EMPLOYMENT: Mechanical Impact Fuze used in Hollow Charge shells (See fig. 574.)

DATA:

Over-all length: 1.125 inches.

Maximum diameter: 0.937 inch.

Threaded length: 0.25 inch.

Number of threads: 7 RH.

CONSTRUCTION: The body of the fuze is screw-threaded externally to 0.69 inch gage with a pitch of approximately 1 mm for insertion in the shell. A recess formed in the un-derside is screw-threaded to receive the magazine which contains a 6.2-grain filling PETN under a 5.9-grain detonator of lead azide/calcium silicide 65/35. The upper part of the body is recessed to accommodate six pivoted centrifugal and threaded internally to re-ceive the aluminum head of the fuze. A central channel is formed between the upper and lower recess for the striker.

The steel striker is carried in an aluminum pellet supported by the centrifugal segments which are retained in the supporting position by an expanding spring ring.

The aluminum head of the fuze is recessed in the underside to accommodate the striker pellet and recessed at the nose to take the hammer which passes through a hole in the diaphrahm between the recesses. The hammer is of wood and rests on the head of the striker pellet. The recess containing the hammer is closed at the nose against air pres-sure by an aluminum disk sealed with a fillet of synthetic resin.

ACTION: During fligth, the coil of the expanding spring ring is enlarged and the segments rotated clear of the striker pellet by centrifugal force. The striker is then held off the diameter by the creep action resulting from deceleration. On impact, the hammer and striker are driven in and the detonator is pierced. The impulse setup by the detonation is communicated through the aluminum tube in the shell to the gaine in the base of the shell cavity. The construction of the detonator in th gaine is such that is could be initia-ted either by a flash or a pressure gaine.

Figure 574 – A.Z. 38