A concealed automatic door opening and closing device

Abstract

The application provides a hidden automatic door opening and closing device, which comprises two warehouse door guide plates (16), each of which is provided with a guide groove (31); two warehouse door drive guide blocks (26), each of which is provided with a first guide groove (34) and a second guide groove (35), and each of which is connected with a warehouse door guide plate (16) through two warehouse door guide shafts (27); and a warehouse door (12) which is rotatably connected with the warehouse door guide shaft (27), and the warehouse door drive guide block (26) is configured to be movable relative to the warehouse door guide plate (16) in the horizontal direction. The hidden automatic door opening and closing device of the application does not occupy the upper space when the warehouse door is opened, and the opening process of the warehouse door is smoother. After the warehouse door is closed, it is lifted to form a closed cavity with the surrounding structure, prevents dust from entering and has a heat preservation effect.

Description

Technical Field

[0001] This invention relates to the field of bioengineering or medical device technology, specifically a concealed automatic door opening and closing device, particularly a concealed automatic door opening and closing device for a PCR instrument. Background Technology

[0002] PCR instruments are equipped with a door that allows sample plates to be loaded and unloaded when open, and is closed during the PCR reaction. Existing doors typically employ a top-hinged design, using gears to swing the door outwards and open. This top-hinged design occupies considerable height space, has a plain appearance, and the door cannot be concealed when open, hindering automated operation. Summary of the Invention

[0003] The purpose of this invention is to at least partially overcome the shortcomings of the prior art and provide a novel concealed automatic door opening and closing device.

[0004] Another objective of this invention is to provide a concealed automatic door opening and closing device that does not occupy the space above the PCR instrument.

[0005] The present invention also aims to provide a concealed automatic door opening and closing device so that the PCR instrument's door does not affect the overall aesthetics when it is open.

[0006] The present invention also aims to provide a concealed automatic door opening and closing device that can efficiently and conveniently realize the opening and closing of the PCR instrument.

[0007] Another objective of this invention is to provide a concealed automatic door opening and closing device, which makes the door more tightly closed.

[0008] To achieve the above-mentioned objectives or one of them, the technical solution of the present invention is as follows:

[0009] A concealed automatic door opening and closing device for a PCR instrument, the door opening and closing device comprising:

[0010] Two door guide plates, each door guide plate is provided with a guide groove, the guide groove is in the shape of a bent zigzag line, and has an end protruding groove at one end and a middle protruding groove in the middle of the guide groove;

[0011] Two door drive guide blocks, each with a first guide groove and a second guide groove, each door drive guide block being connected to a door guide plate via two door guide shafts, wherein one door guide shaft passes through the first guide groove and the guide groove, and the other door guide shaft passes through the second guide groove and the guide groove; and

[0012] A storage door, which is rotatably connected to a storage door guide shaft.

[0013] The door drive guide block is configured to move horizontally relative to the door guide plate, allowing the door guide shaft to achieve door closing, door downward movement, door forward movement, door flipping, and door full opening under the guidance of the guide groove, the first guide groove, and the second guide groove.

[0014] According to a preferred embodiment of the present invention, the door opening and closing device further includes:

[0015] drive;

[0016] The transmission belt is driven by a driver.

[0017] The tensioner pulley is located on the transmission path of the drive belt;

[0018] Two guide pulleys are used, and a drive belt is wound around the two guide pulleys. The axes of rotation of the two guide pulleys are located on the same horizontal plane, so that the drive belt between the two guide pulleys remains horizontal.

[0019] The door drive guide block is fixedly connected to the transmission belt between two guide wheels.

[0020] According to a preferred embodiment of the present invention, the door opening and closing device further includes:

[0021] A synchronous drive assembly is attached to two drive belts to drive them synchronously.

[0022] Drive wheel, connected to the drive unit for transmission;

[0023] The driven wheel is mounted on the synchronous transmission assembly and meshes with the drive wheel.

[0024] According to a preferred embodiment of the present invention, the door opening and closing device further includes an opening sensor, a closing sensor, and a triggering element. The opening sensor and the closing sensor are respectively disposed at both ends of a door guide plate; the triggering element is disposed on the door drive guide block.

[0025] According to a preferred embodiment of the present invention, both the first guide groove and the second guide groove include a longitudinally elongated guide groove segment and a bent segment connected to the guide groove segment, and the first guide groove and the second guide groove have different shapes.

[0026] According to a preferred embodiment of the present invention, the door opening and closing device further includes a door support plate and a door support block. The door support plate is disposed on the lower side of the door and fixedly connected to the door. The door support block is disposed on both sides of the door support plate. The door guide shaft is pivotally connected to the door support block.

[0027] According to a preferred embodiment of the present invention, a front fixing plate and a rear fixing plate are fixedly connected to both ends of the door guide plate, and the two door guide plates, the front fixing plate and the rear fixing plate form a frame.

[0028] According to a preferred embodiment of the present invention, the door opening and closing device further includes:

[0029] Side slide plate fixing screws are fixedly installed on the lower side of the end of the compartment door to fix the side slide plate and the compartment door push plate;

[0030] Two side slides for the cargo door, roughly T-shaped, are provided with a slide groove and a spring fixing screw. The side slides for the cargo door are configured to slide on the cargo door.

[0031] The spring fixing screw is fixed to the side slide plate of the compartment door, so that the side slide plate of the compartment door can slide relative to the compartment door;

[0032] The side sliding spring of the warehouse door is fixed at both ends to the spring fixing screws;

[0033] The door push plate is configured to slide on the door, located between the two door side slides.

[0034] In this configuration, under the action of the side sliding spring of the cargo door, the two side sliding plates of the cargo door tend to move closer to each other, and when the cargo door push plate slides towards the front of the cargo door, the cargo door push plate pushes the two side sliding plates of the cargo door away from each other. According to a preferred embodiment of the present invention, the surface of the cargo door push plate that abuts against the cargo door side sliding plate is an inclined surface.

[0035] According to a preferred embodiment of the present invention, a transmission tensioning element is provided on the transmission belt.

[0036] The concealed automatic door opening and closing device provided by this invention adopts an embedded structure. When the PCR instrument's door is opened, it is concealed inside the instrument, not occupying upper height space. It features a novel, unique, and aesthetically pleasing design, effectively solving the problems associated with upward-opening door structures. Furthermore, the door opening process is smoother, more automated, and more efficient and convenient. Additionally, the door's end incorporates a side sliding plate and a push plate, which adaptively compensate for gaps at the door's end, resulting in a tighter seal. Attached Figure Description

[0037] Figure 1 The four states of the concealed automatic door opening and closing device according to an embodiment of the present invention are shown;

[0038] Figure 2 A perspective view of a PCR instrument with a concealed automatic door opening and closing device according to an embodiment of the present invention, wherein the outer casing has been removed;

[0039] Figure 3 A perspective view of a PCR instrument with a concealed automatic door opening and closing device according to an embodiment of the present invention, wherein the outer casing and the door are removed;

[0040] Figure 4 A perspective view of a concealed automatic door opening and closing device according to an embodiment of the present invention;

[0041] Figure 5 for Figure 2 The side view shows the concealed automatic door opening and closing device in the closed position of the compartment door;

[0042] Figure 6 for Figure 2 A side view showing the concealed automatic door opening and closing device in the lowered position of the compartment door;

[0043] Figure 7 for Figure 2 A side view showing the concealed automatic door opening and closing device in the forward-moving position of the compartment door;

[0044] Figure 8 for Figure 2 A side view showing the concealed automatic door opening and closing device in the open position of the compartment door;

[0045] Figure 9 The rear side of a concealed automatic door opening and closing device according to an embodiment of the present invention is shown;

[0046] Figure 10 This is a bottom view of a concealed automatic door opening and closing device according to an embodiment of the present invention, wherein the compartment door is in a closed state;

[0047] Figure 11 This is a bottom view of a concealed automatic door opening and closing device according to an embodiment of the present invention, wherein the door is in a downward position;

[0048] Figure 12 This is a bottom view of a concealed automatic door opening and closing device according to an embodiment of the present invention, wherein the door is in a forward-moving state;

[0049] Figure 13 This is a bottom view of a concealed automatic door opening and closing device according to an embodiment of the present invention, wherein the compartment door is in the open state;

[0050] Figure 14 An exploded view of a concealed automatic door opening and closing device according to an embodiment of the present invention;

[0051] Figure 15 This is a partial exploded view of a concealed automatic door opening and closing device according to an embodiment of the present invention. Detailed Implementation

[0052] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements. Furthermore, in the following detailed description, numerous specific details are set forth for ease of explanation to provide a thorough understanding of the embodiments disclosed herein. However, it will be apparent that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and apparatuses are illustrated to simplify the drawings.

[0053] The concealed automatic door opening and closing device of the present invention is used in a PCR instrument. Figure 1 This PCR instrument is shown, which includes a shell 11, a front shell 13, a rear shell 22, and a substrate 14. Figure 5 The PCR instrument's housing consists of an outer shell 11, a front shell 13, a rear shell 22, and a base 14. The compartment opening is located on the upper side of the outer shell 11. A concealed automatic door opening / closing device includes a compartment door 12, which works in conjunction with the outer shell 11 to open and close the compartment opening. The entire automatic door opening / closing device is located inside the housing. Figure 2 As shown, it is supported and fixed inside the PCR instrument by support element 15.

[0054] As shown in the figure, the door opening and closing device includes two door guide plates 16, two door drive guide blocks 26, and a door 12. The two door guide plates 16 are symmetrically arranged inside the housing 11 and are fixed. Each door guide plate 16 has a guide groove 31, which is a bent zigzag shape. One end of the guide groove 31 has an upper protrusion 32, and the middle of the guide groove 31 has an upper protrusion 33. The guide groove 31 is generally composed of two straight grooves that form an angle of 100-150 degrees at their junction. Each door drive guide block 26 has a first guide groove 34 and a second guide groove 35. Each door drive guide block 26 is connected to one door guide plate 16 via two door guide shafts 27, which pass through the drive guide block and the door guide plate and are fixed in place. On the door support plate (described later), one door guide shaft 27 passes through the first guide groove 34 and the guide groove 31, and another door guide shaft 27 passes through the second guide groove 35 and the guide groove 31; the door 12 is rotatably connected to the door guide shaft 27, and the door is fixed on the door support plate. Due to the constraint of the guide shaft position by the shape of the track, the door moves obliquely downward. The door drive guide block 26 is configured to move horizontally relative to the door guide plate 16, so that the door guide shaft 27, guided by the guide groove 31, the first guide groove 34 and the second guide groove 35, allows the door 12 to close, move downward, move forward, flip, and fully open.

[0055] Here, both the first guide groove 34 and the second guide groove 35 include a longitudinally elongated guide groove section and a bent section connected to the guide groove section, forming an approximate L-shape. The shapes of the first guide groove 34 and the second guide groove 35 are different. The end upper protrusion 32 and the middle upper protrusion 33 correspond to the highest positions of the two door guide shafts 27. That is, when the two door guide shafts 27 are within the end upper protrusion 32 and the middle upper protrusion 33, the vertical height of the door is the highest, corresponding to the closed state of the door. The bent sections of the first guide groove 34 and the second guide groove 35 are at the same vertical height as the end upper protrusion 32 and the middle upper protrusion 33. Thus, when the door is closed, one door guide shaft 27 is simultaneously located within the end upper protrusion 32 and the bent section of the first guide groove 34, and the other door guide shaft 27 is simultaneously located within the middle upper protrusion 33 and the bent section of the second guide groove 35.

[0056] The door opening and closing device further includes: a driver 17, which can be a motor, fixed by a driver fixing member 43, which is mounted on a front fixing plate 59 (described later); a transmission belt 20 driven by the driver 17; a tensioning pulley 19 disposed on the transmission path of the transmission belt 20; and two guide pulleys 21 around which the transmission belt 20 is wound, with the rotation axes of the two guide pulleys 21 located on the same horizontal plane, so that the transmission belt 20 between the two guide pulleys 21 remains horizontal. The door drive guide block 26 is fixedly connected to the transmission belt 20 between the two guide pulleys 21 by a transmission fixing member 36, which includes an L-shaped plate and a clamping piece. One arm of the L-shaped plate is fixed to the door drive guide block 26, and the other arm of the L-shaped plate is connected to the clamping piece to hold the transmission belt. A transmission tensioning element 66 is provided on the transmission belt 20. The guide wheel 21 is fixed to the door guide plate 16 via the guide drive shaft 64, and bushings 63 are fitted on both sides of the guide wheel 21 on the guide drive shaft 64. The tension wheel 19 is fixed to the synchronous shaft fixing member 62 via the tension shaft 65, and bushings are fitted on both sides of the tension shaft 65 and the tension wheel 19.

[0057] The door opening and closing device further includes: a synchronous transmission assembly 18, attached to two transmission belts 20 to drive the two transmission belts 20 synchronously; a drive wheel 44, connected to the driver 17; and a driven wheel 45, disposed on the synchronous transmission assembly 18 and meshing with the drive wheel 44. In this way, one driver 17 can drive two transmission belts 20 and achieve synchronous movement of the transmission belts. The synchronous transmission assembly 18 includes a synchronous shaft 61, which is rotatably fixed to two synchronous shaft fixing members 62 by bearings 60. The two synchronous shaft fixing members 62 are respectively fixed to the outer side of the door guide plate 16, and the driven wheel 45 is disposed on the synchronous shaft 61.

[0058] According to a preferred embodiment of the present invention, the door opening and closing device further includes an opening sensor 23, a closing sensor 24, and a triggering element 25. The opening sensor 23 and the closing sensor 24 are respectively disposed at both ends of a door guide plate 16; the triggering element 25 is disposed on the door drive guide block 26. The opening sensor 23 and the closing sensor 24 of the present invention can be photoelectric sensors, microswitches, or Hall effect sensors.

[0059] Here, the door opening and closing device also includes a door support plate 41 and a door support block 67. The door support plate 41 is disposed on the lower side of the door 12 and fixedly connected to the door 12. The door support block 67 is disposed on both sides of the door support plate 41. The door guide shaft 27 is pivotally connected to the door support block 67. A front fixing plate 59 and a rear fixing plate 42 are fixedly connected to both ends of the door guide plate 16, and the two door guide plates 16, the front fixing plate 59, and the rear fixing plate 42 form a frame.

[0060] The following describes several states of the compartment door: When the compartment door is open or closed, the drive unit 17 drives the synchronous transmission assembly 18 to move. Under the action of the tension wheel 19 and the guide wheel 21, the synchronous transmission assembly 18 drives the compartment door drive guide block 26 along the transmission belt 20. Figure 5 Move left and right in the middle.

[0061] Door downward movement state: When the door is closed, the door is driven by the driver 17, which drives the transmission belts 20 on both sides to move simultaneously through the synchronous transmission assembly 18. The transmission belts 20 then drive the door drive guide block 26 to move to the right. The door moves downward and to the right under the combined action of the guide groove of the door drive guide block 26 and the guide groove of the door guide plate 16.

[0062] Rightward movement of the door: After the door has finished moving downward, it moves to the right under the combined action of the guide groove of the door guide plate 16 and the guide groove of the door drive guide block 26 to continue opening the door.

[0063] Door Opening State: After the door completes its rightward movement, it moves downward and to the right under the combined action of the guide groove of the door guide plate 16 and the guide groove of the door drive guide block 26. When the door opening sensor 23 is triggered, the door opens. At this time, the door is retracted into the instrument from its closed state.

[0064] Closed position of the compartment door: When the compartment door is in the open position, the drive unit 17 drives the synchronous transmission assembly 18 to move the two transmission belts 20 simultaneously. The transmission belts 20 then drive the compartment door drive guide block 26 to move to the left. Under the combined action of the guide groove of the compartment door drive guide block 26 and the guide groove of the compartment door guide plate 16, the compartment door moves upward and to the left. When the closing sensor 24 is triggered, the compartment door is closed. The compartment door is self-locking after closing and cannot be opened from the outside, which can effectively protect the internal structure.

[0065] In a preferred embodiment of the present invention, the door opening and closing device further includes: side slide plate fixing screws 51, which are fixedly disposed on the lower side of the end of the door 12 to fix the door side slide plate 52 and the door push plate 53; the two door side slide plates 52 are approximately T-shaped, as shown in the figure. Figure 15 As shown, each door side slide plate 52 is provided with a spring fixing screw 55. Specifically, the door side slide plate 52 has a spring fixing screw hole 69, and the spring fixing screw 55 is screwed into the spring fixing screw hole 69, so that the door side slide plate 52 can slide relative to the door 12; a door side sliding spring 56, the two ends of which are respectively fixed to the spring fixing screw 55; a door push plate 53 is configured to be slidably disposed on the door 12, located between the two door side slide plates 52. Under the action of the door side sliding spring 56, the two door side slide plates 52 tend to move closer to each other, and when the door push plate 53 slides towards the front of the door 12, the door push plate 53 pushes the two door side slide plates 52 away from each other.

[0066] Specifically, the surfaces of the door push plate 53 and the door side slide plate 52 that abut against each other are inclined surfaces 68.

[0067] With the above structure, when the door 12 is closed, as the door 12 moves to a position close to the rear fixing plate 42, the door push plate 53 contacts the rear fixing plate 42. As the door 12 continues to move backward, the door push plate 53 is pushed forward along the door 12 by the rear fixing plate 42. This causes the door push plate 53 to retract inward. As the door push plate 53 retracts, since the inclined surface 68 of the door push plate 53 and the inclined surface 68 of the door side sliding plate 52 are always in contact, the door side sliding plate 52 is pushed outward, overcoming the tension of the door side sliding spring 56. Thus, the two door side sliding plates 52 push outward, sealing the edge where the door 12 contacts the outer casing 11. Therefore, when the door is closed, the door push plate 53 retracts inward, while the door side sliding plate 52 extends outward; when the door is open, the opposite occurs: the door push plate 53 extends outward, while the door side sliding plate 52 retracts inward. Figure 11 This process is illustrated in [reference]. Figure 11 The arrow.

[0068] The concealed automatic door opening and closing device provided by this invention adopts an embedded structure. When the PCR instrument's door is opened, it is concealed inside the instrument, not occupying upper height space. It features a novel, unique, and aesthetically pleasing design, effectively solving the problems associated with upward-opening door structures. Furthermore, the door opening process is smoother, more automated, and more efficient and convenient. Additionally, the door's end incorporates a side sliding plate and a push plate, which adaptively compensate for gaps at the door's end, resulting in a tighter seal.

[0069] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that variations may be made to these embodiments without departing from the principles and spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents.

[0070] List of reference numerals in the attached diagram:

[0071] 11. Shell

[0072] 12 warehouse doors

[0073] 13 front shell

[0074] 14 base

[0075] 15 Supporting Components

[0076] 16-compartment door guide plate

[0077] 17 drives

[0078] 18 Synchronous Drive Components

[0079] 19 tensioners

[0080] 20 transmission belt

[0081] 21 guide wheels

[0082] 22 back cover

[0083] 23 Door opening sensor

[0084] 24-hour door closing sensor

[0085] 25 Induction trigger elements

[0086] 26-compartment door drive guide block

[0087] 27. Door guide shaft

[0088] 31 guide groove

[0089] 32 End Upper Protrusion Groove

[0090] 33 Middle Upper Protrusion Slot

[0091] 34 First guide groove

[0092] 35 Second guide groove

[0093] 36 Transmission Fixing Components

[0094] 41. Warehouse door support plate

[0095] 42 rear fixing plate

[0096] 43 Driver Fixture

[0097] 44 drive wheels

[0098] 45 driven wheel

[0099] 51 Side Slide Fixing Screws

[0100] 52 Warehouse Door Side Slide

[0101] 53 Warehouse Door Push Panel

[0102] 54 grooves

[0103] 55 Spring Fixing Screw

[0104] 56. Warehouse door side sliding spring

[0105] 59 front fixing plate

[0106] 60 bearing

[0107] 61 Synchronous Shaft

[0108] 62 Synchronous Shaft Fixture

[0109] 63 bushing

[0110] 64 guide drive shaft

[0111] 65 tensioning shafts

[0112] 66 Transmission tensioning element

[0113] 67 Warehouse Door Support Block

[0114] 68 inclined plane

[0115] 69 Spring fixing screw hole.

Claims

1. A concealed automatic door opening and closing device for a PCR instrument, characterized in that, The door opening and closing device includes: Two door guide plates (16), each door guide plate (16) is provided with a guide groove (31), the guide groove (31) is in the shape of a bent zigzag line, and has an end upper protrusion groove (32) at one end of the guide groove (31) and a middle upper protrusion groove (33) in the middle of the guide groove (31). Two door drive guide blocks (26), each door drive guide block (26) is provided with a first guide groove (34) and a second guide groove (35), each door drive guide block (26) is connected to a door guide plate (16) through two door guide shafts (27), wherein one door guide shaft (27) passes through the first guide groove (34) and the guide groove (31), and the other door guide shaft (27) passes through the second guide groove (35) and the guide groove (31); and The storage door (12) is rotatably connected to the storage door guide shaft (27). The door drive guide block (26) is configured to move horizontally relative to the door guide plate (16), such that the door guide shaft (27), guided by the guide groove (31), the first guide groove (34), and the second guide groove (35), allows the door (12) to close, move downward, move forward, flip, and fully open. The door opening and closing device also includes: Side slide plate fixing screw (51) is fixedly installed on the lower side of the end of the compartment door (12) to fix the compartment door side slide plate (52) and the compartment door push plate (53). Two side sliding plates (52) for the cargo door are approximately T-shaped and have a groove (54) and a spring-loaded fixing screw (55) on them. The side sliding plates (52) for the cargo door are configured to slide on the cargo door (12). The spring fixing screw (55) is fixed on the side slide plate (52) of the compartment door, so that the side slide plate (52) of the compartment door can slide relative to the compartment door (12); The two ends of the door sliding spring (56) are respectively fixed on the spring fixing screw (55); The door push plate (53) is configured to be slidably mounted on the door (12) and located between the two door side slide plates (52). Under the action of the side sliding spring (56) of the warehouse door, the two side sliding plates (52) of the warehouse door tend to move closer to each other, and when the warehouse door push plate (53) slides towards the front side of the warehouse door (12), the warehouse door push plate (53) pushes the two side sliding plates (52) of the warehouse door to move away from each other.

2. The concealed automatic door opening and closing device according to claim 1, characterized in that, The door opening and closing device also includes: Driver (17); The transmission belt (20) is driven by the driver (17); The tension pulley (19) is set on the transmission path of the transmission belt (20); Two guide wheels (21) are provided, and a transmission belt (20) is wound around the two guide wheels (21). The axes of rotation of the two guide wheels (21) are located on the same horizontal plane, so that the transmission belt (20) between the two guide wheels (21) remains horizontal. The door drive guide block (26) is fixedly connected to the transmission belt (20) between two guide wheels (21).

3. The concealed automatic door opening and closing device according to claim 2, characterized in that, The door opening and closing device also includes: Synchronous drive assembly (18) is attached to two drive belts (20) to drive the two drive belts (20) synchronously. The drive wheel (44) is connected to the drive unit (17) via a transmission. The driven wheel (45) is mounted on the synchronous transmission assembly (18) and meshes with the drive wheel (44).

4. The concealed automatic door opening and closing device according to any one of claims 1-3, characterized in that: The door opening and closing device also includes an opening sensor (23), a closing sensor (24), and a sensing trigger element (25). The opening sensor (23) and the closing sensor (24) are respectively located at both ends of a door guide plate (16); the sensing trigger element (25) is located on the door drive guide block (26).

5. The concealed automatic door opening and closing device according to any one of claims 1-3, characterized in that: The first guide groove (34) and the second guide groove (35) both include a longitudinal guide groove segment and a bent segment connected to the guide groove segment. The first guide groove (34) and the second guide groove (35) have different shapes.

6. The concealed automatic door opening and closing device according to any one of claims 1-3, characterized in that: The door opening and closing device also includes a door support plate (41) and a door support block (67). The door support plate (41) is located on the lower side of the door (12) and is fixedly connected to the door (12). The door support block (67) is located on both sides of the door support plate (41). The door guide shaft (27) is pivotally connected to the door support block (67).

7. The concealed automatic door opening and closing device according to any one of claims 1-3, characterized in that: A front fixing plate (59) and a rear fixing plate (42) are fixedly connected to both ends of the door guide plate (16), and the two door guide plates (16), the front fixing plate (59) and the rear fixing plate (42) form a frame.

8. The concealed automatic door opening and closing device according to claim 1, characterized in that: The surface of the door push plate (53) that abuts against the door side slide plate (52) is an inclined surface (68).

9. The concealed automatic door opening and closing device according to claim 2, characterized in that: A transmission tensioning element (66) is provided on the transmission belt (20).

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