| 摘要 |
PURPOSE:To produce a short spindle and elongate the life of holding claws by pivotably opening and closing a plurality of holding claws pivoted about pins with a draw bar disposed movably forward and backward in a rotary spindle, and enabling a tool to be removably attached. CONSTITUTION:A holding cylinder 30 having holding claws 11 pivoted about supporting pins 12 is fixedly secured to an end of a draw bar 7 disposed concentrically in a rotary spindle. The holding claws 11 are urged normally to open between the draw bar 7 and a sleeve 15 and provided at the supporting pin 12 side base end with a projection 13 which engages a concave annular groove 14 provided in the draw bar 7. The holding claws 11 is slidably inserted into the sleeve 15 secured fixedly to the inner surface of the spindle 3. The draw bar 7 is normally urged to move rearward and moved forward by the operation of a cylinder against such energization. Then, the holding claws 11 are drawn out of the sleeve 15 while the ends of the claws 11 can be opened. |
