Ball rotor safety and arming delay device

Claim 2

A safety and arming delay fuze for spinning munitions comprising a housing, a cavity in said housing, a ball rotor in said cavity having a polar moment of inertia larger than either transverse moment of inertia, a detonator within said ball rotor, a firing pin means in said housing, means to hold said ball rotor in a first safe position with said detonator out of alignment with said firing pin means and to release said ball rotor when said munition is launched, means for increasing arming distance by reducing substantially all friction forces between the walls of said cavity and the ball rotor, the latter means involves the use of a low viscosity liquid to exert a buoyant force on the ball rotor such that as the munition rotates after launch, the detonator revolves many times about the axis of the projectile and eventually spirals into alignment with the firing pin means thereby providing longer arming delays for the fuze with the revolving motion of the detonator being controlled primarily by the friction forces between the cavity and the ball rotor.

Claim 3

The invention in accordance with claim 1, wherein said liquid has a density greater than 1.4.

Claim 4

The invention in accordance with claim 1, wherein the nominal radial clearance between the ball and its housing is greater than 0.004 inches.

Claim 5

The invention in accordance with claim 1, wherein a boundary lubricant is mixed with said liquid to lower the coefficient of friction between the ball rotor and its housing.

Claim 6

The invention in accordance with claim 3, wherein said boundary lubricant is oleic acid.

Claim 7

The invention in accordance with claim 1, wherein the average density of the ball rotor is reduced through the inclusion of a low density material.

Claim 8

The invention in accordance with claim 6, wherein said material is a plastic.

Claim 9

A safety and arming delay fuze for spinning munitions comprising a housing, a cavity in said housing, a ball rotor in said cavity having a polar moment of inertia larger than either transverse moment of inertia, a detonator within said ball rotor, a firing pin in said housing, means to hold said ball rotor in a first safe position with said detonator out of alignment with said firing pin and to release said ball rotor when said munition is launched, means for increasing arming distance by supporting the ball within said cavity at set back on a small portion of the ball located near its initial spin axis and to delay the spin-up of the ball rotor such that the angular velocity of the ball rotor is substantially less than the angular velocity of the munition when the munition leaves its launch site such that as the munition rotates after launch, the detonator revolves many times about the axis of the projectile and eventually spirals into alignment with the firing pin thereby providing longer arming delays for the fuze.

Claim 10

A safety and arming delay fuze for spinning munitions comprising a housing, a cavity in said housing, a ball rotor in said cavity having a polar moment of inertia larger than either transverse moment of inertia, a detonator within said ball rotor, a firing pin in said housing, means to hold said ball rotor in a first safe position with said detonator out of alignment with said firing pin and to release said ball rotor when said munition is launched, means for increasing arming distance by supporting the ball within said cavity at set back on a small portion of the ball located near its initial spin axis and to delay the spin-up of the ball rotor such that the angular velocity of the ball rotor is substantially less than the angular velocity of the munition when the munition leaves its launch site such that as the munition rotates after launch, the detonator revolves many times about the axis of the projectile and eventually spirals into alignment with the firing pin thereby providing longer arming delays for the fuze.

Claim 11

A safety and arming delay fuze for spinning munitions comprising a housing, a cavity in said housing, a ball rotor in said cavity having a polar moment of inertia larger than either transverse moment of inertia, an explosive material within said ball rotor, firing means in said housing to ignite the explosive material, means to hold said ball rotor in a first safe position with said explosive material out of alignment with said firing means and to release said ball rotor when the munition is launched, means for increasing arming distance by reducing substantially all friction forces between the walls of said cavity and the ball rotor such that as the munition rotates after launch, the explosive material revolves many times about the axis of the munition and eventually spirals into alignment with the firing means thereby providing longer arming delays for the fuze with the revolving motion of the explosive material being controlled primarily by the friction forces at the point of contact of the cavity by the ball rotor, said arming distance increasing means involving the use of a liquid to exert a buoyant force on the ball rotor, said liquid having a density greater than 1.4.

Claim 12

A safety and arming delay fuze for spinning munitions comprising a housing, a cavity in said housing, a ball rotor in said cavity having a polar moment of inertia larger than either transverse moment of inertia, an explosive material within said ball rotor, firing means in said housing to ignite the explosive material, means to hold said ball rotor in a first safe position with said explosive material out of alignment with said firing means and to release said ball rotor when the munition is launched, means for increasing arming distance by reducing substantially all friction forces between the walls of said cavity and the ball rotor such that as the munition rotates after launch, the explosive material revolves many times about the axis of the munition and eventually spirals into alignment with the firing means thereby providing longer arming delays for the fuze with the revolving motion of the explosive material being controlled primarily by the friction forces at the point of contact of the cavity by the ball rotor, said arming distance increasing means involving the use of a liquid to exert a buoyant force on the ball rotor, said liquid having a density greater than 1.4.