Joint device

Abstract

The utility model relates to the technical field of building block toys, and provides a joint device which comprises a first seat body, a second seat body arranged on the first seat body in a manner of rotating around a first axis, a first angle keeping mechanism used for keeping the second seat body at any one of a plurality of first rotating positions, and a first rotating table, and a second rotating table; the first rotating table is rotatably arranged on the first seat body around a second axis, and the second rotating table is rotatably arranged on the second seat body around a third axis; the first rotating table is provided with a first mounting position used for mounting building blocks, and / or the second rotating table is provided with a second mounting position used for mounting building blocks.

Description

Technical Field

[0001] The utility model belongs to the technical field of building block toys, and more specifically, relates to a joint device. Background Art

[0002] In modern toys (especially building blocks), it is often necessary to rotatably connect different modules. The way of rotatably connecting modules is usually to connect them through a rotating shaft, and the modules can rotate freely through the rotating shaft. However, in order to maintain the shape of the toy, sometimes it is necessary to keep the rotating position of the module at a certain rotation angle. However, the modules directly connected by the rotating shaft are usually free to rotate, and the relative rotation angle between the two modules cannot be kept stable. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a joint device to solve the technical problem that the relative rotation angle cannot be maintained when two modules are rotatably connected by a rotating shaft in the prior art.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is: providing a joint device, including: a first seat body, a second seat body rotatably arranged on the first seat body around a first axis, a first angle maintaining mechanism for maintaining the second seat body at any one of a plurality of first rotation positions, a first rotating table, and a second rotating table; the first rotating table is rotatably arranged on the first seat body around a second axis, and the second rotating table is rotatably arranged on the second seat body around a third axis; a first installation position for installing building blocks is arranged on the first rotating table, and / or a second installation position for installing building blocks is arranged on the second rotating table.

[0005] Further, the first axis is perpendicular to the second axis; and / or the first axis is perpendicular to the third axis.

[0006] Further, the first angle maintaining mechanism includes: a first assembly hole opened on the second seat body, a first shaft body arranged on the first seat body and passing through the first assembly hole, a sleeve connected to the second seat body and sleeved on the first shaft body, a ring body connected to the first seat body and sleeved outside the sleeve, a plurality of first recesses arranged on the outer side wall of the sleeve and surrounding the sleeve, and elastic pieces arranged on the inner wall of the ring body and capable of being clamped into the first recesses; the axis of the first shaft body is the first axis; when the second seat body rotates to any one of the first rotation positions, the elastic piece is clamped into one of the first recesses; the plurality of first rotation positions correspond to the plurality of first recesses one by one.

[0007] Further, the number of the elastic pieces is multiple.

[0008] Further, the ring body is detachably connected to the first base body.

[0009] Further, it further includes: a card slot opened on the first base body and extending along the extending direction of the first axis, a card-in part arranged on the ring body and carded into the card slot, and a first buckle arranged on the first shaft body and hooked on the edge of the first assembly hole; the ring body is clamped between the first base body and the second base body.

[0010] Further, it further includes: a second angle holding mechanism for holding the first rotating table at any one of a plurality of second rotating positions.

[0011] Further, the second angle holding mechanism includes: a second assembly hole opened on the first rotating table, a second shaft body arranged on the first base body and passing through the second assembly hole, a plurality of second recessed parts arranged on the inner wall of the second assembly hole along the circumferential direction of the second assembly hole, and a first protruding part arranged on the outer wall of the second shaft body and capable of being carded into or sliding out of the second recessed part; the axis of the second shaft body is the second axis; when the first rotating table rotates to any one of the second rotating positions, the first protruding part is carded into one of the second recessed parts; the plurality of second rotating positions correspond to the plurality of second recessed parts one by one.

[0012] Further, it further includes: a third angle holding mechanism for holding the second rotating table at any one of a plurality of third rotating positions.

[0013] Further, the third angle holding mechanism includes: a third assembly hole opened on the second rotating table, a third shaft body arranged on the second base body and passing through the third assembly hole, a plurality of third recessed parts arranged on the inner wall of the third assembly hole along the circumferential direction of the third assembly hole, and a second protruding part arranged on the outer wall of the third shaft body and capable of being carded into or sliding out of the third recessed part; the axis of the third shaft body is the third axis; when the second rotating table rotates to any one of the third rotating positions, the second protruding part is carded into one of the third recessed parts; the plurality of third rotating positions correspond to the plurality of third recessed parts one by one.

[0014] The beneficial effects of the joint device provided by the present utility model are as follows: Compared with the prior art, for the joint device provided by the present utility model, the second seat body is rotatably arranged on the first seat body around the first axis, that is, the second seat body can rotate relative to the first seat body around the first axis; the second seat body can rotate to multiple first rotation positions, and the first angle maintaining mechanism can hold the second seat body at any one of the first rotation positions. After the user rotates the second seat body to the required first rotation position, the second seat body can be held at this first rotation position by the first angle maintaining mechanism, avoiding random rotation of the second seat body; the first rotating table is rotatably arranged on the first seat body around the second axis, that is, the first rotating table can rotate relative to the first seat body around the second axis; a first installation position is arranged on the first rotating table, and building blocks can be installed at the first installation position. After the building blocks are installed at the first installation position, the building blocks can rotate around the second axis through the first rotating table; the second rotating table is rotatably arranged on the second seat body around the third axis, that is, the second rotating table can rotate relative to the second seat body around the third axis; a second installation position is arranged on the second rotating table, and building blocks can be installed at the second installation position. After the building blocks are installed at the second installation position, the building blocks can rotate around the third axis through the second rotating table; that is to say, after the building blocks are arranged at the first installation position of the first rotating table, the building blocks can rotate around the second axis (and / or the first axis) to achieve multi-degree-of-freedom rotation. After the first angle maintaining mechanism holds the second seat body at one of the first rotation positions, it can prevent the building blocks from continuing to rotate around the first axis; similarly, after the building blocks are arranged at the second installation position of the second rotating table, the building blocks can rotate around the third axis (and / or the first axis) to achieve multi-degree-of-freedom rotation. After the first angle maintaining mechanism holds the second seat body at one of the first rotation positions, it can prevent the building blocks from continuing to rotate around the first axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 A three-dimensional schematic diagram of the joint device provided by the embodiment of the present utility model in plug-in cooperation with building blocks;

[0017] Figure 2 A three-dimensional schematic diagram of the separation of the joint device provided by the embodiment of the present utility model from the building blocks;

[0018] Figure 3 A three-dimensional schematic diagram of the building blocks provided by the embodiment of the present utility model;

[0019] Figure 4Schematic perspective view of the first seat body provided by the embodiment of the present utility model Figure 1 ;

[0020] Figure 5 Schematic perspective view of the first seat body provided by the embodiment of the present utility model Figure 2 ;

[0021] Figure 6 Schematic perspective view of the ring body provided by the embodiment of the present utility model;

[0022] Figure 7 Schematic perspective view of the ring body and the first seat body before cooperation provided by the embodiment of the present utility model;

[0023] Figure 8 Schematic perspective view of the ring body and the first seat body after cooperation provided by the embodiment of the present utility model;

[0024] Figure 9 Schematic perspective view of the second seat body provided by the embodiment of the present utility model Figure 1 ;

[0025] Figure 10 Schematic perspective view of the second seat body provided by the embodiment of the present utility model Figure 2 ;

[0026] Figure 11 Schematic perspective view of the first seat body, the ring body and the second seat body before cooperation provided by the embodiment of the present utility model;

[0027] Figure 12 Schematic perspective view of the first seat body, the ring body and the second seat body after cooperation provided by the embodiment of the present utility model;

[0028] Figure 13 Schematic perspective view of the ring body and the second seat body after cooperation provided by the embodiment of the present utility model;

[0029] Figure 14 Schematic perspective view of the first rotating platform provided by the embodiment of the present utility model;

[0030] Figure 15 Schematic perspective view of the joint device and the first rotating platform and the second rotating platform before cooperation provided by the embodiment of the present utility model.

[0031] Among them, the reference numerals in the figure:

[0032] 11 - First body; 111 - Card slot; 12 - First shaft body; 121 - First buckle; 13 - Second shaft body; 131 - First protrusion; 132 - Second buckle; 21 - Second body; 211 - First assembly hole; 22 - Sleeve; 221 - First depression; 23 - Third shaft body; 231 - Second protrusion; 232 - Third buckle; 31 - Ring body; 311 - Insertion part; 32 - Elastic piece; 4 - First rotating table; 41 - Second assembly hole; 411 - Second depression; 5 - Second rotating table; 51 - Third assembly hole; 511 - Third depression; 61 - First installation position; 62 - Second installation position; 7 - Building block; 71 - First positioning hole. Detailed implementation mode

[0033] It should be noted that the specific embodiments are only used to explain the present invention and are not used to limit the present invention.

[0034] It should be noted that in the description of the embodiments of the present application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B; herein, "and / or" is only a description of the relationship between related objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. Among them, A and B can be singular or plural respectively.

[0035] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" or "connected at" another element, it can be directly connected to the other element or indirectly connected to the other element. When an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element.

[0036] It should be noted that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0037] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0038] It should be noted that the term "a plurality of" means two or more, unless otherwise specifically defined.

[0039] Please refer to Figures 1 to 15 together. Now, the joint device provided by the present utility model will be described. The joint device includes: a first base body 11, a second base body 21 rotatably arranged on the first base body 11 around a first axis, a first angle holding mechanism for holding the second base body 21 at any one of a plurality of first rotation positions, a first rotating table 4, and a second rotating table 5; the first rotating table 4 is rotatably arranged on the first base body 11 around a second axis, and the second rotating table 5 is rotatably arranged on the second base body 21 around a third axis; a first mounting position 61 for mounting a building block 7 is provided on the first rotating table 4, and / or a second mounting position 62 for mounting the building block 7 is provided on the second rotating table 5.

[0040] In this way, the second base body 21 is rotatably arranged on the first base body 11 around the first axis, that is, the second base body 21 can rotate relative to the first base body 11 around the first axis; the second base body 21 can rotate to a plurality of first rotation positions, and the first angle holding mechanism can hold the second base body 21 at any one of the first rotation positions, facilitating the user to rotate the second base body 21 to the required first rotation position, and then the second base body 21 can be held at the first rotation position by the first angle holding mechanism, avoiding the random rotation of the second base body 21; the first rotating table 4 is rotatably arranged on the first base body 11 around the second axis, that is, the first rotating table 4 can rotate relative to the first base body 11 around the second axis; a first mounting position 61 is provided on the first rotating table 4, and the building block 7 can be mounted on the first mounting position 61. After the building block 7 is mounted on the first mounting position 61, the building block 7 can rotate around the second axis through the first rotating table 4; the second rotating table 5 is rotatably arranged on the second base body 21 around the third axis, that is, the second rotating table 5 can rotate relative to the second base body 21 around the third axis; a second mounting position 62 is provided on the second rotating table 5, and the building block 7 can be mounted on the second mounting position 62. After the building block 7 is mounted on the second mounting position 62, the building block 7 can rotate around the third axis through the second rotating table 5; that is to say, after the building block 7 is arranged on the first mounting position 61 of the first rotating table 4, the building block 7 can rotate around the second axis (and / or the first axis) to realize multi-degree-of-freedom rotation, and the first angle holding mechanism can avoid the building block 7 from continuing to rotate around the first axis after holding the second base body 21 at one of the first rotation positions; similarly, after the building block 7 is arranged on the second mounting position 62 of the second rotating table 5, the building block 7 can rotate around the third axis (and / or the first axis) to realize multi-degree-of-freedom rotation, and the first angle holding mechanism can avoid the building block 7 from continuing to rotate around the first axis after holding the second base body 21 at one of the first rotation positions.

[0041] In one embodiment, the first mounting position 61 includes: a first positioning post provided on the first rotating table 4. Thus, a first positioning hole 71 can be provided on the building block 7, and the first positioning post can be inserted into the first positioning hole 71.

[0042] In one embodiment, the first mounting position 61 includes: a first mounting surface on the first rotating table 4, and the building block 7 can be bonded or fixed to the first mounting surface by fasteners.

[0043] In one embodiment, the second mounting position 62 includes: a second positioning post provided on the second rotating table 5. Thus, a second positioning hole can be provided on the building block 7, and the second positioning post can be inserted into the second positioning hole.

[0044] In one embodiment, the second mounting position 62 includes: a second mounting surface on the second rotating table 5, and the building block 7 can be bonded or fixed to the second mounting surface by fasteners.

[0045] In one embodiment, the first angle maintaining mechanism is connected to the first base 11 and the second base 21.

[0046] In one embodiment, the first angle maintaining mechanism is connected to the first base 11.

[0047] In one embodiment, the first angle maintaining mechanism is connected to the second base 21.

[0048] Further, please refer to Figures 1 to 15 , as a specific embodiment of the joint device provided by the present utility model, the first axis is perpendicular to the second axis; and / or the first axis is perpendicular to the third axis.

[0049] Further, please refer to Figures 1 to 15, as a specific embodiment of the joint device provided by the present utility model, the first angle maintaining mechanism includes: a first assembly hole 211 formed in the second seat body 21, a first shaft body 12 provided on the first seat body 11 and passing through the first assembly hole 211, a sleeve 22 connected to the second seat body 21 and sleeved on the first shaft body 12, a ring body 31 connected to the first seat body 11 and sleeved outside the sleeve 22, a plurality of first recessed portions 221 provided on the outer sidewall of the sleeve 22 and arranged around the sleeve 22, and an elastic piece 32 provided on the inner wall of the ring body 31 and capable of being clamped into the first recessed portion 221; the axis of the first shaft body 12 is the first axis; when the second seat body 21 rotates to any first rotation position, the elastic piece 32 is clamped in one of the first recessed portions 221; the plurality of first rotation positions correspond to the plurality of first recessed portions 221 one by one. In this way, the first shaft body 12 on the first seat body 11 passes through the first assembly hole 211 on the second seat body 21, and the sleeve 22 on the second seat body 21 is sleeved on the first shaft body 12, facilitating the rotation of the second seat body 21 around the first shaft body 12; the ring body 31 sleeved outside the sleeve 22 is provided on the first seat body 11, and the elastic piece 32 is provided on the inner wall of the ring body 31. The elastic piece 32 can be clamped in any one of the first recessed portions 221. When the elastic piece 32 is clamped into the first recessed portion 221, the first seat body 11 and the second seat body 21 can be maintained at this relative rotation angle; when the second seat body 21 (such as when the user pushes) continues to rotate against the resistance of the elastic piece 32 in the first recessed portion 221, the elastic piece 32 can slide into other first recessed portions 211 to keep the second seat body 21 at another first rotation position.

[0050] Further, please refer to Figures 1 to 15 , as a specific embodiment of the joint device provided by the present utility model, the number of the elastic pieces 32 is multiple.

[0051] Further, please refer to Figures 1 to 15 , as a specific embodiment of the joint device provided by the present utility model, the ring body 31 is detachably connected to the first seat body 11. In this way, it is convenient for the installation and disassembly of the ring body 31.

[0052] Further, please refer to Figures 1 to 15, as a specific implementation of the joint device provided by the present utility model, further includes: a card slot 111 opened on the first base 11 and extending along the extension direction of the first axis, a card-in part 311 provided on the ring body 31 and snapped into the card slot 111, and a first buckle 121 provided on the first shaft body 12 and hooked on the edge of the first assembly hole 211; the ring body 31 is clamped between the first base 11 and the second base 21. In this way, after the card-in part 311 on the ring body 31 is snapped into the card slot 111 of the first base 11, the connection between the first base 11 and the ring body 31 can be realized very conveniently; between the first base 11 and the second base 21 of the ring body 31, the position of the ring body 31 is more stable.

[0053] Further, please refer to Figures 1 to 15 , as a specific implementation of the joint device provided by the present utility model, further includes: a second angle holding mechanism for holding the first rotating table 4 at any one of a plurality of second rotation positions. In this way, the first rotating table 4 is held at any one of a plurality of second rotation positions by the second angle holding mechanism.

[0054] In one embodiment, the second angle holding mechanism is connected to the first rotating table 4 and the first base 11.

[0055] In one embodiment, the second angle holding mechanism is connected to the first rotating table 4.

[0056] In one embodiment, the second angle holding mechanism is connected to the first base 11.

[0057] Further, please refer to Figures 1 to 15, as a specific embodiment of the joint device provided by the present utility model, the second angle maintaining mechanism includes: a second assembly hole 41 opened on the first rotating table 4, a second shaft body 13 disposed on the first seat body 11 and passing through the second assembly hole 41, a plurality of second recessed portions 411 disposed on the inner wall of the second assembly hole 41 along the circumferential direction of the second assembly hole 41, and a first protruding portion 131 disposed on the outer wall of the second shaft body 13 and capable of being snapped into or slid out of the second recessed portion 411; the axis of the second shaft body 13 is the second axis; when the first rotating table 4 rotates to any second rotation position, the first protruding portion 131 is snapped into one of the second recessed portions 411; the plurality of second rotation positions correspond to the plurality of second recessed portions 411 one by one. Thus, the second shaft body 13 on the first seat body 11 passes through the second assembly hole 41 on the first rotating table 4, so that the first rotating table 4 can rotate around the second shaft body 13; the axis of the second shaft body 13 is the second axis, that is, the first rotating table 4 can rotate relative to the first seat body 11 around the second axis; there are a plurality of second recessed portions 411 on the inner wall of the second assembly hole 41, and the plurality of second recessed portions 411 are arranged along the circumferential direction of the second assembly hole 41; during the process of the first rotating table 4 rotating around the second shaft body 13, the first protruding portion 131 can be snapped into or slid out of the second recessed portion 411; the plurality of second rotation positions and the plurality of second recessed portions 411 correspond to each other one by one. When the user needs to rotate to one of the second rotation positions, only need to slide the first protruding portion 131 into the corresponding second recessed portion 411.

[0058] In one embodiment, it further includes: a second buckle 132 disposed on the second shaft body 13 and hooked to the edge of the second assembly hole 41.

[0059] Further, please refer to Figures 1 to 15 , as a specific embodiment of the joint device provided by the present utility model, it further includes: a third angle maintaining mechanism for maintaining the second rotating table 5 at any one of a plurality of third rotation positions. Thus, the second rotating table 5 is maintained at any one of the plurality of second rotation positions by the third angle maintaining mechanism.

[0060] In one embodiment, the third angle maintaining mechanism is connected between the second rotating table 5 and the second seat body 21.

[0061] In one embodiment, the third angle maintaining mechanism is connected to the second rotating table 5.

[0062] In one embodiment, the third angle maintaining mechanism is connected to the second seat body 21.

[0063] Further, please refer to Figures 1 to 15, as a specific embodiment of the joint device provided by the present utility model, the third angle maintaining mechanism includes: a third assembly hole 51 formed in the second rotating table 5, a third shaft body 23 disposed on the second seat body 21 and passing through the third assembly hole 51, a plurality of third recessed portions 511 disposed along the circumferential direction of the third assembly hole 51 on the inner wall of the third assembly hole 51, and a second protrusion 231 disposed on the outer wall of the third shaft body 23 and capable of being engaged with or sliding out of the third recessed portions 511; the axis of the third shaft body 23 is the third axis; when the second rotating table 5 rotates to any third rotation position, the second protrusion 231 is engaged in one of the third recessed portions 511; the plurality of third rotation positions correspond to the plurality of third recessed portions 511 one by one. Thus, the third shaft body 23 on the second seat body 21 passes through the third assembly hole 51 on the second rotating table 5, so that the second rotating table 5 can rotate around the third shaft body 23; the axis of the third shaft body 23 is the third axis, that is, the second rotating table 5 can rotate relative to the second seat body 21 around the third axis; there are a plurality of third recessed portions 511 on the inner wall of the third assembly hole 51, and the plurality of third recessed portions 511 are arranged along the circumferential direction of the third assembly hole 51; during the process of the second rotating table 5 rotating around the third shaft body 23, the first protrusion 131 can be engaged with or slide out of the third recessed portions 511; the plurality of third rotation positions and the plurality of third recessed portions 511 correspond to each other one by one. When the user needs to rotate to one of the third rotation positions, only need to slide the first protrusion 131 into the corresponding third recessed portion 511.

[0064] In one embodiment, it further includes: a third buckle 232 disposed on the third shaft body 23 and hooked on the edge of the third assembly hole 51.

[0065] The above is only the preferred embodiment of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present utility model, several improvements and replacements can still be made, and these improvements and replacements should also be regarded as the protection scope of the present utility model.

Claims

1. An articular device, characterized in that, Including: A first base body, a second base body rotatably arranged on the first base body around a first axis, a first angle holding mechanism for holding the second base body at any one of a plurality of first rotation positions, a first turntable, and a second turntable; the first turntable is rotatably arranged on the first base body around a second axis, and the second turntable is rotatably arranged on the second base body around a third axis; a first installation position for installing building blocks is arranged on the first turntable, and / or a second installation position for installing building blocks is arranged on the second turntable.

2. The joint device according to claim 1, wherein The first axis is perpendicular to the second axis; and / or the first axis is perpendicular to the third axis.

3. The joint device according to claim 1, characterized in that, The first angle holding mechanism includes: a first assembly hole opened on the second base body, a first shaft body arranged on the first base body and passing through the first assembly hole, a sleeve connected to the second base body and sleeved on the first shaft body, a ring body connected to the first base body and sleeved outside the sleeve, a plurality of first recesses arranged on the outer side wall of the sleeve and surrounding the sleeve, and elastic pieces arranged on the inner wall of the ring body and capable of being snapped into the first recesses; the axis of the first shaft body is the first axis; when the second base body rotates to any one of the first rotation positions, the elastic piece is snapped into one of the first recesses; the plurality of first rotation positions correspond to the plurality of first recesses one by one.

4. The joint device according to claim 3, characterized in that, The number of the elastic pieces is plural.

5. The articulation device according to claim 3, wherein, The ring body is detachably connected to the first base body.

6. The joint device according to claim 5, characterized in that, Further including: A card slot opened on the first base body and extending along the extending direction of the first axis, a card-in part arranged on the ring body and snapped into the card slot, and a first buckle arranged on the first shaft body and hooking the edge of the first assembly hole; the ring body is clamped between the first base body and the second base body.

7. The joint device according to claim 1, characterized in that, Further including: A second angle holding mechanism for holding the first turntable at any one of a plurality of second rotation positions.

8. The articulation device according to claim 7, characterized in that, The second angle holding mechanism includes: a second assembly hole opened on the first turntable, a second shaft body arranged on the first base body and passing through the second assembly hole, a plurality of second recesses arranged on the inner wall of the second assembly hole along the circumferential direction of the second assembly hole, and a first protrusion arranged on the outer wall of the second shaft body and capable of being snapped into or sliding out of the second recesses; the axis of the second shaft body is the second axis; when the first turntable rotates to any one of the second rotation positions, the first protrusion is snapped into one of the second recesses; the plurality of second rotation positions correspond to the plurality of second recesses one by one.

9. The joint device according to claim 1, characterized in that, Further including: A third angle holding mechanism for holding the second turntable at any one of a plurality of third rotation positions.

10. The joint device according to claim 9, wherein, The third angle maintaining mechanism includes: a third assembly hole formed in the second rotating table, a third shaft body disposed on the second seat body and passing through the third assembly hole, a plurality of third recessed portions disposed on the inner wall of the third assembly hole along the circumferential direction of the third assembly hole, and a second protruding portion disposed on the outer wall of the third shaft body and capable of being engaged with or sliding out of the third recessed portion; the axis of the third shaft body is the third axis; when the second rotating table rotates to any of the third rotation positions, the second protruding portion is engaged in one of the third recessed portions; the plurality of third rotation positions correspond to the plurality of third recessed portions one by one.

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