US Patent 7587791 Tool

A tool includes a handle, a controller and a bit. The handle includes a socket defining an axial non-circular space and a radial space in communication with the axial space. The controller includes a space defined therein and a ridge formed on the wall of the space thereof. The controller is movable in the radial space of socket between a locking position and a releasing position. The bit includes a working tip and a shank defining at least one recess for receiving the ridge when the shank is inserted into the space of the controller through the axial space of the socket, thus locking the bit to the handle.