Safety arrangement for an elevator, elevator and method of operating elevator shaft lighting

Abstract

The safety arrangement for an elevator comprises landing door monitoring means (1) configured to monitor the state of the landing doors (5) of an elevator shaft to detect opening of a landing door (5), car door monitoring means (2) configured to monitor the state of elevator car doors (7) to detect opening of an elevator car door (7), and control means (3) operatively connected to the landing door monitoring means (1) and to the car door monitoring means (2) to receive information on the state of the landing doors (5) and the elevator car doors (7). The control means (3) are configured to determine, based on the monitoring of the state of the landing doors (5) and the state of the elevator car doors (7), whether a shaft access condition is present, and to switch on shaft lighting (4) when a shaft access condition is detected.

Description

[0001] SAFETY ARRANGEMENT FOR AN ELEVATOR, ELEVATOR AND METHOD OF OPERATING ELEVATOR SHAFT LIGHTING

[0002] Technical field of the invention

[0003] The invention concerns a safety arrangement for an elevator that comprises an elevator shaft having two or more landing doors and an elevator car, as defined in claim 1 . The invention also concerns an elevator and a method of operating the lighting of an elevator shaft. of the invention

[0004] Elevator shafts need to be provided with sufficient lighting to allow safe working in the elevator shaft. A need to access the elevator shaft is encountered relatively seldom, and for energy saving reasons it is normally not feasible to keep the lighting constantly switched on.

[0005] Different arrangements for operating elevator shaft lighting are known. One commonly used arrangement utilizes switches placed close to each access point to shaft working areas. A drawback of this arrangement is that in certain situations, such as when people are rescued from an elevator car, the shaft may need to be accessed outside of the specified working areas. Consequently, the shaft lighting cannot be switched on from the location where the shaft is accessed.

[0006] Another known solution is arranging light switches in the pit and / or in the machine room of the elevator. Also in this solution the lights cannot always be switched on from the location where the shaft is accessed. This problem has been addressed in some known solutions by providing a rope that extends over the whole length of the elevator shaft and is connected to a light switch. This allows switching on the shaft lighting from any location of the elevator shaft. A drawback of the solution is that the shaft lighting needs to be switched on and off manually and the rope increases the complexity of the installation of the elevator.

[0007] Summary of the invention

[0008] An object of the invention is to provide an improved safety arrangement for an elevator that comprises an elevator shaft having two or more landing doors and an elevator car. Further objects of the invention are to provide an elevator comprising such a safety arrangement and a computer-implemented method of operating lighting of an elevator shaft.

[0009] The safety arrangement according to the invention comprises

[0010] - landing door monitoring means configured to monitor the state of the landing doors of the elevator shaft to detect opening of a landing door,

[0011] - car door monitoring means configured to monitor the state of elevator car doors to detect opening of an elevator car door, and

[0012] - control means operatively connected to the landing door monitoring means and to the car door monitoring means to receive information on the state of the landing doors and the elevator car doors.

[0013] The control means are configured to determine, based on the monitoring of the state of the landing doors and the state of the elevator car doors, whether a shaft access condition is present, and to switch on shaft lighting when a shaft access condition is detected.

[0014] The method according to the invention comprises the steps of

[0015] - monitoring the state of the landing doors of the elevator shaft to detect opening of a landing door,

[0016] - monitoring the state of the elevator car doors to detect opening of an elevator car door,

[0017] - based on the monitoring of the state of the landing doors and the state of the elevator car doors, determining whether a shaft access condition is present, and

[0018] - when a shaft access condition has been detected, switching on the shaft lighting.

[0019] The safety arrangement according to the invention is thus configured to detect situations in which the elevator shaft can be accessed, and to automatically switch on the shaft lighting. This increases the safety of the people working in the elevator shaft, as the shaft lighting is always switched on when a landing door is open and provides access to the elevator shaft. The safety of the elevator is increased also in case of unauthorized opening of a landing door, as a possible falling risk can be noticed more easily due to the shaft lighting. According to an embodiment of the invention, the control means are configured to determine that a shaft access condition is present if opening of an elevator car door is not detected within a predetermined period of time after opening of a landing door. According to an embodiment of the invention, the predetermined period of time is less than 2 seconds. The landing doors of an elevator are typically arranged to be coupled to the elevator car doors such that when the elevator car is positioned at a landing and the elevator car doors are opened, the respective landing doors are automatically opened. Simultaneous opening of the car doors and landing doors thus indicates that the elevator is located at a landing and the opening of the landing doors does not create a shaft access condition. If the landing doors and car doors are not opened simultaneously, it is an indication that both the landing doors and car doors have been opened manually, and a shaft access condition may be present.

[0020] According to an embodiment of the invention, the control means are configured to switch off the shaft lighting a predetermined time after the elevator has been switched to a normal operating mode. If a shaft access condition is detected, normal operation of the elevator is prevented. After resetting of the safety circuits of the elevator, normal operation of the elevator is allowed and the shaft lighting can be automatically switched off.

[0021] According to an embodiment of the invention, the landing door monitoring means comprise a landing door safety circuit that is provided with a switch or a sensor for each landing door of the elevator shaft to detect opening of a landing door.

[0022] According to an embodiment of the invention, the car door monitoring means comprise a switch or a sensor to detect opening of an elevator car door.

[0023] According to an embodiment of the invention, the control means comprise an elevator control unit, such as a safety controller, and / or a dedicated shaft lighting control unit.

[0024] According to an embodiment of the invention, the car door monitoring means are configured to communicate with the control means via a control unit of the elevator car. According to an embodiment of the invention, the control means are configured to control a relay for switching on the shaft lighting.

[0025] According to an embodiment of the invention, the relay is additionally controllable by means of one or more manually operable switches or pushbuttons.

[0026] Brief of the

[0027] Embodiments of the invention are described below in more detail with reference to the accompanying drawings, in which

[0028] Fig. 1 shows schematically an elevator according to an embodiment of the invention,

[0029] Fig. 2 shows as a block diagram the safety arrangement according to an embodiment of the invention, and

[0030] Fig. 3 shows as a flowchart the method according to the invention.

[0031] Detailed description of embodiments of the invention

[0032] Figure 1 shows schematically a simplified view of an elevator. The elevator comprises an elevator shaft. An elevator car 6 is arranged in the elevator shaft and the elevator car 6 is moveable in the elevator shaft in the vertical direction by means of a hoisting member (not shown). The elevator car 6 is provided with one or more elevator car doors 7 providing access into the elevator car 6. The elevator shaft is provided with two or more landings and each landing is provided with at least one landing door 5. The elevator car 6 can move between the landings. All the landing doors 5 can be on the same side of the elevator shaft. However, some of the landing doors 5 could be on an opposite side of the elevator shaft, in which case the elevator car 6 can have elevator car doors 7 on two sides of the elevator car 6.

[0033] Each landing door 5 provides access into the elevator car 6 when the elevator car 6 is at the respective landing. The landing doors 5 of a landing are configured to open substantially at the same time with the respective elevator car doors 7 when the elevator car 6 is located at the landing. During normal operation of the elevator, the elevator car 6 arrives at a landing and actuators arranged in the elevator car 6 open the elevator car doors 7. If the elevator car 6 is provided with elevator car doors 7 on two sides, only some of the elevator car doors 7 may be opened. The elevator car doors 7 and the landing doors 5 are provided with coupling means that are engaged with each other. The landing doors 5 are thus opened at the same time with the elevator car doors 7.

[0034] The landing doors 5 are locked so that the users of the elevator cannot open the landing doors 5, but the landing doors 5 are opened only when the elevator car 6 is located at the landing and the elevator car doors 7 open. However, in certain situations there is a need to be able to open a landing door 5 even if the elevator car 6 is not located at the landing. For instance, if the elevator car

[0035] 6 stops between two landings and the coupling means of the elevator car doors

[0036] 7 and the landing doors 5 are not engaged, the landing doors 5 and the elevator car doors 7 may need to be opened manually to rescue people from the elevator car 6. The elevator shaft may also need to be accessed in order to carry out inspection, service or repair work. When the elevator car 6 is not located at a landing, the landing doors 5 provide access into the elevator shaft, for instance into the pit at the bottom of the elevator shaft or onto the roof of the elevator car 6.

[0037] The locking of the landing doors 5 can be opened by a suitable key or tool, such as a triangular key. If the elevator car 6 is not located at the respective landing, opening of the landing doors 5 does not open the elevator car doors 7.

[0038] To allow safe working in the elevator shaft, the elevator shaft is provided with lighting 4. The lighting 4 of the elevator shaft can comprise one or more lighting units that can be powered by mains current. The lighting 4 of the elevator shaft could also be powered by a battery to allow the lighting to be used even in case of a power blackout.

[0039] In a normal operating state of the elevator, the elevator car 6 is allowed to move only when all the landing doors 5 and the elevator car doors 7 are properly closed. The elevator comprises a safety arrangement for detecting opening and closing of the landing doors 5 and the elevator car doors 7. By monitoring the state of the landing doors 5 and elevator car doors 7, for example moving of the elevator can be prevented in case any of the landing doors 5 or elevator car doors 7 is open. The safety arrangement comprises landing door monitoring means 1 that are configured to monitor the state of the landing doors 5. In the embodiments of the figures, the landing door monitoring means 1 comprise a landing door safety circuit. The landing door safety circuit is provided with a switch 8 or a sensor for each landing door 5 of the elevator shaft to detect opening of a landing door 5. The landing door safety circuit can be implemented using simple electrical switches 8. Each switch 8 can be coupled, for instance, to locking means of the landing door 5. Releasing of the locking means of the landing door 5 can open the switch 8. The switches 8 can be arranged in series in an electric circuit such that opening of any of the landing doors 5 can be detected as an open electric circuit. The safety circuit can thus output an on / off- type signal indicating that at least one of the landing doors 5 is open or all the landing doors 5 are closed. Instead of switches, for example optical sensors could be used to detect opening of a landing door 5.

[0040] The safety arrangement further comprises car door monitoring means 2 that are configured to monitor the state of the elevator car doors 7. The car door monitoring means 2 can comprise a switch 9 or a sensor to detect opening of an elevator car door 7. The car door monitoring means can be implemented, for example, by using an electrical switch that is coupled to locking means of the elevator car door 7. Opening of the elevator car door 7 can open the switch.

[0041] The safety arrangement further comprises control means 3 operatively connected to the landing door monitoring means 1 and to the car door monitoring means 2 to receive information on the state of the landing doors 5 and the elevator car doors 7.

[0042] In the embodiment of the figures, the control means comprise an elevator control unit 3. The elevator control unit 3 can be, for instance, a safety control unit. The elevator control unit 3 monitors the landing door safety circuit. The elevator control unit 3 is further connected to a control unit 10 of the elevator car 6. The control unit 10 of the elevator car 6 monitors the switch 9 of the elevator car doors 7. The control unit 10 of the elevator car 6 is configured to communicate with the elevator control unit 3.

[0043] Based on the monitoring of the state of the landing doors 5 and the state of the elevator car doors 7, the control means 3 are configured to determine whether a shaft access condition is present. A shaft access condition refers here to a situation where the elevator shaft can be accessed via an open landing door 5, i.e. a situation where a landing door 5 is open but the elevator car 6 is not located at the landing having the open landing door 5.

[0044] If a shaft access condition is detected, the control means 3 switch on the shaft lighting 4. The shaft lighting 4 is thus automatically switched on when the elevator shaft potentially can be accessed, and the safety of persons conducting work in the elevator shaft is increased. The safety is also increased in case of unauthorized opening of a landing door 5.

[0045] The control means 3 can be configured to determine that a shaft access condition is present based on the time interval between the opening of the landing door 5 and opening of the elevator car door 7.

[0046] During normal operation of the elevator, the landing doors 5 are opened substantially at the same time as the elevator car doors 7. If only the landing doors 5 open, it is an indication that the elevator car 6 is not positioned at a landing, but the landing doors 5 have been opened manually and a shaft access condition may be present. A shaft access condition can thus be detected by monitoring whether opening of an elevator car door 7 is detected within a predetermined period of time after opening of a landing door 5. The predetermined period of time could be, for instance, less than 2 seconds. That allows switching on the shaft lighting 4 shortly after opening of a landing door 5. As the shaft access condition is detected by detecting not simultaneous opening of a landing door 5 and an elevator car door 7, it is not necessary to determine which landing door 5 has been opened, but simple door monitoring means can be used. This allows implementing the shaft lighting switching functionality mainly by minor changes to elevator software.

[0047] In the embodiment of figure 1 , the elevator control unit 10 controls a relay 11 . If a shaft access condition is detected, the elevator control unit 10 switches the shaft lighting 4 on by means of the relay 11 . The relay 11 may be additionally controllable by one or more manually operable switches or push-buttons 12. The switches or push-buttons 12 can be arranged in the elevator shaft. If the shaft lighting 4 is for some reason not on when the elevator shaft is accessed, the shaft lighting 4 may be switched on manually. If a shaft access condition is detected, normal operation of the elevator is allowed only after resetting the safety circuits. The control means 3 can be configured to switch off the shaft lighting 4 a predetermined time after the elevator has been switched to a normal operating mode. The control functions of the safety arrangement can be implemented in many different ways. For instance, the safety control unit can be a separate control unit or a sub-unit of an elevator controller. The elevator could also be provided with a dedicated shaft lighting control unit receiving information on the state of the landing doors 5 and elevator car doors 7. In the method according to the invention, the state of the landing doors 5 of the elevator shaft is monitored to detect opening of a landing door 5 (step 101 ). The state of the elevator car doors 7 is monitored to detect opening of an elevator car door 7 (step 102). Based on the monitoring of the state of the landing doors 5 and the state of the elevator car doors 5, it is determined whether a shaft access condition is present (step 103). When a shaft access condition has been detected, the shaft lighting 4 is switched on (step 104).

Claims

9Claims:

1. A safety arrangement for an elevator that comprises an elevator shaft having two or more landing doors (5) and an elevator car (6), the safety arrangement comprising- landing door monitoring means (1 ) configured to monitor the state of the landing doors (5) of the elevator shaft to detect opening of a landing door (5),- car door monitoring means (2) configured to monitor the state of elevator car doors (7) to detect opening of an elevator car door (7), and- control means (3) operatively connected to the landing door monitoring means (1 ) and to the car door monitoring means (2) to receive information on the state of the landing doors (5) and the elevator car doors (7), wherein the control means (3) are configured to determine, based on the monitoring of the state of the landing doors (5) and the state of the elevator car doors (7), whether a shaft access condition is present, and to switch on shaft lighting (4) when a shaft access condition is detected.

2. The safety arrangement according to claim 1 , wherein the control means (3) are configured to determine that a shaft access condition is present if opening of an elevator car door (7) is not detected within a predetermined period of time after opening of a landing door (5).

3. The safety arrangement according to claim 2, wherein the predetermined period of time is less than 2 seconds.

4. The safety arrangement according to any of the preceding claims, wherein the control means (3) are configured to switch off the shaft lighting (4) a predetermined time after the elevator has been switched to a normal operating mode.

5. The safety arrangement according to any of the preceding claims, wherein the landing door monitoring means (1 ) comprise a landing door safety circuit that is provided with a switch (8) or a sensor for each landing door (5) of the elevator shaft to detect opening of a landing door (5).

6. The safety arrangement according to any of the preceding claims, wherein the car door monitoring means (2) comprise a switch (9) or a sensor to detect opening of an elevator car door (7).

7. The safety arrangement according to any of the preceding claims, wherein the control means (3) comprise an elevator control unit, such as a safety controller, and / or a dedicated shaft lighting control unit.

8. The safety arrangement according to any of the preceding claims, wherein the car door monitoring means (2) are configured to communicate with the control means (3) via a control unit (10) of the elevator car (6).

9. The safety arrangement according to any of the preceding claims, wherein the control means (3) are configured to control a relay (11 ) for switching on the shaft lighting (4).

10. The safety arrangement according to claim 9, wherein the relay (11 ) is additionally controllable by means of one or more manually operable switches or push-buttons (12).

11. An elevator comprising a safety arrangement according to any of the preceding claims.

12. A computer-implemented method of operating lighting (4) of an elevator shaft, the method comprising the steps of- monitoring the state of the landing doors (5) of the elevator shaft to detect opening of a landing door (5) (101 ),- monitoring the state of the elevator car doors (7) to detect opening of an elevator car door (7) (102),- based on the monitoring of the state of the landing doors (5) and the state of the elevator car doors (5), determining whether a shaft access condition is present (103), and- when a shaft access condition has been detected, switching on the shaft lighting (4) (104).

13. The method of claim 12, wherein the presence of a shaft access condition is identified if opening of an elevator car door (7) is not detected within a predetermined period of time after opening of a landing door (5).1114. The method of claim 13, wherein the predetermined period of time is less than 2 seconds.

15. The method of any of claims 12 to 14, wherein the shaft lighting (4) is switched off a predetermined time after the elevator has been switched to a normal operating mode.

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