US Patent 7171873 Tensionless power ratchet wrench assembly

A power ratchet wrench assembly having a tensionless head wherein operation of the ratchet mechanism does not require a tensioning means for applying a frictional force against the ratchet mechanism to inhibit rotational movement of the ratchet mechanism. In one embodiment, the invention provides a first gear, a second gear, and a ratchet mechanism having a drive body; wherein the drive body is alternately: coupled to the first gear and ratcheting with the second gear, and coupled to the second gear and ratcheting with the first gear.