An actuating arrangement for a tool clamping device (1) has a clamping bar (3) which is axially displaceable in a clamping direction in a machine tool spindle (2) under the effect of a spring arrangement (11), and a wedge transmission assembly (9) which is operable between the spindle and the clamping bar, with freely movable balls which bear respectively against three cone surfaces of which the first is provided on a clamping sleeve (10) which is axially displaceable in the clamping direction on the clamping bar under the force of the spring arrangement (11), the second is provided on a clamping ring (12) connected to the clamping bar (3) and the third is provided on a support ring (13) which is arrangd stationarily with respect to the spindle. Provided on the support ring is a fourth cone surface (18) which is inclined relative to the axis of the clamping bar in opposite relationship to the third cone surface. A piston-cylinder unit (7, 8) is releasably connected to a release ring (20) provided in the region of the balls (14), by way of a locking means which acts in dependence on travel movement.