| 摘要 |
882,500. Boring, milling and facing machines; chucks. GIDDINGS & LEWIS MACHINE TOOL CO., and GIDDINGS & LEWIS-FRASER Ltd. Oct. 15, 1957 [Dec. 24, 1956], No. 32255/57. Class 83 (3). Means for securing a tool 18 in a spindle comprises a drawbolt 25 biased inwardly of the spindle by means 36 and means 31, 32, 34 for limiting the axial movements of the drawbolt. The spindle 10 carries a drive pinion 13 and is journalled in a sleeve 12 advanced by a pinion 15. The tool 18 has a tapered shank 19 and slots 22 to receive keys 23. It is necessary to press the tool nearly home in the socket to engage drawbolt threads 28 with an internal thread in the shank 19. Thus, the keys 23 prevent rotation of the tool at all times when the draw-bolt is engaged. The draw-bolt is rotated by a motor through a solenoid-operated clutch. When the clutch is engaged, a switch is actuated to prevent actuation of the spindle-rotating motor, and a magnetic brake is energized to prevent rotation of the spindle. When the draw-bolt is unscrewed to release the tool, a loosening blow is given to the tool when the shoulder 34 on the bolt hits the limiting shoulder 32. |
