ALEXANDRIA, Va., June 16 -- United States Patent no. 12,303,986, issued on May 20, was assigned to Mitsubishi Materials Corp. (Tokyo).
"Rotating tool with coolant hole" was invented by Akira Sato (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "In a rotating tool with a coolant hole, a coolant hole extending to a front side in the direction of an axis opening to a tip flank face of a drill main body that is rotated around the axis. In a cross section orthogonal to the axis, the coolant hole is provided with a first concavely curved portion located on an inner peripheral side of the drill main body and formed in a concavely curved shape recessed to the inner peripheral side, a second concavely curved por...