Trolley and joint structure thereof

Abstract

A trolley and its joint structure are disclosed. The joint structure includes a first connecting seat, a second connecting seat, and a third connecting seat that are pivotally connected to each other in sequence around an axial direction. 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. The first limiting post, the third limiting post, and the second limiting post are arranged sequentially in the circumferential direction. A first locking member is axially movably disposed between the first connecting seat and the second connecting seat, and has a first locking position and a first unlocking position. 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 the first limiting post and / or the second limiting post. When the first locking member is in the first unlocking position, the first connecting seat and the third connecting seat can pivot relative to the second connecting seat.

Description

Technical Field

[0001] This application relates to the field of wheeled mobility device technology, and in particular to a trolley and its joint structure. Prior Technology

[0002] For families with infants and toddlers, using strollers as an auxiliary care tool when out and about has become very common and convenient. Strollers mainly consist of a frame and a seat, most of which are designed to be foldable. When not in use, the stroller can be reduced in size by folding the frame and seat, making it easier to store or carry. However, while the folding design brings convenience, traditional folding joint structures are often quite complex, resulting in a larger size that not only takes up a lot of space but also makes the stroller look bulky and affects its aesthetics. Summary of the Invention

[0003] Therefore, it is necessary to provide a trolley and its joint structure to address the above problems.

[0004] A joint structure includes: a first connecting seat, a second connecting seat, and a third connecting seat, the first connecting seat, the second connecting seat, and the third connecting seat being pivotally connected to each other about an axial direction, the second connecting seat being located between the first connecting seat and the third connecting seat along the axial direction, and the first connecting seat having a first limiting post, the second connecting seat having a second limiting post, and the third connecting seat having a third limiting post, the first limiting post, the third limiting post, and the second limiting post being arranged sequentially in a circumferential direction; a first locking member being movably disposed between the first connecting seat and the second connecting seat, having a first locking position and a first unlocking position, and being located on a 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 unlocking position, both the first connecting seat and the third connecting seat can pivot relative to the second connecting seat.

[0005] In one embodiment, the first limiting post protrudes toward the second connecting seat, the second limiting post protrudes toward the first connecting seat, and the third limiting post protrudes toward the first connecting seat and passes through the second connecting seat. The second connecting seat is provided with a movable groove for the third limiting post to move along the circumferential direction. The first limiting post and the third limiting post are capable of moving along the circumferential direction within the second connecting seat.

[0006] In one embodiment, the first locking member is located radially outside the first limiting post, the second limiting post, and the third limiting post.

[0007] In one embodiment, the joint structure further includes a drive member movably disposed between the first connecting seat and the second connecting seat, and having an initial position and an unlocked position. When the drive member moves from the initial position to the unlocked position, the drive member drives the first locking member to move from the first locking position to the first unlocking position. The drive member and the first locking member are arranged adjacent to each other along the axial direction, and the drive member and the first locking member are both located radially outside the first limiting post, the second limiting post, and the third limiting post.

[0008] In one embodiment, the drive member is located between the first connecting seat and the first locking member and is disposed adjacent to the first locking member. The drive member is used to drive the first locking member to move to the second connecting seat to the first unlocking position.

[0009] In one embodiment, the first connector, the second connector, and the third connector are pivotally connected to each other via a first pivot, the first pivot restricting the first connector, the second connector, and the third connector from axially separating.

[0010] In one embodiment, when the first locking member is in the first locked position, the first locking member engages with both the first connecting seat and the second connecting seat; when the first locking member is in the first unlocked position, the first locking member engages with the second connecting seat and disengages from the first connecting seat, so that the first connecting seat can pivot relative to the second connecting seat.

[0011] In one embodiment, a first elastic member is provided between the first locking member and the second connecting seat, the first elastic member providing elastic restoring force to keep the first locking member in the first locked position.

[0012] In one embodiment, the joint structure further includes a second locking member, movably disposed in the joint structure and having 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 unlocking 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 passing through the third connecting seat and the second connecting seat, when the first locking member is in the first unlocking position, the second locking member is in the second unlocking position, the at least one locking portion passing through only the third connecting seat or the second connecting seat.

[0013] 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.

[0014] In one embodiment, when the first locking member moves to the second connecting seat, the first locking member drives the at least one locking part to move away from the second connecting seat, so that the at least one locking part passes only through the third connecting seat to the second unlocking position.

[0015] A trolley includes: a handlebar frame, a front wheel frame, a rear wheel frame, and the aforementioned joint structure. The handlebar frame is connected to a first connecting seat, the front wheel frame is connected to a second connecting seat, and the rear wheel frame is connected to a third connecting seat. The handlebar frame, the front wheel frame, and the rear wheel frame are pivotally connected to each other via the joint structure, allowing the trolley to switch between an extended state and a folded state. The rear wheel frame is circumferentially located between the front wheel frame and the handlebar frame. When the trolley is in the extended state, a first locking member is in a first locking position, and the handlebar frame, the front wheel frame, and the rear wheel frame are circumferentially spaced apart. When the trolley is in the folded state, the handlebar frame is circumferentially close to the rear wheel frame, and the rear wheel frame is circumferentially close to the front wheel frame.

[0016] In one embodiment, when the trolley is in the folded state, the first locking member is in the first unlocked position.

[0017] In one embodiment, when the trolley is in the folded state, the first limiting post, the third limiting post, and the second limiting post are spaced apart circumferentially.

[0018] In one embodiment, when the trolley is in the folded state, the third limiting post abuts circumferentially against the groove wall on the side of the movable groove away from the second limiting post.

[0019] 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 post and the second limiting post along the circumferential direction, and are located on the side of the first limiting post and the second limiting post that is circumferentially away from the third limiting post. When the trolley is in the folded state, the first engaging member abuts against the second engaging member on the side of the second engaging member that is close to the second limiting post.

[0020] In one embodiment, when the trolley is in the extended state, the first engaging member is located on the side of the second engaging member close to the first limiting post, and is spaced apart from the second engaging member.

[0021] In one embodiment, the first engaging member includes an elastic arm and a protrusion, the elastic arm having an elastic force that deforms radially, and the protrusion being located radially inside the elastic arm; when the trolley is in the folded state, the elastic arm is at least partially located radially outside the second engaging member, and the protrusion abuts against the second engaging member on the side of the second engaging member near the second limiting post.

[0022] In one embodiment, at least one of the first engaging member and the second engaging member is provided with a guide slope. When the first connecting seat rotates circumferentially relative to the second connecting seat, the guide slope is used to guide the first engaging member to move from the side of the second engaging member near the first limiting post to the side of the second engaging member near the second limiting post.

[0023] In one embodiment, the outer side of the second connecting seat is provided with a first blocking part, and the outer side of the third connecting seat is provided with a second blocking part. When the first locking member is in the first unlocking position and the trolley is not in the folded state, the first blocking part and the second blocking part abut against each other in the circumferential direction.

[0024] In one embodiment, the first blocking portion is disposed on the outer periphery of the second connecting seat, the first blocking portion extends toward the third connecting seat and protrudes outward relative to the outer periphery of the second connecting seat; the second blocking portion is disposed on the outer periphery of the third connecting seat, the second blocking portion extends toward the second connecting seat and protrudes outward relative to the outer periphery of the third connecting seat.

[0025] In one embodiment, the first connecting seat is provided with a first pushing part, which protrudes towards the second connecting seat. The first pushing part is spaced apart from the first limiting post in the circumferential direction. When the trolley is in the folded state, the first pushing part is located between the first limiting post and the third limiting post in the circumferential direction. The third limiting post is located between the first pushing part and the second limiting post in the circumferential direction. When the trolley switches from the folded state to the extended state, the first pushing part pushes against the third limiting post in the direction closer to the second limiting post.

[0026] In one embodiment, when the trolley is in the folded state, the first pushing part is located between the first limiting post and the third limiting post in the circumferential direction; when the trolley is in the extended state, the third limiting post is located between the first limiting post and the first pushing part in the circumferential direction; and the first pushing part can elastically deform in the radial direction.

[0027] In one embodiment, the second limiting post is located on one side of the trajectory along which the first pushing part moves circumferentially in a direction parallel to the axial direction.

[0028] In one embodiment, the plane of the first pushing part facing the end face of the second connecting seat and the plane of the second limiting post facing the end face of the first connecting seat are spaced apart or flush in a direction parallel to the axial direction.

[0029] In one embodiment, the first pushing portion is provided as an elastic arm, the extension direction of which intersects the circumferential direction.

[0030] In one embodiment, the third limiting post has an abutting surface on the side near the first limiting post. The abutting surface is located on the trajectory of the first pushing part moving circumferentially. When the first pushing part abuts against the abutting surface, the angle between the extending direction of the abutting surface and the extending direction of the first pushing part is between 65° and 75°.

[0031] In one embodiment, the first connecting seat is further provided with a fourth limiting post, which protrudes toward the second connecting seat and is spaced apart from the first limiting post in the circumferential direction. When the trolley is in the extended state, the third limiting post is located between the first limiting post and the fourth limiting post in the circumferential direction. When the trolley switches from the extended state to the folded state, the fourth limiting post pushes against the third limiting post to move the third limiting post away from the second limiting post.

[0032] In one embodiment, when the trolley is in the extended state, the fourth limiting post is positioned further away from the third limiting post than the second limiting post, and the fourth limiting post is used to pass over the second limiting post in the circumferential direction to push the third limiting post to move away from the second limiting post.

[0033] In one embodiment, the second limiting post is located on one side of the trajectory along which the fourth limiting post moves circumferentially in a direction parallel to the axial direction.

[0034] In one embodiment, the plane on which the fourth limiting post faces the end face of the second connecting seat is located is spaced apart from or exactly flush with the plane on which the second limiting post faces the end face of the first connecting seat in a direction parallel to the axial direction.

[0035] In one embodiment, the first pushing part is located circumferentially between the first limiting post and the fourth limiting post.

[0036] In one embodiment, the circumferential distance between the first pushing part and the fourth limiting post is greater than or equal to the maximum circumferential width of the third limiting post.

[0037] In one embodiment, when the trolley is in the extended state, the third limiting post is located circumferentially between the first limiting post and the first pushing part, and the fourth limiting post is disposed circumferentially away from the third limiting post relative to the first pushing part.

[0038] In one embodiment, the third limiting post has a pressing surface on the side near the second limiting post. The pressing surface is located on the trajectory of the first pushing part moving circumferentially. When the first pushing part contacts the pressing surface, the angle between the extending direction of the pressing surface and the extending direction of the first pushing part is between 0° and 25°.

[0039] In one embodiment, the trolley further includes a seat and a fourth connecting seat, the fourth connecting seat being pivotally connected to the third connecting seat about the axial direction, the second connecting seat and the third connecting seat being located between the first connecting seat and the fourth connecting seat, and the seat being connected to the fourth connecting seat.

[0040] In one embodiment, the trolley frame includes a first pusher frame, a second pusher frame, and a folding joint. The second pusher frame is pivotally connected to the first pusher frame via the folding joint, so that the first pusher frame can be extended or folded relative to the second pusher frame. The trolley also includes a third traction member, which is connected to the first pusher frame and the seat. When the first pusher frame is extended relative to the second pusher frame, the first pusher frame drives the seat to rotate circumferentially away from the rear wheel frame via the third traction member.

[0041] In one embodiment, the fourth connecting seat is provided with a second pushing part, and the second connecting seat is provided with a third pushing part. The second pushing part and the third pushing part are arranged opposite each other in the circumferential direction. When the first pusher frame drives the seat to rotate in the circumferential direction away from the rear wheel frame through the third traction member, the second pushing part abuts against the third pushing part to drive the front wheel frame to rotate in the circumferential direction away from the rear wheel frame.

[0042] In one embodiment, the third connecting seat is provided with a limiting groove, at least a portion of the second pushing part and at least a portion of the third pushing part protrude into the limiting groove, and the second pushing part and the third pushing part move circumferentially in the limiting groove.

[0043] In one embodiment, one end of the limiting groove in the circumferential direction is used to abut against the second pushing part, and the other end of the limiting groove in the circumferential direction is used to abut against the third pushing part.

[0044] In one embodiment, the process of switching the trolley from the folded state to the extended state includes a first stage and a second stage; in the first stage, the handlebars rotate circumferentially away from the front wheel frame, and the handlebars drive the rear wheel frame to rotate circumferentially away from the front wheel frame; in the second stage, the first pusher frame unfolds relative to the second pusher frame, and the first pusher frame drives the seat to rotate circumferentially away from the rear wheel frame via the third traction member, and the seat drives the front wheel frame to rotate circumferentially away from the rear wheel frame.

[0045] A joint structure includes: a first connecting seat, a second connecting seat, and a third connecting seat, the first connecting seat, the second connecting seat, and the third connecting seat being pivotally connected to each other about an axial direction, and the second connecting seat being located between the first connecting seat and the third connecting seat along the axial direction; a first locking member, movably disposed between the first connecting seat and the second connecting seat, having a first locking position and a first unlocking position, wherein when the first locking member is in the first locking position, the first connecting seat and the second connecting seat are relatively fixed, and when the first locking member is in the first unlocking position, the first connecting seat can pivot relative to the second connecting seat; and a second locking member, movably disposed in the joint structure and having 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 unlocking position, wherein when the second ... the second locking member being pivotally disposed between the first connecting seat and the second connecting seat. When the locking member is in the second locked position, the at least one locking part passes through the third connecting seat and the second connecting seat to fix the second connecting seat and the third connecting seat relatively. When the second locking member is in the second unlocked position, the at least one locking part passes through only the third connecting seat or the second connecting seat to pivot the second connecting seat relative to the third connecting seat. A driving member is movably disposed between the first connecting seat and the second connecting seat and has an initial position and an unlocked position. The driving member is disposed adjacent to the first locking member and / or the second locking member. When the driving member moves from the initial position to the unlocked position, the driving member drives the first locking member to move from the first locked position to the first unlocked position and drives the second locking member to move from the second locked position to the second unlocked position.

[0046] In one embodiment, when the driving member moves from the initial position to the unlocked position, the driving member directly drives the first locking member to move from the first locked position to the first unlocked position; when the first locking member moves from the first locked position to the first unlocked position, the first locking member drives the second locking member to move from the second locked position to the second unlocked position.

[0047] In one embodiment, the drive member is axially located between the first connecting seat and the first locking member and is disposed adjacent to the first locking member. The drive member is used to drive the first locking member to move to the second connecting seat to the first unlocking position. When the first locking member moves to the second connecting seat, the first locking member drives the at least one locking part to move to disengage from the second connecting seat, so that the at least one locking part passes only through the third connecting seat to move the second locking member to the second unlocking position.

[0048] In one embodiment, the joint structure further includes: a fourth connecting seat, pivotally connected to the third connecting seat about an axial direction, wherein 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, movably disposed between the third connecting seat and the fourth connecting seat, having a third locking position and a third unlocking 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 unlocking 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 unlocking position.

[0049] 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.

[0050] In one embodiment, when the at least one locking part moves to disengage from the second connecting seat, the at least one locking part drives the third locking member to move to the fourth connecting seat to the third unlocking position.

[0051] In one embodiment, when the third locking member is in the third locking position, the third locking member is engaged with both the third connecting seat and the fourth connecting seat; when the third locking member is in the third unlocking 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.

[0052] In one embodiment, a second elastic member is provided between the third locking member and the fourth connecting seat. The second elastic member provides elastic restoring force to the third locking member so that the third locking member is held in the third locking position.

[0053] In one embodiment, the second locking member has a main body portion, and the at least one locking portion protrudes 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 disposed adjacent to the third locking member.

[0054] In one embodiment, the second locking member is provided with a plurality of locking portions, which are spaced apart circumferentially.

[0055] A trolley includes: a handlebar frame, a front wheel frame, a rear wheel frame, and the aforementioned joint structure. The handlebar frame is connected to a first connecting seat, the front wheel frame is connected to a second connecting seat, and the rear wheel frame is connected to a third connecting seat. The handlebar frame, the front wheel frame, and the rear wheel frame are pivotally connected to each other via the joint structure, allowing the trolley to switch between an extended state and a folded state. The rear wheel frame is located circumferentially between the front wheel frame and the handlebar frame. When the trolley is in the extended state, the drive member is in the initial position, the first locking member is in the first locked position, and the second locking member is in the second locked position. The handlebar frame, the front wheel frame, and the rear wheel frame are spaced apart circumferentially. When the trolley is in the folded state, the handlebar frame is circumferentially close to the rear wheel frame, and the rear wheel frame is circumferentially close to the front wheel frame.

[0056] In one embodiment, when the trolley is in the folded state, the drive 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.

[0057] In one embodiment, the outer side of the second connecting seat is provided with a first blocking part, and the outer side of the third connecting seat is provided with a second blocking part. When 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 trolley is not in the folded state, the first blocking part and the second blocking part abut against each other in the circumferential direction.

[0058] In one embodiment, the handframe includes a first pusher, a second pusher, and a retraction joint. The second pusher is pivotally connected to the first pusher via the retraction joint, allowing the first pusher to be extended or retracted relative to the second pusher. The retraction joint includes: a fifth connecting seat connected to the first pusher; and a sixth connecting seat connected to the second pusher. The sixth connecting seat and the fifth connecting seat are pivotally connected to each other, allowing the first pusher to be extended or retracted relative to the second pusher. One of the fifth connecting seat and the sixth connecting seat has a limiting recess, and the other has a fifth locking member. The fifth locking member is movably disposed in 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 pusher and the second pusher remain retracted relative to each other. When the fifth locking member is in the second position, the fifth locking member retracts from the limiting recess, allowing the first pusher to pivot relative to the second pusher.

[0059] In one embodiment, at least one of the fifth locking member and the limiting recess is provided with a sliding ramp suitable for releasing the limiting.

[0060] In one embodiment, the retractable joint further includes a limiting cover and a third elastic member. The fifth connecting seat is provided with a movable hole, and the fifth locking member is movably inserted into the movable hole. The limiting cover is located on the side of the fifth connecting seat facing away from the sixth connecting seat. The third elastic member abuts between the limiting cover and the fifth locking member to keep the fifth locking member in the first position. The sixth connecting seat is provided with the limiting recess.

[0061] In one embodiment, the handframe includes a first pusher and a second pusher, the second pusher being pivotally connected to the first pusher so that the first pusher can be extended or folded relative to the second pusher. The second pusher is connected to the first connecting seat, and the drive member is connected to the first pusher via a first traction member. When the first pusher pivots relative to the second pusher, the first pusher drives the first traction member to move, thereby driving the drive member to rotate relative to the first connecting seat and move along the axial direction, so that the drive member moves from the initial position to the unlocked position.

[0062] In one embodiment, the driving member has an abutting portion that protrudes in a direction parallel to the axial direction and extends obliquely in the circumferential direction; the first connecting seat has a pushing portion that 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.

[0063] In one embodiment, the handframe includes a first pusher frame, a second pusher frame, and a retraction joint. The second pusher frame is pivotally connected to the first pusher frame via the retraction joint, allowing the first pusher frame to be extended or retracted relative to the second pusher frame. The retraction joint includes: a fifth connecting seat connected to the first pusher frame; a sixth connecting seat connected to the second pusher frame, the sixth connecting seat having a locking groove, the sixth connecting seat and the fifth connecting seat being pivotally connected to each other, allowing the first pusher frame to be extended or retracted relative to the second pusher frame; and a fourth locking member movably disposed on the first pusher frame. When the first pusher frame and the second pusher frame are extended relative to each other, the fourth locking member is inserted into the locking groove to restrict the first pusher frame from pivoting relative to the second pusher frame.

[0064] In one embodiment, the rider frame further includes a release button, which is movably disposed on the first pusher frame and connected to the fourth locking member via a second traction member. When the release button moves relative to the first pusher frame, the release button causes the fourth locking member to move relative to the first pusher frame so as to disengage from the locking groove.

[0065] In one embodiment, the handframe further includes a safety push button movably disposed on the first handframe and having a third position and a fourth position. When the safety push button is in the third position, it abuts against the release button to prevent the release button from moving relative to the first handframe. When the safety push button is in the fourth position, it is spaced apart from the release button to allow the release button to move relative to the first handframe. The direction of movement of the safety push button and the direction of movement of the release button are intersected.

[0066] A trolley includes: a handlebar, a front wheel frame, a rear wheel frame, a seat, and the aforementioned joint structure. The handlebar is connected to a first connecting seat, the front wheel frame is connected to a second connecting seat, the rear wheel frame is connected to a third connecting seat, and the seat is connected to a fourth connecting seat. The handlebar, front wheel frame, rear wheel frame, and seat are pivotally connected to each other via the joint structure, allowing the trolley to switch between an extended state and a folded state. When the trolley is in the extended state, the handlebar, rear wheel frame, front wheel frame, and seat are sequentially spaced circumferentially, the drive 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 trolley is in the folded state, the handlebar and rear wheel frame are both moved towards the front wheel frame circumferentially, and the seat is moved towards the rear wheel frame.

[0067] In one embodiment, when the trolley is in the folded state, the drive 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.

[0068] In one embodiment, the outer periphery of the third connecting seat is provided with a third blocking part, and the outer periphery of the fourth connecting seat is provided with a fourth blocking part. When the third locking member is in the third locking position, the third blocking part and the fourth blocking part abut against each other in the circumferential direction.

[0069] In one embodiment, the third blocking portion extends toward the fourth connecting seat and protrudes outward relative to the outer periphery of the third connecting seat; the fourth blocking portion extends toward the third connecting seat and protrudes outward relative to the outer periphery of the fourth connecting seat.

[0070] In one embodiment, the seat includes a seat plate, a folding back strap passing through the seat plate, and a winding mechanism connected to both ends of the folding back strap. The two ends of the folding back strap pass through the seat plate to extend from a first surface to a second surface of the seat plate and are connected to the winding mechanism disposed on the second surface. The winding mechanism automatically tightens the folding back strap. The first surface and the second surface are disposed opposite to each other. Simple Explanation of the Diagram

[0071] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Furthermore, the accompanying drawings are not drawn to a 1:1 scale, and the relative dimensions of the various components are shown as examples only and not necessarily to scale. In the accompanying drawings: Figure 1 is a perspective view of the trolley in one embodiment of this application. Figure 2 is a perspective view of the trolley from another angle in one embodiment of this application. Figure 3 is a cross-sectional view of a trolley in one embodiment of this application, wherein the trolley is in an extended state. Figure 4 is an enlarged view of circle A in Figure 3. Figure 5 is a partial perspective view of the trolley with the handrail shown in Figure 1. Figure 6 is an exploded view of the structure of the trolley with the handframe shown in Figure 1. Figure 7 is a partial perspective view of the trolley with the handframe shown in Figure 1 from another angle. Figure 8 is a cross-sectional view along line U1-U1 in Figure 7. Figure 9 is a cross-sectional view along line U2-U2 in Figure 7. Figure 10 is an enlarged view of circle B in Figure 9. Figure 11 is a cross-sectional view of the rider frame when the fifth locking member in Figure 10 extends into the limiting recess. Figure 12 is a side view of a trolley in one embodiment of this application, wherein the first pusher frame is folded relative to the second pusher frame. Figure 13 is a cross-sectional view of a trolley in one embodiment of this application, wherein the handframe is folded towards the front wheel frame and the rear wheel frame. Figure 14 is a cross-sectional view of a trolley in one embodiment of this application, wherein the trolley is in a folded state. Figure 15 is a partial three-dimensional exploded view of the trolley in one embodiment of this application, showing the joint structure in the first embodiment. Figure 16 is an enlarged view of circle C in Figure 15. Figure 17 is an enlarged view of circle D in Figure 15. Figure 18 is a partial exploded perspective view of the trolley from another angle in one embodiment of this application, showing the joint structure in the first embodiment. Figure 19 is a cross-sectional view along line U3-U3 in Figure 1. Figure 20 is a cross-sectional view along line U4-U4 in Figure 12. Figure 21 is a perspective view of the first connector in Figure 15 from another angle. Figure 22 is a perspective view of the second connector in Figure 15 from another angle. Figure 23 is a perspective view of the third connector in Figure 15 from another angle. Figure 24 is a perspective view of the seat in one embodiment of this application. Figure 25 is a partial structural schematic diagram of the winding mechanism on the seat shown in Figure 24. Figure 26 is a cross-sectional view along line U5-U5 in Figure 24. Figure 27 is a bottom view of the seat in another embodiment of this application. Figure 28 is a cross-sectional view of the seat shown in Figure 27. Figure 29 is an exploded view of the joint structure in the second embodiment of this application. Figure 30 is an exploded view of the joint structure in the sixth embodiment of this application. Figure 31 is an exploded view of the joint structure in the seventh embodiment of this application. Figure 32 is an exploded view of the joint structure in the eighth embodiment of this application. Figure 33 is an exploded view of the joint structure in the ninth embodiment of this application. Figure 34 is an exploded view of the joint structure in the tenth embodiment of this application. Figure 35 is an exploded view of the joint structure in the eleventh embodiment of this application. Figure 36 is a perspective view of the first connecting seat of the joint structure in the eleventh embodiment of this application. Figure 37 is a partial exploded view of the joint structure from another angle in the eleventh embodiment of this application. Figure 37 only retains the first connecting seat, the second connecting seat, and the third connecting seat. Figure 38 is a cross-sectional view of the trolley in the folded state in the eleventh embodiment of this application. Figure 39 is a cross-sectional view of the third limiting post in the eleventh embodiment of this application. Figure 40 is a perspective sectional view of the trolley in the extended state in the eleventh embodiment of this application. Specifically, Figure 40 shows the joint structure, the handframe, and the front wheel frame in cross-section. Figure 41 is a cross-sectional view of the trolley in the eleventh embodiment of this application when it is in a folded state and an extended state. Specifically, Figure 41 shows the cross-sectional view of the joint structure. Implementation

[0072] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0073] One embodiment of the present invention provides a trolley 1000, which may include a frame 100 and a cloth cover (not shown) fitted onto 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 joint structure 200 will be described in conjunction with the trolley 1000 and the frame 100 described below.

[0074] Figures 1 and 2 illustrate a trolley 1000 according to an embodiment of the present invention. The frame 100 of the trolley 1000 is generally symmetrical from left to right. The handlebar frame 110, front wheel frame 120, and rear wheel frame 130 of the frame 100 are respectively connected to two joint structures 200. The trolley 1000, through the two joint structures 200 located on the left and right sides, allows 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 trolley 1000 can have an extended state (see Figures 1 and 2) and a folded state (see Figure 14). When the trolley 1000 is needed, it can be in the extended state; when the trolley 1000 needs to be stored, it can be in the folded state to save space and facilitate storage.

[0075] Referring to Figures 1 and 2, in one embodiment, each of the joint structures 200 described above may include a first connecting seat 210, a second connecting seat 220, and a third connecting seat 230. The first connecting seat 210, the second connecting seat 220, and the third connecting seat 230 are pivotally connected to each other about an axial direction (the direction around the axial direction is circumferential, and the direction perpendicular to the axial direction is radial). At least a portion of the second connecting seat 220 is located axially between the first connecting seat 210 and the third connecting seat 230, so that the trolley 1000 has an extended state and a folded state. The first connecting seat 210 is used to connect to the handlebar frame 110, the second connecting seat 220 is used to connect to the front wheel frame 120, and the third connecting seat 230 is used to connect to the rear wheel frame 130, thus allowing the trolley 1000 to switch between an extended state and a folded state. Of course, in other embodiments, the second connecting seat 220 can be used to connect with the rear wheel frame 130, and the third connecting seat 230 can be used to connect with the front wheel frame 120. In this way, the trolley 1000 can also be switched between an extended state and a folded state. Specifically, when the trolley 1000 is in the extended state, the handlebar frame 110, the front wheel frame 120 and the rear wheel frame 130 are spaced apart circumferentially, and the rear wheel frame 130 is located circumferentially between the front wheel frame 120 and the handlebar frame 110. The front wheel frame 120 and the rear wheel frame 130 are set at a first included angle α1 (see Figure 3), and the handlebar frame 110 and the front wheel frame 120 are set at a second included angle α2 (see Figure 3). When the trolley 1000 is in the folded state, the handlebar frame 110 is circumferentially close to the rear wheel frame 130, the rear wheel frame 130 is circumferentially close to the front wheel frame 120, and the front wheel frame 120 and the rear wheel frame 130 are set at a third included angle α3 (see Figure 14), and the handlebar frame 110 and the front wheel frame 120 are set at a fourth included angle α4 (see Figure 14). Among them, the third included angle α3 is smaller than the first included angle α1, and the fourth included angle α4 is smaller than the second included angle α2.

[0076] To clearly understand the structure of the trolley 1000 shown in this invention, the specific structures of the front wheel frame 120, rear wheel frame 130, handlebar frame 110, and each joint structure 200 will be further described below.

[0077] Referring to Figures 1 and 2, in one embodiment, the front wheel frame 120 has, for example, a U-shaped structure, including front rods 121 located on the left and right sides and a front crossbar 122 connecting 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 be used as a footrest.

[0078] In one embodiment, the trolley 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 trolley 1000 includes two front wheel seats 141 mounted on the bottom of the front wheel frame 120, the two front wheel seats 141 being 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 crossbars 121 are respectively connected to the front wheel seats 141 on the same side. The trolley 1000 also includes at least one front wheel 151 mounted to the front wheel seat 141 to make the trolley 1000 movable. Specifically, in this embodiment, the trolley 1000 includes two front wheels 151, each front wheel seat 141 being used to mount one front wheel 151, wherein the front wheel 151 can be a caster wheel or a non-caster wheel. Of course, in other embodiments, the front wheel frame 120 may also have other implementation methods. For example, the front wheel frame 120 may only include two front rods 121, with one end of the two front rods 121 connected to form a V-shaped structure. The trolley 1000 may 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.

[0079] It should be noted that, unless otherwise explicitly specified and limited, the directional terms such as "left" and "right" related to the trolley 1000 in various embodiments of the present invention are based on the "left" and "right" orientation of the trolley 1000 during normal operation, and the "left" and "right" directions are schematically indicated by arrows L and R in the figures. These directional terms are only used to make the description of the embodiments of the present invention clearer and are not intended to unduly limit the scope of protection of the present invention.

[0080] Referring again to Figures 1 and 2, the rear wheel frame 130 may include two rear rods 131 located on the left and right sides, and a rear crossbar 132 connected between the two rear rods 131. The two rear rods 131 on the left and right sides are respectively connected to the front rod 121 on the same side through 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 trolley 1000 also includes at least one rear wheel seat 142 installed at the bottom of the rear wheel frame 130. Specifically, in this embodiment, the trolley 1000 includes two rear wheel seats 142 installed at 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 seats 142 are installed at the left and right ends of the rear crossbar 132 at the end of the rear rod 131, and the two rear rods 131 are respectively connected to the rear wheel seats 142 on the same side. The trolley 1000 also includes rear wheels 152 mounted to the rear wheel seats 142 to make the trolley 1000 movable. Specifically, in this embodiment, the trolley 1000 includes two rear wheels 152, and each rear wheel seat 142 is used to mount one rear wheel 152, wherein the rear wheel 152 may be, for example, a swivel wheel or a non-swivel wheel. In this embodiment, the size of the rear wheel 152 is larger than the size of the front wheel 151 to make the overall structure of the trolley 1000 more stable. Of course, in other embodiments, the size of the rear wheel 152 may be the same as or smaller than the size of the front wheel 151.

[0081] Optionally, in other embodiments, the rear wheel frame 130 may have other implementations. For example, the rear wheel frame 130 may only include two rear rods 131, with one end of the two rear rods 131 connected to form a V-shape. The trolley 1000 may install a rear wheel seat 142 at the end where the two rear rods 131 are connected. Alternatively, for example, the rear wheel frame 130 may only include 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.

[0082] Referring to Figures 1 and 2, the handframe 110 includes a first pusher frame 111, a second pusher frame 112, and two retractable joints 113. The second pusher frame 112 is pivotally connected to the first pusher frame 111 via the two retractable joints 113 on its left and right sides, so that the first pusher frame 111 can be unfolded (see Figure 3) or folded (see Figures 12 to 14) relative to the second pusher frame 112. Specifically, the first pusher frame 111 is, for example, generally U-shaped, and includes a pusher bar 1112 and two first support bars 1111. The two first support bars 1111 are arranged parallel to each other and spaced apart along a first direction F1. The pusher bar 1112 is U-shaped and connected between the two first support bars 1111, for the user to hold and push the cart 1000. More specifically, the second pusher frame 112 includes, for example, two second support rods 1121, which are spaced apart along the first direction F1. The upper ends of the two second support rods 1121 are pivotally connected to the lower ends of the first support rods 1111 on the same side via the retractable joints 113 on the same side, for example. The lower ends of the two second support rods 1121 are connected to the first connecting seats 210 in the joint structure 200 on the same side, for example.

[0083] Referring to Figures 4 to 6, in one embodiment, each retractable 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 pusher frame 111 (specifically, the first support rod 1111), and the sixth connecting seat 1132 is connected to the second pusher frame 112 (specifically, the second support rod 1121). The sixth connecting seat 1132 and the fifth connecting seat 1131 are pivotally connected to each other via a second pivot 1137, allowing the first pusher frame 111 to unfold or fold relative to the second pusher frame 112. To prevent the first pusher frame 111 from rotating arbitrarily relative to the second pusher frame 112, in one embodiment, as shown in Figures 4 and 6, the sixth connecting seat 1132 is provided with a locking groove 11321, and the fourth locking member 1133 is movably mounted on the first pusher frame 111. When the first pusher 111 and the second pusher 112 are unfolded relative to each other, the first pusher 111 is approximately parallel to the second pusher 112, meaning they are roughly on the same plane, and the angle between them is approximately 180 degrees (see Figures 2 and 3). At this time, the fourth locking member 1133 can be inserted into the locking groove 11321 to restrict the first pusher 111 from pivoting relative to the second pusher 112, thus allowing the first pusher 111 to remain stably unfolded relative to the second pusher 112. When the fourth locking member 1133 is removed from the locking groove 11321, the first pusher 111 can pivot relative to the second pusher 112 and fold, with the angle between them being an acute angle (see Figures 13 and 14) or approaching 0 degrees. Of course, in other embodiments, when the trolley 1000 is in the extended state, the included angle between the first pusher frame 111 and the second pusher frame 112 may also be an obtuse angle or an acute angle, and no specific limitation is made here.

[0084] To facilitate control of the fourth locking member 1133 disengaging from the locking groove 11321 so that the first pusher frame 111 can fold relative to the second pusher frame 112, in one embodiment, as shown in Figures 1, 3, and 4, the rider frame 110 further includes a release button 161 and a second traction member 162. The release button 161 is movably disposed on the first pusher frame 111 and is connected to the fourth locking member 1133 via the second traction member 162. When the release button 161 moves relative to the first pusher frame 111, the release button 161 drives the fourth locking member 1133 to move relative to the first pusher frame 111 via the second traction member 162 so that it can disengage from the locking groove 11321. The second traction member 162 can be, for example, a traction rope, with one end connected to the release button 161 and the other end connected to the fourth locking member 1133. Specifically, as shown in Figures 7 and 8, the release button 161 includes an operating part 1612, and the handrail 110 also includes a drive wheel 1611. The drive wheel 1611 is rotatably mounted on the first pusher frame 111 and connected to one end of the second traction member 162. The operating part 1612 is movably mounted on the first pusher frame 111 and connected to the drive wheel 1611, so that the release button 161 is indirectly connected to one end of the second traction member 162 through the drive wheel 1611. When the operating part 1612 moves relative to the first pusher frame 111, it can drive the drive wheel 1611 to rotate relative to the first pusher frame 111, thereby pulling the second traction member 162 to move so that the fourth locking member 1133 disengages from the locking groove 11321.

[0085] Referring to Figures 3 and 4, in one embodiment, the rider frame 110 further includes a fourth elastic member 163 disposed on the first pusher frame 111. The fourth elastic member 163 is, for example, a compression spring and abuts against the fourth locking member 1133, for driving the fourth locking member 1133 to reset so that the fourth locking member 1133 always has a tendency to insert into the locking groove 11321.

[0086] Referring to Figure 8, in one embodiment, the handrail 110 further includes a safety push button 164, which is movably disposed on the first handrail 111 and has a third position and a fourth position. When the safety push button 164 is in the third position, it abuts against the release button 161 to prevent the release button 161 from moving relative to the first handrail 111. Specifically, the safety push button 164 abuts against the operating part 1612 to prevent the operating part 1612 from moving relative to the first handrail 111, thereby preventing the drive wheel 1611 from rotating to drive the second traction member 162 to move. When the safety push button 164 is in the fourth position, it is spaced apart from the release button 161 to allow the release button 161 to move relative to the first handrail 111. The direction of movement of the safety push button 164 intersects with the direction of movement of the release button 161. Therefore, when the user needs to pivot the first pusher 111 relative to the second pusher 112 for folding, the user must first operate (e.g., toggle) the safety push button 164 to the fourth position before operating (e.g., pressing) the operating part 1612 to disengage the fourth locking member 1133 from the locking groove 11321. This prevents the rider 110 from accidentally folding due to the user's misoperation of the release button 161.

[0087] Referring to Figures 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 Figure 6, 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 the circumferential direction surrounding the second pivot 1137. The fifth locking member 1134 is movably disposed on the fifth connecting seat 1131. As shown in Figure 11, when the first pusher frame 111 is folded relative to the second pusher frame 112 and the fifth locking member 1134 is in the first position, the fifth locking member 1134 extends into the limiting recess 11322. This allows the first pusher frame 111 and the second pusher frame 112 to remain folded relative to each other, preventing the vehicle frame 110 from pivoting arbitrarily relative to the second pusher frame 112 after folding. As shown in Figures 9 and 10, when the fifth locking member 1134 is in the second position, the fifth locking member 1134 retracts from the limiting recess 11322. This allows the first pusher frame 111 to pivot relative to the second pusher frame 112, thus allowing the vehicle frame 110 to unfold.

[0088] Referring to Figures 6, 10, and 11, in this embodiment, the retractable joint 113 further includes a limiting cover 1135 and a third elastic member 1136. Specifically, the fifth connecting seat 1131 is provided with a movable hole 11311, and the fifth locking member 1134 is movably inserted into the movable hole 11311. The limiting cover 1135 is located 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 limiting cover 1135 and the fifth locking member 1134 to keep the fifth locking member 1134 in the first position.

[0089] Referring again to 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 ramp 11341 suitable for releasing the limiting position. Specifically, the end of the fifth locking member 1134 facing the limiting recess 11322 is provided with a sliding ramp 11341, and the inner wall of the limiting recess 11322 is also provided with a sliding ramp 11341. In this way, the fifth locking member 1134 can push against the limiting recess 11322 through the sliding ramp 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 away from the limiting recess 11322, which is equivalent to moving the fifth locking member 1134 from the first position to the second position.

[0090] The following, with reference to Figures 3 to 11, briefly explains the usage process and working principle of the retraction joint 113.

[0091] Referring to Figures 3, 4, and 10, when the handframe 110 is deployed, that is, when the first pusher frame 111 and the second pusher frame 112 are deployed relative to each other, the first pusher frame 111 and the second pusher frame 112 are approximately on the same plane, and the included angle between them is approximately 180 degrees. At this time, the locking groove 11321 on the sixth connecting seat 1132 is opposite to 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, which can restrict the pivoting of the fifth connecting seat 1131 relative to the sixth connecting seat 1132. At the same time, the fifth locking member 1134 abuts against the surface of the sixth connecting seat 1132 under the action of the third elastic member 1136.

[0092] Referring to Figures 7 and 8, when the user needs to fold the handlebar 110, the user first moves the safety push button 164 to the fourth position, and then presses the operating part 1612 upwards. The operating part 1612 pushes the drive wheel 1611 to rotate, thereby driving the second traction member 162 to move, which in turn drives the fourth locking member 1133 to move away from the sixth connecting seat 1132, so that the fourth locking member 1133 disengages from the locking groove 11321. At this time, the user can rotate the first push handlebar 111 to fold it relative to the second push handlebar 112. When the first push handlebar 111 is folded relative to the second push handlebar 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 handlebar 111 can be kept in a relatively folded state relative to the second push handlebar 112.

[0093] Referring to Figures 6, 10, and 11, since both the fifth locking member 1134 and the limiting recess 11322 are provided with sliding ramps 11341, when the user needs to unfold the rider frame 110, the user can directly rotate the first pusher frame 111. Under the guidance of the sliding ramps 11341, the fifth locking member 1134 can gradually move relative to the limiting recess 11322 and gradually exit from the limiting recess 11322. After the first pusher frame 111 unfolds relative to the second pusher frame 112, the fourth elastic member 163 drives the fourth locking member 1133 to insert into the locking groove 11321, so that the rider frame 110 remains in the unfolded state.

[0094] Referring to Figures 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 on a first pivot (not shown in the figure, the axis of the first pivot extends in the axial direction). In this way, the movement of the first connecting seat 210, the second connecting seat 220 and the third connecting seat 230 in the axial direction can be restricted, and the separation or detachment of the three in the axial direction can be avoided, thereby improving the stability of the joint structure 200 and the trolley 1000 structure.

[0095] 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 movably disposed 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 movably disposed in the joint structure 200 and has at least one locking portion 281, which extends in a direction parallel to the axial direction. The second locking member 280 has a second locking position and a second unlocking position. When the second locking member 280 is in the second locking 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, thus fixing the second connecting seat 220 and the third connecting seat 230 relatively. When the second locking member 280 is in the second unlocking position, the locking portion 281 passes through only 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 sleeved outside the first pivot and rotatable about the first pivot, and is axially movable between the first connecting seat 210 and the second connecting seat 220, having an initial position and an unlocking position. When the drive member 250 moves from the initial position to the unlocked position, it 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 drive member 250, the positions of the first locking member 240 and the second locking member 280 can be changed, thereby altering the relative states between the first connecting seat 210, the second connecting seat 220, and the third connecting seat 230, allowing the trolley 1000 to switch between an extended state and a folded state.

[0096] It should be noted that the aforementioned "at least one locking part 281" refers to the presence of one, two, or more locking parts 281, and when multiple locking parts 281 are provided, they can be spaced apart circumferentially. Specifically, in this embodiment, the second locking member 280 has a main body 282, and the locking parts 281 protrude from the main body 282 in a direction parallel to the axial direction. More specifically, the main body 282 has an annular structure for the passage of a first pivot, which is located at the center of the main body 282. The second locking member 280 has multiple locking parts 281, which are spaced apart at the circumferential edges of the main body 282. In this way, by having multiple locking parts 281 simultaneously pass through the third connecting seat 230 and the second connecting seat 220, the rotational movement of the second connecting seat 220 relative to the third connecting seat 230 about the first pivot can be further restricted, thereby improving the stability of the second locking member 280 in locking the second connecting seat 220 and the third connecting seat 230.

[0097] Referring to Figure 17, the second locking member 280 is provided with a plurality of locking portions 283 extending radially from the main body portion 282, and the plurality of locking portions 283 are spaced apart circumferentially.

[0098] In this embodiment, the driving member 250 and the first locking member 240 are arranged adjacent to each other. 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 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 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 from the first locked position to the first unlocked position. Simultaneously, the first locking member 240 can also indirectly drive the second locking member 280 from the second locked position to the second unlocked position.

[0099] Referring to Figures 15 and 16, in one embodiment, the driving member 250 drives the first locking member 240 to move along the positive axial direction to the second connecting seat 220, bringing it to a first unlocking position. As shown in Figure 19, when the first locking member 240 is in the first locking position, it engages with both the first connecting seat 210 and the second connecting seat 220, keeping them relatively fixed. As shown in Figure 20, when the first locking member 240 is in the first unlocking position, it engages with the second connecting seat 220 and disengages from the first connecting seat 210, 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 unlocking position of the first locking member 240 can be considered as the first locking member 240 being located within the second connecting seat 220.

[0100] Specifically, the first locking member 240 is a gear structure and can be passed through by the first pivot. As shown in Figures 21 and 22, the first connecting seat 210 has a generally annular first accommodating space 212 and a plurality of first locking grooves 213 spaced circumferentially around the first accommodating space 212 on the side facing the second connecting seat 220. The second connecting seat 220 has a generally annular second accommodating space 222 and a plurality of second locking grooves 223 spaced circumferentially around the second accommodating space 222 on the side facing the first connecting seat 210. When the first locking member 240 is in the first locked position, one end of the first locking member 240 along the axial direction is located in the first accommodating space 212 and the other end is located in the second accommodating space 222 (see Figure 19). In this way, 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 Figure 20), and the multiple protrusions on the outer periphery of the first locking member 240 are only received in the multiple second locking grooves 223 in a direction parallel to the axial direction.

[0101] 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 opposite direction along the axial direction.

[0102] Referring to Figures 16 to 18, in this embodiment, the main body 282 of the second locking member 280 is located on the side of the third connecting seat 230 opposite to the second connecting seat 220. When the second locking member 280 is in the second locked position, the locking part 281 passes through the third connecting seat 230 and the second connecting seat 220 sequentially 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 part 281 to move in a direction parallel to the positive axial direction until the locking part 281 disengages from the second connecting seat 220. In this way, the locking part 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 regarded as the second locking member 280 being located between the third connecting seat 230 and the fourth connecting seat 290 (see below) or within the fourth connecting seat 290.

[0103] Referring to Figures 2, 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 a first pivot. 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 movably disposed between the third connecting seat 230 and the fourth connecting seat 290, and has a third locking position and a third unlocking position. Specifically, when the third locking member 310 is in the third locking position, the third connecting seat 230 and the fourth connecting seat 290 are relatively fixed; when the third locking member 310 is in the third unlocking 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 unlocking position, the driving member 250 drives the third locking member 310 to move from the third locking position to the third unlocking position.

[0104] Although in this embodiment, the first connecting seat 210, the second connecting seat 220, the third connecting seat 230, and the fourth connecting seat 290 all rotate about an axial direction, in other embodiments, the first connecting seat 210 and the second connecting seat 220 may rotate about a first axial direction, the second connecting seat 220 and the third connecting seat 230 may rotate about a second axial direction, and the third connecting seat 230 and the fourth connecting seat 290 may rotate about a third axial direction, with the first, second, and third axial directions being parallel but not coaxial. Alternatively, the first connecting seat 210, the second connecting seat 220, and the third connecting seat 230 may rotate about a first axial direction, while the fourth connecting seat 290 and the third connecting seat 230 may rotate about a second axial direction, wherein the first and second axial directions are parallel but not coaxial.

[0105] It should be noted that in this embodiment, the driving member 250 indirectly drives the third locking member 310 to move from the third locked position to the third unlocked position. For example, the driving member 250 indirectly drives the movement of the third locking member 310 through 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 seat 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 to move from the third locked position to the third unlocked position (switching from Figure 19 to Figure 20). Therefore, in this embodiment, when the driving member 250 moves from the initial position to the unlocked position, it directly drives the first locking member 240 to leave the first locked position and reach the first unlocked position. Then, through the unlocked first locking member 240, the driving member 250 continues to indirectly cause the second locking member 280 to move from the second locked position to the second unlocked position. Finally, through the further transmission of the second locking member 280, the third locking member 310 is able to move from the third locked position to the third unlocked position.

[0106] In one embodiment, when the locking portion 281 on the third locking member 310 moves to disengage 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 and to the third unlocking position. In other words, the third unlocking 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 unlocking position, the third locking member 310 is engaged with the fourth connecting seat 290 and disengaged from the third connecting seat 230, allowing the fourth connecting seat 290 to pivot relative to the third connecting seat 230.

[0107] Specifically, the third locking member 310 is a gear structure and can be passed through by the first pivot. As shown in Figures 17, 19, and 20, the third connecting seat 230 has a generally annular third accommodating space 232 on the side facing the fourth connecting seat 290, and a plurality of third locking grooves 233 arranged circumferentially around the third accommodating space 232. The fourth connecting seat 290 has a generally annular fourth accommodating space 291 on the side facing the third connecting seat 230, and a plurality of fourth locking grooves 292 arranged circumferentially around the fourth accommodating space 291. When the third locking member 310 is in the third locked position, one end of the third locking member 310 along the axial direction is located in the third accommodating space 232, and the other end is located in the fourth accommodating space 291 (see Figure 19). In this way, 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 protrusions on the outer periphery of the third locking member 310 are only received in the multiple fourth locking grooves 292 in a direction parallel to the axial direction.

[0108] Referring to Figures 15 to 18, in one embodiment, a first elastic member 260 is provided between the first locking member 240 and the second connecting seat 220. The first elastic member 260 provides an elastic restoring force to the first locking member 240, so that the first locking member 240 is held in the first locked position. Thus, under the restoring force of the first elastic member 260, the first locking member 240 can automatically move from the first unlocked position to the first locked position, and thereby cause the driving member 250 to move from the unlocked position to the initial position. Optionally, the first elastic member 260 is a compression spring, with its two ends abutting between the second connecting seat 220 and the first locking member 240.

[0109] Referring again to Figures 15 to 18, in one embodiment, a second elastic member 320 is provided between the third locking member 310 and the fourth connecting seat 290. The second elastic member 320 provides an elastic restoring force to the third locking member 310, so that the third locking member 310 is held in the third locked position. In this way, the first elastic member 260 can drive the first locking member 240 to automatically move from the first unlocking position to the first locking position. Thus, the first locking member 240 releases its pressure on the second locking member 280. The second elastic member 320 can then drive the third locking member 310 to automatically move from the third unlocking position to the third locking position, and further drive the second locking member 280 to move from the second unlocking position to the second locking position, ultimately restricting relative rotation among the first connecting seat 210, the second connecting seat 220, the third connecting seat 230, and the fourth connecting seat 290, thereby maintaining relative fixation. Similarly, the second elastic member 320 can be a compression spring, with its two ends abutting between the fourth connecting seat 290 and the third locking member 310.

[0110] Referring to Figures 1, 2, and 19, in one embodiment, the trolley 1000 further includes a seat 170 (the specific structure of which can be seen below), and the seat 170 is connected to the fourth connecting seat 290. Specifically, when the trolley 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 trolley 1000 is in the folded state, the seat 170 and the rear wheel frame 130 are arranged at a sixth angle (not shown in the figure), wherein the sixth angle is smaller than the fifth angle α5.

[0111] The following diagrams will briefly explain the usage and working principle of the joint structure 200.

[0112] Referring to Figures 3 and 19, in this embodiment, when the trolley 1000 is in the extended state, the drive member 250 is in the initial position, the first locking member 240 is in the first locked 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 locked position, and the locking portion 281 passes through the second connecting seat 220 and the third connecting seat 230 to keep them relatively fixed. Additionally, the third locking member 310 is in the third locked 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 trolley 1000 can be stably maintained in the extended state.

[0113] When the trolley 1000 needs to be switched from an extended state to a folded state (switching sequentially from Figure 3 to Figures 12, 13, and 14), the drive member 250 can be gradually moved towards the unlocked position. During the movement, the drive member 250 directly drives the first locking member 240 to the first unlocked position. At the same time, the drive member 250 can indirectly drive the second locking member 280 to the second unlocked position through the first locking member 240. In addition, the drive member 250 can also indirectly drive the third locking member 310 to the third unlocked position through the second locking member 280. When the drive member 250 moves to the unlocked position, the first locking member 240 is in the first unlocked position, the first elastic member 260 is in a compressed state, and the first connecting seat 210 can rotate relative to the second connecting seat 220 to bring the handrail 110 and the front wheel frame 120 closer together. Simultaneously, the second locking member 280 is in the second unlocked position, and the locking part 281 retracts from the second connecting seat 220. Thus, the second connecting seat 220 can rotate relative to the third connecting seat 230, 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, the second elastic member 320 is in a compressed state, and the fourth connecting seat 290 can rotate relative to the third connecting seat 230, bringing the seat 170 and the rear wheel frame 130 closer together.

[0114] When the trolley 1000 needs to be switched from a folded state to an extended state, the seat 170, rear wheel frame 130, front wheel frame 120, and handlebar frame 110 can be rotated to return them to their positions corresponding to when the trolley 1000 is in the extended state, thereby causing the corresponding connecting seats to rotate around the first pivot. During this process, the second elastic member 320 gradually resets and pushes the third locking member 310 to move to the third locking position, so that the fourth connecting seat 290 is fixed 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 move to the second locking position, which is equivalent to pushing the locking part 281 through the third connecting seat 230 and the second connecting seat 220 in a direction parallel to the axial direction, thereby restricting the pivoting between the third connecting seat 230 and the second connecting seat 220. In addition, the first elastic element 260 gradually resets and pushes the first locking element 240 to move toward the first locking position, thereby restricting the pivoting between the second connecting seat 220 and the first connecting seat 210.

[0115] As described above, when the trolley 1000 switches between a folded state and an extended state, the handlebar frame 110, front wheel frame 120, rear wheel frame 130 and seat 170 connected to the joint structure 200 will rotate with the corresponding connecting seats so that the trolley 1000 can switch between an extended state and a folded state.

[0116] To facilitate user control of the position of the drive unit 250, referring to Figures 6 and 16, in one embodiment, the drive unit 250 is connected to the handframe 110 via a first traction member 270. Specifically, in this embodiment, the drive unit 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, with one end connected to the fifth connecting seat 1131 and the other end connected to the drive unit 250. Therefore, when the first handframe 111 pivots relative to the second handframe 112, the fifth connecting seat 1131 will pivot relative to the sixth connecting seat 1132. This causes the end of the traction rope connected to the fifth connecting seat 1131 to rotate, thereby driving the drive unit 250 to rotate around the first pivot.

[0117] To achieve the conversion of the drive member 250 from rotational motion to axial motion, in one embodiment, as shown in Figures 16 and 21, the drive 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 pushing portion 214, which protrudes in a direction parallel to the axial direction and extends obliquely in the circumferential direction. Specifically, the pushing portion 214 protrudes from the bottom wall of the first accommodating space 212 within the first connecting seat 210 toward the drive member 250. The abutment portion 251 and the pushing portion 214 abut against each other in a direction parallel to the axial direction. Specifically, when the trolley 1000 is in the extended state, the abutment portion 251 and the pushing portion 214 are engaged with each other. When the trolley 1000 switches from the extended state to the folded state, the first pusher 111 pivots relative to the second pusher 112 around the second pivot 1137 (switching from Figure 3 to Figure 12). During this process, the fifth connecting seat 1131 drives one end of the first traction member 270 to rotate around the second pivot 1137, thereby driving the drive member 250 to rotate relative to the first connecting seat 210 in the circumferential direction around the first pivot. Under the mutual pushing of the abutment part 251 and the pusher part 214, the drive member 250 can move in the positive axial direction, so that the drive member 250 moves from the initial position to the unlocked position.

[0118] In this embodiment, when the user needs to fold the trolley 1000, the user first pushes the safety push button 164 to move it to the fourth position. Then, the user operates the release button 161 to drive the fourth locking member 1133 out of the locking groove 11321. In this way, the first pusher 111 and the second pusher 112 can be folded together by rotating the first pusher 111. During this process, the fifth connecting seat 1131 will rotate around the second pivot 1137, thereby driving the first traction member 270 to move, and finally causing the driving member 250 to rotate around the first pivot. Since the driving member 250 is provided with an abutment part 251, when the driving member 250 rotates, the abutment part 251 abuts against the push part 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 drive unit 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 time, the first connecting seat 210 can rotate relative to the second connecting seat 220, the second connecting seat 220 can rotate relative to the third connecting seat 230, and the third connecting seat 230 can rotate relative to the fourth connecting seat 290. In this way, the trolley 1000 can switch from an extended state to a folded state.

[0119] 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 Figure 21), the second connecting seat 220 is provided with a second limiting post 221 extending in a direction parallel to the axial direction (see Figures 16 and 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 Figures 17 and 23), and the first limiting post 211, the third limiting post 231, and the second limiting post 221 are arranged sequentially in the circumferential direction. When the trolley 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 against at least one of the first limiting post 211 and the second limiting post 221. Specifically, in this embodiment, as shown in Figure 3, the third limiting post 231 abuts against the first limiting post 211 and the second limiting post 221 respectively. 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. It can be seen that when the trolley 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 of the third limiting post 231 with the first limiting post 211 and the second limiting post 221 can further achieve the stable fixation of the second connecting seat 220 relative to the third connecting seat 230. In this way, the stability and reliability of the trolley 1000 in the extended state can be improved. As shown in Figure 14, when the trolley 1000 is in the folded state, the first limiting post 211, the third limiting post 231 and the second limiting post 221 are arranged circumferentially at intervals. At this time, the third connecting seat 230 can pivot relative to the first connecting seat 210 and the second connecting seat 220.

[0120] Specifically, as shown in Figures 16, 17, and 21 to 23, in this embodiment, the first limiting post 211 protrudes towards the second connecting seat 220 in a direction parallel to the axial direction, the second limiting post 221 protrudes towards the first connecting seat 210 in a direction parallel to the axial direction, and the third limiting post 231 protrudes towards 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 can move circumferentially within the second connecting seat 220. Specifically, when the trolley 1000 is in a folded state, the third limiting post 231 abuts circumferentially against the groove wall of the movable groove 224 on the side away from the second limiting post 221 (see Figure 14).

[0121] It should be explained that the first limiting post 211 protrudes towards the second connecting seat 220 and is spaced apart axially; specifically, the first limiting post 211 protrudes from the bottom wall of the first accommodating space 212 within the first connecting seat 210 towards the second connecting seat 220. The second limiting post 221 protrudes towards the first connecting seat 210 and is spaced apart axially; specifically, the second limiting post 221 protrudes from the bottom wall of the second accommodating space 222 within the second connecting seat 220 towards the first connecting seat 210. The third limiting post 231 protrudes towards the first connecting seat 210 and passes through the second connecting seat 220, and is spaced apart axially; specifically, the third limiting post 231 protrudes from the surface of the third connecting seat 230 facing the second connecting seat 220 towards 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 in a direction parallel to the axial direction is only a preferred embodiment.

[0122] Referring to Figures 3, 13, and 14, in one embodiment, the first locking member 240 and the driving member 250 are both located on one radial 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 outside the first limiting post 211, the second limiting post 221, and the third limiting post 231, which can be considered as the first locking member 240 and the driving member 250 being movably sleeved on the outside of the first limiting post 211, the second limiting post 221, and the third limiting post 231. In this way, interference can be avoided between the axial movement or rotation of the first locking member 240 and the driving member 250 and the circumferential movement of each limiting post.

[0123] To ensure the trolley 1000 remains stably folded after being folded, referring to 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 located circumferentially 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 that is circumferentially away from the third limiting post 231. When the trolley 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 closest to the second limiting post 221 (see Figure 14). In this way, the first connecting seat 210 can be rotated relative to the second connecting seat 220 and remain fixed, thereby restricting the movement of the handcart frame 110 away from the rear wheel frame 130. When the trolley 1000 is in the extended state, the first locking member 215 is located on the side of the second locking member 225 near the first limiting post 211, and is spaced apart from the second locking member 225 (see Figure 3).

[0124] Referring to Figures 3, 14, 21, and 22, in one embodiment, the second engaging member 225 is an engaging protrusion that extends towards the first connecting seat 210 in a direction parallel to the axial direction. The engaging protrusion has an engaging portion 2255. Specifically, the second engaging member 225 extends from the bottom wall of the second accommodating space 222 within the second connecting seat 220 towards the first connecting seat 210. The first engaging member 215 includes an elastic arm 2151 and a protrusion 2153. A hollowed-out deformation portion 2152 is formed in the middle of the elastic arm 2151, which allows the elastic arm 2151 to have an elastic force that deforms radially. The protrusion 2153 is located radially inner to the elastic arm 2151. When the trolley 1000 is in the folded state, the elastic arm 2151 is at least partially located radially outside the second engaging member 225, and the protrusion 2153 abuts against the second engaging member 225 on the side near the second limiting post 221. Specifically, at least one of the protrusion 2153 and the engaging protrusion is provided with a guide ramp 2256. Thus, when the trolley 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 ramp 2256 guides the first engaging member 215 to move from the side of the second engaging member 225 near the first limiting post 211 to the side of the second engaging member 225 near the second limiting post 221. More specifically, the first connecting seat 210 has a protruding ridge 217 extending toward the second connecting seat 220. Specifically, the protruding ridge 217 extends from the bottom wall of the first accommodating space 212 within the first connecting seat 210 toward the second connecting seat 220. The protruding ridge 217 is arranged axially, that is, the protruding ridge 217 is arranged circumferentially. The first engaging member 215 is disposed on the inner circumferential surface of the protruding ridge 217 and protrudes toward its axial position. That is, the elastic arm 2151 is connected to the inner circumferential surface of the protruding ridge 217, and the first limiting post 211 is also connected to the inner circumferential surface of the protruding ridge 217. More specifically, the engaging protrusion is generally cubic in structure, which includes an inner wall 2251 and an outer wall 2252 arranged radially, and a first side wall 2253 and a second side wall 2254 connecting the inner wall 2251 and the outer wall 2252. The outer wall 2252 and the first side wall 2253 form a guide slope 2256 through an arc transition, and the outer wall 2252 and the second side wall 2254 form a locking part 2255 through an arc transition. As shown in Figures 3, 13, and 14, when the trolley 1000 switches from an extended state to a folded state, the first connecting seat 210 rotates clockwise around the first pivot, so that the first locking member 215 gradually approaches and engages with the second locking member 225. During this process, the protrusion 2153 gradually abuts against the guide slope 2256 and moves towards the outer wall 2252. During the abutment process, the protrusion 2153 is squeezed, causing the elastic arm 2151 to deform and concave into the deformation part 2152.When the protrusion 2153 passes the outer wall 2252 and reaches the engaging portion 2255, the elastic arm 2151 resets to drive the protrusion 2153 to engage with the engaging portion 2255. Thus, when the trolley 1000 is in a folded state, under conditions of no external force or minimal external force, the first connecting seat 210 and the second connecting seat 220 can remain relatively fixed, preventing the handcart frame 110 from pivoting arbitrarily relative to the front wheel frame 120.

[0125] Referring to Figures 3, 13, and 14, when the trolley 1000 transitions from an extended state to a folded state, the rider frame 110 is first rotated towards the front wheel frame 120, causing the first limiting post 211 to move away from the third limiting post 231 in the positive circumferential direction (i.e., the direction in which the first limiting post 211 moves away from the third limiting post 231 in the positive circumferential direction). Simultaneously, the rider frame 110 gradually rotates towards the rear wheel frame 130. When the rider... When frame 110 abuts against rear wheel frame 130, it will push rear wheel frame 130 to move together towards front wheel frame 120, so that third limiting post 231 moves along the positive circumferential direction towards the groove wall of movable groove 224 away from second limiting post 221, until protrusion 2153 engages with engaging part 2255 along the positive circumferential direction, and third limiting post 231 abuts against the groove wall of movable groove 224 away from second limiting post 221 along the positive circumferential direction, and trolley 1000 reaches folded state.

[0126] Referring to Figures 3, 13, and 14, when the trolley 1000 transitions from a folded state to an extended state, the handlebar frame 110 is first rotated away from the front wheel frame 120, causing the first limiting post 211 to move in the opposite direction of the circumference toward the third limiting post 231 (that is, the direction in which the first limiting post 211 moves toward the third limiting post 231 in the opposite direction of the circumference). Simultaneously, the protrusion 2153 also disengages from the engaging part 2255 in the opposite direction of the circumference, until the first limiting post 211 abuts against the third limiting post 231 in the opposite direction of the circumference. Position post 231, first limiting post 211 can push third limiting post 231 in the opposite circumferential direction, so that third limiting post 231 can slide in the movable groove 224 in the opposite circumferential direction toward the groove wall of the movable groove 224 near the side of second limiting post 221, until first locking member 240 is in the first locked position, so that the relative positional relationship between first limiting post 211 and second limiting post 221 is fixed, and third limiting post 231 will at least abut against first limiting post 211 in the circumferential direction, at which time trolley 1000 reaches the extended state. In the embodiment shown in FIG3, when trolley 1000 reaches the extended state, third limiting post 231 also abuts against second limiting post 221 in the circumferential direction, that is, third limiting post 231 is clamped between first limiting post 211 and third limiting post 231 in the circumferential direction.

[0127] Referring to Figure 2, in one embodiment, the outer side of the second connecting seat 220 is provided with a first blocking part 226, and the outer side of the third connecting seat 230 is provided with a second blocking part 234. When the driving member 250 is in the unlocked position, the first locking member 240 is in the first unlocked position, and the rear wheel frame 130 is spaced apart from the front wheel frame 120 in the circumferential direction, the first blocking part 226 and the second blocking part 234 abut against each other in the circumferential direction so that the included angle between the front wheel frame 120 and the rear wheel frame 130 is maintained at the first included angle α1. In this way, it can be avoided that after the trolley 1000 is folded down by the first push handle 111, the front wheel frame 120 and the rear wheel frame 130 will pivot relative to each other because there is no mutual obstruction, which would cause the front wheel frame 120 and the rear wheel frame 130 to unfold in a horizontal state (i.e., the included angle between the front wheel frame 120 and the rear wheel frame 130 is close to 180 degrees), affecting the folding effect. Simultaneously, the first blocking portion 226 and the second blocking portion 234 abut against each other circumferentially, which also serves to indicate to the user that the front wheel carrier 120 and the rear wheel carrier 130 are in positions where the second locking member 280 can be inserted axially into the second connecting seat 220 and the third connecting seat 230. Referring again to Figure 2, specifically, the first blocking portion 226 is located on the outer periphery of the second connecting seat 220, extends towards the third connecting seat 230 in a direction parallel to the axial direction, and protrudes outward relative to the outer periphery of the second connecting seat 220. The second blocking portion 234 is located on the outer periphery of the third connecting seat 230, extends towards the second connecting seat 220 in a direction parallel to the axial direction, and protrudes outward relative to the outer periphery of the third connecting seat 230.

[0128] Referring again to Figure 2, in one embodiment, the outer periphery of the third connecting seat 230 is further provided with a third blocking portion 235, and the outer periphery of the fourth connecting seat 290 is provided with a fourth blocking portion 293. The third blocking portion 235 and the fourth blocking portion 293 abut against each other circumferentially 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 engage axially with the third connecting seat 230 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 outer periphery of the third connecting seat 230, and 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 outer periphery of the fourth connecting seat 290.

[0129] Referring again to Figure 2, in one embodiment, the second blocking part 234 and the third blocking part 235 are arranged opposite to each other and connected in a direction parallel to the axial direction. Of course, in other embodiments, the second blocking part 234 and the third blocking part 235 may be integrally formed, or the second blocking part 234 and the third blocking part 235 may be spaced apart and not connected. 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 part 226 and the fourth blocking part 293 are arranged opposite to each other in a direction parallel to the axial direction.

[0130] Referring to Figures 18 and 24, in one embodiment, the seat 170 includes a seat plate 171, a retractable shoulder strap 172 passing through the seat plate 171, and a retractable mechanism 173 connected to both ends of the retractable shoulder strap 172. The two ends of the retractable shoulder strap 172 pass through the seat plate 171, extending from a first surface to a second surface, and are connected to the retractable mechanism 173 located on the second surface. The retractable mechanism 173 automatically tightens the retractable shoulder strap 172. The first and second surfaces are positioned 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. The retractable mechanism 173 is positioned on the second surface, thus avoiding the retractable mechanism 173 occupying the child's seating space. When the stroller 1000 is folded and the user needs to transfer the stroller 1000 by carrying it on their back, the user can directly pull the folding shoulder strap 172, which will automatically extend from the retracting mechanism 173. The extended folding shoulder strap 172 can be carried or lifted by the user. When the stroller 1000 does not need to be transferred, the user does not need to use the folding shoulder strap 172. The retracting mechanism 173 can automatically tighten the folding shoulder strap 172, which is equivalent to automatically retracting the folding shoulder strap 172. This can prevent too much of the folding shoulder strap 172 from protruding on the seat 171 and affecting the child's riding comfort.

[0131] Specifically, referring to Figures 25 and 26, the winding 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. Thus, the reel 1731 can rotate as the coil spring 1732 is wound up. Specifically, both ends of the retractable shoulder strap 172 pass through the seat plate 171 and are connected to the reel 1731, with the connection points between the two ends of the retractable shoulder strap 172 and the reel 1731 positioned opposite each other along the circumferential direction of the reel 1731. More specifically, in this embodiment, the reel 1731 has two openings 17311 around its circumference. The ends of the folding shoulder strap 172 pass through the two openings 17311 respectively to form a knot 1721 (such as a ball knot or a bow). In this way, the knot 1721 can be engaged with the edge of the opening 17311 so that the folding shoulder strap 172 is connected to the reel 1731.

[0132] Referring to Figures 24 and 25, in one embodiment, the winding mechanism 173 further includes a cover 1733, which is generally circular and is mainly used to cover the reel 1731 and the coil spring 1732 to prevent these structures from being exposed. This not only improves the aesthetics of the trolley 1000 but also prevents users or children from accidentally touching the reel 1731 and the coil spring 1732. Of course, in other embodiments, the cover 1733 can also be of other shapes, as shown in Figures 27 and 28. The 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 extends approximately along the extension direction of the folding strap 172 on the second surface.

[0133] 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 mounted on the second surface of the seat plate 171. The working principle of the guide wheel 1734 and the steering wheel 1735 is briefly explained below, taking the winding of one end of the shoulder 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 winding path of the shoulder strap 172. It should be noted that the rotation axis of the steering wheel 1735 is parallel to the rotation axes of the reel 1731 and the coil spring 1732. After one end of the retractable shoulder strap 172 passes through the seat plate 171, it first passes through the gap between the guide wheel 1734 and the second surface. This reduces friction on the retractable shoulder strap 172 and facilitates its movement. Then, it passes around the steering wheel 1735 and enters the opening 17311 of the reel 1731 to connect with the reel 1731. Since the rotation axes of the guide wheel 1734 and the steering wheel 1735 are perpendicular, as the retractable shoulder strap 172 moves from the guide wheel 1734 to the steering wheel 1735, it gradually switches from being parallel to the second surface to being perpendicular to the second surface. After one end of the retractable shoulder strap 172 passes through the steering wheel 1735, the retractable shoulder strap 172 can be tangential to the rotation of the reel 1731, facilitating winding.

[0134] Referring again to Figure 28, in one embodiment, the winding mechanism 173 further includes at least one set of guide ribs 1736. The set of guide ribs 1736 includes two oppositely arranged guide ribs 1736, with the shoulder strap 172 passing 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. This set of guide ribs 1736 assists in winding the shoulder strap 172, changing its position from parallel to the second surface to perpendicular to the second surface. Furthermore, a set of guide ribs 1736 is also provided between the steering wheel 1735 and the reel 1731. This set of guide ribs 1736 assists in winding the shoulder strap 172 onto the reel 1731.

[0135] Referring to Figure 29, the second embodiment of the present invention provides a joint structure 200, which can be considered a variation of the joint structure 200 in the first embodiment. The main difference is 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 component (which can be called a rotating seat 330). Unless otherwise specified, the working principles of each component in this joint structure 200 can be found in the working principles of the corresponding components in the joint structure 200 of the first embodiment described above, and will not be repeated here. Thus, this joint structure 200 can still achieve both unfolding and folding; therefore, the trolley 1000 using this joint structure 200 can also switch between an extended state and a folded state. It should be noted that in the trolley 1000 using the joint structure 200 shown in the second embodiment, the handlebar 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, it will drive the seat 170 to pivot simultaneously relative to both the front wheel frame 120 and the rear wheel frame 130 to achieve folding.

[0136] The third embodiment of the present invention provides a joint structure 200 (not shown in the figure). This joint structure 200 can also be regarded as a variation of the joint structure 200 in the first embodiment, the main difference being 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 only achieved by the second locking member 280. Therefore, unless otherwise specified, the working principle of each component in this joint structure 200 can be referred to the working principle of the corresponding component in the joint structure 200 of the first embodiment above, and will not be repeated here.

[0137] The fourth embodiment of the present invention provides a joint structure 200 (not shown in the figure). This joint structure 200 can also be regarded as a variation of the joint structure 200 in the first embodiment. The main difference is 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 disposed in the rotating seat 330, and the second elastic member 320 abuts against the inner wall of the rotating seat 330 and the second locking member 280, so that the locking part 281 of the second locking member 280 always has a tendency to pass through the rotating seat 330 and insert into the second connecting seat 220. Therefore, unless otherwise specified, the working principle of each component in this joint structure 200 can be referred to the working principle of the corresponding component in the joint structure 200 of the first embodiment above, and will not be repeated here. It should be noted that in the trolley 1000 using the joint structure 200 shown in the fourth embodiment, the handlebar 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, it will drive the seat 170 to pivot simultaneously relative to both the front wheel frame 120 and the rear wheel frame 130 to achieve folding.

[0138] The fifth embodiment of the present invention provides a joint structure 200 (not shown in the figure). This joint structure 200 can also be regarded as a variation of the joint structure 200 in the first embodiment. The main difference is that when the second locking member 280 is in the second locked position, the second locking member 280 passes through the third connecting seat 230, the second connecting seat 220, and the first locking member 240 in sequence and directly abuts against the driving member 250. In this way, 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 to move from the first locked position to the first unlocked position, and at the same time, it can also directly drive the second locking member 280 to move from the second locked position to the second unlocked position.

[0139] 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 arranged radially at intervals from the abutting portion 251 of the driving member 250, and the locking portion 281 protrudes towards 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. Unless otherwise specified, the working principle of each component in this joint structure 200 can be referred to the working principle of the corresponding component 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 first embodiment described above.

[0140] Specifically, in this embodiment, when the driving member 250 is in the initial position, the driving member 250 is located inside 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 part 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 sequence, and abuts against the third locking member 310, so that the third locking member 310 is in the third locking position, that is, the third locking member 310 is engaged with the third connecting seat 230 and the fourth connecting seat 290 at the same time.

[0141] When the driving member 250 moves from the initial position to the unlocked position, it can drive the second locking member 280 and the first locking member 240 to move in the opposite direction of the axial direction, so that the locking part 281 of the second locking member 280 disengages from the third connecting seat 230, and at the same time, the first locking member 240 moves into the first connecting seat 210 to reach the first unlocking position. During the movement of the locking part 281 in a direction parallel to the opposite direction of the axial direction, it gradually stops abutting against the third locking member 310. Under the reset action of the second elastic member 320, the second elastic member 320 can drive the third locking member 310 to move into the third connecting seat 230 to reach the third unlocking position. It should be noted that in this embodiment, the first unlocking position of the first locking member 240 is located within the first connecting seat 210, the third unlocking position of the third locking member 310 is located within the third connecting seat 230, and the first traction member 270 passes through the second connecting seat 220 and is installed within the front wheel frame 120.

[0142] 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 there is a gap 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 keep the first connecting seat 210 and the second connecting seat 220 fixed, and the second locking member 280 is pushed back to the second locking position to keep the second connecting seat 220 and the third connecting seat 230 fixed. When the second locking member 280 is in the second locking position, the locking part 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 sequence, and pushes the third locking member 310 to be in the third locking position, thereby finally keeping the third connecting seat 230 and the fourth connecting seat 290 fixed.

[0143] Referring to Figure 31, the seventh embodiment of the present invention provides a joint structure 200, which can be considered 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 locked 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 locked position, and the locking part 281 passes through the periphery of the driving member 250 and through the second connecting seat 220 to enter the rotating seat 330. Unless otherwise specified, the working principle of each component in this joint structure 200 can be referred to the working principle of the joint structure 200 in the first embodiment and the corresponding components in the sixth embodiment described above, and will not be repeated here. Thus, the joint structure 200 can still be unfolded and folded, so the trolley 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 trolley 1000 using the joint structure 200 shown in the seventh embodiment, the handlebar 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, it will cause the seat 170 to pivot simultaneously relative to both the front wheel frame 120 and the rear wheel frame 130 to achieve folding.

[0144] Referring to Figure 32, the eighth embodiment of the present invention provides a joint structure 200, which can be regarded as a variation of the joint structure 200 in the first embodiment. The main difference is 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 component (which can be called a rotating seat 330). In addition, 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. The second elastic member 320 (not shown in Figure 32) is located in the rotating seat 330 to abut against the locking portion 281 so that the locking portion 281 always has a tendency to retract from the rotating seat 330. The first elastic member 260 abuts between the first connecting seat 210 and the first locking member 240. Therefore, without conflict, the working principles of each component in the joint structure 200 can be found in the working principles of the corresponding components in the joint structure 200 of the first embodiment described above, and will not be repeated here. The following mainly describes the differences between this embodiment and the first embodiment described above.

[0145] Specifically, in this embodiment, when the driving member 250 is in the initial position, the driving member 250 is located inside 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 part 281 passes through the second connecting seat 220 in sequence to enter the rotating seat 330 to abut against the second elastic member 320 inside the rotating seat 330.

[0146] When the driving member 250 moves from the initial position to the unlocked position, it can drive the first locking member 240 to move in the opposite direction of the axial direction, so that the first locking member 240 moves into the first connecting seat 210 to reach the first unlocking position. Since the driving member 250 gradually stops abutting against the second locking member 280 during the reverse axial movement, and a gap remains between them, under the reset action of the second elastic member 320, the second elastic member 320 can drive the locking part 281 of the second locking member 280 to exit from the rotating seat 330. It should be noted that in this embodiment, the first unlocking position is located within the first connecting seat 210, and the first traction member 270 passes through the second connecting seat 220 and is mounted within the front wheel frame 120.

[0147] When the driving member 250 moves from the unlocked position to the initial position, it pushes the second locking member 280 to move in the positive axial direction to the second locking position. The locking part 281 passes through the second connecting seat 220 and enters the rotating seat 330 to abut against the second elastic member 320, so that the second connecting seat 220 and the rotating seat 330 remain relatively fixed. 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 gap between the driving member 250 and the first locking member 240, under the reset force of the first elastic member 260, the first locking member 240 is driven to move to the first locking position, so that the first connecting seat 210 and the second connecting seat 220 remain relatively fixed.

[0148] It should also be noted that in the trolley 1000 using the joint structure 200 shown in the eighth embodiment, the hand 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, it will drive the seat 170 to pivot simultaneously relative to both the front wheel frame 120 and the rear wheel frame 130 to achieve folding.

[0149] Referring to Figure 33, the ninth embodiment of the present invention provides a joint structure 200, which can be considered a variation of the joint structure 200 in the eighth embodiment described above. The main difference lies in changing the position of the second elastic member 320. In this embodiment, the second elastic member 320 is located between the second locking member 280 and the second connecting seat 220. Therefore, unless otherwise specified, the working principle of each component in this joint structure 200 can be found in the working principle of the corresponding component in the joint structure 200 of the eighth embodiment described above, and will not be repeated here.

[0150] Referring to Figure 34, the tenth 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 second connecting seat 220. The locking portion 281 of the second locking member 280 protrudes towards 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 elastic restoring force for the second locking member 280 so that the second locking member 280 is held in the first unlocking position. The first elastic member 260 abuts between the first locking member 240 and the first connecting seat 210. Unless otherwise specified, the working principle of each component in this joint structure 200 can be referred to the working principle of the corresponding component 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 first embodiment described above.

[0151] Specifically, in this embodiment, when the driving member 250 is in the initial position, the driving member 250 is located inside 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 part 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, that is, the third locking member 310 is engaged with the third connecting seat 230 and the fourth connecting seat 290 at the same time.

[0152] When the driving member 250 moves from the initial position to the unlocked position, it drives the first locking member 240 to move in the opposite direction of the axial direction, so that the first locking member 240 moves into the first connecting seat 210 to reach the first unlocking position. During the movement of the driving member 250 in the opposite direction of the axial direction, it gradually stops abutting against the second locking member 280. Under the reset action of the fifth elastic member 340, it can drive the second locking member 280 to move to the second unlocking position to retract from the third connecting seat 230. When the locking part 281 of the second locking member 280 moves in a direction parallel to the opposite direction of the axial direction, the third locking member 310 is no longer abutted by the locking part 281. Under the action of the second elastic member 320, the third locking member 310 can move to the third unlocking position. It should be noted that in this embodiment, the first release position of the first locking member 240 is located inside the first connecting seat 210, the third release position is located inside the third connecting seat 230, and the first traction member 270 of the third locking member 310 passes through the second connecting seat 220 and is installed inside the front wheel frame 120.

[0153] When the drive member 250 moves from the unlocked position to the initial position, it pushes the second locking member 280 to move in the positive axial direction to the second locking position. The locking part 281 passes through the second connecting seat 220 and the third connecting seat 230 and abuts against the third locking member 310, so that the fourth connecting seat 290 and the third connecting seat 230 are relatively fixed, and the third connecting seat 230 and the second connecting seat 220 are also relatively fixed. In addition, after the drive member 250 moves to the initial position, the first locking member 240 is no longer pressed by the drive member 250. Since there is a gap between the drive member 250 and the first locking member 240, under the reset force of the first elastic member 260, the first locking member 240 is driven to move to the first locking position, so that the first connecting seat 210 and the second connecting seat 220 are relatively fixed.

[0154] Referring to Figures 35 to 41, the eleventh embodiment of this application provides a joint structure 200, which can also be regarded as a variation of the joint structure 200 in the first embodiment, the difference being:

[0155] The first connecting seat 210 is provided with a first pushing part 216, which is spaced apart from the first limiting post 211 in the circumferential direction, and the first pushing part 216 can be elastically deformed in the radial direction.

[0156] Referring to Figure 38, when the trolley 1000 is in a folded state, in the circumferential direction, the first pushing part 216 is located between the first limiting post 211 and the third limiting post 231, and the third limiting post 231 is located between the first pushing part 216 and the second limiting post 221. The first pushing part 216 is used to push the third limiting post 231 toward the direction closer to the second limiting post 221.

[0157] Referring to Figure 40, when the trolley 1000 is in the extended state, the third limiting post 231 is located between the first limiting post 211 and the first pushing part 216 in the circumferential direction. That is, the first pushing part 216 and the first limiting post 211 are located on both sides of the third limiting post 231 in the circumferential direction, and the first pushing part 216 and the third limiting post 231 are spaced apart in the circumferential direction. It can be seen that at this time, the third limiting post 231 is located both between the first limiting post 211 and the first pushing part 216, and also between the first limiting post 211 and the second limiting post 221. As shown in Figure 40, when the trolley 1000 is in the extended state, a part of the first pushing part 216 is also simultaneously positioned opposite the second limiting post 221 in a direction parallel to the axial direction.

[0158] Referring to Figures 38 and 40, during the process of the trolley 1000 switching from a folded state to an extended state, the first pushing part 216 abuts against the third limiting post 231 in the opposite direction of the circumference, relative to the first limiting post 211, and pushes the third limiting post 231 to slide towards the side of the movable groove 224 near the second limiting post 221. This allows the handframe 110 to rotate soon after it rotates, driving the rear wheel frame 130 to rotate circumferentially away from the front wheel frame 120. When the third limiting post 231 abuts against the side of the movable groove 224 near the second limiting post 221, the included angle between the rear wheel frame 130 and the front wheel frame 120 is the first included angle α1. At this time, the rear wheel frame 130, the front wheel frame 120, and the supporting surface (such as 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 pushing part 216 can still 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 pushing part 216 will undergo elastic deformation in the radial direction and can move in the opposite circumferential direction to the radially outer side of the third limiting post 231. Then, the first pushing part 216 continues to move until it passes the third limiting post 231 and reaches the side of the third limiting post 231 that is circumferentially away from the first limiting post 211. At this time, the first pushing part 216 returns to its shape in the radial direction before contacting 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 abuts against the third limiting post 231. At this point, the trolley 1000 completes the conversion and is in the extended state.

[0159] As can be seen, this embodiment does not require the first limiting post 211 to push the third limiting post 231 to slide towards the side of the movable groove 224 close to the second limiting post 221, as in the first embodiment, thereby realizing the relative opening of the rear wheel frame 130 and the front wheel frame 120. This embodiment speeds up the unfolding speed of the trolley 1000 and improves the switching rate.

[0160] Referring to Figures 36, 38, and 40, the first pushing part 216 is configured as an elastic arm, the extension direction of which intersects the circumferential direction. Specifically, compared to the first embodiment, the protruding ridge 217 in this embodiment is configured discontinuously along the circumferential direction, that is, the protruding ridge 217 is discontinuously distributed along the circumferential direction. The protruding ridge 217 forms a notch, the first pushing part 216 is located at the notch, and one end of the first pushing part 216 is connected to the edge of the notch on one side in the circumferential direction, while the other end of the first pushing part 216 is disconnected from the edge of the notch on the other side in the circumferential direction, and extends inward toward the area enclosed by the protruding ridge 217 to push against the third limiting post 231. When the trolley 1000 is converted from a folded state to an extended state, the first pushing part 216 can deform radially toward the corresponding notch to move to the radially outer side of the third limiting post 231.

[0161] Referring to Figures 38 and 39, the third limiting post 231 has an abutment surface 2311 on the side near the first limiting post 211. This abutment surface 2311 is located on the path of the first pushing part 216 moving in the opposite direction of the circumference, so that when the first pushing part 216 moves relative to the third limiting post 231 in the opposite direction of the circumference, it can effectively abut against the side of the third limiting post 231 near the first limiting post 211, so as to push the third limiting post 231 together in the opposite direction of the circumference. When the first pushing part 216 abuts against the abutment surface 2311, the angle between the extension direction of the abutment surface 2311 and the extension direction of the first pushing part 216 is between 65° and 75°, so that when the first pushing part 216 pushes against the third limiting post 231 in the opposite direction of the circumference, it is not easy to move to the radial outer side of the third limiting post 231.

[0162] 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 pushing part 216. This ensures that the first pushing part 216 will not come into contact with the second limiting post 221 when moving circumferentially, and can pivot relative to the second limiting post 221 at any angle. Referring to Figure 40, when the trolley 1000 is in the extended state, the first pushing part 216 can also be completely offset from the second limiting post 221 in a direction parallel to the axial direction. That is, the first pushing part 216 can be completely located on the side of the second limiting post 221 away from the third limiting post 231, instead of, as shown in Figure 40, where a part of the first pushing part 216 is also opposite to the second limiting post 221 in a direction parallel to the axial direction. Specifically, the first pushing part 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 length of the first pushing part 216 extending in the direction parallel to the axial direction, that is, the length of the first pushing part 216 extending 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 the direction parallel to the axial direction. This can be understood as the plane containing the end face of the first pushing part 216 toward the second connecting seat 220 and the plane containing the end face of the second limiting post 221 toward the end face of the first connecting seat 210 being spaced apart or exactly flush in a direction parallel to the axial direction. Therefore, during the process of the trolley 1000 switching from a folded state to an extended state, the second limiting post 221 will not obstruct the circumferential rotation of the first pushing part 216.

[0163] Referring to Figures 35 and 36, in the joint structure 200 provided in this embodiment, the first connecting seat 210 does not have a first engaging member 215, and the second connecting seat 220 does not have a second engaging member 225. However, in other embodiments, the first connecting seat 210 in the eleventh embodiment may also have a first engaging member 215, and the second connecting seat 220 may also have a second engaging member 225.

[0164] Referring to Figures 35, 36, and 38, the first connecting seat 210 is further provided with a fourth limiting post 218. The fourth limiting post 218 extends toward the second connecting seat 220 in a direction parallel to the axial direction and is spaced apart from the first limiting post 211 in the circumferential direction. 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 ensures that the fourth limiting post 218 will not circumferentially abut against the second limiting post 221 and can pivot relative to the second limiting post 221 at any angle. In this embodiment, the first limiting post 211 and the fourth limiting post 218 are arranged radially opposite each other.

[0165] 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. In a preferred embodiment, the fourth limiting post 218 extends in a direction parallel to the axial direction. Specifically, the fourth limiting post 218 also protrudes from the bottom wall of the first accommodating space 212 within the first connecting seat 210 toward the second connecting seat 220.

[0166] Specifically, the length of the fourth limiting post 218 extending in the direction parallel to the axial direction, that is, the length of the fourth limiting post 218 extending towards 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 the direction parallel to the axial direction. This can be understood as the plane containing the end face of the fourth limiting post 218 facing the second connecting seat 220 and the plane containing the end face of the second limiting post 221 facing the first connecting seat 210 being spaced apart or exactly flush in the direction parallel to the axial direction. Therefore, during the switching between the folded and extended states of the trolley 1000, the second limiting post 221 will not obstruct the circumferential rotation of the fourth limiting post 218.

[0167] Referring to Figure 40, when the trolley 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 in the positive direction of the circumferential direction to move the third limiting post 231 away from the second limiting post 221. In the illustrated embodiment, the fourth limiting post 218 is positioned further away from the third limiting post 231 than the second limiting post 221, and the fourth limiting post 218 is completely offset from the second limiting post 221 in a direction parallel to the axial direction. That is, in the circumferential direction, the fourth limiting post 218 and the first limiting post 211 are located on opposite sides of the second limiting post 221. Therefore, when the fourth limiting post 218 moves in the positive circumferential direction, it needs to pass the second limiting post 221 first before it can push the third limiting post 231 away from the second limiting post 221.

[0168] Referring to Figure 38, when the trolley 1000 is in the folded state, the third limiting post 231 is still located between the first limiting post 211 and the fourth limiting post 218 in the circumferential direction, and the third limiting post 231 is still located between the first limiting post 211 and the second limiting post 221 in the circumferential direction. However, at this time, the fourth limiting post 218 is 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.

[0169] Referring to Figures 38 and 40, during the transition of the trolley 1000 from its extended state to its folded state, the fourth limiting post 218 moves towards the third limiting post 231 in the positive circumferential direction. 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 against the side of the third limiting post 231 away from the first limiting post 211 in the circumferential direction. As the fourth limiting post 218 continues to move in the positive circumferential direction, it pushes the third limiting post 231 within the movable groove 224 towards the groove wall away from the second limiting post 221, until the third limiting post 231 abuts against the groove wall of the movable groove 224 away from the second limiting post 221 in the positive circumferential direction. At this point, 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 on the side away from the second limiting post 221. Thus, the trolley 1000 completes the conversion and is in a folded state.

[0170] In this embodiment, regardless of whether the trolley 1000 is in an extended or 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.

[0171] Compared to the first embodiment, the illustrated embodiment, in addition to the method of the rider frame 110 pushing the rear wheel frame 130 together to move closer to the front wheel frame 120, causing the third limiting post 231 to move toward the side of the movable groove 224 away from the second limiting post 221, also uses the fourth limiting post 218 to push the third limiting post 231, causing the third limiting post 231 to move toward the side of the movable groove 224 away from the second limiting post 221.

[0172] Referring to Figures 36, 38, and 40, the first pushing part 216 is also located circumferentially between the first limiting post 211 and the fourth limiting post 218. Furthermore, the circumferential distance between the first pushing part 216 and the fourth limiting post 218 is greater than or equal to the maximum circumferential width of the third limiting post 231.

[0173] When the trolley 1000 is in the extended state, referring to Figure 40, both the first pushing part 216 and the third limiting post 231 are located between the first limiting post 211 and the fourth limiting post 218 in the circumferential direction. The third limiting post 231 is located between the first limiting post 211 and the first pushing part 216 in the circumferential direction, and the fourth limiting post 218 is located further away from the third limiting post 231 in the circumferential direction than the first pushing part 216.

[0174] During the transition of the trolley 1000 from its extended to its folded state, as the first pushing part 216 moves in the positive circumferential direction, it will pass the second limiting post 221 before the fourth limiting post 218 to contact the third limiting post 231. The first pushing part 216 undergoes elastic deformation in the radial direction and moves to the radially outer side of the third limiting post 231. Subsequently, the first pushing part 216 continues to move to the side of the third limiting post 231 closest to the first limiting post 211 in the circumferential direction, and at this position, 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 pushing part 216 are respectively located on either side of the third limiting post 231 in the circumferential direction. Specifically, the end of the first pushing part 216 that is not connected to the protruding part 217 and the fourth limiting post 218 are respectively located on both sides of the third limiting post 231 in the circumferential direction. That is, in the circumferential direction, the third limiting post 231 is located between the first pushing part 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 will push 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 trolley 1000 completes the conversion and reaches the folded state.

[0175] Referring to Figures 39 and 40, the third limiting post 231 has a pressing surface 2312 on the side near the second limiting post 221. The pressing surface 2312 is located on the trajectory of the first pushing part 216 moving in the positive circumferential direction, so that the first pushing part 216 can effectively contact the pressing surface 2312 in the positive circumferential direction. When the first pushing part 216 contacts the pressing surface 2312, the extension direction of the pressing surface 2312 is approximately parallel to the extension direction of the first pushing part 216, for example, the included angle between the two is between 0° and 25°. This ensures that when the first pushing part 216 contacts the third limiting post 231 in the positive circumferential direction, there will be no excessive resistance, so that it can smoothly move in the positive circumferential direction to the radial outer side of the third limiting post 231.

[0176] Since the second limiting post 221 is located on one side of the circumferential movement trajectory of the fourth limiting post 218 and also on one side of the circumferential movement trajectory of the first pushing part 216 in a direction parallel to the axial direction, this allows the fourth limiting post 218 and the first pushing part 216 to both pass over the second limiting post 221 when moving in the opposite circumferential direction during the process of the trolley 1000 switching from a folded state to an extended state. This allows the third limiting post 231 to abut against the second limiting post 221 in the opposite circumferential direction. The limiting post 231 can smoothly stop against the second limiting post 221 under the push of the first pushing part 216 in the opposite direction of the circumference, and will not stop moving prematurely due to the contact between the fourth limiting post 218 and the second limiting post 221 in the opposite direction of the circumference. At the same time, the first limiting post 211 can also move smoothly in the opposite direction of the circumference until it stops against the third limiting post 231, and will not stop moving prematurely due to the contact between the first pushing part 216 and the second limiting post 221 in the opposite direction of the circumference.

[0177] Referring to Figures 35 and 41, the trolley 1000 is equipped with a third traction member 180. One end of the third traction member 180 is connected to the first pusher frame 111, and the other end is connected to the seat 170. Preferably, the third traction member 180 is a fabric strap. When the first pusher frame 111 is unfolded relative to the second pusher frame 112, the seat 170 rotates clockwise under the traction of the third traction member 180, that is, it pivots circumferentially toward the side away from the rear wheel frame 130.

[0178] Referring to Figures 35, 37, and 41, in this embodiment, the fourth connecting seat 290 is provided with a second pushing part 294. The second pushing part 294 is located on the side of the fourth connecting seat 290 facing the third connecting seat 230. The second pushing part 294 is columnar and extends into the third connecting seat 230 in a direction parallel to the axial direction. The second connecting seat 220 is also provided with a third pushing part 227. The third pushing part 227 is located on the side of the second connecting seat 220 away from the first connecting seat 210 and extends into the third connecting seat 230 in a direction parallel to the axial direction. The second pushing part 294 and the third pushing part 227 are arranged opposite each other in the circumferential direction, and the third pushing part 227 is located in front of the second pushing part 294 in 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 part 294 and the third pushing part 227. The limiting groove 236 extends 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 part 294 and the third pushing part 227 to move circumferentially.

[0179] It should be noted that the second pushing portion 294 extends toward the third connecting seat 230 and is spaced apart axially; specifically, the second pushing 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 pushing portion 227 extends toward the third connecting seat 230 and is spaced apart axially; specifically, the third pushing portion 227 protrudes from the surface of the second connecting seat 220 facing the third connecting seat 230 toward the third connecting seat 230. The second pushing portion 294 and the third pushing portion 227 extending in a direction parallel to the axial direction are preferred embodiments.

[0180] When the seat 170 pivots circumferentially away from the rear wheel frame 130, the second push part 294 of the seat 170 pushes the third push part 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 trolley 1000 more quickly.

[0181] When the third pushing part 227 moves along the direction of the seat 170 away from the rear wheel frame 130 until it abuts against the end of the limiting groove 236 near the third pushing part 227 in the circumferential direction, the included angle between the front wheel frame 120 and the rear wheel frame 130 is exactly the first included angle α1. When the second pushing part 294 moves along the direction of the seat 170 near the rear wheel frame 130 and abuts against the end of the limiting groove 236 near the second pushing part 294 in the circumferential direction, the included angle between the seat 170 and the rear wheel frame 130 is exactly the included angle between the two when the trolley 1000 is in the folded state. That is, the two ends of the limiting groove 236 in the circumferential direction respectively limit the rotational travel of the second pushing part 294 and the third pushing part 227.

[0182] The process of switching the trolley 1000 from a folded state to an extended state includes a first stage and a second stage. In the first stage, the handlebar 110 rotates circumferentially away from the front wheel frame 120, and the handlebar 110 drives the rear wheel frame 130 to rotate circumferentially away from the front wheel frame 120. In the second stage, the first push handlebar 111 unfolds relative to the second push handlebar 112, and the first push handlebar 111 drives the seat 170 to rotate circumferentially away from the rear wheel frame 130 via the third traction member 180, and the seat 170 drives the front wheel frame 120 to rotate circumferentially away from the rear wheel frame 130.

[0183] Referring to Figures 35, 37, and 41, a guide portion 237 is provided on the side of the third connecting seat 230 facing the fourth connecting seat 290. This guide portion 237 extends circumferentially around the axial direction and protrudes towards 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 towards the fourth connecting seat 290. The second locking member 280 and the third locking member 310 are both fitted radially outside the guide portion 237, which guides the second locking member 280 and the third locking member 310 to move axially. The guide portion 237 is provided with a plurality of guide grooves 238, which are recessed from the circumferential surface of the guide portion 237 toward the axial direction. The guide grooves 238 are spaced apart circumferentially. The guide grooves 238 are used to receive a plurality of engaging portions 283 in a direction parallel to the axial direction, so as to guide the corresponding engaging portions 283 to move in a direction parallel to the axial direction and to restrict the engaging portions 283 from rotating circumferentially, thereby restricting the second locking member 280 from rotating around the axial direction. In other embodiments, only one engaging portion 283 and one guide groove 238 may be provided.

[0184] It should be noted that the terms “first,” “second,” “third,” “fourth,” “fifth,” etc., used in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0185] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0186] The above embodiments merely illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0187] 1000: Stroller 100: Frame 110: Rider's frame 111: The First Pushing Frame 1111: First support rod 1112: Push Handle 112: Second Pusher 1121: Second support rod 113: Adduction joint 1131: Fifth Connector 11311: Movable hole 1132: Sixth Connector 11321: Lock slot 11322: Limiting recess 1133: Fourth locking component 1134: Fifth Locking Component 11341: Sliding Inclined Plane 1135: Limiting cover 1136: Third elastic element 1137: Second Pivot 120: Front wheel frame 121: Front strut 122: Front crossbar 130: Rear wheel frame 131: Rear member 132: Rear crossbar 141: Front wheel seat 142: Rear wheel seat 151: Front wheel 152: Rear wheel 161: Release button 1611: Drive wheel 1612: Operations Department 162: Second traction component 163: Fourth elastic element 164: Safety push button 170: Seat 171: Seat board 172: Folding shoulder straps 1721: Knot 173: Receiving and Collecting Mechanism 1731: Rolls 17311: Opening 1732: Coil Spring 1733: Cover 17331: Main Cover 17332: Accessory operculum 1734: Guide Wheel 1735: Steering Wheel 1736: Guide Rib 180: Traction component 200: Joint Structure 210: First connecting seat 211: First limiting post 212: First Accommodation Space 213: First locking slot 214: Top Pushing Section 215: First Card Assembly 2151: Flexible Arm 2152: Deformation section 2153:convex hull 216: First Pushing Section 217: Protruding ridge 218: Fourth Limiting Post 220: Second connecting seat 221: Second limiting post 222: Second Accommodation Space 223: Second locking slot 224: Activity Slot 225: Second Card Assembly 2251: Inner wall 2252:Outer wall 2253: First sidewall 2254: Second sidewall 2255: Card-connecting section 2256: Guiding slope 226: First blocking section 227: Third Pushing Section 230: Third Connector 231: Third limiting post 2311: Contact surface 2312: Press-fit surface 232: Third Accommodation Space 233: Third Locking Slot 234: Second blocking section 235: Third Block 236: Limiting groove 237: Guiding section 238: Guide groove 240: First locking component 250: Drive unit 251:Butt part 260: First elastic element 270: First traction component 280: Second locking element 281: Locking part 282: Main body 283: Connector 290: Fourth Connector 291: Fourth Accommodation Space 292: Fourth Locking Slot 293: Fourth Block 294: Second Pushing Section 310: Third locking component 320: Second elastic element 330: Rotating seat 340: Fifth elastic element F1: First Direction U1-U1, U2-U2, U3-U3, U4-U4, U5-U5: Lines α1: First included angle α2: Second included angle α3: Third included angle α4: Fourth included angle α5: Fifth included angle

Claims

1. A joint structure, comprising: A first connecting seat, a second connecting seat, and a 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. 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. The first limiting post, the third limiting post, and the second limiting post are arranged sequentially in the circumferential direction. A first locking member is movably disposed between the first connecting seat and the second connecting seat and has a first locking position and a first unlocking position. It 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 unlocking position, both the first connecting seat and the third connecting seat can pivot relative to the second connecting seat.

2. The joint structure as described in claim 1, wherein, The first limiting post protrudes toward the second connecting seat, the second limiting post protrudes toward the first connecting seat, and the third limiting post protrudes toward the first connecting seat and passes through the second connecting seat. The second connecting seat is provided with a movable groove for the third limiting post to move along the circumferential direction. The first limiting post and the third limiting post can move circumferentially within the second connecting seat.

3. The joint structure as described in claim 1, wherein, The first locking element is located radially outside the first limiting post, the second limiting post, and the third limiting post.

4. The joint structure as described in claim 1, wherein, The joint structure further includes a driving member, which is movably disposed between the first connecting seat and the second connecting seat, and has an initial position and an unlocked position. When the driving member moves from the initial position to the unlocked position, the driving member drives the first locking member to move from the first locking position to the first unlocking position. The driving member and the first locking member are arranged adjacent to each other along the axial direction. The driving member and the first locking member are both located radially outside the first limiting post, the second limiting post and the third limiting post.

5. The joint structure as described in claim 1, wherein, The joint structure further includes a second locking member, which is movably disposed in the joint structure and has at least one locking part. The locking part is spaced apart from the axial direction. The second locking member has a second locking position and a second unlocking 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 part passes through the third connecting seat and the second connecting seat. When the first locking member is in the first unlocking position, the second locking member is in the second unlocking position. The at least one locking part passes through only the third connecting seat or the second connecting seat.

6. The joint structure as described in claim 5, wherein, 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 trolley, comprising: A trolley frame, a front wheel frame, a rear wheel frame, and a joint structure as claimed in any one of claims 1 to 6, wherein the trolley frame is connected to a first connecting seat, the front wheel frame is connected to a second connecting seat, and the rear wheel frame is connected to a third connecting seat; the trolley frame, the front wheel frame, and the rear wheel frame are pivotally connected to each other via the joint structure to allow the trolley to switch between an extended state and a folded state; the rear wheel frame is located circumferentially between the front wheel frame and the trolley frame; when the trolley is in the extended state, the first locking member is in the first locked position, and the trolley frame, the front wheel frame, and the rear wheel frame are circumferentially spaced apart; when the trolley is in the folded state, the trolley 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 as described in claim 7, wherein, When the trolley is in the folded state, the first limiting post, the third limiting post, and the second limiting post are spaced apart circumferentially.

9. The cart as described in claim 7, wherein, The first limiting post protrudes towards the second connecting seat, the second limiting post protrudes towards the first connecting seat, and the third limiting post protrudes towards the first connecting seat and passes through the second connecting seat. The second connecting seat is provided with a movable groove for the third limiting post to move circumferentially. The first limiting post and the third limiting post can move circumferentially within the second connecting seat. When the trolley is in the folded state, the third limiting post abuts against the groove wall on the side of the movable groove away from the second limiting post.

10. The trolley as described in 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 the side of the first limiting post and the second limiting post away from the third limiting post along the circumferential direction. When the trolley is in the folded state, the first engaging member abuts against the second engaging member on the side of the second engaging member closer to the second limiting post.

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