ALEXANDRIA, Va., Sept. 10 -- United States Patent no. 12,413,881, issued on Sept. 9, was assigned to AAC Microtech (Changzhou) Co. Ltd. (Changzhou, China).
"Front cover structure and sounder" was invented by Qibo Li (Changzhou, China), Siyuan Ni (Changzhou, China), Jingwei Yu (Changzhou, China) and Zhongfeng Gao (Changzhou, China).
According to the abstract* released by the U.S. Patent & Trademark Office: "A sounder includes a frame with an accommodating space, a magnetic circuit unit fixed in the accommodating space of the frame, a vibration unit fixed to the frame and spaced apart from the magnetic circuit unit and driven by the magnetic circuit unit to vibrate, and a front cover structure covering the frame and the vibration unit and m...