Release mechanism and method with alarm circuit

• US 5,082,316 A
• Filed: 12/14/1990
• Issued: 01/21/1992
• Est. Priority Date: 12/01/1989
• Status: Expired due to Fees

• Current Assignee: The Cookson Company
• Original Assignee: The Cookson Company
• Inventors: Wardlaw, Russell
• Primary Examiner(s): MOORE, RICHARD
• Application Number:
  US07/628,615
• Time in Patent Office: 403 Days
• Field of Search: 292/92, 292/201, 292/DIG. 36, 292/336.3, 292/144, 292/345, 160/209, 160/170, 160/133
• US Class Current: 292/201
• CPC Class Codes: E05B 2047/0076 Current to lock only, i.e. "fail-safe"
• CPC Class Codes: E05B 47/0002 with electromagnets
• CPC Class Codes: E05B 47/0006 having a non-movable core; with permanent magnet
• CPC Class Codes: E05B 47/0607 the detent moving pivotally or rotatively
• CPC Class Codes: E05C 17/00 Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith combined with hinges E05D11/00; combined with operating apparatus for wings E05F; other braking devices, stops, buffers E05F5/00
• CPC Class Codes: Y10S 292/36 Overhead door latches
• CPC Class Codes: Y10T 292/1082 Motor

Abstract

Release mechanism and method for fire doors and the like. The door is normally held in an open position by an electrically energized actuator and is released for closing upon deenergization of the actuator. An eneergizing current is supplied to the actuator from a source to energize the actuator, and a limited amount of energy from the source is stored in an element such as a capacitor. Upon interruption of the current from the source to the actuator, the actuator is energized with the stored energy to prevent the door from closing for a limited period of time after the current is interrupted. An alarm circuit is included in some embodiments to porivde a warning when the current has been interrupted and the door is about to close.

Claims

1. In a release mechanism:

a retaining member, electrically operated means for holding the retaining member in a holding position when energized and for releasing the retaining member from the holding position when deenergized, an alarm device, a source for supplying an energizing current to the electrically operated means, and means connected to the source and to the electrically operated means and to the alarm device for storing a limited amount of energy from the source and delivering an energizing current to the electrically operated means and to the alarm device for a limited period of time after interruption of the current from the source.

2. The mechanism of claim 1 wherein the means for storing energy and delivering current comprises a capacitor.

3. The mechanism of claim 1 wherein the means for storing energy and delivering current comprises a first capacitor connected to the electrically operated means and a second capacitor connected to the alarm device.

4. In a release mechanism:

a retaining member, an electrically energized coil for magnetically holding the retaining member in a holding position when energized and for releasing the retaining member from the holding position when deenergized, a source for supplying an energizing current to the coil, a first capacitor connected to the source and to the coil for storing energy from the source and delivering an energizing current to the coil for a limited period of time after interruption of the current from the source, an alarm device, a second capacitor for storing energy from the source, and means for delivering an energizing current from the second capacitor to the alarm device in response to an interruption of current from the source.

5. In combination:

a door movable between open and closed positions, means urging the door toward its closed position, a retaining member connected to the door for holding the door in its open position, electrically operated means for holding the retaining member in a holding position when energized and for releasing the retaining member from the holding position when deenergized, an alarm device, a source for supplying an energizing current to the electrically operated means, and means connected to the source and to the electrically operated means and to the alarm device for storing a limited amount of energy from the source and delivering an energizing current to the electrically operated means and to the alarm device for a limited period of time after interruption of the current from the source.

6. The combination of claim 5 wherein the means for storing energy and delivering current comprises a capacitor.

7. The combination of claim 5 wherein the means for storing energy and delivering current comprises a first capacitor connected to the electrically operated means and a second capacitor connected to the alarm device.

8. In method of operating a release mechanism having a retaining member, an electrically operated actuator for holding the retaining member in a holding position when energized and for releasing the retaining member from the holding position when deenergized, and an electrically actuated alarm device, the steps of:

supplying an energizing current to the actuator from a source to energize the actuator, storing a limited amount of energy from the source, interrupting the delivery of current from the source to the actuator, energizing the actuator with a portion of the stored energy to prevent release of the retaining member for a limited period of time after the current is interrupted, and actuating the alarm device with a portion of the stored energy when the current is interrupted.

9. The method of claim 8 wherein the energy is stored in a capacitor.

10. The method of claim 8 wherein the portion of the energy with which the actuator is energized is stored in a first capacitor, and the portion of the energy with which the alarm device is actuated is stored in a second capacitor.

11. In a release mechanism:

a retaining member, electrically controlled means for holding the retaining member in a holding position, an alarm device, a source of electrical energy, storage means for storing energy from the source, means responsive to an interruption of current from the source for supplying energy from the storage means to the electrically controlled means to cause the retaining member to be released from the holding position a predetermined time after the interruption, and means responsive to the interruption for supplying an operating current from the storage means to the alarm device to actuate the alarm device before the retaining member is released from the holding position.

12. The release mechanism of claim 11 wherein the storage means comprises a first capacitor for supplying energy to the electrically controlled means and a second capacitor for supplying the operating current to the alarm device.

13. The release mechanism of claim 11 wherein the means for supplying the operating current from the storage means to the alarm device comprises a relay having a set of normally closed contacts connected between the storage means and the alarm device, and an operating coil energized by current from the source for holding the contacts in an open position until the current from the source is interrupted.

14. In combination:

a door movable between open and closed positions, means urging the door toward its closed position, a retaining member connected to the door and having a holding position for holding the door in its open position, electrically controlled means for holding the retaining member in its holding position, an alarm device, a source of electrical energy, storage means for storing energy from the source, means responsive to an interruption of current from the source for supplying energy from the storage means to the electrically controlled means to cause the retaining member to be released from its holding position a predetermined time after the interruption, and means responsive to the interruption for supplying an operating current from the storage means to the alarm device to actuate the alarm device before the retaining member is released from its holding position.

15. The combination of claim 14 wherein the storage means comprises a first capacitor for supplying energy to the electrically controlled means and a second capacitor for supplying the operating current to the alarm device.

16. The combination of claim 14 wherein the means for supplying the operating current from the storage means to the alarm device comprises a relay having a set of normally closed contacts connected between the storage means and the alarm device, and an operating coil energized by current from the source for holding the contacts in an open position until the current from the source is interrupted.

17. In method of operating a release mechanism having a retaining member, an electrically operated actuator for moving the retaining member between holding and releasing positions, and an electrically actuated alarm device, the steps of:

storing energy from a power source, detecting an interruption of current from the source, energizing the actuator with a portion of the stored energy so that the retaining member moves to the releasing position a predetermined time after the current is interrupted, and actuating the alarm device with a portion of the stored energy when the current is interrupted.

18. The method of claim 17 wherein the energy is stored in a capacitor.

19. The method of claim 17 wherein the portion of the energy with which the actuator is energized is stored in a first capacitor, and the portion of the energy with which the alarm device is actuated is stored in a second capacitor.