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:
Sep. 22, 1998
Filed:
Dec. 22, 1995
E Grant Swick, Bartlett, IL (US);
Other;
Abstract
A method for making non-circular piston rings which will precisely sealably conform to the cylinder wall of an internal combustion engine. In accordance with the method a metal strip of special cross-sectional configuration is coiled about a specially configured mandrel which is non-circular in cross section. Preferably the coiling mandrel is provided with a circumferentially interrupted thread form that has a zero helix angle along most of its circumference. During the coiling operation, using this type of mandrel, the metal strip is preformed at specific locations along its length into an angled configuration to form a coil body having a plurality of coils that have a zero helix angle along most of their circumference and a relatively steep helix angle for a short distance. After the coil is formed, the helix angle portions are cut therefrom to provide a plurality of generally planer, interrupted rings.