Elevator car position indicator for use by visually impaired persons

Claim 1

A car position indicator arranged in a face plate at a car control station for indicating a momentary position of an elevator car with respect to floors served by the car, the car being connected to an elevator control having an output for generating floor address signals representing the floors to a coding circuit having an input connected with the elevator control output and having a plurality of outputs each representing one of the floors, comprising: a plurality of slidable indicating pins arranged in a braille configuration and extending through apertures formed in a face plate of an elevator car control station; a plurality of electromagnets attached to the face plate, each of said electromagnets having an armature connected to one of said indicating pins and having a control connection for receiving electrical power to excite said electromagnet; and a control circuit having a plurality of inputs connected with a plurality of outputs of a coding circuit connected to an elevator control, each of said inputs for receiving a signal representing a floor number of a separate floor served by an elevator associated with the elevator control, said control circuit having a plurality of outputs each being connected with at least one of said control connections for exciting said electromagnets, said control circuit including a plurality of tri-state buffers each having an activating terminal connected with one of said inputs of said control circuit, said tri-state buffers each having an input terminal connected to a voltage source input line and each having an output terminal connected to at least one of said control circuit outputs whereby a signal generated at one of said control signal circuit inputs is transformed into a corresponding floor number in braille represented by at least an associated one of said indicating pins being extended from the face plate by excitation of said associated electromagnet by said control circuit and wherein for an indication of floor numbers from zero through a maximum of nineteen, said plurality of indicating pins includes a first group of four of said indicating pins and a second group of four of said indicating pins, said control circuit outputs representing floor numbers zero through nine being connected to excite said electromagnets associated with said first group of indicating pins, said control circuit outputs representing a units digit of two digit floor numbers from ten through a maximum of nineteen being connected to excite said electromagnets associated with said second group of indicating pins, and including another tri-state buffer having an output terminal connected to said output terminals of said tri-state buffers which control said indicating pins representing the floor number one and a tens digit of the floor number ten, an input terminal connected to said output terminals of said tri-state buffers associated with the floor numbers eleven and above and an activating terminal connected to said control circuit inputs representing the floor numbers eleven and above.