Abstract: The invention relates to a fuze safety device (1) for an ammunition unit such as a projectile, shell, rocket or the like. The safe and armed conditions of the fuze safety device are defined by a movable slide or rotor member which takes a first position in safe condition and a second position in armed condition and cooperates with at least two locking elements (7, 8). Each locking element has its own condition for release and in their released positions they permit the movable member to assume its second position. The locking members (7, 8) are arranged to cooperate mutually in such a way that both of the locking elements are released when their release conditions occur in a first order but release of at least one of the locking elements is inhibited if release conditions occur in a second order.

Abstract: A safety and arming device for an ordnance fuze for use on projectiles exposed to thermal heating by the air friction. The device comprises arming means which influenced by the heating produced on the casing of the projectile are arranged to effectuate the arming function. The arming means comprises a bimetallic strip with one end contacting the casing of the projectile and one end free to move on heating. The movement is utilized to change the safety device from its first safe position to its second armed position.