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:
May. 28, 2002
Filed:
Jan. 15, 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 having a cylinder therein and a piston reciprocally disposed within the cylinder. The piston is operably engaged with a crankshaft. At least one intake valve and one exhaust valve is reciprocally driven by a camshaft. A vacuum release mechanism includes an operating member rotationally supported by the camshaft and has an operator disposed thereon. A centrifugally actuated flyweight member is attached to the operating member, wherein rotation of the camshaft above engine cranking speeds causes the flyweight member to rotate the operating member. A vacuum release member is reciprocally supported by the camshaft and in engagement with the operator wherein rotational movement of the operating member causes radial translation of the vacuum release member through the operator. The operating member and flyweight member are urged to a first position at engine cranking speeds and rotated by the flyweight member through centrifugal force to a second position at engine running speeds. The vacuum release member is in lifting engagement with one of the valves at the first position during a portion of the power stroke and out of lifting engagement with the valve at the second position.