Position sensor for escalators and moving walkways

Abstract

The invention relates to a position switch biasing device (60) for a position switch (50) which has a button element (51) displaceable in a first direction (L). The position switch biasing device (60) comprises a fastening element (70) for fastening to the position switch (50), and comprises a biasing element (80). The biasing element (80) is connected linearly displaceably to the fastening element (70) and is coordinated with the position switch (50) in such a way that, when a position switch biasing device (60) is mounted on the position switch (50), the biasing element (80) of the biasing device is movable telescopically in the first direction (L) of the button element (51). Without any action of an external force, the biasing element (80) holds the button element (51) of the position switch (50) in a partially depressed, biased state.

Description

[0001] POSITION SENSOR FOR ESCALATORS AND MOVING WALKWAYS

[0002] The present invention relates to a position sensor for escalators and moving walkways and in particular to a biasing device for a position switch of such a position sensor.

[0003] As an efficient means of transportation, escalators and moving walkways are frequently used in buildings such as airports, train stations, subway stations, shopping centers, and department stores. The operational safety requirements of such passenger conveyor systems are very high, as the personal safety of their users must be ensured. Therefore, it is particularly important to monitor the escalator's travel status in real time. A critical area in escalators or moving walkways is a gap between their conveyor belt and a base plate of the balustrade base located on either side of the conveyor belt. Position switches can be used to monitor the gap, as disclosed in US Pat. No. 6,405,847 B1. These position switches are designed to detect whether the base plate is deformed transversely to the direction of travel under the application of force, thus widening the gap.This indicates that, for example, an object or even a user's limbs are being drawn into this gap, which is why the escalator or moving walkway must be stopped immediately.

[0004] However, it has been determined that the commercially available position switches used to monitor the base plate are not sensitive enough and therefore do not emit a contact signal if the base plate is even slightly deformed. This poses a certain safety risk. While solutions using optical detection systems that can detect deformation of the base plate are known, the necessary installation space is often lacking to retrofit an optical detection system to an existing escalator equipped with commercially available position switches. Furthermore, such systems are expensive and potentially susceptible to contamination.

[0005] The object of the present invention is to minimize the aforementioned safety risk. Commercially available position switches should also be able to be used for this purpose.

[0006] This problem is solved by a position switch pretensioning device for a position switch, by a position sensor with a position switch and such a position switch pretensioning device, and by an escalator or moving walkway with such a position sensor. The position switch has a pushbutton element that is displaceable along a first direction. The pushbutton element is held in an off position by means of a spring element acting counter to the first direction. If the pushbutton element is subjected to a force acting in the first direction and against the spring element, the pushbutton element can be moved from its open position (switch path open) to an on position (switch path closed).

[0007] The position switch preload device comprises a fastening element for attaching the device to a position switch and a preload element that is connected to the fastening element for linear displacement. The preload device is adapted to the position switch in such a way that, when the position switch preload device is mounted on the position switch, the preload element can be moved telescopically along the first direction of the pushbutton element. The preload element holds the pushbutton element of the position switch in a partially engaged, preloaded state even without external force.

[0008] In other words, a position sensor is created by assembling a conventional position switch with a position switch preload device. Due to this assembly, the sensing element is pressed into the switch housing of the position switch by the position switch preload device to a predetermined insertion depth, thus shortening the required travel distance of the position switch to its on position. This significantly increases the sensitivity of a conventional position switch, so that the position switch is triggered even when the degree of deformation of the object to be tested is small. By arranging a telescopically movable preload element and the fastening element on the position switch, the sensing element of the position switch can be given an initial insertion depth.In one embodiment of the position switch pretensioning device, the pretensioning element comprises at least one guide lug. The at least one guide lug is connected to the fastening element in a linearly displaceable manner. Furthermore, the guide lug has a guide lug projection, which, in cooperation with a stop surface of the fastening element, specifies a maximum distance of the pretensioning element relative to the fastening element. In other words, the guide lug projection and the stop surface form a mechanical stop. This prevents the pretensioning element from being removed from the fastening element or from being pushed away by the spring element of the position switch beyond this maximum distance.

[0009] In a further embodiment of the position switch preload device, the preload element has a truncated cone top surface and a truncated cone side surface. These are formed on the side of the preload element facing away from the fastening element. Using the truncated cone top surface with a smaller area for contacting the object to be tested or the base plate has the advantage of allowing more precise monitoring of the local area, as the influence of the flatness of the base plate is reduced. The smaller the truncated cone top surface, the more direct the transmission of a deflection of the base plate to the preload element.

[0010] In a further embodiment of the position switch preload device, the preload element has a pre-press projection. This projection is arranged on the side of the preload element facing the fastening element. When the position switch preload device is mounted on the position switch, the pre-press projection is in direct contact with the sensing element. The offset or partially engaged state of the sensing element is determined by selecting a press-in distance extending between the stop surface and the pre-press projection in the first direction.

[0011] In a further embodiment of the position switch pretensioning device, the

[0012] The preload element has at least one limiting projection directed toward the fastening element, which, in conjunction with the fastening element, limits the engagement depth of the preload element relative to the fastening element. The limiting projection limits the maximum engagement depth and protects the pushbutton element from excessive external forces, thus preventing the destruction of internal contact elements and the spring element of the position switch.

[0013] In a further embodiment of the position switch preload device, the fastening element comprises a telescopic sleeve and a fastening base. The inner diameter of the telescopic sleeve is matched to the sensing element of a position switch intended for assembly with the position switch preload device in such a way that it is larger than the outer diameter of the sensing element. This allows the sensing element to be arranged in the interior of the telescopic sleeve, extending through the interior space to the preload element. The telescopic sleeve thus protects the sensing element from, for example, dirt, lubricants, and splash water, but also from transverse forces that could act on the sensing element perpendicular to the first direction.

[0014] In a first variant, the telescopic sleeve is provided with a guide groove for interaction with the guide nose projection. When the position switch preload device is assembled, the guide nose of the preload element is located outside the telescopic sleeve. The guide nose projection engages in the guide groove. The aforementioned stop surface preferably forms one of the two ends of the guide groove.

[0015] In a second variant, the telescopic sleeve is also provided with a guide groove for interaction with the guide nose projection. However, when the position switch preload device is assembled, the guide nose of the preload element protrudes into the interior space defined by the inner diameter of the telescopic sleeve. The guide nose projection also engages in the guide groove. The stop surface mentioned above preferably forms one of the two ends of the guide groove in the second variant as well.

[0016] In a third variant, a circumferential fastening projection is arranged on the telescopic sleeve. The fastening projection is intended, in cooperation with the guide nose projection of the preloading element, to limit the displacement path of the preloading element counter to the first direction L. In other words, the fastening projection has the stop surface for the guide nose projection. To ensure that the guide nose projection meets the stop surface, the fastening projection protrudes in a second direction, and the guide nose projection protrudes in a direction opposite to the second direction. The second direction is arranged orthogonally to the first direction.

[0017] In a further embodiment of the position switch pretensioning device, the orthographic projection of the fastening projection onto an imaginary plane and the orthographic projection of the guide nose projection onto the imaginary plane overlap each other by at least 80%, with the imaginary plane being orthogonal to the first direction. The smaller of the two orographic projections is always chosen as the basis for the percentage of overlap.

[0018] In a further embodiment of the position switch preload device, the preload element has a threaded insert in which an adjusting screw for adjusting the preloaded state is arranged as a pre-pressing projection. The adjusting screw not only compensates for manufacturing tolerances of the position switch preload device, but also, in particular, can adjust the actual switching travel of the position switch and thus its sensitivity. To prevent the adjusting screw from becoming displaced due to vibrations during operation, it can be secured in the threaded insert after adjustment, for example, using anaerobic adhesives. It is also possible to slightly deform the threaded insert, thus creating a stiff, self-locking screw connection.

[0019] To achieve a position sensor with greater sensitivity, a conventional or commercially available position switch is combined with a position switch preload device. For this purpose, the fastening element is firmly connected to the switch housing of the position switch. The pre-press projection of the preload element, which is connected to the fastening element in a linearly movable manner, engages a sensing element of the position switch. Due to the geometric conditions, in particular the selected press-in distance, the preload element holds the sensing element of the position switch in a partially engaged, preloaded state without the application of external force. In other words, by mounting the position switch preload device on the position switch, the sensing element is engaged and held in the switch housing against the spring force of the spring element.The press-in distance is selected so that the contacts of the position switch are just not closed and no flashover of a sensor current applied to the contacts can occur.

[0020] Position sensors modified in this way can now be used in an escalator or moving walkway. Such passenger transport systems comprise a conveyor belt and base plates arranged on both sides of the conveyor belt. To monitor a gap between the base plate and the conveyor belt, the escalator or moving walkway has at least one position sensor of the aforementioned type. This position sensor is arranged on a side surface of the base plate facing away from the conveyor belt. Preferably, the first direction of the position sensor is arranged orthogonally to this side surface. The prestressing element is also directed against this side surface. Preferably, the truncated cone cover surface of the prestressing element touches the adjacent side surface, but without exerting a force on the prestressing element in the normal state.If vibrations during operation cause the position switch to respond, a narrow air gap of, for example, a maximum of 0.4 mm can be provided between the truncated cone cover surface of the preload element and the adjacent side surface when attaching the position sensor.

[0021] Embodiments of the invention are described below with reference to the accompanying drawings. Identical or equivalent features have the same reference numerals. They show:

[0022] Figure 1: schematically shows a partial cross-section through an escalator, wherein only part of a step and part of a balustrade base of the escalator are shown in order to show a possible installation of a position sensor according to the invention;

[0023] Figure 2: schematically shows a position sensor with a commercially available position switch and with a position switch pretensioning device according to a first embodiment;

[0024] Figure 3: an enlarged sectional view of the detail X shown in Figure 2;

[0025] Figure 4: a three-dimensional representation of the overall structure of the position switch pretensioning device according to Figures 2 and 3;

[0026] Figure 5: a three-dimensional representation of a pretensioning element of the position switch pretensioning device shown in Figure 4;

[0027] Figure 6: a three-dimensional representation of a fastening element of the position switch pretensioning device shown in Figure 4;

[0028] Figure 7: a sectional view of a second embodiment of a position switch pretensioning device;

[0029] Figure 8: a sectional view of a third embodiment of a position switch pretensioning device; and

[0030] Figure 9: a sectional view of a fourth embodiment of a position switch pretensioning device with an adjusting screw.

[0031] The terminology used is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the terms "comprising" and the like indicate the presence of specified features, steps, acts, and / or components, but do not preclude the presence or addition of one or more other features, steps, acts, or components.

[0032] The terms "length", "width", "top", "bottom", "front", "back", "left", "right", "vertical", "horizontal", "upper", "lower", "inside", "outside", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings and are used only for the purpose of describing the present invention and primarily for convenience of description. A device or element must have a specific orientation, be constructed, and operate in a specific orientation, so these specifications should not be construed as limiting the invention.

[0033] Figure 1 schematically shows a partial cross-section through an escalator 1. Its physical structure and mode of operation have been known for decades, so they will not be discussed in detail here. In this partial cross-section, only part of a step 3 of a conveyor belt 5 and part of a balustrade base 7 of the escalator 1 are shown in order to illustrate a possible installation of a position sensor 40 according to the invention. As is known, during operation of the escalator 1, the step 3 or the conveyor belt 5 moves relative to a stationary base plate 9 of the balustrade base 7, which is arranged to the side of the conveyor belt 5. According to applicable standards such as EN-115, the gap width B of the gap 15 required for functional purposes between the base plate 9 and the step 3 must not be greater than 3 mm.This prevents objects such as shoes or users' fingers from being drawn into gap 15 and causing serious injury. Although the base plate 9 is made of solid materials such as sheet steel, its sheet-like structure can cause it to be pushed away into a deformed position 21, shown by a dot-dash line, when a force F is applied from the direction of step 3. This results in the width B of gap 15 becoming greater than 3 mm, which can lead to the aforementioned accidents.

[0034] To detect deformed layers 21 of the base plate 9, position sensors 40 are arranged behind the base plate 9 at predetermined intervals along a direction of movement R (not vertical, but actually oblique to the plane of the drawing) of the conveyor belt 5. These position sensors 40 each have a position switch biasing device 60 and a position switch 50, the sensing element 51 of which is directed toward the base plate 9. In other words, the position sensors 40 are arranged next to a side surface 13 of the base plate 9 facing away from the conveyor belt 5.

[0035] If the pushbutton element 51 of the position switch 50 is actuated or engaged to a certain degree due to a deformed layer 21 of the base plate 9, an electrical contact 55 in the position switch 50 closes (see Figure 2), thereby transmitting a signal current S to an escalator control 15 of the escalator 1. Based on this signal current S, the escalator control 15 disconnects a drive motor 17 of the escalator 1 from the power supply (not shown) and activates its service brake 19, stopping the conveyor belt 5.

[0036] If during this process the engaged path of the push button element 51 is very small and does not close the electrical contact 55, the position switch 50 also does not transmit a signal current S. This means that if the degree of deformation of the base plate 9 is very small and therefore harmless, the position switch 50 is not triggered.

[0037] The most important components of the position switch 50 are shown schematically in Figure 2. The pushbutton element 51 is held in an off-position A by a spring element 52, whose spring force FF acts counter to a first direction L. The first direction L indicates the possible direction of displacement of the pushbutton element 51 from the off-position A to an on-position K. The contact 55 mentioned above has a contact tongue 53 and a contact projection 56, which is mechanically connected to the pushbutton element 51. Two electrical lines 54 lead into the interior of the position switch 50, one of the two lines 54 being electrically connected to the contact projection 56 via the spring element 52, and the other of the two lines 54 being electrically connected to the contact tongue 53.When the push button element 51 is actuated or engaged to the on-switching position K, the contact projection 56 touches the contact tongue 53 after traveling the switching path Y and electrically connects the two lines 54 to one another, so that the signal current S applied to one of the two lines 54 can flow.

[0038] It can also be seen from Figure 2 that without the use of a position switch pretensioning device 60, the pushbutton element 51 would protrude considerably further from the position switch 50. Upon actuation of the pushbutton element 51, a considerably longer switching travel Y' would have to be covered until the contact projection 56 touches the contact tongue 53. By attaching a position switch pretensioning device 60 to a conventional position switch 50, the latter reacts to considerably smaller deformed layers 21 of the base plate 9 by shortening the original switching travel Y by a pretensioning distance V. The sensitivity is thereby increased in proportion to the shortening of the original switching travel Y' compared to the actual switching travel Y. The pretensioning distance V is the difference between the original switching travel Y' and the actual switching travel Y.

[0039] Figures 2 to 6 show the aforementioned position switch pretensioning device 60 and its components in a first embodiment, which is why these figures are described together. The position switch pretensioning device 60 comprises a fastening element 70 and a pretensioning element 80. The fastening element 70 is firmly connected to a switch housing 57 of the position switch 50, for example by means of screws or an adhesive. Clamping elements, press connections, snap connections, welded connections, and the like can also be used for this purpose. Depending on the design, the fastening element 70 can be fastened to either side of the position switch 50, as long as the fastening element 70 and the position switch 50 can be securely connected to one another and the pretensioning element 80 has the correct functional alignment with the pushbutton element 51.

[0040] The preload element 80 and the fastening element 70 are connected to one another so as to be linearly displaceable relative to one another. In other words, a preload element 80 arranged on the position switch 50 can be moved telescopically within a predetermined displacement path along the first direction L and in the opposite direction. The preload element 80 bears against the sensing element 51 of the position switch 50 such that the sensing element 51 is in a preloaded state. As soon as a base plate 9 to be monitored is deformed and exerts a force F in the first direction L against the preload element 80, the sensing element 51 is engaged in the direction of the on position K upon overcoming the spring force FF of the spring element 52.

[0041] The fastening element 70 shown in Figures 2 to 6 has a fastening base 71 and a telescopic sleeve 72. Two opposing guide grooves 73 each extend in the first direction L from a stop surface 75 formed in the telescopic sleeve 72 to a base surface 76 of the fastening base 71 (see Figure 6). When the position switch pretensioning device 60 is mounted on the position switch 50, the base surface 76 rests against the position switch 50. The stop surface 75 is arranged parallel to the base surface 76 and at a distance T (see Figure 3).

[0042] The preload element 80 of the position switch preload device 60 has two parallel, projecting guide lugs 81, each with a guide lug projection 82, wherein the two guide lugs 81 also extend in the first direction L. Each of the guide lug projections 82 extends in a second direction Q, which is orthogonal to the first direction L. The guide lugs 81 are matched to the guide grooves 73 such that their guide lug projections 82 engage in the guide grooves 73 when the position switch preload device 60 is fully assembled. The guide lug projections 82, in cooperation with the stop surface 75 of the respective guide groove 73, specify a maximum distance M (see Figure 2) of the preload element 80 from the fastening element 70 and thus limit its displacement path counter to the first direction L.

[0043] Furthermore, the pre-tensioning element 80 has two parallel, projecting limiting projections 83, wherein the two limiting projections 83 also extend in the first direction L. The limiting projections 83, in cooperation with the fastening base 71, against which they rest after traveling an engagement depth E, specify a minimum distance of the pre-tensioning element 80 from the fastening element 70 and thus limit its displacement path in the first direction L. The engagement depth E must be greater than the actual switching path Y (see Figure 2) in order to ensure that, in the engaged state, the contact projection 56 sufficiently touches or contacts the contact tongue 53.

[0044] The preload element 80 also has a pre-press projection 86. Its projection surface 87 is arranged at a distance H from the guide nose projections 82. The projection surface 87 is intended to bear against the probe element 51 when the position switch preload device is mounted on a position switch 50. As can be easily seen, the preload distance V (see Figure 2) can be specified by selecting the distance H. In order to engage the projection surface 87, the probe element 51 projects into an interior space 77 defined by the telescopic sleeve 72, the inner diameter Dm of which must be larger than an outer diameter DAT of the probe element 51.

[0045] In the present embodiment, the preload element 80 is cylindrical. Furthermore, the preload element 80, including its guide lugs 81, its limiting projections 83, and the pre-pressing projection 86, is formed in one piece. The side of the preload element 80 facing away from the guide lugs 81, the limiting projections 83, and the pre-pressing projection 86 is truncated conically shaped and thus has a truncated cone cover surface 84 and a truncated cone outer surface 85. The use of the truncated cone cover surface 84 with a smaller area for contacting the object to be tested, i.e., the base plate 9, leads to more precise monitoring of the local area, as the influence of the flatness of the base plate 9 is reduced. The smaller the truncated cone cover surface 84, the more direct the transmission of a deflection of the base plate 9 to the preload element 80.

[0046] As Figures 2 to 6 show as a first variant of the position switch pretensioning device 60, when the position switch pretensioning device 60 is assembled, the guide lugs 81 are arranged outside the telescopic sleeve 72.

[0047] Figure 7 shows a second variant of the position switch pretensioning device 60, whose telescopic sleeve 72 is also provided with two oppositely arranged guide grooves 73 for interacting with the guide lug projections 82. However, when the position switch pretensioning device 60 of this variant is assembled, the guide lugs 81 of the pretensioning element 80 protrude into the interior space 77 defined by the inner diameter Dm of the telescopic sleeve 72. The guide lug projections 82 also engage in the respective guide groove 73. The stop surface 75 mentioned above also forms one of the two ends of the guide groove 73 in the second variant.

[0048] Figure 8 shows a third variant of the position switch pretensioning device 60. A circumferential fastening projection 74 is arranged on its telescopic sleeve 72. The fastening projection 74 interacts with the guide nose projection 82 of the pretensioning element 80 and limits the displacement path of the pretensioning element 80 counter to the first direction L. In other words, the fastening projection 74 has the stop surface 75 for the guide nose projection 82.

[0049] As can be clearly seen from Figure 8, the fastening element 70, or rather its telescopic sleeve 72, has no guide grooves or limiting projections. Due to the absence of guide grooves, the preloading element 80 can rotate freely about a central longitudinal axis 79 of the telescopic sleeve 72. The function of the limiting projections is performed by the two guide lugs 81, whose ends 78 are dimensioned such that the engagement depth E exists between them and the fastening base 71 when no force F acts on the preloading element 80.

[0050] In order for the guide nose projection 82 to hit the stop surface 75, the fastening projection 74 protrudes in a second direction Q and the guide nose projection 82 protrudes in a direction opposite to the second direction Q. The second direction Q is arranged orthogonally to the first direction L.

[0051] For all the above-mentioned and following variants of the position switch pretensioning device 60, the orthographic projection of the fastening projection 74 or the stop surface 75 onto an imaginary plane (not shown) and the orthographic projection of the guide nose projection 82 onto the imaginary plane overlap one another, wherein the imaginary plane is arranged orthogonal to the first direction L.

[0052] Figure 9 shows a sectional view of a fourth embodiment of a position switch pretensioning device 60 with an adjusting screw 89. Here, the pretensioning element 80 has a threaded insert 88, in which the adjusting screw 89 for adjusting the pretensioned state is arranged as a pre-pressing projection 86. The adjusting screw 89 not only compensates for manufacturing tolerances of the position switch pretensioning device 60, but also allows the actual switching travel Y (see Figure 2) of the position switch 50 and thus its sensitivity to be adjusted. To prevent the adjusting screw 89 from becoming displaced due to vibrations during operation, it can be secured in the threaded insert 88 after adjustment, for example, using anaerobic adhesives. It is also possible to slightly deform the threaded insert 88 during production, thereby creating a stiff, self-locking screw connection.For adjustment, the adjusting screw 89 has a hexagon socket hole 90 on its end, allowing adjustment using a hex key. Instead of the hexagon socket hole 90, other coupling types can also be used, for example, for slotted screwdrivers, Phillips screwdrivers, hexalobular screwdrivers, triangular wrenches, etc.

[0053] Although four variants of the position switch pretensioning device 60 are illustrated in Figures 1 to 9, it is obvious that the same functional principle of pretensioning a position switch 50 by means of a position switch pretensioning device 60 can also be implemented with differently designed fastening elements 70 and pretensioning elements 80. For example, the number of guide lugs 81 of a pretensioning element 80 is not limited to two. In particular, a pretensioning element 80 and / or a fastening element 70 can also be composed of multiple parts. Of course, the adjusting screw 89 and the threaded insert 88 can be used in any of the illustrated variants of the position switch pretensioning device 60. Finally, it should be noted that terms such as "having", "comprising", etc. do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a plurality.Reference signs in the claims are not to be considered as limitations.

Claims

Patent claims 1. Position switch preloading device (60) for creating a position sensor (40), which position sensor (40) can be used to monitor a gap (15) between a base plate (9) and a conveyor belt (5) of an escalator (1) or a moving walkway, wherein the position sensor (40) has a position switch (50) whose sensing element (51) is displaceable along a first direction (L) and is held in an off position (A) by means of a spring element (52) acting against the first direction (L), characterized in that the position switch preloading device (60) comprises a fastening element (70) for attaching to the position switch (50) and a preloading element (80), wherein the preloading element (80) is linearly displaceable and connected to the fastening element (70) and is thus adapted to the position switch (50).that in a position switch preloading device (60) mounted on the position switch (50), the preloading element (80) is telescopically movable along the first direction (L) of the keying element (51) and, without external force, the preloading element (80) holds the keying element (51) of the position switch (50) in a partially engaged, preloaded state.

2. Position switch preloading device (60) according to claim 1, wherein the preloading element (80) comprises at least one guide lug (81), wherein the at least one guide lug (81) is linearly displaceable and connected to the fastening element (70), and wherein the guide lug (81) has a guide lug projection (82) which, in conjunction with a stop surface (75) of the fastening element (70), defines a maximum distance (M) of the preloading element (80) to the fastening element (70).

3. Position switch preloading device (60) according to claim 1 or 2, wherein the preloading element (80) has a truncated cone top surface (84) and a truncated cone shell surface (85) adjoining the truncated cone top surface (84), which are arranged on a side of the preloading element (80) facing away from the fastening element (70).

4. Position switch preloading device (60) according to one of claims 1 to 3, wherein the preloading element (80) has a preload projection (86) which is arranged on a side of the preloading element (80) facing the fastening element (70) and is designed to be in direct contact with the sensing element (51) when the position switch preloading device (60) is mounted on the position switch (50).

5. Position switch preloading device (60) according to one of claims 1 to 4, wherein the preloading element (80) comprises at least one limiting projection (83) directed towards the fastening element (70), which in conjunction with the fastening element (70) limits a recess depth (E) of the preloading element (80) relative to the fastening element (70).

6. Position switch preloading device (60) according to any one of claims 1 to 5, wherein the fastening element (70) comprises a telescopic sleeve (72) and a fastening base (71) and an inner diameter (Dm) of the telescopic sleeve (72) is larger than an outer diameter (DAT) of the sensing element (51) of a position switch (50) provided for assembly with the position switch preloading device (60).

7. Position switch preloading device (60) according to claim 6, wherein the telescopic sleeve (72) is provided with a guide groove (73) for interaction with the guide lug projection (82), wherein, when the position switch preloading device (60) is mounted, the guide lug (81) of the preloading element (80) projects into the interior space (77) limited by the inner diameter (Dm) of the telescopic sleeve (72) and the guide lug projection (82) engages in the guide groove (73).

8. Position switch preloading device (60) according to claim 6, wherein the telescopic sleeve (72) is provided with a guide groove (73) for interaction with the guide lug projection (82), wherein, when the position switch preloading device (60) is mounted, the guide lug (81) of the preloading element (80) is arranged outside the telescopic sleeve (72) and the guide lug projection (82) engages in the guide groove (73).

9. Position switch preloading device (60) according to claim 6, wherein a circumferential mounting projection (74) is arranged on the telescopic sleeve (72), and the mounting projection (74) is provided to limit the displacement path of the preloading element (80) in conjunction with the guide lug projection (82) of the preloading element (80) in the first direction (L).

10. Position switch preloading device (60) according to claim 9, wherein the fastening projection (74) projects in a second direction (Q) and the guide lug projection (82) projects in a direction opposite to the second direction (Q), wherein the second direction (Q) is orthogonal to the first direction (L).

11. Position switch preloading device (60) according to claim 10, wherein the orthographic projection of the fastening projection (74) onto an imaginary plane and the orthographic projection of the guide nose projection (82) onto the same imaginary plane overlap each other by at least 80%, wherein the imaginary plane is arranged orthogonally to the first direction (L).

12. Position switch preloading device (60) according to one of claims 1 to 11, wherein the preloading element (80) has a threaded insert (88) in which an adjusting screw (89) for adjusting the preloaded state is arranged as a preload projection (86).

13. Position sensor (40) comprising a position switch (50) and a position switch preloading device (60) according to one of claims 1 to 12, wherein the fastening element (70) is rigidly connected to a switch housing (57) of the position switch (50) and the preload projection (86) of the preloading element (80) which is linearly displaceable with the fastening element (70) is in contact with a sensing element (51) of the position switch (50) and, without external force, the preloading element (80) holds the sensing element (51) of the position switch (50) in a partially engaged, preloaded state.

14. Escalator (1) or moving walkway with a conveyor belt (5) and a base plate (9) arranged laterally to the side of the conveyor belt (5), wherein the escalator (1) or moving walkway has at least one position sensor (40) according to claim 13 for monitoring a gap (15) between the base plate (9) and the conveyor belt (5) and which position sensor (40) is arranged on a side surface (13) of the base plate (9) facing away from the conveyor belt (5), wherein the first direction (L) of the position switch (50) of the position sensor (40) is arranged orthogonally to this side surface (13) and the pretensioning element (80) is directed towards this side surface (13).

15. Escalator (1) or moving walkway according to claim 14, wherein the prestressing element (80) with its truncated conical top surface (84) rests against the side surface (13) of the base plate (9).

Images