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. 29, 2014
Filed:
Jun. 23, 2010
Masaki Sugiyama, Numazu, JP;
Toshihiro Tomita, Numazu, JP;
Masaki Kurimoto, Numazu, JP;
Hiroshi Kubota, Numazu, JP;
Tetsuya Hasegawa, Numazu, JP;
Masaki Sugiyama, Numazu, JP;
Toshihiro Tomita, Numazu, JP;
Masaki Kurimoto, Numazu, JP;
Hiroshi Kubota, Numazu, JP;
Tetsuya Hasegawa, Numazu, JP;
Makita Corporation, Aichi, JP;
Abstract
A lubrication apparatus for a four-stroke engine that prevents lubrication failure from occurring around the crankshaft and reliably prevents oil from remaining in a valve operating chamber includes: an intake part positioned below the level of an oil A in an oil reservoir even if the oil reservoir is tilted and the level of the oil A changes; an oil feeding passageway that sucks up the oil A from the intake part and supplies the oil A to the crank chamber; and an direct passageway that allows communication between a valve operating chamber and a crank chamber when a negative pressure is created in the crank chamber. Open end parts of the oil feeding passageway and the direct passageway which are open in the crank chamber are provided to open as the piston moves from a position near the top dead center to the top dead center.