Abstract: The invention relates to a hydraulic ratchet wrench with a double-action hydraulic cylinder piston drive with a gear pump (20) and a piston pump (21). According to the invention, a working stroke and a return stroke are controlled through a reversal of rotational direction of a pump motor (4), whereby the necessary flow volume is produced automatically via internal flow control valves, and without additional valve controls.

Abstract: In the test of a memory all data bit of fail data, which is output from a logic comparator, are stored in a failure analysis memory AFM; and at the time of recovery processing, bit designating data for designating plural bits in the fail data are read out of a bit designating memory 21D, the read-out bit designating data is used to take out of gates 21B-0 to 21B-N?1 the designated bits in each fail data read out of the failure analysis memory AFM, these pieces of bit data thus obtained are ORed, and based on the result of ORing, the recovery analysis processing.

Abstract: The invention relates to a hydraulic ratchet wrench with a double-action hydraulic cylinder piston drive with a gear pump (20) and a piston pump (21). According to the invention, a working stroke and a return stroke are controlled through a reversal of rotational direction of a pump motor (4), whereby the necessary flow volume is produced automatically via internal flow control valves, and without additional valve controls.