Patent ID: 8028760
Filing Date: 2011-10-04
Classification: B25D

Abstract:
1. A hammer drill comprising: a tool holder being supported rotatably at a front part in a housing and capable of mounting a bit on a front end thereof; an impact mechanism configured to impact the bit provided at a rear part of the tool holder; a motor provided at a rear part in the housing; an intermediate spindle configured to receive rotation from an output spindle of the motor and being supported in parallel with the tool holder; a rotation transmitting member being rotatably provided at a front part of the intermediate spindle as a separated body, and configured to transmit a rotation of the intermediate spindle to a tool holder side; an impact transmitting member being rotatably provided at a rear part of the intermediate spindle as a separated body, and configured to convert the rotation of the intermediate spindle to a fore and aft movement so as to transmit the movement to the impact mechanism; a clutch member being provided between the rotation transmitting member and the impact transmitting member, being integrally rotatable with the intermediate spindle, being slidable in the fore and aft direction, and being capable of engaging with and releasing from the rotation transmitting member or the impact transmitting member or both, depending on a sliding position; a mode switching member being provided at the housing and capable of rotationally operating; an engaging pin being provided at an eccentric position of the mode switching member, capable of advancing and retreating with a predetermined stroke toward an outer periphery of the clutch member, and being biased to an engaging position with the outer periphery of clutch member by a biasing member, wherein: an operation mode of the hammer drill is configured to be selected from: a lock member configured to engage with the rotation transmitting member and capable of locking the rotation of the rotation transmitting member and being provided slidably between an engaging position with the rotation transmitting member and a non-engaging position with the rotation transmitting member in the housing; and a restriction part being provided on an outer peripheral side of the engaging pin in the mode switching member, wherein: