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:
Apr. 13, 1993
Filed:
Aug. 31, 1992
Hiroaki Imai, Kanagawa, JP;
Atsugi Unisia Corporation, Atsugi, JP;
Abstract
A valve timing control system includes a timing sprocket, a camshaft, a sleeve secured to the camshaft and accomodated within the timing sprocket. A helical piston assembly and a floating piston are movably disposed in an annular space between the timing sprocket and the sleeve. An end plug is disposed at one end of the timing sprocket to close one end of the annular space. First and second chambers are defined between the floating piston and the end plug and between the floating piston and the helical piston assembly, respectively. A valve spool is operatively connected to an actuator and movably disposed in the sleeve. The valve spool moves among first, second and third positions. At the first position, the first and second chambers are drained. At the second position, the first chamber is communicated with a hydraulic fluid pump and the second chamber is drained. At the third position, the first and second chambers are communicated with the hydraulic fluid pump.