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. 01, 2003
Filed:
Mar. 30, 2001
Gordon E. Rado, Brookfield, WI (US);
Leonard E. Gescheidle, Rhinelander, WI (US);
Tecumseh Products Company, Tecumseh, MI (US);
Abstract
A four-stroke internal combustion engine includes a cylinder block including a cylinder therein and having a piston reciprocally disposed within the cylinder. A piston is operably engaged with a crankshaft. At least one intake valve is reciprocally driven by a camshaft. At least one exhaust valve is reciprocally driven by the camshaft. A vacuum release mechanism includes an operating member reciprocally supported within the camshaft for translation along an axis. A centrifugally actuated flyweight member is engaged with the operating member, wherein rotation of the camshaft above engine cranking speeds causes the flyweight member to move the operating member from a first position to a second position. A vacuum release member is movably supported within the camshaft and is in engagement with the operating member wherein translational movement of the operating member causes movement of the vacuum release member. The operating member and flyweight are urged to the first position at engine cranking speeds and moved by the flyweight member through centrifugal force to the second position at engine running speeds. The vacuum release member is in lifting engagement with one of the valves at the first position during at least a portion of the power stroke of the piston and out of lifting engagement with one of the valves at the second position.