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. 04, 2003
Filed:
Feb. 06, 2002
James B. Hicks, Shelby Township, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An engine has switching valve actuators with positive valve lash for actuating or deactivating valves of deactivation cylinders and conventional valve actuators with negligible valve lash for actuating valves of conventional cylinders. Cams for the deactivation cylinders have increased opening and closing ramps relative to cams of the conventional cylinders. This can lead to poor combustion quality at idle and light loads and result in perceived engine roughness by an operator. To compensate for this, timing of exhaust cams of the deactivation cylinders is advanced relative to those of the conventional cylinders to reduce valve overlap of the deactivation cylinders to sufficiently near that of the conventional cylinders to provide stable combustion at idle in both conventional and deactivation cylinders with nearly equivalent power operation of all the cylinders.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile