Hydraulic press tool e.g. hand-operated press tool, has piston retracted to initial position by moving return valve into open position, where return valve is displaced by mechanical effect by rotating portion of hand lever around axis

摘要

The tool (1) has a pump pumping hydraulic fluid into a hydraulic cylinder (4) in which a hydraulic piston is movable between an initial position and a pressing position. A return valve is temporarily moved in an open position such that back flow of hydraulic fluid into a hydraulic fluid supply tank (7) is enabled when reaching a predetermined pressure of the hydraulic fluid. The hydraulic piston is retracted into the initial position by moving the return valve into the open position. The return valve is displaced by a mechanical effect by rotating a portion of a hand lever (3) around a longitudinal axis (L).