Abstract: A control valve is disclosed for use in controlling flow of hydraulic fluid from a hydraulic pump to a plurality of actuators. The control valve includes a valve housing within which are formed control bores, pressure-compensating bores, a feed passage communicating between the pressure-compensating bores, a selected-load pressure transmitting passage communicating between the pressure-compensating bores, a pair of return passages communicating between the control bores and a reservoir tank, control passages communicating respectively between each of the control bores and each of the pressure-compensating bores, and feeding and exhausting passages, as well as actuator ports, communicating between the control bores and the actuators. Control valve spools are slidably mounted, respectively, in the control bores, and pressure-compensating valves are slidably mounted, respectively, the pressure-compensating bores.

Abstract: A spool type directional control valve switches flow of oil discharged from an oil hydraulic pump to a hydraulic actuator, and decreases internal leak of a cylinder. Two sets of separated cylinder passages are formed on a valve body provided with a main spool, and a nonleak valve is provided across them. The nonleak valve is equipped with a main passage switching puppet having a throttle on the nose, a spring for energizing it to a close side, a pilot poppet for controlling pressure of a spring chamber in which the spring is enclosed, and a piston for operating the poppet.

Abstract: In a shuttle valve device, a device body is formed by a single block in order to simplify construction. The device body is formed with a communication passage extending straight. A plurality of fitting bores are intersected with the communication passage. Each fitting bore extends straight from an outer surface of the block toward the communication passage. The fitting bore is intersected with the communication passage and has a forward end portion extending beyond the communication passage. The forward end portion serves as a pressure introducing section. Shuttle valves are inserted respectively in the fitting bores so as to divide the communication passage into a plurality of sections. Each shuttle valve compares pressure introduced through the passage section on one side of the shuttle valve with pressure introduced through the forward end portion of the fitting bore, to select one of the pressures and to lead the selected pressure to the passage section on the other side of the shuttle valve.

Abstract: A system for managing milking-cows in stanchion stool for milking by which a cow is situated on a floor with her body being fixed in a standing position by supporting members and her neck being restricted in vertical movement by means of stoppers, with teatcups rising on the floor between the cow legs and fitted to her teats. The teatcups are individually set in predetermined positions, according to the peculiar teat positions of the cow.