Abstract: A presently-preferred embodiment of a quick-release coupler comprises a housing having a first interior surface defining a center cavity and a second interior surface defining a through hole intersecting the center cavity. The coupler also comprises a locking member at least partially disposed in the center cavity and having a first and an opposing second inwardly facing surface partially defining a central passage in the locking member, and a projection extending partially along a length of the first surface. The locking member is movable between a first position wherein the central passage is adapted to removably receive an end portion of a torque-transmitting shaft, and a second position wherein the projection is adapted to engage a recessed portion of the torque-transmitting shaft and thereby inhibit removal of the end portion from the central passage.