US Patent 7073606 Manual machine tool

The invention is based on a power tool comprising toolholder (12, 102) driveable in at least rotary fashion via a drive motor and via a driven shaft (10, 98, 100), which comprises a workholding fixture (14) for attaching tools (16, 104) actuatable in the direction of rotation of the driven shaft (10, 98, 100), and comprising a locking device (18, 86, 90), via which the driven shaft (10, 98, 100) is coupleable in torsion-resistant fashion for locking and releasing the workholding fixture (14) to and from a housing part (20, 106), and which opens automatically when torque is transferred from the drive motor to the toolholder (12, 102), and which locks automatically when torque is transferred from the toolholder (12, 102) to the drive motor.