ALEXANDRIA, Va., Oct. 21 -- United States Patent no. 12,442,253, issued on Oct. 14, was assigned to METAL TOOL INC (Aichi, Japan).
"Twin bit" was invented by Takemi Ishizuka (Aichi, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "According to one embodiment, a twin bit includes a main bit and an auxiliary bit. A carbide tip having a mountain shape protruding in an excavation direction is arranged at least on a top portion and a bottom portion that are located on a front end of a base portion of each of the main bit and the auxiliary bit. An apex portion of the mountain shape of the carbide tip of the auxiliary bit is located further behind an apex portion of the mountain shape of the carbide tip of the ...