Image Number 3 for United States Patent #4691635.
A spherical safety rotor of a fuse of a spinning projectile comprises a recess to lock the rotor into its safety position. A retaining chamber for a detonator includes opposing orifices on the spherical surface. Cut-outs are provided in the rotor periphery to reduce the mass of the rotor. The cut-outs are arranged so that no portion thereof overlies a detonating chamber when the rotor is in its safety position.