The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 15, 1991
Filed:
Sep. 01, 1989
Wataru Kubomoto, Hiroshima, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
A control circuit for a hydraulic actuator which allows the hydraulic actuator to be operated readily without much skill and at a suitable speed in accordance with a load applied thereto. The control circuit includes a change-over valve provided intermediately of a pilot pipe line communicating with a pilot oil chamber of a hydraulic change-over valve which belongs to one of a pair of hydraulic change-over valve sets of a hydraulic operating circuit for the hydraulic actuator. The change-over valve is normally urged to a position wherein the pilot oil chamber of the hydraulic change-over valve is communicated with a tank, but is changed over, when a hydraulic pressure higher than a predetermined value acts upon a pilot oil chamber of the change-over valve, to another position in which the pilot oil chamber of the hydraulic change-over valve is communicated with the pilot pipe line. A branch pipe line branches from a pipe line for discharge oil under pressure of a hydraulic pump provided for supplying oil under pressure to the other hydraulic change-over valve set and is connected to the pilot oil chamber of the change-over valve.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile