pellet and is closed at the top by the detonator holder. A smaller recess near the peri-phery is formed from the base and contains a detent supported by a sprial spring. This recess is closed at the base by a disk secured by the turned over metal of the body. A channel, with a downward incline towards the side is drilled from the exterior of the body, through the recess containing the detent and into the recess containing the graze pellet. A ball which engages a shoulder on the graze pellet is held in this channel, bet-ween the two recesses, by the detent. Two key flats are formed near the base end of the body.

The graze pellet consists of a solid cylindrical pellet fitted with a striker at the head. An inclined shoulder, with which the ball engages, is formed below the head. A helical spring is held between the head of the pellet and the base of the detonator holder, the smaller end of the spring fitting around the striker.

The detonator holder consists of a flanged cup with a flash hole in its base and contains an igniferous detonator stamped with the number "26". The detonator is retained by the mouth of the cup being turned in to overlap a washer. The holder is supported at its flange by a step formed in the top of the recess and is secured by turned in metal of the body.

The detent is a solid cylindrical pellet with a concave head and a short stem at the base around which the upper end of sprial supporting spring is positioned.

ACTION: During transport the graze pellet is held away from the detonator by the ball which is held in contact with the shoulder on the pellet by the detent.

On acceleration the detent, overcoming the spring, sets back and thus releases the ball which moves down the inclined channel and leaves the graze pellet held off the detona-tor only by the helical creep spring. The concave head of the detent is apparently desig-ned to receive the ball when the detent rises again so as to push the ball up into the top of the recess.

On graze, the pellet moves forward, compressing the creep spring and the striker pierces the detonator.

Figure 601 – Bd.Z. 5130