Abstract: In a vertical machining center, a spindle-drive sleeve is axially immovable in the machine frame, but rotates about its longitudinal axis to rotate a spindle mounted in the sleeve for rotation by the sleeve while axially slidable independent of the sleeve. A linear drive, non-rotating ball screw connected to the upper end of the spindle is driven axially by a rotationally powered, axially anchored ball nut to advance and retract the spindle in the sleeve. A drawbar coupling system extends inside the spindle from the top to the bottom to connect to any one of various toolholders in an index disk which is rotatable for positioning toolholders sequentially in line with the spindle axis. A pneumatically actuated drawbar operator shaft extends inside and coaxially with the ball screw from the top to the bottom. The shaft actuator is mounted to the top of the ball screw and drives the shaft axially inside the screw when a toolholder is to be approached for connection.

Abstract: A CNC machine tool control system that includes a controllable, movable tool for shaping a workpiece, a mechanism for receiving control instructions describing shaping functions to be performed on the workpiece, a processing unit and memory. The control systems includes objects defined according to an object oriented design. One type of object is a model of a shaping process to be performed on a workpiece, including informational parameters regarding the physical dimensions of the shape resulting from the process. The process objects communicates through an object oriented messaging system to machine objects, which represent physical devices present on the CNC machine on which the control system operates. The system also includes object oriented motion control and exception handler objects, each of which may communication with other object via object oriented messages.