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A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to gener

A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to generate a reciprocating motion on an output spindle or shaft. A spindle locking mechanism is included which causes an intermediate gear to be disengageable with respect to the output shaft, while still permitting the impact mechanism to be engaged. Such an arrangement allows the hammer drill to operate in a hammer-only or chipping mode.

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A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to gener

A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to generate a reciprocating motion on an output spindle or shaft. A spindle locking mechanism is included which causes an intermediate gear to be disengageable with respect to the output shaft, while still permitting the impact mechanism to be engaged. Such an arrangement allows the hammer drill to operate in a hammer-only or chipping mode. first and second cam mechanisms are configured with respect to each other and the first and second planetary gear sets to generate reciprocating motion of the outer gear in the second planetary gear set in response to rotation of the armature shaft which in turn transmits the reciprocating motion to the output gear thereby axially reciprocating the output shaft. 4. The hammer drill of claim 3 wherein the pinion gear of the second planetary gear set forms an axially displaceable second gear such that rotation of the output shaft can be prevented by selectively moving the axially displaceable pinion gear out of engagement with the outer gear of the second planetary gear set, thereby providing a chipping mode by allowing the intermediate gear reduction arrangement to transmit the reciprocating motion to the output gear irrespective of whether the outer gear of the second planetary gear set and the output gear are in rotational engagement.