Patent ID: 7647985

Claim:
A hammer drill comprising: a tool bit having a longitudinal axis; a first driving mechanism part that linearly drives the tool bit along the longitudinal axis; a first clutch mechanism disposed in the first driving mechanism part and switchable between a power transmission state of transmitting a driving force and a power transmission interrupted state of interrupting the transmission of the driving force; a second driving mechanism part that rotationally drives the tool bit about the longitudinal axis; a second clutch mechanism disposed in the second driving mechanism part and switchable between a power transmission state of transmitting a driving force and a power transmission interrupted state of interrupting the transmission of the driving force; and a driving mode switching mechanism that switches the driving mode of the tool bit among a hammer mode in which the tool bit is caused to perform striking movement along the longitudinal axis, a drill mode in which the tool bit is caused to perform rotation about the longitudinal axis and a hammer drill mode in which the tool bit is caused to perform striking movement and rotation, wherein the driving mode switching mechanism includes: an operating part having a circumference, the operating part being turnable on a predetermined rotation axis by a user; a first switching member, activated by turning the operating part, switches the state of the first clutch mechanism; and a second switching member, activated by turning the operating part, switches the state of the second clutch mechanism; the operating part can be turned to at least three rotating positions around the circumference; a first of the three rotating positions switches the first clutch mechanism to the power transmission state by activating the first switching member and switches the second clutch mechanism to the power transmission interrupted state by activating the second switching member, whereby the hammer mode is selected as the driving mode of the tool bit; a second of the three rotating positions switches the first clutch mechanism to the power transmission interrupted state by activating the first switching member and switches the second clutch mechanism to the power transmission state by activating the second switching member, whereby the drill mode is selected as the driving mode of the tool bit; and a third of the three rotating positions switches the first clutch mechanism to the power transmission state by activating the first switching member and switches the second clutch mechanism to the power transmission state by activating the second switching member, whereby the hammer drill mode is selected as the driving mode of the tool bit; and the operating part can be turned 360° on the rotation axis in opposite directions.