METHOD FOR OPERATING AN ELEVATOR FOR MAINTENANCE

Abstract

A method for operating an elevator for maintenance is performed on an elevator having a car, an elevator shaft, wherein the car is displaceable along the elevator shaft, a drive displacing the car, a plurality of shaft doors, at least one of the shaft doors being arranged at each of multiple floors including at least a lowermost floor and a uppermost floor, and an elevator control unit. The elevator control unit performs among others the method steps of: checking whether a person is within a predefined danger zone, wherein the predefined danger zone preferably is the elevator shaft; and switching from the maintenance mode back into a normal operation mode when there is no person within the predefined danger zone.

Claims

1-16. (canceled)

17. A method for operating an elevator for maintenance, wherein the elevator includes a car, an elevator shaft with the car being displaceable along the elevator shaft, a drive for displacing the car, a plurality of shaft doors, at least one of the shaft doors being arranged at each of multiple floors including a lowermost floor and an uppermost floor for opening and closing access to the car, and an elevator control unit, the method comprising the steps of: the elevator control unit receives a start-maintenance-request sent by a technician; the elevator control unit switches from a normal operation mode to a maintenance mode in response to the received start-maintenance-request; the elevator control unit receives a stop-maintenance-request sent by the technician; the elevator control unit checks whether a person is within a predefined danger zone; and the elevator control unit switches from the maintenance mode back into the normal operation mode when the elevator control unit concludes there is no person within the predefined danger zone.

18. The method according to claim 17 wherein the technician sends the start-maintenance-request and the stop-maintenance-request from a mobile electronic device.

19. The method according to claim 17 wherein the predefined danger zone is at least a portion of the elevator shaft.

20. The method according to claim 17 wherein the step of checking whether a person is within the predefined danger zone comprises the steps of: capturing a pre-maintenance-status of the elevator after the start-maintenance-request was received by the elevator control unit and before the elevator control unit switches from the normal operation mode to the maintenance mode and/or capturing a post-maintenance-status of the elevator after the stop-maintenance-request was received by the elevator control unit and before the elevator control unit switches from the maintenance mode back to the normal operation mode; evaluating a difference between two statuses of the elevator by comparing the pre-maintenance-status of the elevator with the post-maintenance-status of the elevator, or comparing the pre-maintenance status with a predefined value for the pre-maintenance-status, or comparing the post-maintenance status with a predefined value for the post-maintenance-status; and concluding that no person is in the predefined danger zone when the evaluated difference is below a predefined threshold.

21. The method according to claim 20 wherein the capturing of the pre-maintenance-status and the post-maintenance-status of the elevator includes measuring values for a pre-maintenance-load and a post-maintenance-load of the car and storing the values in the elevator control unit.

22. The method according to claim 20 wherein the capturing of the pre-maintenance-status and the post-maintenance-status of the elevator includes capturing a snapshot of the elevator shaft with at least one of a camera, a TOF-camera, a thermographic camera and a lidar system.

23. The method according to claim 17 wherein the step of checking whether a person is within the predefined danger zone includes at least one of the steps of: verifying the technician is present within the car or on a floor after the elevator control unit receives the start-maintenance-request from the technician and before the elevator control unit switches from the normal operation mode to the maintenance mode; and verifying the technician is present within the car or on a floor after the elevator control unit receives the stop-maintenance-request from the technician and before the elevator control unit switches from the maintenance mode back into the normal operation mode.

24. The method according to claim 23 wherein verifying the presence of the technician in the car or on a floor is performed by identifying the technician by at least one of: displaying a code on a screen in the car and/or on the floor and requiring the technician to scan the code with a mobile electronic device; and using a camera and/or a near field communication device in the car and/or on the floor to identify the technician.

25. The method according to claim 17 wherein the start maintenance-request sent by the technician is a request to enter the elevator shaft at a specific shaft door, and wherein the method includes a step of displacing the car to a pre-defined position in proximity of the specific shaft door.

26. The method according to claim 17 including a step of restricting displacement of the car in solely: an upward direction when the maintenance mode was requested at the lowermost floor; and/or a downward direction when the maintenance mode was requested at the uppermost floor after the stop-maintenance-request was received by the elevator control unit.

27. The method according to claim 17 wherein at least one of the shaft doors has an active door drive for opening and closing the at least one shaft door and/or an active door lock for locking and unlocking the at least one shaft door and wherein the method further comprises the steps of: unlocking the at least one shaft door by the active door lock and/or opening the at least one shaft door by the active door drive thereby enabling the technician to access the elevator shaft after the maintenance mode was entered; and/or closing the at least one shaft door by the active door drive and/or locking the at least one shaft door by the active door lock thereby preventing the technician access to the elevator shaft before the maintenance mode is left.

28. The method according to claim 17 including assuring that the car is empty after the elevator control unit receives the start-maintenance-request sent by the technician and before the elevator control unit switches from the normal operation mode to the maintenance mode.

29. The method according to claim 17 wherein in the maintenance mode, the elevator control unit prevents the drive from displacing the car and/or an elevator brake is engaged before the technician is granted access to the elevator shaft.

30. The method according to claim 17 including initiating verification of a braking capability after the maintenance mode was left and/or before maintenance mode is entered by performing a static brake test on a brake of the elevator.

31. An elevator comprising: a car displaceable along an elevator shaft; a drive for displacing the car along the elevator shaft; an elevator control unit; a plurality of shaft doors, at least one of the shaft doors being arranged at each of multiple floors, each of the shaft doors having an associated active door drive for opening and closing the shaft door and/or an active door lock that is enabled and disabled by the elevator control unit; and wherein the elevator control unit is adapted to perform the method according to claim 17.

32. A computer program product comprising non-transitory computer readable instructions for performing the method according to claim 17, which instructions: when executed by a processor in the elevator control unit instruct the elevator control unit to perform the method; and when executed by a processor in a data communication device instruct the data communication device to transmit the start-maintenance-request and the stop-maintenance-request.

33. A computer readable medium comprising the computer program product according to claim 32 stored thereon.

34. A method for operating an elevator for maintenance, wherein the elevator includes a car, an elevator shaft with the car being displaceable along the elevator shaft, a drive for displacing the car, a plurality of shaft doors, each of the shaft doors being arranged at an associated one of multiple floors including a lowermost floor and an uppermost floor for opening and closing access to the car, and an elevator control unit, the method comprising the following steps: the elevator control unit receives a start-maintenance-request sent by a technician using a mobile electronic device; the elevator control unit switches from a normal operation mode to a maintenance mode in response to the received start-maintenance-request; the elevator control unit receives a stop-maintenance-request sent by the technician using the mobile electronic device; the elevator control unit checks whether a person is within a predefined danger zone in the elevator shaft; and the elevator control unit switches from the maintenance mode back into the normal operation mode when the elevator control unit concludes there is no person within the predefined danger zone.

35. The method according to claim 34 wherein the step of checking whether a person is within the predefined danger zone comprises the steps of: capturing a pre-maintenance-status of the elevator after the start-maintenance-request was received by the elevator control unit and before the elevator control unit switches from the normal operation mode to the maintenance mode and/or capturing a post-maintenance-status of the elevator after the stop-maintenance-request was received by the elevator control unit and before the elevator control unit switches from the maintenance mode back to the normal operation mode; and evaluating a difference between two statuses of the elevator by, evaluating a difference between the pre-maintenance-status of the elevator and the post-maintenance-status of the elevator and concluding that no person is in the predefined danger zone when the evaluated difference is below a predefined first threshold; and/or evaluating a difference between the pre-maintenance-status of the elevator and a predefined value for the pre-maintenance-status and concluding that no person is in the predefined danger zone when the evaluated difference is below a predefined second threshold; and/or evaluating a difference between the post-maintenance-status of the elevator and a predefined value for the post-maintenance-status and concluding that no person is in the predefined danger zone when the evaluated difference is below a predefined third threshold.

Description

DESCRIPTION OF THE DRAWINGS

[0148] FIG. 1 shows an elevator configured for executing a method for operating the elevator for maintenance according to an embodiment of the invention.

[0149] The FIGURE is only schematic and not to scale. Same reference signs refer to same or similar features.

DETAILED DESCRIPTION

[0150] FIG. 1 shows an elevator 1. The elevator 1 is shown in a side view. Furthermore, a portion of the elevator 1 is shown in a front view, as visualized in a partial view inside a dashed frame line.

[0151] The elevator 1 comprises a car 2 which is displaceable along an elevator shaft 4. The elevator car 2 is held and displaced by a suspension traction means such as a rope or a belt. At its opposite end, the suspension traction means is coupled to a counterweight. The suspension traction means is driven by a drive 6. The drive 6 is controlled by the elevator control unit 12.

[0152] The elevator car 2 comprises a car door 9 for opening and closing an access to the elevator car 2. The car door 9 may be opened and closed actively by a car door drive 29. The car door drive 29 is controlled by the elevator control unit 12.

[0153] At each of multiple floors 10, 10, 10 at least one shaft door 8 is provided. The shaft door 8 may be opened and closed for granting or blocking access to the elevator shaft 4. The elevator 1 presented herein comprises an active door drive 28 at each of the shaft doors 8 for actively opening and closing the respective shaft door 8 by laterally displacing shaft door blades. Each of the door drives 28 is controlled by the elevator control unit 12. It is to be noted, that for reasons of a simpler formation, the term door drive 28 shall refer herein only to the shaft doors 8, not to the car door 9 (which is equipped with a car door drive 29). An active door lock 30 can be provided for locking and unlocking the shaft doors 8.

[0154] Furthermore, at each of the multiple floors, a landing operation panel 13 is provided in proximity to the shaft door 8. For example, such landing operation panel 13 may comprise one or more push buttons which may be actuated by passengers for calling the car 2 to come to their floor.

[0155] During normal operation of the elevator 1, the elevator control unit 12 controls the drive 6 for displacing the car 2 to one of the floors in response to a passenger's call provided by actuating one of the landing operation panels 13. Therein, the drive is controlled such that the car 2 is stopped at the landing position such that its car bottom is substantially on the same height as a bottom at the floor at which the car 2 shall collect or deliver passengers.

[0156] For maintenance purposes, the normal operation of the elevator 1 has to be temporarily interrupted. For such purpose, according to the method proposed herein, the technician 14 may approach the elevator 1 at one of the floors, such as for example the uppermost floor 10. Upon being close to the shaft door 8 at this floor 10, the technician may send a request for maintenance. Such a request is then received by the elevator control unit 12.

[0157] When the elevator control unit 12 has received a maintenance-request sent by the technician 14, the drive 6 will control the displacement of the car 2 to a position such that a roof 41 of the car 2 is adjacent to the shaft door 8 at the floor at which the maintenance work requested in the maintenance-request has to be performed (for example the uppermost floor 10, as shown in FIG. 1). For this maintenance-request, the head 19 equals the predefined danger zone 18. Subsequently, the elevator control unit 12 controls the door drive 28 at the respective floor 10 to actively open the associated shaft door 8. The technician 14 may enter the elevator shaft 4 by stepping on top of the roof 41 of the waiting car 2. At such location, the technician 14 may inspect, modify, repair or replace various components of the elevator 1, such as for example car guide shoes, parts of the elevator control unit, a front bracket fixation, the suspension traction means, a load measuring system and connectors at the counterweight side as well at the car side, counterweight guide shoes, shaft information, a deflection pulley, and/or other components.

[0158] Upon having completed the maintenance, the technician 14 may leave the elevator shaft 4 through the opened shaft door 8. The technician 14 may then send a stop-maintenance-request with a data communication device 32 such as his mobile electronic device 16 which may be received by the elevator control unit 12. Upon receiving the stop-maintenance-request, the elevator control unit 12 may control the door drive 28 of the opened shaft door 8 to close this shaft door 8. The elevator control unit 12 displaces the elevator car in an downward direction after the elevator control unit 12 has closed the shaft door 8. As a next step, the technician 14, who at this time is supposed to be outside of the shaft 4, has to identify himself within the car being positioned one floor 10 below the uppermost floor 10. The elevator control unit 12 therefore opens the respective shaft doors and the car doors so that the technician 14 can enter the car 2 from the floor 10 and identify himself for example at the car operating panel 22, which may include a camera 24. After this identification, the elevator control unit 12 knows that the technician 14, who requested maintenance is not inside the shaft anymore and therefore not within the predefined danger zone, i.e. within the head 19 and safely switches back to normal operation mode.

[0159] In exemplary embodiment a load-measurement-cell 27 implemented at the car-brake 26 may be used to capture a pre-maintenance-status, i.e. pre-maintenance-load-measurement before the maintenance mode is entered and post-maintenance-status, i.e. a post-maintenance-load-measurement before the maintenance mode is left. Before displacing the car to the next lower floor 10 (see paragraph above) the elevator control unit 12 compares the two load measurements to conclude that they are within a predefined range, e.g. 5% of each other. Only if this is concluded, the car 2 is then moved to the lower floor 10, where the method continues as described above, i.e. by identification of the technician 14 inside the car 2.

[0160] When the maintenance-request is such that maintenance at the lowermost floor 10 is requested, the drive 6 will displace the car 2 based on a control of the elevator control unit 12 to a position above the lowermost floor 10, i.e. such that the car bottom is sufficiently above a pit 17 of the elevator shaft 4, for allowing the technician 14 to enter such a pit 17. For this maintenance-request, the pit 17 equals the predefined danger zone 18. Subsequently, the elevator control unit 12 controls the door drive 28 of the lowermost floor 10 to actively open the associated shaft door 8. The technician 14 may then enter the pit 17. In the pit 17, the technician may inspect, modify, repair or replace various components of the elevator 1.

[0161] Upon having received the request for maintenance (start-maintenance-request), the elevator control unit 12 switches to maintenance mode. In such maintenance mode, calls entered by passengers for example one of them at landing operation panels 13 at any of the other floors or at a car operation panel 22 are ignored. Furthermore, any displacement of the car 2 is prevented as long as the elevator control unit 12 is in the maintenance mode.

[0162] In an exemplary, the technician 14 may use a mobile electronic device 16 such as a smartphone to generate and transmit data forming the maintenance-request. For such purpose, a specific application may be programmed and uploaded to the mobile electronic device 16. The electronic mobile device 16 may send electromagnetic waves encrypting the maintenance-request. The electromagnetic waves may be received by a suitable sensor being part or being connected to the elevator control unit 12. Alternatively, the communication link between the mobile electronic device 16 and the elevator control unit 12 could also be established via a server, e.g. a cloud.

[0163] Upon having completed the maintenance, the technician 14 may leave the elevator shaft 4 through the opened shaft door 8. The technician 14 may then send a stop-maintenance-request with his mobile electronic device 16 which may be received by the elevator control unit 12. Upon receiving the stop-maintenance-request, the elevator control unit 12 may control the door drive 28 of the opened shaft door 8 to close this shaft door 8. The elevator control unit 12 displaces the elevator car in an upward direction after the elevator control unit 12 has closed the shaft door 8. As a next step, the technician 14, who at this time is supposed to be outside of the shaft 4, has to identify himself within the car being positioned at the floor 10. The elevator control unit 12 therefore opens the respective shaft doors and the car doors so that the technician 14 can enter the car 2 and identify himself for example at the car operating panel 22, 24. After this identification, the elevator control unit 12 knows that the technician 14, who requested maintenance is not inside the shaft anymore and therefore not within the predefined danger zone, i.e. within the pit 17 and safely switches back to normal operation mode.

[0164] In exemplary embodiment a camera 20 may be implemented at the bottom of the car and may be used to capture a pre-maintenance-status, i.e. pre-maintenance-snapshot before the maintenance mode is entered and post-maintenance-status, i.e. a post-maintenance-snapshot before the maintenance mode is left. Before displacing the car to the next floor 10 (see paragraph above) the elevator control unit 12 compares the two snapshots to conclude that they resemble each other to a degree that the presence of a person in the pit can be negated. Only if this is concluded, the car 2 is then moved to the upper floor 10, where the method continues as described above, i.e. by identification of the technician 14 inside the car 2.

[0165] With the method and elevator 1 proposed herein, maintenance of the elevator 1 may be substantially simplified and may be made more secure. Upon sending a start-maintenance-request, the shaft door 8 at the floor where the technician 14 has requested maintenance may be opened actively and automatically. Furthermore, the car 2 has already previously been driven to a suitable location. As during maintenance mode, no further displacement of the car 2 is allowed and risk of injury for the technician is minimized. Furthermore, there is no need for any control unit on the car roof or in the pit 17. Generally, there is also no need for any toe guard on the car roof 41 and/or for an apron on a car sill. Accordingly, costs for such equipment may be saved.

[0166] Finally, it should be noted that the term comprising does not exclude other elements or steps and the a or an does not exclude a plurality. Also elements described in association with different embodiments may be combined.

[0167] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.