Metal cutting machine with reciprocating head - uses hydraulic circuit with restrictor valve to give fast and slow movements

摘要

A saw blade is mounted on ahead sliding on a column. Rotation of the head is presented by an extension of the head and another column. The head is moved by a double acting pneumatic actuator on top of the machine with a speed controlled by a hydraulic circuit and a restrictor valve. The head initially moves rapidly downward, a sleeve sliding along the actuator piston rod. After this rapid movement the piston is pushed downwards in the cylinder, and fluid flows from beneath the piston via a conduit and restrictor valve to above the piston. This gives a slow cutting movement. A rapid return stroke is permitted by a flap valve on top of the piston.