Pneumatic manual screwdriver device with motorized piston and screw jaws

摘要

The forward movement of the pneumatic screwdriver piston (3) is braked down where it reaches the head (26) of the screw fed into the clamping jaws (6). The device comprises an axially adjustable fixed endstop formed from a second piston (10) arranged in a forward second cylinder. A forward cylinder chamber (9) is bounded by an axially positionable adjuster ring (11) and an axial extension (14) of the second cylinder piston is contoured to fit into and engage the ring. The specified forward movement ends just before the compressed air feed line (18) reaches the motor power air inlet (20). In a variant, the device presents a spring cocked against its seat by the first forward movement. This seat forms part of a second piston to the rear of the first and in a second similarly rear cylinder.