High and low speed leveling control for an elevator with tach speed sensor

Claim 1

A CONTROL SYSTEM FOR AN ELEVATOR CAR ADAPTED TO TRAVEL BETWEEN A PLURALITY OF FLOORS, COMPRISING A CONTROLLABLE ELECTRICAL GENERATING MEANS FOR RAISING AND LOWERING THE ELEVATOR CAR AT SELECTIVELY VARIABLE SPEEDS, SELECTIVELY OPERABLE LEVELING AND BRAKING MEANS FOR EFFECTING A CONTROLLED STOP AT A SELECTED FLOOR AS THE CAR TRAVELS FROM ONE FLOOR TO ANOTHER INCLUDING SELECTIVELY OPERABLE HIGH SPEED LEVELING MEANS AND LOW SPEED LEVELING MEANS FOR CONTROLLING SAID ELECTRICAL GENERATING MEANS, MEANS RESPONSIVE TO THE OPERATION OF SAID DRIVE MEANS FOR PRODUCING AN ELECTRICAL OUTPUT SIGNAL REPRESENTATIVE OF THE SPEED OF THE ELEVATOR CAR, SELECTIVELY ENERGIZABLE COMPENSATING MEANS RESPONSIVE TO SAID ELECTRICAL OUTPUT SIGNAL AND TO THE DIRECTION OF TRAVEL OF THE ELEVATOR CAR FOR MODIFYING THE SPEED CONTROL OF SAID ELECTRICAL GENERATING MEANS, MEANS RESPONSIVE TO THE OPERATION OF SAID HIGH SPEED LEVELING MEANS FOR INITIATING THE OPERATION OF SAID COMPENSATING MEANS, MEANS RESPONSIVE TO THE OPERATION OF SAID LOW SPEED LEVELING MEANS FOR VARYING THE OPERATION OF SAID ELECTRICAL OUTPUT SIGNAL PRODUCING MEANS TO MODIFY THE OPERATION OF SAID COMPENSATING MEANS, MEANS FOR CONTROLLING THE ENERGIZATION OF SAID COMPENSATING MEANS AS A FUNCTION OF THE DIRECTION OF TRAVEL OF THE ELEVATOR CAR, AND IMPEDANCE MATCHING MEANS INTERPOSED BETWEEN SAID ELECTRICAL OUTPUT SIGNAL PRODUCING MEANS AND SAID COMPENSATING MEANS.