Hydraulic-frictional system for rotating the arm of a forging manipulator

摘要

The arm of a forging manipulator has tongues at one end for engaging with a workpiece and is journaled for rotation about a horizontal axis. At the other end the arm carries a pair of clamps each of which has a pair of clamping jaws pivotally connected at one end and adapted to be spread apart or drawn against the arm by a spreading hydraulic cylinder at the other end of each pair of jaws. The cylinders are interconnected for reversing operation and are hydraulically linked to a pair of drive cylinders, the pistons of which are pivotally connected to the respective clamps so that one of the drive cylinders is effective to rotate the arm when its clamping cylinder draws its jaws against the arm while the other clamping cylinder spreads the other pair of jaws apart during the ineffective stroke of the drive piston.