Patent ID: 8677869

Claim:
A tailstock device comprising a tailstock that is reciprocated by a servomotor via a lead screw mechanism, and a tailstock center attached to the tailstock, the tailstock device supporting a workpiece by pressing the tailstock center against the workpiece, the tailstock device comprising: a normal tailstock thrust setting means for setting, as a torque limit value of the servomotor, a tailstock thrust required for supporting the workpiece; a low tailstock thrust setting means for applying a tailstock thrust lower than the normal tailstock thrust to the tailstock center through manual operation, the low tailstock thrust setting means operating to press a distal end of the tailstock center against the workpiece; a display means for displaying the tailstock thrust of the tailstock center applied to the workpiece; and a disabling means, wherein, when the actual thrust of the tailstock center exceeds a maximum thrust value in a state where a screen of the display means has been switched to a low thrust mode, the disabling means disables the manual operation, wherein, when the actual thrust of the tailstock center is less than or equal to the maximum thrust value and outside a permissible range, the disabling means does not disables the manual operation, and wherein, when the actual thrust of the tailstock center is less than the maximum thrust value and within the permissible range, the disabling means disables the manual operation.