Patent ID: 8607674

Claim:
A torque-regulated manual drive hydraulic wrench for tightening and loosening, comprising: a casing ( 1 ); a manual drive lever ( 29 ) coupled to one end of the casing ( 1 ), and a power piston ( 2 ) coupled to the opposite end of the casing ( 1 ); a two-speed piston ( 14 ) within the casing ( 1 ); a closed-circuit, four-way distributor ( 48 ) within the casing ( 1 ); wherein the piston forward movement stroke ( 14 ) is carried out through the lever thrust ( 29 ), which is attached to a support ( 30 ), the support ( 30 ) pushing in turn a spherical, double-head connecting rod ( 15 ), which performs the function of ball over the piston ( 14 ); the piston forward movement ( 14 ) pushes a hydraulic fluid housed in a fluid accumulator ( 50 ), causing the hydraulic fluid to open the valves ( 13 , 13 C), and through a butt ( 16 ) hydraulic fluid is provided to a pressure valve ( 39 ), which urges a piston ( 7 ), that in turn pushes a power piston ( 2 ) causing it to mover forward; and wherein the backward movement of the piston is made by a distributor control lever ( 43 ), which is directed towards the drive lever ( 29 ) position, the distributor control lever ( 43 ) is coupled to a cam ( 49 ) which acts on a push rod ( 46 ) which in turn acts on the valve ( 13 ), at the same time it causes the valve seat support to move backwards ( 47 ), which results in the closing of the pressure circuit valve ( 13 ), which in turn opens the return circuit.