Patents Examined by Lawrence Coubert
  • Patent number: 5131506
    Abstract: A system for controlling operation of an elevator car door includes a torque command output device for outputting a torque command for controlling a car door driving motor on the basis of a difference between a speed command commanding the operating speed of the motor and the actual speed of operation of the motor, a door position detector for detecting the position of the car door in terms of the number of pulses in a pulse train produced by an encoder connected to the motor, and a memory for storing torque limit values as a function of the door position. The system also has a controller which reads the torque limit value corresponding to the car door position detected by the door position detector. The controller then compares the read torque limit value with a torque command output from the torque command output device and generates a reversing instruction to be given to the motor upon determining that the torque command is not smaller than the torque limit value.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: July 21, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masamoto Mizuno, Masanori Tawada, Terumi Hirabayashi, Toshiyuki Kodera