A hammer drill has an elastic member without using a coil spring or the
like on an intermediate spindle to compact a housing and decrease cost.
The elastic member that elastically engages a clutch with a second gear
and/or a boss sleeve includes first to third guide spindles, first and
second interlock plates, and a coil spring. The guide spindles are
provided in parallel with an intermediate spindle. The first and second
interlock plates are provided at the first to third guide spindles and
slidable integrally with the clutch by engaging with the clutch. The coil
spring energizes the first and second interlock plates along the first to
third guide spindles.