Nova Patents
EP0959222A2

Fire door operator

Abstract

A fire door opener or operator (10) according to the invention includes a DC brake solenoid (632) coupled to an AC motor drive system (12) with an inline gear reducer. If AC power is lost, the brake can be controlled by an electronically controlled descent device and the battery backup power. If the brake is disengaged, the door (20) will drop by overcoming the internal inertia and friction in the inline gear reducer. A method for electronically controlling the descent speed of a fire door with or without AC power or motor control is also described. Speed of descent is controlled electronically by measuring the descent speed of the fire door (20) at its limit shaft and electrically modulating the brake engagement using the DC solenoid (632).

EP0959222A2, drawing sheet 1
Sheet 1 of 17

Term

Term ended

Projected expiry passed 24 March 2019, 7.5 years ago.

  1. Priority
  2. Filed
  3. Published
  4. Projected expiry
  5. Today

13 claims: 3 independent, 10 dependent

  1. 1
    An operator for operating a fire door, the fire door having a drive shaft, comprising:a motor having an output shaft coupled to the drive shaft;a brake for holding the fire door in an open or a closed condition;an electronically controlled descent device comprising: a DC solenoid for engaging and disengaging the brake;a speed sensor for detecting a descent speed of the fire door;and an electronic controller, responsive to the speed sensor, selectively enabling the DC solenoid when the descent speed reaches a predetermined minimum speed and disabling the DC solenoid when the descent speed reaches a predetermined maximum speed;a limit shaft coupled to the output shaft for setting open limit and closed limit positions;and a DC power source for providing power to the electronically controlled descent device.
  2. 12
    An operator for operating a fire door, the fire door having a drive shaft, comprising:a motor having an output shaft coupled to the drive shaft;a brake for holding the fire door in an open or a closed condition;an electronically controlled descent device comprising: a DC solenoid for engaging and disengaging the brake;a speed sensor for detecting a descent speed of the fire door;and an electronic controller, responsive to the speed sensor, selectively enabling the DC solenoid when the descent speed reaches a predetermined minimum speed and disabling the DC solenoid when the descent speed reaches a predetermined maximum speed;a DC power source for providing power to the electronically controlled descent device;time delay circuitry for delaying descent of the fire door a time delay period after receipt of an alarm signal;and apparatus for adjusting the time delay period.
  3. 13
    An operator for operating a fire door, the fire door having a drive shaft, comprising:a motor having an output shaft coupled to the drive shaft;a brake for holding the fire door in an open or a closed condition;an electronically controlled descent device comprising: a DC solenoid for engaging and disengaging the brake;a speed sensor for detecting a descent speed of the fire door;and an electronic controller, responsive to the speed sensor, selectively enabling the DC solenoid when the descent speed reaches a predetermined minimum speed and disabling the DC solenoid when the descent speed reaches a predetermined maximum speed;a DC power source for providing power to the electronically controlled descent device;and circuitry for selecting an alarm contact type of an external alarm system for sending an alarm close command to the operator.