Push-out type sliding support hinge of parallel fork type and folding structure of parallel fork type

Abstract

The utility model provides a push-out type sliding support hinge of a parallel fork type structure and a folding structure thereof, the push-out type sliding support hinge comprises an opening and closing assembly, a sliding assembly, a limiting assembly and an adjusting assembly, the opening and closing assembly comprises a first bottom plate and a second bottom plate, and the first bottom plate and the second bottom plate are connected through the parallel fork type structure; the parallel fork-shaped structures are formed by sequentially connecting multiple sets of fork-shaped structures, non-connected connecting arms between the adjacent fork-shaped structures are arranged in parallel, and sliding assemblies, limiting assemblies and adjusting assemblies are sequentially arranged in the sliding grooves of the first bottom plate and the second bottom plate. According to the push-out type sliding support hinge, the parallel forks and the folding structures of the parallel forks are arranged, so that the push-out type sliding support hinge has a large opening stroke, and the stress distribution of the push-out type sliding support hinge is more reasonable.

Description

Technical Field

[0001] This application relates to the field of building door and window hardware technology, and in particular to a parallel fork-type push-out sliding hinge with a folding structure. Background Technology

[0002] Push-out sliding hinges, as a type of door and window hardware, are commonly used on casement windows to allow the window sash to open or close parallel to the normal direction of the facade. In the current technology, most of the push-out sliding hinges on the market are too large to be used in smaller or narrower casement windows. On the other hand, push-out sliding hinges with smaller opening strokes cannot provide good ventilation performance, and their small size also leads to low product safety. As a result, the practicality of narrower casement windows is greatly reduced due to low safety and poor ventilation performance. Utility Model Content

[0003] To at least partially solve the above problems, this application has optimized and designed the push-out sliding hinge structure. By setting the parallel fork type and its folding structure, it has a larger opening stroke and the force distribution of the push-out sliding hinge is more reasonable.

[0004] This application is achieved through the following technical solution:

[0005] A parallel fork-type and folding-structure push-out sliding hinge includes an opening and closing component, a sliding component, a limiting component, and an adjusting component.

[0006] The opening and closing assembly includes a first base plate and a second base plate, which are connected by a parallel fork-shaped structure. The parallel fork-shaped structure is formed by sequentially connecting multiple sets of fork-shaped structures, with non-connecting connecting arms between adjacent fork-shaped structures arranged in parallel.

[0007] The first base plate has a groove on one side and is fitted to the window sash on the other side. The second base plate has a groove on one side and is fitted to the window frame on the other side. The grooves on the first base plate face opposite directions to those on the second base plate.

[0008] The sliding components, limiting components, and adjusting components are sequentially provided in the sliding grooves of the first base plate and the second base plate.

[0009] In an optional embodiment, the opening and closing assembly further includes a first connecting arm, a second connecting arm, a third connecting arm, and a fourth connecting arm. The first connecting arm and the second connecting arm are rotatably connected to form a first fork-shaped structure, and the third connecting arm and the fourth connecting arm are rotatably connected to form a second fork-shaped structure. The first fork-shaped structure and the second fork-shaped structure are sequentially connected to form a double parallel fork-shaped structure. The first connecting arm and the third connecting arm are arranged in parallel, and the second connecting arm and the fourth connecting arm are arranged in parallel.

[0010] In one optional embodiment, the sliding assembly includes a first base plate slider, a first base plate bolt, a second base plate slider, and a second base plate bolt. One end of the first connecting arm is rotatably connected to the first base plate slider, and the other end of the first connecting arm is rotatably connected to one end of the fourth connecting arm. The other end of the fourth connecting arm is rotatably connected to the second base plate slider.

[0011] In one optional embodiment, the first base plate slider is slidably disposed in the groove of the first base plate, and the first base plate slider is provided with a first base plate bolt to increase the self-positioning force of the first base plate slider. The second base plate slider is slidably disposed in the groove of the second base plate, and the second base plate slider is provided with a second base plate bolt to increase the self-positioning force of the second base plate slider.

[0012] In an optional embodiment, the adjusting assembly includes a first base plate shim, a first eccentric rivet, a second base plate shim, and a second eccentric rivet. The first base plate shim is fixedly disposed at the end of the first base plate away from the first base plate slider. The second base plate shim is fixedly disposed at the end of the second base plate away from the second base plate slider. One end of the second connecting arm is rotatably connected to the first base plate shim via the first eccentric rivet. The other end of the second connecting arm is rotatably connected to one end of the third connecting arm. The other end of the third connecting arm is rotatably connected to the second base plate shim via the second eccentric rivet.

[0013] In one optional embodiment, the limiting component includes a first base plate limiting slider and a second base plate limiting slider. The first base plate limiting slider is positioned between the first base plate pad and the first base plate slider, and the second base plate limiting slider is positioned between the second base plate pad and the second base plate slider.

[0014] In an optional embodiment, the limiting component further includes a first base plate stop and a second base plate stop. The first base plate stop is fixedly provided in the first base plate limiting slider to limit the sliding stroke of the first base plate slider, and the second base plate stop is fixedly provided in the second base plate limiting slider to limit the sliding stroke of the second base plate slider.

[0015] In one optional embodiment, protrusions are provided in the grooves of the first base plate and the second base plate respectively to limit the maximum opening stroke of the hinge.

[0016] In one optional embodiment, the first connecting arm and the second connecting arm are riveted together by a first central rivet, and a first central washer is provided between the first connecting arm and the second connecting arm. The third connecting arm and the fourth connecting arm are riveted together by a second central rivet, and a second central washer is provided between the third connecting arm and the fourth connecting arm.

[0017] In one optional embodiment, the first connecting arm and the fourth connecting arm are riveted together by a third rivet, and a first gasket is provided between the first connecting arm and the fourth connecting arm. The second connecting arm and the third connecting arm are riveted together by a second rivet, and a second gasket is provided between the second connecting arm and the third connecting arm.

[0018] This application's technical solution utilizes a parallel fork-shaped structure to achieve a more even force distribution during practical applications, thus improving the safety and reliability of the push-out sliding hinge. Its foldable structure provides a larger opening stroke, meeting ventilation requirements in practical applications. The push-out sliding hinge of this application allows for parallel opening and closing of the hinge's components, adapting to parallel opening and closing actions when installed on sliding window profiles. During opening, the connecting arms gradually open from a parallel state, causing the two base plates to gradually move away. The sliders in the base plates gradually approach the center of the hinge until the hinge is opened to its maximum stroke position. At this point, the sliders on both base plates contact their respective base plate stops, which are fixed within the base plate limiting sliders. In practical applications, the base plate limiting sliders are fixed within the base plate grooves, preventing the base plate sliders from sliding further forward and limiting the hinge's maximum opening stroke.

[0019] The push-out sliding hinge of this application has a limiting component that can control the maximum opening stroke of the hinge. This function is mainly achieved through a bottom plate limiting slider and a bottom plate stop. The bottom plate limiting slider has holes that can be matched with the holes reserved in the bottom plate to fix it on the window sash profile, so as to freely control the maximum opening stroke.

[0020] The push-out sliding hinge of this application has a sliding component that enables smooth movement. The sliding component is located in the base plate groove. The first base plate slider and the first connecting arm are connected by the first rivet, and the second base plate slider and the fourth connecting arm are connected by the fourth rivet. This enables smooth parallel opening and closing when installed on a sliding window profile. The base plate slider has a plastic-coated design, meaning that the slider is made of stainless steel wrapped with a layer of high-performance plastic. The plastic-coated design can improve the service life and safety of the product. Even if the plastic fails due to factors such as fire, the internal stainless steel material can prevent the slider from detaching, avoiding window sash detachment and other risks. The base plate slider is equipped with a base plate bolt, and the self-positioning force of the hinge can be adjusted by rotating the base plate bolt.

[0021] The push-out sliding hinge of this application has a base plate washer made of stainless steel and fixed in the base plate groove, which can improve the strength of the base plate and enhance the safety and reliability of the product.

[0022] The push-out sliding hinge of this application has an adjustment component that can adjust the closing distance between the two base plates. The position of the base plate is controlled by rotating the eccentric rivet to meet the adjustment requirements of the sliding window, namely the sealing adjustment. This structure is not necessary. Even if this structure is not present, it can be replaced with ordinary rivets to meet the product installation and use, but the eccentric adjustment function will not be available. Attached Figure Description

[0023] 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 only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is an exploded view of the structure of Embodiment 1 of this application;

[0025] Figure 2 This is a schematic diagram of the open state in Embodiment 1 of this application;

[0026] Figure 3 This is a schematic diagram of the closed state in Embodiment 1 of this application;

[0027] Figure 4 This is a schematic diagram of the multi-forked folding structure of Embodiment 2 of this application;

[0028] 1-First base plate, 11-First base plate slider, 111-First base plate bolt, 12-First base plate limiting slider, 121-First base plate stop, 13-First base plate gasket;

[0029] 2-First connecting arm, 21-First rivet, 22-First center washer, 23-First washer;

[0030] 3-Second connecting arm, 31-Second washer, 32-First center rivet, 33-First eccentric rivet;

[0031] 4-Third connecting arm, 41-Second rivet, 42-Second center washer, 43-Second eccentric rivet;

[0032] 5-Fourth connecting arm, 51-Fourth rivet, 52-Second center rivet, 53-Third rivet;

[0033] 6-Second base plate, 61-Second base plate slider, 611-Second base plate bolt, 62-Second base plate limit slider, 621-Second base plate stop block, 63-Second base plate gasket. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] The main purpose of this application is to fill the technological gaps in existing products and provide a highly safe and reliable parallel fork-type and folding structure push-out sliding hinge.

[0036] The technical solution of this application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0037] This application provides a parallel fork-type and folding structure push-out sliding hinge, see [link to related document]. Figure 1-4 It includes opening and closing components, sliding components, limiting components, and adjusting components.

[0038] The opening and closing assembly includes a first base plate 1 and a second base plate 6. The first base plate 1 and the second base plate 6 are connected by a parallel fork-shaped structure. The parallel fork-shaped structure is formed by connecting multiple sets of fork-shaped structures in sequence, and the non-connecting connecting arms between adjacent fork-shaped structures are arranged in parallel.

[0039] One side of the first base plate 1 is provided with a sliding groove, and the other side is attached to the window sash. One side of the second base plate 6 is provided with a sliding groove, and the other side is attached to the window frame. The sliding groove of the first base plate 1 faces opposite directions to the sliding groove of the second base plate 6.

[0040] The sliding components, limiting components, and adjusting components are sequentially provided in the sliding grooves of the first base plate 1 and the second base plate 6.

[0041] In one embodiment provided in this application, the opening and closing assembly further includes a first connecting arm 2, a second connecting arm 3, a third connecting arm 4, and a fourth connecting arm 5. The first connecting arm 2 and the second connecting arm 3 are rotatably connected to form a first fork-shaped structure, and the third connecting arm 4 and the fourth connecting arm 5 are rotatably connected to form a second fork-shaped structure. The first fork-shaped structure and the second fork-shaped structure are sequentially connected to form a double parallel fork-shaped structure. The first connecting arm 2 and the third connecting arm 4 are arranged in parallel, and the second connecting arm 3 and the fourth connecting arm 5 are arranged in parallel.

[0042] In one embodiment provided in this application, the sliding assembly includes a first base plate slider 11, a first base plate bolt 111, a second base plate slider 61, and a second base plate bolt 611. One end of the first connecting arm 2 is rotatably connected to the first base plate slider 11, and the other end of the first connecting arm 2 is rotatably connected to one end of the fourth connecting arm 5. The other end of the fourth connecting arm 5 is rotatably connected to the second base plate slider 61.

[0043] In one embodiment provided in this application, a first base plate slider 11 is slidably disposed in a groove of the first base plate 1, and a first base plate bolt 111 is provided in the first base plate slider 11 to increase the self-positioning force of the first base plate slider 11. A second base plate slider 61 is slidably disposed in a groove of the second base plate 6, and a second base plate bolt 611 is provided in the second base plate slider 61 to increase the self-positioning force of the second base plate slider 61.

[0044] In one embodiment provided in this application, the adjustment assembly includes a first base plate shim 13, a first eccentric rivet 33, a second base plate shim 63, and a second eccentric rivet 43. The first base plate shim 13 is fixedly disposed at the end of the first base plate 1 away from the first base plate slider 11. The second base plate shim 63 is fixedly disposed at the end of the second base plate 6 away from the second base plate slider 61. One end of the second connecting arm 3 is rotatably connected to the first base plate shim 13 through the first eccentric rivet 33. The other end of the second connecting arm 3 is rotatably connected to one end of the third connecting arm 4. The other end of the third connecting arm 4 is rotatably connected to the second base plate shim 63 through the second eccentric rivet 43.

[0045] In one embodiment provided in this application, the closing distance between the two base plates of the hinge can be controlled by adjusting the eccentric rivet, which can thus meet the sealing adjustment of the sliding window in actual use.

[0046] In one embodiment provided in this application, the limiting component includes a first base plate limiting slider 12 and a second base plate limiting slider 62. The first base plate limiting slider 12 is limitedly disposed between the first base plate pad 13 and the first base plate slider 11, and the second base plate limiting slider 62 is limitedly disposed between the second base plate pad 63 and the second base plate slider 61.

[0047] In one embodiment provided in this application, the limiting component further includes a first base plate stop 121 and a second base plate stop 621. The first base plate stop 121 is fixedly provided in the first base plate limiting slider 12 to limit the sliding stroke of the first base plate slider 11, and the second base plate stop 621 is fixedly provided in the second base plate limiting slider 62 to limit the sliding stroke of the second base plate slider 61.

[0048] In one embodiment provided in this application, protrusions are respectively provided in the grooves of the first base plate 1 and the second base plate 6 to limit the maximum opening stroke of the hinge. Alternatively, the base plate limiting slider can be fixed to the base plate and the window sash profile with screws to limit the maximum opening stroke of the hinge.

[0049] In one embodiment provided in this application, the first connecting arm 2 and the second connecting arm 3 are riveted together by a first central rivet 32, and a first central washer 22 is provided between the first connecting arm 2 and the second connecting arm 3. The third connecting arm 4 and the fourth connecting arm 5 are riveted together by a second central rivet 52, and a second central washer 42 is provided between the third connecting arm 4 and the fourth connecting arm 5.

[0050] In one embodiment provided in this application, the first connecting arm 2 and the fourth connecting arm 5 are riveted together by a third rivet 53, and a first gasket 23 is provided between the first connecting arm 2 and the fourth connecting arm 5. The second connecting arm 3 and the third connecting arm 4 are riveted together by a second rivet 41, and a second gasket 31 is provided between the second connecting arm 3 and the third connecting arm 4.

[0051] In one embodiment provided in this application, a first base plate 1 has a first base plate limiting slider 12 and a first base plate slider 11 that can slide in the groove. A first base plate stop 121 is fixed in the first base plate limiting slider 12 to limit the sliding stroke of the first base plate slider 11. A first base plate bolt 111 is provided in the first base plate slider 11 to increase the self-positioning force of the first base plate slider 11. The first connecting arm 2 is riveted to the first base plate slider 11 by a first rivet 21. The second connecting arm 3 is riveted to the first base plate 1 by a first eccentric rivet 33, with a first base plate gasket 13 fixed in the middle. The second connecting arm 3 is riveted to the first connecting arm 2 by a first center rivet 32, with a first center gasket 22 in the middle. The third connecting arm 4 is riveted to the second connecting arm 3 by a second rivet 41, with a second gasket 31 in the middle. The fourth connecting arm 5 is riveted to the first connecting arm 2 by a third rivet 53, with a first gasket 2 in the middle. 3. The fourth connecting arm 5 is riveted to the third connecting arm 4 by the second central rivet 52, and a second central washer 42 is provided in the middle. The fourth connecting arm 5 is riveted to the second base plate slider 61 by the fourth rivet 51. The third connecting arm 4 is riveted to the second base plate 6 by the second eccentric rivet 43, and a second base plate washer 63 is fixed in the middle. The second base plate 6 has a second base plate limiting slider 62 and a second base plate slider 61 that can slide in the groove. The second base plate limiting slider 62 has a second base plate stop 621 fixed in it to limit the sliding stroke of the second base plate slider 61. The second base plate slider 61 has a second base plate bolt 611 in it to increase the self-positioning force of the second base plate slider 61. The above components are riveted together to form an opening and closing assembly to realize the parallel opening and closing of the hinge. In this embodiment, after being installed on the sliding window profile, the parallel opening and closing of the window sash can be realized, and the opening stroke of the window sash can be realized and limited.

[0052] In one embodiment provided in this application, the first eccentric rivet 33 rivets the first base plate 1 and the second connecting arm 3 together, and the second eccentric rivet 43 rivets the second base plate 6 and the third connecting arm 4 together. By rotating the corresponding eccentric rivet, the closing distance between the two base plates can be adjusted to meet the adjustment requirements of the sliding window, i.e., the sealing adjustment. This structure is not necessary. Even if this structure is not present, replacing it with ordinary rivets can still meet the product installation and use, but the eccentric adjustment function will not be available.

[0053] In one embodiment provided in this application, in the opening and closing assembly, the first connecting arm 2 is riveted to the second connecting arm 3 by a first central rivet 32, with a first central washer 22 in between, forming a fork-shaped structure. The third connecting arm 4 is riveted to the fourth connecting arm 5 by a second central rivet 52, with a second central washer 42 in between, forming a second fork-shaped structure. In the product structure, the fork shape can be increased from a double-fork folding structure to a multi-fork folding structure, such as... Figure 4 As shown, this is to achieve a larger opening stroke.

[0054] In one embodiment provided in this application, the installation process of the push-out sliding hinge is as follows:

[0055] Place the first base plate 1 on the reserved position of the window sash. First, screw in the fastening screws at the long oval holes at both ends of the first base plate 1. Then, after confirming that the hinge installation position is centered by measuring tools such as calipers, screw in the fastening screws at the mounting holes of the first base plate 1 in sequence to fix it. After determining the maximum opening stroke to be achieved, the first base plate limiting slider 12 is fixed in the relative position by screwing in the fastening screws.

[0056] Place the second base plate 6 on the reserved position of the window frame. First, screw in the fastening screws at the elongated holes at both ends of the second base plate 6. Then, after confirming that the hinge installation position is centered by measuring tools such as calipers, screw in the fastening screws at the mounting holes of the second base plate 6 in sequence to fix it. After determining the maximum opening stroke to be achieved, fix the second base plate limit slider 62 in the relative position by screwing in the fastening screws. Then close the window sash and observe whether the window sash is in the middle of the window frame. If it is in the middle position, the installation is complete.

[0057] Push-out sliding hinges need to be installed on the top, bottom, left, and right sides of the sliding window sash. The top and bottom are the guide sides, and the left and right sides are the load-bearing sides.

[0058] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A parallel fork type and its folding structure of push-out type sliding support hinge, characterized in that, The opening and closing assembly, sliding assembly, limiting assembly, adjusting assembly, The opening and closing assembly comprises a first bottom plate (1) and a second bottom plate (6), the first bottom plate (1) and the second bottom plate (6) are connected by parallel fork structures, the parallel fork structures are formed by a plurality of fork structures connected in sequence, and the non-connected connecting arms between adjacent fork structures are arranged in parallel, One side of the first bottom plate (1) is provided with a sliding groove, and the other side is attached to a sash, one side of the second bottom plate (6) is provided with a sliding groove, and the other side is attached to a window frame, the sliding groove of the first bottom plate (1) is opposite to the sliding groove of the second bottom plate (6), The sliding groove of the first bottom plate (1) and the second bottom plate (6) is sequentially provided with a sliding assembly, a limiting assembly and an adjusting assembly.

2. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 1, characterized in that, The opening and closing assembly further comprises a first connecting arm (2), a second connecting arm (3), a third connecting arm (4) and a fourth connecting arm (5), the first connecting arm (2) and the second connecting arm (3) are cross-rotatingly connected to form a first fork structure, the third connecting arm (4) and the fourth connecting arm (5) are cross-rotatingly connected to form a second fork structure, the first fork structure and the second fork structure are sequentially connected to form a double parallel fork structure, and the first connecting arm (2) and the third connecting arm (4) are arranged in parallel, and the second connecting arm (3) and the fourth connecting arm (5) are arranged in parallel.

3. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 2, characterized in that, The sliding assembly comprises a first bottom plate sliding block (11), a first bottom plate bolt (111), a second bottom plate sliding block (61) and a second bottom plate bolt (611), one end of the first connecting arm (2) is rotatably connected to the first bottom plate sliding block (11), the other end of the first connecting arm (2) is rotatably connected to one end of the fourth connecting arm (5), and the other end of the fourth connecting arm (5) is rotatably connected to the second bottom plate sliding block (61).

4. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 3, characterized in that, The first bottom plate sliding block (11) is slidably arranged in the sliding groove of the first bottom plate (1), the first bottom plate sliding block (11) is provided with a first bottom plate bolt (111) for increasing the self-positioning force of the first bottom plate sliding block (11), the second bottom plate sliding block (61) is slidably arranged in the sliding groove of the second bottom plate (6), and the second bottom plate sliding block (61) is provided with a second bottom plate bolt (611) for increasing the self-positioning force of the second bottom plate sliding block (61).

5. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 3, characterized in that, The adjusting assembly comprises a first bottom plate gasket (13), a first eccentric rivet (33), a second bottom plate gasket (63) and a second eccentric rivet (43), the first bottom plate gasket (13) is fixedly arranged at one end of the first bottom plate (1) away from the first bottom plate sliding block (11), the second bottom plate gasket (63) is fixedly arranged at one end of the second bottom plate (6) away from the second bottom plate sliding block (61), one end of the second connecting arm (3) is rotatably connected to the first bottom plate gasket (13) through the first eccentric rivet (33), the other end of the second connecting arm (3) is rotatably connected to one end of the third connecting arm (4), and the other end of the third connecting arm (4) is rotatably connected to the second bottom plate gasket (63) through the second eccentric rivet (43).

6. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 5, characterized in that, The limiting assembly comprises a first bottom plate limiting slider (12) and a second bottom plate limiting slider (62), the first bottom plate limiting slider (12) is arranged between the first bottom plate gasket (13) and the first bottom plate slider (11) in a limiting manner, and the second bottom plate limiting slider (62) is arranged between the second bottom plate gasket (63) and the second bottom plate slider (61) in a limiting manner.

7. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 6, characterized in that, The limiting assembly further comprises a first bottom plate stopper (121) and a second bottom plate stopper (621), the first bottom plate limiting slider (12) is fixedly provided with the first bottom plate stopper (121) for limiting the sliding stroke of the first bottom plate slider (11), and the second bottom plate limiting slider (62) is fixedly provided with the second bottom plate stopper (621) for limiting the sliding stroke of the second bottom plate slider (61).

8. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 6, characterized in that, The first bottom plate (1) and the second bottom plate (6) are respectively provided with convex points in the sliding grooves to limit the maximum opening stroke of the hinge.

9. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 2, characterized in that, The first connecting arm (2) and the second connecting arm (3) are riveted through a first center rivet (32), and the first connecting arm (2) and the second connecting arm (3) are provided with a first center gasket (22) therebetween; the third connecting arm (4) and the fourth connecting arm (5) are riveted through a second center rivet (52), and the third connecting arm (4) and the fourth connecting arm (5) are provided with a second center gasket (42) therebetween.

10. A parallel fork and its folding structure of push-out type sliding support hinge according to claim 5, characterized in that, The first connecting arm (2) and the fourth connecting arm (5) are riveted through a third rivet (53), and the first connecting arm (2) and the fourth connecting arm (5) are provided with a first gasket (23) therebetween; the second connecting arm (3) and the third connecting arm (4) are riveted through a second rivet (41), and the second connecting arm (3) and the third connecting arm (4) are provided with a second gasket (31) therebetween.

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