US Patent 7275981 Symmetrical wall sander

A disc-shaped sanding pad has a round perimeter. Centrally located in the pad is a socket. A ball, coupled to the end of a handle, is inserted into the socket, permitting the sanding pad to both pivot and rotate freely about the handle. A second single axis pivot is also provided in the preferred embodiment between the handle and sanding pad, which permits the handle to traverse an area greater than a hemisphere about the sanding pad socket.