Patent ID: RE40643

Claim:
A rotary hammer, which comprises: an intermediate shaft ( 24 ) which is rotatably driven by a motor of the rotary hammer when power is supplied to the motor; a spindle ( 18 ) which can be driven in rotation about its axis by the intermediate shaft 24 through a spindle drive arrangement ( 62 , 64 ); a tool holder ( 16 ) arranged for rotation with the spindle ( 18 ) for releasably holding a bit or a tool such that the bit or tool can reciprocate; a pneumatic hammering arrangement ( 20 , 21 , 22 ) located within the spindle ( 18 ) which can repeatedly impact the bit or tool held within the tool holder ( 16 ); said pneumatic hammering arrangement comprising a piston ( 20 ) which can be reciprocally driven by a hammer drive arrangement ( 34 , 36 , 38 , 39 , 40 , 42 ) which can translate rotary drive from the intermediate shaft ( 24 ) to a reciprocating drive to the piston ( 20 ); and a mode change mechanism for changing the operation of the rotary hammer to operate in any of three modes, a rotary drive only mode, a hammer only mode or a rotary hammer mode; said mode change mechanism comprising: a single actuator ( 8 ) switchable by a user of the rotary hammer amongst the three modes of operation; a spindle driving member ( 56 ) rotatable on the intermediate shaft ( 24 ) for driving the spindle drive arrangement ( 62 , 64 ); a hammer driving sleeve ( 34 ) rotatable on the intermediate shaft ( 24 ) for driving the hammer drive arrangement ( 34 , 36 , 38 , 39 , 40 , 42 ); and a mode change sleeve ( 52 ) which is permanently driven by the intermediate shaft ( 24 ) and shiftable along the intermediate shaft ( 24 ) to change the operation of the rotary hammer to operate in any of the three modes ; where, upon the switching of the actuator ( 8 ) by a user, shifts the mode change sleeve ( 52 ) along the intermediate shaft ( 24 ) amongst the three modes positions, such that in a first rotary drive only position the mode change sleeve ( 52 ) transmits rotary drive to the spindle driving member ( 56 ) to transmit rotary drive to the spindle drive arrangement ( 62 , 64 ), in a second hammer only position the mode change sleeve ( 52 ) transmits rotary drive to the hammer driving sleeve ( 34 ) to transmit rotary drive to the hammer drive arrangement ( 34 , 36 , 38 , 39 , 40 , 42 ), and in a third rotary hammer position the mode change sleeve ( 52 ) transmits rotary drive to the spindle driving member ( 56 ) and to the hammer driving sleeve ( 34 ) to transmit rotary drive to the spindle drive arrangement ( 62 , 64 ) and to the hammer drive arrangement ( 34 , 36 , 38 , 39 , 40 , 42 ).