| 摘要 |
An improved machine tool for operating on bar stock includes a chuck for holding the bar stock with a leading end portion extending toward a work station and a trailing end portion extending in a direction away from the work station. Bar stock is fed from the chuck to the work station by a gripper assembly which pulls the bar stock out of the chuck. As the bar stock is fed to the work station, a signal generator provides signals representative of changes in the length of the trailing end portion of bar stock. To insure that sufficient bar stock is left in the chuck for proper holding during operation of the machine in response to signals from the signal generator indicating that the trailing end portion of the bar stock is shorter than a predetermined length. The numerical control system is activated by a bar end detector when the trailing end surface of the bar stock is in a predetermined location and a known length of bar stock is available for feeding to the work station.
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