Improved trolley

Abstract

The utility model provides a kind of improved trolley, including front wheel support, rear wheel support, underframe and handrail, underframe and handrail are rotatably connected between front wheel support and rear wheel support respectively;Connecting rod structure, connecting rod structure includes first connecting rod and connecting rod assembly, first connecting rod one end is hinged with underframe and / or handrail, connecting rod assembly is used to drive first connecting rod movement, to make underframe and / or handrail synchronous rotation relative to front wheel support and rear wheel support, and drive front wheel support and rear wheel support close folding.Compared with prior art, through connecting rod structure drive underframe and handrail synchronous rotation, drive front wheel support and rear wheel support close folding, with the advantages of simple structure, convenient operation and synchronous folding can be realized.

Description

Technical Field

[0001] This utility model relates to the field of trolley technology, and in particular to an improved handcart. Background Technology

[0002] There are many types of outdoor strollers in the current technology. Most of them have fixed structures for the armrests and leg tubes, which occupy a lot of space when not in use. In the folding process, the existing technology is relatively complicated and cannot be folded easily and quickly.

[0003] Chinese Patent Publication No. CN110356448B, published in October 2019, discloses a handcart, specifically comprising two side frames arranged side by side, and multiple support members connecting the two side frames. Each side frame includes a synchronous vertical rod and front and rear leg components distributed on both sides of the synchronous vertical rod. In the folded state, the front and rear leg components move closer to the synchronous vertical rod, and in the unfolded state, the front and rear leg components unfold accordingly. The support members include a first connector connecting the front leg components of the two side frames, and a second connector connecting the rear leg components of the two side frames. A locking mechanism is provided between the first and second connectors to limit their relative position to maintain the unfolded state, and the locking mechanism also has an unlocking state that allows the first and second connectors to move closer to each other. Although the above patent can achieve folding or unfolding, its folding or unfolding structure is relatively complex and lacks an effective linkage design, resulting in asynchronous movements of various components during folding, affecting the folding effect and user experience.

[0004] Therefore, further improvements are necessary. Utility Model Content

[0005] Based on this, the purpose of this utility model is to provide an improved handcart to overcome the shortcomings of the prior art. The base frame and the handrail frame can be folded synchronously through a linkage structure, making operation simple and convenient and improving the user's operating experience.

[0006] An improved handcart designed for this purpose includes: A front wheel bracket, a rear wheel bracket, a base frame, and a handrail frame, wherein the base frame and the handrail frame are rotatably connected between the front wheel bracket and the rear wheel bracket, respectively; A linkage structure, comprising a first link and a link assembly, wherein one end of the first link is hinged to the base frame and / or the handrail frame, and the link assembly is used to drive the first link to move so that the base frame and / or the handrail frame rotate synchronously relative to the front wheel bracket and the rear wheel bracket, and drive the front wheel bracket and the rear wheel bracket to move closer together and fold down.

[0007] The linkage structure also includes a second linkage. One end of the first linkage is hinged to the base frame, and one end of the second linkage is hinged to the handrail frame. The first linkage and the second linkage are hinged to each other to form a linkage structure. The linkage between the first linkage and the second linkage drives the base frame and the handrail frame to rotate, fold or unfold synchronously.

[0008] The linkage assembly also includes a sliding rod that can slide along the length of the front wheel bracket and the rear wheel bracket. The sliding rod is hinged to the first link and the second link respectively. The sliding of the sliding rod causes the first link and the second link to rotate, so as to realize the folding or unfolding of the base frame and the handrail frame.

[0009] The linkage assembly further includes a connector disposed between the first linkage and the sliding rod. One end of the connector is hinged to the first linkage, and the other end of the connector is hinged to the sliding rod. The sliding rod drives the first linkage through the connector to realize the folding or unfolding of the base frame.

[0010] The front wheel bracket and the rear wheel bracket are respectively provided with guide structures between themselves and the sliding rod. The guide structure includes a guide portion disposed on one side of the sliding rod and a guide groove disposed on one side wall of the front wheel bracket and the rear wheel bracket. The sliding rod protrudes outward along the sliding direction, and the sliding rod engages with the guide groove through the guide portion.

[0011] The handrail includes a first support and at least one pair of first and second tubes. One end of each of the first and second tubes is hinged to the first support. A synchronization structure is provided between the second tube and the first support. The synchronization structure includes a linkage rod and a slot. The slot is provided on the first support. One end of the linkage rod is hinged to one end of the second tube. The other end of the linkage rod is movable on the slot via a connector. When the second tube is folded, the linkage rod is positioned at a first position in the slot via the connector. When the second tube is unfolded, the linkage rod is positioned at a second position in the slot via the connector.

[0012] The handcart also includes a drive structure, which is disposed on any one of the front wheel bracket, the rear wheel bracket, the base frame, or the handrail frame; wherein, the linkage assembly is driven by the drive structure to drive the base frame and / or the handrail frame to rotate.

[0013] The drive structure includes a push handle that can be mounted on the front wheel bracket or the rear wheel bracket. A fourth link is provided between the sliding rod and the push handle, and the sliding rod is driven to slide through the fourth link when the push handle rotates.

[0014] At least two chassis are provided, and the at least two chassis are symmetrically arranged between the front wheel bracket and the rear wheel bracket. The drive structure includes a rotating joint provided on one end of the two chassis, a joint tooth that engages with the tooth on the rotating joint, and an unlocking component that controls the axial movement of the joint tooth. The chassis is provided with a plurality of spaced support members. The unlocking component includes a traction member and a pull handle that drives the traction member to move. The front and rear ends of the traction member are connected to the joint tooth, and the pull handle is provided on the support member.

[0015] An elastic reset member is provided between the rotating joint and the joint tooth. By driving the pull handle, the joint tooth is displaced, so that the joint tooth engages with the tooth on the rotating joint and squeezes the elastic reset member, thereby causing the two base frames to rotate relative to each other.

[0016] Compared with the prior art, the improved handcart in the above embodiment drives the base frame and handrail frame to rotate synchronously through a linkage structure, which drives the front wheel bracket and rear wheel bracket to fold together. It has the advantages of simple structure, convenient operation and synchronous folding. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the handcart in one embodiment of the present invention.

[0020] Figure 2 This is an exploded view of a handcart in one embodiment of the present invention.

[0021] Figure 3 This is a cross-sectional view of the unfolded structure of a handcart in one embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the driving structure in one embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of a push handle as the driving structure in another embodiment of the present invention.

[0024] Figures 6-8 These are schematic diagrams showing the changes in the folding state of a handcart in one embodiment of this utility model.

[0025] Figure 9 This is a schematic diagram of the handcart in a folded state according to one embodiment of the present invention. Detailed Implementation

[0026] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model 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 utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0027] like Figures 1-9 As shown, an improved handcart is provided, including The front wheel bracket 1, the rear wheel bracket 2, the base frame 3, and the handrail frame 4 are rotatably connected between the front wheel bracket 1 and the rear wheel bracket 2, respectively. The linkage structure 5 includes a first link 51 and a linkage assembly 53. One end of the first link 51 is hinged to the base frame 3 and / or the handrail frame 4. The linkage assembly 53 is used to drive the first link 51 to move so that the base frame 3 and / or the handrail frame 4 rotate synchronously relative to the front wheel bracket 1 and the rear wheel bracket 2, and drive the front wheel bracket 1 and the rear wheel bracket 2 to move closer together and fold.

[0028] Specifically, when the linkage assembly 53 drives the first linkage 51 to rotate around the hinge point, the base frame 3 or the handrail frame 4 rotates around the pivot under the traction of the first linkage 51. Since the base frame 3 and the handrail frame 4 are respectively connected to the front wheel bracket 1 and the rear wheel bracket 2, during their opposite rotation, they will drive the front and rear wheel brackets to move closer together and fold, thereby achieving a compact folding of the overall structure of the handcart.

[0029] Furthermore, the linkage structure 5 also includes a second linkage 52. One end of the first linkage 51 is hinged to the base frame 3, and one end of the second linkage 52 is hinged to the handrail frame 4. The first linkage 51 and the second linkage 52 are hinged to each other to form a linkage structure. The linkage between the first linkage 51 and the second linkage 52 drives the base frame 3 and the handrail frame 4 to rotate, fold or unfold synchronously.

[0030] Specifically, when the trolley needs to be folded, the first link 51 and the second link 52 transmit motion through the hinge point. The rotation of the base frame 3 drives the second link 52 to rotate around the hinge point through the first link 51, which in turn drives the armrest frame 4 to rotate in the opposite direction. The coordinated movement of the base frame 3 and the armrest frame 4 is achieved through mechanical linkage, making the folding process smoother and more efficient.

[0031] Furthermore, such as Figures 1-3 As shown, the linkage assembly 53 also includes a sliding rod 531, which can slide along the length of the front wheel bracket 1 and the rear wheel bracket 2. The sliding rod 531 is hinged to the first link 51 and the second link 52 respectively. The sliding of the sliding rod 531 drives the first link 51 and the second link 52 to rotate, so as to realize the folding or unfolding of the base frame 3 and the handrail frame 4.

[0032] Specifically, when the sliding rod 531 is driven by an external force to slide along the length of the front wheel bracket 1 and the rear wheel bracket 2, the linear displacement of the sliding rod 531 is transmitted to the first link 51 and the second link 52 through the hinge point, forcing them to rotate around the hinge axis. The rotation of the first link 51 causes the base frame 3 to fold relative to the front wheel bracket 1 and the rear wheel bracket 2, and the rotation of the second link 52 synchronously drives the handrail frame 4 to fold. Due to the linkage between the sliding rod 531 and the two links, the folding action of the base frame 3 and the handrail frame 4 can be kept synchronous, avoiding mechanical interference or structural deformation caused by asynchrony.

[0033] Furthermore, such as Figures 1-3 As shown, the linkage assembly 53 also includes a connector 532, which is disposed between the first link 51 and the sliding rod 531. One end of the connector 532 is hinged to the first link 51, and the other end of the connector 532 is hinged to the sliding rod 531. The sliding rod 531 drives the first link 51 through the connector 532 to realize the folding or unfolding of the base frame 3.

[0034] Specifically, the connecting member 532 functions to convert the linear motion of the sliding rod into the rotational motion of the first connecting rod 51. When the sliding rod 531 slides along the length of the front wheel bracket 1 and the rear wheel bracket 2 under the action of external force, the hinge point between the connecting member 532 and the sliding rod 531 is displaced. Since the other end of the connecting member 532 is hinged to the first connecting rod 51, the linear motion of the sliding rod 531 is converted into the rotational motion of the first connecting rod 51 around the hinge point of the base frame 3 through the connecting member 532. When the first connecting rod 51 rotates, the base frame 3 rotates synchronously around the connection point with the front wheel bracket 1 or the rear wheel bracket 2, thereby realizing the folding or unfolding action. In this process, the connecting member 532, as a motion conversion mechanism, effectively coordinates the cooperation between the linear motion of the sliding rod 531 and the rotational motion of the base frame 3.

[0035] Furthermore, such as Figures 1-3As shown, the front wheel bracket 1 and the rear wheel bracket 2 are respectively provided with guide structures between them and the sliding rod 531. The guide structure includes a guide part 5311 provided on one side of the sliding rod 531 and a guide groove 21 provided on one side wall of the front wheel bracket 1 and the rear wheel bracket 2. The guide part 5311 protrudes outward along the sliding direction of the sliding rod 531, and the sliding rod 531 cooperates with the guide groove 21 through the guide part 5311.

[0036] Specifically, when the sliding rod 531 is driven by an external force, its side guide portion 5311 is embedded in the guide groove 21 of the front wheel bracket 1 and the rear wheel bracket 2, and slides linearly along the length of the groove 21. Due to the constraint of the cooperation between the guide portion 5311 and the guide groove 21, the sliding rod 531 cannot be laterally offset or rotated, and can only move smoothly along the preset folding direction. This linear motion is converted into the rotation of the base frame 3 and the handrail frame 4 through the linkage assembly 53, so that the front wheel bracket 1 and the rear wheel bracket 2 gradually come together to complete the folding process. When unfolded, the sliding rod 531 slides in the opposite direction, the guide portion 5311 is reset in the guide groove 21, and the components are driven to return to the unfolded state.

[0037] Furthermore, such as Figure 2 and Figure 3 As shown, the handrail frame 4 includes a first support 43 and at least one pair of first tubes 41 and second tubes 42. One end of the first tube 41 and the second tube 42 are respectively hinged to the first support 43. A synchronization structure is provided between the second tube 42 and the first support 43. The synchronization structure includes a linkage rod 44 and a slot 431. The slot 431 is provided on the first support 43. One end of the linkage rod 44 is hinged to one end of the second tube 42. The other end of the linkage rod 44 is movable on the slot 431 through a connector. When the second tube 42 is folded, the linkage rod 44 is positioned in the first position of the slot 431 through the connector. When the second tube 42 is unfolded, the linkage rod 44 is positioned in the second position of the slot 431 through the connector.

[0038] Specifically, the adapter refers to the movable part connecting the linkage rod 44 and the slot 431. It can be implemented using a slider or pin structure with rollers. Its function is to convert the rotation of the linkage rod 44 into linear displacement along the slot 431, thereby achieving positioning of the second tube 42 at different positions. When the second tube 42 rotates around the first support 43 to the folded state under the push of the third link 533, the linkage rod 44 drives the adapter to move along the slot 431 to the first position, and forms an angle restriction and positioning on the second tube 42 at this position, keeping it in the folded state. When the second tube 42 rotates outward to the unfolded state under the reverse action of the third link 533, the linkage rod 44 drives the adapter to move to the second position of the slot 431. At this time, the linkage rod 44 and the second tube 42 form an unfolded angle positioning, and the second tube 42 is locked by the limiting characteristics of the slot 431 itself. The entire positioning process does not require an additional locking structure and can be completed by the cooperation of the linkage rod 44 and the adapter.

[0039] Furthermore, such as Figures 1-3 As shown, the handcart also includes a drive structure 6, which is mounted on any one of the front wheel bracket 1, the rear wheel bracket 2, the base frame 3, or the handrail frame 4; wherein, the linkage assembly 53 is driven by the drive structure 6 to drive the base frame 3 and / or the handrail frame 4 to rotate.

[0040] Specifically, the drive structure 6 can be a manual push handle, a pull handle mechanism, a rotatable control lever, an electric button assembly, or other actuators with drive functions. Its output end is connected to the sliding rod 531 or the connecting piece 532 in the linkage assembly 53, and is used to drive the sliding rod 531 to slide along the length direction of the front wheel bracket 1 and the rear wheel bracket 2. When the drive structure 6 is activated, the sliding rod 531 generates a linear displacement, and forms a linkage through the first link 51 and the second link 52 that are hinged to it. The drive base frame 3 and the handrail frame 4 fold or unfold synchronously relative to the front wheel bracket 1 and the rear wheel bracket 2, respectively.

[0041] Furthermore, such as Figure 5 As shown, in other embodiments, the drive structure 6 includes a push handle that can be mounted on the front wheel bracket 1 or the rear wheel bracket 2. A fourth link 7 is hinged between the sliding rod 531 and the push handle. When the push handle rotates, the sliding rod 531 is driven to slide through the fourth link 7.

[0042] Specifically, when the user rotates the push handle, the push handle causes the fourth link 7 to change angle, which in turn drives the sliding rod 531 to slide along the length direction between the front wheel bracket 1 and the rear wheel bracket 2; the sliding of the sliding rod 531 further drives the first link 51 and the second link 52 in the link assembly 53 to rotate, so as to realize the synchronous folding or unfolding operation of the base frame 3 and the handrail frame 4.

[0043] Furthermore, such as Figures 1-4 As shown, at least two base frames 3 are provided, and at least two base frames 3 are symmetrically arranged between the front wheel bracket 1 and the rear wheel bracket 2. The drive structure 6 includes a rotating joint 61 provided on one end of the two base frames 3, a joint tooth 62 that engages with the teeth on the rotating joint 61, and an unlocking component that controls the axial movement of the joint tooth 62. The base frame 3 is provided with a number of spaced support members 31. The unlocking component includes a traction member 63 and a pull handle 64 that drives the traction member 63 to move. The front and rear ends of the traction member 63 are connected to the joint tooth 62, and the pull handle 64 is provided on the support member 31. An elastic reset element is provided between the rotating joint 61 and the joint tooth 62. By driving the pull handle 64, the joint tooth 62 is moved, so that the joint tooth 62 engages with the tooth on the rotating joint 61 and squeezes the elastic reset element, thereby causing the two base frames 3 to rotate relative to each other.

[0044] Specifically, the traction member 63 converts the manual operation of the drive handle 64 into the axial movement of the articulated teeth 62. When the user pulls the handle 64 upward or outward, the traction member 63 is driven to move axially, thereby causing the two articulated teeth 62 to move axially at the same time, so that their teeth engage with the corresponding rotating joints 61, and at the same time compress the elastic reset member. In this state, the rotating joints 61 at both ends of the base frame 3 form a locked connection with the articulated teeth 62, thereby causing the two base frames 3 to rotate synchronously around their connection point, realizing the symmetrical folding or unfolding operation of the base frame.

[0045] Preferred, the traction component 63 is a steel wire rope.

[0046] Furthermore, the top and bottom of the front wheel bracket 1 and the rear wheel bracket 2 are provided with fixed seats for hinged connection of the base frame 3 and the handrail frame 4.

[0047] Furthermore, both the front wheel bracket 1 and the rear wheel bracket 2 are equipped with casters at the bottom.

[0048] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0050] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0051] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0052] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0053] It should also be understood that, in interpreting the connection or positional relationships of components, although not explicitly described, connection and positional relationships are interpreted to include a range of error, which should be within the acceptable deviation range of a specific value as determined by a person skilled in the art. For example, "approximately," "about," or "substantially" can mean within one or more standard deviations, without limitation herein.

[0054] 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.

[0055] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An improved handcart, characterized in that: include A front wheel bracket (1), a rear wheel bracket (2), a base frame (3), and a handrail frame (4), wherein the base frame (3) and the handrail frame (4) are rotatably connected between the front wheel bracket (1) and the rear wheel bracket (2), respectively; The linkage structure (5) includes a first link (51) and a link assembly (53). One end of the first link (51) is hinged to the base frame (3) and / or the handrail frame (4). The link assembly (53) is used to drive the first link (51) to move so that the base frame (3) and / or the handrail frame (4) rotate synchronously relative to the front wheel bracket (1) and the rear wheel bracket (2), and drive the front wheel bracket (1) and the rear wheel bracket (2) to close and fold together.

2. The improved handcart according to claim 1, characterized in that: The linkage structure (5) further includes a second linkage (52). One end of the first linkage (51) is hinged to the base frame (3), and one end of the second linkage (52) is hinged to the handrail frame (4). The first linkage (51) and the second linkage (52) are hinged to each other to form a linkage structure. The linkage between the first linkage (51) and the second linkage (52) drives the base frame (3) and the handrail frame (4) to rotate, fold or unfold synchronously.

3. The improved handcart according to claim 2, characterized in that: The linkage assembly (53) further includes a sliding rod (531), which can slide along the length direction of the front wheel bracket (1) and the rear wheel bracket (2). The sliding rod (531) is hinged to the first link (51) and the second link (52) respectively. The sliding of the sliding rod (531) drives the first link (51) and the second link (52) to rotate, so as to realize the folding or unfolding of the base frame (3) and the handrail frame (4).

4. The improved handcart according to claim 3, characterized in that: The linkage assembly (53) further includes a connector (532), which is disposed between the first link (51) and the sliding rod (531). One end of the connector (532) is hinged to the first link (51), and the other end of the connector (532) is hinged to the sliding rod (531). The sliding rod (531) drives the first link (51) through the connector (532) to realize the folding or unfolding of the base frame (3).

5. The improved handcart according to claim 3, characterized in that: The front wheel bracket (1) and the rear wheel bracket (2) are respectively provided with guide structures between them and the sliding rod (531). The guide structure includes a guide portion (5311) provided on one side of the sliding rod (531) and a guide groove (21) provided on one side wall of the front wheel bracket (1) and the rear wheel bracket (2). The sliding rod (531) protrudes outward along the sliding direction of the sliding rod (531), and the sliding rod (531) cooperates with the guide groove (21) through the guide part (5311).

6. The improved handcart according to claim 3, characterized in that: The handrail (4) includes a first support (43) and at least one pair of first tubes (41) and second tubes (42). One end of the first tube (41) and the second tube (42) are respectively hinged to the first support (43). A synchronization structure is provided between the second tube (42) and the first support (43). The synchronization structure includes a linkage rod (44) and a slot (431). The slot (431) is provided on the first support (43). One end of the linkage rod (44) is hinged to one end of the second tube (42). The other end of the linkage rod (44) can be moved on the slot (431) through a connector. When the second tube (42) is folded, the linkage rod (44) is positioned at the first position of the slot (431) through the connector. When the second tube (42) is unfolded, the linkage rod (44) is positioned at the second position of the slot (431) through the connector.

7. The improved handcart according to claim 3, characterized in that: The handcart also includes a drive structure (6), which is disposed on any one of the front wheel bracket (1), the rear wheel bracket (2), the base frame (3) or the handrail frame (4); wherein the linkage assembly (53) is driven by the drive structure (6) to drive the base frame (3) and / or the handrail frame (4) to rotate.

8. The improved handcart according to claim 7, characterized in that: The drive structure (6) includes a push handle that can be mounted on the front wheel bracket (1) or the rear wheel bracket (2). A fourth link (7) is hinged between the sliding rod (531) and the push handle. When the push handle rotates, the sliding rod (531) is driven to slide through the fourth link (7).

9. The improved handcart according to claim 7, characterized in that: At least two base frames (3) are provided, and at least two base frames (3) are symmetrically arranged between the front wheel bracket (1) and the rear wheel bracket (2). The drive structure (6) includes a rotating joint (61) provided on one end of the two base frames (3), a joint tooth (62) that engages with the tooth on the rotating joint (61), and an unlocking component that controls the axial movement of the joint tooth (62). The base frame (3) is provided with a plurality of spaced support members (31). The unlocking component includes a traction member (63) and a pull handle (64) that drives the traction member (63) to move. The front and rear ends of the traction member (63) are connected to the joint tooth (62), and the pull handle (64) is provided on the support member (31).

10. The improved handcart according to claim 9, characterized in that: An elastic reset member is provided between the rotating joint (61) and the joint tooth (62). By driving the pull handle (64), the joint tooth (62) is displaced, so that the joint tooth (62) engages with the tooth on the rotating joint (61) and squeezes the elastic reset member, thereby causing the two base frames (3) to rotate relative to each other.

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