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. 31, 1981
Filed:
Feb. 06, 1979
Toyota Jidosha Kogyo Kabushiki Kaisha, Toyota, JP;
Abstract
A hydraulic tappet is used in a variable valve lift engine. The tappet comprises an outer case having a pressure chamber formed therein, an inner case having an oil chamber formed therein and engaged within the outer case, and a check valve disposed between the pressure chamber and the oil chamber. The pressure chamber is communicated with an electromagnetic valve via an additional check valve. The electromagnetic valve is actuated in accordance with changes in operating conditions of an engine, i.e. the engine load and the temperature of the engine, so that the oil pressure between the additional check valve and the electromagnetic valve is maintained at a predetermined level. As a result, the valve lift of the engine can be varied at an optimum level in accordance with changes in the operating conditions of the engine.