Apparatus for transferring articles through various processing sectors of a manufacturing system

Claim 1

Apparatus for positioning a moveable member comprising: A. track means for controlling the movement of said moveable member along a predetermined path; B. means for reversibly driving said member along said path through and to any one of a plurality of locations thereon; C. means for continuously generating a first analog signal representing the location of said member along any point of said path including any point between and at said locations; D. means for generating a second analog signal corresponding to a specified new location for said member along said path; E. means for continuously generating a difference signal, from said first and second signals representative of the distance and direction of said member from and to, respectively, said new location with said drive means responsive thereto for moving said member to said new location; F. means to stop said member at said desired location; G. wherein said second signal generating means comprises an address circuit means for generating a digitally coded electrical signal specifying a said desired new location for said member, and for converting said digitally coded electrical signal to a representative said second analog signal; H. wherein said first signal generating means comprises a motion sensing means coupled to said drive means for continuously producing said first analog signal representing the position of said member along any point of said path; I. whereiN said summing means comprises a summing amplifier for generating said difference signal amplifier; and J. including means for generating a tolerance signal representing permissible deviation of said member from coincidence with a said desired location; means for comparing said difference signal with said tolerance signal and generating a coincidence signal therebetween; and means responsive to said coincidence signal to activate said stopping means; K. wherein said activating means comprises means for generating a fine tolerance signal representing a smaller permissible deviation of said member from coincidence with said specified location; position representing stop means comprising a magnet at each said desired location along said path; means on said member for sensing said magnet and generate a fine difference signal therebetween; means for comparing said fine difference signal with said fine signal and on coincidence therebetween generating a stop signal for said drive means.