Description
The Navy Rocket Base Fuze Mk 31 is identical to the Navy Base Detonating Projectile Fuze Mk 31. This fuze is armed by centrifugal force and thus can only be used in spin stabilized rockets. The fuze is designed for instantaneous action on impact. It is shipped installed in the base of the rocket body.
The Base Fuze Mk 36 differs from the Mk 31 only in that it has a 0.01 second delay element housed in the space which is the flash channel in the Mk 31.
Functioning
The force of set-back causes the sensitive firing pin to move back on the firing pin detents and hold them in by friction. When the motor burns out. creep causes the firing pin to move forward and release the detents. Centrifugal force will move both sets of detents outward against their springs, and the fuze is then completely armed. The detonator plunger is prevented from moving forward on creep because of the anti-creep spring; but on impact the auxiliary plunger, acting as an inertia weight, pushes the detonator plunger forward. This action moves the inner cup forward, thus compressing the anti-creep spring, and brings the booster lead-ins and lead-outs in line. The sensitive primer in the top of the detonator plunger is carried on to the sensitive firing pin, and the explosion of the sensitive primer accomplishes two things:
1. The gases resulting from the explosion pass through the port holes on the side of the primer container and build up a high pressure, expanding that part of the cup which is adjacent to the holes in the nose cap. This action locks the detonator plunger in the fired position and keeps the firing train lined up.
2. The shear wire that has been holding up the secondary firing pin is broken, and the secondary firing pin is driven down into the secondary primer, and the flash sets off the detonator and booster elements.
Hazardous Components
No information about hazardous components.
See Also
Source(s)
OP 1664, Volume 1 - US Explosive Ordnance (1947)
