ALEXANDRIA, Va., June 16 -- United States Patent no. 12,303,734, issued on May 20, was assigned to QINGDAO KINGDOM HEALTH INDUSTRY Co. LTD. (Shandong, China).
"Adjustable dumbbell" was invented by Zhixiong Wang (Shandong, China).
According to the abstract* released by the U.S. Patent & Trademark Office: "An adjustable dumbbell includes a dumbbell bar, linear adjusting mechanisms and counterweight mechanisms disposed at both ends of the dumbbell bar. The dumbbell bar includes a sleeve and two telescopic mandrels disposed in the sleeve and in sliding fit with each other, the counterweight mechanisms are coaxially disposed at both ends of the dumbbell bar, and configured to provide the overall weight of the adjustable dumbbell. Each linear a...