US Patent 8939228 Percussion driver drill

In a clutch mechanism of a percussion driver drill, a plurality of engageable members held in a gear case is configured to be engageable with an end face of a final-stage internal gear, and a coil spring is configured to press the engageable members against the end face of the internal gear. The coil spring is disposed frontwardly of the engageable members between a switch member and an operating member of a vibration mechanism. A coupling member connected with the switch member and the operating member is disposed to pass through a gap between the plurality of engageable members and detour around a rear end of the coil spring.