ALEXANDRIA, Va., July 28 -- United States Patent no. 12,692,938, issued on July 28.
"Piston ring set" was invented by Takeshi Yamada (Niigata, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A piston ring set according to one aspect includes a top ring and an oil ring, and is inserted into a cylinder bore of an internal combustion engine, the top ring has an annular main body portion including an inner peripheral surface, an outer peripheral surface, one side surface and the other side surface substantially perpendicular to the inner peripheral surface, and a first joint end portion and a second joint end portion that face each other to form a joint portion, the oil ring has a pair of rails facing each ...