Elevator safety system, elevator system and method for elevator car collision protection

Abstract

An elevator safety system (110) comprising an elevator car safety unit (31) arranged on or at least mechanically connected, preferably in a fixed manner, with an elevator car (10), at least one ranging target (52), and a ranging device (50) mounted on the elevator car (10) for determining a distance (101) between the ranging target (52) and the ranging device (50). The elevator car safety unit (31) is arranged in connection with the ranging device (50) and configured to generate an output signal (102) on the basis of the determined distance (101).

Description

Technical Field

[0001] This invention generally relates to elevators. Specifically, but not exclusively, this invention relates to elevator safety systems and methods for elevator systems having multiple elevator cars movable within the same elevator shaft. Background Technology

[0002] An elevator is known to have multiple cars that can move within the same elevator shaft. A collision between one elevator car and any object in the shaft's path could result in loss of life for passengers. Therefore, solutions to prevent collisions are needed. Summary of the Invention

[0003] The purpose of this invention is to provide an elevator safety system, elevator system, and method for collision protection of elevator cars. Another purpose of this invention is to at least reduce the risk of collision between the elevator car and other elevator cars and / or equipment or structures in the elevator shaft.

[0004] The object of the present invention is achieved by elevator safety systems, elevator systems and methods for collision protection in elevator systems, as defined by their respective independent claims.

[0005] According to a first aspect, an elevator safety system is provided. The elevator safety system includes an elevator car safety unit disposed on or at least mechanically connected to the elevator car, preferably in a fixed manner. The elevator safety system also includes at least one ranging target and a ranging device mounted on the elevator car for determining the distance between the ranging target and the ranging device. In a preferred embodiment, the distance can be determined in the direction of movement of the elevator car, for example, in the longitudinal direction of the elevator shaft. The elevator car safety unit is arranged in association with the ranging device and configured to generate an output signal based on the determined distance.

[0006] In addition, the elevator car safety unit can be configured to initiate the stopping of the elevator car based on a determined distance, for example, when the determined distance is below a safe distance.

[0007] In some embodiments, the elevator car safety unit can be configured to determine the speed of the elevator car and, based on the speed and a determined distance, and optionally, the direction of movement of the elevator car relative to the ranging target, such as approaching or moving away from the ranging target, initiate the stopping of the elevator car, for example, by outputting a signal.

[0008] In various embodiments, the ranging target can be a static object, such as a mechanical marker or surface portion or reflector, or other corresponding component used by the ranging device to determine distance.

[0009] In various embodiments, the at least one ranging target may be arranged on an elevator car, i.e., at the end of an elevator shaft relative to another elevator car with a ranging device, or a section of the elevator shaft may be temporarily reserved for maintenance operations.

[0010] Furthermore, the at least one ranging target may be included in a safety device. Additionally, the at least one safety device may be arranged to change the position of the ranging target between an active and inactive position. Further, in the active position, the ranging target may be arranged such that distances can be determined, for example, extended to a position where the ranging device can determine the distance between them. Alternatively or additionally, the at least one safety device may include an actuator and a support element for the ranging target, wherein the actuator and the support element are configured to change the position of the ranging target.

[0011] In some embodiments, at least one safety device may be arranged at the door zone of the elevator shaft or at the turning station of the elevator shaft, or a section of the elevator shaft may be reserved for maintenance operations.

[0012] Alternatively or additionally, the elevator safety system may include an elevator control unit configured to operate at least one safety device, such as changing its position.

[0013] Furthermore, the at least one safety device may be arranged at the turning station, and the position of the ranging target is adapted based on the position of the turning station and / or the state of the turning station locking device.

[0014] In some embodiments, the elevator car safety unit may also be arranged to control the movement of the elevator car during normal operation, for example, by controlling the mover of a linear motor.

[0015] According to a second aspect, an elevator system is provided. The elevator system includes a linear motor arranged to move at least one elevator car, preferably multiple elevator cars, within an elevator shaft. The elevator system also includes an elevator safety system according to the first aspect.

[0016] According to a third aspect, a method for collision protection of an elevator car is provided. The method includes:

[0017] - The distance between the elevator car and a target located in the elevator shaft or another elevator car is determined by a distance measuring device on the elevator car.

[0018] - The elevator car will stop based on the determined distance.

[0019] In some embodiments, the method may include determining the speed of the elevator car, wherein starting may then include starting and stopping based on the determined distance and speed and optionally the direction of movement of the elevator car relative to the ranging target and / or safety device.

[0020] This invention provides an elevator safety system, elevator system, and method for collision protection of elevator cars. The advantage of this invention over known solutions is that it allows multiple elevator cars to move within the same elevator shaft and improves safety associated with movement. Even if collisions cannot be completely avoided, the risk of collision is at least reduced. Furthermore, various embodiments of this invention allow for maintenance work on certain sections and / or extensions of the elevator shaft at multiple different construction phases, because the safety system can be configured to permanently or temporarily prevent the elevator car from moving into certain sections of the shaft.

[0021] Based on the following detailed description, various other advantages will become apparent to those skilled in the art.

[0022] Unless otherwise explicitly stated, the terms “first,” “second,” etc., are used herein to distinguish one element from other elements and do not specifically prioritize or order them.

[0023] The exemplary embodiments of the invention presented herein should not be construed as limiting the applicability of the appended claims.

[0024] The verb "comprising" is used herein as an open-ended limitation, which does not exclude the presence of features not described. Unless otherwise expressly stated, the features recited in the dependent claims may be freely combined with each other.

[0025] Novel features considered characteristic of the invention are specifically set forth in the appended claims. However, the structure and operation of the invention itself, as well as its additional objects and advantages, will be best understood when read in conjunction with the accompanying drawings and from the following description of specific embodiments. Attached Figure Description

[0026] The accompanying drawings illustrate some embodiments of the invention by way of example and not limitation.

[0027] Figure 1 An elevator system according to an embodiment of the present invention is illustrated schematically.

[0028] Figure 2 An elevator safety system according to an embodiment of the present invention is illustrated schematically.

[0029] Figure 3 An elevator safety system according to an embodiment of the present invention is illustrated schematically.

[0030] Figure 4 A steering station according to an embodiment of the present invention is illustrated schematically.

[0031] Figure 5 A flowchart of a method according to an embodiment of the present invention is shown. Detailed Implementation

[0032] Figure 1 An elevator system 100 according to an embodiment of the present invention is schematically illustrated. The elevator system 100 may include at least one or more elevator cars 10 moving within an elevator shaft 13 or elevator car passage 13. The elevator car 10 may include a first electrical converter unit 12, such as a frequency converter or inverter, and / or a first energy storage device (e.g., one or more batteries). The first electrical converter unit 12 may be used to operate a mover disposed to the elevator car 10 to move the car 10 along the elevator shaft 13. Other electrically operated devices, such as lighting, doors, user interfaces, emergency rescue devices, etc., may also be present in the elevator car 10. The first electrical converter unit 12 or other electrical converter units, such as inverters or rectifiers, may be used to operate one or more of the other devices of the elevator car 10. The first energy storage device is preferably electrically connected to the first electrical converter unit 12, for example, to intermediate circuitry of the frequency converter, for providing power to the first electrical converter unit 12 and / or for storing electrical energy provided by the first electrical converter unit or other electrical converter units or other power sources.

[0033] Preferably, the elevator system 100 includes at least two landings, each having landing doors 19 or openings 19. The elevator car 10 may also include doors. Although in Figure 1 The diagram shows two sets or two "columns" of horizontally separated, vertically aligned landings, but it can also have only one column of landings like a traditional elevator, or more than two columns, such as three columns.

[0034] Regarding the elevator shaft 13, it may, for example, define a substantially enclosed volume in which the elevator car 10 is adapted and configured to move. The walls may be, for example, concrete, metal, or at least partially glass, or any combination thereof. The elevator shaft 13 herein essentially refers to any structure or passage along which the elevator car 10 is configured to move.

[0035] like Figure 1 As can be seen from the description of elevator system 100, elevator system 100 is a multi-car elevator system, in which one or more elevator cars 10 can move vertically and / or horizontally along elevator shaft 13 according to the direction of stator beam 16. Based on similarities in this respect... Figure 1 In some embodiments, one or more elevator cars 10 can be configured to move along a plurality of vertical and / or horizontal stator beams 16, for example... Figure 1 Two beams in the shaft. Some stator beams 16 are shown in dashed lines to indicate their optionality. However, it should be recognized that stator beams 16 may also be present in the middle section of the shaft 13, such as... Figure 1 As shown. Furthermore, one, several, or all of the stator beams can be inclined.

[0036] The stator beam 16 is part of the linear motor of the elevator system 100 for moving one or more elevator cars 10 in the elevator shaft 13. The stator beam 16 may preferably be arranged in a fixed manner, i.e., stationary relative to the elevator shaft 13, for example, fixed to the wall of the shaft by fasteners, which may be arranged to be rotatable at the turning station 11, for example including turning devices, such as turning gears or turning platforms.

[0037] Elevator system 100 may include an elevator control unit 1000 for controlling the operation of elevator system 100. Elevator control unit 1000 may be a separate device or may be included in or as part of other components of elevator system 100, such as in or as part of electrical converter unit 12. Elevator control unit 1000 may also be implemented in a distributed manner, such that, for example, one part of elevator control unit 1000 may be included in electrical converter unit 12, while another part is included in elevator car 10. Elevator control unit 1000 may also be distributed in more than two locations or in more than two devices.

[0038] The elevator control unit 1000 may include one or more processors, one or more volatile or non-volatile memories for storing computer program code and any data values, and possibly one or more user interface units. The aforementioned components may be communicatively connected to each other, for example, via an internal bus.

[0039] The processor of the elevator control unit 1000 can be configured to implement at least some of the method steps described below. This method can be implemented by arranging the processor to execute at least a portion of computer program code stored in memory, causing the processor, and thus the elevator control unit 1000, to implement one or more of the method steps described below. Therefore, the processor is arranged to access memory and retrieve and store any information from and within the memory. For clarity, the term "processor" herein refers to any unit suitable for tasks such as processing information and controlling the operation of the elevator control unit 1000. This operation can also be implemented using a microcontroller solution with embedded software. Similarly, the memory is not limited to a specific type of memory, but any type of memory suitable for storing the described information can be applied in the context of this invention.

[0040] Furthermore, the elevator system 100 may preferably include safety devices 46, for example at the ends of the shaft 13 and / or in the door zone and / or in sections of the elevator shaft 13 temporarily reserved for maintenance operations, and / or at the turning station 11. These safety devices 46 may be, for example, buffers or movable stops commonly used in elevator shafts 13 or other known safety devices.

[0041] Furthermore, the elevator car 10 may preferably include an elevator car controller 30 for controlling various functions of the elevator car 10. These functions may at least include movement-related operations, such as participating in or fully executing operations to control a mover operatively coupled to the elevator car 10 to move it. The elevator car controller 30 may preferably be arranged in communicative connection with the elevator control unit 1000. Additionally, car speed and / or position sensors 35 (such as…) may be present. Figure 3 As shown, it is configured to provide elevator car speed and / or position information to the elevator car controller 30, for example, based on absolute or relative positioning.

[0042] Figure 2 An elevator safety system 110 according to an embodiment of the present invention is schematically illustrated. The elevator safety system 110 may include an elevator car safety unit 31 disposed on or at least mechanically connected to the elevator car 10, preferably in a fixed manner. Furthermore, the elevator safety system 110 may include at least one ranging target 52 disposed in the elevator shaft 13. Further, the elevator safety system 110 may include a ranging device 50 disposed on the elevator car 10 for determining a distance 101 between the ranging target 52 and the ranging device 50. The ranging device 50 may also be connected to the elevator car safety unit 31, for example, to provide it with the determined distance. The elevator car safety unit 31 is arranged to be connected to the ranging device 50 and configured to generate an output signal 102 based on the determined distance 101. Therefore, the output signal 102 may include a stop command for stopping the elevator car 10. In various embodiments, the determined distance between the target 52 and the ranging device 50 is in the direction of movement of the elevator car 10, and in many cases, in the longitudinal direction of the elevator shaft 13.

[0043] In various embodiments, the ranging target 52 can be, for example, a static or dynamic mechanical marker, the position of which can be selectively changed. A static mechanical marker can be positioned in its place and primarily maintain its position. An example of a static mechanical marker could be a marker positioned at the end of the elevator shaft 13 to indicate that the elevator car 10 is approaching the end. A dynamic mechanical marker allows its position to be changed, for example, by means of the elevator control unit 1000. Thus, a dynamic mechanical marker can be positioned in its active or inactive position. A dynamic mechanical marker can be used to selectively prevent or allow the elevator car 10 to move too close to or past the marker. The elevator car 10 can be prevented from moving to a landing or detour station 11 by a mechanical marker indicating that the car 10 should not move there. For example, there may be another car 10 at the landing, or the detour station 11 may be in an incorrect position or not locked.

[0044] Therefore, the ranging target 52, together with the ranging device 50, can be configured to provide information about the distance between them, which can be used to allow or stop the movement of the elevator car 10 if, for example, the distance becomes too small, such as below a safe distance. Stopping can be achieved by providing a stop signal 102 to a stopping device, such as a brake used to stop the car 10.

[0045] Furthermore, the elevator car safety unit 31 can be connected to a safety speed and / or position sensor 51, which is arranged to determine the speed and / or position of the elevator car 10, for example, based on an absolute or relative position sensor. The safety speed and / or position sensor 51 can therefore be arranged to provide a speed and / or position signal 103 to the elevator car safety unit 31. The signal 103 may also include information related to the direction of movement.

[0046] In various embodiments, the ranging target 52 may be a static object, such as a static mechanical marker or surface portion or reflector, or other corresponding component for the ranging device used to determine distance.

[0047] In various embodiments, the at least one ranging target 52 may be installed on the elevator car 10, at the end of the elevator shaft 13, or a section of the elevator shaft 13 may be temporarily reserved for maintenance operations.

[0048] Furthermore, the at least one ranging target 52 may be included in the safety device 46, for example, at the end of the shaft 13. The option to specifically include the ranging target 52 in the safety device 46 is determined by… Figure 2The dotted lines in section 3 indicate this. These safety devices 46 can be, for example, buffers or movable stops, such as rotatable buffers. Alternatively or additionally, dynamic safety devices 46 can be arranged at the door area of ​​the landing. Furthermore, safety devices 46 can be associated with the turning station 11 in the hoistway 13, for example, indicating the position of the turning device of the turning station 11 and / or the locking status of the turning station locking device. This will be described in more detail later.

[0049] In some embodiments, the at least one safety device 46 may be arranged to change the position of the ranging target 52 between an active position and an inactive position. In the active position, the ranging target 52 is preferably able to work in conjunction with the ranging device 50 to determine the distance between them.

[0050] Furthermore, the at least one safety device 46 may include an actuator and a support element for the ranging target 52, wherein the actuator and the support element are configured to change the position of the ranging target 52. The actuator may include, for example, a motor or other such actuating device, or an element of another entity, such as an element of the steering station 11, which changes its position in response to operation of said entity. Thus, the actuator can be arranged to change the position of the support element on which the ranging target 52 is mounted.

[0051] In various embodiments, the ranging target 52 can extend from its active position to a location where the ranging device 50 can determine the distance between them. The operation of the ranging device 50 can be based, for example, emitting electromagnetic waves and then based on received signals, such as reflected signals. If the ranging device 50 is, for example, an ultrasonic, infrared proximity, and / or laser ranging device, the ranging target 52 can be positioned in its active position to reflect signals emitted by the ranging device 50. In an inactive position, the ranging target 52 can be moved, for example, retracted, such that no signal is reflected back to the ranging device 50, or the reflected signal has characteristics indicating an inactive position, thereby enabling the ranging device 50 and / or the elevator car safety unit 31 to identify the inactive position of the ranging target 52.

[0052] Therefore, in various embodiments, the at least one safety device 46 may be arranged, for example, at the door zone of the elevator shaft 13 or at the turning station 11 of the elevator shaft 13 to control, for example, prevent the elevator car 10 from moving therein, or reserve a section of the elevator shaft 13 for maintenance operations.

[0053] In some embodiments, the elevator car safety unit 31 can be configured to determine the speed of the elevator car 10, for example via a safety speed and / or position sensor 51, and to initiate a stop of the elevator car 10 based on the speed and a determined distance 101. The speed can be based on an overspeed limit, which can be fixed or have a specific profile toward the position of the ranging target 52, such as a decreasing ramp. Alternatively, the current speed can be utilized so that, based on the speed and the determined distance, the stop of the elevator car can be initiated such that the magnitude of deceleration does not become excessive when the elevator car 10 is stopped before reaching the position of the ranging target 52.

[0054] Furthermore, the at least one safety device 46 may be arranged at the turning station 11, and the position of the ranging target 52 is adapted based on the position of the turning station 11 and / or the state of the turning station locking device.

[0055] In various embodiments, the elevator control unit 1000 may be configured to operate at least one safety device 46, for example, changing its position between an operating position and an inactive position. In some cases, as described above, this may simultaneously change the position of the ranging target 52 between its active and inactive positions.

[0056] Figure 3 An elevator safety system 110 according to an embodiment of the present invention is illustrated schematically. The elevator system 100 may include at least an elevator control unit 1000 or a portion thereof, such as one or more hoistway section safety controllers 56A-56N.

[0057] The hoistway section safety controllers 56A-56N can be configured to monitor and control, for example, receive the position, direction of movement, and speed of at least one elevator car 10 arranged in the elevator hoistway section. These sections can be, for example, vertical, horizontal, or inclined hoistway sections. Figure 1 Only the vertical and horizontal portions are shown in the diagram. Therefore, the elevator shaft 13 may include two vertical portions and two, or optionally four, horizontal portions defined by the stator beam 16. The elevator control unit 1000 or shaft portion safety controllers 56A-56N may be configured to determine whether movement of the elevator car 10 within certain portions of the elevator shaft 13 is permitted. Therefore, the elevator control unit 1000 may be configured to authorize at least one elevator car 10 to move within a portion of the shaft 13, for example, via a linear motor.

[0058] Furthermore, the elevator system 100 may include at least one or preferably multiple elevator car controllers 30 communicatively connected to the elevator control unit 1000 or its shaft section safety controllers 56A-56N. Item 111 may refer to receiving / providing at least the position, direction of movement, and speed of at least one elevator car arranged in the elevator shaft 13 or its shaft section. Item 112 may refer to authorizing at least one elevator car to move, for example, by a linear motor, in an authorized shaft section or its shaft section of the elevator shaft 13. Item 113 may refer to a stop signal provided by the elevator controller 30, for example based on a signal received from the elevator control unit 1000.

[0059] In various embodiments, the stopping of the elevator car 10 can therefore be initiated by the elevator car controller 30 connected to the elevator control unit 1000 or by the elevator car safety unit 31, for example by output signal 102, thus involving the operation of the elevator car stopping system 60, such as including the elevator car brake and / or braking or safety stop device in the elevator shaft 13.

[0060] Therefore, according to various embodiments, the elevator safety system 110 can preferably operate independently of other safety systems including the elevator car controller 30. Thus, if the elevator control unit 100 connected to the elevator car controller 30 fails to stop the elevator car 10 even when it should stop, the elevator safety system 110 according to various embodiments can prevent the elevator car 10 from entering or exiting an undesired hoistway position 13.

[0061] Figure 4 A steering station 11 according to an embodiment of the present invention is schematically shown. The steering station 11 may include a steering device 41. In various embodiments, the steering device 41 may include a rotatable platform, and a stator beam component 42 of the steering station 11 is connected thereto, similar to or corresponding to the stator beam 16 of the electric linear motor of the elevator system 100. Figure 4 In this context, the steering device 41 is, for example, similar to a turntable having a rotation axis 43. From Figure 4 As can be seen, two parallel stator beams 16 extend from below to the steering station 11. Another set of two parallel stator beams 16 extends to the right side of the steering station 11.

[0062] Therefore, the primary function of the steering station 11 is to enable the elevator car 10 to move between the two sets of stator beams 16. Thus, the steering device 41 must be in the correct position relative to the stator beams 16, with the elevator car 10 moving out of and / or into the stator beams 16 to prevent derailment. Of course, the correct position depends on the direction from which the elevator car 10 approaches the steering station 11 or the direction in which the elevator car 10 will move. As will become clear, the steering device 41 is therefore configured to rotate the stator beam component 42 of the steering device 41, or at least allow the stator beam component 42 of the steering device 41 to rotate.

[0063] The steering station 11 may additionally include a safety device 46, namely, in this case, a locking device 46A, 46B of the steering station 11. The purpose of the locking devices 46A, 46B is to lock the steering device 41 in its position, thereby preventing its rotation, preferably at least as long as the locking devices 46A, 46B are in their locked state (i.e., in a locked state).

[0064] Elevator system 100 can be configured to use two independent sensor systems to monitor the status of locking devices 46A and 46B. The systems can be of different types relative to each other, such as those used in [other applications]. Figure 4 As shown in the diagram. If the turning station 11 is not in the correct position when the elevator car 10 enters or leaves station 11, the elevator car 10 may fall from the hoistway beam 16. This can be advantageously prevented by various embodiments as described herein.

[0065] Regarding one of the independent sensor systems, locking devices 46A, 46B include locking plungers 51A, 51B and locking device sensors 55A, 55B operably coupled to the locking plungers 51A, 51B for determining the position of the locking plungers 51A, 51B, thereby determining the state of locking devices 46A, 46B. Locking device sensors 55A, 55B may include two sensor elements (in...) Figure 4 (Shown in black fill), they are adapted such that one of them is arranged to indicate whether the locking plungers 51A, 51B are in the fully extended state, i.e., the lock is in the open state, or in some other state. The other of the two sensor elements is arranged to indicate whether the locking plungers 51A, 51B are in the fully retracted state, i.e., the lock is in the closed state, or in some other state.

[0066] One of the sensors 55A may also be arranged to provide its reading to the elevator control unit 1000 or to a first hoistway section safety controller 56A that is communicatively connected to the elevator control unit 1000. Alternatively or additionally, the first hoistway section safety controller 56A may be included in the elevator control unit 1000. Another sensor 55B may also be arranged to provide its reading to the elevator control unit 1000 or to a second hoistway section safety controller 56B that is communicatively connected to the elevator control unit 1000. Alternatively or additionally, the second hoistway section safety controller 56B may be included in the elevator control unit 1000.

[0067] Regarding the other one in the independent sensor system and according to Figure 4 In one embodiment, a ranging target 52 may be present, i.e., in this case, indicating elements 52A, 52B, such as physical markers, mounted on locking plungers 51A, 51B. Locking plungers 51A, 51B can therefore act as actuators for the safety device 46.

[0068] Two elevator car safety units 31 are shown, representing elevator car safety units 31 of different elevator cars 10, for example, approaching the turning station 11 from different directions. The elevator car safety units 31 can also be configured to detect ranging targets 52, etc., in other parts of the elevator shaft 13, such as those associated with the ends of the elevator shaft 13 and / or the door zones of the landings, to... Figure 4 A similar arrangement is shown for the turning station 11. Therefore, when the elevator car 10 approaches the turning station 11, it can be arranged to determine the state of the turning station 11, such as whether it is in the correct position relative to the elevator car 10.

[0069] Therefore, additionally, if the states of locking devices 46A and 46B permit, and optionally, if no other car 10 is at the turning station 11, the elevator control unit 1000 can be configured to authorize the elevator car 10 to enter the turning station 11. In various embodiments, the elevator car safety unit 31 can independently determine the states of locking devices 46A and 46B, and even initiate the stopping of the car 10, which preferably involves operating the elevator car stopping system 50, such as including the elevator car brake and / or braking or safety stop devices in the elevator shaft 13.

[0070] Figure 5 A flowchart of a method according to an embodiment of the present invention is shown.

[0071] Step 600 refers to the initiation phase of the method. Suitable equipment and components are obtained and assembled into a system for operation.

[0072] Item 610 may refer to determining the distance between the elevator car 10 and a ranging target 52 arranged in the elevator shaft 13 or another elevator car 10 by means of a ranging device 50 on the elevator car 10.

[0073] Optional item 620 may refer to determining the speed of the elevator car 10. Some optional stages of the method are described in... Figure 5 The middle part is represented by a dashed line.

[0074] Item 630 may refer to initiating the stop of the elevator car 10 based on a determined distance and optionally based on a determined speed.

[0075] Method execution can stop at step 699.

Claims

1. An elevator safety system (110), characterized in that... It includes: An elevator car safety unit (31) is arranged on the elevator car (10) or at least mechanically connected to the elevator car (10); At least one ranging target (52); and A ranging device (50) is installed on the elevator car (10) to determine the distance (101) between the ranging target (52) and the ranging device (50). The elevator car safety unit (31) is arranged to be connected to the ranging device (50) and configured to generate an output signal (102) based on the determined distance (101). The at least one ranging target (52) is included in the safety device (46); The at least one safety device (46) is configured to change the position of the ranging target (52) between an active position and an inactive position.

2. The elevator safety system (110) according to claim 1, wherein, The distance (101) is in the direction of movement of the elevator car (10).

3. The elevator safety system (110) according to claim 1 or 2, wherein, The ranging target (52) is a static object.

4. The elevator safety system (110) according to any one of claims 1-3, wherein, The at least one ranging target (52) is installed on the elevator car (10), at the end of the elevator shaft (13), or a section of the elevator shaft (13) is temporarily reserved for maintenance operations.

5. The elevator safety system (110) according to any one of claims 1-4, wherein, At the activity location, the ranging target (52) is arranged such that the distance can be determined.

6. The elevator safety system (110) according to any one of claims 1-5, wherein, The at least one safety device (46) includes an actuator and a support element for the ranging target (52), wherein the actuator and the support element are configured to change the position of the ranging target (52).

7. The elevator safety system (110) according to any one of claims 1-6, wherein, The at least one safety device (46) is installed at the door zone of the elevator shaft (13) or at the turning station (11) of the elevator shaft (13), or a section of the elevator shaft (13) is reserved for maintenance operations.

8. The elevator safety system (110) according to any one of claims 1-7, wherein, The elevator car safety unit (31) is configured to determine the speed of the elevator car (10) and initiate the stopping of the elevator car (10) based on the speed and a determined distance (101).

9. The elevator safety system (110) according to any one of claims 1-8, comprising an elevator control unit (1000) configured to operate the at least one safety device (46).

10. The elevator safety system (110) according to any one of claims 1-9, wherein, The at least one safety device (46) is arranged at the turning station (11), and the position of the ranging target (52) is adapted based on the position of the turning station (11) and / or the state of the turning station locking device (46A, 46B).

11. An elevator system (100) comprising a linear motor arranged to move at least one elevator car (10) in an elevator shaft (13), characterized in that, The elevator system (100) includes the elevator safety system (110) according to any one of claims 1-10.

12. A method for collision protection of an elevator car, characterized in that, The method includes: - Determine (610) the distance between the elevator car and a ranging target arranged in the elevator shaft or another elevator car by means of a ranging device on the elevator car, wherein the ranging target is included in a safety device arranged to change the position of the ranging target between an active position and an inactive position; and - Start (630) the elevator car stops according to the determined distance.

13. The method of claim 12, further comprising determining (620) the speed of the elevator car, wherein, The initiation includes initiating the stop based on the determined distance and speed.

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