Abstract: A position detecting device for detecting the position of an object (12) movable along a predetermined path of movement, comprising a signal transmission medium (13) extending along the path of movement, a signal generator (15) movable together with said movable object (12), by means of which a signal can be coupled into the signal transmission medium (13), at least one signal receiver (29, 33) at an extraction location in an end portion of said path of movement, a signal propagation time measuring means (35, 37) adapted to determine the signal propagation time between coupling location and extraction location (45), wherein the signal generator (15) is designed to deliver a periodically repeating signal pulse sequence (FIG.

Abstract: A position detecting device for detecting the position of an object (12) movable along a predetermined path of movement, comprising a signal transmission medium (13) extending along the path of movement, a signal generator (15) movable together with said movable object (12), by means of which a signal can be coupled into the signal transmission medium (13), at least one signal receiver (29, 33) at an extraction location in an end portion of said path of movement, a signal propagation time measuring means (35, 37) adapted to determine the signal propagation time between coupling location and extraction location (45), wherein the signal generator (15) is designed to deliver a periodically repeating signal pulse sequence (FIG.

Abstract: A laser disposed on an elevator car is scanned at a uniform rate; one or more pairs of sensors disposed on opposite sides of the hoistway determine the time for the laser to scan from one sensor to the other, from which the vertical distance between the elevator car and a sensor pair is determined, thereby to derive hoistway position, elevator speed and acceleration.

Abstract: A method of adjusting an elevator speed comprising the steps of determining a desired creep period, determining an actual creep period, determining a difference between the desired creep period and the actual creep period, determining a deceleration time for minimizing the difference between the desired creep period and the actual creep period, and adjusting the elevator speed in response to the deceleration time.

Abstract: An apparatus for determining if an elevator car is level with respect to a landing comprises: a first magnet disposed proximate to the landing; a second magnet disposed proximate to the landing; a sensor for providing a level signal in response to detecting a minimum flux region formed by the first and second magnets; and a processor for determining if the elevator is level with respect to the landing in response to the level signal. Each magnet has a first and second magnetic pole. The first and second magnets are adjacently aligned such that the first magnetic pole of the first magnet is adjacent to the first magnetic pole of the second magnet, and the second magnetic pole of the first magnet is adjacent to the second magnetic pole of the second magnet.

Abstract: The main disconnects for energizing a drive motor for an elevator may be controlled by a circuit having a safety chain, an inspection device, a circuit board and a coil for the main disconnect wherein the safety chain provides a safe condition signal to the inspection device which in turn provides a plurality of mode signals to the circuit board which evaluates the mode signals in order to provide a circuit breaker control signal to the circuit breaker coil. In turn, the circuit breaker coil either opens or closes the main disconnect.

Abstract: For controlling the current in an inductive load, the gate current used to fire thyristors in a rectifier is controlled to reach zero at exactly the same time, within a given half-wave, as the current in the inductive load which receives the voltage from the rectifier, keeping gate voltage on as long as thyristor current is on. A discontinuous thyristor converter current signal is detected and used to generate an enable signal in conjunction with a thyristor gate voltage. The enable signal, in synchronism with a power supply line voltage, provides a pair of channeling signals which then, depending upon whether the field current is positive or negative, activate the gate voltages of the thyristors such that the gate voltages end exactly at that time, within a given half-wave, where the generator field current becomes discontinuous.

Abstract: Automatic and manual adjustment of a new elevator system installation is accomplished by means of a service tool for interacting with software resident in the elevator system whereby various control parameters such as the feed forward gain of the drive system, the start time delay for delaying initiation of a start torque profile for bypassing the velocity loop during starting, the polarity of the feedback signals, e.g., armature current, velocity, motor field current, and other parameters, may be adjusted automatically, while others, such as the impedance of an elevator brake, may be adjusted by a technician responding to automatic prompts.

Abstract: Start jerk and acceleration overshoot on elevator starting are reduced by bypassing and delaying application of an elevator closed loop velocity control system. A bypassing starting torque increases the torque of the motor before the onset of motion, at which time the starting torque is leveled off and held constant and the velocity speed reference profile is started. A small creep velocity dictation injected into the closed velocity loop in addition to the starting torque command causes the difference between the speed profile and the sensed speed to be very small during starting. Moreover, by selecting lift brake current in such a way as to promote a smooth brake opening and by selecting an increasing starting torque profile which overcomes the declining brake torque just after the brake begins to open, the torque needed to compensate for the load can be evenly balanced with the release of brake torque.