Patent ID: 7011165

Claim:
An electric hand tool apparatus for driving a drilling tool effecting at least partially a rotational movement and comprising a housing ( 2 ), an electric motor ( 4 ) within said housing, free of a collector and slip ring for producing a torque, motor control electronics ( 3 ) including a microcontroller within said housing ( 2 ) in operational engagement with said electric motor ( 4 ) and arranged to control the rpm of said electric motor and to actively rapidly brake said electric motor, a force transfer path from said motor ( 4 ) to a transmission ( 6 ), and a strictly mechanical rpm-dependent clutch ( 5 ) in the force transfer path between said electric motor ( 4 ) and said transmission ( 6 ) for transmitting torque from said electric motor ( 4 ) to said transmission ( 6 ), and a sensor ( 7 ) evaluated by said microcontroller is connected within and to said housing ( 2 ) for determining a future excessively high twisting of said housing for actively braking said electric motor, whereby a torque transfer from said electric motor to said transmission is interrupted when rpm of said electric motor, which is being braked, is less than rpm of said clutch.