摘要 |
A fluid-actuated type hollow power chuck has a hollow cylindrical chuck body with a forward part of larger outer diameter and a rearward part of small outer diameter. A cylinder body of a hollow cylindrical shape is secured to and around to the outer surface of the rearward part of the chuck body so as to form an annular cylinder chamber. A piston slidable in the cylinder chamber to operate the jaws has a piston sleeve extending rearward therefrom between the chuck body and the cylinder body, the displacements of the piston sleeve being detected at points rearward of the cylinder body by proximity switches installed in a ring disposed to the rear of the cylinder body, whereby displacements of the jaws are indirectly indicated by the switches. |