Operation unit activated by fluid action has contraction tube between head pieces and that can be radially expanded and exert axial tension force and has force overload prevention

摘要

The operation unit (1) has a contraction tube (4) between two head pieces (2,3). The contraction tube can be radially expanded by fluid acting on its interior (13) and exerts an axial tension force on the head pieces. The contraction tube is fixed at a holder unit (6) of each head piece. Each head piece has external force tapping devices (17,18). A force overload prevention (23) is connected in the force flow connection between the holder part and the force tapping device of at least one head piece to allow relative movement between the force tapping device and the holder unit when a given maximum force is exceeded. Control devices (26) enable a controlled fluid exit from the tube interior when the force overload prevention is activated.