| 摘要 |
PURPOSE:To reduce the effect of oscillation due to a feed motor and to improve the precision for threading by a method wherein after something of positive tap feed is conducted threading is conducted by the propelling force of a tap due to the rotation of a main spindle. CONSTITUTION:The tap 13 is fixed to the main spindle 3 through an arbor 4, a bearing 5, a washer 6, a spring, a spline 8, a notch 9, a spring 10, a claw 11, a holder 12, etc. so that the tap 13 can move in the direction of the main spindle 3. And, when the tap 13 in threading exceeds a decided amount of move, the engagement with the spline 8 is released and only a little feed is conducted by the feed motor so that threading can be conducted by the propelling force of the tap 13 due to the rotation of the main spindle 3. When reversed, the main spindle 3 is provided so that its rotation can be transmitted to the tap 13 by the engagement of the notch 9 with the claw 11. |
