Elevator safety device

Abstract

An elevator safety device (16) for monitoring landing doors (10) of an elevator system (2) is provided. The elevator system (2) includes a landing door sensor (14) arranged to detect the state of the landing door (10). The elevator safety device (16) includes a power supply (20) arranged to power the landing door sensor (14) independently of the power supply (19) of the elevator system (2), and a memory (22) arranged to record the state of the landing door (10) detected by the landing door sensor (14) when the landing door sensor (14) is powered by the power supply (20).

Description

Technical Field

[0001] This disclosure relates to elevator safety devices. Background Technology

[0002] Elevator systems are typically characterized by one or more elevator cars operating in a shaft to transport passengers or goods between floors of a building. Landing doors (sometimes called shaft doors) at each floor provide access to the elevator cars. Landing doors also provide access to the shaft itself, for example, for maintenance purposes. For instance, the lowest landing door might be used to access the pit area at the bottom of the shaft.

[0003] Generally, elevator systems continuously monitor landing doors to detect their opening or closing (e.g., using landing door switches). If a landing door is detected opening unexpectedly, the elevator system can take appropriate safety actions. For example, if the lowest landing door is detected opening without any adjacent elevator car, the system can assume that a technician is entering the pit area and force the elevator car into inspection mode operation. This can limit the car's operating speed and / or restrict movement to specific areas in the hoistway to ensure the technician can work safely in the pit area. Upon leaving the pit area, the technician then manually resets the safety system to allow a return to normal operating mode.

[0004] However, if the elevator system experiences a power outage (e.g., during an unplanned power outage or a planned shutdown), it is impossible to monitor the landing doors. Therefore, when power is restored, the elevator system must assume that the shaft was entered while monitoring was unavailable and take corresponding safety actions (e.g., activating a check mode). This must then be manually reset to allow normal elevator operation. This can be inconvenient if the shaft was not actually entered during the power outage period. An improved approach may be desirable. Summary of the Invention

[0005] According to a first aspect of this disclosure, an elevator safety device is provided for monitoring landing doors in an elevator system, the elevator system including landing door sensors arranged to detect the state of the landing doors, the elevator safety device comprising: The power supply, arranged independently of the elevator system's power supply, powers the landing door sensors; and A memory, arranged to record the state of the landing door detected by the landing door sensor when the landing door sensor is powered by a power source.

[0006] This disclosure extends to an elevator system comprising: Station doors; Terminal door sensors are arranged to detect the status of the terminal doors; The power supply is arranged to power the elevator system. Elevator controller, which is arranged to control the elevator system; and As disclosed in this article, the elevator safety device is arranged to monitor the landing doors.

[0007] Those skilled in the art will recognize that elevator safety devices can provide improved landing door monitoring because the landing door sensors can be powered when the elevator system's power supply is unavailable. For example, this allows monitoring of the landing door status during a power outage and reading information about that status from memory once the outage ends. For instance, if the memory indicates that no landing door was opened during the power outage, the elevator system can infer that no one entered the shaft during the outage and can immediately resume full operation without human intervention.

[0008] Furthermore, elevator safety devices can be easily retrofitted into existing elevator systems because they can utilize existing landing door sensors. For example, the elevator safety device can be simply connected in parallel with the existing landing door sensing circuit to the landing door sensor.

[0009] Elevator safety devices can be configured to power the landing door sensors using a power source when the elevator system's power supply is interrupted, such as during a power outage or planned shutdown. This ensures that landing door monitoring continues even when the elevator system's power supply is unavailable.

[0010] Elevator safety devices can be configured to initiate power supply to the landing door sensors in response to a power outage in the elevator system (e.g., in response to a signal indicating a power outage). Elevator safety devices can also be configured to monitor the power supply to the elevator system. Furthermore, elevator safety devices can be configured to automatically supply power to the landing door sensors when a power outage in the elevator system is detected.

[0011] Elevator safety devices can be arranged to disconnect the landing door sensor from the power supply when the elevator system's power supply is active (e.g., when the power supply is reactivated after an interruption). Disconnecting the power supply from the landing door sensor when the elevator system's power supply is active reduces redundant use of energy from the power supply and mitigates interference with existing landing door sensing circuitry. In one set of examples, the elevator safety device includes a switching assembly (e.g., a relay) arranged to controllably connect the power supply to the landing door sensor.

[0012] The power supply can be the main power supply for the elevator system, for example, it is used to power the movement of one or more elevator cars between intermediate floors in the shaft.

[0013] The power supply can be configured to power only the landing door sensors and the elevator safety devices themselves. This allows for the use of relatively low-cost and small-sized power supplies. In one set of examples, the power supply includes batteries, capacitors, or supercapacitors. The power supply can have an energy capacity of less than 5Wh, less than 1Wh, or less than 0.5Wh. The elevator safety devices can be configured to use the elevator system's power supply to recharge the power supply.

[0014] Elevator safety devices can be arranged to communicate with the elevator controller of the elevator system, for example, to report the recorded status of the landing doors to the elevator controller. The elevator safety devices can also be arranged to report the status of the landing doors, recorded in memory, to the elevator controller after (e.g., immediately following) a power outage in the elevator system.

[0015] The elevator controller can be configured to control the elevator system based on the state of the landing doors recorded in a memory. For example, the elevator controller can be configured to perform a safety action (e.g., activate a check mode) if the memory indicates that the landing door is open. The elevator controller can be configured to activate a normal operating mode if the memory indicates that the landing door is not open.

[0016] In one set of examples, the elevator safety device includes a microcontroller. The microcontroller may be arranged to communicate with the elevator controller of the elevator system. The microcontroller may be arranged to read from and / or reset the memory. The microcontroller may be arranged to act as an interface between the memory and the elevator controller. The microcontroller may be arranged to control the connection of power supply to the landing door sensor. For example, in an example characterized by a switching assembly arranged to controllably connect power supply to the landing door sensor, the microcontroller may be arranged to control the switching assembly. In some examples, one or more of these functions may be performed directly by the elevator controller. For example, the memory may be arranged to be directly read from and / or reset by the elevator controller. However, using a microcontroller as part of the elevator safety device (e.g., located physically away from the elevator controller) may be advantageous to simplify installation.

[0017] The memory can be very small. For example, the memory may include 32 bits or less (e.g., 16 bits or 8 bits) of data storage. In some instances, the memory is arranged to record a single data point, such as a single data point indicating whether the landing door has been open at any point in time since the memory was last reset. The memory may even consist of a 1-bit data storage element (i.e., a latch) arranged to change state if the landing door sensor detects an open landing door. Small memories may be low-cost and easy to implement, while still recording enough information to allow the elevator system to determine whether the landing door has been open at any point in time during a power outage. While such small memories may not record detailed information about landing door activity, this may not be necessary to avoid many unnecessary manual resets (i.e., when there is no landing door activity during an outage). Of course, in some instances, the memory is arranged to record additional information, such as a log recording changes in the state of the landing doors (e.g., a timestamped log of landing door events).

[0018] The memory may include any computer memory suitable for recording the state of the landing doors. Preferably, the memory includes non-volatile memory, such as EEPROM or flash memory. The memory may include data buffers, such as first-in-first-out (FIFO) memory. The memory may include hardware registers. The elevator safety device (e.g., the microcontroller of the elevator safety device) may be arranged to erase or reset the memory. For example, the elevator safety device may be arranged to erase or reset the memory when power is first supplied to the landing door sensors (e.g., when the power supply to the elevator system is interrupted). In some instances, the elevator safety device may be arranged such that the memory can be directly erased or reset by the elevator controller.

[0019] The landing door sensor may include any landing door sensor known in the art. In one set of examples, the landing door sensor includes a switch that establishes an electrical connection between a first electrical terminal and a second electrical terminal when the landing door is closed, and that disconnects the electrical connection when the door is opened (or vice versa). The landing door sensor may include a contact switch (e.g., a pair of electrical contacts coupled to a corresponding portion of the landing door and arranged to enter / de-enter electrical contact as the door is opened / closed). Alternatively, the landing door sensor may include a non-contact switch such as a reed switch.

[0020] The power supply can be arranged in series with the landing door sensor. For example, in an instance where the landing door sensor includes a switch, the power supply can be arranged in series with the switch (e.g., connected to the first terminal of the switch). The elevator safety device can be arranged to supply current to the switch (e.g., by connecting the switch to the power supply). The elevator safety device can be arranged to supply direct current (DC) or alternating current (AC) to the switch. For example, in one set of examples, the elevator safety device can be arranged to apply a fixed (for DC) or variable (for AC) voltage to the first terminal of the switch and monitor the voltage at the second terminal of the switch.

[0021] Elevator safety devices may include power converters (e.g., voltage regulators, rectifiers, inverters, or switch-mode power supplies) arranged to generate a fixed or varying voltage from a power source. Elevator safety devices may include a sensing circuit portion arranged to sense the voltage at a second terminal of a switch.

[0022] The presence or absence of a fixed or varying voltage at the second terminal indicates the state of the switch and thus the state of the landing door. Therefore, the elevator safety device can simply infer the state of the landing door by monitoring the second terminal (and record it in memory). Furthermore, in some instances where the elevator safety device supplies a varying voltage (AC) to the first terminal, the voltage at the second terminal can be monitored and analyzed to determine the state of the landing door and / or additional information about the elevator safety device or landing door sensors. For example, the type of AC voltage generated at the second terminal can be analyzed to detect not only the state of the switch but also faults or problems in the switch or associated circuitry (such as connecting cables).

[0023] The memory can be arranged in series with the landing door sensor. For example, in an example where the landing door sensor includes a switch, the memory can be arranged in series with the switch (e.g., connected to the second terminal of the switch). This allows for a particularly simple implementation of the elevator safety circuit. For example, the elevator safety device can be arranged to supply a DC voltage to the first terminal of the switch, such that the DC voltage on the second terminal indicates the state of the landing door. In this example, the DC voltage on the second terminal can be used as direct data input to the memory, allowing the memory to record the state of the landing door (e.g., eliminating the need for a sensing circuit portion).

[0024] Landing door sensors may include dedicated landing door sensors (i.e., landing door sensors primarily or exclusively used by elevator safety devices). Landing door sensors may be part of the elevator safety device. However, in some instances, landing door sensors include existing landing door sensors in the elevator system; that is, the elevator safety device is arranged to connect to existing landing door sensors.

[0025] In one set of examples, the elevator controller is arranged to receive information from the landing door sensor independently of the elevator safety device. For instance, the elevator system may include landing door sensing circuitry arranged to connect the landing door sensor to the elevator controller independently of the elevator safety device. The landing door sensing circuitry may be connected in parallel with the landing door sensor to the elevator safety device.

[0026] The elevator controller can be arranged to control the elevator system based on information received from the landing door sensors independently of elevator safety devices (e.g., the state of the landing doors detected by the landing door sensors). For example, the elevator controller can be arranged to perform a safety action (e.g., activate a check mode) if information received from the landing door sensors independently of elevator safety devices indicates that the landing door has opened unexpectedly. The elevator system can be arranged to use the elevator system's power supply to power the landing door sensors.

[0027] Elevator systems typically include several landing doors (e.g., for access to multiple floors in a building). Therefore, an elevator system may include multiple landing doors. The elevator system may also include multiple corresponding landing door sensors, each arranged to detect the status of its respective landing door.

[0028] Elevator safety devices can be arranged to monitor individual landing doors. An elevator safety device may include a single physical device located adjacent to (e.g., less than 5 m or less than 2 m away) the landing door it monitors. Multiple elevator safety devices may be provided for corresponding multiple landing doors in an elevator system. The elevator system may include multiple elevator safety devices as disclosed herein, wherein the power supply of each elevator safety device is arranged to power the corresponding landing door sensor independently of the elevator system's power supply, and the memory of each elevator safety device is arranged to record the state of the landing door detected by the corresponding landing door sensor when the landing door sensor is powered. Providing elevator safety devices for multiple landing doors in an elevator system (e.g., for each landing door in the elevator system) allows for the collection of information about the state of all landing doors during a power outage of the elevator system.

[0029] In some instances, elevator safety devices may be arranged to monitor multiple landing doors. For example, a power supply may be arranged to power multiple landing door sensors independently of the elevator system's power supply, with each landing door sensor arranged to detect the state of a corresponding landing door. A memory may be arranged to record the states of some or all of the multiple landing doors detected by the landing door sensors when the sensors are powered. In some instances, the elevator safety device includes multiple memories arranged to record the corresponding states of multiple landing doors.

[0030] More generally, an elevator system may include a first elevator safety device arranged to monitor a first set of landing doors and a second elevator safety device arranged to monitor a second set of landing doors. The first and second sets may be of different sizes and may each contain one or more landing doors. For example, the first elevator safety device may be arranged to monitor only the lowest landing door (e.g., for access to the pit area), and the second elevator safety device may be arranged to monitor some or all of the other landing doors.

[0031] Elevator safety devices may include a single physical device, such as having power and / or data terminals for connecting the elevator safety device to landing door sensors and / or the elevator system. Elevator safety devices may be integrated with other elevator circuits, such as other door or pit safety devices. For example, components constituting the elevator safety device may be included on a single circuit board along with components for other functions. Elevator safety devices may be small enough to be installed within existing landing door sensor circuitry. For example, an elevator safety device (or a larger device, such as a circuit board including components constituting the elevator safety device) may have a maximum dimension of less than 0.5m, less than 0.1m, or less than 0.05m. An elevator safety device may have a maximum dimension of less than 0.25m. 2 Less than 0.01m 2 or less than 0.0025m 2 The floor space occupied by elevator safety devices is less than 0.125m. 3 Less than 0.001m 3 or less than 0.000125m 3 The volume.

[0032] Where appropriate, features of any aspect or instance described herein may be applied to any other aspect or instance described herein. In referring to different instances, it should be understood that these are not necessarily different, but rather may overlap. Attached Figure Description

[0033] One or more non-limiting examples will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of an elevator system according to an example of this disclosure; and Figure 2 yes Figure 1 The diagram shows a portion of the elevator safety system of the elevator system shown. Detailed Implementation

[0034] like Figure 1 As shown, elevator system 2 includes elevator car 4, which travels in shaft 6 to transport passengers and / or goods between floors 8 in a building. Shaft 6 includes a pit area 7 located below the lowest floor 8.

[0035] Each floor 8 is characterized by a floor door 10, which allows entry into the elevator car 4 when the elevator car 4 is adjacent to the floor 8, and allows entry into the hoistway 6 itself when the elevator car 4 is not adjacent to the floor 8.

[0036] Elevator system 2 includes elevator safety system 12, which includes multiple landing door switches 14, multiple elevator safety devices 16, and elevator controller 18. Each landing door switch 14 detects whether the corresponding landing door 10 is open or closed. Elevator controller 18 is connected to landing door switch 14 via landing door sensing circuit 15. Elevator system 2 is powered by power supply 19.

[0037] Figure 2 A portion of the elevator safety system 12 is shown in more detail. Figure 2 One of the landing door switches 14, elevator safety device 16, and elevator controller 18 are shown. The landing door switch 14 establishes an electrical connection between the first electrical terminal 28 and the second electrical terminal 30 when the landing door 10 is closed, and disconnects the electrical connection when the landing door 10 is open.

[0038] The elevator safety device 16 includes a battery 20, a non-volatile memory 22, and a microcontroller 24. The battery 20 is connected to the first terminal 28 of the landing door switch 14 via a switch 26. The non-volatile memory 22 is connected to the second terminal 30 of the landing door switch 14. The microcontroller 24 is powered by the battery 20 and communicates with the elevator controller 18.

[0039] During normal operation, the elevator car 4 moves between floors 8 to carry passengers and / or goods. Sometimes it may be necessary to enter the shaft 6. For example, an elevator technician may want to enter the pit area 7 of the shaft 6 to perform maintenance operations. To do this, the technician opens the lowest floor door 10 and climbs into the pit area 7 while the elevator car 4 is elsewhere.

[0040] The elevator controller 18 detects that the lowest floor door 10 is open based on a signal from the lowest floor door switch 14 (via the floor door sensing circuit 15). Since the elevator car 4 is not adjacent to this floor door 10, the elevator controller 18 activates a check mode that limits the operating speed of the elevator car 4 and prevents it from moving into the pit area 7. This ensures that technicians can safely perform maintenance operations in the pit area 7. When technicians leave the pit area 7, they manually indicate to the elevator controller 18 that they have left the hoistway 6 and resume normal operation.

[0041] If the elevator system 2 loses power (e.g., due to an unplanned power outage or interruption), the elevator controller 18 can no longer actively monitor the status of the landing door 10 via the landing door sensing circuit 15. Therefore, the microcontroller 24 monitors the power supply 19 (e.g., via the elevator controller 18), and when the microcontroller 24 detects an interruption in the power supply 19, it resets the memory 22 and closes the switch 26 to connect the battery 20 to the landing door switch 14. A small DC current flows through the landing door switch 14.

[0042] If the landing door switch 14 is open (i.e., if the corresponding landing door 10 is open) and the power supply 19 is interrupted (i.e., when the battery 20 is connected to power the landing door switch 14), a DC interruption occurs through switch 14. This causes the non-volatile memory 22 to record that the landing door 10 has been opened. For example, the non-volatile memory 22 may record a single data point of the door being open since the last reset of memory 22.

[0043] When power is restored to elevator system 2, microcontroller 24 reads the contents of non-volatile memory 22 and sends them to elevator controller 18. This also happens to all elevator safety devices 16. This notifies elevator controller 18 whether any of the landing doors 10 were open during the power supply interruption 19. If the contents of memory 22 indicate that any of the landing doors 10 were open during the power supply interruption 19, elevator controller 18 restarts operation of elevator system 2 in check mode. However, if memory 22 indicates that none of the landing doors 10 were open during the interruption, elevator controller 18 immediately activates full operation mode without any manual input.

[0044] Although this disclosure has been described in detail with reference to only a limited number of examples, it should be readily understood that this disclosure is not limited to these examples. Rather, this disclosure may be modified to incorporate any number of variations, modifications, substitutions, or equivalent arrangements not described to date but equivalent in scope to this disclosure. Furthermore, although various examples of this disclosure have been described, it should be understood that aspects of this disclosure may include only some of the described examples. Therefore, this disclosure is not to be construed as limited by the foregoing description, but only by the scope of the appended claims.

Claims

1. An elevator system (2), comprising: Terminal door (10); A landing door sensor (14) is arranged to detect the state of the landing door (10); Power supply (19), which is arranged to power the elevator system (2); An elevator controller (18) is arranged to control the elevator system (2); as well as An elevator safety device (16) is arranged to monitor the landing door (10), the elevator safety device (16) comprising: A power supply (20), arranged independently of the power supply (19) of the elevator system (2), supplies power to the landing door sensor (14); and A memory (22) is arranged to record the state of the landing door (10) detected by the landing door sensor (14) when the landing door sensor (14) is powered by the power supply (20). The elevator controller (18) is arranged to control the elevator system (2) according to the state of the landing doors (10) recorded by the memory (22), and The elevator controller (18) is characterized in that it receives information from the landing door sensor (14) independently of the elevator safety device (16) and controls the elevator system (2) based on the information received from the landing door sensor (14) independently of the elevator safety device (16).

2. The elevator system (2) according to claim 1, characterized in that The elevator safety device (16) is arranged to use the power supply (20) to power the landing door sensor (14) when the power supply (19) of the elevator system (2) is interrupted, and to disconnect the landing door sensor (14) from the power supply (20) when the power supply (19) of the elevator system (2) is activated.

3. The elevator system (2) according to any preceding claim, characterized in that, The power source (20) includes a battery, a capacitor, or a supercapacitor.

4. The elevator system (2) according to any preceding claim, characterized in that, The elevator safety device (16) is arranged to report the recorded status of the landing door (10) to the elevator controller (18) of the elevator system (2) after the power supply (19) of the elevator system (2) is interrupted.

5. The elevator system (2) according to claim 4, characterized in that The elevator safety device (16) includes a microcontroller (24) arranged to act as an interface between the memory (22) and the elevator controller (18).

6. The elevator system (2) according to any preceding claim, characterized in that The memory (22) is arranged to record a single data point indicating whether the floor door (10) is open at any point in time since the last reset of the memory (22).

7. The elevator system (2) according to any preceding claim, characterized in that, The memory (22) includes non-volatile memory.

8. The elevator system (2) according to any preceding claim, characterized in that, The power supply (20) is arranged in series with the landing door sensor (14).

9. The elevator system (2) according to any preceding claim, characterized in that, The memory (22) is arranged in series with the landing gate sensor (14).

10. The elevator system (2) according to claim 1, characterized in that The elevator controller (18) is configured to activate a check mode if the memory (22) indicates that the landing door (10) is open, and to activate a normal operation mode if the memory (22) indicates that the landing door (10) is not open.

11. The elevator system (2) according to any one of claims 1 to 10, characterized in that: The landing door sensor (14) includes a switch that completes an electrical connection between a first electrical terminal (28) and a second electrical terminal (30) when the landing door (10) is closed, and disconnects the electrical connection when the landing door (10) is opened; as well as The power supply (20) is arranged to be connected to the first terminal (28) of the switch; as well as The memory (22) is arranged to be connected to the second terminal of the switch.

12. The elevator system (2) according to any of claims 1 to 11, characterized by The elevator system (2) includes: Multiple floor gates (10); Multiple landing door sensors (14), each landing door sensor (14) arranged to detect the status of the corresponding landing door (10); and A first elevator safety device (16) is arranged to monitor the first set of landing doors (10) and a second elevator safety device (16) is arranged to monitor the second set of landing doors (10).

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