Elevator with a safety arrangement and method for creating a safe working space in the upper part of the elevator shaft

Abstract

The invention relates to methods and arrangements for creating a safe working space in the upper part of an elevator shaft. A position of an elevator car in the elevator shaft in relation to a plurality of safety levels in the elevator shaft may be monitored, where each safety level is associated with a separate clearance of the elevator car from a ceiling of the elevator shaft. The elevator may be controlled to create a safety space zone at the upper part of the elevator shaft. The controlling may include progressively activating separate braking systems in response to the elevator car progressively moving upwards through separate triggering limits of separate clearances, to progressively strengthen an arresting of upwards movement of the elevator car through the elevator shaft.

Claims

1. An elevator with a safety arrangement for creating a safe working space in an upper part of an elevator shaft, the elevator comprising: an elevator car configured to move in the elevator shaft along a plurality of guide rails; a counterweight connected to the elevator car; an instance of hoisting machinery in the upper part of the elevator shaft, the instance of hoisting machinery including a plurality of operating brakes; and an elevator control system configured to monitor a position of the elevator car in the elevator shaft in relation to a plurality of safety levels in the elevator shaft, each safety level associated with a separate clearance of the elevator car from a ceiling of the elevator shaft, and control the elevator, based on the elevator being in an inspection mode or maintenance mode, to create a safety space zone at the upper part of the elevator shaft, the controlling including performing progressively strengthening safety operations in response to the elevator car progressively moving upwards through separate triggering limits of separate clearances associated with separate safety levels of the plurality of safety levels, the performing progressively strengthening safety operations including performing a first safety operation to activate an alarm device to prompt manual stopping of the elevator car in response to a determination that the elevator car has moved upwards through a first triggering limit at a lower edge of a first clearance of the elevator car from the ceiling of the elevator shaft, the first clearance associated with a first safety level of the plurality of safety levels, and performing a second safety operation to activate a braking system that is configured to arrest upwards movement of the elevator car through the elevator shaft in response to a determination that the elevator car has moved upwards through a second triggering limit at a lower edge of a second clearance of the elevator car from the ceiling of the elevator shaft, the second clearance associated with a second safety level of the plurality of safety levels, wherein a magnitude of the first clearance is greater than a magnitude of the second clearance.

2. The elevator according to claim 1, wherein the plurality of safety levels includes the first safety level, the second safety level, and a third safety level, the third safety level is associated with a third clearance of the elevator car from the ceiling of the elevator shaft, a third triggering limit of the third clearance being at a lower edge of the third clearance, and the magnitude of the second clearance is greater than a magnitude of the third clearance.

3. The elevator according to claim 2, wherein each clearance of the elevator car from the ceiling of the elevator shaft is associated with a separate minimum distance between a roof of the elevator car and the ceiling of the elevator shaft.

4. The elevator according to claim 1, further comprising: two independent sensor systems, each independent sensor system configured to generate sensor data indicating an actual position of the elevator car with respect to the ceiling of the elevator shaft, wherein the elevator control system is configured to monitor the position of the elevator car in the elevator shaft in relation to the plurality of safety levels in the elevator shaft based on processing the sensor data generated by the two independent sensor systems.

5. The elevator according to claim 1, wherein the performing the second safety operation to activate the braking system includes activating both a safety circuit of the elevator and the plurality of operating brakes of the instance of hoisting machinery in response to the determination that the elevator car has moved upwards through the second triggering limit at the lower edge of the second clearance.

6. The elevator according to claim 2, wherein the performing progressively strengthening safety operations includes performing a third safety operation to activate a safety gear system of the elevator in response to a determination that the elevator car has moved upwards through the third triggering limit at the lower edge of the third clearance.

7. A method for creating a safe working space in an upper part of an elevator shaft of an elevator, the elevator further including an elevator car configured to move in the elevator shaft along a plurality of guide rails, the method comprising: monitoring a position of the elevator car in the elevator shaft in relation to a plurality of safety levels in the elevator shaft, each safety level associated with a separate clearance of the elevator car from a ceiling of the elevator shaft; and controlling the elevator, based on the elevator being in an inspection mode or maintenance mode, to create a safety space zone at the upper part of the elevator shaft, the controlling including performing progressively strengthening safety operations in response to the elevator car progressively moving upwards through separate triggering limits of separate clearances associated with separate safety levels of the plurality of safety levels, the performing progressively strengthening safety operations including performing a first safety operation to activate an alarm device to prompt manual stopping of the elevator car in response to a determination that the elevator car has moved upwards through a first triggering limit at a lower edge of a first clearance of the elevator car from the ceiling of the elevator shaft, the first clearance associated with a first safety level of the plurality of safety levels, and performing a second safety operation to activate a braking system that is configured to arrest upwards movement of the elevator car through the elevator shaft in response to a determination that the elevator car has moved upwards through a second triggering limit at a lower edge of a second clearance of the elevator car from the ceiling of the elevator shaft, the second clearance associated with a second safety level of the plurality of safety levels, wherein a magnitude of the first clearance is greater than a magnitude of the second clearance.

8. The method according to claim 7, wherein the plurality of safety levels includes the first safety level, the second safety level, and a third safety level, the third safety level is associated with a third clearance of the elevator car from the ceiling of the elevator shaft, a third triggering limit of the third clearance being at a lower edge of the third clearance, and the magnitude of the second clearance is greater than a magnitude of the third clearance.

9. The method according to claim 7, wherein the controlling the elevator to create the safety space zone is in response to a determination that an entry triggering system of the elevator is triggered in response to an individual entering the elevator shaft, and the monitoring includes processing sensor data generated by two independent position sensor systems to determine an actual position of the elevator car with respect to the ceiling of the elevator shaft.

10. The method according to claim 8, wherein the monitoring continuously monitors movement of the elevator car and the position of the elevator car based on continuously processing sensor data generated by two independent position sensor systems, and the performing progressively strengthening safety operations includes performing the second safety operation to activate a safety circuit of the elevator and activating operation brakes of elevator machinery of the elevator to stop the elevator car in response to the determination that the elevator car has moved upwards through the second triggering limit at the lower edge of the second clearance, and performing a third safety operation to activate a safety gear system of the elevator to stop the elevator car and to lock the elevator car into the guide rails in response to a determination that the elevator car has moved upwards through the third triggering limit at the lower edge of the third clearance.

Description

(1) In the following, the invention will be described in detail by the aid of example embodiments by referring to the attached simplified and diagrammatic drawings, wherein

(2) FIG. 1 presents in a simplified and diagrammatic side view a part of the building where the back wall of the elevator shaft is removed, and an elevator in the elevator shaft, in which elevator the arrangement and method according to the invention can be used,

(3) FIG. 2 presents in a simplified and diagrammatic side view the upper part of the elevator shaft in the building according to FIG. 1,

(4) FIG. 3 presents in a simplified and diagrammatic side view another solution according to the invention,

(5) FIG. 4 presents in a simplified and diagrammatic block diagram mains parts of the safety arrangement according to the invention, and

(6) FIG. 5 presents in a simplified and diagrammatic flow chart the method according to the invention.

(7) The main idea of the invention is to create a reliable and adequate safety space with pre-defined clearances CL1, CL2 CL3 at the upper part of an elevator shaft between the roof 5a of the elevator car 5 and the ceiling 2a of the elevator shaft 4. The safety space is created by progressively strengthening safety actions or operations based on the information about the need of the safety working space by using elevator car position data and either mechanical, electrical or logical means or any of their combinations.

(8) FIG. 1 presents in a simplified and diagrammatic side view a part of the building 1 where the back wall of the elevator shaft 4 is removed, and an elevator in the elevator shaft 4, in which elevator the arrangement and method according to the invention can be used. The building 1 has a roof 2 just above the elevator shaft 4 and four floors 3 served by the elevator.

(9) The elevator is a so-called Machine-Room-Less (MRL) elevator where the elevator machinery 8 with its operating brakes 8b and traction sheave 8c is in the elevator shaft 4 or in an appropriate space adjacent to the elevator shaft 4, and in the upper area of the elevator shaft, advantageously just below the ceiling 2a of the elevator shaft 4. In addition the elevator comprises among other things an elevator car 5 that is arranged to run up and down in the elevator shaft 4 along guide rails 7, and a counterweight 6 or balance weight that is also arranged to run up and down in the elevator shaft 4 along its guide rails which are not presented in FIG. 1 for the sake of clarity. The elevator car 5 and the counterweight 6 are connected to each other with elevator ropes or hoisting ropes that also are not presented in FIG. 1 for the sake of clarity. The cross section of the hoisting ropes can be round or as a flat rectangle. The elevator car 5 is also equipped with safety gear system 5c that is arranged to stop the movement of the elevator car 5 and to lock the elevator car 5 into the guide rails 7 when needed. If the safety gear system 5c used in this arrangement is in the elevator car 5 it is a bi-directional system. Whereas, if the safety gear system is installed in the counterweight 6, it can be unidirectional.

(10) Each floor has a landing door 9 that is presented in FIG. 1 seen from the direction of the elevator shaft 4. In addition the elevator comprises at least an operating system, a control system 8a, an electrical system, a variety of sensors arrangements and a safety system.

(11) FIG. 2 presents in a simplified and diagrammatic side view the upper part of the elevator shaft 4 in the building 1 according to FIG. 1. Also in this figure the back wall of the elevator shaft 4 is removed and the elevator shaft 4 is seen from its backside.

(12) The safety arrangement according to the invention comprises two independent position sensor systems 11 and 12 to monitor the actual position of the elevator car 5 with respect to the ceiling 2a of the elevator shaft 4. The first position sensor system 11 comprises, for instance a laser measurement sensor 11a installed in the ceiling 2a of the elevator shaft 4. The laser measurement sensor 11a is arranged to measure the actual distance between the roof 5a of the elevator car 5 and the ceiling 2a of the elevator shaft 4.

(13) The second position sensor system 12 comprises, for instance a series of inductive position measurement sensors 12a installed in the inner wall of the elevator shaft 4, and an appropriate counter sensor installed in the wall of the elevator car 5 so that when the elevator car is moving the counter sensor passes one by one each inductive position measurement sensor 12a whose location is known and thus the position of the elevator car and at the same time the distance between the roof 5a of the elevator car 5 and the ceiling 2a of the elevator shaft 4 can be determined.

(14) The first and second position sensor systems 11, 12 can also comprise other kinds of distance or position measuring sensors, such as other optical or electrical sensors than laser sensors, or magnetic sensors or mechanical position sensors. The sensors of the position sensor systems 11, 12 are connected to the elevator operation system, to the elevator control system 8a and to the elevator safety system.

(15) The elevator safety system according to the invention comprises three levels of safety operations in order to create an artificial pre-defined safety space zone 10 with an adequate clearance at the upper part of the elevator shaft 4 when the elevator is in an inspection or maintenance mode, later only the term inspection mode is used. Hereinafter the three levels of safety operations are called in a shorter way safety levels I, II and III. The safety operations here comprise at least one or more of the following operations: producing an alarm to stop the upwards-moving elevator car 5, switching off the electrical safety circuit, activating the operating brakes 8b of the elevator, activating the safety gear system 5c of the elevator.

(16) The adequate clearance is the pre-defined distance CL1, CL2, CL3 between the roof 5a of the elevator car 5 and the ceiling 2a of the elevator shaft 4. In the safety level I the clearance CL1 is for example 4.0 m, in the safety level II the clearance CL2 is for example 3.0 m, and in the safety level III the clearance CL3 is for example 2.5 m. These measures can be varied depending of the elevator, but always the safety level I clearance CL1 is the longest distance and the safety level III clearance CL3 is the shortest distance. In the other words, the lower limit of the safety level I clearance CL1 or the first triggering limit L1 is at the lowest height, the lower limit of the safety level II clearance CL2 or the second triggering limit L2 is in the middle height and the lower limit of the safety level III clearance CL3 or the third triggering limit L3 is at the highest height.

(17) The elevator safety system according to the invention comprises also an entry triggering system 13 that is arranged to inform the elevator when someone enters into the elevator shaft 4 outside the elevator car 5. In that case usually someone steps inside the elevator shaft 4 through one of the landing doors 9. FIG. 2 presents an entry triggering system 13 with a trigger sensor 13a inside the elevator shaft 4 close to each landing door 9. When the landing door 9 is opened manually, for example from a floor 3 the trigger sensor 13a is arranged to send a signal to the elevator safety system which is further arranged to set the elevator to the inspection mode.

(18) FIG. 3 presents another entry triggering system 13 that is arranged to inform the elevator when someone steps onto the roof 5a of the elevator car 5. This entry triggering system 13 comprises a trigger sensor 13b that is installed between a moving plate 14 and the roof 5a of the elevator car 5. The moving plate 14 is installed to move up and down on the roof 5a of the elevator car 5 and is supported by springs 15 so that the cap between the moving plate 14 and the roof 5a of the elevator car 5 is such that the trigger sensor 13b remains non-activated. When someone steps onto the moving plate 14 the plate 14 moves downwards towards the spring force and at the same time activates the trigger sensor 13b. In that case the trigger sensor 13b is arranged to send a signal to the elevator safety system, which is further arranged to set the elevator to the inspection mode. The activation of the inspection mode can also be arranged so that there is a button for the activation of the inspection mode on the roof 5a of the elevator car 5, and when the trigger sensor 13b has been activated by the load of a person on the plate 14 the elevator car 5 does not move before the button for the activation of the inspection mode is pressed.

(19) In the inspection mode the elevator car 5 can be driven manually using for instance an appropriate inspection drive controller on the roof 5a of the elevator car 5. The entry triggering system 13 also comprises an appropriate electronic logic control system that is arranged to initiate the safety action when the landing door 9 is opened or someone has stepped onto the moving plate 14.

(20) FIG. 4 presents in a simplified and diagrammatic block diagram main parts of the safety arrangement according to the invention. The elevator comprises a variety of sensors, such as the two independent position sensor systems 11 and 12 with their position sensors 11a and 12a in the elevator shaft 4, and the entry triggering system 13 with its sensors 13a or 13b that also are in the elevator shaft 4, and other appropriate sensors in appropriate places. All the sensors in the safety system are connected to the elevator control system 8a through a receiving means 16 that is arranged to receive the data from the sensor systems 11, 12, 13, and to forward the received data further to a data processing means of the elevator control system 8a. The data processing means 17 is arranged to process the data received and to activate an activating means 17 for the safety level I if the monitored position of the elevator car 5 crosses the first triggering limit L1 or the lower limit of the safety level I clearance CL1, and to activate an activating means 18 for the safety level II if the position of the elevator car 5 crosses the second triggering limit L2 or the lower limit of the safety level II clearance CL2, and to activate an activating means 19 for the safety level III if the position of the elevator car 5 crosses the third triggering limit L3 or the lower limit of the safety level III clearance CL3. The triggering limit L1, L2, L3 or the lower limit of each clearance CL1, CL2 or CL3 is the same as the maximum height where the elevator car 5 can be in each safety level I, II or III. Crossing the triggering limit L1, L2 or L3 means that the elevator car 5 is aiming to drive higher than is allowed on each safety level I, II or III.

(21) The activating means 17 for the safety level I is connected, for example to activate an alarm device 5b that is situated for instance on the roof 5a of the elevator car 5. The alarm device 5b can be for instance a buzzer, a blinking light a loudspeaker, or another appropriate device. It can also be in another place in the elevator shaft 4 than on the roof 5a of the elevator car 5. The purpose of the alarm is to inform the person on the roof 5a of the elevator car 5 that the elevator car 5 is driving too high and has to be stopped by the person.

(22) The activating means 18 for the safety level II is connected, for example to activate the electrical safety circuit of the elevator and to activate the operating brakes 8b of the elevator machinery 8. The activating means 18 for the safety level II can also be connected to another kind of a braking system to stop the upwards movement of the elevator car 5.

(23) Whereas the activating means 19 for the safety level III is connected, for example to activate the safety gear system 5c of the elevator to stop the upwards movement of the elevator car 5 and to lock the elevator car 5 into the guide rails 7. In the safety level III the elevator car 5 is arranged to keep firmly in its place so that at least the minimum required safety distance between the roof 5a of the elevator car 5 and the ceiling 2a of the elevator shaft 4 is maintained in all conditions.

(24) The safety levels I, II and III and their functions are arranged to be used only when the elevator is in the inspection mode. The safety level I is activated automatically when the elevator is set to the inspection mode. In that case when the elevator car 5 is driven upwards with the inspection drive and the position of the elevator car 5 is continuously measured by the two independent position sensor systems 11 and 12, the elevator control system 8a is arranged to monitor the movement of the elevator car 5, and to stop the movement of the elevator car 5 in a progressively strengthening way in the three safety levels I, II and III if the elevator car 5 is aiming to drive too high in the elevator shaft 4 when someone is on the roof 5a of the elevator car 5. The progressively strengthening way mentioned above means that the upwards movement of the elevator car 5 is stopped, when the elevator is in the inspection or maintenance mode, with actions which are arranged to become more and more effective and definitive safety level by safety level. In that case there is only a warning message on the first safety level I, the activation of the safety circuit and the operation brakes 8b of the elevator on the second safety level II, and the activation of the safety gear system 5c on the third safety level III.

(25) FIG. 5 presents in a simplified and diagrammatic flow chart a method according to the invention. Only main steps of the method are presented in FIG. 5. The method according to the invention for creating a safe working space in the upper part of the elevator shaft 4 has at least the steps as follows:

(26) an artificial safety space zone 10 with three safety levels I, II and III is created at the upper end of the elevator shaft 4 and the minimum safety clearances CL1, CL2 and CL3 for each safety level I, II and III are defined with two independent position sensor systems 11, 12 to monitor the crossing of triggering limits L1, L2, L3 or the lower limits of the safety clearances CL1, CL2 and CL3,

(27) an entry into the elevator shaft 4 is monitored with the sensors 13a of the entry triggering system 13, or stepping onto the roof 5a of the elevator car 5 monitored with the sensors 13b of the entry triggering system 13,

(28) if someone is detected by the entry triggering system 13 of entering into the elevator shaft 4 through a landing door 9 or detected of stepping onto the roof 5a of the elevator car 5, the detection information is sent to the elevator control system 8a and the elevator is set to the inspection mode where the elevator car 5 can be driven using an inspection drive controller on the roof 5a of the elevator car 5, or the elevator car 5 is kept firmly in its place without a possibility to drive the car 5 until the appropriate inspection mode button on the roof 5a of the elevator car 5 is pressed,

(29) The inspection mode is now on and the elevator car 5 can be driven using the inspection drive controller on the roof 5a of the elevator car 5.

(30) When the elevator car 5 is driven upwards using the inspection drive controller on the roof 5a of the elevator car 5 the steps of the method according to the invention continues as follows:

(31) the movement and the position of the elevator car 5 is monitored by the two independent position sensor systems 11 and 12,

(32) if the monitored position of the elevator car 5 crosses the first triggering limit L1, the crossing is detected by the position sensor systems 11 and 12, and the detected information is sent to the elevator control system 8a, and an alarm is activated through an appropriate alarm device 5b. In this case the upwards movement of the elevator car 5 can be manually stopped by the person on the roof 5a of the elevator car 5,

(33) the movement and the position of the elevator car 5 is continuously monitored by the two independent position sensor systems 11 and 12,

(34) if for some reason the alarm did not work or alarm is ignored, and the monitored position of the elevator car 5 crosses the second triggering limit L2, the detected information is sent to the elevator control system 8a, and the electrical safety circuit of the elevator is activated to switch off the power of the elevator motor, and the operating brakes 8b of the elevator machinery 8 are activated to stop the upwards movement of the elevator car 5,

(35) the movement and the position of the elevator car 5 is continuously monitored by the two independent position sensor systems 11 and 12,

(36) if the car 5 still tends to move upwards, and the monitored position of the elevator car 5 crosses the third triggering limit L3, the detected information is sent to the elevator control system 8a, and the safety gear system 5c of the elevator is activated to stop the upwards movement of the elevator car 5 and to lock the elevator car 5 into the guide rails 7,

(37) in the safety level III the elevator car 5 is kept firmly in its place so that at least the minimum required safety distance between the roof 5a of the elevator car 5 and the ceiling 2a of the elevator shaft 4 is maintained in all conditions.

(38) It is essential to the arrangement and method according to the invention that when someone has entered into the elevator shaft 4 through a landing door 9, or—in certain solutions—when someone has stepped onto the roof 5a of the elevator car 5, the attendance is detected and informed to the elevator control system 8a that is arranged to activate the pre-defined safety space zone 10 at the upper part of the elevator shaft 4 using a number of different safety levels, for instance, three safety levels I, II and III where the efficiency to stop the movement of the elevator car 5 increases from the safety level I to the safety level III.

(39) It is obvious to the person skilled in the art that the invention is not restricted to the examples described above but that it may be varied within the scope of the claims presented below. Thus, for instance the order of the method steps may differ from the order presented in the claims, or method steps may be more or less than presented in the claims.

(40) It is also obvious to the person skilled in the art that the sensor and monitoring systems can be different from what is presented above.