| 摘要 |
A lathe comprising a first headstock (12) having a first rotatable spindle (17) carrying a respective workpiece gripping device (17a) a second headstock (14) having a second rotatable spindle (18) carrying a respective workpiece gripping device (18a) the headstock (14) being presented towards the headstock (12), and being relatively movable towards and away therefrom sothat a workpiece (29) gripped by the gripping device (17a) can be transferred to the gripping device (18a). There is movable tool carrier means (15 and 16) associated with the headstocks, whereby machining operations can be performed on workpieces held in the gripping devices (17a, 18a). The lathe includes means (25, 26) for monitoring the angular positions of the spindles (17, 18) whereby a rotational datum position of each spindle can be established, and first drive and positioning means (19, 22, 27) for rotating the first spindle (17), and for positioning said spindle (17) angularly in predetermined relation to its rotational datum position, and, second drive and positioning means (21, 23, 28) for rotating said spindle (18) angularly in positioning said spindle (18) angularly in predetermined relartion to its rotational datum position. The invention further resides in methods of transferring a workpiece between spindles 17, 18 in such a lathe. |
