US Patent 7121167 Flat head reversible power ratchets

A flat headed, reversible power ratchet of relatively small size which uses integral bosses and apertures in its housing to locate and control the movement of its yoke and driving gears on bosses integral to the housing with the driving gear mounted in a bore within the yoke, which has its pawls and pawl controls within the yoke adjacent the gear, and by utilizing a pair of linkages which pivot about the yoke and about the housing in overlapping arcs to stabilize the position of the directional controls during operations.