The invention relates to a drive device for clamping and releasing a tool in the tool holding fixture of a tool holder. The drive device according to the invention prevents incorrect operation; said drive device can be operated manually or by a handling robot and can be actively locked to the tool holder.

A changer device for inserting a clamping head into and/or removing the clamping head from the clamping chuck, wherein the clamping head has a plurality of clamping jaws mutually displaceable in a radial direction and which can be mutually subjected to force by the changer device toward or away from one another in the radial direction. The changer device has a base and a plurality of adjusting elements which are movably attached to the base and which in each case have at least one engagement portion for the application of force onto the clamping jaws. The changer device has a drive member which is rotatably movable about a central axis relative to the base. The drive member is coupled by a gear mechanism to the adjusting elements such that by a rotational movement of the drive member the adjusting elements can be jointly moved toward or away from one another.