ALEXANDRIA, Va., March 19 -- United States Patent no. 12,251,765, issued on March 18, was assigned to SUMITOMO ELECTRIC HARDMETAL CORP. (Itami, Japan).
"Drill" was invented by Youichi Takahashi (Itami, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A ridgeline between the thinning face and the flank face includes a first thinning portion contiguous to the outer cutting edge, and a second thinning portion contiguous to the first thinning portion. When viewed in a direction along the central axis, the first thinning portion is linear and the second thinning portion is curved. When viewed in the direction along the central axis, the first thinning portion, and a boundary between the first thinning portion...