Patent ID: 6877417

Claim:
A hydraulic circuit including: one directional control valve adapted to receive hydraulic fluid from a pressurized fluid source and control the direction of the flow of the hydraulic fluid by shifting the position of said directional control valve; one hydraulic actuator adapted to be operated by an external load or hydraulic fluid, of which the direction of the flow is controlled by the said directional control valve; a regeneration valve for opening or closing off a passage that connects the fluid-returning side and the fluid-feeding side of said hydraulic actuator operated by an external load; a pressure detector for detecting load pressure applied to said hydraulic actuator; at least one other directional control valve adapted to receive hydraulic fluid from the pressurized fluid source and control the direction of the flow of the hydraulic fluid by shifting the position of said other directional control valve(s); at least one other hydraulic actuator adapted to be operated by hydraulic fluid, of which the direction of the flow is controlled by said other directional control valve(s); and a controller that is adapted to, upon detecting the load pressure to said one hydraulic actuator to be low by means of said pressure detector, shift said one directional control valve to the neutral position, thereby interrupting the flow of the hydraulic fluid to said one hydraulic actuator, and simultaneously control the regeneration valve to be open.