Patent Number: 6,192,929

Title: Hydraulic controller

Abstract: The present invention provides a hydraulic controller comprising: a plurality of switching spools; a plurality of cylinder ports of a switching valve; a compressed oil passage common to the switching valves having an intermediate chambers, at least a check valve in correspondence with at least a part of said switching spools, and said check valve being positioned between said intermediate chambers and said cylinder ports, so that said switching spools being positioned in a neutral position to close said passage and also being movable to adjust opening degree of said passage, wherein auxiliary ports are provided between the cylinder ports and a tank line; flow rate adjusters are also provided between the auxiliary ports and the tank line for adjusting an opening degree of the passage; pressure detectors are provided in the switching valves for detecting pressures of oils in the intermediate chambers; a maximum pressure selector operatively linked to said pressure detectors for selecting a maximum pressure from the detected pressures by the pressure detectors; whereby the pressures of said intermediate chambers are applied to the flow rate adjusters in an opening direction, while the selected maximum pressure selected by said maximum pressure selector is applied to the flow rate adjusters in a closing direction.

Inventors: Matsumoto; Satoshi (Kanagawa, JP)

Assignee: Toshiba Machine Co., Ltd.

International Classification: F15B 13/04 (20060101); F15B 11/00 (20060101); F15B 13/00 (20060101); F15B 11/16 (20060101); F15B 013/08 ()

Expiration Date: 02/27/2018