A backrest

Abstract

The embodiment of the present application provides a back frame, comprising: a main rod, the main rod has a first face and a second face which are opposite to each other; a plurality of first connecting pieces, the plurality of first connecting pieces are arranged at intervals on the first face, the first connecting piece is provided with a first connecting part for connection in a first direction and a second connecting part for connection in a second direction, the first direction and the second direction are cross directions; a plurality of second connecting pieces, the plurality of second connecting pieces are arranged at intervals on the main rod, and the second connecting piece is provided with a third connecting part, and the third connecting part is located on the side of the second face. According to the technical scheme provided by the embodiment of the present application, the back frame can be applied to the installation of a plurality of display screens in cooperation with the frame, the back frame can be installed at the joint of two display screens, and the first connecting part and the second connecting part are connected with the frame, so that the wind resistance of the display screen can be strengthened, and the third connecting part is connected with the external structure, so that the position stability of the frame and the display screen can be strengthened.

Description

Technical Field

[0001] This application relates to the field of display screen accessories technology, and in particular to a back bracket. Background Technology

[0002] Currently, the large display screens used are composed of multiple displays connected in sequence. When connecting them, if the displays are only installed on the frame, the wind resistance of the displays will be weak, and the displays will easily detach from the frame, resulting in display loss on the large screen and damage to the displays. In more serious cases, the detached displays may hit people or objects, causing adverse effects.

[0003] Therefore, how to enhance the wind resistance of displays has become a challenge in the industry. Utility Model Content

[0004] In view of the above problems, this application presents an embodiment, the purpose of which is to provide a back frame that can enhance the wind resistance of the display screen.

[0005] To achieve this objective, the embodiments of this application provide the following technical solutions:

[0006] This application provides a back frame, including:

[0007] A main rod, the main rod having a first side and a second side facing opposite directions;

[0008] A plurality of first connectors are spaced apart on the first surface. Each first connector has a first connecting portion for connecting along a first direction and a second connecting portion for connecting along a second direction. The first direction and the second direction are intersecting directions.

[0009] Multiple second connectors are spaced apart on the main body rod, and each second connector has a third connecting portion located on the side where the second surface is located.

[0010] Optionally, the first connector is a first U-shaped structure, the bottom of the first connector is connected to the first surface, and the sidewall of the first connector extends away from the first surface;

[0011] The first connecting portion includes: a side wall of the first connector and a first connecting hole disposed on the side wall of the first connector, wherein the first connecting hole extends through along the first direction;

[0012] The second connecting portion includes: a first connecting lug disposed on the side wall of the first connector and extending away from the other side wall, and a second connecting hole disposed on the first connecting lug, the second connecting hole being through in the second direction.

[0013] Optionally, along the length of the main body rod, the sidewall of the first connector includes a first sidewall and a second sidewall, and the height of the first sidewall is higher than the height of the second sidewall relative to the bottom of the first connector.

[0014] The first connecting hole is disposed on the first sidewall;

[0015] The first connecting ear is disposed on the second side wall.

[0016] Optionally, the second connector includes a support member and a stacked connecting block;

[0017] The support member has a second U-shaped structure. The side wall of the support member is provided with a second connecting ear extending away from the other side wall. The second connecting ear is provided with a third connecting hole, which is through along the second direction. The support member covers the main body rod, and the second connecting ear is located on the side where the second surface is located.

[0018] The stacked connecting block is the third connecting part, which spans the main body rod and is connected to the two second connecting ears respectively.

[0019] Optionally, the stacked connecting block is provided with quick-connect assembly holes.

[0020] Optionally, the main body rod has a first end and a second end along its length.

[0021] The first end is provided with a cascading component, which can be connected to the second end of the other main body rod so that the two main body rods are connected end to end along the length direction of the main body rods.

[0022] Optionally, the cascade is a third U-shaped structure, the inner diameter of the cascade is larger than the outer diameter of the main rod, and the second end of the other main rod can extend into the cascade and connect to the cascade.

[0023] Optionally, the open end of the cascade is located on the side where the first surface is located;

[0024] The cascaded component has at least two third connecting holes on its side wall, and the second end of the main body rod has at least two fourth connecting holes. When the second end of the other main body rod extends into the cascaded component, the third connecting holes and the fourth connecting holes are positioned to correspond to each other, and the connection between the two main body rods is achieved by fasteners.

[0025] Optionally, it also includes a lifting ring, which is detachably connected to the cascade, and at least a portion of the lifting ring is housed within the cascade.

[0026] Alternatively, the main body rod may also be provided with multiple limiting holes.

[0027] According to the technical solution provided in the embodiments of this application, the back frame can be used in conjunction with the frame for the installation of multiple displays. The back frame can be installed at the splicing point of two displays and connected to the frame through the first connecting part and the second connecting part. Thus, the back frame can enhance the wind resistance of the displays in the first and second directions. At the same time, it can enhance the positional stability of the frame and the displays through the third connecting part connected to the external structural components. In addition, the back frame also has the characteristics of simple structure, stability, simple operation, and strong practicality. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the back frame structure provided in an embodiment of this application;

[0030] Figure 2 for Figure 1 A schematic diagram of the back frame from another angle;

[0031] Figure 3 for Figure 1 Enlarged structural diagram at point A;

[0032] Figure 4 for Figure 2 Enlarged structural diagram at point B;

[0033] Figure 5 for Figure 1 Enlarged structural diagram at point C;

[0034] Figure 6 for Figure 2 Enlarged structural diagram at point D;

[0035] Figure 7 This is a schematic diagram of the structure in which two back frames are connected by a cascade component, as provided in an embodiment of this application.

[0036] Figure 8 for Figure 7 A schematic diagram of the back frame from another angle;

[0037] Figure 9 for Figure 7 Enlarged structural diagram at point E;

[0038] Figure 10 This is a schematic diagram of the structure of a back frame trolley for transporting back frames provided in an embodiment of this application;

[0039] Figure 11 This is a partially enlarged schematic diagram of the structure of the back frame trolley provided in the embodiments of this application, showing the state without the back frame placed;

[0040] Figure 12 This is a partially enlarged schematic diagram of the structure of the back frame trolley provided in the embodiments of this application, showing the state in which the back frame is placed.

[0041] Explanation of reference numerals in the attached figures:

[0042] 10: Main body rod; 11: First surface; 12: Second surface; 101: First end; 102: Second end; 13: Cascade; 131: Third connecting hole; 132: Second quick release pin; 1021: Fourth connecting hole; 103: Limiting hole;

[0043] 20: First connector; 21: First connecting part; 22: Second connecting part; 211: First connecting hole; 221: First connecting lug; 222: Second connecting hole; 212: First sidewall; 213: Second sidewall; 23: First quick-release pin;

[0044] 30: Second connector; 31: Third connector; 301: Support; 3011: Second connector ear; 3012: Third connector hole; 302: Stacking connector block; 3021: Quick-connect assembly hole;

[0045] 40: Rings;

[0046] 50: Backrest trolley; 51: Load-bearing platform; 52: Limiting block; 521: Limiting groove; 522: Groove wall; 523: Through hole; 524: Limiting pin. Detailed Implementation

[0047] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present application, not the entire structure.

[0048] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0050] Figure 1 This is a schematic diagram of the back frame structure provided in an embodiment of this application. Figure 2 for Figure 1 The diagram shows the structure of the back frame from another angle, as shown below. Figure 1 and Figure 2 As shown.

[0051] This application provides a back frame, including: a main rod 10, a plurality of first connectors 20, and a plurality of second connectors 30. The main rod 10 has a first surface 11 and a second surface 12 facing opposite directions; the plurality of first connectors 20 are spaced apart on the first surface 11, each first connector 20 having a first connecting portion 21 for connection along a first direction and a second connecting portion 22 for connection along a second direction, the first and second directions being intersecting; the plurality of second connectors 30 are spaced apart on the main rod 10, each second connector 30 having a third connecting portion 31 located on the side where the second surface 12 is located.

[0052] One application of the back frame is for the installation of display screens. For example, it can be used to install LED display screens, which include a frame and display modules comprising multiple displays mounted on the frame. The frame includes multiple crossbeams and multiple longitudinal beams, and the back frame is connected to these beams. The back frame is installed at the junction of two displays in the left-right direction or at the junction of two displays in the up-down direction. One of the first and second directions is the left-right direction, and the other is the up-down direction. The back frame is connected to the frame via a first connecting part 21 and a second connecting part 22, thereby enhancing the wind resistance of the displays in the first and second directions. Simultaneously, it connects to external structural components (such as a steel frame at the installation site) via a third connecting part 31, enhancing the positional stability of the frame and displays. The back frame can also be used for climbing. Furthermore, the back frame is characterized by its simple structure, stability, ease of operation, and high practicality.

[0053] The technical solutions provided in the embodiments of this application will be described in further detail below.

[0054] In this embodiment, the main body rod 10 of the back frame is, but is not limited to, a square tube. The square tube can fit better with the display screen, thereby making the back frame and the display screen more closely contact each other, thus more effectively enhancing the wind resistance of the display screen.

[0055] Combination Figure 1 and Figure 2 See Figures 3 to 6 In one embodiment of this application, the first connector 20 is implemented as a first U-shaped structure, with its bottom connected to the first surface 11 and its sidewalls extending away from the first surface 11. The first connector 20 may be connected to the main body rod 10 by fasteners such as bolts or screws, or it may be connected by welding.

[0056] The first connector 20 has a first connecting portion 21 and a second connecting portion 22. The first connecting portion 21 includes a side wall of the first connector 20 and a first connecting hole 211 disposed on the side wall of the first connector 20, the first connecting hole 211 being through in a first direction. The second connecting portion 22 includes a first connecting lug 221 disposed on the side wall of the first connector 20 and extending away from the other side wall, and a second connecting hole 222 disposed on the first connecting lug 221, the second connecting hole 222 being through in a second direction.

[0057] In use, the first connecting part 21 can cover the crossbeam or longitudinal beam of the frame within the first U-shaped structure through the two side walls of the first connecting member 20, and then the first quick-release pin 23 is inserted into the first connecting hole 211 to realize the connection between the first connecting part 21 and the frame. The first connecting ear 221 is connected to the crossbeam or longitudinal beam on both sides of the main body rod 10 by fasteners such as bolts to realize the connection between the second connecting part 22 and the frame.

[0058] It should be noted here that, Figure 3 and Figure 4 The first connector 20 shown is the same, only the angle shown is different. Similarly, Figure 5 and Figure 6 The first connector 20 shown is also the same, only the angle shown is different. Meanwhile, Figure 3 and Figure 4 The figures shown are as follows: Figure 5 and Figure 6 The examples shown are all first connectors 20. Due to differences in the number of first connecting parts 21 and second connecting parts 22, their structures differ, for example... Figure 3 and Figure 4 The first connector 20 shown includes two first connecting parts 21, and a second connecting part 22 is provided between the two first connecting parts 21. Figure 5 and Figure 6 The first connector 20 shown includes a first connecting portion 21 and a second connecting portion 22. Of course, in this embodiment, the number of the first connecting portion 21 and the second connecting portion 22 can be set according to different needs, and this embodiment does not specifically limit this.

[0059] See also Figures 3 to 6 In this embodiment, along the length of the main rod 10, the sidewall of the first connector 20 includes a first sidewall 212 and a second sidewall 213. The height of the first sidewall 212 is higher than the height of the second sidewall 213 relative to the bottom of the first connector 20. A first connecting hole 211 is disposed on the first sidewall 212, and a first connecting ear 221 is disposed on the second sidewall 213. With this arrangement, the first connecting ear 221 can avoid the crossbeams or longitudinal beams on the frame, effectively reducing interference between the first connecting ear 221 and the frame. For example, at the position where the crossbeams and longitudinal beams of the frame are connected in a cross shape, the first sidewall 212 can wrap around the longitudinal beam, and the height of the second sidewall 213 is lower than the height of the first sidewall 212, allowing the longitudinal beam to penetrate deeper into the first U-shaped structure. When the longitudinal beam is aligned with the first connecting part 21, the second connecting ear 3011 can abut against the crossbeam of the frame, thereby achieving the connection between the second connecting ear 3011 and the crossbeam through bolts.

[0060] Combination Figure 1 and Figure 2 See Figure 3 , Figure 5 and Figure 6 In one embodiment of this application, the second connector 30 may be implemented as follows: the second connector 30 includes a support 301 and a stacked connecting block 302; the support 301 has a second U-shaped structure, and a second connecting ear 3011 extending away from the other sidewall is provided on the sidewall of the support 301; the second connecting ear 3011 has a third connecting hole 3012131, which is through along the second direction; the support 301 covers the main body rod 10, and the second connecting ear 3011 is located on the side where the second surface 12 is located; the support 301 is connected to the main body rod 10 by means of fasteners, such as bolts and screws, or by welding. The stacked connecting block 302 is connected to the support 301 by means of fasteners, among other things.

[0061] The stacked connecting block 302 is the third connecting part 31. The stacked connecting block 302 spans the main body rod 10 and is connected to two second connecting ears 3011 respectively. The support member 301 stably connects the stacked connecting block 302 to the main body rod 10. The stacked connecting block 302 can be connected to external structural components (such as steel structure frames at the installation site), thereby enhancing the overall positional stability of the back frame. When the back frame is connected to the frame, it can also effectively enhance the positional stability of the frame and the display screen.

[0062] Furthermore, to enable rapid assembly and disassembly of the back frame, the stacking connection block 302 is provided with quick-connect assembly holes 3021. The external structural component is provided with a quick-connect assembly head that mates with the quick-connect assembly hole 3021. The quick-connect assembly hole 3021 and the quick-connect assembly head can be quickly assembled and disassembled, thereby enabling the back frame to be quickly assembled and disassembled with the external structural component, thus effectively improving the assembly and disassembly efficiency.

[0063] In this embodiment, the main frame 10 can be set to different lengths according to different needs. For example, the main frame 10 can be set to 1 meter, 2 meters, and N meters. At the same time, according to different needs, two back frames can also be connected end to end to form a longer back frame. For example, two 1-meter back frames can be connected end to end to form a 2-meter back frame, or a 1-meter back frame and a 2-meter back frame can be combined to form a 2-meter back frame, thereby making the use of the back frame more flexible.

[0064] For better implementation of combined use, see [link / reference]. Figure 1 and Figure 2In some feasible embodiments of this application, the main body rod 10 has a first end 101 and a second end 102 along its length; a cascading member 13 is provided on the first end 101, which can be connected to the second end 102 of another main body rod 10, so that the two main body rods 10 are connected end to end along the length of the main body rod 10. For example, see Figure 7 and Figure 8 The main rods 10 on the two back frames are main rod 10a and main rod 10b, respectively. The cascading member 13 on the first end 101a of the main rod 10a is connected to the second end 102b of the main rod 10b, so that the main rods 10a and 10b can achieve the cascading function.

[0065] Combination Figure 7 and Figure 8 See Figure 9 In one embodiment of this application, the cascade member 13 can be implemented as a third U-shaped structure, with its inner diameter larger than the outer diameter of the main body rod 10. The second end 102 of the other main body rod 10 can extend into and connect to the cascade member 13. The cascade member 13 can cover the second end 102 of the other main body rod 10, increasing the contact area between the cascade member 13 and the second end 102, thus enhancing connection stability.

[0066] Further, see also Figure 8 and Figure 9 The open end of the cascade 13 is located on the side where the first surface 11 is located. At least two third connecting holes 3012131 are provided on the side wall of the cascade 13, and at least two fourth connecting holes 1021 are provided on the second end 102 of the main body rod 10. When the second end 102 of another main body rod 10 extends into the cascade 13, the third connecting holes 3012131 and the fourth connecting holes 1021 correspond in position, and the connection between the two main body rods 10 is achieved by fasteners. For example, the cascade 13a on the main body rod 10a is connected to the second end 102b on the main body rod 10b. After the second end 102b extends into the cascade 13a, the two third connecting holes 3012131a on the cascade 13 and the two fourth connecting holes 1021 on the second end 102b (see fourth connecting hole 1021 for details) are connected. Figure 7 As shown in the diagram, the cascaded component 13a is inserted into the third connecting hole 3012131a and the fourth connecting hole 1021 through the third connecting hole 3012131, thus connecting the cascaded component 13a to the second end 102b. When the third connecting hole 3012131 is removed, the cascaded component 13a can be separated from the second end 102b. The use of at least two third connecting holes 3012131 effectively prevents mutual rotation between the cascaded component 13a and the second end 102 of the other main body rod 10, enhancing stability.

[0067] In some feasible embodiments of this application, when it is not necessary to combine the two back frames, the cascade 13 can also be used to assist in the hoisting of the back frames. For example, after the third connecting hole 3012131 is inserted into the third connecting hole 3012131, the third connecting hole 3012131 can be connected by a rope or hook to achieve hoisting.

[0068] Furthermore, to make hoisting operations more convenient, see... Figure 2 The back frame also includes lifting rings 40, which are detachably connected to the cascade 13, with at least a portion of the lifting rings 40 housed within the cascade 13. The lifting rings 40 and the cascade 13 can also be connected via third connecting holes 3012131. After the lifting rings 40 are installed, they can be connected to ropes or hooks to complete the lifting operation.

[0069] See also Figure 1 In some feasible embodiments of this application, the main body rod 10 is also provided with a plurality of limiting holes 103. The limiting holes 103 and the second connecting member 30 can be used to limit the movement of the back frame, thereby completing the smooth transportation of the back frame.

[0070] For example, the back frame can be used Figure 10 The back frame trolley 50 shown is used for transportation. The back frame trolley 50 has multiple carrying platforms 51 stacked along the height direction. Each carrying platform 51 has multiple limiting component groups along the width direction of the back frame trolley 50. Each limiting component group has multiple limiting blocks 52 along the length direction of the back frame trolley 50.

[0071] See Figure 11 Each limiting block 52 has two limiting grooves 521, such as limiting groove 521a and limiting groove 521b, and the positions of the limiting grooves 521a and limiting grooves 521b of multiple limiting blocks 52 correspond to each other. The limiting grooves 521a and 521b share a common groove wall 522, namely groove wall 522b. Through holes 523 are provided on groove walls 522a and 522b respectively, and limiting pins 524 are provided on the through holes 523.

[0072] Combination Figure 11 See Figure 12 When the back frame is placed on the limiting component group, the back frame spans multiple limiting blocks 52 within a limiting component group and is respectively embedded in the limiting groove 521 of the corresponding position of each limiting block 52, such as the back frame being embedded in the limiting groove 521a of the limiting block 52.

[0073] Meanwhile, the positions of the multiple second connectors 30 on the back frame correspond one-to-one with the positions of the multiple limiting blocks 52, and the correspondence is staggered. For example, taking four second connectors 30 and four limiting blocks 52 as an example... Figure 12Taking the orientation as an example, the first second connector 30 is located to the left of its corresponding limiting block 52, the next second connector 30, that is, the second second connector 30, is located to the right of its corresponding limiting block 52, the third second connector 30 is located to the left of its corresponding limiting block 52, and the fourth second connector 30 is located to the right of its corresponding limiting block 52.

[0074] At the same time, the multiple limiting holes 103 on the back frame limit the through holes 523 on the block 52 respectively. At this time, the limiting pin 524 can extend into the limiting groove 521 and into the limiting hole 103.

[0075] After the back frame is placed on the limiting assembly, the groove wall 522 of the limiting groove 521 can effectively limit the displacement of the back frame along the width direction of the back frame trolley 50. The cooperation between the limiting block 52 and the second connecting member 30 can effectively limit the displacement of the back frame along the length direction of the back frame trolley 50. The cooperation between the limiting pin 524 and the limiting hole 103 can not only effectively limit the displacement of the back frame along the length and width directions of the back frame trolley 50, but also effectively limit the displacement of the back frame along the height direction of the back frame trolley 50. This avoids displacement of the back frame relative to the back frame trolley 50 in any direction, so that the back frame is stably placed on the back frame trolley 50, thereby achieving the purpose of transporting the back frame smoothly by the back frame trolley 50.

[0076] In summary, according to the technical solution provided in the embodiments of this application, the back frame can be used in conjunction with the frame for the installation of multiple displays. The back frame can be installed at the splicing point of two displays and connected to the frame through the first connecting part 21 and the second connecting part 22. Thus, the back frame can enhance the wind resistance of the displays in the first and second directions. At the same time, it can be connected to the external structural components through the third connecting part 31, which can enhance the positional stability of the frame and the displays. In addition, the back frame can also be used for climbing.

[0077] In addition, the backpack frame is characterized by its simple and stable structure, easy operation, and strong practicality.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A back frame, characterized in that, include: A main rod, the main rod having a first side and a second side facing opposite directions; A plurality of first connectors are spaced apart on the first surface. Each first connector has a first connecting portion for connecting along a first direction and a second connecting portion for connecting along a second direction. The first direction and the second direction are intersecting directions. Multiple second connectors are spaced apart on the main body rod, and each second connector has a third connecting portion located on the side where the second surface is located.

2. The back frame according to claim 1, characterized in that, The first connector is a first U-shaped structure, the bottom of the first connector is connected to the first surface, and the sidewall of the first connector extends away from the first surface; The first connecting portion includes: a side wall of the first connector and a first connecting hole disposed on the side wall of the first connector, wherein the first connecting hole extends through along the first direction; The second connecting portion includes: a first connecting lug disposed on the side wall of the first connector and extending away from the other side wall, and a second connecting hole disposed on the first connecting lug, the second connecting hole being through in the second direction.

3. The back frame according to claim 2, characterized in that, Along the length of the main rod, the sidewall of the first connector includes a first sidewall and a second sidewall, and the height of the first sidewall is higher than the height of the second sidewall relative to the bottom of the first connector. The first connecting hole is disposed on the first sidewall; The first connecting ear is disposed on the second side wall.

4. The back frame according to claim 1, characterized in that, The second connector includes a support member and a stacked connecting block; The support member has a second U-shaped structure. The side wall of the support member is provided with a second connecting ear extending away from the other side wall. The second connecting ear is provided with a third connecting hole, which is through along the second direction. The support member covers the main body rod, and the second connecting ear is located on the side where the second surface is located. The stacked connecting block is the third connecting part, which spans the main body rod and is connected to the two second connecting ears respectively.

5. The back frame according to claim 4, characterized in that, The stacked connecting block is provided with quick-connect assembly holes.

6. The back frame according to any one of claims 1 to 5, characterized in that, The main rod has a first end and a second end along its length; The first end is provided with a cascading component, which can be connected to the second end of the other main body rod so that the two main body rods are connected end to end along the length direction of the main body rods.

7. The back frame according to claim 6, characterized in that, The cascade is a third U-shaped structure, the inner diameter of the cascade is larger than the outer diameter of the main rod, and the second end of the other main rod can extend into the cascade and connect to the cascade.

8. The back frame according to claim 7, characterized in that, The open end of the cascade is located on the side where the first surface is located; The cascaded component has at least two third connecting holes on its side wall, and the second end of the main body rod has at least two fourth connecting holes. When the second end of the other main body rod extends into the cascaded component, the third connecting holes and the fourth connecting holes are positioned to correspond to each other, and the connection between the two main body rods is achieved by fasteners.

9. The back frame according to claim 7, characterized in that, It also includes lifting rings, which are detachably connected to the cascade, with at least a portion of the lifting rings housed within the cascade.

10. The back frame according to any one of claims 1 to 5, characterized in that, The main rod is also provided with multiple limiting holes.

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