ALEXANDRIA, Va., March 26 -- United States Patent no. 12,258,864, issued on March 25, was assigned to KOMATSU LTD. (Tokyo).
"Tunnel excavation device" was invented by Masahiro Suwano (Tokyo), Naoki Sekiyama (Tokyo), Hiroshi Asano (Tokyo) and Taku Arakawa (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A tunnel excavation device includes a main body a frame and a workbench. The main body includes a front body section and a rear body section. The front body section includes a cutter head provided with a plurality of disk cutters. The rear body section is disposed behind the front body section and includes a gripper section for obtaining a reaction force when excavating. The frame is disposed continuously...