Trolley frame with volume increasing function, and trolley

Abstract

A trolley frame (100) with a volume increasing function, and a trolley (1000). The trolley frame (100) with a volume increasing function comprises a plurality of supporting tubes (10), at least one telescopic unit (15), a bottom folding frame (13) connected to the plurality of supporting tubes (10), and a plurality of wheel assemblies (14) provided at the lower portions of the supporting tubes (10); the at least one telescopic unit (15) is connected to the adjacent supporting tubes (10); the telescopic unit (15) extends to unfold the trolley frame (100) with a volume increasing function, and the telescopic unit (15) retracts to fold the trolley frame (100) with a volume increasing function; the trolley frame (100) with a volume increasing function further comprises a plurality of sliding tube assemblies (20); the sliding tube assemblies (20) are inserted into the supporting tubes (10); the telescopic units (15) are connected to the sliding tube assemblies (20) at least by means of locking devices (39); and when the locking devices (39) lock the sliding tube assemblies (20), the sliding tube assemblies (20) can ascend and descend along with extension and retraction of the telescopic unit (15). According to the trolley frame (100) with a volume increasing function, the volume increasing function is linked with the unfolding and folding steps, so that the volume is automatically increased during unfolding, the height is automatically decreased during folding to reduce the packaging volume, and the volume can be selected not to be increased. The trolley frame can be directly unfolded in both the volume increased state and the non-volume increased state, and the two states can be switched conveniently. The concealed design of the sliding tube assemblies (20) improves the overall appearance.

Description

Expandable cart frame and cart

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202420283155.X, filed with the Patent Office of China on February 6, 2024, entitled “A Capacity Expandable Cart Frame and Cart,” the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present disclosure relates to the technical field of hand-pull carts, and in particular to an expandable cart frame and a cart. Background Art

[0004] Folding carts are designed to transport items, providing convenience for everyday outdoor activities and tasks like carrying goods. Whether out and about, or at a store or shopping mall, customers often need a cart to transport goods to their destination. This destination may be nearby, such as a temporary parking lot, or quite far away, such as a residential area accessible only by pedestrian, road, public transportation, or a combination thereof. Consequently, small, lightweight, foldable carts are a common means of transportation in today's society.

[0005] There are many functions of carts in the prior art. For example, there are carts with a folding function, which can be folded and stored when not in use, reducing the floor space and facilitating storage. There are also some carts with an expandable function, such as increasing the height of the cart to increase its transport capacity.

[0006] In existing carts, after increasing the height to increase the volume, the height cannot be reduced when it is needed to be folded, resulting in a large packaging volume and inconvenient storage. In addition, the expansion structure of existing carts cannot be hidden, making it inconvenient to switch when the expansion is not needed, which affects the overall appearance of the cart. Therefore, it is necessary to design a cart that can be easily folded when expanding and the expansion structure can be well hidden when not expanding.

[0007] Utility Model Content

[0008] The present disclosure provides an expandable cart frame and a cart, which can link the volume increase function with the opening and folding steps, so that the volume is automatically increased when opening, and the height is automatically lowered to reduce the packaging volume when folding. It is also possible to choose not to increase the volume.

[0009] The embodiments of the present disclosure may be implemented as follows:

[0010] An expandable cart frame includes a plurality of support tubes, at least one telescopic unit, a bottom folding frame connecting the plurality of support tubes, and a plurality of wheel assemblies arranged at the lower parts of the support tubes. At least one telescopic unit is connected to adjacent support tubes. The telescopic unit extends to expand the expandable cart frame, and contracts to fold the expandable cart frame. The expandable cart frame also includes a plurality of sliding tube assemblies. The sliding tube assemblies are inserted into the support tubes. The telescopic units are connected to the sliding tube assemblies via at least a locking device. When the locking device locks the sliding tube assemblies, the sliding tube assemblies can be raised and lowered as the telescopic units extend and retract.

[0011] Optionally, a plurality of telescopic units are provided, a plurality of support tubes are connected to form a frame through the plurality of telescopic units, and a plurality of sliding tube assemblies are provided in one-to-one correspondence with the plurality of support tubes.

[0012] Optionally, the telescopic unit includes two first telescopic units arranged at the front and rear ends of the cart frame and two second telescopic units arranged on both sides of the cart frame. A fixed connector located at the end of the support tube and a movable connector arranged below the fixed connector are installed on the support tube. The movable connector is slidably connected to the support tube, and the first telescopic unit and the second telescopic unit are connected to the support tube through the movable connector and the fixed connector.

[0013] Optionally, the fixed device is a movable connecting part, which includes a movable sleeve, an operating part and an elastic part. The movable sleeve and the operating part are mounted on the support tube. The movable sleeve is provided with a mounting groove with one end passing through its side wall. The operating part is slidably connected in the mounting groove along the radial direction of the movable sleeve. An elastic part is connected between the operating part and the mounting groove. The operating part is configured to extend one end of the movable sleeve out of the movable sleeve under the action of the elastic force of the elastic part.

[0014] Optionally, a vertical opening groove is provided on one side of the support tube, a positioning block is provided on the operating member and is located in the opening groove, and at least one positioning groove is provided on the side wall of the sliding tube assembly. The positioning block can be inserted into the positioning groove in the support tube to support the sliding tube assembly, and the sliding tube assembly and the movable connecting member can move up and down along the support tube together with the extension and contraction of the telescopic unit. Pressing the operating member causes the positioning block to disengage from the positioning groove in the radial direction to release the support for the sliding tube assembly.

[0015] Optionally, one end of the elastic member is sleeved on the positioning block.

[0016] Optionally, there are multiple positioning grooves, which are spaced apart along the axial direction of the sliding tube assembly.

[0017] Optionally, the positioning groove is an annular structure.

[0018] Optionally, one end of the control member forms a column, a connecting hole configured to install the column is formed in the installation groove, and the elastic member is sleeved on the column and placed in the connecting hole together with the column.

[0019] Optionally, the fixed connection member includes a fixed sleeve, which is sleeved on the upper end of the support tube, and one end of the sliding tube assembly can pass through the fixed sleeve and enter the support tube.

[0020] Optionally, the sliding tube assembly includes a sliding tube, a connecting plug and an upper cap, the connecting plug and the upper cap are respectively arranged at the two ends of the sliding tube and are arranged to be detachably connected to the sliding tube, the length of the support tube is not less than the length of the sliding tube assembly, and the upper cap is configured to connect flexible fabric.

[0021] Optionally, the sliding tube assembly is configured to coincide with the axis of the support tube in an assembled state.

[0022] An embodiment of the present disclosure further discloses a cart, comprising a frame and a flexible fabric connected to the frame, wherein the frame adopts any of the above-mentioned expansion cart frames, and the flexible fabric is connected to one end of a sliding tube assembly.

[0023] Compared with the prior art, the beneficial effects of the utility model disclosed herein include, for example:

[0024] A sliding tube assembly is provided for capacity expansion, which can increase the height of the cart and thus achieve the purpose of capacity expansion. The sliding tube assembly is inserted into the support tube and can be completely or nearly completely inserted into the support tube for concealment as needed during use, further increasing the capacity expansion range. Moreover, the sliding tube assembly can be linked with the folding function of the cart, achieving the capacity expansion effect while being able to fold smoothly at the same time, simplifying the operation steps.

[0025] These features and advantages of the present disclosure will be detailed in the following detailed description and accompanying drawings. The preferred embodiments or means of the present disclosure will be fully illustrated in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present disclosure. Furthermore, although multiple features, elements, and components may be present and are labeled with different symbols or numbers for convenience, they all represent components with the same or similar structure or function. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0027] The present disclosure will be further described below with reference to the accompanying drawings:

[0028] FIG1 is a structural diagram of a sliding tube assembly and one of the support tube assemblies of the present disclosure;

[0029] FIG2 is a structural diagram of the sliding tube assembly and the support tube assembly disclosed herein;

[0030] FIG3 is a partial enlarged view of FIG1 of the present disclosure;

[0031] FIG4 is a partial enlarged view of FIG2 of the present disclosure;

[0032] FIG5 is a structural diagram of a sliding tube assembly of the present disclosure;

[0033] FIG6 is a structural diagram of a control member disclosed herein;

[0034] FIG7 is a structural diagram of a support tube according to the present disclosure;

[0035] FIG8 is a diagram of the cart of the present invention in an expanded state;

[0036] FIG9 is a diagram showing an intermediate state of the stroller of the present invention when it is expanded and folded;

[0037] FIG10 is a diagram of the stroller of the present invention in an expanded state when not expanded;

[0038] FIG11 is a schematic structural diagram of the cart disclosed in the present invention.

[0039] Among them, 10, support tube; 101, open slot; 11, first telescopic unit; 12, second telescopic unit; 13, bottom folding frame; 14, wheel assembly; 15, telescopic unit; 17, frame; 20, sliding tube assembly; 21, sliding tube; 22, connecting plug; 23, upper cap; 24, positioning slot; 30, fixed connector; 31, fixed sleeve; 39, locking device; 40, movable connector; 41, movable sleeve; 411, mounting slot; 412, connecting hole; 42, control member; 43, elastic member; 44, positioning block; 45, column; 100, expansion trolley frame; 200, frame; 300, flexible fabric; 1000 - trolley. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all of them. Generally, the components of the embodiments of the present disclosure described and shown in the drawings herein can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the present disclosure as claimed, but merely represents selected embodiments of the present disclosure. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without creative effort shall fall within the scope of protection of the present disclosure.

[0042] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0043] In the description of the present disclosure, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the invented product is usually placed when used. It is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0044] In addition, the terms "first", "second", "third", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0045] Furthermore, the use of terms such as "horizontal," "vertical," and "overhanging" does not necessarily imply that the component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0046] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on the specific circumstances.

[0047] It should be noted that, in the absence of conflict, the features in the embodiments of the present disclosure may be combined with each other.

[0048] The present disclosure provides an expandable cart frame 100 for a cart 1000, see Figures 1, 2, 8, and 9, comprising a plurality of support tubes 10, at least one telescopic unit 15, a bottom folding frame 13 connecting all the support tubes 10, and a plurality of wheel assemblies 14 arranged on the support tubes 10. In this embodiment, the support tubes 10 are arranged vertically, and the plurality of support tubes 10 are distributed circumferentially, and at least one telescopic unit 15 is connected to the side walls of two adjacent support tubes 10; when in use, the telescopic unit 15 is extended to expand the expandable cart frame 100, and the telescopic unit 15 is retracted to fold the expandable cart frame 100; the expandable cart frame 100 also includes a plurality of sliding tube assemblies 20, which are inserted into the support tubes 10, and the telescopic units 15 are connected to the sliding tube assemblies 20 via at least a locking device 39. When the locking device 39 locks the sliding tube assembly 20, the sliding tube assembly 20 can be raised and lowered as the telescopic unit 15 is extended and retracted.

[0049] It is worth noting that when the telescopic unit 15 is extended or contracted, the volume it occupies increases or decreases, thereby driving the entire expandable push cart frame 100 to switch between the expanded and collapsed states. In addition, during the insertion and mating process of the sliding tube assembly 20 and the support tube 10, the two can be ensured to correspond one to one.

[0050] In the specific design, the sliding tube assembly 20 and the support tube 10 can be made of pipes with different cross-sections, such as round tubes and square tubes. During assembly, the axes of the sliding tube assembly 20 and the support tube 10 coincide, and the gap between the outer wall of the sliding tube assembly 20 and the inner wall of the support tube 10 is minimized. This ensures smooth sliding while improving the stability of the sliding tube assembly 20 during its lifting and lowering movement within the support tube 10. The sliding tube assembly 20 can be concealed within the support tube 10, enhancing the overall appearance of the cart 1000 while expanding its capacity. The sliding tube assembly 20 can rise and fall with the extension and retraction of the telescopic unit 15, achieving linkage with the folding function of the cart 1000 and enhancing the integrity of the cart 1000. Furthermore, when folding and storing, there is no need to first lower the height of the cart 1000 before folding; the height added by the expansion can be lowered simultaneously during folding, making operation convenient.

[0051] The telescopic unit 15 can be arranged on the left and right sides of the expansion cart frame 100 or on the front or rear side of the frame. When the telescopic unit 15 is arranged on the left and right sides of the expansion cart frame 100 (not arranged on the front and rear sides), the expansion cart frame 100 can only be expanded or folded in the length direction; when the telescopic unit 15 is only arranged on the front or rear side of the expansion cart frame 100 (not arranged on the left and right sides), the expansion cart frame 100 can only be expanded or folded in the width direction.

[0052] The present disclosure provides a plurality of telescopic units 15, and a plurality of support tubes 10 are connected to form a frame 17 through the plurality of telescopic units 15 to form an integrated structure. A plurality of sliding tube assemblies 20 are arranged in a one-to-one correspondence with the plurality of support tubes 10, so that the number of sliding tube assemblies 20 and support tubes 10 is consistent. In this way, when expanding, each support tube 10 is installed with a sliding tube assembly 20 for increasing the height, so that the soft surface of the vehicle body after the increase has multiple support points, thereby improving the stability of the entire vehicle after the expansion.

[0053] The folding and stowing function of the present disclosure is achieved in the following manner: a fixed connector 30 is mounted on the support tube 10 at the end of the support tube 10, and a movable connector 40 is disposed below the fixed connector 30. The movable connector 40 is slidably connected to the support tube 10. The first telescopic unit 11 and the second telescopic unit 12 are connected to the support tube 10 via the movable connector 40 and the fixed connector 30. Both the fixed connector 30 and the movable connector 40 are mounted on the support tube 10. During folding and stowage, referring to FIG8 , since the telescopic unit 15 is a structure with hinged connecting rods, the folding action is accommodated by the lifting and lowering of the movable connector 40 during the stowage process. It should be noted that the telescopic unit 15 in the present disclosure includes two first telescopic units 11 respectively arranged at the front end and the rear end of the expansion cart frame 100 and two second telescopic units 12 arranged on both sides of the expansion cart frame 100. When folding, the extension and contraction of the first telescopic unit 11 can make the expansion cart frame 100 expand or fold in the width direction, and the extension and contraction of the second telescopic unit 12 can make the expansion cart frame 100 expand or fold in the length direction. In this way, when in use, the expansion and folding actions of the expansion cart frame 100 in the width and length directions are independent of each other, and can be operated in a single direction. Of course, it can also achieve simultaneous expansion or folding in the length and width directions, further enriching the use scenarios of the expansion cart frame 100.

[0054] Specifically, the same first telescopic unit 11 can be connected to the fixed connection member 30 and the movable connection member 40 at the same time, and the same second telescopic unit 12 can be connected to the fixed connection member 30 and the movable connection member 40 at the same time.

[0055] Optionally, in actual application, the telescopic unit 15 can be one, two or more pairs of cross rods, or cross rods can be combined with other known folding technologies such as hinged rods or sliding rods to form a hinge structure that is hinged to each other. The contraction of the telescopic unit 15 in the present disclosure realizes the bundle-type folding of the cart 1000.

[0056] Optionally, the locking device 39 is a movable connecting member 40, and the linkage between the sliding tube assembly 20 and the folding function is achieved by the movable connecting member 40, referring to Figures 3, 4, and 6. The movable connecting member 40 includes a movable sleeve 41, an operating member 42, and an elastic member 43. The movable sleeve 41 and the operating member 42 (see Figure 6, the operating member 42 has an annular structure, which can improve the stability of the installation) are sleeved on the support tube 10. In actual setting, the gap between the inner wall of the movable sleeve 41 and the outer wall of the support tube 10 is set as small as possible, so that the movable connecting member 40 can stably move up and down along the support tube 10. A mounting groove 411 with one end passing through its side wall is provided on the movable sleeve 41, and the operating member 42 is slidably connected in the mounting groove 411 along the radial direction of the movable sleeve 41. An elastic member 43 is connected between the operating member 42 and the mounting groove 411, and the operating member 42 is set to extend one end out of the movable sleeve 41 under the action of the elastic member 43. In the initial state, a portion of the operating member 42 protrudes from the movable sleeve 41 under the action of the elastic force of the elastic member 43, which facilitates the operation of the staff. The operator presses the end of the operating member 42 protruding from the movable sleeve 41 to make the operating member 42 slide along the radial direction of the movable sleeve 41. At this time, the elastic member 43 is compressed; when the operating member 42 is released, the operating member 42 will be restored to the initial state under the elastic force of the elastic member 43.

[0057] It is noteworthy that the installation groove 411 is formed by a depression on one side of the movable sleeve 41 , so that one end of the installation groove 411 passes through a side wall of the movable sleeve 41 .

[0058] Optionally, in addition to the structure of the operating member 42, the locking device 39 can also adopt existing locking means such as limit pins and elastic buckles. The elastic member 43 can adopt elastic components such as springs, shrapnel, disc springs, torsion springs, etc. in specific use.

[0059] Referring to Figures 1 and 7 , the present invention includes a vertical opening 101 on one side of the support tube 10 . The opening 101 connects the inner cavity of the support tube 10 to the outside. A positioning block 44 is provided on the operating member 42 and is positioned within the opening 101 . The sliding tube assembly 20 includes a sliding tube 21 , and a positioning slot 24 is provided on the sidewall of the sliding tube 21 . The positioning block 44 can be engaged within the positioning slot 24 within the support tube 10 to provide support for the sliding tube 21 , allowing the sliding tube assembly 20 and the movable connecting member 40 to move up and down along the support tube 10 as the telescopic unit extends and retracts. The positioning block 44 can be radially disengaged from the positioning slot 24 by pressing the operating member 42 with external force, thereby releasing support for the sliding tube 21 . Furthermore, one end of the elastic member 43 is sleeved onto the positioning block 44 .

[0060] It is worth noting that the opening slot 101 extends in the vertical direction, the vertical direction can be regarded as the axial direction of the support tube 10 , and the opening direction of the opening slot 101 can be regarded as the radial direction of the support tube 10 .

[0061] When the capacity of the cart frame 100 needs to be expanded, the overall height of the cart 1000 is increased by sliding the tube assembly 20 . When the positioning groove 24 on the sliding tube 21 moves to the position corresponding to the positioning block 44, the operating member 42 is released. At this time, the operating member 42 will be reset under the action of the elastic member 43 and the positioning block 44 will be reset to move into the inner cavity of the support tube 10 and snap into the positioning groove 24 (in the specific design, in order to simplify the operation, a chamfered or rounded transition guide portion can be provided at the end of the positioning block 44 or the sliding tube 21. In this way, when the sliding tube 21 is installed, the radial movement of the operating member 42 can be pushed by the transition guide portion, which can reduce the pressing operation). In this way, the sliding tube 21 is connected to the movable connecting member 40 as a whole through the matching structure of the positioning block 44 and the positioning groove 24. For example, the cart has four support tubes 10 (correspondingly, four sliding tube assemblies 20 are also provided), so the above process needs to be repeated four times during assembly. When the four sliding tube assemblies 20 and the support tubes 10 are assembled, the sliding tube assembly 20 can move up and down together with the movable connecting member 40 as the telescopic unit extends and contracts, thereby realizing the linkage of expansion and folding functions.

[0062] When the cart 1000 is in the expanded state (see FIG8 ), the sliding tube assembly 20 increases the overall height of the cart, thereby increasing its capacity. When the cart 1000 is folded (see FIG9 ), the sliding tube 21 moves downward along with the movable connector 40, simultaneously lowering the overall height during folding, thereby achieving a linkage between the expansion and folding functions. When the expandable cart frame 100 is folded and stored, the cart 1000 can be stored as normal, without the additional operation required by the expansion components, making it convenient to use.

[0063] Optionally, a plurality of positioning slots 24 are provided and spaced apart along the axial direction of the sliding tube assembly 20. By providing multiple positioning slots 24, different expansion ranges can be adjusted. Specifically, the sliding tube assembly 20 can be locked with the movable connector 40 at different positions. This allows the maximum expansion height of the cart 1000 to be varied to accommodate a variety of application scenarios, such as when the cart 1000 requires a certain expansion capacity and is used in a sports venue with height restrictions.

[0064] Optionally, the positioning groove 24 is designed as an annular structure. In this way, the positioning block 44 on the operating member 42 can be easily snapped into the positioning groove 24 in any orientation of the sliding tube assembly 20. In this way, when the sliding tube 21 is inserted into the support tube 10, there is no need to consider the relative position relationship between the sliding tube 21 and the support tube 10, thereby improving assembly efficiency. Optionally, the positioning groove 24 can also be configured as a non-annular structure. For example, the positioning groove 24 is only provided in a certain orientation on the side wall of the sliding tube assembly 20. In this case, in order to ensure that the positioning block 44 can snap into the positioning groove 24, it is necessary to add a guide / limiting device to the sliding tube assembly 20 (to limit the relative position of the sliding tube assembly 20 and the support tube 10) so that the positioning groove 24 can correspond to the position of the positioning block 44.

[0065] Optionally, the sliding tube assembly 20 includes a sliding tube 21, a connecting plug 22, and an upper cap 23. The connecting plug 22 and upper cap 23 are respectively disposed at the two ends of the sliding tube 21 and are configured to be detachably connected to the sliding tube 21. The length of the support tube 10 is not less than that of the sliding tube assembly 20, and the upper cap 23 is configured to connect to the flexible fabric 300. The end of the sliding tube assembly 20 with the connecting plug 22 is inserted into the support tube 10. In actual use, the positioning groove 24 can be provided on the side wall of the sliding tube 21, or alternatively, on the side wall of the connecting plug 22. Because the connecting plug 22 and upper cap 23 are more easily damaged than the sliding tube 21 during use, a detachable structure facilitates their replacement. Specifically, the connecting plug 22 and upper cap 23 can be configured to be threadedly connected to the sliding tube 21, making assembly and disassembly easier.

[0066] The positioning block 44 is inserted into the positioning groove 24 under the action of the elastic member 43, and the matching position of the positioning groove 24 and the positioning block 44 is located inside the support tube 10. The specific internal situation cannot be observed from the outside. During the actual installation process, when the positioning block 44 is inserted into the positioning groove 24, it is easy to get stuck at the edge of the positioning groove 24 and become unable to enter the positioning groove 24. In order to solve this blocking problem, a guide groove or an arc transition structure can be added to the upper and lower edges of the opening of the positioning groove 24. The guide groove or the arc transition structure increases the opening size of the positioning groove 24, making it easier for the positioning block 44 to enter the positioning groove 24 and avoid blocking.

[0067] To enhance the operational stability of the control member 42, as shown in FIG5 , a post 45 is formed at one end of the control member 42. A connection hole configured to receive the post 45 is formed within the mounting slot. The elastic member 43 is fitted onto the post 45. This positioning of the elastic member 43 within the post 45 prevents the elastic member 43 from bending or twisting during frequent operation, thereby enhancing the stability of the control member 42. Furthermore, during design, the mounting slot width and height are configured to match the width of the control member 42, ensuring smooth sliding of the control member 42 without causing any shaking, thereby enhancing the stability of the control member 42.

[0068] The fixed connector 30 includes a fixed sleeve 31, which is secured to the upper end of the support tube 10 in a sleeve-like manner. One end of the sliding tube 21 can pass through the fixed sleeve and enter the support tube 10. The other end of the sliding tube 21 is provided with an upper cap 23 configured to connect to a soft surface. The upper cap 23 connects to the soft surface on the upper part of the vehicle body. In actual use, the upper cap 23 can also be inserted into the fixed sleeve 31 or the support tube 10, with the top of the upper cap 23 flush with the end of the fixed sleeve 31. In this way, the sliding tube assembly 20 is completely concealed within the support tube 10 (of course, in a specific configuration, the length of the support tube 10 should be no less than that of the sliding tube assembly 20), improving the overall appearance.

[0069] It can be seen that when expansion is not needed, the sliding tube assembly 20 can be completely hidden. The specific operation is: pressing the operating member 42 to disengage the positioning block 44 on the operating member 42 from the positioning groove 24 on the sliding tube 21, releasing the support of the movable connecting member 40 on the sliding tube assembly 20, pressing the sliding tube assembly 20 or allowing the sliding tube assembly 20 to move downward under the action of its own gravity, and completely hiding the sliding tube 21 within the support tube 10. At this time, the cart does not have the expansion function; when expansion is needed again, it is only necessary to pull up the sliding tube assembly 20 by lifting the soft surface on the cart body and re-engage the positioning block 44 in the positioning groove 24. Switching between the expansion and non-expansion states is convenient. Referring to Figure 10, which is a diagram of the cart in the expanded state when not expanding, it can be seen that the expansion and folding operations of the cart body when not expanding are consistent with the expansion and folding operations when expanding, which is convenient to operate.

[0070] Referring to FIG11 , the present disclosure further discloses a cart 1000 comprising a frame 200 and a flexible fabric 300. Specifically, the frame 200 may be the aforementioned expandable cart frame 100. In actual configuration, the flexible fabric 300 is detachably connected to the upper cap 23 of the sliding tube assembly 20, facilitating assembly of the cart 1000 and removal, replacement, or maintenance of the flexible fabric 300. During use, the flexible fabric 300 moves with the sliding tube assembly 20. When the sliding tube assembly 20 reaches its lowest point, the lower end of the flexible fabric 300 is flush with the upper end of the support tube 10.

[0071] This cart 1000, in addition to conventional carts, features a volume-increasing function, and the user can flexibly select whether to enable or disable this function. If enabled, it can be linked to the opening and closing steps of the cart 1000, automatically increasing the volume during opening and lowering the height to reduce the packaging volume during closing. If the volume-increasing function is disabled, the sliding tube assembly 20 does not move with the movable connector; the cart 1000 can be directly expanded and collapsed without interfering with each other. Furthermore, the sliding tube assembly 20 can be concealed during expansion and collapse, as well as when expansion is not required, improving the overall compactness and appearance of the structure.

[0072] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Those skilled in the art should understand that the present disclosure includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modifications that do not deviate from the functional and structural principles of the present disclosure are included within the scope of the claims. Industrial Applicability

[0073] The expandable stroller frame and the stroller are provided with a leg tube on one side of the middle bracket, so that a stable triangular structure is formed between the leg tube, the middle bracket and the ground, thereby ensuring the stability of the folding chair base formed by the leg tube and the middle bracket, thereby improving the stability of the folding chair structure in use.

Claims

1. An expandable cart frame (100), comprising a plurality of support tubes (10), at least one telescopic unit (15), a bottom folding frame (13) connecting the plurality of support tubes (10), and a plurality of wheel assemblies (14) arranged at the lower portion of the support tubes (10), at least one telescopic unit (15) connecting two adjacent support tubes (10); the telescopic unit extends to expand the expandable cart frame, and contracts to fold the expandable cart frame (100); characterized in that The expansion cart frame (100) further comprises a plurality of sliding tube assemblies (20), wherein the sliding tube assemblies (20) are inserted into the support tube (10), and the telescopic unit (15) is connected to the sliding tube assemblies (20) at least via a locking device (39). When the locking device (39) locks the sliding tube assemblies (20), the sliding tube assemblies (20) can be raised and lowered as the telescopic unit (15) is extended or retracted.

2. The expandable push cart frame (100) according to claim 1, characterized in that: The telescopic units (15) are provided in plurality, the plurality of support tubes (10) are connected to form a frame (17) through the plurality of telescopic units (15), and the plurality of sliding tube assemblies (20) are provided in one-to-one correspondence with the plurality of support tubes (10).

3. The expandable push cart frame (100) according to claim 1 or 2, characterized in that: The telescopic unit (15) includes two first telescopic units (11) arranged at the front and rear ends of the expansion cart frame (100) and two second telescopic units (12) arranged on both sides of the expansion cart frame (100); a fixed connection member (30) located at the end of the support tube (10) and a movable connection member (40) arranged below the fixed connection member (30) are installed on the support tube (10); the movable connection member (40) is slidably connected to the support tube (10); the first telescopic unit (11) and the second telescopic unit (12) are connected to the support tube (10) through the movable connection member (40) and the fixed connection member (30).

4. The expandable push cart frame (100) according to claim 3, characterized in that: The locking device (39) is a movable connecting member (40), which includes a movable sleeve (41), an operating member (42) and an elastic member (43). The movable sleeve (41) and the operating member (42) are mounted on the telescopic support tube (10). The movable sleeve (41) is provided with a mounting groove (411) with one end penetrating the side wall thereof. The operating member (42) is slidably connected to the mounting groove (411) along the radial direction of the movable sleeve (41). The elastic member (43) is connected between the operating member (42) and the mounting groove (411). The operating member (42) is configured to extend out of the movable sleeve (41) at one end under the elastic force of the elastic member (43).

5. The expandable push cart frame (100) according to claim 4, characterized in that: A vertical opening groove (101) is provided on one side of the support tube (10), and a positioning block (44) is provided on the operating member (42) and is located in the opening groove (101). At least one positioning groove (24) is provided on the side wall of the sliding tube assembly (20). The positioning block (44) can be inserted into the positioning groove (24) in the support tube (10) to support the sliding tube assembly (20), and enable the sliding tube assembly (20) and the movable connecting member (40) to move up and down along the support tube (10) along with the extension and contraction of the telescopic unit (15). Pressing the operating member (42) causes the positioning block (44) to disengage from the positioning groove (24) in the radial direction to release the support for the sliding tube assembly (20).

6. The expandable push cart frame (100) according to claim 5, characterized in that: One end of the elastic member (43) is sleeved on the positioning block (44).

7. The expandable push cart frame (100) according to claim 5 or 6, characterized in that: The number of the positioning grooves (24) is multiple and they are distributed at intervals along the axial direction of the sliding tube assembly (20).

8. The expandable push cart frame (100) according to any one of claims 5 to 7, characterized in that: The positioning groove (24) is an annular structure.

9. The expandable push cart frame (100) according to any one of claims 4 to 8, characterized in that: A column (45) is formed at one end of the operating member (42), a connecting hole (412) configured to install the column (45) is formed in the mounting groove (411), and the elastic member (43) is sleeved on the column (45) and placed in the connecting hole (412) together with the column (45).

10. The expandable push cart frame (100) according to any one of claims 3 to 9, characterized in that: The fixed connection member (30) includes a fixed sleeve (31), which is sleeved on the upper end of the support tube (10), and one end of the sliding tube assembly (20) can pass through the fixed sleeve (31) and enter the support tube (10).

11. The expandable push cart frame (100) according to any one of claims 1 to 10, characterized in that: The sliding tube assembly (20) comprises a sliding tube (21), a connecting plug (22) and an upper cap (23). The connecting plug (22) and the upper cap (23) are arranged at two ends of the sliding tube (21) and are arranged to be detachably connected to the sliding tube (21). The length of the supporting tube (10) is not less than the length of the sliding tube assembly (20). The upper cap (23) is configured to connect to a flexible fabric.

12. The expandable push cart frame (100) according to any one of claims 1 to 10, characterized in that: The sliding tube assembly (20) is configured to coincide with the axis of the support tube (10) in an assembled state.

13. A cart (1000), comprising a frame (200) and a flexible fabric (300) connected to the frame (200), characterized in that: The frame (200) adopts the expandable push frame (100) according to any one of claims 1 to 12, and the flexible fabric (300) is connected to one end of the sliding tube assembly (20).

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