US2478929A - Machine tool - Google Patents
US2478929A US524167A US52416744A US2478929A US 2478929 A US2478929 A US 2478929A US 524167 A US524167 A US 524167A US 52416744 A US52416744 A US 52416744A US 2478929 A US2478929 A US 2478929A Authority US United States Prior art keywords spindle tracer gear headstock clutch Prior art date Legal status (The …