ALEXANDRIA, Va., Oct. 28 -- United States Patent no. 12,447,589, issued on Oct. 21.
"Engagement structure of ratchet wrench" was invented by Chen Tzu Chun (Taichung, Taiwan).
According to the abstract* released by the U.S. Patent & Trademark Office: "An engagement structure of a ratchet wrench, the ratchet wrench contains: a body which including a drive head, a ratchet portion, and the engagement structure. The engagement structure includes a through orifice, a first defining notch, a second defining notch, a receiving notch, and a spring. An abutting member includes a first arcuate cutout, a coupling column, a locking orifice, and a first limitation protrusion. A retainer is mounted on the through orifice and includes a second arcuate cu...