Penetrating ordnance safe and arming mechanism

Abstract

A test operable electro-mechanical safe and arming mechanism for hardened rget penetrating, and other, ordnance, not relying on stored energy, incorporating two mechanical interlocks and providing an electro-mechanical elapsed time reference and mechanical logic to check external control apparatus operation comprises a body having a reversible motor which drives a rotatable shaft having ends threaded in opposite directions. The shaft penetrates the threaded holes of three members which move axially depending on the direction of shaft rotation. The middle member is an initially misaligned explosive train component configured to engage one threaded shaft end to advance into the aligned or armed position. A ball interlock maintains this component misaligned until ordnance delivery is sensed at which time motor energization occurs in a first direction to cause shaft rotation and to preposition the mechanism for arming. Subsequent motor energization causes shaft rotation in the opposite direction which allows the misaligned member to engage one threaded shaft end and advance to the armed position. The shaft threads block this member's advance until the member is pushed against and engages the threads which must be cooperatively rotating. A spring arrangement which is prepositioned by the initial motor energization provides the force to cause the engagement of the member and the threads.