METHOD FOR PERFORMING AN EMERGENCY STOP, AND A SAFETY ARRANGEMENT OF AN ELEVATOR

• US 20160167921A1
• Filed: 02/23/2016
• Published: 06/16/2016
• Est. Priority Date: 09/10/2013
• Status: Active Grant

• Current Assignee: Kone Corporation
• Original Assignee: Kone Corporation
• Inventors: Hovi, Antti, Kattainen, Ari, Kangas, Petteri, Stolt, Lauri
• Granted Patent: US 10,196,237 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B66B 1/24 Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration
• CPC Class Codes: B66B 1/30 effective on driving gear , e.g. acting on power electronics, on inverter or rectifier controlled motor
• CPC Class Codes: B66B 1/32 effective on braking devices , e.g. acting on electrically controlled brakes brake control H02P, lift brakes per se B66B5/02
• CPC Class Codes: B66B 5/0031 for safety reasons
• CPC Class Codes: B66B 5/02 responsive to abnormal operating conditions
• CPC Class Codes: B66B 5/04 for detecting excessive speed

Abstract

A method for performing an emergency stop with an elevator and a safety arrangement of an elevator are disclosed. In the method, when an emergency stop criterion is fulfilled, the elevator car is driven with the electric motor of the hoisting machine to a stop with a given deceleration profile.

Claims

1-18. -18. (canceled)

19. A method for performing an emergency stop with an elevator, said method comprising the steps of:

when an emergency stop criterion is fulfilled, driving the elevator car with an electric motor of a hoisting machine to a stop with a given deceleration profile;

forming at least two deceleration profiles with different maximum decelerations; and

selecting the deceleration profile to be used from the at least two deceleration profiles on the basis of the state of the safety circuit of the elevator.

20. The method according to claim 19, further comprising the step of connecting a machinery brake to brake the traction sheave of the hoisting machine of the elevator at the same time as the elevator car is driven with the electric motor of the hoisting machine to a stop.

21. The method according to claim 19, further comprising the step of measuring the movement of the elevator car during an emergency stop.

22. The method according to claim 20, further comprising the steps of:

measuring the deceleration of the traction sheave;

if the deceleration of the traction sheave is excessive, driving against the brake with the electric motor in such a way that the deceleration of the traction sheave remains according to the given deceleration profile.

23. The method according to claim 21, further comprising the steps of:

determining a threshold value for limiting the permitted movement of the elevator car;

connecting a second machinery brake to brake the traction sheave of the hoisting machine of the elevator; and

disconnecting a power supply to the electric motor of the hoisting machine of the elevator, if a movement of the elevator car during an emergency stop differs from the permitted movement by more than the threshold value.

24. The method according to claim 19, further comprising the steps of:

monitoring the slipping of the hoisting roping on the traction sheave during an emergency stop;

if the magnitude of the slipping exceeds the threshold value, reducing the deceleration of the elevator car in the deceleration profile.

25. The method according to claim 19, wherein the emergency stop criterion is one or more of the following:

an electricity outage;

the opening of a safety contact of the elevator;

overspeed of the elevator car; and

excessive acceleration or deceleration of the elevator car.

34. The method according to claim 20, further comprising the step of measuring the movement of the elevator car during an emergency stop.

35. The method according to claim 21, further comprising the steps of:

measuring the deceleration of the traction sheave; and

if the deceleration of the traction sheave is excessive, driving against the brake with the electric motor in such a way that the deceleration of the traction sheave remains according to the given deceleration profile.

36. The method according to claim 22, further comprising the steps of:

deteimining a threshold value for limiting the permitted movement of the elevator car;

connecting a second machinery brake to brake the traction sheave of the hoisting machine of the elevator; and

disconnecting the power supply to the electric motor of the hoisting machine of the elevator, if a movement of the elevator car during an emergency stop differs from the permitted movement by more than the threshold value.

37. The method according to claim 20, further comprising the steps of:

monitoring the slipping of the hoisting roping on the traction sheave during an emergency stop; and

if the magnitude of the slipping exceeds the threshold value, reducing the deceleration of the elevator car in the deceleration profile.

38. The method according to claim 21, further comprising the steps of:

monitoring the slipping of the hoisting roping on the traction sheave during an emergency stop; and

if the magnitude of the slipping exceeds the threshold value, reducing the deceleration of the elevator car in the deceleration profile.

26. A safety arrangement of an elevator, comprising:

an elevator car;

hoisting roping of the elevator car;

a hoisting machine, comprising an electric motor and a traction sheave, via which the hoisting roping of the elevator car travels;

a controller, configured to regulate the movement of the elevator car by supplying current to the electric motor of the hoisting machine; and

a monitoring unit configured to determine the operating state of the elevator and to compare the determined operating state to one or more emergency stop criteria, the monitoring unit being configured, when one or more emergency stop criteria are fulfilled, to form an emergency stop command for the controller,

wherein the emergency stop command comprises a specification of the state of the safety circuit

wherein the controller comprises a processor for forming a deceleration profile,

wherein the controller is configured to form at least two deceleration profiles with different maximum decelerations,

wherein the controller is configured to select from the deceleration profiles the deceleration profile to be used during the emergency stop on the basis of the emergency stop command, and

wherein the controller is configured to drive the elevator car with the electric motor of the hoisting machine to a stop with a deceleration profile to be formed in response to an emergency stop command.

27. The safety arrangement according to claim 26, wherein the hoisting machine comprises at least two machinery brakes for braking the traction sheave of the hoisting machine, and wherein the controller is configured to connect only one of the machinery brakes to brake the traction sheave of the hoisting machine of the elevator at the same time as the elevator car is driven with the electric motor of the hoisting machine to a stop.

28. The safety arrangement according to claim 26, wherein the controller is configured to determine the deceleration of the elevator car.

29. The safety arrangement according to claim 28, wherein the controller is configured to connect a machinery brake to brake the traction sheave of the hoisting machine of the elevator at the same time as the elevator car is driven with the electric motor of the hoisting machine to a stop, if the deceleration of the elevator car during the emergency stop falls below the threshold value.

30. The safety arrangement according to claim 26, wherein the monitoring unit is configured to determine the speed of the elevator car and to connect a machinery brake and to disconnect the power supply to the electric motor of the hoisting machine of the elevator when the speed of the elevator car during the emergency stop falls below the threshold value.

31. The safety arrangement according to claim 26, wherein the controller is configured:

to determine the deceleration of the traction sheave; and

to drive with the electric motor against the brake in such a way that the deceleration of the traction sheave remains according to the given deceleration profile, if the determined deceleration of the traction sheave is excessive.

32. The safety arrangement according to claim 27, wherein a threshold value for limiting the permitted movement of the elevator car is recorded in the memory of the monitoring unit, and;

wherein the monitoring unit is configured to connect a second machinery brake to brake the traction sheave of the hoisting machine of the elevator and to disconnect the power supply to the electric motor of the hoisting machine of the elevator, if a movement of the elevator car during an emergency stop differs from the permitted movement by more than the threshold value.

33. The safety arrangement according to claim 26, wherein an emergency stop criterion is one or more of the following:

an electricity outage;

the opening of a safety contact of the elevator;

overspeed of the elevator car; and

excessive acceleration or deceleration of the elevator car.