A hydraulic circuit for a construction machine which operates an actuator for working machine simultaneously with an actuator for working element without degrading the operation of the actuator for working machine. The hydraulic circuit comprises a first hydraulic pump, a first directional control valve...http://www.google.se/patents/US4875337?utm_source=gb-gplus-sharePatent US4875337 - Construction machine dual-dump hydraulic circuit with piloted arm-boom cylinder supply priority switching valves
