Patent ID: 8281872

Claim:
A drill hammer ( 10 ), comprising: a housing ( 12 ); a motor ( 16 ); a gear ( 26 ) having an intermediate shaft ( 28 ), a driving gear wheel ( 30 ), a toothed slaving shaft ( 32 ), a first shifting hub ( 34 ), a second shifting hub ( 134 ), and a driven gear wheel ( 35 ); a percussion mechanism ( 36 ) having a wobble disk ( 40 ) and a wobble gear wheel ( 38 ); and a driven shaft ( 46 ) having another driving gear wheel ( 48 ) and a drill chuck ( 50 ), wherein the driven gear wheel is freely rotatable without axial displacement on the intermediate shaft, wherein the toothed slaving shaft is supported without axial displacement on the intermediate shaft, and wherein the drill hammer, by a power train from the motor to the drill chuck via a combination of the gear, the percussion mechanism, and the driven shaft, with the first and second shifting hubs, arranged separately at opposing sides of toothed slaving shaft ( 32 ) and, independently shifted at a plurality of predetermined shifting positions with respect to the toothed slaving shaft ( 32 ), has three operation modes including a chiseling mode, a drilling mode, and a hammer-drilling mode, in the chiseling mode the drill chuck being in a purely axial reciprocating motion, in the drilling mode the drill chuck in a purely rotating motion, in the hammer-drilling mode the drill chuck in a combined axial reciprocating and rotating motion.