US Patent 9918428 Rotating assembly for grass trimmer

A rotating assembly for a grass trimmer includes a cutting element, a cutting head for mounting the cutting element and driving the cutting element to rotate about a rotating axis and a cover mounted on the cutting head. The cutting head includes a cutting head body and fan blades for generating an air flow when the cutting head being rotated, which are disposed on a top of the cutting head. The cover includes a cover body and protecting ribs for preventing the fan blades from wearing.