Method and apparatus for determining the working range of a

Abstract

The present invention relates to a method and apparatus for determining a working range of a double-acting clamping cylinder for actuation of operating devices, such as supporting, centering or chucking devices, respectively on machine tools, particularly replaceable chucks on lathes, giving consideration to a post-tightening distance and controlling of the drive for effecting of the machining of the workpiece. In order to avoid a replacement of control cams or adjustment of limit switches of the prior art, the total path of the clamping cylinder is monitored by a length-measuring instrument which gives off electric pulses to a control device which determines the total stroke of the corresponding supporting, centering or clamping device and stores in the control device the end positions thereof lying within the total path of the clamping cylinder within and, with due consideration to the post-tightening stroke associated with the corresponding operating device, determines the working range of the clamping cylinder for the respective operating device outside of which working range the drive for effecting the machining of the workpiece is blocked by the control device.