Method for controlling an elevator

Patent metadata

Field	Value
Publication number	US-2020283261-A1
Application number	US-202016807930-A
Country	US
Kind code	A1
Filing date	Mar 3, 2020
Priority date	Mar 4, 2019
Publication date	Sep 10, 2020
Grant date	—

Abstract

A method includes commanding a brake controller to open a machinery brake, measuring the brake current of the machinery brake, and when the measured brake current does not meet or exceed a predetermined threshold value within a predetermined time period, then generating a signal indicating failure of the machinery brake and cancelling the elevator run sequence, else executing the elevator run sequence.

First claim

1 . A method for controlling an elevator provided with a machinery brake and a machinery brake controller controlling the machinery brake, the method comprising the steps of:
commanding the brake controller to open the machinery brake; measuring the brake current of the machinery brake; and when the measured brake current does not meet or exceed a predetermined threshold value within a predetermined time period, then generating a signal indicating failure of the machinery brake and cancelling the elevator run sequence, else executing the next step in the elevator run sequence.

2 . The method according to claim 1 , wherein, before the commanding step, initiating a new elevator run sequence based on a received service request.

3 . The method according to claim 1 , wherein the predetermined threshold value of the brake current is determined based on a value of the brake current that is needed for opening the specific machinery brake used in the elevator.

4 . The method according to claim 1 , wherein the machinery brake comprises a first brake and a second brake, the method comprising the steps of:
commanding the brake controller to open only the first brake; measuring the brake current of the first brake; and when the measured brake current to the first brake meets or exceeds a predetermined threshold within a predetermined time period, then commanding the brake controller to close the first brake and to open the second brake, else commanding the brake controller to close both the first brake and the second brake, aborting the run and issuing a fault code; measuring the brake current to the second brake; and when the measured brake current to the second brake meets or exceeds the predetermined threshold within the predetermined time period, then commanding the brake controller to open the first brake, else commanding the brake controller to close both the first brake and the second brake, aborting the run and issuing a fault code.

5 . The method according to claim 4 , wherein the ramp torque of the hoisting motor is turned immediately after the brake controller is commanded to open the second brake.

6 . The method according to claim 5 , wherein the speed reference of the hoisting motor is released immediately after the brake controller is commanded to open the first brake.

7 . The method according to claim 1 , wherein the brake current is measured in a common branch supplying current to the brake controller.

8 . The method according to claim 4 , wherein the brake current is measured separately in each branch supplying current from the machinery brake controller to the respective brake.

9 . A method for testing an elevator machinery brake comprising a first brake and a second brake, the method comprising the steps of:
commanding the machinery brake controller to open only the first brake; measuring the brake current of the first brake; measuring the movement of the elevator; when the measured brake current meets or exceeds a predetermined threshold within a predetermined time period and no movement of the elevator is detected, then commanding the machinery brake controller to close both the first brake and the second brake, and indicating a successful passing of the brake test; and when the measured brake current does not meet or exceed the predetermined threshold in the predetermined time period or if movement of the elevator is detected, then commanding the machinery brake controller to close both the first brake and the second brake, aborting the run, and issuing a fault code.

10 . The method according to claim 9 , wherein when the measured brake current does not meet or exceed the predetermined threshold in a predetermined time period, then determining the first brake to be defective.

11 . The method according to claim 9 , wherein when movement of the elevator is detected, then determining the second brake to be defective.

12 . The method according to claim 9 , wherein the method in an automatic brake test comprises a further step in which the brake test is repeated as soon as possible when the machinery brake failed the test until the machinery brake fails three consecutive tests, whereby further runs are prevented.

13 . The method according to claim 9 , wherein the machinery brake test is repeated in the reverse order so that the machinery brake controller is in the first step commanded to open only the second brake.

14 . An elevator comprising:
a main controller; and a machinery brake controller controlling a machinery brake, wherein the main controller controls the elevator according to claim 1 .

15 . A computer program product embodied on a non-transitory computer readable medium, and comprising program instructions, which, when run on a computer, causes the computer to perform the method as claimed in claim 1 .

16 . The method according to claim 2 , wherein the predetermined threshold value of the brake current is determined based on a value of the brake current that is needed for opening the specific machinery brake used in the elevator.

17 . The method according to claim 2 , wherein the machinery brake comprises a first brake and a second brake, the method comprising the steps of:
commanding the brake controller to open only the first brake; measuring the brake current of the first brake; when the measured brake current to the first brake meets or exceeds a predetermined threshold within a predetermined time period, then commanding the brake controller to close the first brake and to open the second brake, else commanding the brake controller to close both the first brake and the second brake, aborting the run and issuing a fault code; measuring the brake current to the second brake; and when the measured brake current to the second brake meets or exceeds the predetermined threshold within the predetermined time period, then commanding the brake controller to open the first brake, else commanding the brake controller to close both the first brake and the second brake, aborting the run and issuing a fault code.

18 . The method according to claim 3 , wherein the machinery brake comprises a first brake and a second brake, the method comprising the steps of:
commanding the brake controller to open only the first brake; measuring the brake current of the first brake; when the measured brake current to the first brake meets or exceeds a predetermined threshold within a predetermined time period, then commanding the brake controller to close the first brake and to open the second brake, else commanding the brake controller to close both the first brake and the second brake, aborting the run and issuing a fault code; measuring the brake current to the second brake; and when the measured brake current to the second brake meets or exceeds the predetermined threshold within the predetermined time period, then commanding the brake controller to open the first brake, else commanding the brake controller to close both the first brake and the second brake, aborting the run and issuing a fault code.

19 . The method according to claim 2 , wherein the brake current is measured in a common branch supplying current to the brake controller.

20 . The method according to claim 3 , wherein the brake current is measured in a common branch supplying current to the brake controller.

Assignees

• Kone Corp

Inventors

• Calcagno Alessio
• Stolt Lauri
• Kangas Petteri
• Jokinen Risto

Classifications

• B66B5/0037

  Performance analysers · CPC title

• B66B5/0031

  for safety reasons · CPC title

• B66B5/02 Primary

  responsive to abnormal operating conditions · CPC title

• B66B1/32 Primary

  effective on braking devices {, e.g. acting on electrically controlled brakes (brake control H02P, lift brakes per se B66B5/02)} · CPC title

• B66B5/0025 Primary

  for maintenance or repair · CPC title