A machine produces an adhesively bonded book block. The machine has a clamp chain equipped with spaced apart binder clamps, which are connected to a clamp opening system. The clamp opening system has a movable internal aid for a binder clamp and an external aid, which are operably connected together. The aids open clamping jaws of the binder clamp. At a loading location for the book block, the external aid is operated by a drive to execute pressing operation on the movable internal aid. The moveable internal aid achieves an opening of the clamping jaws depending on a thickness of the book block. A recoil force is established with the drive-related pressing operation, which is converted as a pressing force onto the book block in a running cycle.