Stroller and joint structures thereof

Abstract

A stroller (1000) and a joint structure (200) thereof. The joint structure comprises: a first connecting base (210), a second connecting base (220) and a third connecting base (230), which are successively and pivotally connected to each other around the axial direction, the first connecting base being provided with a first limiting column (211), the second connecting base being provided with a second limiting column (221), the third connecting base being provided with a third limiting column (231), and the first limiting column, the third limiting column and the second limiting column being successively arranged in the circumferential direction; and a first locking member (240), which is movably provided between the first connecting base and the second connecting base in the axial direction and has a first locking position and a first unlocking position. When the first locking member is located at the first locking position, the first connecting base, the second connecting base and the third connecting base are relatively fixed, and the third limiting column at least abuts against one of the first limiting column and the second limiting column; and when the first locking member is located at the first unlocking position, the first connecting base and the third connecting base all can pivot relative to the second connecting base. When the stroller is in a deployed state, the joint structure can keep the connecting bases stably fixed.

Description

Cart and its joint structure

[0001] Related applications

[0002] This application claims priority to Chinese patent applications filed on April 2, 2024, with application number 2024104017005, entitled “Cart and its joint structure”; filed on September 2, 2024, with application number 2024112258198, entitled “Cart and its joint structure”; and filed on March 28, 2025, with application number 2025103899686, entitled “Cart and its joint structure”, the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the technical field of wheeled mobile devices, and in particular to a cart and a joint structure thereof. Background Art

[0004] For families with infants and young children, using a stroller as an auxiliary care tool when out and about has become very common and convenient. Strollers primarily consist of a frame and seat, and most are foldable. When the stroller is not in use, the frame and seat can be folded to reduce its size for easy storage or portability. However, despite the convenience of this folding design, traditional folding joints are often complex, resulting in a larger size. This not only takes up a lot of space but also makes the stroller appear bulky and unsightly. Summary of the Invention

[0005] Based on this, it is necessary to provide a cart and a joint structure thereof to address the above problems.

[0006] 14. The joint structure of claim 13, wherein the first connecting seat, the second connecting seat, and the third connecting seat are pivotally connected to each other about an axial direction, the second connecting seat is located between the first connecting seat and the third connecting seat along the axial direction, and the first connecting seat is provided with a first limiting post, the second connecting seat is provided with a second limiting post, and the third connecting seat is provided with a third limiting post, and the first limiting post, the third limiting post, and the second limiting post are arranged in sequence along the circumferential direction; a first locking member is movably provided between the first connecting seat and the second connecting seat, and has a first locking position and a first releasing position, and is located on one radial side of the first limiting post, the second limiting post, and the third limiting post; when the first locking member is in the first locking position, the first connecting seat, the second connecting seat, and the third connecting seat are relatively fixed, and the third limiting post abuts against at least one of the first limiting post and the second limiting post; when the first locking member is in the first releasing position, the first connecting seat and the third connecting seat can both pivot relative to the second connecting seat.

[0007] In one embodiment, the first limiting column protrudes toward the second connecting seat, the second limiting column protrudes toward the first connecting seat, the third limiting column protrudes toward the first connecting seat and passes through the second connecting seat, and the second connecting seat is provided with a movable groove for the third limiting column to move along the circumferential direction, and the first limiting column and the third limiting column can move along the circumferential direction within the second connecting seat.

[0008] In one embodiment, the first locking member is located radially outside the first limiting column, the second limiting column, and the third limiting column.

[0009] In one embodiment, the joint structure further includes a driving member, which is movably arranged between the first connecting seat and the second connecting seat and has an initial position and an unlocking position. When the driving member moves from the initial position to the unlocking position, the driving member drives the first locking member to move from the first locking position to the first releasing position. The driving member and the first locking member are arranged adjacent to each other along the axial direction, and the driving member and the first locking member are both located radially outside the first limiting column, the second limiting column and the third limiting column.

[0010] In one embodiment, the driving member is located between the first connecting seat and the first locking member and is disposed adjacent to the first locking member. The driving member is used to drive the first locking member to move to the second connecting seat and to the first unlocking position.

[0011] In one embodiment, the first connecting seat, the second connecting seat and the third connecting seat are pivotally connected to each other at a first pivot, and the first pivot limits the first connecting seat, the second connecting seat and the third connecting seat from being separated in the axial direction.

[0012] In one embodiment, when the first locking member is in the first locking position, the first locking member is engaged with the first connecting seat and the second connecting seat at the same time; when the first locking member is in the first releasing position, the first locking member is engaged with the second connecting seat and disengaged from the first connecting seat, so that the first connecting seat can pivot relative to the second connecting seat.

[0013] In one embodiment, a first elastic member is provided between the first locking member and the second connecting seat, and the first elastic member provides an elastic restoring force for the first locking member to keep the first locking member in the first locking position.

[0014] In one embodiment, the joint structure further includes a second locking member, which is movably arranged in the joint structure and is provided with at least one locking portion, the locking portion being spaced apart from the axial direction, the second locking member having a second locking position and a second release position, when the first locking member is in the first locking position, the second locking member is in the second locking position, the at least one locking portion passes through the third connecting seat and the second connecting seat, when the first locking member is in the first release position, the second locking member is in the second release position, the at least one locking portion only passes through the third connecting seat or the second connecting seat.

[0015] In one embodiment, when the first locking member moves from the first locking position to the first unlocking position, the first locking member drives the second locking member to move from the second locking position to the second unlocking position.

[0016] In one embodiment, when the first locking member moves to the second connecting seat, the first locking member drives the at least one locking portion to move away from the second connecting seat, so that the at least one locking portion only passes through the third connecting seat to the second unlocking position.

[0017] A cart comprising: a hand frame, a front wheel frame, a rear wheel frame and the above-mentioned joint structure, wherein the hand frame is connected to the first connecting seat, the front wheel frame is connected to the second connecting seat, and the rear wheel frame is connected to the third connecting seat, the hand frame, the front wheel frame and the rear wheel frame are pivotally connected to each other through the joint structure, so that the cart can be switched between an extended state and a folded state, and the rear wheel frame is circumferentially located between the front wheel frame and the hand frame; when the cart is in the extended state, the first locking member is in the first locking position, and the hand frame, the front wheel frame and the rear wheel frame are circumferentially spaced apart; when the cart is in the folded state, the hand frame is circumferentially close to the rear wheel frame, and the rear wheel frame is circumferentially close to the front wheel frame.

[0018] In one embodiment, when the stroller is in the folded state, the first locking member is in the first unlocking position.

[0019] In one embodiment, when the cart is in the folded state, the first limiting post, the third limiting post and the second limiting post are arranged at intervals along the circumferential direction.

[0020] In one embodiment, when the cart is in the folded state, the third limiting post abuts against a groove wall of the movable groove on a side away from the second limiting post along the circumferential direction.

[0021] In one embodiment, the first connecting seat is provided with a first engaging member, and the second connecting seat is provided with a second engaging member. The first engaging member and the second engaging member are both located between the first limiting column and the second limiting column along the circumferential direction, and are located on the side of the first limiting column and the second limiting column away from the third limiting column along the circumferential direction; when the cart is in the folded state, the first engaging member abuts against the second engaging member on the side of the second engaging member close to the second limiting column.

[0022] In one embodiment, when the cart is in the extended state, the first engaging member is located on a side of the second engaging member close to the first limiting column and is spaced apart from the second engaging member.

[0023] In one embodiment, the first engaging member includes an elastic arm and a convex bump, the elastic arm has an elastic force for elastic deformation along the radial direction, and the convex bump is located radially inside the elastic arm; when the cart is in the folded state, the elastic arm is at least partially located radially outside the second engaging member, and the convex bump abuts against the second engaging member on a side of the second engaging member close to the second limiting column.

[0024] In one embodiment, at least one of the first engaging member and the second engaging member is provided with a guiding slope, and when the first connecting seat rotates circumferentially relative to the second connecting seat, the guiding slope is used to guide the first engaging member to move from the side of the second engaging member close to the first limiting column to the side of the second engaging member close to the second limiting column.

[0025] In one embodiment, a first blocking portion is provided on the outer side of the second connecting seat, and a second blocking portion is provided on the outer side of the third connecting seat. When the first locking member is located at the first unlocking position and the cart is not in the folded state, the first blocking portion and the second blocking portion abut against each other along the circumferential direction.

[0026] In one embodiment, the first blocking portion is arranged on the outer periphery of the second connecting seat, the first blocking portion extends toward the third connecting seat and protrudes relative to the outer periphery of the second connecting seat; the second blocking portion is arranged on the outer periphery of the third connecting seat, the second blocking portion extends toward the second connecting seat and protrudes relative to the outer periphery of the third connecting seat.

[0027] In one embodiment, the first connecting seat is provided with a first pushing portion, which is formed by protruding toward the second connecting seat, and the first pushing portion is spaced apart from the first limiting column along the circumferential direction. When the cart is in the folded state, the first pushing portion is located between the first limiting column and the third limiting column in the circumferential direction, and the third limiting column is located between the first pushing portion and the second limiting column in the circumferential direction. When the cart switches from the folded state to the extended state, the first pushing portion pushes the third limiting column in the direction close to the second limiting column.

[0028] In one embodiment, when the cart is in the folded state, the first pushing portion is circumferentially located between the first limiting column and the third limiting column; when the cart is in the extended state, the third limiting column is circumferentially located between the first limiting column and the first pushing portion; the first pushing portion can be elastically deformed in the radial direction.

[0029] In one embodiment, the second limiting column is located on one side of a trajectory of the first pushing portion moving along the circumferential direction in a direction parallel to the axial direction.

[0030] In one embodiment, the plane where the end surface of the first push portion facing the second connecting seat is located and the plane where the end surface of the second limiting column facing the first connecting seat is located are spaced apart from each other or are exactly flush with each other in a direction parallel to the axial direction.

[0031] In one embodiment, the first pushing portion is configured as an elastic arm, and an extending direction of the elastic arm intersects with the circumferential direction.

[0032] In one embodiment, the third limiting column is provided with an abutting surface on one side close to the first limiting column, and the abutting surface is located on the trajectory of the first pushing portion moving along the circumferential direction. When the first pushing portion abuts against the abutting surface, the angle between the extension direction of the abutting surface and the extension direction of the first pushing portion is between 65° and 75°.

[0033] In one embodiment, the first connecting seat is further provided with a fourth limiting column, which protrudes toward the second connecting seat and is spaced apart from the first limiting column along the circumferential direction. When the cart is in the extended state, the third limiting column is circumferentially located between the first limiting column and the fourth limiting column. When the cart switches from the extended state to the folded state, the fourth limiting column pushes the third limiting column to move the third limiting column away from the second limiting column.

[0034] In one embodiment, when the cart is in the extended state, the fourth limit post is arranged farther away from the third limit post than the second limit post, and the fourth limit post is used to pass over the second limit post in the circumferential direction to push the third limit post to move away from the second limit post.

[0035] In one embodiment, the second limiting post is located on one side of a trajectory of the fourth limiting post moving along the circumferential direction in a direction parallel to the axial direction.

[0036] In one embodiment, the plane where the end surface of the fourth limiting column facing the second connecting seat is located and the plane where the end surface of the second limiting column facing the first connecting seat is located are spaced apart from each other in a direction parallel to the axial direction or are exactly flush with each other.

[0037] In one embodiment, the first pushing portion is located between the first limiting column and the fourth limiting column in the circumferential direction.

[0038] In one embodiment, a circumferential distance between the first pushing portion and the fourth limiting column is greater than or equal to a maximum circumferential width of the third limiting column.

[0039] In one embodiment, when the cart is in the extended state, the third limiting post is circumferentially located between the first limiting post and the first pushing portion, and the fourth limiting post is circumferentially located further away from the third limiting post than the first pushing portion.

[0040] In one embodiment, a crimping surface is provided on the side of the third limiting column close to the second limiting column, and the crimping surface is located on the trajectory of the first pushing portion moving along the circumferential direction. When the first pushing portion contacts the crimping surface, the angle between the extension direction of the crimping surface and the extension direction of the first pushing portion is between 0° and 25°.

[0041] In one embodiment, the cart also includes a seat and a fourth connecting seat, the fourth connecting seat and the third connecting seat are pivotally connected to each other around the axis, the second connecting seat and the third connecting seat are both located between the first connecting seat and the fourth connecting seat, and the seat is connected to the fourth connecting seat.

[0042] In one embodiment, the handle frame includes a first handle frame, a second handle frame and a folding joint, and the second handle frame is pivotally connected to the first handle frame through the folding joint so that the first handle frame can be expanded or folded relative to the second handle frame. The cart also includes a third traction member, which is connected to the first handle frame and the seat. When the first handle frame is expanded relative to the second handle frame, the first handle frame drives the seat to rotate circumferentially away from the rear wheel frame through the third traction member.

[0043] In one embodiment, the fourth connecting seat is provided with a second pushing portion, and the second connecting seat is provided with a third pushing portion. The second pushing portion and the third pushing portion are circumferentially arranged opposite to each other. When the first handle frame drives the seat to rotate circumferentially away from the rear wheel frame through the third traction member, the second pushing portion abuts against the third pushing portion to drive the front wheel frame to rotate circumferentially away from the rear wheel frame.

[0044] In one embodiment, the third connecting seat is provided with a limiting groove, at least part of the second pushing portion and at least part of the third pushing portion protrude into the limiting groove, and the second pushing portion and the third pushing portion move circumferentially in the limiting groove.

[0045] In one embodiment, one end of the limiting groove in the circumferential direction is used to abut against the second pushing portion, and the other end of the limiting groove in the circumferential direction is used to abut against the third pushing portion.

[0046] In one embodiment, the process of switching the cart from the folded state to the extended state includes a first stage and a second stage; in the first stage, the handle frame rotates circumferentially in a direction away from the front wheel frame, and the handle frame drives the rear wheel frame to rotate circumferentially in a direction away from the front wheel frame; in the second stage, the first handle frame is unfolded relative to the second handle frame, the first handle frame drives the seat to rotate along the circumferential direction away from the rear wheel frame through the third traction member, and the seat drives the front wheel frame to rotate along the circumferential direction away from the rear wheel frame.

[0047] and a second locking member being movably provided in the joint structure and provided with at least one locking portion, the locking portion being spaced apart from the axial direction, the second locking member having a second locking position and a second releasing position, when the second locking member is in the first locking position and the second releasing position. When the fixing member is in the second locking position, the at least one locking portion passes through the third connecting seat and the second connecting seat, so that the second connecting seat and the third connecting seat are relatively fixed. When the second locking member is in the second unlocking position, the at least one locking portion only passes through the third connecting seat or the second connecting seat, so that the second connecting seat can pivot relative to the third connecting seat; and a driving member, movably arranged between the first connecting seat and the second connecting seat, and having an initial position and an unlocking position, the driving member is arranged adjacent to the first locking member and / or the second locking member, and when the driving member moves from the initial position to the unlocking position, the driving member drives the first locking member to move from the first locking position to the first unlocking position, and drives the second locking member to move from the second locking position to the second unlocking position.

[0048] In one embodiment, when the driving member moves from the initial position to the unlocking position, the driving member directly drives the first locking member to move from the first locking position to the first unlocking position; when the first locking member moves from the first locking position to the first unlocking position, the first locking member drives the second locking member to move from the second locking position to the second unlocking position.

[0049] In one embodiment, the driving member is axially located between the first connecting seat and the first locking member and is arranged adjacent to the first locking member. The driving member is used to drive the first locking member to move to the second connecting seat to the first release position. When the first locking member moves to the second connecting seat, the first locking member drives the at least one locking portion to move away from the second connecting seat, so that the at least one locking portion only passes through the third connecting seat to move the second locking member to the second release position.

[0050] In one embodiment, the joint structure also includes: a fourth connecting seat, which is axially pivotally connected to the third connecting seat, and the second connecting seat and the third connecting seat are both located between the first connecting seat and the fourth connecting seat; and a third locking member, which is movably arranged between the third connecting seat and the fourth connecting seat and has a third locking position and a third release position. When the third locking member is in the third locking position, the third connecting seat and the fourth connecting seat are relatively fixed. When the third locking member is in the third release position, the third connecting seat can pivot relative to the fourth connecting seat; when the driving member moves from the initial position to the unlocking position, the driving member drives the third locking member to move from the third locking position to the third release position.

[0051] In one embodiment, when the second locking member moves from the second locking position to the second unlocking position, the second locking member drives the third locking member to move from the third locking position to the third unlocking position.

[0052] In one embodiment, when the at least one locking portion moves to be disengaged from the second connecting seat, the at least one locking portion drives the third locking member to move to the fourth connecting seat to the third unlocking position.

[0053] In one embodiment, when the third locking member is in the third locking position, the third locking member is engaged with the third connecting seat and the fourth connecting seat at the same time; when the third locking member is in the third releasing position, the third locking member is engaged with the fourth connecting seat and disengaged from the third connecting seat, so that the fourth connecting seat can pivot relative to the third connecting seat.

[0054] In one embodiment, a second elastic member is provided between the third locking member and the fourth connecting seat, and the second elastic member provides an elastic restoring force for the third locking member to keep the third locking member in the third locking position.

[0055] In one embodiment, the second locking member is provided with a main body portion, and the at least one locking portion is formed by protruding from the main body portion in a direction parallel to the axial direction. The main body portion is located between the third connecting seat and the third locking member, and is arranged adjacent to the third locking member.

[0056] In one embodiment, the second locking member is provided with a plurality of locking portions, and the plurality of locking portions are arranged at intervals along the circumferential direction.

[0057] 14. The stroller as claimed in claim 13, wherein the first and second connecting members are connected to each other via the joint structure so that the stroller can be switched between an extended state and a folded state, and the rear wheel frame is located between the front wheel frame and the stroller frame along the circumferential direction. When the stroller is in the extended state, the driving member is in the initial position, the first locking member is in the first locking position, the second locking member is in the second locking position, and the stroller frame, the front wheel frame and the rear wheel frame are spaced apart along the circumferential direction. When the stroller is in the folded state, the stroller frame is circumferentially close to the rear wheel frame, and the rear wheel frame is circumferentially close to the front wheel frame.

[0058] In one embodiment, when the stroller is in the folded state, the driving member is in the unlocked position, the first locking member is in the first unlocked position, and the second locking member is in the second unlocked position.

[0059] In one embodiment, a first blocking portion is provided on the outer side of the second connecting seat, and a second blocking portion is provided on the outer side of the third connecting seat. When the driving member is in the unlocking position, the first locking member is in the first releasing position, the second locking member is in the second releasing position, and the cart is not in the folded state, the first blocking portion and the second blocking portion abut each other along the circumferential direction.

[0060] In one embodiment, the handle frame includes a first push handle frame, a second push handle frame and a folding joint, the second push handle frame is pivotally connected to the first push handle frame through the folding joint, so that the first push handle frame can be expanded or folded relative to the second push handle frame, and the folding joint includes: a fifth connecting seat connected to the first push handle frame; a sixth connecting seat connected to the second push handle frame, the sixth connecting seat and the fifth connecting seat are pivotally connected to each other, so that the first push handle frame can be expanded or folded relative to the second push handle frame, one of the fifth connecting seat and the sixth connecting seat is provided with a limiting recess, and the other is provided with a fifth locking member, the fifth locking member is movably arranged on the other of the fifth connecting seat and the sixth connecting seat and has a first position and a second position, when the fifth locking member is in the first position, the fifth locking member extends into the limiting recess so that the first push handle frame and the second push handle frame remain relatively folded, and when the fifth locking member is in the second position, the fifth locking member retracts from the limiting recess to allow the first push handle frame to pivot relative to the second push handle frame.

[0061] In one embodiment, at least one of the end of the fifth locking member facing the limiting recess and the limiting recess is provided with a sliding inclined surface suitable for releasing the limit.

[0062] In one embodiment, the folding joint also includes a limit cover and a third elastic member, the fifth connecting seat is provided with a movable hole, the fifth locking member is movably inserted into the movable hole, the limit cover is provided on the side of the fifth connecting seat facing away from the sixth connecting seat, the third elastic member abuts between the limit cover and the fifth locking member to keep the fifth locking member in the first position; the sixth connecting seat is provided with the limit recess.

[0063] In one embodiment, the handle frame includes a first handle frame and a second handle frame, the second handle frame is pivotally connected to the first handle frame so that the first handle frame can be expanded or folded relative to the second handle frame, the second handle frame is connected to the first connecting seat, and the driving member is connected to the first handle frame through a first traction member. When the first handle frame pivots relative to the second handle frame, the first handle frame drives the first traction member to move to drive the driving member to rotate relative to the first connecting seat and move along the axial direction, so that the driving member moves from the initial position to the unlocked position.

[0064] In one embodiment, the driving member is provided with an abutting portion, which protrudes in a direction parallel to the axial direction and extends obliquely in the circumferential direction; the first connecting seat is provided with a pushing portion, which protrudes in a direction parallel to the axial direction and extends obliquely in the circumferential direction; the abutting portion and the pushing portion abut against each other in a direction parallel to the axial direction.

[0065] In one embodiment, the handle frame includes a first push handle frame, a second push handle frame and a folding joint, and the second push handle frame is pivotally connected to the first push handle frame through the folding joint so that the first push handle frame can be expanded or folded relative to the second push handle frame, and the folding joint includes: a fifth connecting seat, connected to the first push handle frame; a sixth connecting seat, connected to the second push handle frame, the sixth connecting seat is provided with a locking slot, the sixth connecting seat and the fifth connecting seat are pivotally connected to each other so that the first push handle frame can be expanded or folded relative to the second push handle frame; a fourth locking member, movably provided on the first push handle frame, when the first push handle frame and the second push handle frame are relatively expanded, the fourth locking member is inserted into the locking slot to limit the first push handle frame from pivoting relative to the second push handle frame.

[0066] In one embodiment, the handlebar frame further includes a release button, which is movably provided on the first handlebar frame and connected to the fourth locking member via a second traction member. When the release button moves relative to the first handlebar frame, the release button drives the fourth locking member to move relative to the first handlebar frame so as to be able to disengage from the lock slot.

[0067] In one embodiment, the handlebar frame further includes a safety push button, which is movably provided on the first handlebar frame and has a third position and a fourth position. When the safety push button is in the third position, the safety push button abuts against the release button to prevent the release button from moving relative to the first handlebar frame. When the safety push button is in the fourth position, the safety push button is spaced apart from the release button to allow the release button to move relative to the first handlebar frame. The moving direction of the safety push button is staggered with the moving direction of the release button.

[0068] A stroller comprising: a rider frame, a front wheel frame, a rear wheel frame, a seat and the above-mentioned joint structure, wherein the rider frame is connected to the first connecting seat, the front wheel frame is connected to the second connecting seat, the rear wheel frame is connected to the third connecting seat, and the seat is connected to the fourth connecting seat, the rider frame, the front wheel frame, the rear wheel frame and the seat are pivotally connected to each other through the joint structure so that the stroller can switch between an extended state and a folded state; when the stroller is in the extended state, the rider frame, the rear wheel frame, the front wheel frame and the seat are sequentially spaced along the circumferential direction, the driving member is in the initial position, the first locking member is in the first locking position, the second locking member is in the second locking position, and the third locking member is in the third locking position; when the stroller is in the folded state, the rider frame and the rear wheel frame are both moved toward the front wheel frame along the circumferential direction, and the seat is moved toward the rear wheel frame.

[0069] In one embodiment, when the cart is in the folded state, the driving member is in the unlocked position, the first locking member is in the first unlocked position, the second locking member is in the second unlocked position, and the third locking member is in the third unlocked position.

[0070] In one embodiment, a third blocking portion is provided on the outer periphery of the third connecting seat, and a fourth blocking portion is provided on the outer periphery of the fourth connecting seat. When the third locking member is in the third locking position, the third blocking portion and the fourth blocking portion abut against each other along the circumferential direction.

[0071] In one embodiment, the third blocking portion extends toward the fourth connecting seat and protrudes relative to the outer periphery of the third connecting seat; the fourth blocking portion extends toward the third connecting seat and protrudes relative to the outer periphery of the fourth connecting seat.

[0072] In one embodiment, the seat includes a seat plate, a folding strap passing through the seat plate, and a retracting mechanism connected to both ends of the folding strap. The two ends of the folding strap respectively pass through the seat plate to extend from the first surface of the seat plate to the second surface, and are connected to the retracting mechanism provided on the second surface. The retracting mechanism automatically tightens the folding strap, and the first surface and the second surface are arranged opposite to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] The drawings that constitute a part of this application are used to provide further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute improper limitations on this application.

[0074] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0075] In addition, the drawings are not drawn to a 1:1 scale, and the relative sizes of the various elements are drawn only for illustrative purposes and are not necessarily drawn to true scale.

[0076] FIG1 is a perspective view of a cart according to an embodiment of the present application;

[0077] FIG2 is a perspective view of the cart from another perspective in one embodiment of the present application;

[0078] FIG3 is a cross-sectional view of a cart according to an embodiment of the present application, wherein the cart is in an extended state;

[0079] FIG4 is an enlarged view of circle A in FIG3 ;

[0080] FIG5 is a partial perspective view of the stroller shown in FIG1 with a handlebar frame;

[0081] FIG6 is an exploded schematic diagram of a portion of the structure of the cart shown in FIG1 with a handlebar frame;

[0082] FIG7 is a partial perspective view of the stroller shown in FIG1 with a rider frame from another perspective;

[0083] FIG8 is a cross-sectional view along line U1-U1 in FIG7;

[0084] FIG9 is a cross-sectional view along line U2-U2 in FIG7;

[0085] FIG10 is an enlarged view of circle B in FIG9 ;

[0086] FIG11 is a cross-sectional view of the driver's frame when the fifth locking member in FIG10 extends into the limiting recess;

[0087] FIG12 is a side view of the cart according to an embodiment of the present application, wherein the first handle frame is folded relative to the second handle frame;

[0088] FIG13 is a cross-sectional view of a stroller according to an embodiment of the present application, wherein the handlebar frame is folded toward the front wheel frame and the rear wheel frame;

[0089] FIG14 is a cross-sectional view of a cart according to an embodiment of the present application, wherein the cart is in a folded state;

[0090] FIG15 is a partial exploded perspective view of the cart according to an embodiment of the present application, showing the joint structure of the first embodiment;

[0091] FIG16 is an enlarged view of circle C in FIG15 ;

[0092] FIG17 is an enlarged view of circle D in FIG15 ;

[0093] FIG18 is a partial exploded perspective view of the cart according to one embodiment of the present application from another perspective, showing the joint structure of the first embodiment;

[0094] FIG19 is a cross-sectional view along line U3-U3 in FIG1 ;

[0095] FIG20 is a cross-sectional view along line U4-U4 in FIG12;

[0096] FIG21 is a perspective view of the first connecting seat in FIG15 from another perspective;

[0097] FIG22 is a perspective view of the second connecting base in FIG15 from another perspective;

[0098] FIG23 is a perspective view of the third connecting base in FIG15 from another perspective;

[0099] FIG24 is a perspective view of a seat in one embodiment of the present application;

[0100] FIG25 is a schematic diagram of a partial structure of the reeling mechanism on the seat shown in FIG24;

[0101] FIG26 is a cross-sectional view along line U5-U5 in FIG24;

[0102] FIG27 is a bottom view of a seat in another embodiment of the present application;

[0103] FIG28 is a cross-sectional view of the seat shown in FIG27;

[0104] FIG29 is an exploded view of the joint structure in the second embodiment of the present application;

[0105] FIG30 is an exploded view of the joint structure in the sixth embodiment of the present application;

[0106] FIG31 is an exploded view of the joint structure in the seventh embodiment of the present application;

[0107] FIG32 is an exploded view of the joint structure in the eighth embodiment of the present application;

[0108] FIG33 is an exploded view of the joint structure in the ninth embodiment of the present application;

[0109] FIG34 is an exploded view of the joint structure in the tenth embodiment of the present application;

[0110] FIG35 is an exploded view of the joint structure in the eleventh embodiment of the present application;

[0111] FIG36 is a perspective view of the first connecting seat of the joint structure in the eleventh embodiment of the present application;

[0112] FIG37 is a partial exploded view of the joint structure in the eleventh embodiment of the present application from another angle, in which only the first connecting seat, the second connecting seat, and the third connecting seat are retained;

[0113] FIG38 is a cross-sectional view of the stroller in the eleventh embodiment of the present application in a folded state;

[0114] FIG39 is a cross-sectional view of the third limiting post in the eleventh embodiment of the present application;

[0115] FIG40 is a perspective cross-sectional view of the stroller in the eleventh embodiment of the present application in an extended state. Specifically, FIG40 shows a cross-sectional view of the joint structure, the handlebar frame, and the front wheel frame;

[0116] FIG41 is a cross-sectional view of the cart in the eleventh embodiment of the present application when it is between the folded state and the extended state. Specifically, FIG41 provides a cross-sectional view of the joint structure. DETAILED DESCRIPTION

[0117] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0118] One embodiment of the present invention provides a stroller 1000, which may include a frame 100 and a fabric cover (not shown) mounted on the frame 100. The frame 100 may include a handlebar frame 110, a front wheel frame 120, a rear wheel frame 130, and a joint structure 200 provided in some embodiments of the present invention. The following description of the stroller 1000 and the frame 100 will also include an explanation of the joint structure 200.

[0119] Figures 1 and 2 illustrate a stroller 1000 according to an embodiment of the present invention. The frame 100 of the stroller 1000 is generally bilaterally symmetrical. The handlebar frame 110, front wheel frame 120, and rear wheel frame 130 of the frame 100 are each connected to two joint structures 200. The two joint structures 200 located on the left and right sides of the stroller 1000 allow the handlebar frame 110, front wheel frame 120, and rear wheel frame 130 connected to the joint structures 200 to rotate relative to each other, thereby enabling the handlebar frame 110, front wheel frame 120, and rear wheel frame 130 to be relatively unfolded and folded. In other words, the stroller 1000 can have an extended state (see Figures 1 and 2) and a folded state (see Figure 14). When the stroller 1000 is in use, it can be in the extended state; when it is to be stored, it can be in the folded state to save space and facilitate storage.

[0120] 1 and 2 , in one embodiment, each joint structure 200 may include a first connection seat 210, a second connection seat 220, and a third connection seat 230. The first connection seat 210, the second connection seat 220, and the third connection seat 230 are pivotally connected to each other about an axial direction (the direction around the axial direction is the circumferential direction, and the direction perpendicular to the axial direction is the radial direction), and at least a portion of the second connection seat 220 is axially located between the first connection seat 210 and the third connection seat 230, so that the stroller 1000 has an extended state and a folded state. The first connection seat 210 is used to connect to the handlebar frame 110, the second connection seat 220 is used to connect to the front wheel frame 120, and the third connection seat 230 is used to connect to the rear wheel frame 130. In this way, the stroller 1000 can switch between the extended state and the folded state. Of course, in other embodiments, the second connecting base 220 can be used to connect to the rear wheel frame 130, and the third connecting base 230 can be used to connect to the front wheel frame 120. In this way, the stroller 1000 can also be switched between the extended state and the folded state. Specifically, when the stroller 1000 is in the extended state, the driver frame 110, the front wheel frame 120, and the rear wheel frame 130 are spaced apart along the circumferential direction, and the rear wheel frame 130 is circumferentially located between the front wheel frame 120 and the driver frame 110. The front wheel frame 120 and the rear wheel frame 130 are arranged at a first angle α1 (see FIG. 3 ), and the driver frame 110 and the front wheel frame 120 are arranged at a second angle α2 (see FIG. 3 ). When the cart 1000 is in the folded state, the rider frame 110 is circumferentially close to the rear wheel frame 130, and the rear wheel frame 130 is circumferentially close to the front wheel frame 120. The front wheel frame 120 and the rear wheel frame 130 are arranged at a third angle α3 (see FIG14 ), and the rider frame 110 and the front wheel frame 120 are arranged at a fourth angle α4 (see FIG14 ). The third angle α3 is smaller than the first angle α1, and the fourth angle α4 is smaller than the second angle α2.

[0121] In order to clearly understand the structure of the cart 1000 shown in the present invention, the specific structures of the front wheel frame 120, the rear wheel frame 130, the rider frame 110 and each joint structure 200 will be further described below.

[0122] 1 and 2 , in one embodiment, the front wheel frame 120 is, for example, U-shaped and includes left and right front rods 121 and a front crossbar 122 connected between the two front rods 121. The front crossbar 122 extends generally along a first direction F1, which corresponds to the left-right direction of the stroller 1000. When a child is riding in the stroller 1000, the front crossbar 122 can also serve as a footrest.

[0123] In one embodiment, the cart 1000 further includes at least one front wheel seat 141 mounted on the bottom of the front wheel frame 120. Specifically, in this embodiment, as shown in Figures 1 and 2, the cart 1000 includes two front wheel seats 141 mounted on the bottom of the front wheel frame 120, with the two front wheel seats 141 spaced apart in the left-right direction (i.e., the first direction F1). More specifically, the two front wheel seats 141 are mounted on the left and right ends of the front crossbar 122, and the two front rods 121 are respectively connected to the front wheel seats 141 on the same side. The cart 1000 further includes at least one front wheel 151 mounted on the front wheel seat 141 to enable mobility. Specifically, in this embodiment, the cart 1000 includes two front wheels 151, each front wheel seat 141 being configured to mount a front wheel 151. The front wheels 151 may be swivel wheels or non-swivel wheels. Of course, in other embodiments, the front wheel frame 120 may also have other implementations. For example, the front wheel frame 120 only includes two front rods 121, and one end of the two front rods 121 is connected to form a V-shaped structure. The cart 1000 can install a front wheel seat 141 at the end where the two front rods 121 are connected, and a front wheel seat 141 is connected to a front wheel 151.

[0124] It should be noted that, unless otherwise expressly specified or limited, directional terms such as "left" and "right" regarding the cart 1000 in various embodiments of the present invention are based on the "left" and "right" directions of the cart 1000 during normal travel. Arrows L and R are used in the figures to schematically indicate the "left" and "right" directions. These directional terms are used solely to clarify the description of the embodiments of the present invention and are not intended to unduly limit the scope of protection of the present invention.

[0125] Continuing with Figures 1 and 2, the rear wheel frame 130 can include two rear rods 131 located on either side and a rear crossbar 132 connected between the two rear rods 131. The two rear rods 131 on either side are respectively connected to the front rod 121 on the same side via corresponding joint structures 200. The rear crossbar 132 extends along the first direction F1. Specifically, there are two rear crossbars 132, and the two rear crossbars 132 are spaced apart along the length direction of the rear rods 131. The cart 1000 also includes at least one rear wheel seat 142 mounted to the bottom of the rear wheel frame 130. Specifically, in this embodiment, the cart 1000 includes two rear wheel seats 142 mounted to the bottom of the rear wheel frame 130, and the two rear wheel seats 142 are spaced apart in the left-right direction (i.e., the first direction F1). More specifically, two rear wheel mounts 142 are mounted on the left and right ends of the rear crossbar 132 at the end of the rear rod 131. The two rear rods 131 are respectively connected to the rear wheel mounts 142 on the same side. The cart 1000 also includes rear wheels 152 mounted to the rear wheel mounts 142 to enable mobility. Specifically, in this embodiment, the cart 1000 includes two rear wheels 152, each rear wheel mount 142 being configured to mount a rear wheel 152. The rear wheels 152 may be, for example, casters or non-casters. In this embodiment, the rear wheels 152 are larger than the front wheels 151 to provide greater stability for the overall structure of the cart 1000. Of course, in other embodiments, the rear wheels 152 may be the same size as or smaller than the front wheels 151.

[0126] Alternatively, in other embodiments, the rear wheel frame 130 may have other implementations. For example, the rear wheel frame 130 may include only two rear rods 131, one end of the two rear rods 131 being connected to form a V-shaped structure, and the cart 1000 may have a rear wheel seat 142 mounted on the end of the two rear rods 131. Alternatively, for example, the rear wheel frame 130 may include only two rear rods 131 arranged parallel to each other in the left-right direction, and the two rear wheel seats 142 may be connected to the two rear rods 131, respectively.

[0127] Referring to Figures 1 and 2, the handle frame 110 includes a first handle frame 111, a second handle frame 112 and two folding joints 113. The second handle frame 112 is pivotally connected to the first handle frame 111 by two folding joints 113 on the left and right sides, so that the first handle frame 111 can be unfolded (see Figure 3) or folded (see Figures 12 to 14) relative to the second handle frame 112. Specifically, the first handle frame 111 is, for example, a U-shaped structure as a whole, which includes a handle bar 1112 and two first support rods 1111. The two first support rods 1111 are arranged parallel to each other and spaced apart along a first direction F1. The handle bar 1112 is U-shaped and connected between the two first support rods 1111, for a user to hold to push the cart 1000. More specifically, the second push handle frame 112, for example, includes two second support rods 1121, and the two second support rods 1121 are spaced apart along the first direction F1. The upper ends of the two second support rods 1121 are, for example, respectively pivotally connected to the lower end of the first support rod 1111 on the same side through the retracting joint 113 on the same side, and the lower ends of the two second support rods 1121 are, for example, respectively connected to the first connecting seat 210 in the joint structure 200 on the same side.

[0128] Referring to Figures 4 to 6, in one embodiment, each folding joint 113 includes a fifth connecting seat 1131, a sixth connecting seat 1132, and a fourth locking member 1133. The fifth connecting seat 1131 is connected to the first push handle frame 111 (specifically, the first support rod 1111), the sixth connecting seat 1132 is connected to the second push handle frame 112 (specifically, the second support rod 1121), and the sixth connecting seat 1132 and the fifth connecting seat 1131 are pivotally connected to each other via a second pivot 1137 so that the first push handle frame 111 can be unfolded or folded relative to the second push handle frame 112. In order to prevent the first push handle frame 111 from rotating freely relative to the second push handle frame 112, in one embodiment, as shown in Figures 4 and 6, the sixth connecting seat 1132 is provided with a locking slot 11321, and the fourth locking member 1133 is movably arranged on the first push handle frame 111. When the first push handle frame 111 and the second push handle frame 112 are relatively deployed, the first push handle frame 111 is approximately parallel to the second push handle frame 112, that is, the first push handle frame 111 and the second push handle frame 112 are approximately in the same plane, and the angle between the first push handle frame 111 and the second push handle frame 112 is approximately 180 degrees (see Figures 2 and 3). At this time, the fourth locking member 1133 can be inserted into the locking slot 11321 to limit the pivoting of the first push handle frame 111 relative to the second push handle frame 112, thereby allowing the first push handle frame 111 to stably maintain relative deployment relative to the second push handle frame 112. When the fourth locking member 1133 is withdrawn from the locking slot 11321, the first push handle frame 111 can pivot and fold relative to the second push handle frame 112, and the angle between the first push handle frame 111 and the second push handle frame 112 is an acute angle (see Figures 13 and 14) or approaches 0 degrees. Of course, in other embodiments, when the cart 1000 is in the extended state, the angle between the first handle frame 111 and the second handle frame 112 may also be an obtuse angle or an acute angle, which is not specifically limited here.

[0129] To facilitate controlling the fourth locking member 1133 to retract from the locking groove 11321 so that the first handle frame 111 can be folded relative to the second handle frame 112, in one embodiment, as shown in Figures 1, 3, and 4, the handle frame 110 further includes a release button 161 and a second pulling member 162. The release button 161 is movably disposed on the first handle frame 111 and is connected to the fourth locking member 1133 via the second pulling member 162. When the release button 161 moves relative to the first handle frame 111, the release button 161 drives the fourth locking member 1133 to move relative to the first handle frame 111 via the second pulling member 162, allowing it to disengage from the locking groove 11321. The second pulling member 162 can be, for example, a traction rope, one end of which is connected to the release button 161 and the other end is connected to the fourth locking member 1133. Specifically, as shown in Figures 7 and 8, the release button 161 includes an operating portion 1612. The handle frame 110 further includes a driving wheel 1611, which is rotatably disposed on the first handle frame 111 and connected to one end of the second pulling member 162. The operating portion 1612 is movably disposed on the first handle frame 111 and connected to the driving wheel 1611, so that the release button 161 is indirectly connected to one end of the second pulling member 162 via the driving wheel 161. When the operating portion 1612 moves relative to the first handle frame 111, it drives the driving wheel 1611 to rotate relative to the first handle frame 111, thereby pulling the second pulling member 162 to move, causing the fourth locking member 1133 to exit the locking slot 11321.

[0130] Referring to Figures 3 and 4, in one embodiment, the handlebar frame 110 also includes a fourth elastic member 163 arranged on the first push handle frame 111. The fourth elastic member 163 is, for example, a compression spring and is against the fourth locking member 1133, and is used to drive the fourth locking member 1133 to reset so that the fourth locking member 1133 always has a tendency to be inserted into the lock slot 11321.

[0131] Referring to FIG. 8 , in one embodiment, the handlebar frame 110 further includes a safety push button 164 movably disposed on the first handlebar frame 111 and having a third position and a fourth position. When the safety push button 164 is in the third position, the safety push button 164 abuts against the release button 161 to prevent the release button 161 from moving relative to the first handlebar frame 111. Specifically, the safety push button 164 abuts against the operating portion 1612 to prevent the operating portion 1612 from moving relative to the first handlebar frame 111, thereby preventing the drive wheel 1611 from rotating to drive the second traction member 162. When the safety push button 164 is in the fourth position, the safety push button 164 is spaced apart from the release button 161, allowing the release button 161 to move relative to the first handlebar frame 111. The movement direction of the safety push button 164 intersects with the movement direction of the release button 161. Therefore, when the user wishes to pivot the first handle frame 111 relative to the second handle frame 112 for folding, the user must first operate (e.g., toggle) the safety button 164 to position the safety button 164 in the fourth position before operating (e.g., pressing) the operating portion 1612 to retract the fourth locking member 1133 from the locking slot 11321. This prevents the user from accidentally folding the handle frame 110 due to misoperation of the release button 161.

[0132] 6, 9 to 11, in one embodiment, each retractable joint 113 further includes a fifth locking member 1134. One of the fifth connecting seat 1131 and the sixth connecting seat 1132 is provided with a limiting recess 11322, and the other is provided with the fifth locking member 1134. The fifth locking member 1134 is movably disposed and has a first position and a second position. Specifically, in this embodiment, as shown in FIG6, the sixth connecting seat 1132 is provided with a limiting recess 11322, and the limiting recess 11322 is spaced apart from the locking groove 11321 along a circumferential direction around the second pivot 1137. The fifth locking member 1134 is movably disposed on the fifth connecting seat 1131. As shown in FIG11 , when the first handle frame 111 is folded relative to the second handle frame 112 and the fifth locking member 1134 is in the first position, the fifth locking member 1134 extends into the limiting recess 11322, thereby allowing the first handle frame 111 and the second handle frame 112 to remain folded relative to each other, preventing the first handle frame 111 from freely pivoting relative to the second handle frame 112 after the folding of the vehicle handle frame 110. As shown in FIG9 and FIG10 , when the fifth locking member 1134 is in the second position, the fifth locking member 1134 retracts from the limiting recess 11322, thereby allowing the first handle frame 111 to pivot relative to the second handle frame 112, thereby allowing the vehicle handle frame 110 to unfold.

[0133] 6, 10, and 11, in this embodiment, the folding joint 113 further includes a stopper 1135 and a third elastic member 1136. Specifically, the fifth connecting seat 1131 defines a movable hole 11311, and the fifth locking member 1134 is movably disposed within the movable hole 11311. The stopper 1135 is disposed on the side of the fifth connecting seat 1131 facing away from the sixth connecting seat 1132, and the third elastic member 1136 abuts between the stopper 1135 and the fifth locking member 1134 to maintain the fifth locking member 1134 in the first position.

[0134] Continuing with Figures 6, 10, and 11, in one embodiment, at least one of the end of the fifth locking member 1134 facing the limiting recess 11322 and the limiting recess 11322 is provided with a sliding inclined surface 11341 adapted to release the limiting position. Specifically, the end of the fifth locking member 1134 facing the limiting recess 11322 is provided with the sliding inclined surface 11341, and the inner wall of the limiting recess 11322 is also provided with the sliding inclined surface 11341. Thus, the fifth locking member 1134 can push against the limiting recess 11322 via the sliding inclined surface 11341, so that when the sixth connecting seat 1132 drives the limiting recess 11322 to rotate relative to the fifth connecting seat 1131, the fifth locking member 1134 can move out of the limiting recess 11322 in a direction away from the sixth connecting seat 1132, thereby equivalently moving the fifth locking member 1134 from the first position to the second position.

[0135] 3 to 11 , the use process and working principle of the folding joint 113 will be briefly described.

[0136] 3, 4, and 10, when the handlebar frame 110 is deployed, that is, when the first handlebar frame 111 and the second handlebar frame 112 are deployed relative to each other, the first handlebar frame 111 and the second handlebar frame 112 are approximately in the same plane, with an angle of approximately 180 degrees between them. At this time, the locking groove 11321 on the sixth connecting seat 1132 is aligned with the fourth locking member 1133. Under the action of the fourth elastic member 163, the fourth locking member 1133 is inserted into the locking groove 11321, thereby restricting the fifth connecting seat 1131 from pivoting relative to the sixth connecting seat 1132. Simultaneously, the fifth locking member 1134, under the action of the third elastic member 1136, abuts against the surface of the sixth connecting seat 1132.

[0137] 7 and 8 , when a user needs to fold the handle frame 110, they first toggle the safety knob 164 to the fourth position and then press upward on the operating portion 1612. The operating portion 1612 rotates the drive wheel 1611, thereby moving the second traction member 162, which in turn moves the fourth locking member 1133 away from the sixth connecting seat 1132, allowing the fourth locking member 1133 to retract from the locking slot 11321. At this point, the user can rotate the first handle frame 111 to fold the first handle frame 111 relative to the second handle frame 112. When the first push handle frame 111 is folded relative to the second push handle frame 112, the limiting recess 11322 is opposite to the fifth locking member 1134, and the third elastic member 1136 drives the fifth locking member 1134 to automatically insert into the limiting recess 11322 (see Figure 11). In this way, the first push handle frame 111 can be maintained in a relatively folded state relative to the second push handle frame 112.

[0138] 6 , 10 , and 11 , since both the fifth locking member 1134 and the position-limiting recess 11322 are provided with a sliding inclined surface 11341, when the user wishes to unfold the handle frame 110, the user can directly rotate the first handle frame 111. Guided by the sliding inclined surface 11341, the fifth locking member 1134 gradually moves relative to the position-limiting recess 11322 and gradually exits the position-limiting recess 11322. When the first handle frame 111 is unfolded relative to the second handle frame 112, the fourth elastic member 163 drives the fourth locking member 1133 into the locking slot 11321, thereby maintaining the handle frame 110 in the unfolded state.

[0139] 1 and 2 , in the joint structure 200 provided in the first embodiment, the first connecting seat 210, the second connecting seat 220 and the third connecting seat 230 are pivotally connected to each other at a first pivot (not shown in the figure, the axis extension direction of the first pivot is the axial direction). In this way, the axial movement of the first connecting seat 210, the second connecting seat 220 and the third connecting seat 230 can be limited, thereby avoiding the axial separation or disengagement of the three from each other, thereby improving the stability of the joint structure 200 and the cart 1000 structure.

[0140] Referring to Figures 15 to 18, in the first embodiment, the joint structure 200 further includes a first locking member 240, a second locking member 280 and a driving member 250. The first locking member 240 is axially movable and arranged between the first connecting seat 210 and the second connecting seat 220, and has a first locking position and a first unlocking position. Specifically, when the first locking member 240 is in the first locking position, the first connecting seat 210 and the second connecting seat 220 are relatively fixed. When the first locking member 240 is in the first unlocking position, the first connecting seat 210 can pivot relative to the second connecting seat 220. The second locking member 280 is axially movable and arranged in the joint structure 200 and is provided with at least one locking portion 281, and at least one locking portion 281 extends in a direction parallel to the axial direction. The second locking member 280 has a second locked position and a second unlocked position. When the second locking member 280 is in the second locked position, at least one locking portion 281 passes through the third connecting seat 230 and the second connecting seat 220 in a direction parallel to the axial direction, and the locking portion 281 is radially spaced from the first pivot. This restricts the second connecting seat 220 from rotating relative to the third connecting seat 230 about the first pivot, thereby keeping the second and third connecting seats 220 and 230 relatively fixed. When the second locking member 280 is in the second unlocked position, the locking portion 281 passes only through the third connecting seat 230 or the second connecting seat 220 in a direction parallel to the axial direction, allowing the second connecting seat 220 to pivot relative to the third connecting seat 230. The driving member 250 is disposed outside the first pivot and is rotatable about the first pivot. It is also axially movable between the first and second connecting seats 210 and 220, and has an initial position and an unlocked position. When the driving member 250 moves from the initial position to the unlocked position, the driving member 250 drives the first locking member 240 from the first locked position to the first unlocked position, and drives the second locking member 280 from the second locked position to the second unlocked position. Thus, by changing the position of the driving member 250, the positions of the first locking member 240 and the second locking member 280 can be changed, thereby changing the relative positions of the first connecting seat 210, the second connecting seat 220, and the third connecting seat 230, thereby enabling the stroller 1000 to switch between the extended state and the folded state.

[0141] It should be noted that the phrase "at least one locking portion 281" refers to the fact that the locking portion 281 may be one, two, or more. Furthermore, when multiple locking portions 281 are provided, the multiple locking portions 281 may be spaced apart circumferentially. Specifically, in this embodiment, the second locking member 280 includes a main body 282, from which the locking portions 281 extend in a direction parallel to the axial direction. More specifically, the main body 282 is annular, allowing the first pivot axis to pass through, with the first pivot axis located at the center of the main body 282. The second locking member 280 includes multiple locking portions 281, spaced apart along the circumferential edge of the main body 282. This simultaneous passage of multiple locking portions 281 through the third connecting base 230 and the second connecting base 220 further restricts the rotational movement of the second connecting base 220 relative to the third connecting base 230 about the first pivot axis, thereby enhancing the stability of the second locking member 280 locking the second connecting base 220 and the third connecting base 230.

[0142] 17 , the second locking member 280 is provided with a plurality of engaging portions 283 extending radially from the main body portion 282 , and the plurality of engaging portions 283 are arranged at intervals along the circumferential direction.

[0143] In this embodiment, the driving member 250 is disposed adjacent to the first locking member 240. When the driving member 250 moves from the initial position to the unlocked position, the driving member 250 directly drives the first locking member 240 to move from the first locked position to the first unlocked position. Simultaneously, when the first locking member 240 moves from the first locked position to the first unlocked position, the first locking member 240 directly drives the second locking member 280 to move from the second locked position to the second unlocked position. In other words, in this embodiment, when the driving member 250 moves from the initial position to the unlocked position, the driving member 250 directly drives the first locking member 240 to move from the first locked position to the first unlocked position. Simultaneously, the driving member 250 also indirectly drives the second locking member 280 to move from the second locked position to the second unlocked position via the first locking member 240.

[0144] 15 and 16 , in one embodiment, the driving member 250 is used to drive the first locking member 240 to move in the positive axial direction toward the second connecting seat 220, thereby reaching a first unlocked position. As shown in FIG19 , when the first locking member 240 is in the first locked position, the first locking member 240 engages with both the first connecting seat 210 and the second connecting seat 220, thereby maintaining relative fixity between the first connecting seat 210 and the second connecting seat 220. As shown in FIG20 , when the first locking member 240 is in the first unlocked position, the first locking member 240 engages with the second connecting seat 220 and disengages from the first connecting seat 210, thereby allowing the first connecting seat 210 to pivot relative to the second connecting seat 220. It should be noted that, in this embodiment, the first unlocked position of the first locking member 240 can be considered as the first locking member 240 being located within the second connecting seat 220.

[0145] Specifically, the first locking member 240 is a gear structure through which the first pivot shaft passes. As shown in Figures 21 and 22, the first connecting base 210 defines a generally annular first accommodating space 212 on one side facing the second connecting base 220, and a plurality of first locking grooves 213 circumferentially spaced around the periphery of the first accommodating space 212. The second connecting base 220 defines a generally annular second accommodating space 222 on one side facing the first connecting base 210, and a plurality of second locking grooves 223 circumferentially spaced around the periphery of the second accommodating space 222. When the first locking member 240 is in the first locking position, one axial end of the first locking member 240 is located within the first accommodating space 212, and the other end is located within the second accommodating space 222 (see Figure 19). Consequently, the plurality of protruding teeth on the outer periphery of the first locking member 240 are simultaneously received in the plurality of first locking grooves 213 and the plurality of second locking grooves 223 in a direction parallel to the axial direction. When the first locking member 240 is in the first unlocking position, the first locking member 240 is completely moved into the second accommodating space 222 (see FIG. 20 ), and the plurality of protruding teeth on the outer periphery of the first locking member 240 are only accommodated in the plurality of second locking grooves 223 along a direction parallel to the axial direction.

[0146] It should be noted that the “positive direction along the axial direction” refers to the direction of movement from the first connecting seat 210 to the third connecting seat 230 along the axial direction. Correspondingly, the direction of movement from the third connecting seat 230 to the first connecting seat 210 along the axial direction can be regarded as the negative direction along the axial direction.

[0147] Referring to Figures 16 to 18 , in this embodiment, the main portion 282 of the second locking member 280 is located on a side of the third connecting seat 230 facing away from the second connecting seat 220. When the second locking member 280 is in the second locked position, the locking portion 281 sequentially passes through the third connecting seat 230 and the second connecting seat 220 in a direction parallel to the axial direction. Therefore, when the first locking member 240 moves from the first locked position to the first unlocked position, the first locking member 240 drives the locking portion 281 to move in a direction parallel to the positive axial direction until the locking portion 281 disengages from the second connecting seat 220. In this way, the locking portion 281 only passes through the third connecting seat 230, thereby reaching the second unlocked position. It should be noted that in this embodiment, the second unlocked position of the second locking member 280 can be considered as the second locking member 280 being located only between the third connecting seat 230 and the fourth connecting seat 290 (see below) or only within the fourth connecting seat 290.

[0148] Referring to Figures 2 and 15 to 18, in one embodiment, the joint structure 200 further includes a fourth connecting seat 290 and a third locking member 310. The fourth connecting seat 290 and the third connecting seat 230 are pivotally connected to each other axially, i.e., the fourth connecting seat 290 is pivotally connected to the first pivot axis. The second connecting seat 220 and the third connecting seat 230 are both located between the first connecting seat 210 and the fourth connecting seat 290. The third locking member 310 is axially movable between the third connecting seat 230 and the fourth connecting seat 290 and has a third locked position and a third unlocked position. Specifically, when the third locking member 310 is in the third locked position, the third connecting seat 230 and the fourth connecting seat 290 are fixed relative to each other. When the third locking member 310 is in the third unlocked position, the third connecting seat 230 can pivot relative to the fourth connecting seat 290. When the driving member 250 moves from the initial position to the unlocked position, the driving member 250 drives the third locking member 310 from the third locked position to the third unlocked position.

[0149] Although in this embodiment, the first connecting base 210, the second connecting base 220, the third connecting base 230, and the fourth connecting base 290 all rotate about an axial direction, in other embodiments, the first connecting base 210 and the second connecting base 220 may rotate about a first axial direction, the second connecting base 220 and the third connecting base 230 may rotate about a second axial direction, and the third connecting base 230 and the fourth connecting base 290 may rotate about a third axial direction, wherein the first axial direction, the second axial direction, and the third axial direction are parallel to each other but not coaxial. Alternatively, the first connecting base 210, the second connecting base 220, and the third connecting base 230 may rotate about a first axial direction, while the fourth connecting base 290 and the third connecting base 230 may rotate about a second axial direction, wherein the first axial direction and the second axial direction are parallel to each other but not coaxial.

[0150] It should be noted that in this embodiment, the driver 250 indirectly drives the third locking member 310 from the third locked position to the third unlocked position. For example, the driver 250 indirectly drives the movement of the third locking member 310 via the second locking member 280. Specifically, as shown in Figures 17 and 18, the main body 282 of the second locking member 280 is located between the third locking member 310 and the third connecting base 230. When the second locking member 280 moves from the second locked position to the second unlocked position, the second locking member 280 directly drives the third locking member 310 from the third locked position to the third unlocked position (from Figure 19 to Figure 20). Therefore, in this embodiment, when the driver 250 moves from the initial position to the unlocked position, it directly drives the first locking member 240 out of the first locked position to reach the first unlocked position. Subsequently, through the unlocked first locking member 240, the driver 250 continues to indirectly move the second locking member 280 from the second locked position to the second unlocked position. Finally, through further transmission of the second locking member 280 , the third locking member 310 can move from the third locking position to the third unlocking position.

[0151] In one embodiment, when the locking portion 281 on the third locking member 310 moves away from the second connecting seat 220, the locking portion 281 drives the third locking member 310 to move in the positive axial direction to the fourth connecting seat 290 to the third unlocked position. In other words, the third unlocked position of the third locking member 310 can be considered as the third locking member 310 being located within the fourth connecting seat 290. Specifically, when the third locking member 310 is in the third locking position, the third locking member 310 is engaged with both the third connecting seat 230 and the fourth connecting seat 290. When the third locking member 310 is in the third unlocked position, the third locking member 310 is engaged with the fourth connecting seat 290 and is disengaged from the third connecting seat 230, allowing the fourth connecting seat 290 to pivot relative to the third connecting seat 230.

[0152] Specifically, the third locking member 310 is a gear structure through which the first pivot shaft passes. As shown in Figures 17, 19, and 20, the third connecting base 230 defines a generally annular third accommodating space 232 on one side facing the fourth connecting base 290, and a plurality of third locking grooves 233 circumferentially spaced around the third accommodating space 232. The fourth connecting base 290 defines a generally annular fourth accommodating space 291 on one side facing the third connecting base 230, and a plurality of fourth locking grooves 292 circumferentially spaced around the fourth accommodating space 291. When the third locking member 310 is in the third locked position, one axial end of the third locking member 310 is located within the third accommodating space 232, and the other end is located within the fourth accommodating space 291 (see Figure 19). Consequently, the plurality of protruding teeth on the outer periphery of the third locking member 310 are simultaneously received in the plurality of third locking grooves 233 and the plurality of fourth locking grooves 292 in a direction parallel to the axial direction. When the third locking member 310 is in the third unlocking position, the third locking member 310 is completely moved into the fourth accommodating space 291 (see Figure 20), and the multiple protruding teeth on the outer periphery of the third locking member 310 are only accommodated in the multiple fourth locking grooves 292 along the direction parallel to the axial direction.

[0153] Referring to Figures 15 to 18 , in one embodiment, a first elastic member 260 is disposed between the first locking member 240 and the second connecting base 220. The first elastic member 260 provides elastic restoring force to the first locking member 240, thereby maintaining the first locking member 240 in the first locked position. Thus, under the restoring force of the first elastic member 260, the first locking member 240 automatically moves from the first unlocked position to the first locked position, thereby causing the driving member 250 to move from the unlocked position to the initial position. Alternatively, the first elastic member 260 is a compression spring, with both ends abutting between the second connecting base 220 and the first locking member 240.

[0154] Continuing with Figures 15 to 18 , in one embodiment, a second elastic member 320 is disposed between the third locking member 310 and the fourth connecting base 290. The second elastic member 320 provides elastic restoring force to the third locking member 310, thereby maintaining the third locking member 310 in the third locked position. This allows the first elastic member 260 to automatically move the first locking member 240 from the first unlocked position to the first locked position. This releases the pressure exerted by the first locking member 240 on the second locking member 280, allowing the second elastic member 320 to automatically move the third locking member 310 from the third unlocked position to the third locked position. This in turn allows the second locking member 280 to move from the second unlocked position to the second locked position, ultimately limiting relative rotation between the first connecting base 210, the second connecting base 220, the third connecting base 230, and the fourth connecting base 290, thereby maintaining relative stability. Similarly, the second elastic member 320 may be a compression spring, with both ends abutting between the fourth connecting base 290 and the third locking member 310.

[0155] Referring to Figures 1, 2, and 19, in one embodiment, the stroller 1000 further includes a seat 170 (the specific structure of which will be described later), and the seat 170 is connected to the fourth connecting seat 290. Specifically, when the stroller 1000 is in the extended state, the seat 170 and the rear wheel frame 130 are arranged at a fifth angle α5 (see Figure 3). When the stroller 1000 is in the folded state, the seat 170 and the rear wheel frame 130 are arranged at a sixth angle (not shown), wherein the sixth angle is smaller than the fifth angle α5.

[0156] The following briefly describes the use process and working principle of the joint structure 200 with reference to relevant diagrams.

[0157] 3 and 19 , in this embodiment, when the cart 1000 is in the extended state, the driving member 250 is in the initial position, the first locking member 240 is in the first locking position, and the first connecting seat 210 and the second connecting seat 220 remain relatively fixed. Furthermore, the second locking member 280 is in the second locking position, and the locking portion 281 extends through the second connecting seat 220 and the third connecting seat 230 to maintain relative fixation between them. Furthermore, the third locking member 310 is in the third locking position, and the third connecting seat 230 and the fourth connecting seat 290 remain relatively fixed. Therefore, with the cooperation of the first locking member 240, the second locking member 280, and the third locking member 310, the cart 1000 can be stably maintained in the extended state.

[0158] When the stroller 1000 is to be switched from the extended state to the folded state (as shown in Figure 3, followed by Figures 12, 13, and 14), the driving member 250 is gradually moved toward the unlocked position. During this movement, the driving member 250 directly drives the first locking member 240 toward the first unlocked position. Simultaneously, the driving member 250 indirectly drives the second locking member 280 toward the second unlocked position via the first locking member 240. Furthermore, the driving member 250 indirectly drives the third locking member 310 toward the third unlocked position via the second locking member 280. When the driving member 250 reaches the unlocked position, the first locking member 240 is in the first unlocked position, the first elastic member 260 is compressed, and the first connecting seat 210 can rotate relative to the second connecting seat 220, thereby bringing the handlebar frame 110 and the front wheel frame 120 closer together. At the same time, the second locking member 280 is in the second unlocked position, and the locking portion 281 is retracted from the second connecting seat 220. This allows the second connecting seat 220 to rotate relative to the third connecting seat 230, thereby bringing the front wheel frame 120 and the rear wheel frame 130 closer together. Furthermore, the third locking member 310 is in the third unlocked position, and the second elastic member 320 is compressed, allowing the fourth connecting seat 290 to rotate relative to the third connecting seat 230, thereby bringing the seat 170 and the rear wheel frame 130 closer together.

[0159] When the stroller 1000 needs to be switched from the folded state to the extended state, the seat 170, rear wheel frame 130, front wheel frame 120, and rider frame 110 can be rotated to restore them to their corresponding positions when the stroller 1000 was in the extended state, thereby driving the corresponding connecting seats to rotate about the first pivot axis. During this process, the second elastic member 320 gradually returns to its original position and pushes the third locking member 310 to the third locking position, thereby securing the fourth connecting seat 290 relative to the third connecting seat 230. As the third locking member 310 moves to the third locking position, it pushes the second locking member 280 to the second locking position, effectively pushing the locking portion 281 through the third connecting seat 230 and the second connecting seat 220 in a direction parallel to the axial direction, thereby limiting the pivoting between the third connecting seat 230 and the second connecting seat 220. In addition, the first elastic member 260 gradually returns to its original position and pushes the first locking member 240 to move toward the first locking position, thereby limiting the pivoting between the second connecting seat 220 and the first connecting seat 210 .

[0160] As described above, when the stroller 1000 switches between the folded state and the extended state, the rider frame 110, the front wheel frame 120, the rear wheel frame 130 and the seat 170 connected to the joint structure 200 will rotate with the corresponding connecting seats, so that the stroller 1000 can switch between the extended state and the folded state.

[0161] To facilitate user control of the position of the driver 250, referring to Figures 6 and 16, in one embodiment, the driver 250 is connected to the handle frame 110 via a first traction member 270. Specifically, in this embodiment, the driver 250 is connected to the fifth connecting seat 1131 via the first traction member 270. More specifically, the first traction member 270 can be a traction rope, one end of which is connected to the fifth connecting seat 1131, and the other end of which is connected to the driver 250. Therefore, when the first push handle frame 111 pivots relative to the second push handle frame 112, the fifth connecting seat 1131 pivots relative to the sixth connecting seat 1132. In this way, the end of the traction rope connected to the fifth connecting seat 1131 rotates accordingly, thereby driving the driver 250 to rotate about the first pivot.

[0162] In order to achieve the conversion of the driving member 250 from rotational motion to axial motion, in one embodiment, as shown in Figures 16 and 21, the driving member 250 is provided with an abutment portion 251, which protrudes in a direction parallel to the axial direction and extends obliquely in the circumferential direction. The first connecting seat 210 is provided with a push portion 214, which protrudes in a direction parallel to the axial direction and extends obliquely in the circumferential direction. Specifically, the push portion 214 is formed to protrude from the bottom wall of the first accommodating space 212 in the first connecting seat 210 toward the driving member 250. The abutment portion 251 and the push portion 214 abut against each other in a direction parallel to the axial direction. Specifically, when the cart 1000 is in the extended state, the abutment portion 251 and the push portion 214 fit together. When the pushcart 1000 switches from the extended state to the folded state, the first handle frame 111 pivots relative to the second handle frame 112 about the second pivot 1137 (switching from FIG. 3 to FIG. 12 ). During this process, the fifth connecting seat 1131 drives one end of the first pulling member 270 to rotate about the second pivot 1137, thereby driving the driving member 250 to rotate circumferentially around the first pivot relative to the first connecting seat 210. Under the mutual push of the abutting portion 251 and the pushing portion 214, the driving member 250 can move in the positive axial direction, thereby moving the driving member 250 from the initial position to the unlocked position.

[0163] In this embodiment, when the user needs to fold the stroller 1000, the user first pushes the safety push button 164 to move the safety push button 164 to the fourth position. Then, the user operates the release button 161 to drive the fourth locking member 1133 to retract from the lock slot 11321. In this way, the first handle frame 111 and the second handle frame 112 can be folded by rotating the first handle frame 111. During this process, the fifth connecting seat 1131 rotates about the second pivot 1137, thereby driving the first pulling member 270 to move, and ultimately causing the driving member 250 to rotate about the first pivot. Because the driving member 250 is provided with an abutting portion 251, when the driving member 250 rotates, the abutting portion 251 abuts against the pushing portion 214 on the first connecting seat 210, thereby driving the driving member 250 to move in the positive axial direction to switch to the unlocked position. As described above, when the driving member 250 is in the unlocked position, the first locking member 240 is in the first unlocked position, the second locking member 280 is in the second unlocked position, and the third locking member 310 is in the third unlocked position. At this point, the first connecting base 210 can rotate relative to the second connecting base 220, the second connecting base 220 can rotate relative to the third connecting base 230, and the third connecting base 230 can rotate relative to the fourth connecting base 290. In this way, the stroller 1000 can switch from the extended state to the folded state.

[0164] In one embodiment, the first connecting seat 210 is provided with a first limiting post 211 extending in a direction parallel to the axial direction (see FIG. 21 ), the second connecting seat 220 is provided with a second limiting post 221 extending in a direction parallel to the axial direction (see FIG. 16 and FIG. 22 ), and the third connecting seat 230 is provided with a third limiting post 231 extending in a direction parallel to the axial direction (see FIG. 17 and FIG. 23 ). The first limiting post 211, the third limiting post 231, and the second limiting post 221 are arranged sequentially along the circumferential direction. When the cart 1000 is in the extended state, the first connecting seat 210, the second connecting seat 220, and the third connecting seat 230 are relatively fixed, and the third limiting post 231 abuts at least one of the first limiting post 211 and the second limiting post 221. Specifically, in this embodiment, as shown in FIG. 3 , the third limiting post 231 abuts each of the first limiting post 211 and the second limiting post 221. In this way, the third connecting seat 230 can be fixed relative to the second connecting seat 220 and the first connecting seat 210, respectively. That is, the third connecting seat 230 cannot rotate relative to the second connecting seat 220, and at the same time, the third connecting seat 230 cannot rotate relative to the first connecting seat 210. As can be seen, when the cart 1000 is in the extended state, the second locking member 280 can ensure the relative fixation between the second connecting seat 220 and the third connecting seat 230. In addition, the mutual abutment between the third limiting post 231 and the first limiting post 211 and the second limiting post 221 further ensures the stable fixation of the second connecting seat 220 relative to the third connecting seat 230. This can improve the stability and reliability of the cart 1000 in the extended state. As shown in Figure 14, when the cart 1000 is in the folded state, the first limiting post 211, the third limiting post 231, and the second limiting post 221 are sequentially spaced along the circumference, and the third connecting seat 230 can pivot relative to the first connecting seat 210 and the second connecting seat 220.

[0165] Specifically, as shown in Figures 16, 17, and 21 to 23, in this embodiment, the first limiting post 211 protrudes toward the second connecting seat 220 in a direction parallel to the axial direction, the second limiting post 221 protrudes toward the first connecting seat 210 in a direction parallel to the axial direction, and the third limiting post 231 protrudes toward the first connecting seat 210 in a direction parallel to the axial direction and passes through the second connecting seat 220. More specifically, the second connecting seat 220 is provided with a movable groove 224 for the third limiting post 231 to move circumferentially, and the movable groove 224 has an arc-shaped structure. The first limiting post 211 and the third limiting post 231 are capable of circumferential movement within the second connecting seat 220. Specifically, when the cart 1000 is in the folded state, the third limiting post 231 circumferentially abuts against the groove wall of the movable groove 224 on the side away from the second limiting post 221 (see Figure 14).

[0166] It should be noted that the first limiting post 211 protrudes toward the second connecting seat 220 and is spaced axially therefrom. Specifically, the first limiting post 211 protrudes from the bottom wall of the first accommodating space 212 within the first connecting seat 210 toward the second connecting seat 220. The second limiting post 221 protrudes toward the first connecting seat 210 and is spaced axially therefrom. Specifically, the second limiting post 221 protrudes from the bottom wall of the second accommodating space 222 within the second connecting seat 220 toward the first connecting seat 210. The third limiting post 231 protrudes toward the first connecting seat 210 and passes through the second connecting seat 220, and is spaced axially therefrom. Specifically, the third limiting post 231 protrudes from the surface of the third connecting seat 230 facing the second connecting seat 220 toward the first connecting seat 210. The fact that the first limiting post 211, the second limiting post 221, and the third limiting post 231 all extend parallel to the axial direction is merely a preferred embodiment.

[0167] 3 , 13 , and 14 , in one embodiment, the first locking member 240 and the driving member 250 are both located radially to one side of the first limiting post 211, the second limiting post 221, and the third limiting post 231. Specifically, the first locking member 240 and the driving member 250 are both located radially outward of the first limiting post 211, the second limiting post 221, and the third limiting post 231. This means that the first locking member 240 and the driving member 250 are both movably sleeved on the outside of the first limiting post 211, the second limiting post 221, and the third limiting post 231. This prevents interference between the axial movement or rotation about the axial direction of the first locking member 240 and the driving member 250 and the circumferential movement of the limiting posts.

[0168] To ensure that the stroller 1000 remains stably in the folded state after folding, as shown in Figures 21 and 22, in one embodiment, the first connecting seat 210 is provided with a first engaging member 215, and the second connecting seat 220 is provided with a second engaging member 225. Specifically, the first engaging member 215 and the second engaging member 225 are both circumferentially located between the first limiting post 211 and the second limiting post 221, and are located on the side of the first limiting post 211 and the second limiting post 221 circumferentially away from the third limiting post 231. When the stroller 1000 is in the folded state, the first engaging member 215 and the second engaging member 225 engage with each other. Specifically, the first engaging member 215 abuts against the second engaging member 225 on the side of the second engaging member 225 closer to the second limiting post 221 (see Figure 14). In this way, the first connecting seat 210 can remain fixed after rotating relative to the second connecting seat 220, thereby restricting the hand frame 110 from moving away from the rear wheel frame 130. When the cart 1000 is in the extended state, the first engaging member 215 is located on a side of the second engaging member 225 close to the first limiting column 211 and is spaced apart from the second engaging member 225 (see FIG. 3 ).

[0169] 3 , 14 , 21 , and 22 , in one embodiment, the second engaging member 225 is a locking protrusion that protrudes toward the first connecting seat 210 in a direction parallel to the axial direction and is provided with a locking portion 2255. Specifically, the second engaging member 225 protrudes from the bottom wall of the second accommodating space 222 within the second connecting seat 220 toward the first connecting seat 210. The first engaging member 215 includes an elastic arm 2151 and a convex bump 2153. A hollowed-out deformation portion 2152 is formed in the middle of the elastic arm 2151. The deformation portion 2152 imparts elastic force to the elastic arm 2151 for radially deforming. The convex bump 2153 is located radially inward of the elastic arm 2151. When the cart 1000 is in the folded state, the elastic arm 2151 is at least partially located radially outward of the second engaging member 225, and the protrusion 2153 abuts the second engaging member 225 on the side of the second engaging member 225 that is closer to the second limiting post 221. Specifically, at least one of the protrusion 2153 and the engaging projection is provided with a guide slope 2256. Thus, when the cart 1000 switches from the extended state to the folded state, the first connecting seat 210 rotates circumferentially relative to the second connecting seat 220, and the guide slope 2256 guides the first engaging member 215 from the side of the second engaging member 225 that is closer to the first limiting post 211 to the side of the second engaging member 225 that is closer to the second limiting post 221. More specifically, the first connection seat 210 has a ridge portion 217 that protrudes toward the second connection seat 220. Specifically, the ridge portion 217 protrudes from the bottom wall of the first accommodating space 212 within the first connection seat 210 toward the second connection seat 220. The ridge portion 217 is arranged axially, that is, the ridge portion 217 is arranged along the circumference. The first engaging portion 215 is disposed on the inner circumference of the ridge portion 217 and protrudes toward the axial position. Specifically, the elastic arm 2151 is connected to the inner circumference of the ridge portion 217, and the first limiting column 211 is also connected to the inner circumference of the ridge portion 217. More specifically, the engaging protrusion has a generally cubic structure, including an inner wall 2251 and an outer wall 2252 arranged in the radial direction, and a first side wall 2253 and a second side wall 2254 connected between the inner wall 2251 and the outer wall 2252. The arc-shaped transition between the outer wall 2252 and the first side wall 2253 forms a guide slope 2256, and the arc-shaped transition between the outer wall 2252 and the second side wall 2254 forms a locking portion 2255. As shown in Figures 3, 13, and 14, when the vehicle frame 1000 switches from the extended state to the folded state, the first connecting seat 210 rotates clockwise about the first pivot axis, causing the first locking member 215 to gradually approach and engage with the second locking member 225. During this process, the protrusion 2153 gradually abuts the guide slope 2256 and moves toward the outer wall 2252. During this abutment, the protrusion 2153 is squeezed, causing the elastic arm 2151 to deform and become concave toward the deformation portion 2152.When the protrusion 2153 passes over the outer wall 2252 and reaches the engaging portion 2255, the elastic arm 2151 returns to its original position to engage the protrusion 2153 with the engaging portion 2255. Thus, when the cart 1000 is in the folded state, in the absence of or minimal external force, the first connecting seat 210 and the second connecting seat 220 can remain relatively fixed, preventing the handlebar frame 110 from pivoting freely relative to the front wheel frame 120.

[0170] 3, 13 and 14, when the cart 1000 is converted from the extended state to the folded state, the hand frame 110 is first rotated toward the front wheel frame 120, so that the first limiting post 211 moves in the positive direction of the circumferential direction toward the side away from the third limiting post 231 (that is, the direction in which the first limiting post 211 moves in the circumferential direction toward the side away from the third limiting post 231 is the positive direction of the circumferential direction). At the same time, the hand frame 110 gradually rotates toward the direction close to the rear wheel frame 130. When the frame 110 abuts against the rear wheel frame 130, it will push the rear wheel frame 130 to move together toward the front wheel frame 120, so that the third limiting column 231 moves along the positive direction of the circumference toward the groove wall of the movable groove 224 away from the second limiting column 221 until the convex bump 2153 is engaged with the engaging portion 2255 along the positive direction of the circumference, and the third limiting column 231 abuts against the groove wall of the movable groove 224 away from the second limiting column 221 along the positive direction of the circumference, and the cart 1000 reaches the folded state.

[0171] 3, 13 and 14, when the cart 1000 is converted from the folded state to the extended state, the hand frame 110 is first rotated in the direction away from the front wheel frame 120, so that the first limiting post 211 moves toward the third limiting post 231 in the opposite direction of the circumference (that is, the direction in which the first limiting post 211 moves toward the third limiting post 231 in the circumferential direction is the opposite direction of the circumferential direction), and at the same time, the convex bump 2153 is also disengaged from the engaging portion 2255 in the opposite direction of the circumferential direction until the first limiting post 211 abuts against the third limiting post in the opposite direction of the circumferential direction. The first limiting post 211 can push the third limiting post 231 in the opposite circumferential direction, so that the third limiting post 231 can slide in the opposite circumferential direction within the movable groove 224 toward the groove wall of the movable groove 224 on the side close to the second limiting post 221 until the first locking member 240 is in the first locking position, thereby fixing the relative positional relationship between the first limiting post 211 and the second limiting post 221. The third limiting post 231 will at least abut against the first limiting post 211 in the circumferential direction, and the cart 1000 will now reach the extended state. In the embodiment shown in FIG3 , when the cart 1000 reaches the extended state, the third limiting post 231 also abuts against the second limiting post 221 in the circumferential direction, that is, the third limiting post 231 is circumferentially clamped between the first limiting post 211 and the third limiting post 231.

[0172] 2 , in one embodiment, a first blocking portion 226 is provided on the outer side of the second connecting seat 220, and a second blocking portion 234 is provided on the outer side of the third connecting seat 230. When the driving member 250 is in the unlocked position, the first locking member 240 is in the first released position, and the rear wheel frame 130 is circumferentially spaced from the front wheel frame 120, the first blocking portion 226 and the second blocking portion 234 abut against each other circumferentially to maintain the angle between the front wheel frame 120 and the rear wheel frame 130 at the first angle α1. This prevents the front and rear wheel frames 120, 130 from pivoting relative to each other after the first handle frame 1111 is folded downward, thereby preventing the front and rear wheel frames 120, 130 from being horizontally deployed (i.e., the angle between the front and rear wheel frames 120, 130 is close to 180 degrees), thereby affecting the folding effect. At the same time, the first blocking portion 226 and the second blocking portion 234 abut against each other along the circumferential direction, and can also be used to indicate to the user that the front wheel frame 120 and the rear wheel frame 130 are in a position for the second locking member 280 to be axially inserted into the second connecting seat 220 and the third connecting seat 230. Continuing with FIG2 , specifically, the first blocking portion 226 is provided on the outer periphery of the second connecting seat 220, extending toward the third connecting seat 230 in a direction parallel to the axial direction and protruding relative to the outer periphery of the second connecting seat 220. The second blocking portion 234 is provided on the outer periphery of the third connecting seat 230, extending toward the second connecting seat 220 in a direction parallel to the axial direction and protruding relative to the outer periphery of the third connecting seat 230.

[0173] Continuing with FIG2 , in one embodiment, a third blocking portion 235 is further provided on the periphery of the third connecting seat 230, and a fourth blocking portion 293 is provided on the periphery of the fourth connecting seat 290. The third blocking portion 235 and the fourth blocking portion 293 abut against each other along the circumferential direction to indicate to the user that the seat 170 and the rear wheel frame 130 are in a position where the third locking member 310 can axially engage with the third connecting seat 235 and the fourth connecting seat 290. Specifically, the third blocking portion 235 extends toward the fourth connecting seat 290 in a direction parallel to the axial direction and protrudes outward relative to the periphery of the third connecting seat 230, while the fourth blocking portion 293 extends toward the third connecting seat 230 in a direction parallel to the axial direction and protrudes outward relative to the periphery of the fourth connecting seat 290.

[0174] Referring again to Figure 2 , in one embodiment, the second blocking portion 234 and the third blocking portion 235 are disposed opposite and connected to each other in a direction parallel to the axial direction. Of course, in other embodiments, the second blocking portion 234 and the third blocking portion 235 may be integrally formed, or the second blocking portion 234 and the third blocking portion 235 may be spaced apart and not connected to each other. When the front wheel frame 120 and the rear wheel frame 130 are arranged at a first angle α1 and the seat 170 and the rear wheel frame 130 are arranged at a fifth angle α5, the first blocking portion 226 and the fourth blocking portion 293 are disposed opposite and parallel to the axial direction.

[0175] Referring to Figures 18 and 24, in one embodiment, the seat 170 includes a seat plate 171, a folding strap 172 passing through the seat plate 171, and a reeling mechanism 173 connected to both ends of the folding strap 172. The two ends of the folding strap 172 respectively pass through the seat plate 171 to extend from the first surface of the seat plate 171 to the second surface, and are connected to the reeling mechanism 173 disposed on the second surface. The reeling mechanism 173 automatically tightens the folding strap 172, and the first surface and the second surface are disposed opposite each other. It should be noted that in this embodiment, the first surface refers to the surface used to support the child's buttocks. When the stroller 1000 is in the extended state, the second surface faces the ground. Arranging the reeling mechanism 173 on the second surface can prevent the reeling mechanism 173 from occupying the child's riding space. When the stroller 1000 is in the folded state and the user needs to carry the stroller 1000 on their back, the user can directly pull the foldable shoulder strap 172, causing the foldable shoulder strap 172 to automatically extend from the retracting mechanism 173. The extended foldable shoulder strap 172 can then be carried or carried by the user. When the stroller 1000 does not need to be moved, the retracting mechanism 173 automatically tightens the foldable shoulder strap 172, effectively automatically retracting the foldable shoulder strap 172. This prevents excess foldable shoulder strap 172 from leaking onto the seat 171 and affecting the child's comfort.

[0176] Specifically, referring to Figures 25 and 26 , the reeling mechanism 173 includes a reel 1731 and a coil spring 1732. One end of the coil spring 1732 is fixedly connected to the second surface, and the reel 1731 is sleeved around the coil spring 1732 and connected to the other end of the coil spring 1732. In this way, the reel 1731 can rotate as the coil spring 1732 is reeled. Specifically, the two ends of the retractable shoulder strap 172 pass through the seat plate 171 and are respectively connected to the reel 1731. The connection points between the two ends of the retractable shoulder strap 172 and the reel 1731 are arranged relative to each other along the circumferential direction of the reel 1731. More specifically, in this embodiment, two openings 17311 are provided in the circumference of the reel 1731, and the ends of the folding strap 172 pass through the two openings 17311 respectively to form a knot 1721 (for example, a spherical knot or a bow knot, etc.). In this way, the knot 1721 can be engaged with the edge of the opening 17311 to connect the folding strap 172 to the reel 1731.

[0177] 24 and 25 , in one embodiment, the reel mechanism 173 further includes a shielding cover 1733. The shielding cover 1733 is generally circular and is primarily configured to cover the reel 1731 and coil spring 1732 to prevent leakage of the reel 1731 and coil spring 1732. This not only improves the aesthetics of the stroller 1000 but also prevents users or children from accidentally touching the reel 1731 and coil spring 1732. Of course, in other embodiments, the shielding cover 1733 can also be a structure of other shapes. As shown in Figures 27 and 28, the shielding cover 1733 includes a main cover body 17331 and an auxiliary cover body 17332. The main cover body 17331 is generally circular, and its inner cavity is used to accommodate the reel 1731 and the coil spring 1732. The auxiliary cover body 17332 is generally strip-shaped, and its inner cavity is used to accommodate the portion of the folding strap 172 exposed on the second surface, that is, the auxiliary cover body 17332 is used to cover the portion of the folding strap 172 located on the second surface. The auxiliary cover body 17332 is connected to the main cover body 17331, and the inner cavity of the auxiliary cover body 17332 is connected to the inner cavity of the main cover body 17331. It should be noted that in this embodiment, the auxiliary cover body 17332 is extended substantially along the extension direction of the folding strap 172 on the second surface.

[0178] Referring to Figure 28, in one embodiment, the winding mechanism 173 further includes a guide wheel 1734 and a steering wheel 1735, both of which are rotatably disposed on the second surface of the seat plate 171. The working principles of the guide wheel 1734 and the steering wheel 1735 are briefly described below using one end of the folding strap 172 as an example. Specifically, the rotation axis of the guide wheel 1734 is approximately parallel to the second surface of the seat plate 171, and the rotation axis of the steering wheel 1735 is approximately perpendicular to the second surface of the seat plate 171. Both are located on the folding path of the folding strap 172. It should be noted that the rotation axis of the steering wheel 1735 is parallel to the rotation axis of the reel 1731 and the coil spring 1732. After passing through the seat plate 171, one end of the folding strap 172 first passes through the gap between the guide wheel 1734 and the second surface, thereby reducing friction on the folding strap 172 and facilitating its movement and guidance. It then passes around the steering wheel 1735 and enters the opening 17311 of the reel 1731 to connect with the reel 1731. Because the rotation axes of the guide wheel 1734 and the steering wheel 1735 are perpendicular, the folding strap 172 gradually switches from being parallel to the second surface to being perpendicular to the second surface during its movement from the guide wheel 1734 to the steering wheel 1735. After passing through the steering wheel 1735, the folding strap 172 becomes tangential to the rotation of the reel 1731, facilitating reeling.

[0179] Continuing with FIG. 28 , in one embodiment, the reeling mechanism 173 further includes at least one set of guide ribs 1736. Each set of guide ribs 1736 includes two opposing guide ribs 1736, with the reeling strap 172 threaded between the two guide ribs 1736. Specifically, a set of guide ribs 1736 is provided between the guide wheel 1734 and the steering wheel 1735. These guide ribs 1736 assist in reeling the reeling strap 172 from a position parallel to the second surface to a position perpendicular to the second surface. Furthermore, a set of guide ribs 1736 is also provided between the steering wheel 1735 and the reel 1731. These guide ribs 1736 assist in reeling the reeling strap 172 onto the reel 1731.

[0180] Referring to FIG. 29 , a second embodiment of the present invention provides a joint structure 200 . This joint structure 200 can be considered a variation of the joint structure 200 of the first embodiment, with the main difference being that the second locking member 280 , the third locking member 310 , and the second elastic member 320 are omitted, and the third connecting seat 230 and the fourth connecting seat 290 are connected to form a single component (which can be referred to as a rotating seat 330 ). Unless there is a conflict, the working principles of the various components of the joint structure 200 can be found in the working principles of the corresponding components of the joint structure 200 of the first embodiment described above, and will not be repeated here. In this way, the joint structure 200 can still be expanded and folded, and therefore, the cart 1000 using this joint structure 200 can also switch between an extended state and a folded state. It should be noted that in the cart 1000 adopting the joint structure 200 shown in the second embodiment, the rider frame 110 is connected to the first connecting seat 210, the front wheel frame 120 is connected to the second connecting seat 120, the rear wheel frame 130 is connected to the rotating seat 330, and the seat 170 is pivotally connected to both the front wheel frame 120 and the rear wheel frame 130. When the rear wheel frame 130 moves closer to the front wheel frame 120, the seat 170 is driven to pivot simultaneously relative to the front wheel frame 120 and the rear wheel frame 130 to be folded.

[0181] The third embodiment of the present invention provides a joint structure 200 (not shown). This joint structure 200 can also be considered a variation of the joint structure 200 of the first embodiment, differing primarily in that the first limiting post 211, the second limiting post 221, and the third limiting post 231 are omitted. The relative fixation and pivoting between the second connecting seat 220 and the third connecting seat 230 are achieved solely by a second locking member 280. Therefore, unless there is a conflict, the operating principles of the various components of this joint structure 200 can be referenced to the corresponding operating principles of the joint structure 200 of the first embodiment described above and will not be further elaborated here.

[0182] The fourth embodiment of the present invention provides a joint structure 200 (not shown in the figures), which can also be regarded as a variation of the joint structure 200 in the first embodiment, with the main difference being that the third locking member 310 is omitted, the third connecting seat 230 and the fourth connecting seat 290 are connected to form a component (which can be called a rotating seat 330), the second locking member 280 is movably arranged in the rotating seat 330, and the second elastic member 320 abuts between the inner wall of the rotating seat 330 and the second locking member 280, so that the locking portion 281 of the second locking member 280 has a constant tendency to pass through the rotating seat 330 to be inserted into the second connecting seat 220. Therefore, in the absence of conflict, the working principles of the various components in the joint structure 200 can refer to the working principles of the corresponding components in the joint structure 200 of the first embodiment above, and will not be repeated here. It should be noted that in the cart 1000 adopting the joint structure 200 shown in the fourth embodiment, the rider frame 110 is connected to the first connecting seat 210, the front wheel frame 120 is connected to the second connecting seat 220, the rear wheel frame 130 is connected to the rotating seat 330, and the seat 170 is pivotally connected to both the front wheel frame 120 and the rear wheel frame 130. When the rear wheel frame 130 moves closer to the front wheel frame 120, the seat 170 is driven to pivot simultaneously relative to the front wheel frame 120 and the rear wheel frame 130 to be folded.

[0183] The fifth embodiment of the present invention provides a joint structure 200 (not shown). This joint structure 200 can also be considered a variation of the joint structure 200 of the first embodiment, with the main difference being that when the second locking member 280 is in the second locked position, the second locking member 280 sequentially passes through the third connecting seat 230, the second connecting seat 220, and the first locking member 240 before directly abutting against the driving member 250. Thus, when the driving member 250 moves from the initial position to the unlocked position, the driving member 250 can directly drive the first locking member 240 from the first locked position to the first unlocked position, and can also directly drive the second locking member 280 from the second locked position to the second unlocked position.

[0184] Referring to Figure 30, the sixth embodiment of the present invention provides a joint structure 200, which can also be regarded as a variation of the joint structure 200 in the first embodiment. The main difference is that the driving member 250 is located between the first locking member 240 and the second connecting seat 220, and the second locking member 280 is located between the driving member 250 and the first locking member 240. The locking portion 281 of the second locking member 280 is radially spaced from the abutting portion 251 of the driving member 250, and the locking portion 281 protrudes toward the second connecting seat 220 in a direction parallel to the axial direction; the first elastic member 260 abuts between the first locking member 240 and the first connecting seat 210. In the absence of conflict, the working principles of the various components in the joint structure 200 can be referred to the working principles of the corresponding components in the joint structure 200 of the first embodiment above, and will not be repeated here. The following mainly describes the differences between this embodiment and the above-mentioned first embodiment.

[0185] Specifically, in this embodiment, when the driving member 250 is in the initial position, the driving member 250 is located in the second connecting seat 220, the first locking member 240 is in the first locking position, and the first locking member 240 is engaged with the first connecting seat 210 and the second connecting seat 220 at the same time; the second locking member 280 is in the second locking position, the locking portion 281 passes over the periphery of the driving member 250, and passes through the second connecting seat 220 and the third connecting seat 230 in turn, and abuts against the third locking member 310, so that the third locking member 310 is in the third locking position, even if the third locking member 310 is engaged with the third connecting seat 230 and the fourth connecting seat 290 at the same time.

[0186] When the driving member 250 moves from the initial position to the unlocked position, the driving member 250 drives the second locking member 280 and the first locking member 240 to move in the anti-axial direction, disengaging the locking portion 281 of the second locking member 280 from the third connecting seat 230 and simultaneously moving the first locking member 240 into the first connecting seat 210 to reach the first unlocked position. During the movement parallel to the anti-axial direction, the locking portion 281 gradually ceases contact with the third locking member 310. Under the restoring action of the second elastic member 320, the second elastic member 320 drives the third locking member 310 into the third connecting seat 230 to reach the third unlocked position. It should be noted that in this embodiment, the first unlocked position of the first locking member 240 is located within the first connecting seat 210, and the third unlocked position of the third locking member 310 is located within the third connecting seat 230. The first pulling member 270 is disposed within the front wheel frame 120 through the second connecting seat 220.

[0187] When the driving member 250 moves from the unlocked position to the initial position, the second locking member 280 and the first locking member 240 are no longer abutted by the driving member 250, and a movable gap is left between the driving member 250 and the second locking member 280. Therefore, under the action of the first elastic member 260, the first locking member 240 is pushed back to the first locking position to maintain the first connecting seat 210 and the second connecting seat 220, while the second locking member 280 is pushed back to the second locking position to maintain the second connecting seat 220 and the third connecting seat 230. When the second locking member 280 is in the second locking position, the locking portion 281 passes over the periphery of the driving member 250, passes through the second connecting seat 220 and the third connecting seat 230 in sequence, and pushes the third locking member 310 to be in the third locking position, thereby ultimately maintaining the third connecting seat 230 and the fourth connecting seat 290.

[0188] Referring to FIG31 , the seventh embodiment of the present invention provides a joint structure 200, which can be regarded as a variation of the joint structure 200 in the sixth embodiment described above. The main difference is that the third locking member 310 and the second elastic member 320 are omitted, and the third connecting seat 230 and the fourth connecting seat 290 are connected to form a component (which can be called a rotating seat 330). Similarly, when the driving member 250 is in the initial position, the first locking member 240 is in the first locking position, and the first locking member 240 is engaged with the first connecting seat 210 and the second connecting seat 220 at the same time; the second locking member 280 is in the second locking position, and the locking portion 281 sequentially passes over the periphery of the driving member 250 and passes through the second connecting seat 220 to enter the rotating seat 330. In the absence of conflict, the working principles of the various components in the joint structure 200 can be referred to the working principles of the corresponding components of the joint structure 200 in the first embodiment and the sixth embodiment, and will not be repeated here. In this way, the joint structure 200 can still be expanded and folded, and therefore, the stroller 1000 using the joint structure 200 can also switch between an extended state and a folded state. It should also be noted that in the stroller 1000 using the joint structure 200 shown in the seventh embodiment, the rider frame 110 is connected to the first connecting seat 210, the front wheel frame 120 is connected to the second connecting seat 120, the rear wheel frame 130 is connected to the rotating seat 330, and the seat 170 is pivotally connected to both the front wheel frame 120 and the rear wheel frame 130. When the rear wheel frame 130 moves closer to the front wheel frame 120, it drives the seat 170 to pivot simultaneously relative to the front wheel frame 120 and the rear wheel frame 130 to achieve folding.

[0189] 32 , an eighth embodiment of the present invention provides a joint structure 200, which can be considered a variation of the joint structure 200 of the first embodiment, with the main difference being that the third locking member 310 is omitted, and the third connecting seat 230 and the fourth connecting seat 290 are connected to form a single component (which may be referred to as a rotating seat 330). Furthermore, the driving member 250 is located between the first locking member 240 and the second connecting seat 220, and the second locking member 280 is located between the driving member 250 and the second connecting seat 220. The locking portion 281 of the second locking member 280 protrudes toward the second connecting seat 220 in a direction parallel to the axial direction. A second elastic member 320 (not shown in FIG. 32 ) is located in the rotating seat 330 to abut against the locking portion 281, so that the locking portion 281 has a constant tendency to retreat from the rotating seat 330. The first elastic member 260 abuts between the first connecting seat 210 and the first locking member 240. Therefore, unless there is any conflict, the working principles of the various components in the joint structure 200 can refer to the working principles of the corresponding components in the joint structure 200 of the first embodiment, and will not be repeated here. The following mainly describes the differences between this embodiment and the first embodiment.

[0190] Specifically, in this embodiment, when the driving member 250 is in the initial position, the driving member 250 is located in the second connecting seat 220, the first locking member 240 is in the first locking position, and the first locking member 240 is engaged with the first connecting seat 210 and the second connecting seat 220 at the same time; the second locking member 280 is in the second locking position, and the locking portion 281 passes through the second connecting seat 220 in sequence and enters the rotating seat 330 to resist the second elastic member 320 in the rotating seat 330.

[0191] When the driving member 250 moves from the initial position to the unlocked position, the driving member 250 drives the first locking member 240 to move in the reverse axial direction, causing the first locking member 240 to move into the first connecting seat 210, thereby reaching the first unlocked position. Since the driving member 250 gradually stops contacting the second locking member 280 during its reverse axial movement, and a clearance exists between the driving member 250 and the second locking member 280, the second elastic member 320 can retract the locking portion 281 of the second locking member 280 from the rotating seat 330 under the resetting action of the second elastic member 320. It should be noted that in this embodiment, the first unlocked position is located within the first connecting seat 210, and the first pulling member 270 is disposed within the front wheel frame 120 via the second connecting seat 220.

[0192] When the driving member 250 moves from the unlocked position to the initial position, the driving member 250 pushes the second locking member 280 to move along the positive axial direction to the second locked position. The locking portion 281 passes through the second connecting seat 220 and enters the rotating seat 330 to abut against the second elastic member 320, thereby maintaining relative fixation between the second connecting seat 220 and the rotating seat 330. In addition, after the driving member 250 moves to the initial position, the first locking member 240 is no longer pressed by the driving member 250. Since there is a movable gap between the driving member 250 and the first locking member 240, the first locking member 240 is driven to move to the first locked position under the restoring force of the first elastic member 260, thereby maintaining relative fixation between the first connecting seat 210 and the second connecting seat 220.

[0193] It should also be noted that in the cart 1000 using the joint structure 200 shown in the eighth embodiment, the rider frame 110 is connected to the first connecting seat 210, the front wheel frame 120 is connected to the second connecting seat 120, the rear wheel frame 130 is connected to the rotating seat 330, and the seat 170 is pivotally connected to both the front wheel frame 120 and the rear wheel frame 130. When the rear wheel frame 130 moves closer to the front wheel frame 120, the seat 170 is driven to pivot simultaneously relative to the front wheel frame 120 and the rear wheel frame 130 to be folded.

[0194] Referring to FIG. 33 , the ninth embodiment of the present invention provides a joint structure 200. This joint structure 200 can be considered a variation of the joint structure 200 of the eighth embodiment described above, differing primarily in the repositioning of the second elastic member 320. In this embodiment, the second elastic member 320 is positioned between the second locking member 280 and the second connecting seat 220. Therefore, unless otherwise specified, the operating principles of the various components of this joint structure 200 can be found in the corresponding operating principles of the joint structure 200 of the eighth embodiment described above and will not be further elaborated here.

[0195] Referring to FIG34 , the tenth embodiment of the present invention provides a joint structure 200. This joint structure 200 can also be considered a variation of the joint structure 200 of the first embodiment. The main difference is that the driving member 250 is located between the first locking member 240 and the second connecting seat 220, the second locking member 280 is located between the driving member 250 and the second connecting seat 220, and the locking portion 281 of the second locking member 280 protrudes toward the second connecting seat 220 in a direction parallel to the axial direction. In addition, a fifth elastic member 340 is provided between the second connecting seat 220 and the second locking member 280. The fifth elastic member 340 is used to provide an elastic restoring force for the second locking member 280 to maintain the second locking member 280 in the first unlocked position. The first elastic member 260 abuts between the first locking member 240 and the first connecting seat 210. Unless otherwise specified, the working principles of the various components of this joint structure 200 can be referred to the working principles of the corresponding components of the joint structure 200 of the first embodiment above, and will not be repeated here. The following mainly describes the differences between this embodiment and the first embodiment.

[0196] Specifically, in this embodiment, when the driving member 250 is in the initial position, the driving member 250 is located in the second connecting seat 220, the first locking member 240 is in the first locking position, and the first locking member 240 is engaged with the first connecting seat 210 and the second connecting seat 220 at the same time; the second locking member 280 is in the second locking position, the locking portion 281 passes through the second connecting seat 220 and the third connecting seat 230 in sequence and abuts against the third locking member 310, so that the third locking member 310 is in the third locking position, even if the third locking member 310 is engaged with the third connecting seat 230 and the fourth connecting seat 290 at the same time.

[0197] When the driving member 250 moves from the initial position to the unlocked position, the driving member 250 drives the first locking member 240 to move in the reverse axial direction, causing the first locking member 240 to move into the first connecting seat 210 and reach the first unlocked position. During this reverse axial movement, the driving member 250 gradually stops contacting the second locking member 280. Under the reset action of the fifth elastic member 340, the second locking member 280 is driven to move to the second unlocked position, away from the third connecting seat 230. When the locking portion 281 of the second locking member 280 moves in a direction parallel to the reverse axial direction, the third locking member 310 is no longer contacted by the locking portion 281. Under the action of the second elastic member 320, the third locking member 310 is moved to the third unlocked position. It should be noted that, in this embodiment, the first release position of the first locking member 240 is located in the first connecting seat 210, the third release position of the third locking member 310 is located in the third connecting seat 230, and the first traction member 270 is passed through the second connecting seat 220 and is arranged in the front wheel frame 120.

[0198] When the driving member 250 moves from the unlocked position to the initial position, the driving member 250 pushes the second locking member 280 to move along the positive axial direction to the second locked position. The locking portion 281 passes through the second connecting seat 220 and the third connecting seat 230 and abuts against the third locking member 310, thereby maintaining relative fixation between the fourth connecting seat 290 and the third connecting seat 230, and between the third connecting seat 230 and the second connecting seat 220. In addition, after the driving member 250 moves to the initial position, the first locking member 240 is no longer pressed by the driving member 250. Due to the movable gap between the driving member 250 and the first locking member 240, the first locking member 240 is driven to move to the first locked position under the restoring force of the first elastic member 260, thereby maintaining relative fixation between the first connecting seat 210 and the second connecting seat 220.

[0199] 35 to 41 , the eleventh embodiment of the present application provides a joint structure 200 , which can also be regarded as a variation of the joint structure 200 in the first embodiment, with the following differences:

[0200] The first connecting seat 210 is provided with a first pushing portion 216 . The first pushing portion 216 is spaced apart from the first limiting column 211 along the circumferential direction. The first pushing portion 216 can be elastically deformed along the radial direction.

[0201] Referring to Figure 38, when the cart 1000 is in a folded state, in the circumferential direction, the first pushing portion 216 is located between the first limiting column 211 and the third limiting column 231, and the third limiting column 231 is located between the first pushing portion 216 and the second limiting column 221. The first pushing portion 216 is used to push the third limiting column 231 toward the second limiting column 221.

[0202] Referring to Figure 40 , when the cart 1000 is in the extended state, the third limiting post 231 is circumferentially located between the first limiting post 211 and the first abutting portion 216. That is, the first abutting portion 216 and the first limiting post 211 are circumferentially located on either side of the third limiting post 231, and the first abutting portion 216 and the third limiting post 231 are circumferentially spaced apart. It can be seen that the third limiting post 231 is located both between the first limiting post 211 and the first abutting portion 216 and between the first limiting post 211 and the second limiting post 221. As shown in Figure 40 , when the cart 1000 is in the extended state, a portion of the first abutting portion 216 is also located opposite the second limiting post 221 in a direction parallel to the axial direction.

[0203] Referring to Figures 38 and 40 , during the transition of the stroller 1000 from the folded state to the extended state, the first abutting portion 216 abuts the third limiting post 231 in the circumferential direction opposite to the first limiting post 211, pushing the third limiting post 231 to slide toward the wall of the movable slot 224 on the side closer to the second limiting post 221. This allows the rear wheel frame 130 to rotate circumferentially away from the front wheel frame 120 shortly after the handrail 110 rotates. When the third limiting post 231 abuts the wall of the movable slot 224 on the side closer to the second limiting post 221, the angle between the rear wheel frame 130 and the front wheel frame 120 forms a first angle α1. At this point, the rear wheel frame 130, the front wheel frame 120, and the supporting surface (e.g., the ground) form a triangular stable structure, and the third limiting post 231 can no longer move relative to the second limiting post 221. However, the first abutting portion 216 can continue to move in the opposite circumferential direction relative to the third limiting post 231. During this period, due to the obstruction of the third limiting post 231, the first abutting portion 216 undergoes elastic deformation in the radial direction and is able to move in the opposite circumferential direction to the radially outer side of the third limiting post 231. Then, the first abutting portion 216 continues to move until it passes over the third limiting post 231 and reaches the side of the third limiting post 231 circumferentially away from the first limiting post 211. At this point, the first abutting portion 216 radially returns to its shape before contact with the third limiting post 231. During this process, the first limiting post 211 moves in the opposite circumferential direction toward the third limiting post 231 until it contacts the third limiting post 231. At this point, the cart 1000 completes the transition and is in the extended state.

[0204] It can be seen that this embodiment does not need to use the first limiting column 211 to push the third limiting column 231 to slide toward the groove wall of the movable groove 224 close to the second limiting column 221 side as in the first embodiment, thereby realizing the relative opening of the rear wheel frame 130 and the front wheel frame 120. This embodiment accelerates the deployment speed of the cart 1000 and improves the switching rate.

[0205] 36 , 38 , and 40 , the first abutting portion 216 is configured as an elastic arm extending in a direction intersecting the circumferential direction. Specifically, the ridges 217 of this embodiment are discontinuously arranged along the circumference, as compared to the first embodiment. That is, the ridges 217 are intermittently distributed along the circumference. A notch is formed in the ridges 217. The first abutting portion 216 is located in the notch, with one end of the first abutting portion 216 connected to one circumferential edge of the notch. The other end of the first abutting portion 216 is disconnected from the other circumferential edge of the notch and extends inward toward the area enclosed by the ridges 217 to abut the third limiting post 231. When the cart 1000 is transitioning from the folded state to the extended state, the first abutting portion 216 can deform radially toward the corresponding notch to move radially outward of the third limiting post 231.

[0206] 38 and 39 , a side of the third limiting post 231 proximate to the first limiting post 211 is provided with an abutting surface 2311. This abutting surface 2311 is located on the path of the first abutting portion 216 moving in the opposite circumferential direction. This allows the first abutting portion 216 to effectively abut the side of the third limiting post 231 proximate to the first limiting post 211 when the third limiting post 231 moves in the opposite circumferential direction, thereby pushing the third limiting post 231 in the opposite circumferential direction. When the first abutting portion 216 abuts against the abutting surface 2311, the angle between the extending direction of the abutting surface 2311 and the extending direction of the first abutting portion 216 is between 65° and 75°. This prevents the first abutting portion 216 from moving radially outward of the third limiting post 231 when pushing the third limiting post 231 in the opposite circumferential direction.

[0207] In a direction parallel to the axial direction, the second limiting post 221 is located on one side of the circumferential movement trajectory of the first resisting portion 216. This ensures that the first resisting portion 216 does not abut against the second limiting post 221 when moving in the circumferential direction, and can pivot at any angle relative to the second limiting post 221. Referring to FIG40 , when the cart 1000 is in the extended state, the first resisting portion 216 can also be completely offset from the second limiting post 221 in a direction parallel to the axial direction, that is, the first resisting portion 216 can be completely located on the side of the second limiting post 221 away from the third limiting post 231, rather than as shown in FIG40 , where a portion of the first resisting portion 216 is also disposed opposite the second limiting post 221 in a direction parallel to the axial direction. Specifically, the first abutting portion 216 protrudes from the bottom wall of the first accommodating space 212 within the first connecting seat 210 toward the second connecting seat 220 in a direction parallel to the axial direction. The extension length of the first abutting portion 216 in the direction parallel to the axial direction, that is, the extension length of the first abutting portion 216 toward the second connecting seat 220, is less than or equal to the distance between the second limiting post 221 and the first connecting seat 210 in a direction parallel to the axial direction. It can be understood that the plane where the end surface of the first abutting portion 216 facing the second connecting seat 220 lies is spaced apart from or flush with the plane where the end surface of the second limiting post 221 facing the first connecting seat 210 lies in a direction parallel to the axial direction. Consequently, when the cart 1000 switches from the folded state to the extended state, the second limiting post 221 does not hinder the circumferential rotation of the first abutting portion 216.

[0208] 35 and 36 , in the joint structure 200 provided in this embodiment, the first connecting seat 210 is not provided with the first engaging member 215, and the second connecting seat 220 is not provided with the second engaging member 225. However, in other embodiments, the first connecting seat 210 of the eleventh embodiment may also be provided with the first engaging member 215, and the second connecting seat 220 may also be provided with the second engaging member 225.

[0209] 35, 36, and 38, the first connection seat 210 is further provided with a fourth limiting post 218. The fourth limiting post 218 extends toward the second connection seat 220 in a direction parallel to the axial direction and is circumferentially spaced apart from the first limiting post 211. In a direction parallel to the axial direction, the second limiting post 221 is located on one side of the circumferential movement trajectory of the fourth limiting post 218. This prevents the fourth limiting post 218 from circumferentially abutting against the second limiting post 221 and allows the fourth limiting post 218 to pivot at any angle relative to the second limiting post 221. In this embodiment, the first limiting post 211 and the fourth limiting post 218 are radially opposed.

[0210] It should be noted that the fourth limiting post 218 extends toward the second connecting seat 220 and is spaced apart from the axial direction. Preferably, the fourth limiting post 218 extends in a direction parallel to the axial direction. Specifically, the fourth limiting post 218 is also formed to protrude from the bottom wall of the first accommodating space 212 in the first connecting seat 210 toward the second connecting seat 220.

[0211] Specifically, the length of the fourth limiting post 218 extending in a direction parallel to the axial direction, that is, the length of the fourth limiting post 218 extending toward the second connecting seat 220, must be less than or equal to the distance between the second limiting post 221 and the first connecting seat 210 in a direction parallel to the axial direction. This means that the plane where the end surface of the fourth limiting post 218 facing the second connecting seat 220 lies is spaced apart from or flush with the plane where the end surface of the second limiting post 221 facing the first connecting seat 210 lies, parallel to the axial direction. Consequently, when the cart 1000 switches between the folded and extended positions, the second limiting post 221 does not hinder the circumferential rotation of the fourth limiting post 218.

[0212] Referring to Figure 40, when the cart 1000 is in the extended state, the third limiting post 231 is located between the first limiting post 211 and the fourth limiting post 218 in the circumferential direction, and the third limiting post 231 is also located between the first limiting post 211 and the second limiting post 221 in the circumferential direction. The fourth limiting post 218 is used to push the third limiting post 231 along the positive direction of the circumference to move the third limiting post 231 away from the second limiting post 221. In the illustrated embodiment, the fourth limiting column 218 is arranged farther away from the third limiting column 231 than the second limiting column 221, and the fourth limiting column 218 is completely offset from the second limiting column 221 in a direction parallel to the axial direction, that is, in the circumferential direction, the fourth limiting column 218 and the first limiting column 211 are respectively located on both sides of the second limiting column 221. Therefore, when the fourth limiting column 218 moves along the positive direction of the circumferential direction, it needs to first pass over the second limiting column 221 before it can push the third limiting column 231 in a direction away from the second limiting column 221.

[0213] 38 , when the cart 1000 is in the folded state, the third limiting post 231 is still circumferentially located between the first limiting post 211 and the fourth limiting post 218, and the third limiting post 231 is still circumferentially located between the first limiting post 211 and the second limiting post 221. However, the fourth limiting post 218 is now positioned closer to the third limiting post 231 than the second limiting post 221. In the illustrated embodiment, the fourth limiting post 218 is still completely offset from the second limiting post 221 in a direction parallel to the axial direction.

[0214] 38 and 40 , when the cart 1000 switches from the extended state to the folded state, the fourth limiting post 218 moves along the positive circumferential direction toward the third limiting post 231. When the fourth limiting post 218 moves to a position opposite the second limiting post 221 in a direction parallel to the axial direction, the fourth limiting post 218 and the second limiting post 221 simultaneously abut the side of the third limiting post 231 away from the first limiting post 211 in the circumferential direction. Furthermore, when the fourth limiting post 218 continues to move along the positive circumferential direction, the fourth limiting post 218 pushes the third limiting post 231 in the positive circumferential direction to move within the movable groove 224 toward the groove wall away from the second limiting post 221 until the third limiting post 231 abuts the groove wall of the movable groove 224 away from the second limiting post 221 in the positive circumferential direction. At this time, the third limiting post 231 is clamped in the circumferential direction between the fourth limiting post 218 and the groove wall of the movable groove 224 away from the second limiting post 221. At this point, the cart 1000 completes the conversion and is in a folded state.

[0215] In this embodiment, no matter the cart 1000 is in the extended state or the folded state, the third limiting post 231 is located between the first limiting post 211 and the fourth limiting post 218 in the circumferential direction.

[0216] Compared to the first embodiment, in addition to the driver frame 110 pushing the rear wheel frame 130 to move closer to the front wheel frame 120, the illustrated embodiment allows the third limiting post 231 to move toward the groove wall of the movable groove 224 away from the second limiting post 221. In addition, the fourth limiting post 218 pushes the third limiting post 231, allowing the third limiting post 231 to move toward the groove wall of the movable groove 224 away from the second limiting post 221.

[0217] 36, 38 and 40, the first push portion 216 is also circumferentially located between the first limiting post 211 and the fourth limiting post 218. Furthermore, the circumferential distance between the first push portion 216 and the fourth limiting post 218 is greater than or equal to the maximum circumferential width of the third limiting post 231.

[0218] When the cart 1000 is in the extended state, referring to Figure 40, both the first push portion 216 and the third limiting column 231 are located between the first limiting column 211 and the fourth limiting column 218 in the circumferential direction, and the third limiting column 231 is located between the first limiting column 211 and the first push portion 216 in the circumferential direction, and the fourth limiting column 218 is arranged farther away from the third limiting column 231 than the first push portion 216 in the circumferential direction.

[0219] When the cart 1000 switches from the extended state to the folded state, the first abutting portion 216 moves in the positive circumferential direction and, before the fourth limiting post 218, crosses the second limiting post 221 to contact the third limiting post 231. The first abutting portion 216 undergoes elastic deformation in the radial direction and moves radially outward of the third limiting post 231. Subsequently, the first abutting portion 216 continues to move to the side of the third limiting post 231 circumferentially closer to the first limiting post 211, where it resumes its elastic deformation. Simultaneously, the fourth limiting post 218 moves in the positive circumferential direction to a position opposite the second limiting post 221 in a direction parallel to the axial direction. At this point, the fourth limiting post 218 and the first abutting portion 216 are circumferentially located on either side of the third limiting post 231. Specifically, the end of the first abutting portion 216 not connected to the ridge portion 217 and the fourth limiting post 218 are circumferentially located on either side of the third limiting post 231. That is, circumferentially, the third limiting post 231 is located between the first abutting portion 216 and the fourth limiting post 218. When the fourth limiting post 218 continues to move relative to the second limiting post 221 in the positive circumferential direction, it pushes the third limiting post 231 to move to the side of the movable groove 224 away from the second limiting post 221. At this point, the cart 1000 completes its conversion and reaches the folded state.

[0220] Referring to Figures 39 and 40, a crimping surface 2312 is provided on the side of the third limiting column 231 close to the second limiting column 221. The crimping surface 2312 is located on the trajectory of the first pushing portion 216 moving in the positive direction of the circumference, so that the first pushing portion 216 can effectively contact the crimping surface 2312 in the positive direction of the circumference, and when the first pushing portion 216 contacts the crimping surface 2312, the extension direction of the crimping surface 2312 is roughly parallel to the extension direction of the first pushing portion 216, for example, the angle between the two is between 0° and 25°, so that when the first pushing portion 216 contacts the third limiting column 231 in the positive direction of the circumference, it will not generate excessive resistance, and can smoothly move along the positive direction of the circumference to the radial outside of the third limiting column 231.

[0221] Since the second limiting post 221 is located on one side of the circumferential movement trajectory of the fourth limiting post 218 in the direction parallel to the axial direction, and is also located on one side of the circumferential movement trajectory of the first pushing portion 216, when the cart 1000 is switched from the folded state to the extended state, the fourth limiting post 218 and the first pushing portion 216 can both pass over the second limiting post 221 when moving in the opposite direction of the circumference, so that the third limiting post 231 can abut against the second limiting post 221 in the opposite direction of the circumference. The limiting column 231 can smoothly stop at the second limiting column 221 under the push of the first pushing portion 216 in the opposite direction of the circumferential direction, and will not stop moving prematurely due to the abutment between the fourth limiting column 218 and the second limiting column 221 in the opposite direction of the circumferential direction. At the same time, the first limiting column 211 can also move smoothly in the opposite direction of the circumferential direction until it stops at the third limiting column 231, and will not stop moving prematurely due to the abutment between the first pushing portion 216 and the second limiting column 221 in the opposite direction of the circumferential direction.

[0222] Referring to Figures 35 and 41 , the stroller 1000 is further provided with a third pulling member 180. One end of the third pulling member 180 is connected to the first handle frame 111, and the other end is connected to the seat 170. Preferably, the third pulling member 180 is a fabric belt. When the first handle frame 111 is deployed relative to the second handle frame 112, the seat 170 rotates clockwise under the pull of the third pulling member 180, that is, pivots circumferentially toward the side away from the rear wheel frame 130.

[0223] 35, 37, and 41, the fourth connecting seat 290 in this embodiment is additionally provided with a second push portion 294. The second push portion 294 is disposed on the side of the fourth connecting seat 290 facing the third connecting seat 230. The second push portion 294 is columnar and extends parallel to the axial direction into the third connecting seat 230. The second connecting seat 220 is also additionally provided with a third push portion 227. The third push portion 227 is disposed on the side of the second connecting seat 220 facing away from the first connecting seat 210 and extends parallel to the axial direction into the third connecting seat 230. The second push portion 294 and the third push portion 227 are circumferentially opposed to each other, and the third push portion 227 is located in front of the second push portion 294 along the direction in which the seat 170 pivots away from the rear wheel frame 130. The third connecting seat 230 is provided with a limiting groove 236 for accommodating the second pushing portion 294 and the third pushing portion 227. The limiting groove 236 passes through the third connecting seat 230 in a direction parallel to the axial direction and extends circumferentially. The limiting groove 236 allows the second pushing portion 294 and the third pushing portion 227 to move circumferentially.

[0224] It should be noted that the second abutting portion 294 extends toward the third connecting seat 230 and is spaced axially therefrom; specifically, the second abutting portion 294 protrudes from the bottom wall of the fourth accommodating space 291 within the fourth connecting seat 290 toward the third connecting seat 230. The third abutting portion 227 faces the third connecting seat 230 and is spaced axially therefrom; specifically, the third abutting portion 227 protrudes from the surface of the second connecting seat 220 facing the third connecting seat 230 toward the third connecting seat 230. Preferably, the second abutting portion 294 and the third abutting portion 227 extend parallel to the axial direction.

[0225] When the seat 170 pivots circumferentially away from the rear wheel frame 130, the second abutting portion 294 of the seat 170 pushes the third abutting portion 227 to rotate in the same direction. Subsequently, the front wheel frame 120 also pivots circumferentially away from the rear wheel frame 130 to complete the unfolding action of the stroller 1000 faster.

[0226] When the third abutting portion 227 moves along the direction in which the seat 170 moves away from the rear wheel frame 130 until it abuts the end of the limiting groove 236 circumferentially closest to the third abutting portion 227, the angle between the front wheel frame 120 and the rear wheel frame 130 is exactly the first angle α1. Furthermore, when the second abutting portion 294 moves along the direction in which the seat 170 moves toward the rear wheel frame 130 and abuts the end of the limiting groove 236 circumferentially closest to the second abutting portion 294, the angle between the seat 170 and the rear wheel frame 130 is exactly the angle between the seat 170 and the rear wheel frame 130 when the stroller 1000 is in the folded state. In other words, the circumferential ends of the limiting groove 236 respectively limit the rotational travel of the second abutting portion 294 and the third abutting portion 227.

[0227] The process of switching the stroller 1000 from the folded state to the extended state includes a first stage and a second stage. In the first stage, the handle frame 110 rotates circumferentially away from the front wheel frame 120, and the handle frame 110 drives the rear wheel frame 130 to rotate circumferentially away from the front wheel frame 120. In the second stage, the first handle frame 111 unfolds relative to the second handle frame 112. The first handle frame 111 drives the seat 170 to rotate circumferentially away from the rear wheel frame 130 via the third pulling member 180, and the seat 170 drives the front wheel frame 120 to rotate circumferentially away from the rear wheel frame 130.

[0228] 35, 37, and 41, a guide portion 237 is provided on a side of the third connecting seat 230 facing the fourth connecting seat 290. The guide portion 237 extends circumferentially around the axial direction and protrudes toward the fourth connecting seat 290 in a direction parallel to the axial direction. Specifically, the guide portion 237 protrudes from the bottom wall of the third accommodating space 232 within the third connecting seat 230 toward the fourth connecting seat 290. The second locking member 280 and the third locking member 310 are both sleeved radially outwardly of the guide portion 237. The guide portion 237 is used to guide the second locking member 280 and the third locking member 310 for axial movement. The guide portion 237 is provided with a plurality of guide grooves 238 , which are recessed axially from the circumferential surface of the guide portion 237 and spaced apart along the circumference. The guide grooves 238 are configured to receive the plurality of engaging portions 283 in a one-to-one correspondence along a direction parallel to the axial direction, thereby guiding the corresponding engaging portions 283 for movement parallel to the axial direction and limiting circumferential rotation of the engaging portions 283, thereby limiting axial rotation of the second locking member 280. In other embodiments, only one engaging portion 283 and one guide groove 238 may be provided.

[0229] It should be noted that the terms "first", "second", "third", "fourth", "fifth", etc. in this application are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0230] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0231] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A joint structure, characterized in that: include: a first connecting seat, a second connecting seat, and a third connecting seat, wherein the first connecting seat, the second connecting seat, and the third connecting seat are pivotally connected to each other around an axial direction, the second connecting seat is located between the first connecting seat and the third connecting seat along the axial direction, and the first connecting seat is provided with a first limiting column, the second connecting seat is provided with a second limiting column, and the third connecting seat is provided with a third limiting column, and the first limiting column, the third limiting column, and the second limiting column are arranged in sequence along the circumferential direction; and The first locking member is movably arranged between the first connecting seat and the second connecting seat, and has a first locking position and a first releasing position, and is located on a radial side of the first limiting column, the second limiting column and the third limiting column. When the first locking member is in the first locking position, the first connecting seat, the second connecting seat and the third connecting seat are relatively fixed, and the third limiting column is in contact with at least one of the first limiting column and the second limiting column; when the first locking member is in the first releasing position, the first connecting seat and the third connecting seat can both pivot relative to the second connecting seat.

2. The joint structure according to claim 1, characterized in that The first limiting column protrudes toward the second connecting seat, the second limiting column protrudes toward the first connecting seat, the third limiting column protrudes toward the first connecting seat and passes through the second connecting seat, and the second connecting seat is provided with a movable groove for the third limiting column to move along the circumferential direction. The first limiting column and the third limiting column can move along the circumferential direction within the second connecting seat.

3. The joint structure according to claim 1, characterized in that The first locking member is located radially outside the first limiting column, the second limiting column, and the third limiting column.

4. The joint structure according to claim 1, characterized in that The joint structure also includes a driving member, which is movably arranged between the first connecting seat and the second connecting seat and has an initial position and an unlocking position. When the driving member moves from the initial position to the unlocking position, the driving member drives the first locking member to move from the first locking position to the first releasing position. The driving member and the first locking member are adjacently arranged along the axial direction, and the driving member and the first locking member are both located radially outside the first limiting column, the second limiting column and the third limiting column.

5. The joint structure according to claim 1, characterized in that The joint structure also includes a second locking piece, which is movably arranged in the joint structure and is provided with at least one locking portion, and the locking portion is spaced apart from the axial direction. The second locking piece has a second locking position and a second release position. When the first locking piece is in the first locking position, the second locking piece is in the second locking position, and the at least one locking portion passes through the third connecting seat and the second connecting seat. When the first locking piece is in the first release position, the second locking piece is in the second release position, and the at least one locking portion only passes through the third connecting seat or the second connecting seat.

6. The joint structure according to claim 5, characterized in that When the first locking member moves from the first locking position to the first unlocking position, the first locking member drives the second locking member to move from the second locking position to the second unlocking position.

7. A cart, characterized in that: include: A rider frame, a front wheel frame, a rear wheel frame, and a joint structure according to any one of claims 1 to 6, wherein the rider frame is connected to the first connecting seat, the front wheel frame is connected to the second connecting seat, and the rear wheel frame is connected to the third connecting seat, and the rider frame, the front wheel frame, and the rear wheel frame are pivotally connected to each other via the joint structure so that the stroller can be switched between an extended state and a folded state, and the rear wheel frame is located between the front wheel frame and the rider frame along the circumferential direction; When the cart is in the extended state, the first locking member is in the first locking position, and the handlebar frame, the front wheel frame, and the rear wheel frame are spaced apart in the circumferential direction; When the pushcart is in the folded state, the hand frame is circumferentially close to the rear wheel frame, and the rear wheel frame is circumferentially close to the front wheel frame.

8. The cart according to claim 7, wherein: When the cart is in the folded state, the first limiting post, the third limiting post and the second limiting post are arranged at intervals along the circumferential direction.

9. The stroller according to claim 7, wherein: include: According to the joint structure of claim 2, when the cart is in the folded state, the third limiting column abuts against the groove wall of the movable groove on the side away from the second limiting column along the circumferential direction.

10. The cart according to claim 7, wherein: The first connecting seat is provided with a first engaging member, and the second connecting seat is provided with a second engaging member. The first engaging member and the second engaging member are both located between the first limiting post and the second limiting post along the circumferential direction, and are located on a side of the first limiting post and the second limiting post away from the third limiting post along the circumferential direction; When the cart is in the folded state, the first engaging member abuts against the second engaging member at a side of the second engaging member close to the second limiting column.

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