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:
Mar. 25, 2008
Filed:
Feb. 04, 2002
Scott A. Leman, Eureka, IL (US);
David Andrew Pierpont, Peoria, IL (US);
Scott A. Leman, Eureka, IL (US);
David Andrew Pierpont, Peoria, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
An engine valve actuator providing Miller cycle benefits and a method of operating an engine valve actuator are disclosed. The valve actuator employs a first force to hold an exhaust valve of the engine open during an exhaust stroke and a second, stronger force to hold the exhaust valve open during a compression stroke. The valve actuator may be operated using pressurized fluid adapted to extend an actuator piston through a cylinder. The first force may be derived by a mechanically driven actuator, while the second force may be derived from a high pressure rail of the engine. A low pressure source of the engine may be used to fill the actuator cylinder, with the high pressure rail only being placed into fluid communication with the cylinder when desired. A control valve may be employed to direct either the low pressure or high pressure fluid to the valve actuator cylinder.