EMPLOYMENT: Mechanical impact nose fuze for H.E. projectile in 20-28 and 42-28 tape-red bore guns. (See fig. 560.)

DATA:

Over-all length: 0.937 inch.

Maximum diameter: 0.687 inch.

Threaded length: 0.25 inch.

Number of threads: 6 RH.

CONSTRUCTION: Aluminium body with brass and bronze internal parts. Contains expand-ing centrifugal segments in a phosphor bronze spring and a movable striker and creep spring.

ACTION: Initial set-back of the steel ring causes the lip on ist lower edge to engage with notches on the centrifugal segments thereby keeping the segments from opening while the projectile is in the bore of the gun. This is a bore safety feature. After the projectile leaves the weapon, deceleration causes the steel ring to creep forward, disengaging the lip from the centrifugal segments. Centrifugal force causes the segments to expand the centrifugal spring so that on impact the striker may pass through the segments and pier-ce the primer.

Figure 560 – A.Z. 5072