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. 01, 2000
Filed:
Aug. 05, 1998
Ronald Jay Pierik, Rochester, NY (US);
John Castellana, Fairport, NY (US);
General Motors Corporation, Detroit, MI (US);
Abstract
Variable valve timing (VVT) mechanisms are disclosed which are relatively compact and are applicable for operating individual or multiple valves. In an exemplary embodiment, dual engine valves are driven by an oscillatable rocker cam that is actuated by a linkage driven by a rotary cam. The linkage is pivoted on a control member that is in turn pivotable about the axis of the rotary cam and angularly adjustable to vary the orientation of the rocker cam and thereby vary the valve lift and timing. The rotary cam is carried on a camshaft and the oscillatable rocker cam is pivoted on the rotational axis of the rotary cam. A control shaft connects with the control member through an angled slider and slot connection that provides a variable angular ratio for improved charge control at low valve lifts. A worm gear actuator may be applied to drive the control shaft. The tooth angles is selected to prevent back driving of the worm drive motor by varying cam torques on the control member so that a smaller drive motor may be used. Other alternative arrangements are disclosed.