ALEXANDRIA, Va., June 10 -- United States Patent no. 12,292,118, issued on May 6, was assigned to TPR Co. Ltd. (Tokyo).
"Piston ring" was invented by Yushi Abe (Tokyo), Naoki Umeda (Tokyo), Masayuki Ohira (Tokyo) and Akira Hikone (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "An outer circumferential surface of a piston ring has a cut surface forming a notched portion between an outer circumferential end surface and a lower surface, the cut surface including a first surface between the outer circumferential end surface and a bottom portion, and a second surface between the bottom portion and the lower surface. The second surface is inclined away from a central axis of the piston ring as it extends tow...