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. 10, 2012
Filed:
Dec. 04, 2008
Jean-pierre Pirault, Shoreham-by-Sea, GB;
Riccardo Meldolesi, Hove, GB;
Christopher Chadwell, San Antonio, TX (US);
Jean-Pierre Pirault, Shoreham-by-Sea, GB;
Riccardo Meldolesi, Hove, GB;
Christopher Chadwell, San Antonio, TX (US);
Southwest Research Institute, San Antonio, TX (US);
Abstract
A hydraulic variable compression ratio (VCR) piston for use in an internal combustion engine. The piston is a two-part piston, in which a gudgeon pin carrier slides within an outer sleeve. A variable volume upper chamber is formed between the top of the gudgeon pin carrier and the end of the outer sleeve. When the upper chamber fills with oil, its volume increases, and the overall piston geometry is longer. This reduces the piston clearance in the cylinder and increases cylinder pressure. At a given maximum cylinder pressure or at a given rate of increase of cylinder pressure, oil from the upper chamber is relieved by using a rate-sensitive pressure relief valve.