Library reading device capable of being adjusted according to requirements

Abstract

The invention discloses a library reading device capable of being adjusted according to requirements, and relates to the technical field of reading table structures. The device comprises a bottom plate, the upper end face of the bottom plate is fixedly connected with a protection structure, the upper end face of the protection structure is in height connection with a top plate, the upper end face of the bottom plate is provided with a driving structure, an inner cavity of the protection structure is slidably connected with a lifting structure, an inner cavity of a placing structure is provided with an adjusting structure, and the upper end face of the placing structure is symmetrically provided with clamping structures along the center line. The angle adjusting structures are symmetrically arranged at the front end of the lower end of the lifting structure along the center line, the placing structure is installed through the lifting frame in the inner cavity of the protection structure in the using process, and then the angle adjusting structures are installed and placed through the lifting plate; in the use process, the adjusting structure and the clamping structure are installed and placed, then books are placed through the placing plate, the height of the book placing platform is adjusted in the use process, and therefore people can use the device conveniently.

Description

Technical Field

[0001] The invention relates to the technical field of reading table structures, in particular to a library reading device which can be adjusted according to needs. Background Art

[0002] Libraries or archives, as institutions that collect books and archives, are important platforms for people to borrow and refer to. Currently, there are a large number of people in libraries who read books and consult scientific research and learning materials. These researchers need to record, archive, compare and calculate the useful text in the books and materials. This requires a relatively closed and isolated space for thinking and research, isolating the interference of external noise and people walking around, and some scientific research data need to be kept confidential, so a reading compartment with a certain degree of privacy will be used.

[0003] The existing reading desk is fixed and cannot adapt to the use of people of different heights. The desktop is an integrated design and cannot be adjusted in angle, so the comfort of the person is affected when reading.

[0004] Therefore, the existing library reading device that can be adjusted according to demand cannot meet the needs in actual use, so there is an urgent need for improved technology in the market to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a library reading device that can be adjusted according to needs, and through the setting, the problems raised in the above background technology are solved.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0007] The present invention is a library reading device that can be adjusted according to needs, comprising a bottom plate, an upper end surface of the bottom plate is fixedly connected to a protective structure, an upper end surface of the protective structure is highly connected to a top plate, a driving structure is arranged on the upper end surface of the bottom plate, a lifting structure is slidably connected to an inner cavity of the protective structure, a placement structure is rotatably connected to the inner cavity of the lifting structure, an adjustment structure is arranged in the inner cavity of the placement structure, a clamping structure is symmetrically arranged on the upper end surface of the placement structure along a center line, and an angle adjustment structure is symmetrically arranged on the front end of the lower end of the lifting structure along the center line.

[0008] Preferably, the protection structure includes a protection frame fixedly connected to the upper end surface of the bottom plate, the inner cavity of the protection frame is symmetrically fixedly connected to the limit rod along the center line, the inner cavity of the protection frame is rotatably connected to a threaded rod between the two protection rods, and the upper end surface of the protection frame is fixedly connected to the top plate.

[0009] Preferably, the driving structure comprises a driving frame fixedly connected to the middle of the upper end surface of the top plate, the inner cavity of the driving frame is rotatably connected to the driving rod, the upper end surface of the top plate is located behind the driving rod and is symmetrically rotatably connected to the worm gear, the upper end surface of the top plate is located in the middle of the inner cavity of the driving frame, and the output end of the driving motor is fixedly connected to the driving rod;

[0010] The outer surface of the driving rod is symmetrically provided with two sections of threads in opposite directions. The threads on the outer surface of the driving rod are meshed with the worm gear. The rotating shaft on the upper end surface of the threaded rod passes through the top plate and is fixedly connected with the worm gear.

[0011] Preferably, the lifting frame includes a lifting plate slidably connected to the inner cavity of the protective frame, the threaded rod passes through the lifting plate and is threadedly connected, a placement groove is opened in the middle of the upper end surface of the lifting plate, the placement groove is rotatably connected to the placement structure through a rotating shaft in the middle of the inner cavity, and the inner cavity of the placement groove is symmetrically fixedly connected to a limited position block along the center point.

[0012] Preferably, the placement structure includes a placement plate rotatably connected to the inner cavity of the placement groove, an adjustment groove is provided in the middle of the upper end surface of the placement plate, a protective plate is symmetrically fixedly connected to the upper end surface of the inner cavity of the adjustment groove along the center line, an adjustment rod is symmetrically rotatably connected to the inner cavity of the adjustment groove along the center line, two sections of threads in opposite directions are symmetrically provided on the outer surface of the adjustment rod, a clamping structure is symmetrically provided in the inner cavity of the adjustment groove, and an adjustment structure is provided on the lower end surface of the inner cavity of the adjustment groove

[0013] Preferably, the adjustment structure includes an adjustment motor fixedly connected to the middle part of the left side of the inner cavity of the adjustment groove, the output end of the adjustment motor is fixedly connected to a driving wheel, the middle part of the outer surfaces of the two adjustment rods are fixedly connected to pulleys, the outer surfaces of the two pulleys are transmission-connected with belts, the inner cavity of the belt is transmission-connected to the outer surface of the driving wheel, and the radius of the outer surface of the driving wheel is larger than the radius of the outer surface of the pulley.

[0014] Preferably, the clamping structure includes a lower placing plate symmetrically and slidingly connected to both sides of the inner cavity of the adjustment groove, an electric telescopic rod is symmetrically fixedly connected to the side of the upper end surface of the lower placing plate away from the center point of the protective frame, the upper end of the electric telescopic rod is fixedly connected to the upper placing plate, and anti-slip belts are fixedly connected to the upper and lower sides between the upper placing plate and the lower placing plate.

[0015] Preferably, the angle adjustment structure includes an adjustment frame fixedly connected to the front part of the lower end face of the lifting plate symmetrically along the center line, the adjustment frame is specifically a quarter-circular ring structure, a mounting frame is fixedly connected between the lifting plate and the side of the adjustment frame close to the center of the circle, limiting grooves are provided on the left and right sides in front of the adjustment frame, and limiting structures matching the limiting grooves are provided on the front parts of the left and right end faces of the placement plate.

[0016] Preferably, the limiting structure includes mounting grooves provided on the front end surfaces of the left and right sides of the placing plate, and a spring is fixedly connected to one end of the inner cavity of the mounting groove away from the protective frame, and a limiting block is fixedly connected to the side of the spring away from the mounting groove, and the limiting block is slidably connected to the inner cavity of the mounting groove, and the outer surface of the limiting block matches the limiting groove.

[0017] The present invention has the following beneficial effects:

[0018] 1. The present invention protects the device during use by means of a protective structure arranged on the upper end surface of the bottom plate, and separates personnel from the surrounding environment through the protective frame, and then limits and fixes the lifting plate when the lifting frame is lifted or lowered by means of a limiting rod, drives and controls the threaded rod during use by means of a driving structure on the upper end surface of the top plate, and then lifts and lowers the lifting frame by means of the threaded rod, installs the placement structure during use by means of the lifting frame in the inner cavity of the protective structure, and then installs and places the angle adjustment structure through the lifting plate, installs and places the adjustment structure and the clamping structure during use by means of the placement structure in the inner cavity of the protective structure, and then places the book through the placement plate, thereby achieving height adjustment of the book placement platform during use, thereby facilitating the use of the device by personnel.

[0019] 2. The present invention drives and adjusts the clamping structure during use through the adjustment structure provided on the placement structure, thereby facilitating the fixation of the opened book; the book is fixed and clamped during use through the clamping structure on the adjustment structure; the inclination angle of the placement plate is conveniently adjusted during use through the angle adjustment structure on the lower end face of the lifting frame, thereby improving the comfort of people when reading; the limiting structure on the placement plate enables the placement plate to engage with the corresponding limiting groove when it is tilted during use, and then the inclination angle of the placement plate is adjusted through the limiting block and the placement plate.

[0020] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the main stereoscopic structure of the present invention;

[0023] Figure 2 It is a schematic diagram of a half-cut three-dimensional structure of the present invention;

[0024] Figure 3This is a schematic diagram of the installation structure of the angle adjustment structure of the present invention;

[0025] Figure 4 For the present invention Figure 2 A schematic diagram of the enlarged structure of the middle A area;

[0026] Figure 5 For the present invention Figure 3 Schematic diagram of the enlarged structure of area B in the middle.

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0028] 1-bottom plate, 2-protection structure, 21-protection frame, 22-limit rod, 23-threaded rod, 3-top plate, 4-driving structure, 41-driving frame, 42-driving rod, 43-worm gear, 44-driving motor, 5-lifting frame, 51-lifting plate, 52-placement slot, 53-limiting block, 6-placement structure, 61-placement plate, 62-adjustment slot, 63-protection plate, 64-adjustment rod, 7-adjustment structure, 71-adjustment motor, 72-drive wheel, 73-belt, 74-pulley, 8-clamping structure, 81-lower clamping plate, 82-electric telescopic rod, 83-upper plate, 84-anti-slip belt, 9-angle adjustment structure, 91-adjustment frame, 92-limiting slot, 93-mounting frame, 94-limiting structure, 941-mounting slot, 942-spring, 943-limiting block. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] See also Figure 1-5 As shown, this embodiment is a library reading device that can be adjusted according to needs, including a base plate 1, the upper end surface of the base plate 1 is fixedly connected to a protective structure 2, the upper end surface of the protective structure 2 is highly connected to a top plate 3, the upper end surface of the base plate 3 is provided with a driving structure 4, the inner cavity of the protective structure 2 is slidably connected to a lifting structure 5, the inner cavity of the lifting structure 5 is rotatably connected to a placement structure 6, the inner cavity of the placement structure 6 is provided with an adjustment structure 7, the upper end surface of the placement structure 6 is symmetrically provided with a clamping structure 8 along the center line, and the lower front end of the lifting structure 5 is symmetrically provided with an angle adjustment structure 9 along the center line.

[0031] Furthermore, the protective structure 2 includes a protective frame 21 fixedly connected to the upper end surface of the base plate 1, the inner cavity of the protective frame 21 is symmetrically fixedly connected to the limiting rod 22 along the center line, the inner cavity of the protective frame 21 is located between the two protective rods 22 and is rotatably connected to a threaded rod 23, and the upper end surface of the protective frame 21 is fixedly connected to the top plate 3. Through the protective structure 2 on the upper end surface of the base plate 1, the device is protected during use, and the personnel and the surrounding environment are separated by the protective frame 21, and then the lifting plate 51 is limited and fixed by the limiting rod 22 when the lifting frame 5 is raised or lowered.

[0032] Furthermore, the driving structure 4 includes a driving frame 41 fixedly connected to the middle part of the upper end surface of the top plate 3, the inner cavity of the driving frame 41 is rotatably connected to a driving rod 42, the upper end surface of the top plate 3 is located at the rear of the driving rod 42 and is symmetrically rotatably connected to a worm gear 43, the upper end surface of the top plate 3 is located at a driving motor 44 in the middle part of the inner cavity of the driving frame 41, and the output end of the driving motor 44 is fixedly connected to the driving rod 42. The driving structure 4 on the upper end surface of the top plate 3 drives and controls the threaded rod 23 during use, and then the lifting frame 5 is lifted and lowered by the threaded rod 23, so that the height of the book placement platform can be adjusted during use, thereby facilitating the use of the device by personnel;

[0033] The outer surface of the driving rod 42 is symmetrically provided with two sections of threads in opposite directions. The threads on the outer surface of the driving rod 42 are meshed with the worm gear 43 . The rotating shaft on the upper end surface of the threaded rod 23 passes through the top plate 3 and is fixedly connected to the worm gear 43 .

[0034] Furthermore, the lifting frame 5 includes a lifting plate 51 slidably connected to the inner cavity of the protective frame 21, the threaded rod 23 passes through the lifting plate 51 and is threadedly connected, a placement groove 52 is opened in the middle of the upper end surface of the lifting plate 51, and the placement groove 52 is rotatably connected to the placement structure 6 through the rotating shaft in the middle of the inner cavity. The inner cavity of the placement groove 52 is symmetrically fixedly connected to the limiting block 53 along the center point. The lifting frame 5 in the inner cavity of the protective structure 5 is used to install the placement structure 6 during use, and then the angle adjustment structure 9 is installed and placed through the lifting plate 51.

[0035] Furthermore, the placement structure 6 includes a placement plate 61 rotatably connected to the inner cavity of the placement groove 52, an adjustment groove 62 is opened in the middle of the upper end surface of the placement plate 61, a protective plate 63 is symmetrically fixedly connected to the upper end surface of the inner cavity of the adjustment groove 62 along the center line, an adjustment rod 64 is symmetrically rotatably connected to the inner cavity of the adjustment groove 62 along the center line, and two sections of threads in opposite directions are symmetrically opened on the outer surface of the adjustment rod 64, the inner cavity of the adjustment groove 62 is symmetrically provided with a clamping structure 8, and the lower end surface of the inner cavity of the adjustment groove 62 is provided with an adjustment structure 7. Through the placement structure 6 in the inner cavity of the protective structure 5, the adjustment structure 7 and the clamping structure 8 are installed and placed during use, and then the book is placed through the placement plate 61.

[0036] Furthermore, the adjustment structure 7 includes an adjustment motor 71 fixedly connected to the middle part of the left side of the inner cavity of the adjustment groove 62, the output end of the adjustment motor 71 is fixedly connected to a driving wheel 72, the middle part of the outer surface of the two adjustment rods 63 are fixedly connected to pulleys 74, the outer surfaces of the two pulleys 74 are transmission-connected with belts 73, the inner cavity of the belt 73 is transmission-connected to the outer surface of the driving wheel 72, the outer surface radius of the driving wheel 72 is larger than the outer surface radius of the pulley 74, and the adjustment structure 7 is placed on the structure 6 to drive and adjust the clamping structure 8 during use, thereby facilitating the fixation of the opened book.

[0037] Furthermore, the clamping structure 8 includes a lower placing plate 81 symmetrically and slidingly connected to both sides of the inner cavity of the adjustment groove 62, and an electric telescopic rod 82 is symmetrically fixedly connected to the side of the upper end surface of the lower placing plate 81 away from the center point of the protective frame 21, and an upper placing plate 83 is fixedly connected to the upper end of the electric telescopic rod 82, and anti-slip belts 84 are fixedly connected to the upper and lower sides between the upper placing plate 83 and the lower placing plate 81.

[0038] Furthermore, the angle adjustment structure 9 includes an adjustment frame 91 which is symmetrically fixedly connected to the front portion of the lower end face of the lifting plate 51 along the center line. The adjustment frame 91 is specifically a quarter-circular ring structure. A mounting frame 93 is fixedly connected between the adjustment frame 91 and the lifting plate 51 on one side close to the center of the circle. Limiting grooves 92 are provided on both the left and right sides of the adjustment frame 91. Limiting structures 94 matching the limiting grooves 92 are provided on the front portions of the left and right sides of the placement plate 62. The book is fixedly clamped during use by the clamping structure 8 on the adjustment structure 7. The inclination angle of the placement plate 61 is conveniently adjusted during use by the angle adjustment structure 9 on the lower end face of the lifting frame 9, thereby improving the comfort of use for personnel when reading.

[0039] Furthermore, the limiting structure 94 includes mounting grooves 941 provided on the front end surfaces of the left and right sides of the placement plate 62, and a spring 942 is fixedly connected to the end of the inner cavity of the mounting groove 941 away from the protective frame 21, and a limiting block 943 is fixedly connected to the side of the spring 942 away from the mounting groove 941, and the limiting block 943 is slidably connected to the inner cavity of the mounting groove 941, and the outer surface of the limiting block 943 matches the limiting groove 92 with each other. Through the limiting structure 94 on the placement plate 61, when the placement plate 61 is tilted during use, it engages with the corresponding limiting groove 92, and then the inclination angle of the placement plate 61 is adjusted through the limiting block 943 and the placement plate 61.

[0040] Working principle:

[0041] During operation, the driving structure 4 is started, so that the output end of the driving motor 44 rotates, so the driving rod 42 rotates, and at this time, the worm gear 43 rotates through the thread on the outer surface of the driving rod 42, so the threaded rod 23 rotates, so that the height of the lifting plate 52 is raised and lowered, and the lifting plate 52 is limited by the limiting rod 22, so that the lifting plate 52 is moved to a suitable height, and the personnel put the book on the upper end surface of the placement plate 61, and the personnel put the two ends of the book between the two lower placement plates 81 and the upper placement plate 84 respectively, and the electric telescopic rod 83 is started at this time, so that the protective belts 84 are close to each other, so as to clamp the book, and the electric telescopic rod 83 is started at this time, so that the protective belts 84 are close to each other, so as to clamp the book. The dynamic adjustment structure 7 causes the output end of the adjustment motor 71 to rotate, so the driving wheel 72 rotates, so the belt 73 rotates, so the pulley 74 rotates, and then the adjustment rod 64 rotates, so that the lower placement plates 81 on both sides move away from each other, thereby opening and fixing the book, and further pushing the placement plate 61 to make the placement plate 61 rotate, so the limit blocks 943 slide against each other, so the spring 942 contracts, thereby causing the placement plate 61 to rotate, and when the appropriate angle is reached, the spring 942 extends, so the limit block 943 extends, thereby engaging with the limit groove 94, thereby limiting and fixing the rotated placement plate 61.

[0042] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0043] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A library reading device that can be adjusted according to needs, comprising a base plate (1), characterized in that; The upper end surface of the bottom plate (1) is fixedly connected to a protective structure (2), the upper end surface of the protective structure (2) is vertically connected to a top plate (3), the upper end surface of the bottom plate (3) is provided with a driving structure (4), the inner cavity of the protective structure (2) is slidably connected to a lifting structure (5), the inner cavity of the lifting structure (5) is rotatably connected to a placement structure (6), the inner cavity of the placement structure (6) is provided with an adjustment structure (7), the upper end surface of the placement structure (6) is symmetrically provided with a clamping structure (8) along the center line, and the lower front end of the lifting structure (5) is symmetrically provided with an angle adjustment structure (9) along the center line.

2. A library reading device that can be adjusted according to demand according to claim 1, characterized in that: The protection structure (2) comprises a protection frame (21) fixedly connected to the upper end surface of the bottom plate (1); the inner cavity of the protection frame (21) is symmetrically fixedly connected to the limit rod (22) along the center line; the inner cavity of the protection frame (21) is rotatably connected to a threaded rod (23) between the two protection rods (22); and the upper end surface of the protection frame (21) is fixedly connected to the top plate (3).

3. A library reading device that can be adjusted according to demand according to claim 2, characterized in that: The driving structure (4) comprises a driving frame (41) fixedly connected to the middle part of the upper end surface of the top plate (3); the inner cavity of the driving frame (41) is rotatably connected to a driving rod (42); the upper end surface of the top plate (3) is located behind the driving rod (42) and is symmetrically rotatably connected to a worm gear (43); the upper end surface of the top plate (3) is located in the middle part of the inner cavity of the driving frame (41); and the output end of the driving motor (44) is fixedly connected to the driving rod (42); The outer surface of the driving rod (42) is symmetrically provided with two sections of threads in opposite directions. The threads on the outer surface of the driving rod (42) are meshed with the worm gear (43). The rotating shaft on the upper end surface of the threaded rod (23) penetrates the top plate (3) and is fixedly connected to the worm gear (43).

4. A library reading device that can be adjusted according to demand according to claim 2, characterized in that: The lifting frame (5) comprises a lifting plate (51) slidably connected to the inner cavity of the protection frame (21); a threaded rod (23) passes through the lifting plate (51) and is threadedly connected; a placement groove (52) is provided in the middle of the upper end surface of the lifting plate (51); the placement groove (52) is rotatably connected to a placement structure (6) via a rotating shaft in the middle of the inner cavity; and a limiting block (53) is fixedly connected to the inner cavity of the placement groove (52) symmetrically along the center point.

5. A library reading device that can be adjusted according to demand according to claim 4, characterized in that: The placement structure (6) comprises a placement plate (61) rotatably connected to the inner cavity of the placement groove (52); an adjustment groove (62) is provided in the middle of the upper end surface of the placement plate (61); a protective plate (63) is symmetrically fixedly connected to the upper end surface of the inner cavity of the adjustment groove (62) along the center line; an adjustment rod (64) is symmetrically rotatably connected to the inner cavity of the adjustment groove (62) along the center line; two sections of threads in opposite directions are symmetrically provided on the outer surface of the adjustment rod (64); a clamping structure (8) is symmetrically provided in the inner cavity of the adjustment groove (62); and an adjustment structure (7) is provided on the lower end surface of the inner cavity of the adjustment groove (62).

6. A library reading device that can be adjusted according to demand according to claim 5, characterized in that: The adjustment structure (7) comprises an adjustment motor (71) fixedly connected to the middle of the left side of the inner cavity of the adjustment groove (62); the output end of the adjustment motor (71) is fixedly connected to a driving wheel (72); the middle of the outer surfaces of the two adjustment rods (63) are fixedly connected to pulleys (74); the outer surfaces of the two pulleys (74) are transmission-connected to belts (73); the inner cavity of the belt (73) is transmission-connected to the outer surface of the driving wheel (72); the radius of the outer surface of the driving wheel (72) is greater than the radius of the outer surface of the pulley (74).

7. The library reading device that can be adjusted according to demand according to claim 5, characterized in that: The clamping structure (8) comprises a lower placement plate (81) symmetrically slidably connected to both sides of the inner cavity of the adjustment groove (62); an electric telescopic rod (82) is symmetrically fixedly connected to the side of the upper end surface of the lower placement plate (81) away from the center point of the protective frame (21); an upper placement plate (83) is fixedly connected to the upper end of the electric telescopic rod (82); and anti-slip belts (84) are fixedly connected to the upper and lower sides between the upper placement plate (83) and the lower placement plate (81), respectively.

8. The library reading device that can be adjusted according to demand according to claim 5, characterized in that: The angle adjustment structure (9) comprises an adjustment frame (91) symmetrically fixedly connected to the front of the lower end of the lifting plate (51) along the center line. The adjustment frame (91) is specifically a quarter-circular ring structure. A mounting frame (93) is fixedly connected between the adjustment frame (91) and the lifting plate (51) on one side close to the center of the circle. Limiting grooves (92) are provided on both the left and right sides of the adjustment frame (91). Limiting structures (94) matching the limiting grooves (92) are provided on the front of the left and right end faces of the placement plate (62).

9. The library reading device that can be adjusted according to demand according to claim 8, characterized in that: The limiting structure (94) comprises mounting grooves (941) provided on the front end surfaces of the left and right sides of the placement plate (62); a spring (942) is fixedly connected to one end of the inner cavity of the mounting groove (941) away from the protective frame (21); a limiting block (943) is fixedly connected to the side of the spring (942) away from the mounting groove (941); the limiting block (943) is slidably connected to the inner cavity of the mounting groove (941); and the outer surface of the limiting block (943) matches the limiting groove (92).

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