Photocell position control system

Claim 1

FOLLOW-UP MEANS FOR USE IN RELATIVELY POSITIONING A TABLE CONNECTED ELEMENT AND A FIXED ELEMENT WITH RESPECT TO ONE ANOTHER, INCLUDING REVERSIBLE DRIVE MEANS COMPRISING A PAIR OF WINDINGS FOR CAUSING RELATIVE LONGITUDINAL MOTION BETWEEN SAID ELEMENTS, AN ELECTRICAL AMPLIFIER DEVICE FOR OPERATING SAID WINDINGS, ONE OF SAID ELEMENTS HAVING PLURAL LAMPS FIXED AT EQUALLY SPACED APART POINTS THEREALONG FOR SELECTIVELY EMITTING LIGHT AND THE OTHER OF SAID ELEMENTS COMPRISING AN INDEXING ELEMENT WHICH WITH RESPECT TO EACH SELECTED POINT OF LIGHT HAS A SATISFIED POSITION OF TRANSVERSE ALIGNMENT THEREWITH, MEANS CONNECTED FOR OPERATING SAID AMPLIFIER DEVICE COMPRISING A PAIR OF PHOTOCELLS MOUNTED TO SAID INDEXING ELEMENT TO FACE IN OPPOSITE DIRECTIONS FOR UNEQUALLY RECEIVING SAID LIGHT AND INTRODUCING UNEQUAL RESPECTIVE OUTPUTS TO THE AMPLIFIER DEVICE, AND MEANS CONNECTING SAID REVERSIBLE DRIVE MEANS AND SAID AMPLIFIER DEVICE WHEREBY THE LATTER SELECTIVELY OPERATES SAID WINDINGS TO RELATIVELY MOVE SAID SELECTED LIGHT POINT AND THE INDEXING ELEMENT INTO THEIR SATISFIED POSITION OF TRANSVERSE ALIGNMENT WHEREBY THE OUTPUTS OF THE RESPECTIVE PHOTOCELLS TO THE AMPLIFIER DEVICE EQUALIZE.