ALEXANDRIA, Va., June 5 -- United States Patent no. 12,276,197, issued on April 15, was assigned to KOMATSU LTD. (Tokyo).
"Tunnel excavation device" was invented by Naoki Sekiyama (Tokyo), Hiroshi Asano (Tokyo), Taku Arakawa (Tokyo), Shinichi Terada (Tokyo) and Eiichi Morioka (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A tunnel excavation device includes a front body portion configured to support a cutter head and a rear body portion. The rear body portion includes a gripper carrier and a gripper portion. The gripper carrier is disposed in a rear of the front body portion. The gripper portion is provided on the gripper carrier. The gripper portion includes a groove portion and a wheel portion. The ...