Over-all length

Maximum diameter

Thread diameter

Markings

This is an aluminum fuze. In the body is a brass container which holds the clock mecha-nism composed of a train of four wheels and an oscillator. Passing through the body of the fuze is a centrifugal safety bolt which is fitted with a slot. This centrifugal bolt is also fitted with teeth which engage the teeth of the first wheel in the train series. Pass-ing through the center of the brass container is a firing pin with a collar at its midpoint. The firing pin is kept in the upward position by the collar resting on the top of the centri-fugal safety bolt. In the lower part of the fuze is the detonator holder, which is fitted on the outside with ball bearings which bear against the brass ring. Below the detonator holder is a spring under compression. Screwed into the base of the fuze is a booster.

When the projectile is fired, setback prevents the centrifugal bolt from moving outwards. After the setback forces have been overcome, centrifugal force will cause the centrifugal safety bolt to move outwards under the control of the train of wheels. In the event of the projectile's hitting a target, the firing pin will be driven onto the detonator, the collar being sheared. In the event that the projectile fails to hit a target, after the centrifugal bolt has been fully withdrawn, the detonator holder will move upwards under the action of its spring, the detonator then striking the firing pin. The function of the ball bearings appears to be to act as a friction-reducing device.

Figure 213
Percussion Nose Fuze for 37/54 H.E. Shell