To prevent the entanglement of pipes connected to a plurality of pressing cylinders by providing a control means for driving a driving means so as to bring a connecting part into contact with a connected part and feeding actuating pressure to the pressing cylinders.

When coming of the connected part of a pallet 2 to a specified position of first, second, third and fourth positions A, B, C and D is detected by a limit switch 32, a detecting signal for this is outputted to a control panel 31. A command is issued from the control panel 31 to a work cylinder 30 and, by the actuation of this work cylinder 30, connecting parts in the first, second, third and fourth positions A, B, C and D are contacted with connected parts and first and second passages are communicated with each other. Then, work pressure is fed from a work pressure supply source through the connecting and connected parts to a pressing cylinder 4.