Patent ID: 8555998

Claim:
A hammer-drill comprising: a housing having a motor including an output member; a rotary-reciprocatory output spindle journaled in the housing; a transmission disposed in the housing and driven by the output member, the transmission being operable to rotatably drive the output spindle via a first low speed gear or a second high speed gear; a hammer mechanism operable when enabled to deliver vibratory impacts to the output spindle; a manually operable mode selection device mounted on the housing for selecting one of a plurality of operation modes comprising: (i) a low speed mode wherein the output spindle is rotatably driven via said first low speed gear, (ii) a high speed mode wherein the output spindle is rotatably driven via said second high speed gear, and (iii) a hammer-drill mode wherein the hammer mechanism is enabled; and a transmission shifting mechanism coupled between the transmission and the mode selection device and movable between a first position and a second position for shifting the transmission between said first low speed mode and said second high speed mode, respectively, said transmission shifting mechanism including a locking mechanism for maintaining the transmission in said second high speed mode; wherein said hammer mechanism can only be enabled when said output spindle is rotatably driven via said second high speed gear.