Abstract: A controlling motor for moving a stem along an axis has a hydraulic actuator with a cylinder in which a piston that is frictionally linked to the stem is slidingly and sealingly mounted, as well as a compression spring that is frictionally linked to the stem and acts against the actuator. The controlling motor has a trigger with an inflow area into which hydraulic fluid may be introduced, a pressure area that communicates with the inflow area through a diaphragm and is connected to the actuator, and a drainage area from which the hydraulic fluid may be evacuated without pressure, as well as a switching element that links the pressure area to the drainage area when a positive pressure differential occurs between the pressure area and the inflow area, and that otherwise shuts off the drainage area. The stem may be pushed out of the cylinder by the compression spring and may be drawn into the cylinder when hydraulic fluid is applied to the inflow area.

Abstract: This actuating drive (1) for a control valve (2) has a control circuit which sets the actuating drive (1) to correspond with a specified required value from an overriding installation control system. It has, in addition, a main piston (6) sliding in a main cylinder (5) with a drive volume (7), on one side of the main piston (6), which can be acted on in a controlled manner by oil under pressure and has a plate valve (17) fitted upstream of the drive volume (7).The intention is to create an actuating drive, for a control valve, whose dynamic behavior can be improved by relatively simple means. This is achieved by the plate valve (17) being provided with a separate reservoir volume, connected to a drain appliance, for the oil emerging from the plate valve (17).

Abstract: An improved trigger valve for a pneumatic nailing machine is disclosed. A communication hole between the main air chamber and the pilot air chamber is made as small as possible. This allows the trigger valve to return in a delayed manner so that the head valve and driver piston operate properly.