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:
Feb. 16, 1999
Filed:
Oct. 21, 1997
Tadao Hasegawa, Toyota, JP;
Kiyoshi Sugimoto, Okazaki, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A valve drive device has a pair of valves in association with a cylinder and a pair of cams provided on the camshaft to selectively open and close the valves. Each cam has a cam surface and a cam nose. The cam surface has an axially varying radius at the cam nose. A bearing supports the camshaft between the pair of cams. A pair of valve lifters are arranged respectively between the cams and the valves. Each valve lifter has a supporting surface and a cam follower supported on the supporting surface to slidably contact with the cam surface. A moving mechanism moves axially to change the lift amount of the valves, Each cam follower is located farther from the bearing, which is positioned between the pair of cams, than the center of the supporting surface in the axial direction of the camshaft. This results in greater axial movement of the cams and a greater variation of valve lift without placing excessive axial lodes on the camshaft.