Aircraft boarding bridge safety protection device

Abstract

This invention discloses a safety protection device for a boarding bridge, comprising: a lifting platform for movably extending through the swing floor of the boarding bridge, having a first state extending upwards from the swing floor and a second state being received downwards within the swing floor; an elastic element connected to the lifting platform for stabilizing the lifting platform in the first state; a clutch drive mechanism capable of engaging with the lifting platform to drive it to the second state, or disengaging from the lifting platform to allow the elastic element to drive the lifting platform to the first state; and a detection device located below the swing floor and electrically connected to the lifting system of the boarding bridge for detecting the position of the lifting platform and transmitting a signal to the lifting system. In the event of an accident, the lower edge of the aircraft door pushes the lifting platform downwards to a certain position, and the detection device transmits a signal to the lifting system of the boarding bridge to control the emergency descent of the boarding bridge, avoiding damage to the aircraft door and the boarding bridge, improving boarding efficiency, and facilitating unmanned, fully automated boarding.

Description

Technical Field

[0001] This invention relates to a safety protection device for boarding bridges. Background Technology

[0002] A boarding bridge is a movable, liftable passageway used in airports to connect the terminal building and the aircraft. One end of the bridge connects to a boarding gate in the terminal, and the other end connects to the aircraft door. When the bridge connects to the aircraft, the bridge's access buffer slowly moves against the aircraft fuselage, adjusting the swing floor at the front of the access bridge to be roughly parallel to the aircraft door. When the height difference between the swing floor and the aircraft door is 15-20 cm, the access canopy, driven by the left and right sides, comes into contact with the aircraft fuselage surface. The automatic leveling mechanism then engages and moves against the aircraft. While the bridge is in automatic leveling mode, the operator places the door safety protection device under the aircraft door. This device detects uncontrolled movement between the aircraft and the bridge and transmits a signal to the bridge's lifting system to trigger an emergency descent, preventing interference between the aircraft door and the bridge's swing floor that could damage either.

[0003] However, the current boarding bridge door safety protection devices are all manually placed by professional operators, which cannot achieve unmanned and fully automated boarding, and is not conducive to promoting the construction of smart civil aviation and four types of airports promoted by the Civil Aviation Administration of China. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a safety protection device for a boarding bridge that can automatically extend and retract its lifting platform, improving pick-up efficiency, facilitating unmanned and fully automated pick-up, and increasing the safety distance to reduce the possibility of damage to aircraft doors and boarding bridges.

[0005] According to an embodiment of the present invention, a boarding bridge safety protection device includes: a lifting platform for movably passing through the swing floor of the boarding bridge, having a first state extending upward from the swing floor and a second state being received downward from the swing floor; an elastic member connected to the lifting platform for driving the lifting platform to stabilize in the first state; a clutch drive mechanism capable of being connected to the lifting platform to drive the lifting platform to move to the second state, or disengaged from the lifting platform to allow the elastic member to drive the lifting platform to move to the first state; and a detection device located below the swing floor and electrically connected to the lifting system of the boarding bridge for detecting the position of the lifting platform and transmitting a signal to the lifting system.

[0006] The boarding bridge safety protection device according to an embodiment of the present invention has at least the following features:

[0007] Beneficial effects:

[0008] Before the boarding bridge docks with the aircraft door, a clutch-driven mechanism retracts the lifting platform beneath the swing floor. When the boarding bridge is adjusted until the swing floor is parallel to the aircraft door and at a preset height distance, the aircraft door opens, and the clutch-driven mechanism extends the lifting platform upwards above the swing floor to monitor the relative position between the boarding bridge and the aircraft door. In case of an emergency, the lower edge of the aircraft door pushes the lifting platform downwards to a certain position. The detection device transmits a signal to the boarding bridge's lifting system to control the boarding bridge's emergency descent. The automatic extension and retraction of the lifting platform improves arrival efficiency and facilitates unmanned, fully automated arrival. Furthermore, because the lifting platform can be completely concealed beneath the swing floor, the safe distance for the aircraft door to descend relative to the swing floor is increased, reducing the possibility of damage to the aircraft door and boarding bridge.

[0009] In some embodiments of the present invention, the boarding bridge safety protection device further includes a housing having an upwardly opening cavity extending downward along the upper surface of the swing floor, wherein the lifting platform, the elastic element and the clutch drive mechanism are all located within the cavity, and the lifting platform can extend upward out of the opening of the cavity or be received downward within the cavity.

[0010] In some embodiments of the present invention, the lifting platform is slidably disposed in the cavity in a vertical direction. The clutch drive mechanism includes a linear actuator, a drive rod, and two parallel connecting rods. One end of the connecting rod is rotatably disposed at the bottom of the lifting platform. The two ends of the drive rod are respectively rotatably connected to the other ends of the two connecting rods. The drive rod is parallel to the bottom surface of the lifting platform. The elastic element is connected to the drive rod to drive the lifting platform to slide upward to the first state. The linear actuator is used to drive the drive rod to move along a path parallel to the bottom surface of the lifting platform so that the lifting platform slides downward to the second state.

[0011] In some embodiments of the present invention, the opposite side walls of the lifting platform abut against the opposite two inner side walls of the housing, and a guide wheel is rotatably connected to the upper end of one of the connecting rods at the pivot point of the lifting platform. The guide wheel abuts against the inner side wall of the housing to guide the lifting platform to slide in the up-down direction.

[0012] In some embodiments of the present invention, a connecting rod is provided at both ends of the two side walls of the slide table along its sliding direction, and the slide table, the two connecting rods located on the same side and the lifting platform constitute a parallelogram four-bar linkage.

[0013] In some embodiments of the present invention, the linear actuator includes a lead screw arranged parallel to the drive rod, a motor driving the lead screw to rotate, and a toggle member connected to the lead screw in a transmission manner. The drive rod is connected to a slide table, and the housing is provided with a guide structure for guiding the slide table to slide along the bottom surface parallel to the lifting platform. When the motor drives the lead screw to rotate, the toggle member can push the slide table to move in the direction of compressing the elastic member.

[0014] In some embodiments of the present invention, the guide structure includes a guide rod that extends laterally through the housing, the slide has a through hole for the guide rod to pass through, and the elastic element is a spring that passes through the guide rod, with the two ends of the spring abutting against the inner wall of the slide and the housing, respectively.

[0015] In some embodiments of the present invention, the detection device includes a sensor disposed on the inner wall of the housing and a sensing component disposed on the slide and opposite to the output end of the sensor.

[0016] In some embodiments of the present invention, a through-hole communicating with the cavity is provided on one side wall of the housing, the through-hole being directly opposite the elastic member and the clutch drive mechanism, and a cover plate is detachably installed at the through-hole.

[0017] In some embodiments of the present invention, the surface of the lifting platform is covered with a cushioning sleeve made of a flexible material.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is a schematic diagram of the structure of the boarding bridge safety protection device of the present invention applied to the swing floor of the boarding bridge;

[0021] Figure 2 This is an exploded view of the structure of one embodiment of the boarding bridge safety protection device of the present invention;

[0022] Figure 3 This is a schematic diagram of the lifting platform in a second state according to an embodiment of the boarding bridge safety protection device of the present invention.

[0023] Figure 4 This is a schematic diagram of the lifting platform in a first state according to an embodiment of the boarding bridge safety protection device of the present invention.

[0024] Figure 5 This is a schematic diagram of the structure of the lifting platform of one embodiment of the boarding bridge safety protection device of the present invention when it is pressed down by the aircraft cabin door. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0026] In the description of this invention, it should be understood that the orientation descriptions, such as the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer", indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0027] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] See Figures 1 to 5The safety protection device for a boarding bridge of the present invention includes: a lifting platform 100, which is movably mounted on the swing floor 10 of the boarding bridge and has a first state extending upward from the swing floor 10 and a second state being received downward from the swing floor 10; an elastic member 200, connected to the lifting platform 100, for driving the lifting platform 100 to stabilize in the first state; a clutch drive mechanism 300, which can be connected to the lifting platform 100 to drive the lifting platform 100 to move to the second state, or separated from the lifting platform 100 so that the elastic member 200 drives the lifting platform 100 to move to the first state; and a detection device 400, located below the swing floor 10 and electrically connected to the lifting system of the boarding bridge, for detecting the position of the lifting platform 100 and transmitting a signal to the lifting system.

[0030] Before the boarding bridge docks with the aircraft door, see Figure 3 The clutch drive mechanism 300 drives the lifting platform 100 to be housed below the swing floor 10, thereby facilitating the adjustment of the swing floor 10 of the boarding bridge to be parallel to the aircraft door, and ensuring that the swing floor 10 and the lower edge of the aircraft door meet a preset height distance. In this state, the swing floor 10 of the boarding bridge is in the same normal receiving state and does not hinder receiving passengers; see also Figure 1 and Figure 4 Once the relative position between the swing floor 10 of the boarding bridge and the aircraft door is adjusted to the correct position, the aircraft door opens. A sensor switch or other switch can control the clutch drive mechanism 300 to extend the lifting platform 100 upwards beyond the swing floor 10, thereby monitoring the relative position between the boarding bridge and the aircraft door; see also Figure 5 In the event of an accident such as a tire blowout or failure of the automatic leveling mechanism of the boarding bridge, the aircraft door descends relative to the swing floor 10. The lower edge of the aircraft door can then push the lifting platform 100 downward. When the lifting platform 100 moves downward to a preset position that can trigger the detection device 400, the detection device 400 transmits a signal to the lifting system of the boarding bridge to control the emergency descent of the boarding bridge, thereby avoiding a rigid collision between the aircraft door and the swing floor 10. The automatic extension and retraction function of the lifting platform 100 improves the efficiency of receiving passengers and is conducive to realizing unmanned and fully automated passenger reception.

[0031] Furthermore, it should be noted that traditional safety boots are placed on the upper surface of the swing floor 10, located below the aircraft door. In order to ensure that the height difference between the aircraft door and the swing floor 10 meets the usage requirements, the lifting platform 100 of the traditional safety boot can only descend a relatively small distance. However, the lifting platform 100 of the present invention can be completely housed below the swing floor 10 or the upper surface of the lifting platform 100 is flush with the upper surface of the swing floor 10, which increases the safe distance at which the aircraft door can descend relative to the swing floor 10, and helps to reduce the possibility of damaging the aircraft door and boarding bridge.

[0032] See Figure 2 , Figure 4 In some embodiments of the present invention, the boarding bridge safety protection device further includes a housing 500, which has an upward-facing cavity 510 extending downward along the upper surface of the swing floor 10. The lifting platform 100, the elastic element 200, and the clutch drive mechanism 300 are all located within the cavity 510. The lifting platform 100 can extend upward from the opening of the cavity 510 or be received downward within the cavity 510. The housing 500 provides accommodating space for the lifting platform 100, the elastic element 200, and the clutch drive mechanism 300, thereby achieving a protective effect. Compared to assembling each component individually under the swing floor 10, it is simpler to first assemble the lifting platform 100, the elastic element 200, and the clutch drive mechanism 300 within the cavity 510 of the housing 500, and then install the boarding bridge safety protection device on the swing floor 10. Specifically, a notch matching the outer periphery of the housing 500 is made in the swing floor 10, and a flange plate that can rest against the outer periphery of the notch is provided on the upper edge of the housing 500. The flange plate is fixed to the swing floor 10 by screws.

[0033] See Figure 3 and Figure 4 In some embodiments of the present invention, the lifting platform 100 is slidably disposed in the cavity 510 in the vertical direction. The clutch drive mechanism 300 includes a linear actuator 310, a drive rod 320, and two parallel connecting rods 330. One end of the connecting rod 330 is rotatably disposed at the bottom of the lifting platform 100. The two ends of the drive rod 320 are respectively rotatably connected to the other ends of the two connecting rods 330. The drive rod 320 is parallel to the bottom surface of the lifting platform 100. The elastic element 200 is connected to the drive rod 320 to drive the lifting platform 100 to slide upward to the first state. The linear actuator 310 is used to drive the drive rod 320 to move along the bottom surface of the lifting platform 100 so that the lifting platform 100 slides downward to the second state. It is understandable that the drive rod 320, the two connecting rods 330, and the lifting platform 100 together form a parallelogram four-bar linkage. Since the movement of the lifting platform 100 is limited to lifting and sliding, when the linear actuator 310 drives the drive rod 320 to move along its length to compress the elastic element 200, the drive rod 320 can move the lifting platform 100 down through the two connecting rods 330, so that the lifting platform 100 is in the second state when not in use. When the linear actuator 310 drives the drive rod 320 to move along its length to release the elastic element 200, the elastic element 200 drives the drive rod 320 to move so as to move the lifting platform 100 up through the two connecting rods 330.

[0034] Additionally, it should be noted that the four-bar linkage formed by the drive rod 320, the two connecting rods 330, and the lifting platform 100 provides stable support for the lifting platform 100. Of course, it is understood that in other embodiments, the clutch drive mechanism 300 can be replaced by an electric push rod with its output end pointing vertically downwards, or the electric push rod can be used to drive the cross arm downwards to move the lifting platform 100 downwards. However, compared to these two methods, the output end of the linear actuator 310 of this invention is arranged laterally, which helps to reduce the depth of the cavity 510 and improve the structural compactness of the boarding bridge safety protection device.

[0035] See Figure 3 and Figure 4 In some embodiments of the present invention, the opposite side walls of the lifting platform 100 abut against the opposite inner side walls of the housing 500, thereby restricting the lifting platform 100 to slide only up and down along the cavity wall of the cavity 510. A guide wheel 600 is rotatably connected to the upper end of a connecting rod 330 at its pivot point with the lifting platform 100. The guide wheel 600 abuts against the inner side wall of the housing 500 to guide the lifting platform 100 to slide in the up-down direction. The guide wheel 600 can roll relative to the inner side wall of the housing 500, reducing guiding friction. When the drive rod 320 moves in the horizontal direction, the guide wheel 600 assists the lifting platform 100 in guiding the swing direction of the connecting rod 330.

[0036] See Figure 2 In some embodiments of the present invention, a connecting rod 330 is disposed at both ends of the two side walls of the slide 321 along its sliding direction. The slide 321, the two connecting rods 330 located on the same side, and the lifting platform 100 constitute a parallelogram four-bar linkage. That is, a total of four connecting rods 330 are connected between the slide 321 and the lifting platform 100, forming two parallel parallelogram four-bar linkages. The upper ends of the four connecting rods 330 are distributed at the four corners of a rectangle, which improves the supporting effect of the connecting rods 330 on the lifting platform 100 and avoids the aircraft cabin door pressing down on the lifting platform 100 or the lifting platform 100 tilting during its descent.

[0037] See Figure 3 and Figure 4In some embodiments of the present invention, the linear actuator 310 includes a lead screw 311 arranged parallel to the drive rod 320, a motor 312 driving the lead screw 311 to rotate, and a toggle member 313 connected to the lead screw 311 in transmission. The drive rod 320 is connected to a slide table 321. The housing 500 is provided with a guide structure for guiding the slide table 321 to slide along the bottom surface parallel to the lifting platform 100. When the motor 312 drives the lead screw 311 to rotate, the toggle member 313 can push the slide table 321 to move in the direction of compressing the elastic member 200. When the lifting platform 100 needs to be housed under the swing floor 10, the motor 312 rotates in the first clockwise direction to drive the lead screw 311 to rotate. The lead screw 311 is linked to the actuating member 313 to move horizontally. The actuating member 313 pushes the slide 321 to move along the direction of compressing the elastic member 200, thereby using the connecting rod 330 to drive the lifting platform 100 to descend. When the motor 312 rotates in the second clockwise direction to drive the lead screw 311 to rotate, the lead screw 311 is linked to the actuating member 313 to move back to its original position. The actuating member 313 moves in the direction of releasing the elastic member 200. At this time, the slide 321 moves back to its original position under the action of the elastic member 200, thereby using the connecting rod 330 to drive the lifting platform 100 to rise.

[0038] See Figure 3 and Figure 4 In some embodiments of the present invention, the guide structure includes a guide rod 700 that extends laterally through the housing 500, a slide 321 having a through hole for the guide rod 700 to pass through, and an elastic element 200 being a spring passing through the guide rod 700, with both ends of the spring abutting against the inner walls of the slide 321 and the housing 500, respectively. Preferably, a linear bearing is provided between the guide rod 700 and the through hole of the slide 321, which facilitates the smooth reciprocating sliding of the slide 321 along the length direction of the guide rod 700. When the linear actuator 310 drives the actuating element 313 to move against the side of the slide 321, the spring is compressed, and the movement of the slide 321 causes the connecting rod 330 to swing downward, thereby causing the lifting platform 100 to descend to the second state to be housed below or level with the swing floor 10.

[0039] See Figure 4 and Figure 5In some embodiments of the present invention, the detection device 400 includes a sensor 410 disposed on the inner wall of the housing 500 and a sensing component 420 disposed on the slide 321 and opposite to the output end of the sensor 410. In this embodiment, the sensor 410 is a proximity sensor. When an accident occurs, such as a tire blowout or failure of the automatic leveling mechanism of the boarding bridge, the lower edge of the aircraft door pushes the lifting platform 100 downward. When the lifting platform 100 moves downward, it is linked by the linkage 330 to move the slide 321 away from the proximity sensor. When the distance between the sensing component 420 and the proximity sensor reaches a preset value, the aircraft door is about to collide with the swing floor 10. The detection device 400 transmits a signal to the lifting system of the boarding bridge to control the boarding bridge to descend urgently, thereby avoiding a rigid collision between the aircraft door and the swing floor 10. Of course, in other embodiments, the sensor 410 can also be replaced by a photoelectric sensor located in the housing 500. When the slide 321 slides to a preset position, the photoelectric sensor can be triggered, and then the triggered signal is transmitted to the lifting system of the boarding bridge to control the emergency descent of the boarding bridge.

[0040] Additionally, it should be noted that after the boarding bridge is completed, the lifting platform 100 is housed below the swing floor 10 under the action of the clutch drive mechanism 300. At this time, the boarding bridge is in the retracted state. Even if the slide 321 is in the preset position that can trigger the sensor 410, the lifting system of the boarding bridge will not perform an emergency descent operation.

[0041] See Figure 2 In some embodiments of the present invention, for the convenience of assembly or inspection and maintenance, a through-hole 520 communicating with the cavity 510 is provided on one side wall of the housing 500. The through-hole 520 is directly opposite the elastic member 200 and the clutch drive mechanism 300. A cover plate 530 is detachably installed at the through-hole 520.

[0042] See Figure 1 and Figure 4 In some embodiments of the present invention, in order to reduce the damage to the aircraft door when it comes into contact with the elevator platform 100, the surface of the elevator platform 100 is covered with a buffer sleeve 800 made of flexible material.

[0043] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A safety protection device for a boarding bridge, characterized in that include: The lifting platform (100) is movably mounted on the swing floor (10) of the boarding bridge, and has a first state of extending upward from the swing floor (10) and a second state of being received downward from the swing floor (10). An elastic element (200) is connected to the lifting platform (100) and is used to drive the lifting platform (100) to stabilize in the first state; The clutch drive mechanism (300) can be connected to the lifting platform (100) to drive the lifting platform (100) to move to the second state, or be separated from the lifting platform (100) so that the elastic element (200) drives the lifting platform (100) to move to the first state; The detection device (400), located below the swing floor (10) and electrically connected to the lifting system of the boarding bridge, is used to detect the position of the lifting platform (100) and transmit the signal to the lifting system; It also includes a housing (500) having an upward-opening cavity (510) extending downward along the upper surface of the swing floor (10). The lifting platform (100), the elastic element (200), and the clutch drive mechanism (300) are all located within the cavity (510). The lifting platform (100) can extend upward from the opening of the cavity (510) or be received downward within the cavity (510). The clutch drive mechanism (300) is slidably disposed in the cavity (510) in the downward direction. It includes a linear actuator (310), a drive rod (320), and two parallel connecting rods (330). One end of the connecting rod (330) is rotatably disposed at the bottom of the lifting platform (100). The two ends of the drive rod (320) are rotatably connected to the other ends of the two connecting rods (330). The drive rod (320) is parallel to the bottom surface of the lifting platform (100). The elastic element (2... 00) is connected to the drive rod (320) to drive the lifting platform (100) to slide upward to the first state, and the linear actuator (310) is used to drive the drive rod (320) to move along the bottom surface parallel to the lifting platform (100) so that the lifting platform (100) slides downward to the second state; the linear actuator (310) includes a lead screw (311) arranged parallel to the drive rod (320) and a motor that drives the lead screw (311) to rotate. 312) and a lever (313) connected to the lead screw (311) for transmission. The drive rod (320) is connected to a slide (321). The housing (500) is provided with a guide structure for guiding the slide (321) to slide along the bottom surface parallel to the lifting platform (100). When the motor (312) drives the lead screw (311) to rotate, the lever (313) can push the slide (321) to move in the direction of compressing the elastic member (200).

2. The boarding bridge safety protection device according to claim 1, characterized in that: The opposite side walls of the lifting platform (100) abut against the opposite two inner side walls of the housing (500). The upper end of one of the connecting rods (330) is rotatably connected to the pivot of the lifting platform (100) with a guide wheel (600). The guide wheel (600) abuts against the inner side wall of the housing (500) to guide the lifting platform (100) to slide in the up and down direction.

3. The boarding bridge safety protection device according to claim 1, characterized in that: The slide (321) has a connecting rod (330) at both ends of its two side walls along its sliding direction. The slide (321), the two connecting rods (330) on the same side and the lifting platform (100) form a parallelogram four-bar linkage.

4. The boarding bridge safety protection device according to claim 1, characterized in that: The guide structure includes a guide rod (700) that passes laterally through the housing (500), the slide (321) has a through hole for the guide rod (700) to pass through, and the elastic element (200) is a spring that passes through the guide rod (700), with the two ends of the spring abutting against the inner wall of the slide (321) and the housing (500) respectively.

5. The boarding bridge safety protection device according to claim 1, characterized in that: The detection device (400) includes a sensor (410) disposed on the inner wall of the housing (500) and a sensing component (420) disposed on the slide (321) and opposite to the output end of the sensor (410).

6. The boarding bridge safety protection device according to claim 1, characterized in that: The housing (500) has a through-hole (520) on one side wall that communicates with the cavity (510). The through-hole (520) is directly opposite the elastic element (200) and the clutch drive mechanism (300). A cover plate (530) is detachably installed at the through-hole (520).

7. The boarding bridge safety protection device according to claim 1, characterized in that: The surface of the lifting platform (100) is covered with a buffer sleeve (800) made of flexible material.

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