1. The combination with a projectile casing having a central longitudinal spin axis, of a fuze therein including a timer escapement mechanism sensitive to spin and acceleration forces acting along said axis, a cylindrical housing for said fuze, an annular-ring ball bearing surrounding said fuze housing within the projectile casing, said ball bearing comprising a radially inner ball race connected with the fuze housing, a radially outer ball race connected with the projectile casing, and a continuous annular ring of ball elements therebetween, a first deformable thrust ring supporting the outer ball race in connection with said projectile casing, means providing a central thrust bearing for said fuze housing and including a single large thrust ball having a central opening therethrough extending along the spin axis, a firing pin extending through said opening in said thrust ball and along said spin axis, a detonator element aligned with said firing pin within said projectile casing, and a second deformable thrust ring supporting said thrust bearing in connection with the projectile casing.

2. The combination with a cylindrical shell casing having a central longitudinal spin axis, of a fuze therein including a timer escapement mechanism sensitive to spin and acceleration forces along said axis, a rotatable cylindrical housing for said fuze, mounted in coaxial relation to said spin axis within the forward end of said casing, an annular-ring ball bearing surrounding said fuze housing within the said casing, said ball bearing comprising a radially inner ball race connected with the fuze housing, a radially outer ball race connected with the shell casing, and a continuous annular ring of ball elements therebetween, a first deformable metallic thrust ring supporting the outer ball race in connection with said shell casing, means providing a central thrust bearing for said fuze housing and including a single larger thrust ball having a central opening therethrough extending along the spin axis, a spring retracted firing pin extending through said opening in said thrust ball and along said axis, a detonator element aligned with said firing pin within said shell casing, a circular carrier plate in a plane normal to the spin axis and centered thereon for holding said central thrust bearing, and a second deformable metallic-thrust ring supporting said thrust bearing through said carrier plate in connection with the shell casing.

3. The combination with a shell case having a central longitudinal spin axis, of a fuze therein including a timer escapement mechanism sensitive to spin and acceleration forces acting on the shell case along said axis on firing, a rotatable cylindrical housing for said fuze within and coaxial with said shell case, an annular thrust and radial ball bearing surround said fuze between said housing and the shell case for free rotational movement of said housing on said axis, said bearing comprising a radially inner ball race connected with the fuze housing, a radially outer ball race connected with the shell case, and a continuous annular ring of ball elements therebetween, a fixed annular supporting ring connected with the inner wall of the shell case in rear of said outer ball race, a first deformable metallic thrust ring directly engaging said outer ball race and seated on said thrust ring to provide a yielding supporting connection for said bearing and fuze housing within said shell case, means providing a central thrust bearing for said fuze housing and including a relatively large diameter single-thrust ball having a central opening therethrough extending along the spin axis, a firing pin operably connected with said escapement mechanism extending through said opening in said thrust ball along said spin axis, a detonator element aligned with said firing pin within said shell case, means providing a transversely divided central ball race for said central thrust bearing on said spin axis and connected with said shell case, and a second deformable metallic thrust ring supporting said central thrust bearing within the shell case.

5. A spin attenuator structure for a mechanical time fuze, comprising in combination, a cylindrical outer carrier casing subject to high spin rates on its longitudinal axis and to high setback forces of acceleration along said axis, a fuze having a cylindrical housing rotatably mounted on said axis in said casing and having a hollow interior, a timer escapement mechanism sensitive to said spin rates and setback forces mounted on said axis in said fuze housing, an elongated firing pin connected to be actuated by said escapement mechanism and extending rearwardly therefrom along said axis in a retracted position, an outer annular ring ball bearing interposed between the fuze housing and the interior wall of said carrier casing for free rotational movement of said fuze housing on said axis within the carrier casing, said ball bearing having radially inner and outer annular ball races, an annular supporting ring for the outer ball race of said annular ball bearing attached to the inner wall of the carrier casing, a first deformable thrust and spacing ring interposed between and separating the outer ball bearing race and the supporting ring for receiving and absorbing setback forces on said annular ring bearing from said fuze housing, an inner single-ball thrust bearing for said fuze housing mounted centrally and rearwardly thereof on said axis and including a single-ball element with the firing pin extending centrally therethrough, a fixed supporting wall for said single-ball thrust bearing extending transversely across and attached to said carrier casing, a circular carrier plate for said thrust bearing supported by said wall, a second deformable thrust and spacing ring interposed between and separating said wall and carrier plate for receiving and absorbing setback forces on said thrust bearing from said fuze housing, means providing a central pocket in said tRansverse supporting wall, and a detonator element in said pocket aligned with and spaced from the striker end of said firing pin in said retracted position.