ALEXANDRIA, Va., July 15 -- United States Patent no. 12,660,973, issued on June 23, was assigned to Shanghai Rushen Robotics Co. Ltd (Shanghai).

"Robot cleaner for climbing and cleaning stairs" was invented by Yun Long (Newark, Calif.), Youdong Wang (Newark, Calif.) and Feng Zhu (Newark, Calif.).

According to the abstract* released by the U.S. Patent & Trademark Office: "Embodiments of the disclosure provide a method for controlling a robot cleaner to climb a stair. The robot cleaner includes a main body, at least one leg, and at least one connector connecting each leg to the main body. The method includes rotating the main body relative to the at least one leg to be substantially vertical to a thread of the stair. The method further incl...