ALEXANDRIA, Va., Dec. 9 -- United States Patent no. 12,491,404, issued on Dec. 9, was assigned to Xiamen Zhoulong Sporting Goods Co. Ltd. (Xiamen, China).
"Stair stepper" was invented by Yu-Chih Chou (Fujian, China).
According to the abstract* released by the U.S. Patent & Trademark Office: "The present invention relates to a stair stepper, including: a rack provided with two slide rails, each of the slide rails is slidably provided with one pedal component, where the two pedal components form linkage in the form of reverse synchronous movement; and a damping mechanism, including a linear elastic element, where the linear elastic element is straddled between the two slide rails, two ends of the linear elastic element are respectively conn...