HK1216919B - Elevator door with a door contact switch - Google Patents

Description

Elevator door with door contact switch

Technical Field

The invention relates to a switching device for an elevator door for providing a door contact signal. The invention also relates to a method for providing such a door contact signal by means of such a switching device.

Background

The elevator installation has an elevator car and an elevator door, in particular a car door and a shaft door. The shaft door is provided, for example, with at least one door contact switch, by means of which the following is monitored: whether the shaft door is unlocked. The door contact switches arranged on the individual shaft doors are connected to a safety circuit. When one of the shaft doors is unlocked, the safety circuit is interrupted. The elevator car can then only travel when all the shaft doors of the elevator installation are latched. In addition, other states or positions of such elevator doors, in particular the open state or the closed state, can be monitored by means of door contact switches.

WO 2006036146 shows a switching device for monitoring a door leaf belonging to an elevator door. In addition to the door leaf, the elevator door also comprises a door frame, wherein the door leaf can latch onto the door frame. The switching device has a large number of magnets and also a large number of proximity sensors. The magnet is arranged on the door leaf and the proximity sensor is fixed on the door frame. Each proximity sensor corresponds to exactly one individual magnet. The magnets have a defined geometric arrangement with respect to one another. The defined geometric arrangement is likewise embodied by the proximity sensor in the following manner: so that the magnet simultaneously activates the proximity sensor when the door leaf transitions to its latched position. That is, each proximity sensor is spaced apart from its corresponding magnet by the same spacing. With the switching device thus defined, it is possible to avoid: the unauthorized person assumes, by means of a permanent magnet attached to the proximity sensor, that the relevant elevator door is in the latched position, although the elevator door is, for example, still open.

A problem with such switching devices is that the distance of the magnet from such a trigger latching position of the proximity sensor assigned to it can also be influenced by a faulty position of, for example, a damaged door leaf. This means that: a deviation of the magnet from the movement path provided for it in the vicinity of the latching position of the door leaf means that the latching position itself is displaced, which in turn leads to a malfunction of the elevator door and thus to a standstill of the elevator installation.

Disclosure of Invention

The invention aims to provide a switch device aiming at an elevator door and reducing failure rate.

The object is achieved by a switching device for an elevator door for providing a door contact signal, comprising: detecting a space; a plurality of proximity sensors, wherein the proximity sensors are adjacently arranged on the detection space; and a magnet which is movable in the detection space, wherein for at least one position of the magnet in the detection space, a sensor signal generated by the magnet can be generated by means of each of the proximity sensors, so that incorrect positions of the magnet in the detection space are compensated or compensated for by means of an evaluation of the sensor signals, wherein the sensor signals are dependent on the distance of the magnet from the proximity sensors.

The object is also achieved by means of an elevator door with such a switching device.

The object is also achieved by a method for providing a door contact signal, wherein the method is carried out by means of a switching device comprising a magnet, a plurality of proximity sensors, a detection space, and the proximity sensors are arranged on the detection space, with the following method steps:

generating, for a position of the magnet in the detection space, a first sensor signal related to a spacing of the magnet from a first one of the proximity sensors,

a second sensor signal is generated relating to a spacing of the magnet from a second one of the proximity sensors for a same position of the magnet in the detection space.

When only the defined switching distance of the magnet distance proximity sensor represents a criterion for switching the respective door contact state, a functional failure of the electrical circuit of the elevator door, which can be switched by means of the magnet, can occur. In this way, the spacing of the elevator door elements, which is critical for carrying out the switching process, can be reliably determined only when the magnet is moved with respect to the proximity sensor along a movement path on the basis of which the switching device is calibrated.

It is common, however, that the different components of an elevator door change during their operation due to external influences in the following manner: so that the magnet no longer moves about the axis of movement along which the proximity sensor is disposed. This may be caused, for example, by deformation of the door leaf or wear of the guide elements guiding the door leaf. The critical spacing of the elevator door components at the time point of the switching process may change, corresponding to the movement of the magnet in the environment of the proximity sensor which is thus changed.

The design of the switching device is thus modified in such a way that this modification of the elevator door has as little influence as possible on the critical spacing. By means of a large number of proximity sensors, which each generate a sensor signal in dependence on a specific distance of the proximity sensor from the respective magnet, it is achieved that the switching process is triggered independently of changes occurring in the elevator door as a result of external influences in the case of a predetermined critical distance. Thus, by evaluating the sensor signal, it is possible to compensate for incorrect positions of the magnet in the detection space.

In a development of the switching device, the proximity sensor is formed by a hall sensor. The hall sensor is a proximity sensor of simple construction and therefore functions correspondingly reliably.

In a development of the switching device, the proximity sensor is arranged substantially on one side of the axis of movement of the magnet. Alternatively to this, the proximity sensors may be arranged substantially on both sides of the axis of movement of the magnet. With this alternative, a possible way of evaluating the sensor signal in a simple manner is given.

Improvements in the switching apparatus include two proximity sensors or three proximity sensors which are preferably not arranged along a straight line. Irrespective of how the external influence acts on the elevator door, a certain minimum number of proximity sensors is required in order to be able to determine the position of the magnet inside the detection space and then to continuously comply with the described critical spacing of the elevator door components during switching of the switching device. When it can be expected that: if the axis of movement of the magnet is moved only along a plane in the detection space of the switching device on the basis of external influences, then only two proximity sensors are required for this purpose. However, when the elevator door part is changed on the basis of external influences in such a way that the axis of movement of the magnet can be changed at will in the detection space, three proximity sensors are required in order to continuously comply with the described critical spacing of the elevator door part during switching of the switching device.

The improvement of the switching device comprises an evaluation unit which is designed in such a way that, by means of the evaluation of the sensor signal, the door contact state is switched when the magnet enters the detection space with a predetermined depth of penetration. In this way, the possibility is achieved that the sensor signal of the proximity sensor, which is dependent on the position of the magnet in the detection space, is processed and then a door contact signal is generated.

The evaluation unit can be designed in such a way that a reference signal value, which is a signal value of the sensor signal generated in the reference position of the magnet, can be stored in the evaluation unit, and the reference signal value can be compared with a signal value of the sensor signal generated in the current position of the magnet. Thus, the influence of external influences on the elevator door can be measured. At the same time, the current position of the magnet can be detected from the reference position of the magnet in the detection space or is also prevented from changing too much for that reason. Thus, the elevator door can be prevented from malfunctioning by virtue of predictive maintenance.

In a further development of the switching device comprising an evaluation unit, in which the lowest value can be stored, the evaluation unit is designed in such a way that the door contact state is switched only when the signal value is higher than the lowest value. By means of this additional safety measure, functional malfunctions of the switching device can be prevented, for example, if all other criteria for the switching process of the switching device are met.

A development of the switching device has a self-test unit which generates a magnetic pulse, wherein the self-test unit acts on the at least one proximity sensor in such a way that a signal value is generated by means of this pulse. By means of such a self-test unit for the sensor signal acting on the proximity sensor, it is possible to detect an occurring malfunction of the switching device. When the switching device is completely powered normally, the magnetic pulses of the self-test unit trigger the signal values of the proximity sensor. Accordingly, the sensor signal is influenced by the signal value. When evaluating the sensor signal yields: if the sensor signal is not influenced or is influenced in an unexpected manner by the self-test unit, the cause may be, for example, a malfunction of the switching device that can be eliminated by a service person.

The improvement scheme of lift-cabin door has: a latching device comprising two parts which can be latched to one another, wherein the parts which can be latched to one another are preferably a latch and a stop, or two parts which can be moved relative to one another, wherein the at least two parts which can be moved relative to one another are at least one door leaf and a door frame, wherein a proximity sensor is fixed on a first of the parts, and wherein a magnet is fixed on a second of the parts. This arrangement of proximity sensor and magnet enables the monitoring of the locking, opening or any operating state of the door leaf or the latching state of the elevator door.

Drawings

The invention is explained in detail below with the aid of the figures. Wherein:

fig. 1 shows an elevator door with a latch arrangement;

fig. 2A, 2B show a switching device for an elevator door according to the prior art;

fig. 3 shows a switching device for an elevator door;

fig. 4A shows a switching device for an elevator door according to a first embodiment variation;

FIG. 4B shows a signal profile of the switching device shown in FIG. 3A;

fig. 5A shows a switching device for an elevator door according to a second embodiment variation;

FIG. 5B shows a signal profile of the switching device shown in FIG. 5A; and

fig. 6 shows a switching device for an elevator door according to a third embodiment variation.

Detailed Description

Fig. 1 shows an elevator door 2 arranged in an elevator installation. The elevator door 2 can be designed as a car door or as a shaft door arranged on the floor 12. The elevator door 2 comprises a door frame 8 and a first door leaf 6.1. Additionally, the elevator door may have a second door leaf 6.2 and/or a latching device 10 for latching the door leaf 6.1.

The latching device 10 has a latch 16 and a mechanical stop 14. The latch 16 can be coupled to the first door leaf 6.1, for example, and the stop 14 can be fastened to the second door leaf 6.2 or to the door frame 8. When the locking bolt 16 engages with the mechanical stop 14, the first door leaf and optionally also the second door leaf 6.1, 6.2 are prevented from performing an opening movement. For monitoring the latching state, the switching device 4 can be arranged on the latching device 10.

In fig. 2A, 2B, the opening and closing device 4 for the elevator door 2 according to the prior art is shown in a simplified manner. The elevator door 2 comprises a door leaf 6 and a door frame 8 shown in their closed position. The opening and closing device 4 for monitoring the locking position of the door leaf 6 comprises a magnet 20 and a proximity sensor 22. The magnet 20 is fixed to the door leaf 6. The proximity sensor 22 is fixed to the door frame 8 and has a detection gap SA. The detection spacing SA expresses the maximum spacing between the magnet 20 and the proximity sensor 22 sufficient to generate the door contact signal S.

Fig. 2A shows the elevator door 2 in a state where the adjustment of the opening and closing device 4 is completed by a serviceman. The maintenance personnel can determine the fixed position of the proximity sensor 22 and/or the magnet 20 at calibration in the following manner: when the door leaf 6 has the maximum clearance distance W from the door frame 8, a door contact signal S is output, at which the locking position is detected. This calibration is based on the detection pitch SA. Accordingly, the gate contact signal S is interrupted in the following cases, namely: the door leaf 6 is moved in the opening direction O in such a way that the distance between the magnet 20 and the proximity sensor 22 is greater than the detection distance SA. The magnet 20 moves along the movement axis B, on which it is arranged, when the door leaf 6 is moved in the opening direction O or the closing direction C, depending on the adjustment.

Fig. 2B shows the door leaf 6 in its locked position after an external influence has caused a change in the components of the elevator door 2. Such a change may occur, for example, due to deformation of the door leaf 6 by elevator passengers or due to wear of the guide elements of the door leaf 6. Accordingly, when the door leaf 6 is moved in the opening direction O or the closing direction C, the magnet 20 is no longer moved along the movement axis B, on which it is arranged, but along the modified movement axis B'. Since the detection distance SA does not change substantially from the moment when the maintenance person performs the calibration of the switching device 4, it follows from fig. 2B: the switching process of the switching device takes place with a maximum gap spacing W' that changes relative to the maximum gap spacing W. Accordingly, the gate touch signal S is output only when the maximum gap spacing W' of this change is lower. In the worst case, the door leaf 6 can abut against the door frame 8, without the door contact signal S detecting the locked position of the door leaf 6, since the resulting distance of the magnet 20 from the proximity sensor 22 is greater than the detection distance SA. When the door contact signal S is indispensable for the continued operation of the elevator installation, this temporarily stops the operation of the elevator installation until the switching device 4 is readjusted by the serviceman.

Fig. 3 shows an exemplary switching device 4 according to the invention. The switching device 4 comprises a magnet 20, a detection space DR and at least two proximity sensors 22a, 22b, 22 c. Furthermore, the switching device 4 can have an evaluation unit 26. The proximity sensors 22a, 22b, 22c are arranged adjacent to the detection space DR. For example, the switch device 4 includes a switch body 21 on which proximity sensors 22a, 22b, 22c are fixed.

In the case of monitoring the state of the latch explained with reference to fig. 1, the magnet 20 can be arranged on the latch, the proximity sensors 22a, 22b, 22c on the stop, or vice versa. Alternatively, the switching device 4 can be provided for monitoring the opening or closing state of the door leaf or any other operating state. For this purpose, the proximity sensors 22a, 22b, 22c can be arranged on the first door leaf, and the magnet 20 can be arranged (preferably fixed) on the second door leaf, if present, or on the door frame, or vice versa. When the door leaf or latch is in a position to be monitored or in the immediate vicinity of said position, the magnet 20 has a depth of immersion ET into the detection space DR. Thus, the magnet 20 is at least partially immersed in the detection space DR. The switching device 4 is designed or can be adjusted in such a way that the door contact state is switched when entering the detection space DR at a predetermined depth ET.

Depending on the distance of the magnet 20, which is at least partially immersed in the detection space DR, from the respective proximity sensor 22a, 22b, 22c, at least one of the proximity sensors 22a, 22b, 22c generates a sensor signal 24a, 24b, 24c which can correspond to the respective proximity sensor 22a, 22b, 22 c. At least one sensor signal 24a, 24b, 24c can be transmitted to the evaluation unit 26. When at least two sensor signals 24a, 24b, 24c are present, the penetration depth ET of the magnet 20 can be determined by evaluating the sensor signals 24a, 24b, 24c and, if applicable, the existing direction of movement of the door leaf. For example, the evaluation can be performed with the aid of a mathematical algorithm which defines the dependence of the sensor signal 24a, 24b, 24c on the distance of the magnet 20 from the corresponding proximity sensor 22a, 22b, 22 c. When the immersion depth ET of the magnet 20 corresponds to the preset immersion depth ET, the gate contact state can be switched by means of the output gate contact signal S. Thus, the gate contact signal S is expressed in terms of the signal: the door leaf has reached or passed the locking position, the opening position or the latching position or an operating position determined arbitrarily beforehand.

Fig. 4A, 5A, 6 show the components of an elevator door with a switching device 4 according to different embodiment variants. The elevator door has the constituent components of the elevator door shown in fig. 1. The switching device 4 comprises a magnet 20, a detection space DR, at least two proximity sensors 22a, 22b, 22c, 22d and may have an evaluation unit 26. The proximity sensors 22a, 22b, 22c, 22d are arranged adjacent to the detection space DR. The magnet 20 is fixed to the door leaf 6 and the proximity sensors 22a, 22c are fixed to the door frame 8 (fig. 4A), or vice versa (fig. 6). Alternatively, the magnet 20 can be fastened to the first door leaf 6.1 and the proximity sensors 22a, 22b can be fastened to the second door leaf 6.2 (fig. 5A).

When the at least one at least partially open door leaf 6, 6.1, 6.2 executes the closing movement C, the magnet 20 sinks into the detection space DR. In this case, the magnet 20 is moved relative to the detection space DR along a predetermined movement axis B, wherein the movement axis B' may be changed by external influences. When the magnet 20 is in detectable proximity to the respective proximity sensor 22a, 22b, 22c, 22d, the proximity sensor 22a, 22b, 22c, 22d generates a sensor signal 24a, 24b, 24c, 24d, respectively, that can correspond to the proximity sensor 22a, 22b, 22c, 22 d. The sensor signals 24a, 24b, 24c, 24d can be transmitted to the evaluation unit 26 and evaluated in the evaluation unit 26. When the evaluation (and if necessary the comparison) of the sensor signals 24a, 24b, 24c, 24d by the evaluation unit 26 yields: the door leaf 6.1 outputs a door contact signal S when it is latched or opened or assumes a defined operating position depending on the purpose of the switching device 4. Such a door contact signal S can be used, for example, to switch on a safety circuit of the elevator installation. When evaluating the sensor signals 24a, 24b, 24c, 24d by the evaluation unit 26, it follows: the door leaf 6.1 is no longer latched or locked or opened or no longer occupies a defined operating position, the door contact signal S is stopped.

When the following can be taken as starting points, namely: when the axis of movement B' of the magnet 20 in the detection space DR is changed substantially only along a plane (e.g., according to the illustrated plane shown in fig. 4A, 5A) after the influence of changing the elevator door components occurs, at least two proximity sensors 22a, 22B, 22c are required. In contrast, when the magnet 20 may have an arbitrarily changed movement axis B' after the influence of changing the elevator door components occurs in the detection space DR, the proximity sensors 22a, 22B, 22c (e.g., fig. 6) are required in a number of at least three, preferably not arranged along a straight line.

Fig. 4A shows a switching device 4 according to a first embodiment variant, in which the proximity sensors 22a, 22c are arranged substantially on both sides of a movement axis B, B' of the magnet 20, which may be changed by an external influence.

Fig. 5A shows a switching device 4 according to a second embodiment variant, in which the proximity sensors 22a, 22b are arranged substantially on one side of the movement axis B, B' of the magnet 20, which can be changed by external influences.

Fig. 4B and 5B show signal distribution diagrams of the switching device 4 shown in fig. 4A or 5A. In these signal profiles, the signal values (in particular the signal strengths) of the sensor signals 24a, 24b, 24c are represented as a function of the penetration depth ET of the magnet 20 into the detection space DR. In the illustrated fig. 4A, 5A, the higher signal strength corresponds to a smaller distance of the magnet 20 from the associated proximity sensor 22a, 22b, 22 c. Based on the sensing characteristics of the respective proximity sensors 22a, 22b, 22c, it is known that: in the case of the detected signal values 24a, 24b, 24c, how far the magnet 20 is from the respective proximity sensor 22a, 22b, 22 c. Thus, the position of the magnet 20 in the detection space DR can be known on the basis of the sensor signals 24a, 24b, 24c of the at least two proximity sensors 22a, 22b, 22 c. In this way, by evaluating the sensor signals 24a, 24b, 24c in the evaluation unit 26: when the magnet 20 enters the detection space DR at the preset depth ET, the gate contact state is switched by the gate contact signal S.

The evaluation unit 26 can be designed in such a way that, when the switching device 4 is adjusted, the signal values 24a, 24b, 24c of the proximity sensors 22a, 22b, 22c can be stored as reference signal values 25a, 25b, 25c when the magnet 20 has a predetermined depth of penetration ET. Thus, the reference signal values 25a, 25b, 25c express: the reference position of the magnet 20 is at a predetermined depth of submersion ET.

By comparing the signal values of the sensor signals 24a, 24b, 24c occurring at the predetermined depth of penetration ET during the operation of the elevator door with the reference signal values 25a, 25b, 25c, it can be determined that: at the predetermined depth of penetration ET, the instantaneous position of the magnet 20 deviates to a certain extent from the position of the magnet 20 during the adjustment of the switching device 4. Thus, it is possible to identify: the external influence plays a large role in the deformation of the elevator door. Furthermore, it is possible to evaluate: in which time interval the readjustment of the elevator doors has been completed without the elevator installation being exposed to a risk of stoppage due to a malfunction of the elevator doors. The aforementioned stoppage of the elevator installation can be prevented by outputting the calibration request signal when a predeterminable deviation of the signal values of the sensor signals 24a, 24b, 24c from the reference signal values 25a, 25b, 25c occurs. When it is determined that there is a deviation in generating the calibration request signal, it is possible to take into account, for example, the tolerance of the elevator door parts in batch and the size of the detection space DR of the switching device 4.

An exemplary distribution of the respective signal values of the sensor signals 24a ', 24B ' which are generated on the basis of the changing movement axis B ' along which the magnet 20 is moved is shown in dashed lines in fig. 5B. According to the illustration shown, the switching device 4 can be calibrated with the proximity sensors 22a, 22b arranged substantially on one side of the movement axis B, B' of the magnet 20, which can be changed, in such a way that the criterion for the output door contact signal S is matched to the signal values 24a, 24b of the proximity sensors 22a, 22 b; 24a ', 24 b' are equally high. The lowest value M stored in the evaluation unit 26 is necessary in this evaluation scheme for preventing the occurrence of false alarms when the signal values 24a, 24 b; 24a ', 24 b' are smaller than said minimum value M and output the gate contact signal S.

Fig. 6 shows a switching device 4 for an elevator door according to a third embodiment variant. The switching device 4 can comprise a self-test unit 28.1, 28.2 in the presence of the evaluation unit 26. The self-test units 28.1, 28.2 (which for example comprise at least one electromagnet acting on the proximity sensors 22a, 22b, 22c, 22d) generate magnetic pulses at a frequency that can be preset. The magnetic pulses act on the proximity sensors 22a, 22b, 22c, 22d, which in turn generate signal values corresponding to the pulses 22a, 22b, 22c, 22 d. The signal values generated by means of the pulses superimpose the signal profile of the sensor signals 24a, 24b, 24c, 24d, which is generated on the basis of the detection of the magnet 20. Thus, by evaluating the sensor signals 24a, 24b, 24c, 24d within the evaluation unit 26, it is possible to identify: whether the proximity sensors 22a, 22b, 22c, 22d or the switching device 4 process the generated pulses in a manner that can be expected. When this is not the case, it may mean that the switching device 4 is malfunctioning. Accordingly, a fault signal can be generated, which for example generates a maintenance request for maintaining the switching device 4.

Claims (15)

1. A switching device (4) of an elevator door (2) for providing a door contact signal (S), the switching device (4) comprising: a detection space (DR); a plurality of proximity sensors (22a, 22 b; 22c, 22d), wherein the proximity sensors (22a, 22 b; 22c, 22d) are arranged adjacent to the detection space (DR); and a magnet (20) which can be moved in the detection space (DR), wherein for at least one position of the magnet (20) in the detection space (DR) a sensor signal (24a, 24 b; 24c, 24d) generated by the magnet (20) can be generated by means of each of the proximity sensors (22a, 22 b; 22c, 22d) in order to compensate for an incorrect position of the magnet (20) in the detection space (DR) by means of an evaluation of the sensor signals (24a, 24 b; 24c, 24d), wherein the sensor signals (24a, 24 b; 24c, 24d) are dependent on a distance of the magnet (20) from the proximity sensors (22a, 22 b; 22c, 22d), wherein an evaluation unit (26) is provided which is designed in such a way that: by evaluating all sensor signals (24a, 24 b; 24c, 24d), the door contact state is switched when the magnet (20) enters the detection space (DR) at a predetermined depth of penetration (ET).

2. The switching device (4) according to claim 1, wherein the proximity sensor (22a, 22 b; 22c, 22d) is formed by a Hall sensor.

3. The switching device (4) according to claim 1 or 2, wherein the proximity sensor (22a, 22B) is arranged substantially on one side of the axis of movement (B) of the magnet (20).

4. The switching device (4) according to claim 1 or 2, wherein the proximity sensors (22a, 22c) are arranged substantially on both sides of the axis of movement (B) of the magnet (20).

5. The switching device (4) according to claim 1 or 2, wherein the switching device (4) comprises two proximity sensors (22a, 22b) or three proximity sensors (22a, 22 b; 22c, 22 d).

6. The switching device (4) according to claim 1, wherein the evaluation unit (26) is designed in such a way that the signal values of the sensor signals (24a, 24b, 24c) which occur in the reference position of the magnet (20) are reference signal values (25a, 25b, 25c) which can be stored in the evaluation unit (26), and the reference signal values (25a, 25b, 25c) can be compared with the signal values of the sensor signals (24a, 24b, 24c) which occur in the current position of the magnet (20).

7. The switching device (4) according to claim 1 or 6, wherein the lowest value (M) can be stored in the evaluation unit (26), and the evaluation unit (26) is designed in such a way that: the gate contact state is only switched when the signal value (24a, 24b, 24c) is higher than the minimum value (M).

8. Switching device (4) according to claim 1 or 2, having a self-test unit (28.1, 28.2) which generates a magnetic pulse, which acts on at least one of the proximity sensors (22a, 22 b; 22c, 22d) in such a way that a signal value (24a, 24b, 24c, 24d) is generated by means of such a magnetic pulse.

9. A method for providing a door contact signal (S), wherein the method is carried out by means of a switching device (4) comprising a magnet (20), a plurality of proximity sensors (22a, 22 b; 22c, 22d), a detection space (DR), the proximity sensors (22a, 22 b; 22c, 22d) being arranged on the detection space (DR), having the following method steps:

generating a first sensor signal (24a) related to a spacing of the magnet (20) from a first one (22a) of the proximity sensors for a position of the magnet (20) in the detection space (DR),

generating a second sensor signal (24c) related to a spacing of the magnet (20) from a second one (22c) of the proximity sensors for a same position of the magnet (20) in the detection space (DR),

wherein the method is provided for compensating for an incorrect position of the magnet (20) in the detection space (DR).

10. The method according to claim 9, having the further method steps of: the first and second sensor signals (24a, 24c) are evaluated by means of an evaluation unit (26) of the switching device (4),

the door contact state is switched when the magnet (20) enters the detection space (DR) with a predetermined depth of penetration (ET).

11. Method according to claim 10, wherein, on the basis of the evaluation, a depth of immersion (ET) of the magnet (20) into the detection space (DR) is determined.

12. The method according to claim 10 or 11, with the following additional method steps:

in the reference position of the magnet (20), a first reference signal value (25a) of the first sensor signal (24a) is determined,

in the reference position of the magnet (20), a second reference signal value (25b) of a second sensor signal (24b) is determined,

storing the first reference signal value (25a) and the second reference signal value (25b) in an evaluation unit (26),

comparing the reference signal value (25a, 25b) with a signal value of the sensor signal (24a, 24b) corresponding to the current position of the magnet (20),

when it is recognized that the deviation between the reference position of the magnet (20) and the current position is too high based on the comparison of the reference signal values (25a, 25b) and the signal value that can correspond to the current position of the magnet (20), a calibration request signal is output.

13. Elevator door (2) with a switching device (4) according to any one of claims 1 to 8.

14. Elevator door (2) according to claim 13, elevator door (2) having: a latching device (10) comprising two components (14, 16) which can be latched to one another, or an elevator door (2) having at least two components (6, 6.1, 6.2, 8) which can be moved relative to one another, wherein the at least two components which can be moved relative to one another are at least one door leaf (6, 6.1, 6.2) and a door frame (8), wherein a proximity sensor (22a, 22 b; 22c, 22d) is fastened to a first of the components (14, 16, 6, 6.1, 6.2, 8) and a magnet (20) is fastened to a second of the components (14, 16, 6, 6.1, 6.2, 8).

15. Elevator door (2) according to claim 14, wherein the components (14, 16) that can latch with each other are a latch (16) and a stop (14).