Lift car position control systems are described which use an elongate code bearing member which runs up and down the lift shaft. The member is preferably fixed though it may move with the lift car and cooperates with a moving or fixed detector respectively. The output of the detector is conveniently fed to a microprocessor which in dependence upon its programming and data concerning the lift and the building in which it is installed emits control signals to control the lift motor. The system is particularly valuable as allowing continuous monitoring of rope wear or stretch, lift car over-loading, acceleration, rope slippage and like operating parameters.
An elevator speed and positioning device includes an elongated member and a rotating disk. The elongated member includes an apparatus for indicating position along the member and the disk includes an apparatus for communicating the indicating apparatus. A constant relationship exists between the elongated member and the disk such that relative positions between the two are repeatable. The relative motion between the elongated member and the disk may be quantified to determine the relative position of the elevator car.
A shaft winding or winch system for raising and lowering a load attached to one end of a rope. The system includes a brake unit for braking a drum, a detection unit for detecting the length of the rope, and a control unit for controlling the brake unit according to the detected extended length of the rope and the torque generated by the drive unit.
A relative position derivation, sensing and indicator system primarily adapted for conventional elevators. The system displays elevator position and travel direction at each floor with a relatively old fashioned appearing indicator apparatus including an "antique" faceplate and a simple rotatable pointer arm driven by a stepper motor assembly. Electronic solid state digital circuitry is employed to derive suitable control signals for driving the associated stepper motors which rotate the pointer arms associated with each position displayed. A plurality of vanes vertically aligned within the hoistway are provided with parallel, offset rows of perforations. A generally U-shaped vane reader traveling with the elevator car establishes a pair of rapidly pulsed, oppositely directed infrared light beams across a void-like channel formed between its sides. Suitable photoresponsive elements in the vane reader may receive and interpret the light pulses to sense the presence or absence of interposed vanes (and vane perforations) to derive digital data during car movement. Correlation means in the vane reader are provided to output two pairs of control signals, which are delivered to an associated drive circuit for correlating and generating a pair of complementary clock signals and a pair of complementary direction signals. A stepper motor processor correlates and processes the last mentioned signals for ultimately controlling associated stepper motor actuation circuits associated with the multiple stepper motors employed in conjunction with the indicator apparatus disposed at each floor.
An actual position value transmitter for an elevator position control circuit includes a pulse transmitter in the form of a digital tachometer which is driven by way of a cable and a car distance counter responsive to the pulses for generating an actual position signal. Stopping errors of the elevator car caused by slip of the cable are avoided by utilizing a correction table in the form of a write-read memory, in which correction values assigned to the floors and corresponding to the stopping errors are stored. The correction table is connected to the car distance counter and on departure of the elevator car from a floor or on passing a floor, a correction value assigned to the next floor is fetched from the correction table and fed to the car distance counter for the purpose of correction of the actual position signal.
A method of adjusting a leveling time of an elevator car is disclosed. The method includes the steps of: moving the elevator car in a hoistway; transmitting a first signal by a first sensor in response to moving the elevator car in the hoistway; beginning a time measurement in response to detecting the first signal; transmitting a second signal by a second sensor in response to moving the elevator car in the hoistway, the second sensor being disposed a predetermined distance from the first sensor; ending the time measurement in response to detecting the second signal; determining a time measurement value in response to ending the time measurement; determining a leveling speed of the elevator car by dividing the predetermined distance between the first sensor and the second sensor by the time measurement value; and adjusting the leveling time in response to determining the leveling speed.
