| 摘要 |
A lathe has two tool units for machining a workpiece from both end faces, and a workpiece-gripping drive stock disposed between the two tool units. A single chuck is supported on the drive stock and includes a series of radially displaceable gripping members and two coaxial rings rotatable relative to each other for actuating the gripping members, an outer one of the rings serving as a pulley for a driving belt whereby the outer ring is driven and each one of the two rings having an annular series of coupling teeth at one end face thereof. Two devices for respectively loading and unloading the workpiece each comprises a carrier carrying coupling teeth, the coupling teeth of the two coaxial chuck rings being movable into mesh with the coupling teeth of said devices, the coupling teeth carrier of only one of the devices being rotatable and a motor being connected to the rotatable carrier for rotating the carrier. Axially displaceable collets for gripping the workpiece are aligned on the loading and unloading devices with the axis of the chuck and the collet of the unloading device is adapted to be forced back by pressure from the chuck. An adjustable stop is arranged to be engaged by the collet of the unloading device when it is forced back by the pressure from the chuck. |
