Projectile used in

Over-all length

Maximum diameter

Thread diameter

Markings

This fuze is in the shape of a truncated cone with screw-threaded brass adapter at the base to screw into the nose of the projectile. The entire fuze, apart from the brass co-ver plate at the nose, is painted black. The outer casing is steel; the inner housing is aluminum; and the detonator holder is brass. The detonator holder is held in position by a creep spring resting against the clock mechanism. The clockwork is similar to that used in Nose Fuze for the 37/54 H.E. Shell. A centrifu-gal safety bolt is horseshoe-shaped and is fitted with teeth which engage the first wheel in the series of the clock mechanism. Another centrifugal bolt at ring angles to the safety bolt is fitted within a spring and locks the safety bolt in position. The firing pin is kept in upward position by a collar at its midpoint which rests on top of the centrifugal safety bolt. The striker fits into the outer casing and is not connected directly to the firing pin but is separated by a small connec-ting rod.

On firing, the centrifugal bolt immediately moves outwards, unlocking the horse-shoe centrifugal which is held by clock mechanism during acceleration, since friction set up between the comparatively large surface of the contact of the cog-wheels is sufficient to prevent outward movements of the bolt. On deceleration, however, the cogwheels set forward and separate, and allow the horseshoe centrifugal bolt to move outwards, re-leasing the firing pin which, however, remains in position because of deceleration. On im-pact with a soft surface, the detonator moves forward to hit the firing pin. On impact with a hard surface, the striker is forced down, hitting the connecting rod, which in turn causes the firing pin to hit the detonator.

The fuze OK. BO. SC. 41, differs in exterior appearance but functions exactly the same.

Figure 210
Percussion Nose Fuze OK. BO. SC. 41

Figure 211
Percussion Nose Fuze M16 (OK. 2S 912)