Patent ID: 7273112

Claim:
An electric power tool, comprising a drive mechanism switchable back and forth among a drilling, a percussion drilling, and a chiseling mode of operation; a drive shaft performing a rotary motion; a percussion mechanism provided with a drive bearing; a serrated sleeve supported axially displaceably in said drive bearing of said percussion mechanism and transmitting a rotary motion of said drive shaft to said drive bearing of said percussion mechanism when the drive bearing is in an axial position corresponding to the chiseling of percussion drilling modes of operation; and an axially displaceable serrated shaft supported in said drive bearing, so that said serrated sleeve transmits to said serrated shaft the rotary motion of said drive shaft when said serrated shaft is in axial position corresponding to the drilling or percussion drilling modes of operation, wherein the serrated shaft is driven by rotary motion of the serrated sleeve via slaving teeth, and wherein the serrated shaft is axially displaceable with respect to the serrated sleeve so that the slaving teeth are disengaged, thereby providing said chiseling mode of operation.