US Patent 7300234 Power transmission with bead drive

A power transmission is provided. The power transmission includes a housing including a continuous channel following a three-dimensional path. A plurality of beads is located within the continuous channel and movable therein. A first sprocket is rotateably connected to the housing and forms a first portion of the continuous channel in movable contact with the plurality of beads. A second sprocket is rotateably connected to the housing and forms a second portion of the continuous channel in movable contact with the plurality of beads, the second sprocket having an axis of rotation angled with respect to an axis of rotation of the first sprocket. A milling tool and a method of removing material from a work piece are also provided.