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:
Mar. 07, 1989
Filed:
Feb. 17, 1988
Eiichiro Kawahara, Saitama, JP;
Kenichi Ikejiri, Saitama, JP;
Takashi Iino, Saitama, JP;
Kenjiro Iwasawa, Tochigi, JP;
Noboru Yamamoto, Saitama, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An actuator has a pilot valve incorporated in a piston thereof which is slidably disposed in a cylinder tube, the piston having first and second piston lands slidably disposed in first and second coaxial cylinder chambers. A spool valve body has first and second spool lands slidably disposed in an inner hole in the piston. When the spool valve body is moved in one direction, a first axial passage in the piston communicates with a pressure sink through a first return port which is opened by the first spool land, and a second axial passage in the piston communicates with a portion of the inner hole in front of the second spool land through a second supply port which is opened by the second spool land. When the spool valve body is moved in the opposite direction, the second axial passage communicates with the pressure sink through a second return passage which is opened by the second spool land, and the first axial passage communicates with a portion of the inner hole in front of the first spool land through a first supply port which is opened by the first spool land. The spool valve body is movable under a differential pressure between two inlet ports. The pilot valve cam amplify the operating force on the piston even if the difference between applied input oil pressure is small. In addition, the actuator is compact in size.