Photocell position detector for elevator cars including a perforated tape uniquely encoded for each position with responsive control means

Claim 1

IN COMBINATION WITH AN ELEVATOR CAR ARRANGED FOR VERTICAL MOVEMENT IN A HOISTWAY AND SERVING A PLURALITY OF LANDINGS, A PLURALITY OF ELECTRIC SIGNAL PRODUCING MEANS, EACH HAVING TWO OUTPUT TERMINALS, MEANS RESPONSIVE TO CAR MOVEMENT FOR SELECTIVELY ENERGIZING SAID SIGNAL PRODUCING MEANS IN PREDETERMINED BINARY CODED COMBINATIONS CORRESPONDING TO THE LOCATION OF SAID CAR AT PRESELECTED POSITIONS IN SAID HOISTWAY, DIODE MATRIX MEANS HAVING A PLURALITY OF INPUT TERMINALS ELECTRICALLY CONNECTED TO SAID OUTPUT TERMINALS OF SAID SIGNAL PRODUCING MEANS AND ALSO HAVING A PLURALITY OF OUTPUT TERMINALS, ONE FOR EACH OF SAID PRESELECTED POSITIONS, SAID DIODE MATRIX MEANS BEING ARRANGED TO DECODE SAID PREDETERMINED CODED COMBINATIONS BY SELECTIVELY PRODUCING IN RESPONSE THERETO ELECTRICAL SIGNALS AT SAID MATRIX OUTPUT TERMINALS IN ACCORDANCE WITH THE CORRESPONDING LOCATION OF SAID CAR, AND ENABLING MEANS WITH TWO OUTPUT TERMINALS RESPONSIVE TO THE LOCATION OF SAID CAR OUTSIDE A PREDETERMINED REGION LOCATED AT EACH SAID PRESELECTED POSITION TO PREVENTE SAID DIODE MATRIX MEANS FROM DECODING NOTWITHSTANDING THE PRODUCTION OF ONE OF SAID PREDETERMINED CODED COMBINATIONS, SAID ENABLING MEANS BEING OPERABLE WHEN THE CAR ENTERS ANY ONE OF SAID PREDETERMINED REGIONS TO ENABLE SAID DIODE MATRIX MEANS TO DECODE THE PREDETERMINED CODED COMBINATION PRODUCED FOR THE POSITION AT WHICH THE CAR IS LOCATED, EACH OF SAID ELECTRICAL SIGNAL PRODUCING MEANS AND SAID ENABLING MEANS INCLUDING A UNIDIRECTIONAL POWER SOURCE AND A PHOTOSENSITIVE SWITCH, EACH SAID SWITCH INCLUDING A PHOTOSENSITIVE CELL HAVING A CERTAIN RESISTIVE IMPEDANCE WHICH IN RESPONSIVE TO LIGHT STRIKING SAID CELL IS SUBSTANTIALLY REDUCED, EACH SAID SWITCH BEING OPERABLE FROM A FIRST CONDITION TO A SECOND CONDITION BY LIGHT STRIKING SAID CELL AND BACK TO SAID FIRST CONDITION WHEN SAID CELL IN SHIELDED FROM LIGHT, EACH SAID SWITCH WHEN IN SAID FIRST CONDITION CONNECTING SAID POWER SOURCE TO ITS ASSOCIATED OUTPUT TERMINALS IN A FIRST CERTAIN MANNER AND WHEN OPERATED TO SAID SECOND CONDITION INTERCHANGING AND CONNECTION OF SAID POWER SOURCE TO ITS ASSOCIATED OUTPUT TERMINALS.