Folding joint structure

By designing the locking mechanism and limiting parts in the folded joint structure of children's utensils, and using the unlocking parts to achieve locking and unlocking, the problems of complex structure and inconvenient operation in the prior art are solved, and the effects of simplified structure, simple operation and one-hand unlocking are achieved.

CN222997656UActive Publication Date: 2025-06-20KUNSHAN VIGORKIDS CHILD PROD
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202422207741.9
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-09-10
Publication Date
2025-06-20
Estimated Expiration
2034-09-10

AI Technical Summary

Technical Problem

The folding joints in existing children's utensils have complex structures, high generation costs, inconvenient folding operation, and one-hand unlocking cannot be achieved.

Method used

A folding joint structure including a first connector, a second connector and a third connector of a rotating connection is designed. By setting a locking mechanism between the first connector and the second connector, and installing a limiting member at the rotating connection of the third connector, the unlocking member is used to drive the axial movement of the limiting member to realize unlocking between the locking mechanism and the limiting member.

Benefits of technology

It realizes structure simplification, reduces generation costs, makes folding operation easier and faster, and can achieve one-hand unlocking.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN222997656U_ABST
    Figure CN222997656U_ABST
Patent Text Reader

Abstract

The utility model discloses a folding joint structure which comprises a first connecting piece, a second connecting piece and a third connecting piece which are connected in a rotating mode, a locking mechanism is arranged between the first connecting piece and the second connecting piece, and a limiting piece which can move in the axial direction relative to the third connecting piece and cannot rotate relative to the third connecting piece is installed at the rotating position of the third connecting piece. The limiting piece is movably connected with the locking mechanism, whether the limiting piece is locked by the locking mechanism or not can be achieved by changing the axial distance between the limiting piece and the locking mechanism, and the third connecting piece is provided with an unlocking piece capable of pushing the limiting piece to move axially; when the folding joint is unfolded for use, limiting and locking of the third connecting piece can be relieved independently through the unlocking piece, so that whether the third connecting piece is opened or not and the opening angle are adjusted; when the folding joint is folded, limiting locking of the third connecting piece can be synchronously relieved when the locking mechanism is unlocked, unlocking of the whole folding joint can be achieved without additional operation of an unlocking piece, and due to the design, folding operation is simpler, more convenient and faster, and single-hand unlocking can be achieved.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The utility model relates to children's utensils, in particular to a folding joint structure for children's utensils. Background Art

[0002] In the prior art, the folding joint structures used in children's utensils (such as children's bassinets, baby strollers, etc.) generally include a first connecting member, a second connecting member and a third connecting member which are rotatably connected. When the children's utensils are unfolded and locked, basically the first connecting member, the second connecting member and the third connecting member are kept in the unfolded state and none of them can rotate; if one of them needs to be rotationally adjusted when the other two are unfolded and locked, usually two locking mechanisms need to be provided, and there is no linkage between the two locking mechanisms. This not only makes the overall structure relatively complex, increases the production cost, but also makes the folding operation inconvenient. It is necessary to unlock different locking mechanisms in sequence and cannot achieve one-handed unlocking and folding. Summary of the Invention

[0003] The purpose of the utility model is to provide a folding joint structure with novel structure and convenient operation.

[0004] The technical solution of the utility model is: a folding joint structure, including a first connecting member, a second connecting member and a third connecting member which are rotatably connected. A locking mechanism is provided between the first connecting member and the second connecting member to lock them when they are in the unfolded position. A limiting member which can move axially relative to the rotational connection of the third connecting member and cannot rotate relative to it is installed at the rotational connection of the third connecting member. The limiting member is movably connected with the locking mechanism, and the locking or unlocking of the locking mechanism to the limiting member can be realized by changing the axial distance between the two. An unlocking member which can be pressed and can push the limiting member to move axially is provided on the third connecting member;

[0005] When the folding joint is in the unfolded and in-use state, the first connecting member and the second connecting member are unfolded and locked by the locking mechanism, and the limiting member and the locking mechanism are limit-locked. At this time, the third connecting member is kept in the unfolded position and cannot rotate relative to the unfolded first connecting member and second connecting member;

[0006] When the third connecting member needs to rotate, the unlocking between the locking mechanism and the limiting member can be realized by driving the limiting member to axially displace through the unlocking member or by the axial displacement of the locking mechanism relative to the limiting member when the locking mechanism is unlocked. At this time, the third connecting member can rotate freely.

[0007] As a preferred technical solution, the locking mechanism includes a gear that can be simultaneously locked into the first tooth groove of the first connecting member and the second tooth groove of the second connecting member, and an unlocking mechanism that can drive the gear to move axially. The unlocking mechanism drives the gear to move axially so that the gear exits the first tooth groove and completely enters the second tooth groove to release the locking of the first connecting member and the second connecting member.

[0008] As a preferred technical solution, the rotational connection points of the first connecting member, the second connecting member, and the third connecting member are coaxially rotationally connected in sequence from inside to outside, and the gear and the limiting member are coaxially arranged with the above three; a first spring, a spacer, and a second spring are coaxially arranged in sequence between the gear and the limiting member; the outer end of the limiting member is an outer limiting portion with a plurality of convex teeth evenly spaced on the outer circumference, and the inner end of the limiting member is an inner limiting portion with a plurality of convex teeth spaced on the outer circumference. The lower end of the third connecting member has a third tooth groove for the outer limiting portion to be inserted and move axially. One side of the gear close to the limiting member has a fourth tooth groove corresponding to the inner limiting portion, and the middle of the gear has an activity groove communicating with the fourth tooth groove and allowing the inner limiting portion to rotate.

[0009] When the third connecting member is in the locked and limited state, the outer end of its limiting member is limited by the cooperation of the outer limiting portion and the third tooth groove of the third connecting member, and the inner end of its limiting member is limited by the cooperation of the inner limiting portion and the fourth tooth groove of the gear; when the third connecting member needs to rotate, the limiting member can be driven to move axially inward by the unlocking member or the gear can move axially outward when the locking mechanism is unlocked, releasing the limitation on the third connecting member. At this time, the third connecting member can rotate freely.

[0010] As a preferred technical solution, the unlocking mechanism includes a linkage block coaxially arranged with the gear and capable of axial movement, and an unlocking block arranged in the first tooth groove and capable of radial sliding relative thereto. The unlocking block is in inclined surface cooperation with the linkage block. An unlocking operation assembly is provided on the first connecting member. The unlocking operation assembly is connected to the unlocking block through a traction cable and can drive the unlocking block to slide. When the unlocking block slides along the unlocking direction, it drives the linkage block to move axially through inclined surface cooperation. The linkage block pushes the gear and makes the gear exit the first tooth groove and completely enter the second tooth groove to release the locking of the first connecting member and the second connecting member.

[0011] As a preferred technical solution, the limiting member includes a cylindrical portion. The inner limiting portion is formed at the inner end of the cylindrical portion. The outer limiting portion is formed at the outer end of the cylindrical portion, and its outer diameter is larger than the outer diameter of the inner limiting portion, and its inner diameter is smaller than the inner diameter of the cylindrical portion.

[0012] As a preferred technical solution, the first spring, the spacer and the second spring are arranged inside the cylindrical part of the limiting member. One end of the first spring abuts against the gear, and the other end abuts against the inner side surface of the spacer. One end of the second spring abuts against the outer side surface of the spacer, and the other end abuts against the inner side surface of the outer limiting part.

[0013] As a preferred technical solution, the unlocking member is an unlocking button. There is a button groove for installing the unlocking member at the rotational connection of the third connecting member. The outer end of the unlocking member is exposed to form a pressing part, and the inner side of the unlocking member has an axially extending extension barb that extends into the third tooth groove; when pressing the unlocking member, its extension barb squeezes inward and pushes the limiting member to move axially inward.

[0014] As a preferred technical solution, the unlocking operation assembly is a rotating unlocking handle assembly or a pressing unlocking assembly.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] When the third connecting member in the present utility model needs to rotate, the unlocking between the locking mechanism and the limiting member can be achieved by driving the limiting member to move axially inward through the unlocking member or by the axial outward movement of the gear when the locking mechanism is unlocked, so as to release the limitation on the third connecting member. At this time, the third connecting member can rotate freely; its structural design is novel. When the folding joint is unfolded and used, the limitation and locking of the third connecting member can be released only through the unlocking member, so as to adjust whether the third connecting member is opened or not and the opening angle; when the folding joint is folded, the limitation and locking of the third connecting member can be released synchronously when the locking mechanism is unlocked, and the unlocking of the entire folding joint can be achieved without operating the unlocking member additionally. This design makes the folding operation more convenient and fast, and can achieve single-handed unlocking. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly introduced below. The drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the limited conditions for the implementation of the present utility model. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope that the technical content disclosed by the present utility model can cover.

[0019] Figure 1 Schematic diagram of the three-dimensional structure of the present utility model at the joint of the upper surround frame of the bassinet;

[0020] Figure 2 is Figure 1 Schematic diagram of the side structure;

[0021] Figure 3 is Figure 2 Schematic diagram of the sectional structure of A-A in

[0022] Figure 4 is Figure 3 Schematic diagram of the partially enlarged structure in

[0023] Figure 5 is Figure 1 Schematic diagram of the assembled structure;

[0024] Figure 6 is Figure 5 Schematic diagram of the partially enlarged structure in

[0025] Figure 7 Schematic diagram of the three-dimensional structure of the gear in the present utility model;

[0026] Figure 8 Schematic diagram of the three-dimensional structure of the present utility model at the joint of the push rod of the baby stroller.

[0027] Wherein: 1 First connecting member;

[0028] 2 Second connecting member;

[0029] 3 Third connecting member; 301 Third tooth groove; 302 Button groove;

[0030] 4 Locking mechanism; 401 First tooth groove; 402 Second tooth groove; 403 Gear; 4031 Fourth tooth groove; 4032 Moving groove; 404 Linking block; 405 Unlocking block; 406 Unlocking operation component;

[0031] 5 Limiting member; 501 Outer limiting portion; 502 Inner limiting portion;

[0032] 6 Unlocking member; 601 Extended barb;

[0033] 7 First spring;

[0034] 8 Spacer;

[0035] 9 Second spring. Detailed implementation manners

[0036] To make the objectives, technical solutions and advantages of this application clearer, the following will clearly and completely describe the technical solutions of the embodiments of this application with reference to the accompanying drawings of the embodiments of this application. Apparently, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of this application without creative efforts shall fall within the scope of protection of this application. It can be understood that, without conflict, some technical means described in the various embodiments herein may be replaced or combined with each other.

[0037] In the descriptions of the specification and claims of this application, if there are terms such as "first", "second", etc., they are only used to distinguish the described objects and do not have any sequential or technical meanings. Thus, the objects defined with "first", "second", etc. may explicitly or implicitly include one or more of such objects. Also, words such as "one" or "a" do not indicate a quantity limitation, but rather indicate the existence of at least one, and "multiple" means not less than two.

[0038] In the descriptions of the specification and claims of this application, if there are terms such as "connected", "installed", "fixed", "accommodated", etc., unless otherwise specified, they should all be understood in a broad sense. For example, "connected" can be a separable connection or an integral connection; it can be directly connected or indirectly connected through an intermediate medium; it can be an inseparable connection or a detachable connection. Also, for example, "accommodated" does not necessarily mean that the whole is completely accommodated, and this concept also includes a situation where a part protrudes outside and is partially accommodated. For those skilled in the art, the specific meanings of the foregoing terms in this application can be understood according to specific circumstances.

[0039] In the descriptions of the specification and claims of this application, if there are terms such as "upper", "lower", "horizontal", etc. indicating an orientation or positional relationship, it is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the purpose of clearly and simply describing this application, rather than indicating or implying that the element referred to must have a specific direction, be constructed and operated in a specific orientation. These directional terms are relative concepts used for relative description and clarification, and can change accordingly with the change of the orientation in which the components are placed in the drawings. For example, if the device in the figure is flipped, the element described as "below" other elements will be positioned "above" other elements.

[0040] In the descriptions of the specification and claims of this application, if there is the term "if", depending on the context, it can usually be interchanged with "when", "while", "in response to determining", or "in response to detecting".

[0041] In the description of the specification and claims of the present application, regarding the "direction" of movement, including movement with a direction component, the term "in the direction" is not necessarily understood as movement only in that one direction. For those skilled in the art, the specific meaning of the foregoing term in the present application can be understood according to specific circumstances.

[0042] As Figures 1 to 8 shown, a folding joint structure includes a first connecting member 1, a second connecting member 2, and a third connecting member 3 that are rotatably connected. A locking mechanism 4 is provided between the first connecting member 1 and the second connecting member 2 to lock them when they are in the unfolded position. A limiting member 5 that can axially move relative to and cannot rotate relative to the rotational connection of the third connecting member 3 is installed at the rotational connection of the third connecting member 3. The limiting member 5 is movably connected to the locking mechanism 4, and the locking or unlocking of the locking mechanism 4 on the limiting member 5 can be achieved by changing the axial distance between the two. An unlocking member 6 that can be pressed and can push the limiting member 5 to axially move is provided on the third connecting member 3.

[0043] In this embodiment, the locking mechanism 4 includes a gear 403 that can be simultaneously locked into a first tooth groove 401 of the first connecting member 1 and a second tooth groove 402 of the second connecting member 2, and an unlocking mechanism that can drive the gear 403 to axially move. The unlocking mechanism drives the gear 403 to axially move outwards so that the gear 403 exits the first tooth groove 401 and completely enters the second tooth groove 402 to release the locking of the first connecting member 1 and the second connecting member 2.

[0044] Among them, the unlocking mechanism includes a linkage block 404 that is coaxially arranged with the gear 403 and can axially move, and an unlocking block 405 that is arranged in the first tooth groove 401 and can radially slide relative to it. The unlocking block 405 is in inclined surface cooperation with the linkage block 404. An unlocking operation assembly 406 is provided on the first connecting member 1. The unlocking operation assembly 406 is connected to the unlocking block 405 through a traction cable and can drive the unlocking block 405 to slide. When the unlocking block 405 slides along the unlocking direction, it drives the linkage block 404 to axially move through inclined surface cooperation. The linkage block 404 pushes the gear 403 and makes the gear 403 exit the first tooth groove 401 and completely enter the second tooth groove 402 to release the locking of the first connecting member 1 and the second connecting member 2.

[0045] In this embodiment, the unlocking operation assembly 406 is preferably a rotary unlocking handle assembly or a pressing unlocking assembly. Since the unlocking operation assembly 406 is diverse in the technical field, of course, it can also be other unlocking assemblies that can drive the unlocking block to slide, so no specific elaboration and limitation are made here.

[0046] In this embodiment, the rotational joints of the first connecting member 1, the second connecting member 2, and the third connecting member 3 are coaxially rotationally connected in sequence from the inside out, and the gear 403 and the limiting member 5 are coaxially arranged with the above three; a first spring 7, a spacer 8, and a second spring 9 are coaxially arranged in sequence between the gear 403 and the limiting member 5; the outer end of the limiting member 5 is an outer limiting portion 501 with a plurality of convex teeth evenly spaced on the outer circumference, and the inner end of the limiting member 5 is an inner limiting portion 502 with a plurality of convex teeth spaced on the outer circumference. The lower end of the third connecting member 1 has a third tooth groove 301 for the outer limiting portion 501 to be inserted and move axially. One side of the gear 403 close to the limiting member 5 has a fourth tooth groove 4031 corresponding to the inner limiting portion 502, and the middle of the gear 403 has an activity groove 4032 communicating with the fourth tooth groove 4031 and allowing the inner limiting portion 502 to rotate; the lower end of the third connecting member 3 has an unlocking member 6 that can be pressed and can push the limiting member 5 to move axially inward.

[0047] Among them, the limiting member 5 includes a cylindrical portion. The inner limiting portion 502 is formed at the inner end of the cylindrical portion. The outer limiting portion 501 is formed at the outer end of the cylindrical portion, and its outer diameter is larger than the outer diameter of the inner limiting portion, and its inner diameter is smaller than the inner diameter of the cylindrical portion.

[0048] Among them, the first spring 7, the spacer 8, and the second spring 9 are arranged inside the cylindrical portion of the limiting member 5. One end of the first spring 7 abuts against the gear 403, and the other end abuts against the inner side surface of the spacer 8. One end of the second spring 9 abuts against the outer side surface of the spacer 8, and the other end abuts against the inner side surface of the outer limiting portion 501.

[0049] In this embodiment, the unlocking member 6 is preferably an unlocking button. The rotational joint of the third connecting member 3 has a button groove 302 for installing the unlocking member 6. The outer end of the unlocking member 6 is exposed to form a pressing portion, and the inner side of the unlocking member 6 has an extending barb 601 that axially extends and extends into the third tooth groove; when the unlocking member 6 is pressed, its extending barb 601 squeezes inward and pushes the limiting member 5 to move axially inward.

[0050] The working principle of the present utility model is:

[0051] When the folding joint is in the deployed and in-use state, the first connecting member 1 and the second connecting member 2 are locked in the deployed state by the locking mechanism 4. The outer end of the limiting member 5 is limited in cooperation with the third tooth groove 301 of the third connecting member 3 through the outer limiting portion 501, and the inner end of the limiting member 5 is limited in cooperation with the fourth tooth groove 4031 of the gear 403 through the inner limiting portion 502. At this time, the limiting member 5 and the locking mechanism 4 are limited and locked, and the third connecting member 3 is held in the deployed position and cannot rotate relative to the first connecting member 1 and the second connecting member 2 that are deployed. When the third connecting member 3 needs to rotate, the unlocking member 6 can be driven to axially move the limiting member 5 inward in the third tooth groove 301 of the third connecting member 3, so that the inner limiting portion 502 of the limiting member 5 enters the movable groove 4032 of the gear 403 and can rotate in the movable groove 4032 of the gear 403, realizing the unlocking between the locking mechanism 4 and the limiting member 5, and releasing the limitation on the third connecting member 3. At this time, the third connecting member 3 can rotate freely to adjust whether the third connecting member 3 is opened or not and the opening angle of the third connecting member 3.

[0052] When the folding joint needs to be folded, an unlocking operation is performed on the unlocking operation assembly 406. The unlocking operation assembly 406 drives the unlocking block 405 to slide radially through the towing cable. When the unlocking block 405 slides along the unlocking direction, it drives the linkage block 404 to move axially through the inclined surface cooperation. The linkage block 404 pushes the gear 403 and makes the gear 403 withdraw from the first tooth groove 401 and completely enter the second tooth groove 402 to release the locking of the first connecting member 1 and the second connecting member 2; at the same time, the outwardly moving gear 403 makes its movable groove 4032 move to a position relative to the inner limiting portion 502 of the limiting member 5. At this time, the outer limiting portion 501 of the limiting member 5 still cooperates with the third tooth groove 301 of the third connecting member 3 for limiting, but its inner limiting portion 502 can rotate relative to the movable groove 4032 of the gear 403, so the limitation on the third connecting member 3 is released. At this time, the third connecting member 3 can rotate freely.

[0053] As Figures 1 to 7 shown, the folding joint structure can be used on a children's sleeping basket that can be folded forward and backward. The first connecting member is the front surrounding rod of the upper surrounding frame, the second connecting member is the rear surrounding rod of the upper surrounding frame, and the third connecting member is the awning rod. As Figure 8 shown, the folding joint structure can be used at the push rod joint of a baby stroller. The first connecting member is the upper push rod, the second connecting member is the lower push rod, and the third connecting member is the awning rod.

[0054] The structure design of the utility model is novel. When the folding joint is unfolded for use, the limit locking of the third connecting member 3 (awning rod) can be released solely through the unlocking member 6, so as to adjust whether the third connecting member 3 (awning rod) is opened or not and the opening angle of the third connecting member 3 (awning rod); when the folding joint is folded, the limit locking of the third connecting member 3 (awning rod) can be released synchronously when the locking mechanism 4 is unlocked, and the unlocking of the entire folding joint can be achieved without pressing the unlocking member 6 additionally. This design makes the folding operation simpler and faster, and can be unlocked with one hand.

[0055] In addition, the folding joint structure can also be used at the front armrest joint of a baby stroller or at different folding parts of other baby appliances. Since the application of this folding joint can be conceived by those skilled in the art, no specific elaboration or limitation will be made here.

[0056] As a preferred embodiment of the present invention, in the description of this specification, the description referring to terms such as "preferred" and "optional" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0057] The above embodiments are only used to illustrate the detailed solutions of the present invention. The present invention is not limited to the above detailed solutions, that is, it does not mean that the present invention must rely on the above detailed solutions to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the products of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A folding joint structure, comprising a first connecting member, a second connecting member and a third connecting member which are rotatably connected, characterized in that: A locking mechanism is provided between the first connecting member and the second connecting member, which can lock the first connecting member when the first connecting member is in the deployed position; a limiting member is installed at the rotation connection of the third connecting member, which can move axially relative to the third connecting member but cannot rotate relative to the third connecting member; the limiting member is movably connected to the locking mechanism, and the locking mechanism can lock the limiting member by changing the axial distance between the two; and the third connecting member has an unlocking member that can be pressed and can push the limiting member to move axially; When the folding joint is in an unfolded state, the first connecting member and the second connecting member are unfolded and locked by a locking mechanism, and the limiting member and the locking mechanism are locked in a limited position. At this time, the third connecting member is kept in the unfolded position and cannot rotate relative to the unfolded first connecting member and the second connecting member. When the third connecting member needs to rotate, the locking mechanism and the limiting member can be unlocked by driving the limiting member to axially displace through the unlocking member or by the axial displacement of the limiting member relative to the locking mechanism when the locking mechanism is unlocked. At this time, the third connecting member can rotate freely.

2. A folding joint structure according to claim 1, characterized in that: The locking mechanism includes a gear that can be locked into the first tooth groove of the first connecting member and the second tooth groove of the second connecting member at the same time, and an unlocking mechanism that can drive the gear to move axially. The unlocking mechanism releases the lock of the first connecting member and the second connecting member by driving the gear to move axially so that the gear exits the first tooth groove and completely enters the second tooth groove.

3. A folding joint structure according to claim 2, characterized in that: The rotational connection parts of the first connecting member, the second connecting member and the third connecting member are coaxially connected from the inside to the outside in sequence; the first spring, the spacer and the second spring are coaxially arranged in sequence between the gear and the limit member; the outer end of the limit member is an outer limit member with a plurality of convex teeth evenly spaced at an outer circumference, the inner end of the limit member is an inner limit member with a plurality of convex teeth spaced at an outer circumference, the lower end of the third connecting member has a third tooth groove for the outer limit member to be inserted into and axially move, the side of the gear close to the limit member has a fourth tooth groove corresponding to the inner limit member, and the middle part of the gear has a movable groove that is communicated with the fourth tooth groove and can allow the inner limit member to rotate; When the third connecting member is in a locked limited state, the outer end of the limiting member is limited by the outer limiting portion and the third tooth groove of the third connecting member, and the inner end of the limiting member is limited by the inner limiting portion and the fourth tooth groove of the gear; when the third connecting member needs to be rotated, the limiting member can be driven to move axially inward by the unlocking member or the gear can be moved axially outward when the locking mechanism is unlocked, thereby releasing the limit on the third connecting member, and the third connecting member can be rotated at will.

4. A folding joint structure according to claim 2, characterized in that: The unlocking mechanism includes a linkage block that is coaxially arranged with the gear and can move axially, and an unlocking block that is arranged in the first tooth groove and can slide radially relative to the gear. The unlocking block cooperates with the inclined surface of the linkage block. An unlocking operation component is provided on the first connecting member. The unlocking operation component is connected to the unlocking block through a traction rope and can drive the unlocking block to slide. When the unlocking block slides in the unlocking direction, it drives the linkage block to move axially through the inclined surface. The linkage block pushes the gear and causes the gear to exit the first tooth groove and completely enter the second tooth groove to release the lock of the first connecting member and the second connecting member.

5. A folding joint structure according to claim 3, characterized in that: The limiting member includes a cylindrical portion, the inner limiting portion is formed at the inner end of the cylindrical portion, the outer limiting portion is formed at the outer end of the cylindrical portion and has an outer diameter larger than the outer diameter of the inner limiting portion and an inner diameter smaller than the inner diameter of the cylindrical portion.

6. A folding joint structure according to claim 5, characterized in that: The first spring, spacer and second spring are arranged in the cylindrical part of the limit member, one end of the first spring abuts on the gear, and the other end abuts on the inner side surface of the spacer, one end of the second spring abuts on the outer side surface of the spacer, and the other end abuts on the inner side surface of the outer limit portion.

7. The folding joint structure according to claim 3, characterized in that: The unlocking member is an unlocking button, and the rotating connection of the third connecting member has a button groove for installing the unlocking member. The outer end of the unlocking member is exposed to form a pressing portion, and the inner side of the unlocking member has an extended barb that extends axially and extends into the third tooth groove; when the unlocking member is pressed, the extended barb is squeezed inward and pushes the limit member to move axially inward.