BASAR: A Blackboard Based Software Architecture

A drive system for a multiple spindle machine tool which includes a separate servo motor for powering the drum shaft which serves as the basic control element for the timing and movement of tools which are operable upon the workpieces carried in the spindles. The speed of the servo motor is regulated by a tachometer in a feedback loop to hold the speed of the motor at any chosen value. The drum shaft rotates at either high speed during tool traverse or low or feed speed during machining operations. A second tachometer driven by the spindle drive system generates a signal proportional to the spindle speed and that signal coordinates the low feed speed of the drum shaft with the spindle speed. Conventional clutches for high-speed and reverse operation of the drum shaft are replaced by switches and potentiometers.