US Patent Issued to SHANDONG OLD ROUGHNECK MACHINERY TECHNOLOGY, SHANDONG ZHIWEI MACHINERY on Sept. 1 for "Micro-reinforced concentric twist drill" (Chinese Inventors)

ALEXANDRIA, Va., Sept. 1 -- United States Patent no. 12,722,213, issued on Sept. 1, was assigned to SHANDONG OLD ROUGHNECK MACHINERY TECHNOLOGY Co. LTD (Shandong, China) and SHANDONG ZHIWEI MACHINERY Co. LTD. (Shandong, China).

"Micro-reinforced concentric twist drill" was invented by Shiqing Li (Tai'an city, China), Aiquan Wang (Jinan city, China) and Jianhua Zhang (Jinan city, China).

According to the abstract* released by the U.S. Patent & Trademark Office: "A micro-reinforced concentric twist drill. Concentric drilling and micro-reinforcing technologies are applied to cutting faces of the twist drill, and upright micro-reinforced center drills are symmetrically arranged on spiral cutting surfaces on two sides of an axial central area,...