To compress the springs 162, the first end 176 of the member 172 is moved in a direction indicated by arrow 184 along the rotational axis 36 of the collet 38 by injecting a fluid, such as air or oil, through a valve 136 to compress a piston and cylinder arrangement, such as a hydraulic cylinder or preferably a pneumatic cylinder 186, to apply pressure to the housing 188 connected to the first end