摘要 |
A spindle driver for a machine tool is disclosed which is adapted to move the spindle and a tool driven thereby in a helical path with variable pitch and with an orbital radius which may be varied. A quill is mounted on a support member and driven by a variable pitch drive mechanism in the form of a differential lead screw to provide a selectable ratio of axial motion to rotative motion of the quill. A spindle carrier is rotatably mounted on the quill for rotation about an eccentric axis offset from the quill axis. A spindle motor and a spindle driven thereby is mounted on a carrier with the spindle axis offset from the eccentric rotation axis. The orbital radius for the spindle is adjustable by rotation of the spindle carrier about the eccentric rotation axis to adjust the offset of the spindle axis. |