IP Library Granted Patent US 7,575,102
Granted Patent B2
US 7,575,102 · App. 10/574,602 · Granted Aug 18, 2009

Safety device of elevator and its operation testing method

Assignee: Mitsubishi Denki Kabushiki Kaisha
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Quick Facts
Patent No.
US 7,575,102
App. No.
10/574,602
Granted
Aug 18, 2009
Kind
B2
Abstract

In an elevator safety device, a brake device puts brakes to brake a car through an operation of a safety relay main contact provided to a safety circuit. When the car stops during normal operations, a safety relay instruction signal for operating the relay main contact to such a direction that the brake device puts brakes is generated from a detection circuit. Then, the detection circuit detects whether or not the safety relay main contact is operated in accordance with the safety relay instruction signal.

Claims (25)

1. An elevator safety device, comprising:

a safety circuit including a safety relay main contact for operating a brake device for braking a car, and a bypass relay main contact that is parallel-connected with the safety relay main contact and that opens during a normal operation; and

a detection circuit for generating, while the car is stopped during the normal operation, a safety relay instruction signal for operating the safety relay main contact in a direction that activates the brake device, and for detecting that the safety relay main contact is operated in response to the safety relay instruction signal.

2. The elevator safety device according to claim 1 , wherein the detection circuit includes a safety relay monitor contact that opens or closes mechanically in conjunction with the safety relay main contact, and the detection circuit detects a state of the safety relay main contact based on a state of the safety relay monitor contact.

3. The elevator safety device according to claim 1 , wherein:

the safety relay main contact closes during the normal operation and opens under an abnormal elevator operation; and

the detection circuit generates, when generating the safety relay instruction signal, a bypass instruction signal for closing the bypass relay main contact prior to the generation of the safety relay instruction signal.

4. The elevator safety device according to claim 3 , wherein the detection circuit includes a bypass relay monitor contact that opens or closes mechanically in conjunction with the bypass relay main contact and detects a state of the bypass relay main contact based on a state of the bypass relay monitor contact.

5. The elevator safety device according to claim 3 , wherein the detection circuit detects whether or not the bypass relay main contact is operated in response to the bypass instruction signal.

6. The elevator safety device according to claim 1 , wherein the detection circuit outputs, when an abnormality of the safety relay main contact is detected, an abnormality detection signal to an elevator controller for controlling an operation of an elevator.

7. A method of testing an operation of an elevator safety device that includes a safety relay main contact for operating a brake device for braking a car, comprising:

detecting a state where the car stops during a normal operation and a bypass relay main contact that is parallel-connected with the safety relay main contact is open;

generating, while the car is stopped, a safety relay instruction signal for operating the safety relay main contact in a direction that that activates the brake device; and

detecting that the safety relay main contact is operated in response to the safety relay instruction signal.

8. The method of testing an operation of an elevator safety device according to claim 7 , wherein the generating and the detecting are performed each time the car stops.

9. The method of claim 7 further comprising:

closing the safety relay during the normal operation and opening the safety relay under an abnormal elevator operation; and

outputting a bypass instruction signal for closing the bypass relay main contact prior to the generating.

10. The method of claim 9 further comprising:

detecting whether the bypass relay main contact is operated in response to the bypass instruction signal.

11. The method of claim 7 further comprising:

opening or closing a bypass relay monitor contact in conjunction with the bypass relay main contact; and

detecting a state of the bypass relay main contact based on a state of the bypass relay monitor contact.

12. The method of claim 7 further comprising:

outputting an abnormality detection signal to an elevator controller when an abnormality of the safety relay main contact is detected.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 29, 2020
From: MITSUBISHI ELECTRIC CORPORATION
To: MUROLET IP LLC
Reel/Frame 053343/0443 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 31, 2008
From: MATSUOKA, TATSUO
To: MITSUBISHI DENKI KABUSHIKI KAISHA
Reel/Frame 020450/0629 →
Continuity (1)
Related Publication 20070007087A1 · Jan 11, 2007