ALEXANDRIA, Va., March 17 -- United States Patent no. 12,576,452, issued on March 17, was assigned to Mitsubishi Materials Corp. (Tokyo).
"Drill" was invented by Akira Sato (Tokyo) and Katsuhiro Nagasawa (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A chip discharging flute is formed in a tip outer peripheral portion of a drill body rotated around an axis in a drill rotation direction. A cutting edge is formed in an intersection ridgeline portion between a wall surface of the chip discharging flute facing the drill rotation direction and a tip flank. The cutting edge includes a main cutting edge portion extending from an inner peripheral side toward an outer peripheral side of the drill body, and a c...