Mechanical-hydraulic control device for controlling the locking and unlocking movements of rotary disk in a rotary disc table workpiece processing apparatus

A mechanical-hydraulic control device for mechanically and hydraulically controlling locking and unlocking movements of an axially and rotatively driven rotary disk forming a table of a rotary-table workpiece processing transfer tool machine having a machine bed, said control device including a mechanical control assembly and a hydraulic control assembly, said mechanical control assembly including a ball recirculating screw coupled to a rotary coupling driven by a motor-reducing unit assembly, said ball recirculating screw being rotatively engaged in a fixed screw nut rigid with an axially movable driving shaft on which said rotary disk is rotatively mounted, said rotary disk having a rotary disk surface facing said machine bed and supporting a first ring gear to be also rotatively driven, said machine bed having a machine bed surface facing said rotary disk and having a second ring gear adapted to engage with and disengage from said first ring gear as said ball recirculating screw is rotatively driven in said fixed screw nut so as to axially move said driving shaft and said rotary disk, thereby respectively locking and unlocking said rotary disk, wherein said hydraulic control assembly of said control device comprises a piston-cylinder assembly including a piston coupled to said rotary disk and a cylinder defined by a chamber formed in said machine bed, said piston comprising an enlarged portion of said shaft which is axially slidably engaged in said cylinder, said axially slidable piston being hydraulically operated to perform a bidirectional slidable movement in said cylinder as to lock and unlock said rotary disk in cooperation with said ball recirculating screw.