MACHINE TOOL

摘要

In a machine tool having the spindle (110) supporting a work holder (350), means are provided for automatically operating the work holder to grip or release a workpiece and for automatically securing the work holder to the spindle or release it therefrom. Within the spindle, a compression spring (116C) acts on a slide (116B) which has claws (116) gripping a head (157) provided at one end of a holder housing (152) to draw the latter into engagement with a conical socket (115) of the spindle thereby to secure the holder. Within the holder housing (152), a compression spring (159B) urges a set of jaws (158A) into a conical socket (152A) of the housing (152) thereby to grip a workpiece (51). A hydraulic actuator (M316) mounted on fixed structure (102) is adapted both for opening the jaws and for releasing the holder from the spindle. For opening the jaws, a piston (M316B) of the actuator is moved through an initial distance X thereby to move the jaws in opposition to the spring (159B) in the opening sense. The piston acts through the intermediary of a rod (317) supported in the slide (116B) for free movement relative thereto. For release of the holder from the spindle, the piston is moved further, through a distance Y, to engage and move the slide in the sense causing the claws (116) to abut a shoulder (155B) on the holder housing and release the holder from the socket (115). Toward the end of the piston movement the claws spring radially outwards into a recess (110C) of the spindle to free the holder for removal by an automatic transfer mechanism. Several modifications are described.