A municipal engineering assembled fence

Abstract

The utility model discloses a municipal engineering assembled fence, which belongs to the technical field of municipal engineering facilities, and comprises a first column and a second column vertically standing on a horizontal plane, two groups of crossbar assemblies are arranged between the first column and the second column, and the two groups of crossbar assemblies are arranged up and down, and the crossbar assembly comprises a main crossbar and a secondary crossbar, and the main crossbar is axially provided with a secondary crossbar groove, and the secondary crossbar is inserted into the secondary crossbar groove, and the end surfaces of the main crossbar and the secondary crossbar that are away from each other are fixedly connected with a connecting block, and the other end surface of the connecting block is fixedly connected with a mounting block, and the side walls of the first column and the second column are both provided with an L-shaped mounting groove, and the vertical groove part of the L-shaped mounting groove is located below the horizontal groove part, and the cross section of the mounting groove is a convex shape, and the mounting block is located in the wider part of the mounting groove, and the connecting block is located in the narrower part of the mounting groove, and a plurality of groups of vertical rod assemblies are arranged between the two crossbar assemblies. Through the above arrangement, the assembly of the fence is simplified and the assembly efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of municipal engineering facilities, and in particular relates to a municipal engineering assembled fence. Background Art

[0002] Municipal engineering refers to the construction of municipal facilities. In my country, municipal facilities refer to various buildings, structures, equipment, etc. that are set up within the planning and construction scope of urban areas, towns, and villages to provide paid or free public products and services to residents based on government responsibilities and obligations. In the process of municipal engineering construction, it is often necessary to use fences to enclose some roads or places to prevent pedestrians from accidentally entering.

[0003] As proposed in the patent document with announcement number CN217300122U, a municipal engineering assembled fence rotates the rotating frame on the surface of the first column and the second column to make them horizontal, then pulls out the long rod in the rotating frame on the surface of the first column and inserts it into the square frame on the surface of the second column, and then inserts the insertion rod into the slot on the surface of the long rod to limit the movement of the long rod, and at the same time tightens the screw on the surface of the rotating frame so that the screw limits the long rod, and then slides the round rod toward the inside of the cylinder, and then aligns the round rod and the fixed rod with the circular groove on the rotating frame or the long rod respectively, and then loosens the round rod. At this time, the round rod will be pushed by the spring between it and the inner wall of the cylinder and inserted into the circular groove. At this time, the round rod and the fixed rod are both inserted into the circular grooves on the upper and lower rotating frames or the surfaces of the long rods, and the fence assembly is completed.

[0004] Another example is an assembled plastic fence proposed in the patent document with announcement number CN212224879U. The utility model cooperates with an installation plate, an installation hole, a vertical tube, a horizontal plate, a column, a fixing plate, a first threaded hole, a first slot, a first bolt, a sleeve, a connecting plate, a second threaded hole, a second slot, a second bolt, a round hole, a threaded groove, a vertical rod, a screw thread, an L-shaped rod, a connecting rod and a round tube. It has the advantages of easy assembly and splicing, and solves the problem that most of the existing plastic fences are integrated, large in size, more troublesome to carry, and occupy a large space.

[0005] After reading the above documents, it was found that the prefabricated fence proposed in the document requires the use of multiple bolts when installing the cross bar between the two columns, and then fixes the cross bar through the cooperation between the bolts and nuts. In the process, a large number of small parts such as bolts and nuts are used, which makes the steps more cumbersome and needs to be optimized. Utility Model Content

[0006] The purpose of the utility model is to provide a municipal engineering assembled fence to solve the problems raised in the above background technology.

[0007] In order to achieve the above purpose, this application adopts the following technical solutions:

[0008] A prefabricated fence for municipal engineering comprises a first column and a second column vertically erected on a horizontal plane, two groups of cross bar assemblies are arranged between the first column and the second column, and the two groups of cross bar assemblies are arranged up and down, the cross bar assembly comprises a main cross bar and a secondary cross bar, the main cross bar is axially provided with a secondary cross bar groove, the secondary cross bar is inserted into the secondary cross bar groove, the main cross bar and the secondary cross bar are fixedly connected with connecting blocks on the end faces of one end away from each other, and the other end face of the connecting block is fixedly connected with a mounting block, the first column and the second column are provided with an L-shaped mounting groove on the side wall, the vertical groove portion of the L-shaped mounting groove is located below the horizontal groove portion, the cross section of the mounting groove is a convex shape, the mounting block is located at the wider part of the mounting groove, and the connecting block is located at the narrower part of the mounting groove, and multiple groups of vertical bar assemblies are also arranged between the two cross bar assemblies.

[0009] Preferably, a plurality of positioning grooves are provided on the peripheral side wall of the main cross bar, and the plurality of positioning grooves are evenly distributed along the length direction of the main cross bar. The secondary cross bar groove axially penetrates the plurality of positioning grooves, and a positioning block is fixedly connected to one end of the secondary cross bar close to the main cross bar, and the positioning block is arranged in one of the positioning grooves.

[0010] Preferably, the positioning groove is divided into a transition groove and a center groove, the center groove is coaxially arranged with the secondary cross bar groove, and the cross-sectional area of ​​the center groove is larger than the cross-sectional area of ​​the secondary cross bar groove, one end of the transition groove is connected with the center groove, and the other end of the transition groove passes through the side wall of the main cross bar, the width of the transition groove is the same as the width of the positioning block, and spring block grooves are provided on both side walls of the positioning block, a spring block is movably arranged in the spring block groove, and a spring is fixedly connected between the spring block and the spring block groove.

[0011] Preferably, the vertical rod assembly includes a main vertical rod and a secondary vertical rod, the main vertical rod is axially provided with a telescopic groove, the secondary vertical rod is movably arranged in the telescopic groove, the other end of the secondary vertical rod passes through the telescopic groove, the end of the secondary vertical rod located in the telescopic groove is also fixedly connected to a limiting block, and threaded columns are fixedly connected to the ends of the main vertical rod and the secondary vertical rod that are away from each other, and a plurality of threaded holes are equidistantly provided on the peripheral side walls of the main cross rod and the secondary cross rod along the length direction, and the threaded columns are threadedly matched with the threaded holes.

[0012] Preferably, a first chamfer is provided on the side wall at the notch of the installation groove.

[0013] Preferably, the transverse groove portion of the mounting groove is arranged to be inclined upward, and an inclined angle between the transverse groove portion of the mounting groove and the horizontal direction is 15° to 30°.

[0014] Preferably, a second chamfer is provided on the top side wall of the transition groove.

[0015] Preferably, anti-slip grooves are vertically provided on the peripheral side walls of the main vertical rod and the auxiliary vertical rod.

[0016] Preferably, a winding groove is provided on the side wall of the first column in the extension direction, a rotating rod is axially rotatably connected in the winding groove, a winding spring is provided on the top of the winding groove, the inner end of the winding spring is fixedly connected to the top side wall of the rotating rod, the outer end of the winding spring is fixedly connected to the top inner wall of the winding groove, a wire mesh is wound on the rotating rod, a hook is also fixedly connected to the free end of the wire mesh, and a hook groove adapted to the hook is opened on the side wall of the second column.

[0017] To sum up, the technical effects and advantages of the utility model are as follows: the utility model is provided with a cross bar assembly consisting of a main cross bar and a secondary cross bar, and a mounting block is connected to the ends of the main cross bar and the secondary cross bar that are far away from each other. Furthermore, a mounting groove compatible with the mounting block is opened on the side walls of the first column and the second column, and then the mounting block is pushed into the mounting groove to complete the assembly of the main cross bar, the secondary cross bar, the first column and the second column, thereby replacing the use of bolts and nuts in the prior art, thereby simplifying the assembly steps and improving the assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the utility model;

[0019] Figure 2 It is a schematic diagram of the installation slot notch;

[0020] Figure 3 This is a schematic diagram of the front view of the installation slot;

[0021] Figure 4 It is a schematic diagram of the location of the connection block and the installation block;

[0022] Figure 5 It is a schematic diagram of the connection position of the threaded column;

[0023] Figure 6 A schematic cross-sectional view of the main vertical pole;

[0024] Figure 7 Schematic diagram of the internal structure of the center tank;

[0025] Figure 8 This is a schematic diagram of the internal structure of the positioning block;

[0026] Fig. 9 It is a schematic diagram of the internal structure of the winding tank;

[0027] Fig.10 for Figure 1 Enlarged schematic diagram at point A in the middle.

[0028] In the figure: 1. first column; 2. second column; 3. main cross bar; 4. secondary cross bar; 5. secondary cross bar groove; 6. connecting block; 7. mounting block; 8. mounting groove; 9. positioning block; 10. transition groove; 11. center groove; 12. spring block groove; 13. spring block; 14. spring; 15. main vertical bar; 16. secondary vertical bar; 17. telescopic groove; 18. limit block; 19. threaded column; 20. threaded hole; 21. first chamfer; 22. second chamfer; 23. anti-slip pattern; 24. winding groove; 25. rotating rod; 26. winding spring; 27. wire mesh; 28. hook; 29. ​​hook groove. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0031] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0032] like Figure 1-4 A municipal engineering assembled fence is shown, comprising a first column 1 and a second column 2 vertically erected on a horizontal plane, two groups of cross bar assemblies are arranged between the first column 1 and the second column 2, and the two groups of cross bar assemblies are arranged up and down, the cross bar assembly comprises a main cross bar 3 and a secondary cross bar 4, a secondary cross bar groove 5 is axially opened on the main cross bar 3, and the secondary cross bar 4 is inserted into the secondary cross bar groove 5, a connecting block 6 is fixedly connected to the end surface of one end of the main cross bar 3 and the secondary cross bar 4 away from each other, and a mounting block 7 is fixedly connected to the other end surface of the connecting block 6, an L-shaped mounting groove 8 is opened on the side wall of the first column 1 and the second column 2, the vertical groove portion of the L-shaped mounting groove 8 is located below the horizontal groove portion, the cross section of the mounting groove 8 is a convex shape, the mounting block 7 is located in the wider part of the mounting groove 8, and the connecting block 6 is located in the narrower part of the mounting groove 8.

[0033] It should be noted that: when assembling the fence, the total length of the main cross bar 3 and the secondary cross bar 4 is adjusted by moving the position of the secondary cross bar 4 in the secondary cross bar groove 5 according to needs, and the first column 1 and the second column 2 are placed on a horizontal plane, and the side walls of the first column 1 and the second column 2 with the mounting groove 8 are placed opposite to each other, and then the mounting block 7 on the adjusted main cross bar 3 is aligned with the wider part of the mounting groove 8 on the first column 1, and the mounting block 7 on the secondary cross bar 4 is aligned with the wider part of the mounting groove 8 on the second column 2, and the mounting block 7 is pushed into the mounting groove 8. After the mounting block 7 enters the vertical groove part from the horizontal groove part of the mounting groove 8, the assembly of the main cross bar 3 and the secondary cross bar 4 is completed.

[0034] The above arrangement is provided with a crossbar assembly consisting of a main crossbar 3 and a secondary crossbar 4, and a mounting block 7 is connected to the ends of the main crossbar 3 and the secondary crossbar 4 that are far away from each other. Furthermore, a mounting groove 8 adapted to the mounting block 7 is opened on the side walls of the first column 1 and the second column 2, and then the mounting block 7 is pushed into the mounting groove 8 to complete the assembly of the main crossbar 3, the secondary crossbar 4 and the first column 1 and the second column 2, thereby replacing the use of bolts and nuts in the prior art, thereby simplifying the assembly steps and improving the assembly efficiency.

[0035] like Figure 3 As shown, a first chamfer 21 is provided on the side wall of the groove opening of the mounting groove 8, and the transverse groove portion of the mounting groove 8 is tilted upward, and the tilt angle between the transverse groove portion of the mounting groove 8 and the horizontal direction is 15° to 30°.

[0036] By opening the first chamfer 21, the mounting block 7 can be more conveniently aligned with the notch of the mounting groove 8, thereby facilitating the pushing of the mounting block 7 and further improving the assembly efficiency; at the same time, the horizontal groove portion of the mounting groove 8 is tilted upward at 15° to 30°. When the mounting block 7 is pushed into the notch of the mounting groove 8, under the action of the gravity of the main cross bar 3 and the secondary cross bar 4, the mounting block 7 automatically slides into the vertical groove portion along the horizontal groove portion of the mounting groove 8, thereby improving the convenience of operation and further facilitating assembly.

[0037] Further Figure 1 , 5 As shown in Figure 6, multiple groups of vertical rod assemblies are arranged between the two cross bar assemblies.

[0038] The vertical rod assembly includes a main vertical rod 15 and a secondary vertical rod 16. A telescopic groove 17 is axially opened in the main vertical rod 15. The secondary vertical rod 16 is movably arranged in the telescopic groove 17. The other end of the secondary vertical rod 16 passes through the telescopic groove 17. One end of the secondary vertical rod 16 located in the telescopic groove 17 is also fixedly connected to a limiting block 18. Threaded columns 19 are fixedly connected to the ends of the main vertical rod 15 and the secondary vertical rod 16 that are away from each other. A plurality of threaded holes 20 are equidistantly opened on the peripheral side walls of the main cross bar 3 and the secondary cross bar 4 along the length direction. The threaded columns 19 are threadedly matched with the threaded holes 20.

[0039] After the main cross bar 3, the secondary cross bar 4 are assembled with the first column 1 and the second column 2, the main vertical bar 15 and the secondary vertical bar 16 are vertically placed between the upper and lower groups of cross bar assemblies, and the threaded columns 19 on the main vertical bar 15 and the secondary vertical bar 16 are aligned with the threaded holes 20 on the upper and lower main cross bars 3 or the upper and lower secondary cross bars 4, and then the main vertical bar 15 and the secondary vertical bar 16 are rotated, and the threaded columns 19 are screwed into the corresponding threaded holes 20 to complete the assembly of the main vertical bar 15 and the secondary vertical bar 16, thereby completing the assembly of the fence.

[0040] Anti-skid grooves 23 are vertically provided on the peripheral side walls of the main vertical rod 15 and the auxiliary vertical rod 16. The anti-skid grooves 23 can prevent slipping during the rotation of the main vertical rod 15 and the auxiliary vertical rod 16, thereby ensuring normal assembly of the main vertical rod 15 and the auxiliary vertical rod 16.

[0041] The above arrangement, by fixing threaded columns 19 on the main vertical rod 15 and the secondary vertical rod 16 respectively, and opening threaded holes 20 compatible with the threaded columns 19 on the main cross bar 3 and the secondary cross bar 4, the main vertical rod 15 and the secondary vertical rod 16 are assembled through the threaded cooperation between the threaded columns 19 and the threaded holes 20, which can further improve the assembly efficiency.

[0042] like Figure 1 , 7 As shown in , 8, a plurality of positioning grooves are also provided on the side walls around the main cross bar 3, and the plurality of positioning grooves are evenly distributed along the length direction of the main cross bar 3. The secondary cross bar groove 5 axially penetrates the plurality of positioning grooves, and a positioning block 9 is fixedly connected to one end of the secondary cross bar 4 close to the main cross bar 3, and the positioning block 9 is arranged in one of the positioning grooves.

[0043] By opening the positioning groove, after the total length of the secondary crossbar 4 and the main crossbar 3 is adjusted, the positioning block 9 can be inserted into the positioning groove, thereby improving the stability of the cooperation between the main crossbar 3 and the secondary crossbar 4, and then improving the overall stability of the fence.

[0044] Furthermore, the positioning groove is divided into a transition groove 10 and a center groove 11. The center groove 11 is coaxially arranged with the secondary cross bar groove 5, and the cross-sectional area of ​​the center groove 11 is larger than the cross-sectional area of ​​the secondary cross bar groove 5. One end of the transition groove 10 is connected with the center groove 11, and the other end of the transition groove 10 passes through the side wall of the main cross bar 3. The width of the transition groove 10 is the same as the width of the positioning block 9. Both side walls of the positioning block 9 are provided with spring block grooves 12, and spring blocks 13 are movably arranged in the spring block grooves 12. A spring 14 is fixedly connected between the spring block 13 and the spring block groove 12.

[0045] Align the lower end of the positioning block 9 with the notch of the transition groove 10, and press down the positioning block 9. During the pressing down process of the positioning block 9, the spring blocks 13 in the spring block grooves 12 on both sides of the positioning block 9 are squeezed by the side walls of the transition groove 10 and pressed into the spring block grooves 12. At this time, the spring 14 is in a compressed state. As the positioning block 9 continues to be pressed down, when the positioning block 9 passes through the transition groove 10 and enters the center groove 11, the spring block 13 loses the squeezing effect, and is then pushed out of the spring block groove 12 by the spring 14 and stuck in the center groove 11.

[0046] The above arrangement, through the arrangement of the spring blocks 13 on both sides of the positioning block 9, can further improve the stability of the cooperation between the main cross bar 3 and the secondary cross bar 4, and further improve the overall stability of the fence.

[0047] A second chamfer 22 is provided on the top side wall of the transition groove 10. The second chamfer 22 facilitates the alignment of the positioning block 9 and the transition groove 10, thereby embodying the convenience of operation during the fence assembly process.

[0048] As shown in the figure, a winding groove 24 is provided on the side wall of the first column 1 in the extension direction, and a rotating rod 25 is axially rotatably connected in the winding groove 24. A winding spring 26 is provided on the top of the winding groove 24. The inner end of the winding spring 26 is fixedly connected to the top side wall of the rotating rod 25, and the outer end of the winding spring 26 is fixedly connected to the inner side wall of the top of the winding groove 24. A wire mesh 27 is wound on the rotating rod 25, and a hook 28 is also fixedly connected to the free end of the wire mesh 27. A hook groove 29 adapted to the hook 28 is opened on the side wall of the second column 2.

[0049] After the fence is assembled, the wire mesh 27 is pulled out from the winding groove 24 on the first column 1, and the free end of the wire mesh 27 is fixed to the second column 2 by the hook 28. The setting of the wire mesh 27 can prevent obstacles from passing through the fence between the adjacent main vertical bars 15 and the secondary vertical bars 16, thereby enhancing the isolation effect of the fence and further improving the practicality of the fence.

[0050] Working principle: When assembling the fence, first adjust the total length of the main cross bar 3 and the secondary cross bar 4 by moving the position of the secondary cross bar 4 in the secondary cross bar groove 5 according to the needs, then place the first column 1 and the second column 2 on the horizontal plane, and place the side walls of the first column 1 and the second column 2 with the mounting groove 8 opposite to each other, then align the mounting block 7 on the adjusted main cross bar 3 with the wider part of the mounting groove 8 on the first column 1, align the mounting block 7 on the secondary cross bar 4 with the wider part of the mounting groove 8 on the second column 2, and push the mounting block 7 into the mounting groove 8. The mounting block 7 is inserted into the mounting groove 8 by the horizontal groove of the mounting groove 8. After the main cross bar 3 and the secondary cross bar 4 are assembled, the main cross bar 3, the secondary cross bar 4, the first column 1 and the second column 2 are assembled, and the main vertical bar 15 and the secondary vertical bar 16 are vertically placed between the upper and lower groups of cross bar assemblies, and the threaded columns 19 on the main vertical bar 15 and the secondary vertical bar 16 are aligned with the threaded holes 20 on the upper and lower main cross bars 3 or the upper and lower secondary cross bars 4, and then the main vertical bar 15 and the secondary vertical bar 16 are rotated, and the threaded columns 19 are screwed into the corresponding threaded holes 20 to complete the assembly of the main vertical bar 15 and the secondary vertical bar 16, and the assembly of the fence is completed.

[0051] Finally, it should be noted that the above are only preferred embodiments of the present invention and are 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 make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A municipal engineering assembled fence, comprising a first column (1) and a second column (2) vertically standing on a horizontal plane, characterized in that: Two groups of crossbar assemblies are arranged between the first column (1) and the second column (2), and the two groups of crossbar assemblies are arranged in an upper and lower position. The crossbar assembly comprises a main crossbar (3) and a secondary crossbar (4). The main crossbar (3) is axially provided with a secondary crossbar groove (5), and the secondary crossbar (4) is inserted into the secondary crossbar groove (5). The end surfaces of the main crossbar (3) and the secondary crossbar (4) that are away from each other are fixedly connected with a connecting block (6), and the other end surface of the connecting block (6) is fixedly connected with a mounting block (7). The side walls of the first column (1) and the second column (2) are both provided with an L-shaped mounting groove (8), the vertical groove part of the L-shaped mounting groove (8) is located below the horizontal groove part, and the cross section of the mounting groove (8) is a convex shape. The mounting block (7) is located in the wider part of the mounting groove (8), and the connecting block (6) is located in the narrower part of the mounting groove (8). A plurality of vertical rod assemblies are also arranged between the two crossbar assemblies.

2. A municipal engineering assembled fence according to claim 1, characterized in that: A plurality of positioning grooves are also provided on the peripheral side wall of the main cross bar (3), and the plurality of positioning grooves are equidistantly distributed along the length direction of the main cross bar (3). The secondary cross bar groove (5) axially penetrates the plurality of positioning grooves. A positioning block (9) is fixedly connected to one end of the secondary cross bar (4) close to the main cross bar (3), and the positioning block (9) is arranged in one of the positioning grooves.

3. A municipal engineering assembled fence according to claim 2, characterized in that: The positioning groove is divided into a transition groove (10) and a center groove (11). The center groove (11) is coaxially arranged with the secondary crossbar groove (5), and the cross-sectional area of ​​the center groove (11) is larger than the cross-sectional area of ​​the secondary crossbar groove (5). One end of the transition groove (10) is connected with the center groove (11), and the other end of the transition groove (10) passes through the side wall of the main crossbar (3). The width of the transition groove (10) is the same as the width of the positioning block (9). Both side walls of the positioning block (9) are provided with spring block grooves (12), and a spring block (13) is movably arranged in the spring block groove (12). A spring (14) is fixedly connected between the spring block (13) and the spring block groove (12).

4. The municipal engineering assembled fence according to claim 1, characterized in that: The vertical rod assembly comprises a main vertical rod (15) and a secondary vertical rod (16); a telescopic groove (17) is axially provided in the main vertical rod (15); the secondary vertical rod (16) is movably arranged in the telescopic groove (17); the other end of the secondary vertical rod (16) passes through the telescopic groove (17); one end of the secondary vertical rod (16) located in the telescopic groove (17) is also fixedly connected to a limit block (18); a threaded column (19) is fixedly connected to the ends of the main vertical rod (15) and the secondary vertical rod (16) that are away from each other; a plurality of threaded holes (20) are equidistantly provided on the peripheral side walls of the main cross bar (3) and the secondary cross bar (4) along the length direction; the threaded column (19) is threadedly matched with the threaded hole (20).

5. The municipal engineering assembled fence according to claim 1, characterized in that: A first chamfer (21) is provided on the side wall at the notch of the installation groove (8).

6. The municipal engineering assembled fence according to claim 5, characterized in that: The transverse groove portion of the installation groove (8) is arranged to be inclined upward, and the inclined angle between the transverse groove portion of the installation groove (8) and the horizontal direction is 15° to 30°.

7. The municipal engineering assembled fence according to claim 3, characterized in that: A second chamfer (22) is provided on the top side wall of the transition groove (10).

8. The municipal engineering assembled fence according to claim 4, characterized in that: Anti-slip grooves (23) are vertically provided on the peripheral side walls of the main vertical rod (15) and the auxiliary vertical rod (16).

9. The municipal engineering assembled fence according to claim 1, characterized in that: A winding groove (24) is provided on the side wall of the first column (1) in an extension direction, a rotating rod (25) is axially rotatably connected in the winding groove (24), a winding spring (26) is provided at the top of the winding groove (24), the inner end of the winding spring (26) is fixedly connected to the top side wall of the rotating rod (25), the outer end of the winding spring (26) is fixedly connected to the top inner side wall of the winding groove (24), a wire mesh (27) is wound on the rotating rod (25), a hook (28) is also fixedly connected to the free end of the wire mesh (27), and a hook groove (29) adapted to the hook (28) is provided on the side wall of the second column (2).

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