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:
May. 11, 1993
Filed:
Nov. 22, 1991
Katsuhiko Uchida, Kanagawa, JP;
Seiji Suga, Kanagawa, JP;
Atsugi Unisia Corp., Atsugi, JP;
Abstract
An intake- and/or exhaust-valve timing control system for an internal combustion engine comprises a timing belt pulley having a driven connection with an engine crankshaft, a camshaft journaled by a bearing member mounted on a cylinder head and receiving torque transmitted from the timing belt pulley, a ring gear mechanism for adjusting a relative phase angle between the timing belt pulley and the camshaft. The valve timing control system includes a first hydraulic circuit provided for drivingly controlling the ring gear mechanism via fluid pressure depending upon the operating state of the engine and a second hydraulic circuit provided for lubricating frictional surfaces between the bearing member and the camshaft. The first and second hydraulic circuits are separated from each other. The valve timing control system includes a directional control valve connected to the first hydraulic circuit for switching the direction of working fluid flowing through the first hydraulic circuit.