Abstract: A compressed air valve circuit actuated assembly for operating a rotary tool turret of a lathe is disclosed which includes an actuator movably disposed in a housing and fixedly connected through an opening to the turret. The actuator moves linearly between a recessed position, wherein a first actuator attached ring of spaced apart teeth is closely intermeshed with a second housing attached ring of identical teeth, and an advanced position wherein the rings are decoupled to permit turret and actuator rotation. A series of compressed coil springs confined between the actuator and housing biases the actuator toward the recessed position. Compressed air supplied from the circuit to a housing chamber moves the actuator to the advanced position in opposition to the springs. A cross-piston, disposed in a bore formed in a housing surface portion and movable between start and ending positions, is coupled by an indexing pin to a slot in the actuator only when the actuator is in the advanced position.