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:
Sep. 27, 2011
Filed:
Aug. 12, 2009
Kazuo Iwata, Yokohama, JP;
Noritoshi Takamura, Yokohama, JP;
Jun Tominaga, Yokohama, JP;
Norihiro Tajima, Yokohama, JP;
Takeshi Yabushita, Yokohama, JP;
Kazuo Iwata, Yokohama, JP;
Noritoshi Takamura, Yokohama, JP;
Jun Tominaga, Yokohama, JP;
Norihiro Tajima, Yokohama, JP;
Takeshi Yabushita, Yokohama, JP;
NHK Spring Co., Ltd., Yokohama-Shi, JP;
Abstract
A port is formed in a cylinder head of an engine. The port is opened and closed by a valve. A valve spring device is provided with a first spring and a second spring. The second spring is contained in a housing and held by a stopper in a manner such that it is compressed along an axis or subjected to a preload. The preload of the second spring is larger than an installation load of the first spring. An axial load acts on the springs. The valve spring device has load-deflection characteristics such that only the first spring deforms axially when the axial load is not larger than a predetermined value and that both the first and second springs deform axially when the axial is load exceeds the predetermined value.