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:
Dec. 07, 1999
Filed:
Mar. 03, 1998
Juergen Kling, Wiernsheim, DE;
Ing. h.c.F. Porsche AG, Weissach, DE;
Abstract
In order to prevent penetration of lubricant into the combustion chamber, a piston for an internal combustion engine has a labyrinthine pressure equalizing passage between the combustion chamber and the crankcase. For this purpose, the piston ring closest to the combustion chamber is guided with relatively large axial play in the matching annular groove. The piston rings located farther from the combustion chamber are each provided with recesses that connect the annular chamber between the adjacent piston rings with the bottom of the respective annular groove. A bore is also provided in the annular groove that is farthest from the combustion chamber, the bore connecting the bottom of the annular groove with an interior chamber defined in the piston. In this way, the pressure can equalize between the combustion chamber and the crankcase.