Tool head and method of operating a tool head

A tool head for a machine tool, comprising:

• a first spindle unit with at least one first spindle bearing and a first spindle shaft which is mounted in the first spindle bearing so as to be rotatable about a tool spindle axis, the first spindle bearing being configured to absorb both radial and axial forces;
• and
• a second spindle unit with at least one second spindle bearing and a second spindle shaft which is mounted in the second spindle bearing so as to be rotatable about the tool spindle axis, the second spindle bearing being configured to absorb both radial and axial forces,
• wherein the first spindle unit and the second spindle unit are arranged coaxially with respect to each other in such a way that a tool is receivable axially between the first spindle shaft and the second spindle shaft,
• wherein the tool head comprises a controlled clamping device for controllably connecting the first spindle bearing and the second spindle bearing to one another, and
• in that a control device is associated with the tool head, the control device being configured to activate the clamping device during a machining operation and to deactivate it during machining pauses.