METHOD OF AND APPARATUS FOR MODIFYING THE CURVATURE OF A SPLIT PISTON RING BY LOCALIZED HEATING

摘要

A method and apparatus for forming piston rings are disclosed. A split piston ring made by conventional processes is locally heated along its inside surface for a short distance either side of the split. This causes a short length of the ring on either side of the split to curl into a slight inward protrosion due to internal yielding of the restrained heated area and subsequent tensioning during cooling. The inwardly curved configuration prevents catching of the ring's ends on gas ports of ported cylinder engines.