an auxiliary block 30 fastened on the plate 22 thus the pins 23 can be tensioned to an adjustable degree by moving the piston 26 and the plate 29 fixed thereto by push rods 28 to the right in fig2 to bear against the block 30 and apply forces tending to move the plate 22 to the right the plate 22 is clamped as a force transfer element between the stop nuts 20 and the stops 31 on the pins 23 fig3 a shows in a partial sectional view an enlarged representation of the stationary plate 22 between a stop nut 20 and a stop 31 on a pin 23 in accordance with fig2 it can be seen that the pin 23 is passed through a bore 32 in the plate 22 on the side facing the stop 31 a threaded ring 34 is screwed into a part of the bore 32 provided with a thread 33 the threaded ring 34 engages via dogs 35 a pre seated divided ring 36 by means of which it can be connected in an adjustable and force locking manner with the stop 31 on the pin 23 the divided ring 36 has cutouts 37 for receiving an adjustment tool it is assumed in fig3 a that the screw connection between the stop nuts 20 and the pins 23 has.