ALEXANDRIA, Va., Feb. 3 -- United States Patent no. 12,539,939, issued on Feb. 3, was assigned to SUN RACE STURMEY-ARCHER INC. (Taoyuan, Taiwan).
"Transmission device for bicycle" was invented by Shou-Chiang Chien (Taoyuan, Taiwan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A transmission device for bicycle comprises a sprockets cluster, a second sprocket and a lock ring. The sprockets cluster has plural sprockets, one of the sprockets is a first sprocket, which has a first sprocket teeth, a protrusion of first sprocket and plural splines of first sprocket. The second sprocket has a second sprocket teeth, a protrusion of second sprocket, plural splines on second sprocket, and an opening of second sprocket...