| 摘要 |
<p>A method and apparatus for machining hourglass screw threads on an enveloping-type worm screw by engaging at least one angularly positioned cutter (26, 26') with a screw blank (48) having an hourglass shape. The screw blank (48) is rotated about its central longitudinal axis (50) at the same time that each angularly positioned cutter (26, 26') is pivoted through the screw blank (48) at a rate which is less than the rate of rotation of the screw blank (48).</p> |
